JP2012136081A - Internal motorized bicycle hub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal motorized bicycle hub, which suppresses noise even when an outer ring of a bearing is loosely fitted in a rotor.SOLUTION: The internal motorized hub includes a hub shaft 15, a motor, a first bearing 66a, a second bearing 66b, a movement limiting part 68, and a pressing part 73. The motor includes a rotor 21, and a stator located on the outer circumferential side of the rotor 21. The first bearing 66a and the second bearing 66b include a first inner ring 71a and a second inner ring 72a fitted to in the hub shaft 15, a first outer ring 71b and a second outer ring 72b fitted to the rotor 21, and a first rolling element 71c and a second rolling element 72c arranged between the first outer ring 71b and the second outer ring 72b. The movement limiting part 68 limits the movement of the first inner ring 71a in a direction away from the second bearing 66b. The pressing part 73 presses the first outer ring 71b to the second bearing 66b.

Description

  The present invention relates to a bicycle hub, and more particularly to a motor-equipped bicycle hub that constitutes a hub of a bicycle wheel.

  2. Description of the Related Art Conventionally, an assist bicycle that assists a human driving force with a motor is known. Some assist bicycles are provided with a motorized bicycle hub. 2. Description of the Related Art Conventionally, a motor-equipped bicycle hub is known in which a rotor is supported by a pair of left and right rolling bearings (see, for example, Patent Document 1).

JP 2005-335536 A

  For example, in consideration of assembly, when it is necessary to attach the outer ring to the rotor with a clearance fit, noise due to rattling of the outer ring may occur.

  An object of the present invention is to make it possible to suppress noise even when the outer ring of a bearing is attached to a rotor by a clearance fit in a motor-integrated bicycle hub.

  A motor-integrated bicycle hub according to a first aspect of the present invention is a motor-integrated bicycle hub that constitutes a hub of a bicycle wheel. The motor-integrated bicycle hub includes a hub shaft, a motor, a first bearing, a second bearing, a movement restricting portion, and a pressing portion. The motor includes a rotor that rotates about the hub shaft, and a stator that is non-rotatable with respect to the hub shaft and is disposed on the outer peripheral side of the rotor. The first bearing has a first inner ring, a first outer ring, and a first rolling element, and is for rotatably supporting the rotor on the hub shaft. The first inner ring is attached to the hub axle. The first outer ring is attached to the rotor. The first rolling element is disposed between the first inner ring and the first outer ring. The second bearing has a second inner ring, a second outer ring, and a second rolling element, and is disposed at a distance from the first bearing in the hub axis direction, and rotatably supports the rotor on the hub axis. Is. The second inner ring is attached to the hub axle. The second outer ring is attached to the rotor. The second rolling element is disposed between the second inner ring and the second outer ring. The movement restriction unit restricts movement of the first inner ring in a direction away from the second bearing. The pressing portion can press the first outer ring toward the second bearing.

  In this motor-integrated bicycle hub, the first outer ring is pressed toward the second bearing by the pressing portion. Further, the movement of the first inner ring in the direction away from the second bearing is restricted by the movement restricting portion. Thereby, even if the first outer ring is attached to the rotor with a clearance fit, only the first outer ring tries to move to the opposite side of the second bearing with respect to the first inner ring whose movement is restricted by the movement restricting member. Can be suppressed. By restricting the movement of the first outer ring to the opposite side of the second bearing, the play of the first outer ring can be suppressed, and noise can be suppressed even when the outer ring of the bearing is mounted on the rotor by clearance fitting.

  A motor-integrated bicycle hub according to a second aspect is the motor-equipped bicycle hub according to the first aspect, wherein the pressing portion includes a biasing member that biases the first outer ring.

  In this case, since the first outer ring can be pressed by the urging member such as the elastic body and the spring member, the first outer ring can be stably pressed.

  The motor-integrated bicycle hub according to a third aspect is the motor-equipped bicycle hub according to the second aspect, wherein the biasing member is a spring member.

  In this case, a spring member such as a coil spring or a disc spring can urge the first outer ring stably over a long period of time compared to an elastic body such as rubber.

  A motor-equipped bicycle hub according to a fourth aspect of the present invention is the motor-equipped bicycle hub according to any one of the first to third aspects, further comprising a speed reduction mechanism that decelerates the rotation of the rotor. The rotor is connected to a speed reduction mechanism.

  In this case, since the rotation of the motor is decelerated by the speed reduction mechanism, the rotational torque of the wheel can be increased.

  A motor-integrated bicycle hub according to a fifth aspect is the motor-equipped bicycle hub according to the fourth aspect, wherein the urging member has a first end in contact with the speed reduction mechanism and a second end in contact with the first outer ring.

  In this case, since the biasing member is in contact with a different member, the shape of the biasing member and the degree of freedom of arrangement are increased. Moreover, when arrange | positioning an urging member, the space produced between a deceleration mechanism can be utilized efficiently, and it can suppress that the hub for bicycles becomes large in order to arrange an urging member. .

  A bicycle hub with a built-in motor according to a sixth aspect of the invention is the bicycle hub with a built-in motor according to the fifth aspect, wherein the pressing portion is a first positioning portion attached to the speed reduction mechanism, and a second attached to the rotor so as to be axially movable. And a positioning part. The first positioning portion positions the first end side of the urging member in the radial direction of the hub shaft. The second positioning portion positions the second end side of the biasing member in the radial direction of the hub shaft.

  In this case, since the position of the urging member in the radial direction of the hub shaft is positioned, even if the rotor rotates and centrifugal force acts on the urging member, the urging member moves in a direction other than the urging direction. It becomes difficult and the urging force is stabilized.

  A bicycle hub with a built-in motor according to a seventh aspect is the bicycle hub with a built-in motor according to the fifth or sixth aspect, wherein the speed reduction mechanism is a planetary gear mechanism having a sun gear coupled to the rotor so as to be integrally rotatable. The first end of the urging member is in contact with the sun gear.

In this case, since the urging member contacts the sun gear that rotates integrally, when the rotor rotates, the urging member can be rotated together with the first outer ring, and the urging member and the first outer ring can be rotated. The bicycle hub with a built-in motor according to the eighth aspect of the present invention is capable of suppressing friction. In the bicycle hub with a built-in motor according to any of the first to seventh aspects, the movement restricting portion is formed to protrude from the outer peripheral surface of the hub shaft. And a protrusion capable of contacting the first inner ring.

  In this case, the movement of the first inner ring can be restricted with a simple configuration in which a protrusion is provided on the hub shaft.

  According to the present invention, the first outer ring on the movement restriction portion side is pressed toward the second bearing by the pressing portion. Further, the movement of the first inner ring in the direction away from the second bearing is restricted by the movement restricting portion. Thereby, even if the first outer ring is attached to the rotor with a clearance fit, only the first outer ring tries to move to the opposite side of the second bearing with respect to the first inner ring whose movement is restricted by the movement restricting member. Can be suppressed. By restricting the movement of the first outer ring to the opposite side of the second bearing, it is possible to suppress rattling of the first outer ring and to suppress noise even if the outer ring of the bearing is fitted to the rotor with a clearance fit. It becomes like this.

The perspective view of the hub with a built-in motor by one embodiment of the present invention. Sectional drawing of a motor built-in hub. The cross-sectional enlarged view of a rotor support part.

  In FIG. 1, a motor built-in hub 10 according to an embodiment of the present invention is used in an assist bicycle that assists driving by human power with a motor.

<Schematic configuration of motor built-in hub>
The motor built-in hub 10 constitutes a hub for a front wheel of a bicycle. The motor built-in hub 10 is attached to the front claw portion 103a at the tip of the front fork of the bicycle and assists driving by human power. As shown in FIG. 2, the motor built-in hub 10 includes a hub shaft 15, a motor 11, a first bearing 66a, a second bearing 66b, a spacer 67, a movement restricting portion 68, and a pressing portion 73. I have. The motor built-in hub 10 further includes a motor case 17 and a rotation transmission mechanism 25 housed in the motor case 17. The motor 11 includes a rotor 21 that rotates around the hub shaft 15 and a stator 22 that cannot rotate with respect to the hub shaft 15 and is disposed on the outer peripheral side of the rotor 21. The first bearing 66 a is a rolling bearing for rotatably supporting the rotor 21 on the hub shaft 15. The second bearing 66b is a rolling bearing that is disposed at a distance from the first bearing 66a in the hub axial direction, and rotatably supports the rotor 21 on the hub shaft 15. The movement restricting unit 68 restricts the movement of the first bearing 66a in the direction away from the second bearing 66b. The pressing portion 73 presses a later-described first outer ring 71b of the first bearing 66a toward the second bearing 66b.

<Hub shaft>
The hub shaft 15 is made of, for example, an iron-based metal such as steel that has not been quenched, and both ends of the hub shaft 15 can be attached to the front claw portion 103a so as not to rotate. A pair of left and right first male screw portions 15a and second male screw portions 15b, into which nut members 50 for fixing to the front claw portion 103a are screwed, are formed on the outer peripheral surfaces of both ends of the hub shaft 15. Moreover, the 1st latching | locking part 15c and the 2nd latching | locking part 15d which have two mutually parallel surfaces are formed in the outer peripheral surface of the 1st external thread part 15a and the 2nd external thread part 15b. A rotation locking portion 15e for non-rotatably connecting a first case member 32 described later of the motor case 17 is formed inside the second locking portion 15d in the hub axial direction. A nut member 50 and a first lock nut 51 are screwed into the first male screw portion 15a. A nut member 50 and a second lock nut 52 that fixes the first case member 32 to the hub shaft 15 are screwed into the second male screw portion 15b. In the axially inward direction of the nut member 50, the first locking portion 15c and the second locking portion 15d are individually engaged with the first locking portion 15c and the second locking portion 15d so as not to rotate. A non-rotating washer 54 is attached for stopping.

  In addition, a third male screw portion 15f into which a bearing 31 that rotatably supports a second end of a second case member 34, which will be described later, of the motor case 17 is screwed is formed inside the first male screw portion 15a in the hub axial direction. Has been. The intermediate portion of the hub shaft 15 has a larger diameter than the first male screw portion 15a and the second male screw portion 15b.

  A movement restricting portion 68 formed of a protrusion protruding from the outer peripheral surface is formed on the mounting portion of the first bearing 66 a of the hub shaft 15. In this embodiment, the movement restricting portion 68 is constituted by an annular protrusion 68a formed integrally with the hub shaft 15. The movement restricting portion 68 contacts a first inner ring 71a (described later) of the first bearing 66a, and restricts the movement of the first inner ring 71a in a direction away from the second bearing 66b.

<Motor case>
As shown in FIG. 2, the motor case 17 includes a first case member 32 that is non-rotatably connected to the hub shaft 15, a first end (right end in FIG. 2) on the first case member 32, The second case member 34 is rotatably supported at two ends (left end in FIG. 2). Second case member 34 is formed of, for example, an aluminum alloy.

  The first case member 32 includes a case main body 36 that is non-rotatably attached to the hub axle 15, and a cover member 38 that is fixed to the outer surface of the case main body 36. A space is formed between the cover member 38 and the case main body 36. The case main body 36 and the cover member 38 are made of, for example, an aluminum alloy.

  The case body 36 includes a first boss portion 36a that is non-rotatably connected to the hub axle 15, a circular partition wall portion 36b that is formed integrally with the first boss portion 36a, and a second case member from the outer periphery of the partition wall portion 36b. And a cylindrical first cylindrical portion 36c extending toward 34. A non-circular coupling hole 36d that is non-rotatably coupled to the rotation locking portion 15e of the hub shaft 15 is formed on the inner peripheral surface of the first boss portion 36a. The case main body 36 is non-rotatably fixed to the hub shaft 15 by the second lock nut 52.

  The outer surface of the partition part 36b is a substantially flat surface. A cylindrical portion 43d for adjusting the position of the stator 22 of the motor 11 is formed on the inner surface of the partition wall portion 36b. A plurality of (for example, three) screw holes 43e for fixing the stator 22 of the motor 11 with the bolt members 39 are spaced apart in the circumferential direction on the inner side surface of the partition wall portion 36b radially outward of the cylindrical portion 43d. Is formed. A plurality of (for example, three) attachment portions 43f are formed between the first cylindrical portion 36c and the cylindrical portion 43d of the partition wall portion 36b so as to be spaced apart in the circumferential direction.

  An inner ring 30a of a bearing 30 in the form of, for example, a ball bearing, which rotatably supports the first end of the second case member 34 is mounted on the outer peripheral surface of the first cylindrical portion 36c. A cylindrical gear mounting portion 35 that is non-rotatably connected to the first cylindrical portion 36c is positioned and fitted on the outer peripheral surface of the distal end portion of the first cylindrical portion 36c. The gear mounting portion 35 includes a cylindrical portion 35a having one end (right end in FIG. 2) fitted to the outer peripheral surface of the first cylindrical portion 36c, and an annular mounting portion 35b integrally formed on the inner peripheral surface of the cylindrical portion 35a. Have. On the inner peripheral surface of the other end (left end in FIG. 2) of the cylindrical portion 35a, there is a serration portion 35c to which an internal gear 48b, which will be described later, is connected in a non-rotatable manner. The gear attachment portion 35 is fixed to the three attachment portions 43f by bolt members 45.

  As shown in FIG. 1, the cover member 38 has a concave portion 32 a and a bulging portion 32 b on the outer surface. The recess 32a is formed to be slightly wider than the shape of the tip of a normal front fork so that various types of front forks can be inserted.

  As shown in FIG. 2, the second case member 34 has a structure similar to a hub shell of a normal bicycle hub, and is a member having a bottomed cylindrical portion. The second case member 34 includes a second boss part 34b supported by the bearing 31, a disk part 34c integrally formed with the second boss part 34b, and an inner part in the hub axial direction from the outer peripheral part of the disk part 34c. A second cylindrical portion 34d extending in a cylindrical shape.

  A bearing 31 is mounted on the inner peripheral surface of the second boss portion 34b between the second boss portion 34b and the hub shaft 15. The bearing 31 can be adjusted in axial position by the inner ring 31 a being screwed into a third male threaded portion 15 f formed on the hub shaft 15. The adjusted inner ring 31 a is prevented from rotating by the first lock nut 51. The outer ring 31b is attached to the inner peripheral surface of the second boss portion 34b.

  The second cylindrical portion 34d is disposed on the outer peripheral side of the first cylindrical portion 36c. The outer ring 30b of the bearing 30 is attached to the first end side inner peripheral surface of the second cylindrical portion 34d. A first hub flange 40a and a second hub flange 40b for connecting the rim of the front wheel and the motor built-in hub 10 by spokes are formed on the outer peripheral surface of the second cylindrical portion 34d with a gap at both ends in the hub axial direction. Has been.

<Motor>
As described above, the motor 11 includes the rotor 21 and the stator 22 disposed on the outer peripheral side of the rotor 21 so as to face the rotor 21.

  The rotor 21 is rotatably supported on the hub shaft 15. The rotor 21 includes, for example, a magnet 21a having a plurality of magnetic poles in the circumferential direction and a magnet holding portion 21b that holds the magnet 21a. The magnet holding portion 21b is rotatably supported on the hub shaft 15 by a first bearing 66a and a second bearing 66b that are arranged at an interval in the hub axis direction.

  The stator 22 is disposed on the outer peripheral side of the rotor 21. The stator 22 has a plurality of (for example, six) coil portions 46 that are fixed to the partition wall portion 36b of the case main body 36 and arranged at intervals in the circumferential direction. In addition, the stator 22 has an attachment portion 49 for fixing the coil portion 46. The attachment portion 49 functions as a yoke. The attachment portion 49 is a metallic cylindrical member, and has three fixing convex portions 49a on one end outer peripheral surface. The mounting portion 49 is attached to the outer peripheral surface of the centering cylinder portion 43d, and the inner peripheral surface is centered by the centering cylinder portion 43d. In this embodiment, the attachment portion 49 is fixed to the partition wall portion 36b by three bolt members 39 that pass through the convex portion 49a and are screwed into the screw holes 43e. The plurality of coil portions 46 are sequentially excited by alternating current switched by a motor control circuit (not shown) to rotate the rotor 21 in the traveling direction of the bicycle.

<First bearing and second bearing and spacer>
As shown in FIG. 3, the first bearing 66 a is disposed between the inner peripheral surface of the first end in the rotation axis direction of the rotor 21 and the outer peripheral surface of the hub shaft 15. The first bearing 66a includes a first inner ring 71a attached to the hub axle 15, a first outer ring 71b attached to the rotor 21, and a first rolling element disposed between the first inner ring 71a and the first outer ring 71b. 71c. As described above, the first inner ring 71a is disposed in contact with the movement restricting portion 68. The first inner ring 71 a is attached to the outer peripheral surface of the hub shaft 15 with an interference fit. Therefore, the first inner ring 71 a is fixed to the outer peripheral surface of the hub shaft 15 by being pressed into contact with the movement restricting portion 68. The first inner ring 71a is pressed toward the movement restricting portion 68 by a first inner ring pressing structure including the spacer 67, the second inner ring 72b, the first boss portion 36a, and the second lock nut 52. The first outer ring 71b has a clearance in a state in which movement toward the second bearing 66b side is restricted by a first bearing housing portion 21c formed by recessing the magnet holding portion 21b on the inner peripheral surface of the first end of the rotor 21. It is fitted with a fit. The side surface of the first outer ring 71b on the second bearing 66b side may be in contact with the stepped portion of the concave portion of the magnet holding portion 21b, or may be slightly separated from the stepped portion of the concave portion of the magnet holding portion 21b.

  The second bearing 66 b is disposed between the inner peripheral surface of the second end in the rotation axis direction of the magnet holding portion 21 b of the rotor 21 and the outer peripheral surface of the hub shaft 15. The second bearing 66b includes a second inner ring 72a attached to the hub axle 15, a second outer ring 72b attached to the rotor 21, and a second rolling element disposed between the second inner ring 72a and the second outer ring 72b. 72c. The second inner ring 72a is disposed with the first inner ring 71a and the spacer 67 interposed therebetween. The second inner ring 72a is attached to the outer peripheral surface of the hub axle 15 with a clearance fit. However, the second inner ring 72a is disposed between the spacer 67 and the first boss portion 36a of the case body 36 and cannot move in the hub shaft direction.

  In the hub shaft 15, when the inner diameters of the first inner ring and the second inner ring are the same, the second mounting portion 15h of the second inner ring 72a has a slightly smaller outer diameter than the first mounting portion 15g of the first inner ring 71a. small. Thereby, the 2nd inner ring | wheel 72a can be mounted | worn with clearance fit. In FIG. 3, the difference between the outer diameters of the first mounting portion 15 g and the second mounting portion 15 h is drawn larger than the actual one for easy understanding. When the inner diameter of the first inner ring is slightly larger than the inner diameter of the second inner ring, the second mounting portion 15h can have the same outer shape as the first mounting portion 15g. The second outer ring 72b is attached to the second bearing housing portion 21d formed by being recessed in the inner peripheral surface of the magnet holding portion 21b at the second end of the rotor 21 with a snug fit. Accordingly, the second outer ring 72b is fixed to the second bearing housing portion 21d by press fitting. The side surface of the second outer ring 72b on the first outer ring 71a side contacts the stepped portion of the concave portion of the magnet holding part 21b, and the second outer ring 72b is positioned.

  In the hub shaft 15, the step 15i between the second mounting portion 15h and the portion where the second male screw portion 15b is formed is the first bearing 66a from the end surface of the second bearing 66b opposite to the first bearing 66a. Located on the side. Further, a boundary portion 15j between the first mounting portion 15g and the second mounting portion 15h is located on the first bearing 66a side from the end surface on the first bearing 66a side of the second bearing 66b.

  The spacer 67 is a metallic cylindrical member disposed between the first inner ring 71a and the second inner ring 72a. The spacer 67 has an inner diameter larger than the outer diameter of the hub shaft 15. The outer diameter of the portion that contacts the first inner ring 71a of the spacer 67 only needs to be smaller than the inner diameter of the first outer ring 71b, and the outer diameter of the portion that contacts the second inner ring 72a of the spacer 67 is smaller than the inner diameter of the second outer ring 72b. Small is enough. In this embodiment, the outer diameter of the spacer 67 is smaller than the outer diameters of the first inner ring 71a and the second inner ring 72a. By the spacer 67, the movement of the second inner ring 72a of the second bearing 66b attached to the hub shaft 15 by clearance fitting is suppressed in the axial direction and the rotational direction. In order to realize this, the second lock nut 52 functions as a pressing member, and presses the second inner ring 72a toward the first inner ring 71a. As described above, the second lock nut 52 is for fixing the case main body 36 to the hub shaft. However, when the second lock nut 52 is tightened, the second lock nut 52 presses the case main body 36, and the first boss portion 36a of the case main body 36 presses the second inner ring 72a. When the second inner ring 72 a is pressed and comes into contact with the spacer 67, the spacer 67 cannot move any further, so that the second inner ring 72 a is pressed by the second lock nut 52. Thereby, the movement of the second inner ring 72a in the hub axial direction and the rotational direction is restricted. For this reason, the 1st inner ring 71a and the 2nd inner ring 72a become difficult to slip to hub axis 15, and hub axis 15, the 1st inner ring 71a, and the 2nd inner ring 72a become difficult to wear. Here, the case main body 36 is in contact with the second inner ring 72a. However, an annular member is provided between the case main body 36 and the second inner ring 72a, and the case main body 36 is connected to the second inner ring 72a via the annular member. It is good also as a structure which presses.

<Rotation transmission mechanism>
As illustrated in FIG. 2, the rotation transmission mechanism 25 transmits the rotation of the rotor 21 to the second case member 34 at a reduced speed. The rotation transmission mechanism 25 increases the rotation of the second case member 34 and transmits it to the rotor 21 during regenerative braking. The rotation transmission mechanism 25 has a planetary gear mechanism 48. The planetary gear mechanism 48 is an example of a speed reduction mechanism. The planetary gear mechanism 48 includes a sun gear 48a, an internal gear 48b disposed on the outer peripheral side of the sun gear 48a, and a plurality of (for example, three) planetary gears 48c that mesh with the sun gear 48a and the internal gear 48b. have. The sun gear 48 a has a connecting portion 48 e for connecting to the rotor 21. The connecting portion 48e is formed in a cylindrical shape, for example, and has a larger inner diameter than the portion where the teeth of the sun gear 48 are formed. The sun gear 48a is connected to the magnet holding portion 21b of the rotor 21 so as to be integrally rotatable by a bolt member 55 attached to the connecting portion 48e. The internal gear 48b is non-rotatably connected to the gear mounting portion 35 of the case body 36. The plurality of planetary gears 48c are rotatably supported by a carrier 48d. Each planetary gear 48c has two first gear portions 56a and second gear portions 56b having different numbers of teeth. The first gear portion 56a meshes with the sun gear 48a, and the second gear portion 56b meshes with the internal gear 48b. The carrier 48d is fixed to the inner surface of the disc portion 34c of the second case member 34. In this planetary gear mechanism 48, since the internal gear 48b provided in the case body 36 is fixed to the hub shaft 15 so as not to rotate, the rotation of the sun gear 48a to which the rotor 21 is coupled is decelerated to reduce the second case member. 34.

<Pressing part>
As shown in FIG. 3, the pressing portion 73 has a biasing member 74 whose first end in the rotation axis direction comes into contact with the sun gear 48a and whose second end comes into contact with the first outer ring 71b. The pressing portion 73 includes a first positioning portion 75 that positions the first end side of the biasing member 74 in the radial direction of the hub shaft 15, and a second end side of the biasing member 74 in the radial direction of the hub shaft 15. And a second positioning portion 76 for positioning. The biasing member 74 is disposed on the outer peripheral side of the hub shaft 15 and has a coil spring 74a as a spring member disposed in a compressed state between the sun gear 48a and the first outer ring 71b. The coil spring 74a can suppress the play of the first outer ring 71b fitted with a clearance.

The 1st positioning part 75 is a cylindrical member arrange | positioned at the inner peripheral side of the connection part 48e of the sun gear 48a, and has the 1st collar part 75a and the 1st cylinder part 75b. The first flange 75a extends in the radial direction, and the first flange 75a provided in contact with the inner peripheral surface of the connecting portion 48e may be fixed to the inner peripheral surface of the connecting portion 48e. The first cylindrical portion 75b extends from the inner peripheral portion of the first collar portion 75 in the axial direction of the hub shaft, and is disposed on the inner peripheral side of the coil spring 74a to position the coil spring 74a in the radial direction.
The 2nd positioning part 76 is a cylindrical member with a hook of the same shape as the 1st positioning part 75, and has the 2nd collar part 76a and the 2nd cylinder part 76b. The second positioning portion 76 is disposed on the inner peripheral portion of at least one of the rotor 21 and the connecting member 48e. The second positioning portion 76 is attached to the first bearing storage portion 21c of the magnet holding portion 21b so as to be movable in the hub axial direction. The second flange 76a is in contact with the end surface of the first outer ring 71b. Further, the second flange portion 76a is restricted from moving in the radial direction by the first bearing housing portion 21c. The second flange portion 76a may be provided in contact with the first bearing housing portion 21c. The second cylindrical portion 76b extends from the inner peripheral portion of the second flange portion 76 in the axial direction of the hub shaft, and is disposed on the inner peripheral side of the coil spring 74a to position the coil spring 74a in the radial direction.
Even if the rotor 21 rotates and the centrifugal force acts on the biasing member 74 by the first positioning portion 75 and the second positioning portion 76, the biasing member 74 becomes difficult to move in the direction other than the biasing direction, and the biasing force is reduced. Stabilize. Further, when the coil spring 74a is mounted between the sun gear 48a and the magnet holding portion 21b, the first positioning portion 75 and the second positioning portion 76 can prevent the coil spring 74a from falling off. Becomes easier.

<Motor installation procedure>
When the rotor 21 is incorporated into the hub shaft 15, the first bearing 66 a is first press-fitted into the first mounting portion 15 g of the hub shaft 15. At the time of press-fitting, the first inner ring 71 a is pressed using an appropriate jig until the first inner ring 71 a of the first bearing 66 a contacts the movement restricting portion 68. Further, the second outer ring 72b of the second bearing 66b is press-fitted into the second bearing housing portion 21d of the magnet holding portion 21b of the rotor 21. Also in this press-fitting, the second outer ring 72b is pressed using an appropriate jig until the second outer ring 72b of the second bearing comes into contact with the wall surface of the second bearing housing portion 21d. When the first bearing 66a is mounted on the hub shaft 15 and the second bearing 66b is mounted on the rotor 21, the spacer 67 is mounted on the outer peripheral side of the hub shaft 15 so as to be in contact with the first inner ring 71a. In this state, the rotor 21 to which the second bearing 66b is attached is attached to the hub shaft 15. At this time, the first outer ring 71b of the first bearing 66a is fitted into the first bearing housing portion 21c, and the second inner ring 72a of the second bearing 66b is fitted into the outer peripheral surface of the hub shaft 15.

  Next, the 1st positioning part 75 and the 2nd positioning part 76 are each mounted | worn with the cylindrical connection part 48e of the sun gear 48a, and the 1st bearing accommodating part c of the magnet holding | maintenance part 21b. And the coil spring 74a is arrange | positioned on the outer peripheral side of the 1st cylinder part 75b of the 1st positioning part 75, and the 2nd cylinder part 76b of the 2nd positioning part 76, and the sun gear 48a is made into the magnet holding | maintenance part 21b by the bolt member 55. Fix it. Accordingly, the coil spring 74a is compressed, and the first outer ring 71b is pressed toward the second bearing by the coil spring 74a. The backlash of the first outer ring 66a can be suppressed by restricting the movement of the first outer ring 71b to the opposite side to the second bearing 66b. For this reason, noise can be suppressed even if the first outer ring 71b of the first bearing 66a is attached to the rotor 21 with a clearance fit.

  Then, the first boss portion 36 a of the case main body 36 to which the stator 22 is mounted in advance is engaged with the rotation locking portion 15 e of the hub shaft 15. Next, the second boss portion 36a presses the second inner ring 72a by screwing the second lock nut 52 into the second male screw portion 15b and tightening it. After the pressed second inner ring 72a contacts the spacer 67, when the second lock nut 52 is further tightened, the second inner ring 72a is interposed between the spacer 67 and the first boss part 36a via the first boss part 36a. Pressed. This restricts the movement of the second inner ring 72a in the hub axial direction and the rotational direction. As a result, wear of the hub shaft 15 and the second inner ring 72a can be reduced.

<Other embodiments>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.

  (A) In the embodiment described above, the motor built-in hub for the front wheels is disclosed, but the present invention can also be applied to a motor built-in hub for the rear wheels.

  (B) Although the ball bearing is illustrated as the rolling bearing in the embodiment, the rolling bearing is not limited to the ball bearing.

  (C) The mechanical configuration of the motor 11 is not limited to the above configuration. For example, in the above-described embodiment, the motor is an inner rotor, but it may be an outer rotor motor.

  (D) In the embodiment described above, the protrusion of the movement restricting portion 68 is an annular protrusion integrally formed with the hub shaft, but the present invention is not limited to this. For example, the protrusion may be integral with or separate from the hub axle. Moreover, the protrusion should just protrude from an outer peripheral surface and can restrict | limit the movement of a 1st inner ring | wheel, for example, multiple may be provided radially. However, the annular protrusion formed integrally is easy to machine and can reduce the cost.

  (E) In the above embodiment, the pressing portion 73 is disposed between the sun gear 48a and the first outer ring 71b, but the present invention is not limited to this. For example, as the pressing portion 73, one end is locked to the inner peripheral surface of the first bearing storage portion 21c, and the other end is in contact with the first outer ring 71b, or a spring member such as a disc spring or a corrugated spring, or an elastic member such as rubber. You may place your body. Therefore, the spring member is not limited to the coil spring, and may be the above-described disc spring or corrugated spring. A bamboo shoot spring or the like can also be used.

  (F) In the above embodiment, the spring member is exemplified as the urging member used for the pressing portion. However, the pressing member may be any member as long as it can press the first outer ring 71b toward the second bearing 66b. Good. For example, a female screw portion may be formed on the inner peripheral surface of the first bearing housing portion 21c, and a screw member may be screwed into the female screw portion to press the first outer ring 71b.

DESCRIPTION OF SYMBOLS 10 Motor built-in hub 11 Motor 15 Hub shaft 21 Rotor 22 Stator 48 Planetary gear mechanism 48a Sun gear 66a 1st bearing 66b 2nd bearing 68 Movement restriction part 68a Annular protrusion 71a 1st inner ring 71b 1st outer ring 71c 1st rolling element 72a 1st 2 inner ring 72b 2nd outer ring 72c 2nd rolling element 73 Press part 74 Energizing member 74a Coil spring 75 1st positioning part 76 2nd positioning part

Claims (8)

A bicycle hub with a built-in motor that constitutes a hub of a bicycle wheel,
A hub axle,
A motor having a rotor that rotates about the hub shaft, and a stator that is non-rotatable with respect to the hub shaft and is disposed on the outer peripheral side of the rotor;
A first inner ring mounted on the hub axle, a first outer ring mounted on the rotor by a clearance fit, and a first rolling element disposed between the first inner ring and the first outer ring, A first bearing for rotatably supporting the rotor on the hub shaft;
A second inner ring attached to the hub axle; a second outer ring attached to the rotor; a second rolling element disposed between the second inner ring and the second outer ring; A second bearing disposed at a distance from the first bearing and for rotatably supporting the rotor on the hub axle;
A movement restricting portion for restricting movement of the first inner ring in a direction away from the second bearing;
A pressing portion capable of pressing the first outer ring toward the second bearing;
Bicycle hub with built-in motor.   2. The motor-integrated bicycle hub according to claim 1, wherein the pressing portion includes a biasing member that biases the first outer ring.   The bicycle built-in bicycle hub according to claim 2, wherein the biasing member is a spring member. A further reduction mechanism for reducing the rotation of the rotor;
The motor built-in bicycle hub according to any one of claims 1 to 3, wherein the rotor is connected to the speed reduction mechanism.   5. The motor-integrated bicycle hub according to claim 4, wherein the biasing member has a first end in contact with the speed reduction mechanism and a second end in contact with the first outer ring. The pressing portion is
A first positioning portion mounted on the speed reduction mechanism and positioning the first end side of the biasing member in a radial direction of the hub shaft;
The bicycle with a built-in motor according to claim 5, further comprising: a second positioning portion that is attached to the rotor so as to be movable in the axial direction and positions the second end side of the biasing member in a radial direction of the hub shaft. For hub. The speed reduction mechanism is a planetary gear mechanism having a sun gear coupled to the rotor so as to be integrally rotatable,
The bicycle built-in hub according to claim 5 or 6, wherein the first end of the biasing member is in contact with the sun gear.   The motor-integrated bicycle hub according to any one of claims 1 to 7, wherein the movement restricting portion is formed to protrude from an outer peripheral surface of the hub axle and has a protrusion that can contact the first inner ring.

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