JP2013067286A - Bicycle hub unit, power-assisted bicycle using the same, and two-wheeled electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and compact device while improving strength to bending load.SOLUTION: In a transmission mechanism part 30 in a hub 10 of a bicycle hub unit, a speed-reducing mechanism part 40 and a drive motor 18 are arranged in parallel along one axle 15 composed of single member. The transmission mechanism part 30 transmits human drive power to a hub case 11, and the speed-reducing mechanism part 40 transmits the drive power of the drive motor 18 to the hub case. The transmission mechanism part 30 includes a transmission sun gear 30a, a transmission planetary gear 30b, and a transmission planetary carrier 30c. The member to be output to the hub case 11 is the transmission planetary carrier 30c. The speed-reducing mechanism 40 includes a speed-reducing sun gear 40a, a speed-reducing planetary gear 40b, and a speed-reducing outer ring gear 40d. The member to be output to the hub case 11 is the transmission planetary carrier 30c that holds the speed-reducing planetary gear 40b. Between the transmission planetary carrier 30c and the hub case 11, an output transmission member 50 is arranged to integrally rotate the transmission planetary carrier 30c and the hub case 11.

Description

  The present invention relates to an electrically assisted bicycle or an electric motorcycle that adds an assisting force to a human power drive system by an electric motor, a bicycle hub unit used in the electrically assisted bicycle or an electric motorcycle, and an electrically assisted bicycle and an electric motor using the same. It relates to motorcycles.

  There are various types of bicycle transmissions. Under such circumstances, generally, a multi-stage sprocket is provided on the same axis of either the crankshaft or the rear axle, or both, and the speed is changed by moving the chain between the sprockets by a derailleur (exterior gear shifting). And a system (internal transmission) that changes gears by switching gears provided in the rear hub of the rear wheel that is a driving wheel.

  The exterior transmission has a simple structure and is lightweight, but it causes wear of the sprocket and the chain, and also causes the chain to come off. On the other hand, internal transmissions are often used in city cycles because they have excellent dust and water resistance and are maintenance-free.

  By the way, in an electrically assisted bicycle or an electric motorcycle (hereinafter collectively referred to as an electrically assisted bicycle) in which an assisting force is applied to a human power drive system by an electric motor, a driving wheel is installed in a rear hub of a rear wheel that is a drive wheel of the electrically assisted bicycle. Some have a motor, a speed reduction mechanism, and a speed change mechanism.

A so-called rear hub motor type battery-assisted bicycle provided with a motor at the rear hub can use either an exterior transmission or an interior transmission when combined with a transmission mechanism.
However, when the exterior transmission is used, the structure of the hub is mainly composed of the drive motor and the speed reduction mechanism, and thus becomes simple. However, there is a problem in maintenance due to the exterior transmission as described above. On the other hand, when an internal transmission is used, the hub structure is composed of a motor, a speed reduction mechanism, and a transmission mechanism, so the structure of the hub itself is complicated. This is advantageous.

At present, battery-assisted bicycles are developed mainly in the city cycle, and most of them adopt an internal transmission. Therefore, it is considered that it is desirable to use an internal transmission even in a rear hub motor type battery-assisted bicycle.
Examples of the structure of a battery-assisted bicycle provided with this type of internal transmission include those described in Patent Documents 1 and 2, for example.

In these structures, a drive motor (electric motor), a speed reduction mechanism, and a speed change mechanism are arranged in the rear hub. As a drive mechanism using a motor, a drive motor and a power system speed reduction mechanism for reducing the rotational speed of the drive motor are incorporated. As a human power input mechanism, an input sprocket is provided on the axle of the drive wheel, and a speed change mechanism and a speed reduction mechanism are arranged in this order from the axle toward the outer periphery.
The rear hub includes a rotating casing and a fixed casing. The human-powered input mechanism is disposed on the rotating casing side, and the driving mechanism using the driving motor is mainly disposed on the fixed casing side.

The human power given by the pedal is transmitted to the sprocket of the driving wheel by the chain, is shifted by the speed change mechanism, and rotates the driving wheel through the rotating casing. In addition, the driving force by the motor is decelerated by the speed reduction mechanism portion of the power system provided separately from the above-described transmission mechanism portion of the human power system, and then the human power driving force and the electric driving force are combined in the rotating casing, It is transmitted to the drive wheel.
At this time, the driving force by the human power converted into the electric signal and the electric signal of the running speed from the speed sensor are input to the control unit included in the battery-assisted bicycle, and the control unit is based on a predetermined condition. Then, a drive signal is output to control the motor.

  However, in these structures, the motor is disposed at a position eccentric from the axle center of the axle or at a position far away from the axle toward the outer diameter side. For this reason, there exists a problem that the outer diameter of a hub becomes large. If the outer diameter of the hub is large, the weight balance tends to deteriorate.

  In this regard, according to the structure described in Patent Documents 3 and 4, the reduction mechanism, the drive motor, and the transmission mechanism are arranged along the axis of the axle. Can be suppressed.

JP-A-9-58568 JP 2000-043780 A JP 2003-160089 A JP 2002-293285 A

  In Patent Document 3, the drive motor is disposed between the speed reduction mechanism and the speed change mechanism. In such a configuration, it is difficult to arrange the power supply and control wiring of the motor, and the structure is complicated. Furthermore, since the speed reduction mechanism and the speed change mechanism are independent, it is difficult to increase the number of gears.

  Further, in Patent Document 4, in consideration of the assemblability, the driving motor is disposed at one axial end, the input sprocket is disposed at the other axial end, the operation of assembling the driving motor and the speed reduction mechanism, and the hub case The work of assembling the internal transmission into the lid that closes the end face of the housing is a separate work, and then the assembly work is simplified by incorporating both. That is, the speed reduction mechanism portion and the speed change mechanism portion are completely configured as separate units.

In Patent Document 4, a partition plate extending radially inward from the inner surface of the hub case (lid body) is provided to partition the speed change mechanism portion and the speed reduction mechanism portion. This partition plate can prevent scattering due to the centrifugal force of grease on the transmission side. However, this partition plate cannot be coupled with other members at a portion near the axis, and there is a problem that it is difficult to hold grease on the lid side.
In addition, since the partition plate is provided, the speed change mechanism portion and the speed reduction mechanism portion require separate routes for transmitting the driving force to the hub case. Each route needs to be provided with a torque transmission part (gear, clutch cam surface, etc.). Since the space in the axial direction of the hub unit is limited, it is difficult to increase the number of shift stages in such a configuration in which the speed change mechanism and the speed reduction mechanism are separately provided, as in Patent Document 3.

Further, Patent Document 4 employs a structure in which a planetary carrier (reduction gear frame) is fixed with a screw to a motor housing that houses a drive motor, and the planetary carrier is a space near the axis in the hub case. Is separated into one end side and the other end side in the axial direction. For this reason, as for the axis | shaft of the hub motor unit (moving body unit) fixed to the flame | frame of a bicycle, the axial direction one end side and other end side are comprised by the separate member on both sides of the planet carrier.
In such a structure, it is disadvantageous to a bending load acting on the shaft of the hub motor unit (moving body unit), and there is also a demand for further improving the durability.

  In view of this, the first object of the present invention is to make the device compact in a configuration in which three mechanisms of a speed change mechanism, a speed reduction mechanism, and a drive motor are provided in parallel along the axis of the axle. The second problem is to improve the strength against the load.

  In order to solve the first problem, the present invention provides a bicycle hub unit in which a speed change mechanism portion, a speed reduction mechanism portion, and a drive motor are arranged in parallel in the axial direction of an axle inside the hub. The mechanism portion has a function of transmitting a driving force by human power input to the input means to the hub case, and the speed reduction mechanism portion has a function of transmitting the driving force input from the driving motor to the hub case. And the output member of the speed change mechanism portion and the output member of the speed reduction mechanism portion are configured by the same member or a member coupled so as to be integrally rotatable. The speed change mechanism portion, the output member of the speed reduction mechanism portion, and the hub case A bicycle hub unit characterized in that an output transmission member that allows the output member and the hub case to rotate together is provided therebetween.

  By making the output member of the speed reduction mechanism portion and the output member of the speed change mechanism portion a common member or a member coupled so as to be integrally rotatable with each other, the speed change mechanism portion and the speed reduction mechanism portion are completely connected as in the past. In addition, it is not necessary to arrange them on separate routes, and a partition plate for partitioning the speed change mechanism portion and the speed reduction mechanism portion becomes unnecessary. For this reason, it is possible to make the structure compact and inexpensive in the axle direction. Furthermore, there is no partition plate, and the speed change mechanism and the speed reduction mechanism can be assembled together.

  In addition, by providing a separate output transmission member between the output member of the speed change mechanism portion and the speed reduction mechanism portion and the hub case that rotates integrally with the drive wheel, the outer diameter of the output member can be kept small. it can. For this reason, manufacture of an output member can be simplified.

In this configuration, as the configuration of the speed change mechanism portion, various configurations having a function of transmitting a driving force by human power input to the input means to the hub case can be adopted. At least one transmission sun gear, a transmission planetary gear meshing with the transmission sun gear, and a transmission planetary gear holding the transmission planetary gear And a shift control mechanism that shifts the at least one transmission sun gear to be rotatable or non-rotatable around the axle with respect to the driving force from the input means. Can be adopted.
In addition, as a configuration of the speed reduction mechanism section, various configurations having a function of transmitting a driving force input from the drive motor to the hub case can be adopted. For example, the speed reduction mechanism section is configured by a planetary gear mechanism. A reduction gear sun gear that rotates integrally with the motor shaft of the drive motor and a reduction gear planetary gear that meshes with the reduction gear sun gear can be employed.

  In the above configuration in which the planetary gear mechanism is adopted as the configuration of the speed change mechanism portion and the speed reduction mechanism portion, the output member to the hub case of the speed change mechanism portion is the planetary carrier for the transmission, and to the hub case of the speed reduction mechanism portion. The output member can be constituted by the planetary carrier for transmission or a member that can rotate integrally with the planetary carrier for transmission.

In many cases, a planetary carrier for a transmission includes a pocket portion (concave portion) that holds a planetary gear for a transmission. In order to form this pocket portion, conventionally, the shape of the planetary carrier for transmission, particularly the connecting portion to the hub case where the greatest force acts, that is, the shape of the outer diameter portion (the portion corresponding to the output transmission member) However, due to press during forging and other reasons, the degree of freedom in design was limited such that the size could not be increased in the axial direction.
However, since a separate output transmission member is interposed between the planetary carrier for transmission and the hub case, the connecting portion of the member to the hub case can be formed in the output transmission member. For this reason, the freedom degree in the design of the planetary carrier for transmission increases, and the strength of the coupling portion with the hub case can be improved by increasing the size of the separate output transmission member in the axial direction.

At this time, the planetary gear for reduction gear is held by the planetary carrier for transmission that is an output member of the transmission mechanism portion to the hub case, whereby the planetary gear for transmission is transferred to the hub case of the reduction mechanism portion. Output member.
By holding the planetary gear for the speed reducer with the planetary gear for the transmission, the planetary carrier for the transmission can be used as a common output member for the transmission mechanism and the speed reduction mechanism. It becomes.

In order to solve the second problem, the present invention employs a configuration in which the axle is a single member that is both-end fixed to a bicycle frame.
Thus, the rigidity of the whole rear hub unit is ensured by fixing the axle to the frame with both ends supported. For this reason, the strength with respect to the bending load is improved, and the driving motor is firmly fixed to the axle and can be rotated stably.

  In each of these configurations, the output transmission member and the hub case, or the output transmission member and the planetary carrier for transmission, or both, are fixed so that they do not rotate relative to each other. It is possible to adopt a configuration in which a small backlash (backlash) is given to the connecting portion. By providing play at the joint, manufacturing errors between the two are allowed, and smooth rotation is possible even when there are manufacturing errors in the members.

Specifically, the hub case and the output transmission member are coupled to each other so that the hub case and the output transmission member are relatively movable in the axial direction and are integrally rotatable about the axis. It is possible to adopt a configuration in which the relative movement in the direction and the rotation around the axis are possible.
Further, the planetary carrier for transmission and the output transmission member are coupled to each other so as to be relatively movable in the axial direction and integrally rotatable about the axis, and in addition to or in place thereof, the planetary carrier for transmission and the output transmission member It is possible to adopt a configuration in which the members are coupled to each other so as to be relatively movable in the radial direction and integrally rotatable about the axis.

That is, it is desirable that the planetary gear is ideally driven concentrically, but actually, each gear includes a manufacturing error. For this reason, an excessive load may be applied to a specific gear due to the manufacturing error, and durability may be reduced.
Therefore, it is suitable to be able to absorb these manufacturing errors. Here, the planetary carrier for transmission and the output transmission member, which are constituted by separate members, and the planetary carrier for transmission and the output transmission member can be rotated together, while having a degree of freedom so as to be relatively movable in the radial direction. ing. Alternatively, each has a degree of freedom so as to be capable of relative movement in the axial direction while being able to rotate integrally. By the intervention of this degree of freedom, it is possible to achieve a gear arrangement with a balanced load in the planetary gear mechanism.

  Further, the transmission planetary carrier and the output transmission member may be coupled by a well-known method such as press-fitting, fitting, or spline coupling. For example, the transmission planetary carrier and the reduction planetary gear The structure which couple | bonds it through the planet carrier axis | shaft which supports can be employ | adopted.

  Here, for example, the structure of the speed change mechanism portion can be a reduction type including a direct connection state from the input member to the hub case. Further, the structure of the speed change mechanism portion may be a reduction type including a direct connection state from the input member to the hub case and a reduction state of two or more stages.

As a configuration of the shift control mechanism unit that switches two or more shift stages of the planetary gear mechanism, for example, a clutch member is provided between the sun gear for transmission and the axle, and this clutch member (first one-way clutch for transmission) The transmission sun gear can be shifted by switching between a state in which the transmission sun gear can rotate in one direction around the axle and a state in which the transmission sun gear cannot rotate.
In addition, for example, another clutch member is provided between the outer ring gear for transmission that is connected to the input means and meshes with the planetary gear for transmission, and the planetary carrier for transmission that holds the planetary gear for transmission. The transmission control mechanism switches the outer ring gear for transmission to a state in which it cannot rotate in one direction around the axis with respect to the planetary carrier for transmission, so that the constant speed (direct connection) state from the input means to the planetary carrier for transmission It is possible to change the speed.
Normally, a battery-assisted bicycle often travels with a top gear having the largest gear ratio (for example, the state of the third speed in the case of a three-speed shift). High stability and significant improvement in durability. In addition, by increasing the number of stages of the planetary gear and further providing the same number of sun gears according to the number of stages of the planetary gear, it is possible to increase the number of transmissions to 4, 5, and 6.

  As for the speed reduction mechanism, it is possible to achieve a high speed reduction ratio by using two-stage planetary gears having different numbers of teeth for the planetary gear mechanism of the speed reduction mechanism.

In each of these configurations, a switching clutch is provided between the outer ring gear for the reduction gear that meshes with the planetary gear for the reduction gear and the motor housing that holds the drive motor, so that the motor when the auxiliary motor does not operate is provided. The drag torque can be suppressed.
That is, the switching clutch is always engageable with the rotation of the planetary carrier for the speed reducer with respect to the motor housing when the bicycle moves forward by the input of the driving force from the driving motor, and the rotation of the switching clutch in the opposite direction. Then, the state is switched between the engageable state and the disengageable state by the input for instructing the switch transmitted from the outside. In conventional battery-assisted bicycles, there is a range of speeds that can be assisted by motor drive, and when the auxiliary motor does not operate due to speeds exceeding that range or due to battery exhaustion, etc., the motor is dragged by the speed reduction mechanism. There was a problem that the torque increased and the running resistance increased. However, such a drag torque problem can be solved by the intervention of the switching clutch.

  For example, a configuration in which the switching clutch is a two-way clutch can be employed. Further, as the switching clutch, for example, a roller clutch, a sprag clutch, or a clutch provided with a ratchet mechanism (a ratchet clutch) can be employed. By using a roller clutch or a sprag clutch for this two-way clutch, it becomes possible to reduce the amount of play, and by using a ratchet mechanism, the structure can be simplified.

  In the two-way clutch, when the driving force from the driving motor is applied, the outer ring gear for the reduction gear of the reduction mechanism unit is always in a state in which the two-way clutch cannot rotate with respect to the motor housing (see FIG. When the reverse torque is applied, it will idle.) Since the drive motor is rotationally fixed with respect to the axle, the reduction gear outer ring gear is also rotationally fixed. Accordingly, the driving force is transmitted from the drive motor to the output member (transmission planetary carrier) via the reduction gear sun gear and the reduction gear planetary gear, and the output member and the hub case are coupled so as to be integrally rotatable. Torque is transmitted to the drive wheels. Thereby, driving | running | working by auxiliary force is attained.

  Also, when the auxiliary force from the drive motor is unnecessary or cannot be obtained, such as when the battery is dead, the outer ring gear for the speed reducer is driven from the drive motor to the motor housing by the drive force of human power. It rotates in the opposite direction to when moving forward with force. In this state, the reduction gear outer ring gear of the reduction mechanism portion is made rotatable with respect to the motor housing, that is, the reduction gear planetary outer gear rotates idly with respect to the motor housing. As a result, comfortable driving without drag resistance of the drive motor is possible.

  Furthermore, for reverse input from the drive wheels when the bicycle travels by inertia, similarly, the outer ring gear for the speed reducer is in the opposite direction to that when moving forward with the drive force from the drive motor with respect to the motor housing. Rotate. In this state, the two-way clutch is engaged by an input transmitted from the outside, and the outer ring gear for the speed reducer of the speed reduction mechanism is made incapable of rotating with respect to the motor housing. Thereby, the reverse input from the drive wheel is transmitted to the drive motor via the speed reduction mechanism, and regenerative charging is possible.

  Therefore, only when regeneration is required, the switching clutch may be switched from the engageable state to the disengageable state, and the structure inside the hub can be simplified. The switching clutch can be switched by, for example, an external electric signal input, but can also be switched by a mechanical operation (input) such as advancing / retreating operation or rotating operation of the member. is there.

  In any case, the switching can be linked with the brake operation so that the regeneration can be performed only at the time of braking. At this time, the input from the outside can be transmitted by the switching clutch control mechanism that operates in conjunction with the brake operation. As a configuration of the switching clutch control mechanism unit, for example, the switching can be performed by utilizing the advance / retreat operation of a wire or the like interlocking with the brake operation and the rotation operation (input) of the members configuring the link mechanism.

  Furthermore, a configuration is adopted in which the switching clutch is switched based on a plurality of elements (the presence / absence of a brake operation, the number of revolutions, and the numerical value of the pedal torque) when the plurality of elements satisfy a predetermined requirement. be able to. By using a plurality of elements as a reference for switching, it becomes possible to obtain more comfortable traveling.

Further, in each of these configurations, the input means is provided on one end side of the axle, the drive motor is provided on the other end side of the axle, and the speed change mechanism portion and the speed reduction mechanism portion are provided on the input means and the drive side. A configuration provided between the motor and the motor can be employed.
If the speed change mechanism and the speed reduction mechanism are provided between the input means such as a sprocket on one end of the axle and the drive motor on the other end, the planetary carrier for the transmission and the planet carrier for the speed reducer are close to each other. Therefore, the structure for sharing the carrier can be further simplified. The drive motor is completely fixed to the axle that is supported on both ends of the bicycle, thereby ensuring high rigidity of the entire hub unit.

  Furthermore, a bicycle hub unit having these configurations can be incorporated, and an auxiliary force can be applied to the human power drive system by an electric motor, and an electric auxiliary bicycle or electric motorcycle equipped with a regeneration mechanism can be obtained.

  According to the present invention, an output member of the transmission mechanism unit and an output member of the reduction mechanism unit are commonly used in a configuration in which three mechanisms of the transmission mechanism unit, the reduction mechanism unit, and the drive motor are provided in parallel along the axis of the axle. By using these members, or members coupled so as to be integrally rotatable with each other, a structure that is compact and inexpensive in the axle direction can be obtained.

  In addition, by providing a separate output transmission member between the output member and the hub case that rotates integrally with the drive wheel, the output member can be reduced in size, and its manufacture can be simplified. The degree of freedom can be increased.

  Further, since the axle is a single member that is fixed to both ends of the bicycle frame, the axle is fixed to the frame with both ends supported, so that the rigidity of the entire rear hub unit is increased. For this reason, the intensity | strength with respect to a bending load can be improved.

A longitudinal sectional view showing an embodiment of the present invention (A) is AA sectional drawing of FIG. 1, (b) is BB sectional drawing of FIG. 1, (c) is CC sectional drawing of FIG. 1 is an enlarged view of the main part of FIG. Longitudinal sectional view showing the first gear of the same embodiment (A) is AA sectional drawing of FIG. 4, (b) is BB sectional drawing of FIG. 4, (c) is CC sectional drawing of FIG. Longitudinal sectional view showing the second gear stage of the same embodiment (A) is AA sectional drawing of FIG. 6, (b) is BB sectional drawing of FIG. 6, (c) is CC sectional drawing of FIG. Longitudinal sectional view showing the third gear stage of the same embodiment (A) is AA sectional drawing of FIG. 8, (b) is BB sectional drawing of FIG. 8, (c) is CC sectional drawing of FIG. The principal part expanded sectional view which shows the coupling | bonding state with the planetary carrier for transmissions, an output transmission member, and a hub case The principal part expanded sectional view which shows the modification of FIG. The principal part expanded sectional view which shows the further modification of FIG. Overall view of a power-assisted bicycle or electric motorcycle

Embodiments of the present invention will be described with reference to the drawings. The battery-assisted bicycle of this embodiment is a battery-assisted bicycle of the rear hub motor type in which a drive motor 18 is provided inside a hub 10 (hereinafter referred to as “rear hub 10”) as a rear wheel. FIG. 13 shows an overall view of the battery-assisted bicycle.
Note that the battery-assisted bicycle and the electric motorcycle are set so that the assisting ratio of the driving force by the driving motor with respect to the driving force by human power is different, and the main structure of the driving force transmission mechanism is the same. Therefore, in the following embodiments, the configuration of the present invention that can be applied to both the battery-assisted bicycle and the electric motorcycle will be described by collectively referring to the battery-assisted bicycle and the electric motorcycle as the battery-assisted bicycle.

  In this battery-assisted bicycle, when driving, that is, when a pedaling force transmitted from the crankshaft through the pedal 3 is input, the sprocket 9 of the rear wheel 2 that is a driving wheel (hereinafter referred to as “rear sprocket 9”). A driving force can be transmitted to the rear wheel 2 through a power transmission element 4 such as a chain connecting the two and the transmission mechanism 30 (see FIGS. 13 and 1). The rear sprocket 9 functions as input means for driving force by human power to the rear wheel 2.

  Note that the rear hub 10 is provided with a shift control mechanism unit 35 that switches the gear position of the transmission mechanism unit 30. The shift control mechanism 35 is manually or electrically input from a shift change switch attached to the outside of the rear hub 10, for example, the handle 5 or the frame 6, and the shift stage can be switched by the input.

  Further, the driving force generated by the output of the driving motor 18 as an auxiliary force is transmitted to the hub case 11 via the speed reduction mechanism 40 in the rear hub 10 and can be transmitted to the rear wheel 2.

  In addition, when the bicycle is traveling forward with inertia, the reverse input from the rear wheel 2 is transmitted to the drive motor 18 via the speed reduction mechanism 40 (in the case of reverse input, the speed is increased), and the rear wheel 2 A regenerative mechanism is provided for reducing the regenerative electric power generated by the reverse input from the secondary battery 7 to the secondary battery 7 attached to the frame 6 or the like outside the rear hub 10.

As shown in FIG. 1, the rear hub 10 includes a speed change mechanism 30, a speed reduction mechanism 40, and a drive motor 18 from one end of the rear sprocket 9 in a hub case 11 provided coaxially with the axle 15 of the rear wheel 2. In order. The axle 15 is composed of a single shaft, and both ends thereof are fixed to the frame 6 of the battery-assisted bicycle, and are in a so-called both-end fixed state.
The drive motor 18 is fixed to the axle 15 by screws or the like without any degree of freedom. The axle 15 is inserted through the central portion of the motor shaft 18 a of the drive motor 18, and the motor shaft 18 a rotates around the axle 15.

(Transmission mechanism 30)
The transmission mechanism unit 30 is constituted by a planetary gear mechanism that can change gears in three stages including direct connection and two-stage reduction. The transmission mechanism 30 includes a transmission sun gear 30a provided on the outer periphery of the axle 15 via a transmission first one-way clutch 30e. In this embodiment, the transmission sun gear 30a includes two sun gears, that is, a first sun gear 30a-1 and a second sun gear 30a-2. The first sun gear 30a-1 and the second sun gear 30a-2 are respectively connected to the outer periphery of the axle 15 via the first clutch portion 30e-1 and the second clutch portion 30e-2 of the first one-way clutch 30e for transmission. It is connected to the.

  The first clutch portion 30e-1 and the second clutch portion 30e-2 are swingably provided on a shift clutch holding portion 34 that is completely fixed (fixed immovably) on the outer periphery of the axle 15, respectively. In this embodiment, the structure in which the axle 15 and the transmission clutch holding portion 34 are fixed so as not to rotate is realized by press-fitting the axle 15 having a hexagonal cross section into a hole provided in the transmission clutch holding portion 34. . Further, the transmission clutch holding portion 34 is fixed in the axial direction of the axle 15 using a retaining ring or the like.

  The transmission mechanism 30 includes a transmission planetary gear 30b having two gear portions that mesh with the first sun gear 30a-1 and the second sun gear 30a-2, and the transmission planetary gear 30b as a planet carrier. And a planetary carrier 30c for transmission that is held via a shaft 30i. The two gear portions of the planetary gear 30b for transmission are set so that their outer diameters are different from each other and the number of teeth is different.

  Furthermore, the speed change mechanism unit 30 includes a driving body 32 that rotates integrally with the rear sprocket 9 and transmits a driving force from the rear sprocket 9. An auxiliary drive body 33 having an outer ring gear 30d for transmission that meshes with the gear portion having the smaller number of teeth of the planetary gear 30b for transmission is connected to the drive body 32 so as to rotate integrally. The transmission outer ring gear 30d may be meshed with the gear portion having the larger number of teeth of the transmission planetary gear 30b.

  Further, the transmission planetary carrier 30c and the hub case 11 are coupled via an output transmission member 50 so as to be able to transmit torque. By providing a separate output transmission member 50 between the planetary carrier 30c for transmission and the hub case 11, the outer diameter of the planetary carrier 30c for transmission is kept small, and the planetary carrier 30c for transmission is reduced. Simplifies the production process.

Further, by interposing the output transmission member 50, a portion where the load of the output member on the hub case 11 acts can be formed in the output transmission member 50. For this reason, the freedom degree in the design of the planetary carrier 30c for transmission is increased, and the strength of the coupling portion with the hub case 11 can be improved by increasing the size of the separate output transmission member 50 in the axial direction. .
In this embodiment, as shown in FIGS. 3 and 10, the transmission planet carrier 30c includes a first pocket portion (concave portion) 30p for holding the transmission planetary gear 30b and a planetary gear 40b for reduction gear. Since the second pocket portion 30q that holds the second pocket portion 30q is provided, the degree of freedom in designing the pocket portions 30p and 30q is also increased.

  In this embodiment, as shown in FIG. 10, the coupling portion 52 between the output transmission member 50 and the hub case 11 has its output transmission so that the hub case pin 52a press-fitted into the inner diameter surface 52b of the hub case 11 corresponds thereto. The output transmission member 50 is rotationally fixed inside the hub case 11 by entering into a groove 52c provided on the outer diameter side of the member 50. As a result, the load at the time of driving force transmission acts on the output transmission member 50 and does not directly act on the hub case 11, so that the hub case 11 can be made of an aluminum material having a relatively low strength. For this reason, it contributes to the weight reduction of an apparatus.

In this embodiment, serration coupling is adopted as the structure of the coupling portion 51 between the transmission planet carrier 30c and the output transmission member 50. The serration coupling is provided on the outer surface of the planetary carrier 30c for transmission, and is provided on the inner surface of the output transmission member 50 and the unevenness 51b in which ridges and grooves extending in the axial direction are alternately arranged along the circumferential direction. Similarly, the protrusions and recesses extending in the axial direction are engaged with the concave and convex portions 51a alternately arranged along the circumferential direction, so that both are coupled to rotate integrally around the axis.
The torsion angle of this serration coupling, that is, the direction in which the protrusions and the grooves of the serrations that mesh with each other extend is made to have an angle with respect to the axial direction (involute serration, etc.), thereby reducing backlash. Thus, reliable torque transmission is possible.

  The driving body 32 and the planetary carrier 30c for transmission are connected via a second one-way clutch 31 for transmission.

In this embodiment, the driving body 32 and the auxiliary driving body 33 (transmission outer ring gear 30d) are separate members, and the driving body 32 and the auxiliary driving body 33, which are separate members, rotate together via a shaft 32a. Is held by possible bonds. Thus, if the driving body 32 and the auxiliary driving body 33 are formed as separate members, the driving body 32 that does not require relatively strong strength is an aluminum material, and an outer ring gear for a transmission that requires a hardened layer by heat treatment. The auxiliary drive body 33 provided with 30d and the clutch cam surface can be made of a different material such as a steel material, and the weight can be reduced.
Moreover, in this embodiment, the drive body 32 and the auxiliary drive body 33 are floatingly supported in a radial direction (a state in which the drive body 32 is supported with a degree of freedom in radial movement) so that the arrangement of the gears can achieve a load balance. By being arranged at the position, the entire load balance is easily obtained. Note that the driving body 32 and the auxiliary driving body 33 may be formed as an integral member.

Further, it is attached to the end face of the drive motor 18 and the ring member 17 that closes the end face of the hub case 11, between the drive body 32 and the shift control mechanism 35 provided on the outer periphery of the axle 15, between the drive body 32 and the hub case 11. Between the lid 16, bearings 12, 13, and 14 are provided, respectively. The bearings 12, 13, and 14 support the respective members so as to be relatively rotatable.
A bearing portion 26 is also provided between the motor housing 18b that holds the drive motor 18 and the outer ring gear 40d for reduction gear. The motor housing 18b and the reduction gear outer ring gear 40d are supported by the bearing portion 26 so as to be relatively rotatable. In the bearing portion 26, a plurality of rollers 26a held by a cage 26b are arranged along the circumferential direction.

  By operating the shift control mechanism unit 35, the second clutch unit 30e-2 and the second one-way clutch 31 for transmission can be switched. By the switching, the second sun gear 30a-2 is switched with respect to the axle 15, and the driving body 32 is switched with respect to the transmission planet carrier 30c between a state in which the second sun gear 30a-2 can rotate in one direction around the axis and a state in which the driving body 32 cannot rotate.

  FIGS. 1 and 2 show the state of each clutch at the third gear position (at the third speed). As shown in FIGS. 2A, 2B, and 2C, at the third speed, all the clutches are engaged with the clutch cam surface. That is, at the third speed, there is no restriction for laying down each clutch, and all the above-described three clutches are in mesh with the clutch cam surface.

  In this embodiment, a ratchet clutch that is relatively inexpensive as compared with other clutch mechanisms is used for the first clutch portion 30e-1, the second clutch portion 30e-2, and the second one-way clutch 31 for transmission. Adopted. However, the types of these clutches are not limited, and other different clutches such as a roller clutch and a sprag clutch having a high backlash effect (rattle prevention effect) may be used.

  As shown in FIG. 2A, the first clutch portion 30e-1 of the transmission first one-way clutch 30e includes a first first-way clutch pawl 30f (first clutch) that can swing on the outer periphery of the axle 15. Claw portion 30f-1). The first clutch pawl portion 30f-1 is a first one-way clutch cam surface 30g for transmission (first cam surface portion 30g-1) provided on the inner peripheral surface of the first sun gear 30a-1 by an elastic member (not shown). It is urged in the direction of meshing. Since the first clutch pawl portion 30f-1 meshes with the first cam surface portion 30g-1, the first sun gear 30a-1 can be made non-rotatable only with respect to the axle 15 in one direction around the axis. The first sun gear 30a-1 is always rotatable about the axle 15 (idling state) with respect to rotation in the other direction around the axis.

  Similarly, as shown in FIG. 2 (b), the second clutch portion 30e-2 of the first one-way clutch for transmission 30e has a first one-way clutch pawl 30f for transmission that can swing on the outer periphery of the axle 15. 2nd clutch nail | claw part 30f-2) is provided. The second clutch pawl 30f-2 is a first one-way clutch cam surface 30g for transmission (second cam surface 30g-2) provided on the inner peripheral surface of the second sun gear 30a-2 by an elastic member (not shown). It is urged in the direction of meshing. Since the second clutch pawl portion 30f-2 meshes with the second cam surface portion 30g-2, the second sun gear 30a-2 can be made non-rotatable only with respect to the axle 15 in one direction around the axis. Note that the second sun gear 30a-2 is always rotatable about the axle 15 (idle state) with respect to rotation in the other direction around the axis.

The second clutch pawl portion 30f-2 of the second clutch portion 30e-2 can be switched ON / OFF by the rotation operation of the clutch switching member 37 provided in the transmission control mechanism portion 35. That is, if the switching state is turned OFF, the second clutch pawl portion 30f-2 of the second clutch portion 30e-2 is in a state where it cannot be engaged with the second cam surface portion 30g-2 (a state where it cannot be engaged). The second sun gear 30 a-2 can be rotated in both directions with respect to the rotation about the axis with respect to the axle 15.
Further, if the switching state is turned ON, the second clutch pawl portion 30f-2 of the second clutch portion 30e-2 is in a state (engageable state) that can be engaged with the second cam surface portion 30g-2, The second sun gear 30a-2 is not rotatable with respect to the axle 15 with respect to rotation in one direction around the axis.
Thus, the second sun gear 30 a-2 can be switched between rotation and non-rotation with respect to rotation in one direction around the axis with respect to the axle 15.

The second one-way clutch 31 for transmission is provided so that the second one-way clutch pawl 31f for transmission can swing around a planet carrier shaft 30i that supports the planetary gear 30b for transmission on the planet carrier 30c for transmission. It has been.
The transmission second one-way clutch pawl 31f is disposed on the planetary carrier 30c for transmission toward the outer periphery, and is provided on the inner peripheral surface of the drive body 32 (auxiliary drive body 33) by an elastic member (not shown). The second one-way clutch cam surface 31g for the machine is biased in the direction of meshing. Thus, it is desirable to provide the second one-way clutch cam surface 31g for transmission on the inner peripheral surface of the drive body 32 (auxiliary drive body 33) rather than the outer peripheral surface of the planetary carrier 30c for transmission.

  The second one-way clutch pawl 31f for transmission meshes with the second one-way clutch cam surface 31g for transmission, so that the planetary carrier 30c for transmission is unidirectional around the axis with respect to the drive body 32 (auxiliary drive body 33). It can be made non-rotatable only with respect to rotation. It should be noted that the transmission planet carrier 30c is always rotatable to the drive body 32 (auxiliary drive body 33) (idling state) with respect to rotation in the other direction around the axis.

  In this embodiment, the second one-way clutch pawl 31f for transmission is configured to be attached to the planet carrier shaft 30i in order to improve its assemblability, but this is attached to another shaft provided on the planet carrier 30c for transmission. It is also possible to install.

As described above, when another shaft is used to support the transmission second one-way clutch pawl 31f, the transmission second one-way clutch pawl 31f includes the number of transmission planetary gears 30b (3 in this embodiment). For example, it is possible to set the number to four or more.
However, the number of the second one-way clutch pawls 31f for the transmission is two or one, so that the device can be simplified. When considering the load balance, two or more are suitable at equal intervals.

(Transmission control mechanism 35)
FIG. 3 shows a detailed view of the shift control mechanism unit 35. The shift control mechanism 35 includes a clutch switching member 39, a clutch switching control member 37, a clutch switching guide member 38, and a shift switching rod (shift operating unit) 36 that transmits an external signal into the rear hub unit. The end portion 36b of the shift switching rod 36 is pushed in by a signal input manually or electrically from a hand switch or the like.

  A shift guide groove 35 b is provided on the axle 15. The speed change guide groove 35b has a shape twisted at a certain angle with respect to the axial direction. By pushing the speed change switch rod 36, the pin 35c held in the speed change guide groove 35b moves in the axial direction of the axle 15 while rotating around the axis of the axle 15. By the operation of the pin 35c, the clutch switching control member 37 rotates about the axis of the axle 15 by the same angle. The pin 35c receives a reaction force in the direction opposite to the pushing direction by the elastic force of the elastic member 35d disposed in the shaft hole 15a inside the axle 15. For this reason, the pin 35c is stably disposed between the shift switching rod 36 and the elastic member 35d.

  Further, by the rotation operation of the clutch switching control member 37, the first one-way clutch switching portion 37a for transmission provided in the clutch switching control member 37 becomes the second clutch portion 30e-2 of the first one-way clutch 30e for transmission. , The state is switched between the state in contact with the second clutch pawl portion 30f-2 and the state in which it is separated. By the switching, the swing of the second clutch pawl portion 30f-2 is controlled, and the second sun gear 30a-2 is in a state in which the second sun gear 30a-2 can rotate relative to the rotation of the axle 15 in one direction or cannot rotate. Switch to

  Further, the clutch switching member 39 is pressed by the transmission second one-way clutch switching portion 37b having an inclined surface provided in the clutch switching control member 37, and is movable along the axial direction of the axle 15. The clutch switching member 39 is switched between a state in which the second one-way clutch pawl 31f of the transmission is in contact with the second one-way clutch pawl 31f and a state in which the second one-way clutch 31 is separated. By the switching, the swing of the second one-way clutch pawl 31f for transmission is controlled, and the outer ring gear 30d (drive body 32, auxiliary drive body 33) for transmission and the planet carrier 30c for transmission are It switches to a state in which relative rotation is possible or relative rotation is impossible with respect to rotation in one direction.

The portions where the first one-way clutch switching portion 37a for transmission and the clutch switching member 39 abut on each clutch pawl are tapered surfaces that gradually approach the inner diameter side in one axial direction. From the state where each clutch pawl is engaged with and engaged with the cam surface, the force for releasing the engagement can be increased.
Further, the clutch switching member 39 includes an elastic member 35e between the clutch switching guide member 38 provided on the outer periphery of the axle 15 or a separate member. Is released, the transmission second one-way clutch switching portion 37b is automatically disengaged from the position of the transmission second one-way clutch pawl 31f.

(Deceleration mechanism 40)
Next, the speed reduction mechanism unit 40 will be described. The reduction mechanism unit 40 is configured by a planetary gear mechanism, and a reduction gear sun gear 40a provided on the outer periphery of the motor shaft 18a of the drive motor 18, and a reduction gear planetary gear that meshes with the reduction gear sun gear 40a. 40b, and a reduction gear outer ring gear 40d that meshes with the reduction gear planetary gear 40b.

  The motor shaft 18a and the reduction gear sun gear 40a are the same member, or the reduction gear sun gear 40a is held by a member that rotates integrally with the motor shaft 18a. Moreover, the planetary gear 40b for reduction gears implement | achieves a high reduction ratio by providing the two-stage gear part from which the number of teeth differs.

  That is, in the speed reduction mechanism section 40, the first outer diameter gear section 40e provided in the reduction gear planetary gear 40b meshes with the reduction gear sun gear 40a, and the first outer diameter gear section 40e provided in the reduction gear planetary gear 40b. The second outer diameter gear portion 40f having a smaller diameter with fewer teeth meshes with the transmission outer ring gear 40d.

Further, the planetary gear 40b for reduction gear and the planet carrier 30c for transmission are connected via a planet carrier shaft 40i. That is, the carrier holding the reduction gear planetary gear 40b is the transmission planetary carrier 30c, and the transmission planetary gear 30b and the reduction gear planetary gear 40b are held by a common carrier.
Further, as described above, the transmission planet carrier 30c and the hub case 11 can transmit torque from the outer periphery of the transmission planet carrier 30c to the inner diameter portion of the hub case 11 via the output transmission member 50. It is joined to.

That is, the reduction planetary gear 40b is held by the transmission planetary carrier 30c, so that the transmission planetary carrier 30c transmits the output in both the driving force by human power and the driving force by the driving motor 18. It functions as a common output member to the hub case 11 via the member 50. That is, the speed change mechanism 30 uses the rear sprocket 9 and the driving body 32 as input members for driving force by human power, and the planetary carrier for transmission 30c as an output member to the hub case 11 via the output transmission member 50. Further, the speed reduction mechanism section 40 uses the reduction gear sun gear 40 a as an input member for driving force from the driving motor 18, and uses the transmission planetary carrier 30 c as an output member to the hub case 11 via the output transmission member 50. .
In this way, a compact structure is realized by holding the transmission planetary gear 30b and the reduction planetary gear 40b with a common carrier. Further, unlike the prior art, it is not necessary to arrange the speed change mechanism 30 and the speed reduction mechanism 40 by completely separate routes, and a compact structure in the axle direction can be achieved. Further, since the axial dimension of the hub can be shortened, the assembly can be further simplified as compared with the case where the speed change mechanism 30 and the speed reduction mechanism 40 are independently engaged with the hub case 11.

In addition, a switching clutch 20 is provided that can switch between a reduction gear outer ring gear 40d that meshes with the reduction gear planetary gear 40b and a motor housing 18b that holds the drive motor 18 so as to be relatively rotatable or not relatively rotatable.
The reduction gear outer ring gear 40d is rotationally fixed (non-rotatably fixed) to the motor housing 18b by the switching clutch 20, so that the driving force from the driving motor 18 is output from the reduction gear sun gear 40a as an output member. The transmission planetary carrier 30 c is decelerated and output, and the driving force is transmitted to the rear wheel 2 through the hub case 11.

  The rotation support of the reduction gear outer ring gear 40d to the motor housing 18b is performed by the bearing 26, and the two-way clutch provided between the motor housing 18b and the reduction gear outer ring gear 40c arranged in parallel with the bearing 26. The rotation fixed state can be set by engagement of a switching clutch 20 (hereinafter referred to as “two-way clutch 20”). The motor housing 18b is held together with the driving motor 18 so as not to rotate relative to the bicycle frame 6 or the axle 15.

(Two-way clutch 20)
In this embodiment, the two-way clutch 20 employs a roller clutch using a roller as the engagement element 23. In the two-way clutch 20, when the motor is driven (when the driving force from the driving motor 18 acts and the battery-assisted bicycle moves forward), the retainer 24 that holds the engagement element 23 is always fixed by an elastic member (not shown). A load is applied in the direction in which the two-way clutch 20 is engaged. For this reason, the reduction gear outer ring gear 40d is rotationally fixed to the motor housing 18b.
Further, when the motor is not driven (when the battery-assisted bicycle moves forward only by driving force by human power), the cage 24 is rotated by an elastic member toward the direction of rotation together with the outer ring gear 40d for reduction gear. Therefore, the reduction gear outer ring gear 40d rotates in the direction of idling with respect to the motor housing 18b, that is, in the direction opposite to the direction in which the driving force from the driving motor 18 acts. For this reason, torque is not transmitted to the motor shaft 18a, that is, the drag torque of the drive motor 18 can be cut off.

  When the battery-assisted bicycle travels inertially on a downhill or the like and is reversely input from the rear wheel 2 (hub case 11) and regenerative charging is performed by the rotational force, the two-way clutch 20 is input from the switching clutch control mechanism unit 25. Switching is made possible by (external input signal). As a result, the reverse input from the hub case 11 is transmitted to the drive motor 18 via the speed reduction mechanism 40 and can be regenerated.

  The two-way clutch 20 can be switched between an engageable state and an unengageable state by a manual or electric external signal (input) transmitted to the switching clutch control mechanism unit 25. The external input is transmitted to the two-way clutch 20 by the switching clutch control mechanism 25 in conjunction with the brake operation.

  In this embodiment, as shown in FIG. 1, as the switching clutch control mechanism unit 25, an advancing / retreating operation of a wire or the like interlocking with a brake operation is input to the input mechanism 25a, and the input mechanism 25a is actuated by the input by the input member 25b. Is pushed against the urging force of the elastic member 25c toward the outer diameter side, and the cage 24 is loaded with an external force in the rotational direction or resistance against the rotation. When the load of the external force or resistance is equal to or greater than the biasing force of the elastic member of the cage 24, the cage 24 is delayed from the rotation of the outer ring gear 40d for the speed reducer, and the two-way clutch 20 can be switched. .

In addition, by setting the same number of planetary gears 30b and 40b in the speed change mechanism 30 and the speed reduction mechanism 40, the inside of the speed change mechanism 30 by the driving force from the driving motor 18 and the driving force of human power. The driving force can be balanced. Further, in order to utilize a limited space, it is desirable to set the number of both planetary gears 30b and 40b by three.

  The operation of each member will be described with reference to FIG.

4 and 5 show the arrangement of the rear hub unit at the first shift (at the first speed). In this embodiment, the rear sprocket 9 is attached to the drive body 32 of the speed change mechanism unit 30, and the driving force by human power from the pedal 3 is transmitted to the drive body 32.

In the first shift, the first clutch portion 30e-1 of the first one-way clutch for transmission 30e is in a state that can be engaged with the driving force by the first clutch pawl portion 30f-1, One end of the second clutch pawl 30e-2 is restrained by the first one-way clutch switching portion 37a for transmission of the clutch switching control member 37 and cannot be engaged.
Further, the second one-way clutch 31 for transmission is connected at its one end by a clutch switching member 39 in which the second one-way clutch pawl 31f for transmission operates through the second one-way clutch switching portion 37b for transmission of the clutch switching control member 37. It is restrained and cannot be engaged.

  For this reason, the driving force by human power is input to the planetary gear 30b for transmission through the driving body 32 and the auxiliary driving body 33. At this time, the first sun gear 30a-1 is driven by the first clutch portion 30e-1. Since it is engaged in the direction, the driving force is transmitted to the hub case 11 via the transmission planetary carrier 30c.

In this state, the driving force from the rear sprocket 9 is a speed ratio, where a1 is the number of teeth of the first sun gear 30a-1 and d1 is the number of teeth of the outer ring gear 30d for transmission.
d1 / (a1 + d1)
Is transmitted to the hub case 11.

  FIGS. 6 and 7 show the arrangement of the rear hub unit at the second gear position (at the second speed). Similar to the first gear stage, the rear sprocket 9 is attached to the drive body 32 of the transmission mechanism unit 30, and the driving force by human power from the pedal 3 is transmitted to the drive body 32.

When the speed change rod 36 is pushed, the pin 35c is also pushed into the hub, and the pin 35c and the clutch switching control member 37 rotate around the axis. In the second gear, the first clutch portion 30e-1 of the transmission first one-way clutch 30e is in a state in which the first clutch pawl portion 30f-1 can be engaged, as in the first speed. Further, the second clutch portion 30e-2 has the second clutch pawl portion 30f-2 released from the restriction of the one end by the first one-way clutch switching portion 37a for transmission due to the rotational movement of the clutch switching control member 37. It is possible to match.
In addition, the second one-way clutch 31 for transmission is in a state where one end of the second one-way clutch pawl 31f for transmission is restricted by the clutch switching control member 39 and cannot be engaged. At this time, the first sun gear 30a-1 is in a state in which the first clutch pawl 30f-1 can be engaged in one direction around the axis. Since it rotates in the reverse direction, it can idle. Therefore, only the second sun gear 30a-2 is engaged in the driving force direction.

  Therefore, the driving force by human power is input to the planetary gear for transmission 30b through the driving body 32 and the auxiliary driving body 33, and the second sun gear 30a-2 is engaged in the driving force direction by the second clutch portion 30e-2. Therefore, the driving force is transmitted to the hub case 11 via the transmission planetary carrier 30c.

At this time, the transmission planetary gear 30b has two stages of gear portions (gears) having different numbers of teeth, and the gear portion on the side having the smaller number of teeth of the transmission planetary gear 30b includes the outer ring gear 30d for transmission, The gear portion with the larger number of teeth meshes with the second sun gear 30a-2.
In this state, the driving force from the rear sprocket 9 is such that the number of teeth of the second sun gear 30a-2 is a2, the number of teeth of the outer ring gear 30d for transmission is d1, and the number of teeth of the planetary gear 30b for transmission is smaller. When the number of teeth of the gear part is b1, and the number of teeth of the gear part on the side with the larger number of teeth is b2,
(B2 × d1) / [(a2 × b1) + (b2 × d1)]
Is transmitted to the hub case 11.

  8 and 9 show the arrangement of the rear hub unit at the third gear position (at the third speed). The rear sprocket 9 is attached to the drive body 32 of the speed change mechanism 30 as in the first and second speed changes, and the driving force generated by human power from the pedal 3 is transmitted to the drive body 32.

The pin 35c is also pushed into the hub when the speed change rod 36 is pushed to the farthest side, and the pin 35c and the clutch switching control member 37 further rotate around the axis. In the third speed change step, the first clutch portion 30e-1 of the first one-way clutch for transmission 30e has the first clutch pawl portion 30f-1 in the driving direction of the first sun gear 30a-1 at the first speed. It can be engaged only with respect to the rotation. Further, the second clutch portion 30e-2 is engaged with the second clutch pawl portion 30f-2 by releasing the restriction at one end by the first one-way clutch switching portion 37a for transmission by the rotational movement of the clutch switching control member 37. It is possible.
Further, the transmission second one-way clutch 31 is configured such that the transmission second one-way clutch pawl 31 f is rotated by the clutch switching control member 37, and the transmission second one-way clutch switching unit 37 b is the shaft of the clutch switching member 39. Release the direction movement constraint. As a result of this release, the clutch switching member 39 is moved to the left in FIG. 8 by the elastic force of the elastic member 35e, so that the restriction at one end of the second one-way clutch pawl 31f for transmission is released, and the second one-way for transmission is released. The clutch 31 can be engaged.

  At this time, the first sun gear 30a-1 is in a state where the first clutch pawl portion 30f-1 can be engaged in one direction around the axis. Can rotate idly because it rotates in the reverse direction, and the second sun gear 30a-2 is in a state in which the second clutch pawl 30f-2 can be engaged in one direction around the axis. When this acts, it rotates idly because it rotates in the direction opposite to the engageable direction. Therefore, the outer ring gear 30d for transmission and the planet carrier 30c for transmission cannot be rotated relative to the driving force direction.

  For this reason, the driving force is transmitted to the planetary carrier 30c for transmission from the driving body 32 and the outer ring gear 30d for transmission via the second one-way clutch 31 for transmission, and is transmitted to the hub case 11 in a directly connected state. In this highest speed gear stage, since no gear is used for torque transmission, the durability of the hub is remarkably improved.

  In addition, when the motor is driven, when the driving force from the driving motor 18 is applied regardless of the gear position, the motor shaft 18a is held integrally or rotatably with the reduction gear sun gear 40a. ing. A two-way clutch 20 is disposed between the outer ring gear for reduction gear 40d and the motor housing 18b. Further, the two-way clutch 20 applies a load to the roller 23 as an engaging element in a direction to engage with a forward cam surface (not shown) on one side in the circumferential direction with respect to the driving force by the driving motor 18. Yes. This addition is given from an elastic member (not shown) via a cage 24. For this reason, the two-way clutch 20 can always transmit power by the driving force of the driving motor 18.

  For this reason, the driving force from the drive motor 18 is transmitted to the planetary carrier 30c for transmission via the planetary gear 40b for reduction gear, and further transmitted to the hub case 11 from the planetary carrier 30c for transmission through the output transmission member 50. Is done.

  Further, the reduction gear planetary gear 40b has two stages of gear portions (gears) having different numbers of teeth, and the gear portion on the side having the smaller number of teeth of the reduction gear planetary gear 40b (the second outer diameter gear portion 40f) is provided. The reduction gear outer ring gear 40d and the gear portion having the larger number of teeth (the first outer diameter gear portion 40e) mesh with the reduction gear sun gear 40a. As described above, the reduction gear planetary gear 40b has two stages, so that a high reduction ratio can be realized.

In this state, the driving force from the drive motor 18 is such that the number of teeth of the reduction gear sun gear 40a is a3, the number of teeth of the reduction gear outer ring gear 40d is d2, and the number of teeth of the reduction gear planetary gear 40b is smaller. If the number of teeth of the gear part is b3 and the number of teeth of the gear part on the side with the larger number of teeth is b4, the speed ratio with respect to the motor rotational speed,
(A3 × b3) / [(a3 × b3) + (b4 × d2)]
Is transmitted to the hub case 11.

  Further, when the motor is not driven, for example, when the speed range set to perform the motor assist is exceeded, or when the driving force from the driving motor 18 is not loaded due to a reason such as battery exhaustion, the hub case Torque is transmitted from 11 to the drive motor 18 via the planetary gear 40b for reduction gear. This torque is a torque in the direction opposite to that when the motor is driven. At this time, a rotational load is applied to the cage 24 of the two-way clutch 20 by an elastic member in a direction in which the cage 24 rotates together with the reduction gear outer ring gear 40d. For this reason, the reduction gear outer ring gear 40d rotates in the idling direction with respect to the motor housing 18b, and torque is not transmitted to the motor shaft 18a, that is, the drag torque of the motor can be cut off.

  Further, when a reverse input is made from the rear wheel 2 (hub case 11) on a downhill or the like and regenerative charging is performed by the rotational force, the two-way clutch 20 is switched to the two-way by an external input signal through the switching clutch control mechanism unit 25. Resistance is applied to the retainer 24 of the clutch 20, and the retainer 24 and the engagement element (roller) 23 are moved in a direction to engage with the regeneration side cam surface in a rotation direction different from that during forward movement to switch to an engageable state. As a result, the reverse input from the hub case 11 is input from the transmission planetary carrier 30c and transmitted to the reduction gear sun gear 40a (motor shaft 18a) via the reduction gear mechanism 40, to the outside of the rear hub unit. Rechargeable charging is possible for the provided secondary battery 7.

  In this embodiment, a roller clutch is employed as the two-way clutch 20, but a sprag clutch or a clutch provided with a ratchet mechanism may be employed instead.

In this embodiment, the number of stages of the planetary gear for transmission 30b is two, but the number of stages of the planetary gear for transmission 30b may be three or four or more.
In consideration of making the radius and thickness of the planetary gear as small as possible, it is most desirable that the two planetary gear mechanisms are constituted by three planetary gears. Further, the load balance can be achieved by making the number of planetary gears the same.

  Further, in these embodiments, in the first one-way clutch 30e for transmission and the second one-way clutch 31 composed of a ratchet clutch, the engagement of each clutch pawl of the ratchet clutch with the clutch cam surface is rotated. Although the clutch switching control member 37 that moves and the clutch switching member 39 that moves in the axial direction in conjunction with the clutch switching member 39 are switched between the engageable state and the disengageable state, the axle 15 and the transmission are used. Other configurations may be adopted as means for switching the sun gear 30a, the transmission outer ring gear 30d (driving body 32), and the transmission planetary carrier 30c between relative rotation and non-rotation.

  In this embodiment, the first one-way clutch for transmission 30e and the second one-way clutch for transmission 31 each employ a ratchet clutch. However, the one-way clutch having other configurations such as a roller clutch and a sprag clutch. May be adopted.

In this embodiment, as shown in FIG. 10, serration coupling is adopted as the structure of the coupling portion 51 between the transmission planet carrier 30 c and the output transmission member 50. Further, as a structure of the coupling portion 52 between the output transmission member 50 and the hub case 11, a hub case pin 52 a that is press-fitted into the inner diameter surface 52 b of the hub case 11 is in a groove portion 52 c provided on the outer diameter side of the output transmission member 50. The output transmission member 50 is press-fitted and fixed inside the hub case 11 by entering.

  Instead of the structure of the coupling portions 51 and 52, for example, a modification shown in FIG. 11 can be adopted.

  In this modification, a so-called polygonal coupling is adopted as the structure of the coupling portion 51 between the transmission planet carrier 30c and the output transmission member 50. For example, the polygonal coupling is such that a hole having a regular octagonal cross section is provided on the inner diameter side of the output transmission member 50, and the outer diameter shape of the planetary carrier 30c for transmission is a regular octagonal cross section. A transmission planet carrier 30c having a regular octagonal cross section is fitted to the inner surface 51c, and torque can be transmitted between the inner surface 51c of the hole and the outer surface 51d of the transmission planet carrier 30c. Note that this cross-sectional shape is not limited to a regular octagonal cross section, and other regular polygonal shapes such as a regular hexagonal cross section or a polygonal shape can be employed.

  Further, by having an appropriate backlash (backlash) between the inner surface 51c of the hole and the outer surface 51d of the planetary carrier 30c for transmission, each member of the planetary gear mechanism is moved to an appropriate position. Smooth rotation that absorbs manufacturing errors of members is possible.

  11, the hub case 11 and the output transmission member 50 are fixed by a screw member 52f screwed from the outside of the hub case 11 as a structure of the coupling portion 52 between the output transmission member 50 and the hub case 11. Communication is possible. The screw member 52 f is screwed into the hole 52 e provided in the hub case 11 and the screw hole 52 d provided in the output transmission member 50. As a result, the hub case 11 can select an aluminum material having a relatively low strength, which contributes to weight reduction. Further, the shape of the output transmission member 11g can be simplified, which is advantageous in terms of manufacturing.

  Moreover, as a further modification of the coupling portions 51 and 52, for example, a modification shown in FIG. 12 can be adopted.

In the modification of FIG. 12, the planetary carrier shaft 40i that supports the reduction gear planetary gear 40b on the reduction gear mechanism 40 side is used as the structure of the coupling portion 51 of the transmission planetary carrier 30c and the output transmission member 50. The planet carrier 30c for transmission and the output transmission member 50 are fixed by the planet carrier shaft 40i to enable torque transmission.
That is, the planet carrier shaft 40i press-fitted into the inner diameter surface 51e of the output transmission member 50 enters the groove 51d provided on the outer diameter side of the transmission planet carrier 30c so as to correspond to the planet carrier shaft 40i. The member 50 is press-fitted and fixed to the outside of the planetary carrier 30c for transmission. According to this configuration, the shape of the member can be simplified, which is advantageous in manufacturing.

In the modification of FIG. 12, serration coupling is adopted as the structure of the coupling portion 52 between the output transmission member 50 and the hub case 11. The serration coupling is provided on the outer surface of the output transmission member 50, and is provided on the inner surface of the hub case 11 with projections and depressions 52g in which ridges and grooves extending in the axial direction are alternately arranged in the circumferential direction. The extending protrusions and the recessed grooves are engaged with the concave and convex portions 52h alternately arranged along the circumferential direction, so that both are coupled so as to rotate integrally around the axis.
In this serration coupling, the structure in which the protrusions of the serrations and the grooves that engage with each other extend in a torsion angle with respect to the axial direction reduces rattling and enables reliable torque transmission. .

Note that the structure of the coupling portion 51 between the planetary carrier 30c for transmission and the output transmission member 50 and the structure of the coupling portion 52 between the hub case 11 and the output transmission member 50 are the coupling portions in the above embodiments and modifications. Appropriate ones can be selected from the configurations 51 and 52 and combined.
At this time, in order to enable smooth rotation that absorbs the manufacturing error of each member, it is desirable to provide a looseness that can be moved in the radial direction in one of the coupling portions 51 and 52. Further, by configuring one of the coupling portions 51 and 52 to have a degree of freedom in the axial direction, the transmission planet carrier 30c and the output transmission member 50 absorb the manufacturing error. Moves to a balanced position, enabling smoother rotation.

1 Electric assist bicycle (electric motorcycle)
2 Drive wheels (rear wheels)
3 Pedal 4 Power transmission element (chain)
5 Handle 6 Frame 7 Secondary battery 8 Hub flange 9 Input means (rear sprocket)
10 Hub (rear hub)
11 Hub case 12, 13, 14, 18c, 26 Bearing 15 Axle 15a Shaft hole 16 Lid 17 Ring member 18 Driving motor 18a Motor shaft 18b Motor housing 19 Holding member 20 Switching clutch (two-way clutch)
21 cam surface 22 outer diameter surface 23 engagement element 24 retainer 25 switching clutch control mechanism 25a input mechanism 25b action member 25c elastic member 30 transmission mechanism 30a transmission sun gear 30a-1 first sun gear 30a-2 first Double sun gear 30b Planetary gear 30c for transmission Planetary carrier 30d for transmission Gearbox outer ring gear 30e First one-way clutch 30e-1 for transmission First clutch part 30e-2 Second clutch part 30f First one-way for transmission Clutch pawl 30f-1 First clutch pawl 30f-2 Second clutch pawl 30g Transmission first one-way clutch cam surface 30g-1 First cam surface 30g-2 Second cam surface 30i Planetary carrier shaft 30p First pocket Part (concave)
30q Second pocket (recess)
31 Second one-way clutch for transmission 31f Second one-way clutch pawl for transmission 31g Second one-way clutch cam surface for transmission 32 Driving body 32a Shaft 33 Auxiliary driving body 34 Transmission clutch holding section 35 Transmission control mechanism section 35b Transmission guide groove 35c Pin 36 Shifting switch rod (shifting operation part)
36a End 37 Clutch switching control member 37a Transmission first one-way clutch switching unit 37b Transmission second one-way clutch switching unit 38 Clutch switching guide member 39 Clutch switching member 40 Deceleration mechanism unit 40a Decelerator sun gear 40b Decelerator Planetary gear 40d Reduction gear outer ring gear 40e First outer gear portion 40f Second outer gear portion 40i Planet carrier shaft 50 Output transmission member 51, 52 Coupling portion 51a, 51b Concavity 51c Inner surface 51d Outer surface 52a Hub case pin 52b Inner diameter Surface 52c Groove 52d Screw hole 52e Hole 52f Screw member 52g, 52h Concavity and convexity

Claims (15)

A bicycle hub unit in which a transmission mechanism (30), a speed reduction mechanism (40), and a drive motor (18) are arranged in parallel in the axial direction of the axle (15) inside the hub (10).
The speed change mechanism portion (30) has a function of transmitting a driving force generated by human power input to the input means (9) to the hub case (11), and the speed reduction mechanism portion (40) is provided with the drive motor (18). ) Has a function of transmitting the driving force input from the hub case (11),
The output member of the speed change mechanism portion (30) and the output member of the speed reduction mechanism portion (40) are composed of the same member or a member coupled so as to be integrally rotatable, and the speed change mechanism portion (30) and the speed reduction mechanism are configured. A bicycle hub unit characterized in that an output transmission member (50) is provided between the output member of the portion (40) and the hub case (11) so that the output member and the hub case (11) can rotate together. . The transmission mechanism section (30) is constituted by a planetary gear mechanism having two or more shift stages, and is a transmission that meshes with at least one transmission sun gear (30a) and the transmission sun gear (30a). A planetary gear for transmission (30b) and a planetary gear for transmission (30c) that holds the planetary gear for transmission (30b), and the at least one speed change with respect to the driving force from the input means (9) A shift control mechanism (35) for shifting the mechanical sun gear (30a) to be rotatable or non-rotatable around the axle (15);
The speed reduction mechanism section (40) is constituted by a planetary gear mechanism and is rotated integrally with the motor shaft (18a) of the drive motor (18), and the speed reducer sun gear (40a). The bicycle hub unit according to claim 1, further comprising a reduction gear planetary gear (40b) meshing with (40a).   The output member to the hub case (11) of the speed change mechanism (30) is the planetary carrier (30c) for transmission, and the output member to the hub case (11) of the speed reduction mechanism (40) is the The bicycle hub unit according to claim 2, wherein the transmission planetary carrier (30c) or a member that can rotate integrally with the transmission planetary carrier (30c).   The planetary gear for transmission is held by the planetary gear for transmission (40b) by the planetary carrier for transmission (30c) which is an output member of the transmission mechanism (30) to the hub case (11). The bicycle hub unit according to claim 2 or 3, wherein (30c) is used as an output member to the hub case (11) of the speed reduction mechanism (40).   For switching which can switch between a reduction gear outer ring gear (40d) meshing with the reduction gear planetary gear (40b) and a motor housing (18b) holding the drive motor (18) so as to be relatively rotatable or not relatively rotatable. The bicycle hub unit according to any one of claims 2 to 4, further comprising a clutch (20).   The bicycle hub unit according to any one of claims 1 to 5, wherein the axle (15) is a single member that is both-side fixed to the bicycle frame (6).   The bicycle according to any one of claims 1 to 6, wherein the hub case (11) and the output transmission member (50) are coupled to each other so as to be relatively movable in the axial direction and to be integrally rotatable about the axis. Hub unit.   The bicycle according to any one of claims 1 to 7, wherein the hub case (11) and the output transmission member (50) are coupled to each other so as to be relatively movable in a radial direction and to be integrally rotatable about an axis. Hub unit.   The planetary carrier for transmission (30c) and the output transmission member (50) are coupled to each other so as to be relatively movable in the axial direction and integrally rotatable about the axis. The bicycle hub unit described in 1.   The planetary carrier for transmission (30c) and the output transmission member (50) are coupled to each other so as to be relatively movable in the radial direction and integrally rotatable about an axis. The bicycle hub unit described in 1.   The planetary carrier (30c) for transmission and the output transmission member (50) are coupled to a planet carrier shaft supporting the planetary carrier (30c) for transmission and the planetary gear (40b) for reduction gear. The bicycle hub unit according to claim 9 or 10, wherein the bicycle hub unit is performed via (40i).   The bicycle according to any one of claims 1 to 11, wherein the speed change mechanism portion (30) is a deceleration type including a direct connection state from the input means (9) to the hub case (11). Hub unit.   The speed change mechanism portion (30) is a speed reduction type including a direct connection state from the input means (9) to the hub case (11) and a speed reduction state of two or more stages. The bicycle hub unit according to any one of the above.   The input means (9) is provided on one end side of the axle (15), and the drive motor (18) is provided on the other end side of the axle (15), and the speed change mechanism portion (30) and the speed reduction mechanism portion ( The bicycle hub unit according to any one of claims 1 to 13, wherein 40) is provided between the input means (9) and the drive motor (18).   A battery-assisted bicycle or an electric motorcycle using the bicycle hub unit according to any one of claims 1 to 14.

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