CN114301227A - Motor device - Google Patents

Abstract

The invention provides a technology capable of reducing the axial size of a brake. The motor device of the present invention includes: a motor; a brake that brakes rotation of the motor shaft (14); and a brake housing (34) that houses a brake, wherein the brake includes: a brake shoe (58); and a pressing mechanism (60) which presses the brake shoe (58) toward the outer periphery of the motor shaft (14), wherein when the pressing mechanism (60) presses the brake shoe (58) toward the outer periphery of the motor shaft (14), the brake shoe (58) moves in the direction of rotation of the motor shaft along with the rotation of the motor shaft (14), and the brake shoe (58) is sandwiched between the motor shaft (14) and the brake housing (34), thereby braking the rotation of the motor shaft (14).

Description

Motor device

The present application claims priority based on japanese patent application No. 2020 and 169887, filed on 7/10/2020. The entire contents of this Japanese application are incorporated by reference into this specification.

Technical Field

The present invention relates to a motor device.

Background

Patent document 1 discloses a motor device incorporating a disc brake as a brake. The disc brake generally includes: a brake rotor rotating together with the motor shaft; and a brake shoe pressed against the brake rotor to brake the motor shaft.

Patent document 1: japanese laid-open patent publication No. 10-225064

When a disc brake is used as the brake, a brake rotor needs to be arranged in the axial direction with respect to a brake shoe in order to brake the rotation of the motor shaft. Therefore, the axial dimension of the entire brake tends to increase. The present inventors have found that the prior art has room for improvement from the viewpoint of downsizing the axial dimension of the brake.

Disclosure of Invention

An object of the present invention is to provide a technique capable of reducing the axial dimension of a brake.

The motor device of the invention comprises: a motor that rotates a motor shaft; a brake that brakes rotation of the motor shaft; and a brake housing accommodating the brake, wherein the brake includes: a brake shoe; and a pressing mechanism that presses the brake shoe toward an outer periphery of the motor shaft, wherein when the pressing mechanism presses the brake shoe toward the outer periphery of the motor shaft, the brake shoe moves in a rotational direction of the motor shaft in accordance with rotation of the motor shaft, and the brake shoe is sandwiched between the motor shaft and the brake housing, thereby braking rotation of the motor shaft.

According to the present invention, the axial dimension of the brake can be reduced.

Drawings

Fig. 1 is a side sectional view of a motor device of embodiment 1.

Fig. 2 is a view showing a part of a section a-a of fig. 1.

Fig. 3 is an enlarged view of fig. 2.

Fig. 4 is a perspective view of a brake shoe of embodiment 1.

Fig. 5 is an enlarged view showing a state in the middle of the movement of the brake shoe from the brake release position to the braking position in the motor device according to embodiment 1.

Fig. 6 is an enlarged view showing a state where the brake shoe is located at the braking position in the motor device according to embodiment 1.

Fig. 7 is an enlarged view showing a state in the middle of the movement of the brake shoe from the braking position to the brake release position in the motor device according to embodiment 1.

Fig. 8 is a schematic diagram showing a state in which a brake shoe is located at a brake release position in the motor device according to embodiment 2.

Fig. 9 is a schematic view showing a state in which a brake shoe is located at a braking position in the motor device according to embodiment 2.

Fig. 10 is an enlarged view of the range a of fig. 9.

Fig. 11 is a schematic view of the motor device of embodiment 3 when viewed from the same perspective as fig. 3.

Fig. 12 is a schematic diagram showing a state where braking by the brake shoes is released in the motor device according to embodiment 4.

Fig. 13 is a schematic diagram showing a state where braking is performed by a brake shoe in the motor device according to embodiment 4.

In the figure: 10-motor means, 12-industrial robot, 12A-joint, 14-motor shaft, 16-motor, 18-brake, 20-housing, 22-reduction gear, 34-brake housing, 56A, 56B-wedge, 58-brake shoe, 60-pressing mechanism, 68A, 68B-clamped part, 70A-1 st brake abutment surface, 70B-2 nd brake abutment surface, 72A-abutted surface, 74-non-brake abutment surface, 76-pressing member, 100A, 100B-forcing member, 130A, 130B-roller.

Detailed Description

Hereinafter, embodiments will be described. The same constituent elements are denoted by the same reference numerals, and redundant description thereof is omitted. In the drawings, components are appropriately omitted, enlarged, or reduced for convenience of description. The drawings are viewed in the direction of the symbols.

(embodiment 1)

Refer to fig. 1. The motor device 10 of the present embodiment is incorporated in the joint portion 12a of the industrial robot 12. The industrial robot 12 of the present embodiment is a cooperative robot that works in cooperation with a human.

The motor device 10 of the present embodiment mainly includes a motor shaft 14, a motor 16, a brake 18, a housing 20, and a reduction gear 22.

The motor shaft 14 transmits rotational power generated by the motor 16 to a driven member (not shown). The driven member of the present embodiment is the 2 nd arm of the industrial robot 12 connected to the 1 st arm via the joint 12 a. Hereinafter, the direction along the rotation center line CL of the motor shaft 14 is referred to as an axial direction X, and the circumferential direction and the radial direction of a circle centered on the rotation center line CL are referred to as a "circumferential direction" and a "radial direction", respectively. One side in the axial direction X (left side in fig. 1) is referred to as an output side, and the other side in the axial direction X (right side in fig. 1) is referred to as an opposite output side.

The motor 16 is capable of rotating the motor shaft 14. The motor 16 includes: a stator 24 fixed to a motor case 32 (described later); and a rotor 26 that rotates integrally with the motor shaft 14. The motor 16 of the present embodiment is a servo motor, and includes a motor control unit 28 (e.g., a motor actuator) that controls rotation of the motor 16, and a phase detection unit 30 (e.g., an encoder) that detects a rotational phase of the motor shaft 14.

The brake 18 can brake rotation of the motor shaft 14. The brake 18 is disposed on the output side with respect to the motor 16. The brake 18 is disposed between the motor 16 and the reduction gear 22. The specific structure of the stopper 18 will be described later.

The housing 20 is supported by a support member (not shown) disposed outside the motor device 10. The support member is, for example, the 1 st arm of the industrial robot 12. The housing 20 includes a motor housing 32 that houses the motor 16 and a brake housing 34 that houses the brake 18. The brake housing 34 of the present embodiment is configured as a part of the same components as the motor housing 32. In addition, the brake housing 34 may be configured separately from the motor housing 32. The brake housing 34 rotatably supports the motor shaft 14 via a1 st bearing 36.

The reduction gear 22 reduces the rotation of the motor shaft 14 and outputs the reduced rotation to the driven member. The reduction gear unit 22 includes: a speed reduction mechanism 38 that reduces the rotation of the motor shaft 14; a housing 40 that houses the speed reduction mechanism 38; and an output member 42 that outputs the rotational power decelerated by the deceleration mechanism 38 to the driven member.

The speed reduction mechanism 38 of the present embodiment is a flexural-engagement type speed reduction mechanism that causes the external gear 46 that is engaged with the internal gear member 44 to flex and deform and move, thereby causing the external gear 46 to rotate and transmitting its rotation component to the output member 42. Such a speed reducing mechanism 38 is well known per se, and therefore will not be described in detail here.

The housing 40 is fixed to the brake housing 34 by bolts or the like, and is integrated with the brake housing 34. The output member 42 of the present embodiment is a carrier 48 disposed on the output side with respect to the speed reducing mechanism 38. The reduction gear 22 further includes a2 nd bearing 50 disposed between the carrier 48 and the motor shaft 14.

Next, the features of the brake 18 will be explained. Refer to fig. 2 to 4. Hereinafter, hatching of the brake housing 34 and the brake shoe 58 is omitted for convenience of description.

The brake housing 34 includes a shoe accommodating portion 52 that accommodates a brake shoe 58 (described later). The shoe accommodating portion 52 is disposed radially outward with respect to the motor shaft 14. The shoe housing 52 includes a housing recess 54 recessed radially outward from an inner peripheral surface of the shoe housing 52.

In the shoe housing 52, wedge-shaped spaces 56A, 56B are formed between the brake housing 34 and the motor shaft 14. The interval of the wedge-shaped spaces 56A, 56B is set to become narrower toward one side in the circumferential direction. The "interval of the wedge-shaped space" in the present specification means: the radial spacing between the brake housing 34 and the motor shaft 14. The wedge-shaped spaces 56A, 56B include: a1 st wedge-shaped space 56A provided on one side in the circumferential direction (the counterclockwise direction side in the drawing) with respect to the accommodation recess 54; and a2 nd wedge-shaped space 56B provided on the other side in the circumferential direction (clockwise side in the drawing) with respect to the accommodation recess 54.

The brake 18 includes: a brake shoe 58; and a pressing mechanism 60 for pressing the brake shoe 58 toward the outer periphery of the motor shaft 14.

The brake shoe 58 of the present embodiment includes: a main body 62 that presses against the outer periphery of the motor shaft 14; and a protrusion 64 protruding radially outward from the body 62. The projecting portion 64 of the brake shoe 58 includes a pair of projecting portions 64 projecting from the edge portions on both axial sides of the outer peripheral surface of the main body portion 62.

The main body portion 62 includes a braking surface 66 that is pressed against the outer periphery of the motor shaft 14 to brake the motor shaft 14. The braking surface 66 is radially opposed to the outer periphery of the motor shaft 14. The braking surface 66 of the present embodiment has an arc shape matching the circular shape of the outer peripheral surface of the motor shaft 14. The braking surface 66 may be in surface contact with the outer circumferential surface of the motor shaft 14.

The main body 62 includes clamped portions 68A and 68B disposed in the wedge-shaped spaces 56A and 56B. The nipped parts 68A, 68B of the present embodiment include: a1 st clamped portion 68A disposed in the 1 st wedge-shaped space 56A; and a2 nd clamped portion 68B disposed in the 2 nd wedge-shaped space 56B. The clamped portions 68A, 68B of the present embodiment are wedge-shaped, in which the radial dimension thereof becomes thinner toward the side where the interval between the wedge-shaped spaces 56A, 56B becomes narrower.

The clamped portions 68A, 68B include brake contact surfaces 70A, 70B that contact the brake housing 34 during braking. The brake abutment surfaces 70A, 70B radially face the shoe housing 52 of the brake housing 34. The braking contact surfaces 70A, 70B are provided on the pair of clamped portions 68A, 68B, respectively. The braking contact surfaces 70A and 70B are convex curved surfaces. The braking abutment surfaces 70A, 70B include: a1 st brake contact surface 70A provided on the side where the interval in the wedge-shaped spaces 56A, 56B is narrowed; and a2 nd braking contact surface 70B provided on a side where the interval in the wedge-shaped spaces 56A, 56B is widened.

The shoe housing 52 of the brake housing 34 includes contacted surfaces 72A, 72B that are contacted with the brake contact surfaces 70A, 70B of the brake shoe 58. The abutted surfaces 72A, 72B include: a1 st contacted surface 72A provided on a side where the interval in the wedge-shaped spaces 56A and 56B is narrowed; and a2 nd contact surface 72B provided on a side where the interval in the wedge-shaped spaces 56A and 56B is widened. The contacted surfaces 72A and 72B have a curvature radius larger than that of the curved surfaces of the braking contact surfaces 70A and 70B. In order to satisfy this condition, the contacted surfaces 72A and 72B of the present embodiment are flat surfaces having infinite curvature radii. In addition, in order to satisfy this condition, the contacted surfaces 72A and 72B may be curved concave surfaces.

The brake shoe 58 includes a non-brake contact surface 74 that contacts the brake housing 34 during non-braking. Here, "at the time of non-braking" means: when the brake of the motor shaft 14 by the brake shoe 58 is released. In order to satisfy this condition, the brake shoe 58 may be in contact with the brake housing 34 at least when the brake shoe 58 is moved in the retraction direction Db2 (described later) of the pressing member 76. The non-brake contact surfaces 74 are provided on the pair of clamped portions 68A, 68B, respectively. The non-braking abutment surface 74 is provided between the 1 st braking abutment surface 70A and the 2 nd braking abutment surface 70B.

The non-braking contact surface 74 has a shape capable of surface-contacting the brake housing 34 during non-braking. To satisfy this condition, the non-brake contact surface 74 has the same planar shape as the contacted surface 72B of the brake housing 34. In addition, in order to satisfy this condition, when the contacted surface 72B has a concave curved surface, the non-braking contact surface 74 may have a convex curved surface with the same curvature as that of the curved surface of the contacted surface 72B.

The pressing mechanism 60 includes: a pressing member 76 that can advance and retreat with respect to the motor shaft 14; a non-electric drive unit 78 for driving the pressing member 76 to move in the 1 st driving direction Da1 without using electric power; and an electric driving unit 80 for driving the pressing member 76 to move in the 2 nd driving direction Da2 by using electric power. At least a part of the pressing mechanism 60 is disposed in the accommodation recess 54 of the brake housing 34. In the present embodiment, the pressing member 76, the electric drive portion 80, and the non-electric drive portion 78 are all accommodated in the accommodation recess 54.

The pressing member 76 of the present embodiment is a rod 84 (described later) of the electric drive unit 80. The pressing member 76 is disposed radially outward of the motor shaft 14. The brake shoe 58 is coupled to the pressing member 76 via a positioning pin 82, and is movable forward and backward in the forward and backward direction Db together with the pressing member 76. The positioning pin 82 is inserted through a pin hole 64a formed in the projection 64 of the brake shoe 58. The pin hole 64a is a long hole extending in the circumferential direction, which allows relative movement of the brake shoe 58 in the circumferential direction with respect to the positioning pin 82. Thereby, the brake shoe 58 is coupled to the pressing member 76 via the positioning pin 82 so as to be movable in the circumferential direction with respect to the pressing member 76.

The advancing/retreating direction Db of the pressing member 76 is a radial direction. Specifically, the advancing direction Db1 of the pressing member 76 is a radially inward direction, and the retracting direction Db2 of the pressing member 76 is a radially outward direction. When the pressing member 76 moves in the forward direction Db1 with respect to the motor shaft 14, the brake shoe 58 can be pressed toward the outer periphery of the motor shaft 14.

The 1 st driving direction Da1 of the non-electric driving unit 78 and the 2 nd driving direction Da2 of the electric driving unit 80 are opposite to each other in the advancing and retreating direction Db. In the present embodiment, the 1 st driving direction Da1 is the forward direction Db1, and the 2 nd driving direction Da2 is the retreat direction Db 2.

The non-electric drive portion 78 of the present embodiment is an elastic member that drives the pressing member 76 based on the restoring force of elastic deformation. A specific example of the non-electric drive section 78 formed of the elastic member is a compression spring. The non-motor drive portion 78 is disposed in an actuator case 90 described later and between the actuator case 90 and the rod 84.

The electric drive unit 80 of the present embodiment is a solenoid actuator (linear actuator). The electric drive unit 80 includes: a rod 84 capable of advancing and retreating; a coil 86 that generates a magnetic force that moves the rod 84; and an actuator housing 88, support rod 84 and coil 86. The actuator case 88 includes: an actuator housing 90 that houses the stem 84; and a frame 92 disposed outside the actuator casing 90 and supporting the actuator casing 90.

The electric drive unit 80 switches whether or not to energize its own coil 86 under the control of a brake control unit, not shown. The brake control unit is a computer that combines hardware such as a CPU, ROM, and RAM and software.

The non-electric drive unit 78 applies the 1 st driving force Fa in the advancing direction Db1 (the 1 st driving direction Da1) to the pressing member 76 regardless of whether or not the electric drive unit 80 is energized. The electric drive unit 80 applies a2 nd driving force Fb in the retraction direction Db2 (the 2 nd driving direction Da2) to the pressing member 76 when the coil 86 of the electric drive unit 80 is in the energized state. The 1 st driving force Fa functions as a force that presses the pressing member 76 in the forward direction Db1, and the 2 nd driving force Fb functions as a force that returns the pressing member 76 in the retraction direction Db 2. The 2 nd driving force Fb of the electric driving portion 80 is set to be larger than the 1 st driving force Fa of the non-electric driving portion 78. As a result, when the electric driving unit 80 is in the energized state, the 2 nd driving force Fb drives the pressing member 76 in the retracting direction Db2 (the 2 nd driving direction Da2) against the 1 st driving force Fa. On the other hand, when the electric driving unit 80 is in the non-energized state, the 2 nd driving force Fb is released, and the 1 st driving force Fa drives the pressing member 76 in the advancing direction Db1 (the 1 st driving direction Da 1).

Next, the operation of the motor device 10 related to the brake 18 will be described.

Refer to fig. 3 and 6. Fig. 3 and 6 show enlarged partial views of the respective drawings. The pressing mechanism 60 can move the brake shoe 58 between a braking position Pa (refer to fig. 6) and a brake release position Pb (refer to fig. 3). When the brake shoe 58 is located at the brake position Pa, the rotation of the motor shaft 14 is braked, and when it is located at the brake release position Pb, the braking of the motor shaft 14 is released. When the brake shoe 58 is disposed at the brake release position Pb, a very small gap 96 is formed between the brake shoe 58 and the motor shaft 14. The gap 96 is, for example, 0.3mm or less.

First, an operation when the brake 18 brakes the rotation of the motor shaft 14 will be described. Refer to fig. 3. When braking the rotation of the motor shaft 14, the pressing mechanism 60 drives the brake shoe 58 located at the brake release position Pb to move in the forward direction Db 1. In order to satisfy this condition, the pressing mechanism 60 of the present embodiment moves the pressing member 76 in the forward direction Db1 by releasing the energization of the electric drive unit 80 under the control of the brake control unit 94. Thereby, the brake shoe 58 is moved in the advancing direction Db1 together with the pressing member 76, and the brake shoe 58 is pressed toward the outer periphery of the motor shaft 14 by the pressing member 76.

Refer to fig. 5. When the brake shoe 58 is pressed against the outer periphery of the motor shaft 14, the brake shoe 58 moves in the rotational direction Dc of the motor shaft 14 to be braked (hereinafter, simply referred to as brake rotational direction Dc) in accordance with the rotation of the motor shaft 14 by friction between the brake shoe 58 and the motor shaft 14. Thereby, the clamped portion 68A of the brake shoe 58 on the brake rotation direction Dc side moves toward the side where the gap is narrowed (counterclockwise in the drawing) in the wedge-shaped space 56A where the clamped portion 68A is arranged.

When the brake shoe 58 moves along with the motor shaft 14, the 1 st brake abutment surface 70A of the brake shoe 58 first abuts against the brake housing 34. At this time, the 1 st brake abutment surface 70A abuts the 1 st contacted surface 72A of the brake housing 34. On the other hand, at this time, the 2 nd brake abutment surface 70B of the brake shoe 58 does not abut on the brake housing 34.

Refer to fig. 6. Thereafter, the brake shoe 58 moves further in the brake rotation direction Dc along with the motor shaft 14. As a result, the 2 nd brake abutment surface 70B abuts against the brake housing 34 after the brake housing 34 abuts against the 1 st brake abutment surface 70A. At this time, the 2 nd brake abutment surface 70B abuts the 2 nd contacted surface 72B of the brake housing 34. At this time, the 1 st brake abutment surface 70A is maintained in abutment with the brake housing 34.

As a result, the brake shoe 58 is disposed at the braking position Pa sandwiched between the motor shaft 14 and the brake housing 34. At this time, the clamped portion 68A of the brake shoe 58 located on the brake rotation direction Dc side is clamped between the motor shaft 14 and the brake housing 34 in the wedge-shaped space 56A in which the clamped portion 68A is arranged. Thus, the rotation of the motor shaft 14 can be braked by the brake shoe 58. It can also be said that during braking, the brake shoe 58 is sandwiched between the motor shaft 14 and the brake housing 34 in the wedge-shaped spaces 56A, 56B.

The pressing force applied to the brake shoe 58 by the pressing mechanism 60 is set to a magnitude that can maintain a state in which the brake shoe 58 is pressed against the outer periphery of the motor shaft 14 even when the motor shaft 14 rotates at the expected maximum rotation speed. In the present embodiment, the magnitude of the 1 st driving force Fa (see fig. 2) of the non-electric driving portion 78 is set to satisfy this condition.

Next, the operation when the brake 18 releases the brake on the motor shaft 14 will be described.

When the brake on the motor shaft 14 is released, the pressing mechanism 60 drives the brake shoe 58 located at the braking position Pa in the retreat direction Db 2. In order to satisfy this condition, the pressing mechanism 60 of the present embodiment energizes the electric drive unit 80 under the control of the brake control unit 94, and drives the pressing member 76 in the retraction direction Db 2. The brake shoe 58 of the present embodiment is coupled to the pressing member 76, and therefore can move in the retraction direction Db2 together with the pressing member 76.

Refer to fig. 7. When the brake shoe 58 attempts to move in the retraction direction Db2, the non-brake contact surface 74 of the brake shoe 58 contacts the contacted surfaces 72A and 72B of the brake housing 34, and the brake shoe 58 is guided in a direction Dd opposite to the brake rotation direction Dc (hereinafter, simply referred to as the reverse direction Dd). The "reverse rotation direction Dd" is a side (clockwise in the drawing) where the interval of the wedge-shaped spaces 56A located on the brake rotation direction Dc side in the circumferential direction is widened. As a result, the brake shoe 58 moves radially outward (in the retreat direction Db2) in accordance with the movement in the reverse direction Dd, and moves from the braking position Pa to the braking release position Pb (see fig. 3).

The brake shoe 58 is held at the brake release position Pb in a state where the pressing mechanism 60 applies the 2 nd driving force Fb. At this time, the non-brake contact surfaces 74 provided on the pair of clamped portions 68A, 68B of the brake shoe 58 are in surface contact with the contacted surfaces 72A, 72B of the brake housing 34.

The operation related to braking of the motor shaft 14 when the braking rotation direction Da of the motor shaft 14 is one side in the circumferential direction (counterclockwise direction in the drawing) is described above. At this time, as described above, the brake shoe 58 moves toward one side in the circumferential direction along with the motor shaft 14. At this time, the 1 st clamped portion 68A of the brake shoe 58 is clamped between the motor shaft 14 and the brake housing 34 in the 1 st wedge space 56A, thereby braking the motor shaft 14. On the other hand, a case where the braking rotational direction Db of the motor shaft 14 is the other side in the circumferential direction (clockwise direction in the drawing) can be considered. At this time, the brake shoe 58 moves toward the other side in the circumferential direction along with the motor shaft 14. At this time, the 2 nd clamped portion 68B of the brake shoe 58 is clamped between the motor shaft 14 and the brake housing 34 in the 2 nd wedge space 56B, thereby braking the motor shaft 14. At this time, only the moving directions of the brake shoes 58 when braking the motor shaft 14 are different from each other in the circumferential direction, as compared with the case where the braking rotation direction Da of the motor shaft 14 is one side in the circumferential direction.

When the brake on the motor shaft 14 is released, the brake shoe 58 may strongly bite between the brake housing 34 and the motor shaft 14 in the wedge-shaped spaces 56A and 56B. At this time, the motor control unit 28 can rotate the motor shaft 14 in the direction Dd (reverse direction Dd) opposite to the braking rotation direction Dc. This releases the brake shoe 58 from being engaged with the brake shoe 58, and the electric drive unit 80 easily moves the brake shoe 58 in the retreat direction Db 2.

As described above, the pressing mechanism 60 can move the brake shoe 58 from the brake release position Pb toward the braking position Pa by moving the brake shoe 58 in the advancing direction Db1 together with the pressing member 76. On the other hand, the pressing mechanism 60 can move the brake shoe 58 from the braking position Pa to the brake release position Pb by moving the pressing member 76 in the retraction direction Db 2.

Refer to fig. 2. The pressing mechanism 60 of the present embodiment brakes the motor shaft 14 with the brake shoe 58 by the 1 st driving force Fa by the non-electric driving unit 78 in a state where the 2 nd driving force Fb is not applied by the electric driving unit 80. On the other hand, the pressing mechanism 60 releases the brake of the brake shoe 58 on the motor shaft 14 in a state where the electric drive unit 80 applies the 2 nd driving force Fb. In other words, the pressing mechanism 60 can switch the presence or absence of braking of the motor shaft 14 by the brake shoe 58 only when the electric drive unit 80 is supplied with electric power. On the other hand, the pressing mechanism 60 cannot switch the braking of the motor shaft 14 by the brake shoe 58 when the electric drive unit 80 is not supplied with electric power, and the motor shaft 14 can be continuously braked by the brake shoe 58.

Next, the effect of the motor device 10 will be described.

(A) According to the motor device of the present embodiment, the pressing mechanism 60 can brake the rotation of the motor shaft 14 by pressing the brake shoe 58 toward the outer periphery of the motor shaft 14. Accordingly, when braking the rotation of the motor shaft 14, a disc rotor such as a disc brake is not required, and therefore the axial dimension of the brake 18 can be reduced accordingly.

In addition, since the disc rotor is not required, the cost and weight of the brake 18 can be reduced, and the inertia of the motor shaft 14 can be reduced.

Even if the motor shaft 14 rotates when the brake shoe 58 brakes the rotation of the motor shaft 14, the brake housing 34, the motor shaft 14, the brake shoe 58, and the like elastically deform to absorb the braking force or the reaction force acting on the brake shoe 58 and the like. This makes it difficult for a locally large load to be applied to the brake shoe 58 or its peripheral structure, and good durability can be obtained.

Further, by moving the pressing member 76 forward and backward in the radial direction, the rotation of the motor shaft 14 can be braked. This eliminates the need to secure a space for advancing and retracting the pressing member 76 in the axial direction X, as in the case of a disk brake, and accordingly, the axial dimension of the brake 18 can be reduced.

(B) During braking, the brake shoes 58 are sandwiched between the motor shaft 14 and the brake housing 34 in the wedge-shaped spaces 56A, 56B. As a result, a strong braking force can be applied to the motor shaft 14 as described below.

Refer to fig. 6. The frictional force acting on the brake shoe 58 between the brake shoe 58 and the motor shaft 14 is Fr [ N ], the pressing force (hereinafter referred to as main pressing force) applied to the brake shoe 58 by the pressing mechanism 60 is Fn [ N ], and the coefficient of dynamic friction is μ [ - ]. A relationship of the following formula (1) is established between them.

Fr＝μ×Fn (1)

The clamped portion 68A of the brake shoe 58 is clamped in the wedge-shaped space 56A located on the brake rotation direction Dc side. Thus, a part of the frictional force Fr acting on the brake shoe 58 is converted into the auxiliary pressing force Fm that presses the brake shoe 58 toward the outer periphery of the motor shaft 14 by the shoe accommodating portion 52 (the contacted surfaces 72A, 72B) of the brake housing 34. As a result, the auxiliary pressing force Fm is present in addition to the main pressing force Fn, and therefore the braking force by the brake shoe 58 can be increased accordingly. As a result, a strong braking force can be applied to the motor shaft 14 by the brake shoe 58.

The auxiliary pressing force Fm has a positive correlation with the frictional force Fr. Similarly, as shown in the formula (1), the frictional force Fr has a positive correlation with the main thrust force Fn. Thus, when the main pressing force Fn is increased, the auxiliary pressing force Fm can be effectively increased. According to this relationship, a very strong braking force can be imparted to the motor shaft 14 by the brake shoe 58. Since a strong braking force can be ensured by the auxiliary pressing force Fm, power consumption of the electric drive unit 80 can be reduced while the braking force is ensured.

The brake shoe 58 is preferably disposed vertically above the motor shaft 14. This can increase the dynamic friction force Fr of equation (1) corresponding to the weight of the brake shoe 58.

The brake contact surfaces 70A, 70B of the brake shoe 58 are convexly curved, and the contacted surfaces 72A, 72B of the brake housing 34 are shaped to have a radius of curvature larger than that of the brake contact surfaces 70A, 70B. Thus, the contact area between the contacted surfaces 72A, 72B of the brake housing 34 and the brake contact surfaces 70A, 70B of the brake shoe 58 can be reduced as compared to the case where the radius of curvature of the brake contact surfaces 70A, 70B is the same as the radius of curvature of the contacted surfaces 72A, 72B. As the contact area decreases, the frictional resistance in the reverse direction Dd imparted from the brake housing 34 can be reduced as the brake shoe 58 attempts to move in the brake rotation direction Dc along with the motor shaft 14. Further, the brake shoe 58 is easily and firmly engaged in the brake rotation direction Dc, and the motor shaft 14 is easily braked by the brake shoe 58.

The brake shoe 58 includes a1 st brake contact surface 70A that contacts the brake housing 34 first and a2 nd brake contact surface 70B that contacts the brake housing 34 later. The advantages thereof will be explained next.

Consider here the 1 st braking stage (see fig. 5) in which only the 1 st braking abutment surface 70A of the brake shoe 58 abuts the brake housing 34. At this time, the contact area between the brake housing 34 and the brake shoe 58 can be reduced as compared with the case where the 2 nd brake contact surface 70B also contacts the brake housing 34. Therefore, in the 1 st braking stage, the frictional resistance in the reverse direction Dd applied from the brake housing 34 can be reduced. Further, the brake shoe 58 is easily firmly inserted between the brake housing 34 and the motor shaft 14 in the brake rotation direction Dc.

Then, a2 nd braking stage (refer to fig. 6) in which both the 1 st braking abutment surface 70A and the 2 nd braking abutment surface 70B abut against the brake housing 34 is considered. In this case, the contact area with the brake housing 34 can be made larger than in the 1 st braking stage. This can suppress the rattling of the brake shoe 58, and the motor shaft 14 can be stably braked by the brake shoe 58.

The non-braking contact surface 74 has a shape capable of surface-contacting the brake housing 34 during non-braking. Thus, the brake shoe 58 is less likely to be inclined around a virtual line parallel to the axial direction during non-braking, as compared with a case where the brake abutment surface 70A in a convex curved surface shape is brought into abutment with the contacted surface 72B of the flat brake housing 34. The term "when not braking" herein means: when the pressing mechanism 60 moves the brake shoe 58 in the retreat direction Db2, or when the pressing mechanism 60 holds the brake shoe 58 in the brake release position Pb. This can avoid the brake shoe 58 from contacting the motor shaft 14 due to the brake shoe 58 tilting during non-braking.

In particular, the non-braking abutment surfaces 74 are provided on the pair of clamped portions 68A, 68B, respectively. Thus, in a state where the pressing mechanism 60 holds the brake shoe 58 at the brake release position Pb, the brake shoe 58 can be brought into surface contact with the brake housing 34 at two locations on both sides in the circumferential direction. Further, the brake shoe 58 can be effectively prevented from tilting.

The brake shoe 58 is coupled to the pressing member 76 so as to be movable in the circumferential direction with respect to the pressing member 76. Thereby, the brake shoe 58 can be allowed to move in the circumferential direction so as to be sandwiched between the brake housing 34 and the motor shaft 14. At the same time, a stronger mechanical structure can be achieved than in the case where the brake shoe 58 is not coupled to the pressing member 76.

(embodiment 2)

Refer to fig. 8 and 9. In the pressing mechanism 60 according to embodiment 1, the pressing member 76 is coupled to the brake shoe 58 to move the brake shoe 58 from the braking position Pa to the braking release position Pb. In contrast, the pressing member 76 of the present embodiment is not connected to the brake shoe 58. The pressing mechanism 60 of the present embodiment includes biasing members 100A and 100B that bias the brake shoe 58 in the retreat direction Db2 in order to move the brake shoe 58 from the braking position Pa to the braking release position Pb.

The biasing members 100A and 100B of the present embodiment are tension springs and bias the brake shoe 58 with an elastic restoring force based on elastic deformation. The tension springs (i.e., biasing members 100A, 100B) couple the brake housing 34 and the brake shoe 58. The urging members 100A, 100B include: a1 st force application member 100A corresponding to the 1 st wedge-shaped space 56A; and a2 nd urging member 100B corresponding to the 2 nd wedge-shaped space 56B. The 1 st biasing member 100A can bias the brake shoe 58 in the retreat direction Db2 and on the side (clockwise in the drawing) where the interval of the 1 st wedge space 56A is wide. The 2 nd biasing member 100B can bias the brake shoe 58 in the retreat direction Db2 toward a side (counterclockwise in the drawing) where the interval of the 2 nd wedge space 56B is wide.

Next, the operation of the motor device 10 will be described. Refer to fig. 9. The operation of the brake 18 for braking the rotation of the motor shaft 14 is the same as that of embodiment 1. When braking the motor shaft 14, the clamped portion 68A of the brake shoe 58 located on the brake rotation direction Dc side is clamped between the brake housing 34 and the motor shaft 14 in the wedge-shaped space 56A in which the clamped portion 68A is arranged.

Next, an operation when the brake 18 releases the brake on the motor shaft 14 will be described. At this time, the pressing mechanism 60 drives the pressing member 76 of the pressing mechanism 60 in the retraction direction Db2, as in embodiment 1. In the present embodiment, since the brake shoe 58 is not coupled to the pressing member 76, only the pressing member 76 moves in the retraction direction Db2, and the pressing of the brake shoe 58 by the pressing member 76 is released. Thus, the brake shoe 58 can be moved in the retreat direction Db2 by the biasing member 100A corresponding to the wedge-shaped space 56A in which the brake shoe 58 is sandwiched. At this time, the biasing member 100A can move the brake shoe 58 in the retreat direction Db2 and on the side (clockwise in fig. 9) where the interval between the wedge-shaped spaces 56A into which the brake shoe 58 is inserted is wide. As a result, the brake shoe 58 can be moved from the braking position Pa to the braking release position Pb.

According to the motor device 10, since the constituent elements described in the above (a) and (B) are provided, the effects corresponding to the description can be obtained.

In addition, since the pressing member 76 is not coupled to the brake shoe 58, components necessary for coupling the pressing member 76 and the brake shoe 58 can be omitted. Further, a wide space can be secured between the pressing member 76 and the brake shoe 58.

Here, an example in which the urging members 100A and 100B are elastic members such as springs is explained. Specific examples of the urging members 100A and 100B are not particularly limited. The urging members 100A and 100B may be magnets, for example. This assumes that the brake shoe 58 is biased by the magnetic force of the magnet.

Refer to fig. 10. In embodiment 1, an example in which the outer peripheral surface of the motor shaft 14 is circular and the braking surface 66 of the brake shoe 58 is arcuate has been described. In contrast, the concave-convex structure 102 that meshes with each other is formed on the outer peripheral surface of the motor shaft 14 and the braking surface 66 of the brake shoe 58 in the present embodiment. The concave-convex structure 102 has concave portions and convex portions alternately arranged in the circumferential direction. As a result, a stronger braking force can be applied to the motor shaft 14 by the brake shoe 58.

(embodiment 3)

Refer to fig. 11. The motor device 10 of the present embodiment is different from that of embodiment 1 in the structure of the pressing mechanism 60. The non-electric drive portion 78 and the electric drive portion 80 of the pressing mechanism 60 of the present embodiment are disposed at different positions from each other. This will be described in detail later. The electric drive unit 80 is accommodated in a mechanism accommodating portion 110 provided at a different position from the accommodating recess portion 54 of the brake case 34. The direction orthogonal to the advancing/retreating direction Db and the axial direction X of the pressing member 76 is referred to as an orthogonal direction De. At this time, the electric drive unit 80 is disposed at a position shifted from the brake shoe 58 in the orthogonal direction De. The non-electric drive portion 78 is accommodated in the accommodation recess 54 as in embodiment 1.

In embodiment 1, an example in which the pressing member 76 is the rod 84 of the electric driving unit 80 is described. The pressing member 76 of the present embodiment is a2 nd link member 116 of the link mechanism 112 different from the lever 84. This will be described in detail later.

The lever 84 is coupled to the brake shoe 58 via a linkage 112. The link mechanism 112 includes: a1 st link member 114 coupled to the lever 84; and a2 nd link member 116 coupled to the brake shoe 58. One end of the 1 st link member 114 is rotatably fixed to the brake housing 34 via a fixing pin 118. The other end portion of the 1 st link member 114 is rotatably coupled to the lever 84 via a1 st coupling pin 120. One end portion of the 2 nd link member 116 is rotatably coupled to the intermediate portion of the 1 st link member 114 via a2 nd coupling pin 122. The other end portion of the 2 nd link member 116 is rotatably coupled to the brake shoe 58 via a 3 rd coupling pin 124.

The 2 nd link member 116 constitutes the urging member 76. The compression spring constituting the non-electric drive portion 78 couples the brake housing 34 and the 2 nd link member 116.

When the coil 86 of the electric drive unit 80 is energized, the electric drive unit 80 applies the 2 nd driving force Fb in the retracting direction Db2 to the pressing member 76 via the link mechanism 112. As a result, in this state, as in embodiment 1, the pressing member 76 moves in the retracting direction Db2 based on the 2 nd driving force Fb against the 1 st driving force Fa of the non-electric driving unit 78. On the other hand, when the electric drive unit 80 is in the non-energized state, the pressing member 76 is moved in the advancing direction b1 by the 1 st driving force Fa of the non-electric drive unit 78, as in embodiment 1.

According to the motor device 10, since the constituent elements described in the above (a) and (B) are provided, the effects corresponding to the description can be obtained.

In addition, by disposing the electric drive portion 80 at a location different from the accommodation recess 54, the outer diameter dimension of the entire brake housing 34 can be reduced.

(embodiment 4)

Refer to fig. 12 and 13. The motor device 10 of the present embodiment is different from that of embodiment 1 in that the pressing member 76 and the brake shoe 58 have different structures. The pressing member 76 of the present embodiment is provided separately from the rod 84 and attached to the end of the rod 84 on the side of the advancing direction Db 1.

The brake shoe 58 is formed of rollers 130A, 130B. The rollers 130A, 130B (brake shoes 58) include: a1 st roller 130A disposed in the 1 st wedge-shaped space 56A so as to be rotatable; and a2 nd roller 130B disposed in the 2 nd wedge-shaped space 56B so as to be rotatable. The rollers 130A, 130B are cylindrical bodies extending in the axial direction X.

Next, the operation of the motor device 10 will be described. First, an operation when the brake 18 brakes the rotation of the motor shaft 14 will be described. Refer to fig. 13. When braking the rotation of the motor shaft 14, the pressing mechanism 60 moves the pressing member 76 in the advancing direction Db1, and presses the rollers 130A and 130B toward the outer periphery of the motor shaft 14 via the pressing member 76. When the brake shoe 58 is pressed toward the outer periphery of the motor shaft 14, the 1 st roller 130A located on the brake rotation direction Dc side moves toward the brake rotation direction Dc in accordance with the rotation of the motor shaft 14. At this time, the 1 st roller 130A moves toward the side where the interval becomes narrower (counterclockwise in the drawing) in the 1 st wedge space 56A. The movement of the 1 st roller 130A toward the side where the gap is widened in the wedge-shaped space 56A is restricted by the pressing member 76. As a result, the 1 st roller 130A is interposed between the motor shaft 14 and the brake housing 34 in the 1 st wedge space 56A. The rotation of the motor shaft 14 can be braked by the 1 st roller 130A.

On the other hand, the 2 nd roller 130B located on the reverse rotation direction Dd attempts to move in the braking rotation direction Dc in accordance with the rotation of the motor shaft 14. At this time, the 2 nd roller 130B attempts to move toward the side (counterclockwise direction in the drawing) where the interval is widened in the 2 nd wedge space 56B. The movement of the 2 nd roller 130B is restricted by the pressing member 76. As a result, the 2 nd roller 130B continues to rotate in the 2 nd wedge-shaped space 56B without being sandwiched between the motor shaft 14 and the brake housing 34.

Next, the operation when the brake 18 releases the brake on the motor shaft 14 will be described. Refer to fig. 12. When the brake on the motor shaft 14 is released, the pressing mechanism 60 moves the pressing member 76 in the retraction direction Db 2. This releases the pressing of the rollers 130A and 130B by the pressing member 76. As a result, the rollers 130A and 130B are allowed to move toward the side where the gap is widened in the wedge spaces 56A and 56B. Thus, even when the rollers 130A and 130B are intended to move with the rotation of the motor shaft 14, the rollers can move toward the side where the gap is widened in the wedge-shaped spaces 56A and 56B, and thus the occurrence of braking of the rotation of the motor shaft 14 can be avoided. As a result, the braking of the motor shaft 14 by the rollers 130A and 130B can be released.

According to the motor device 10, since the constituent elements described in the above (a) and (B) are provided, the effects corresponding to the description can be obtained.

Next, another modification of each constituent element will be described.

The use of the motor device 10 is not particularly limited. The motor device 10 can be used for an automatic transport vehicle such as an AGV, in addition to the industrial robot 12, for example. When the motor device 10 is used for the industrial robot 12, it may be used for other industrial robots 12 than the cooperative robot. Specific examples of the driven member to which the rotational power of the motor device 10 is transmitted are not particularly limited.

In the motor apparatus 10, the reduction gear 22 is not essential. That is, the motor shaft 14 may directly transmit the rotational power to the driven member.

A specific example of the speed reducing mechanism 38 used in the speed reducing device 22 is not particularly limited. The reduction mechanism 38 may be a flexural-engagement type reduction mechanism, and may be an eccentric oscillating type reduction mechanism, a planetary gear mechanism, an orthogonal-axis gear mechanism, a parallel-axis gear mechanism, or the like. When the deflection-engagement type speed reducing mechanism is used, a specific example thereof is not particularly limited. In addition to the cylinder-type deflection-engagement type speed reducing mechanism, for example, a cup-type or top-hat-type deflection-engagement type speed reducing mechanism may be employed. The output member 42 of the reduction gear 22 may be the housing 40 in addition to the wheel carrier 48.

The position of the stopper 18 is not particularly limited. For example, the brake 18 may be disposed on the opposite side of the output from the motor 16.

Specific examples of the pressing mechanism 60 are not particularly limited. For example, the 2 nd driving direction Da2 of the electric driving unit 80 may be the forward direction Db1, and the 1 st driving direction Da1 of the non-electric driving unit 78 may be the retreat direction Db 2. At this time, the brake shoe 58 is kept in a state where the brake of the motor shaft 14 is released when the electric drive unit 80 is not supplied with electric power.

The shapes of the brake contact surfaces 70A, 70B of the brake shoe 58 and the shapes of the contacted surfaces 72A, 72B of the brake housing 34 are not particularly limited. For example, the braking contact surfaces 70A and 70B and the contacted surfaces 72A and 72B may be curved surfaces having the same radius of curvature. The brake shoe 58 may not include the 1 st brake contact surface 70A and the 2 nd brake contact surface 70B that are different from each other in timing of contact with the brake housing 34. That is, when the brake shoe 58 moves in the brake rotation direction Dc along with the motor shaft 14, the brake abutment surfaces 70A, 70B of the brake shoe 58 once abut against the brake housing 34, and then it is not necessary to additionally increase the abutment portions.

The non-braking contact surface 74 of the brake shoe 58 may not be in a shape that can be in surface contact with the brake housing 34 when not braking. The non-braking contact surface 74 may be provided on only one of the pair of clamped portions 68A, 68B, and may be configured to be in surface contact with the brake housing 34 during non-braking. The non-braking contact surface 74 may be provided on the side where the interval between the wedge-shaped spaces 56A and 56B is narrowed with respect to the 1 st braking contact surface 70A, or may be provided on the side where the interval between the wedge-shaped spaces 56A and 56B is widened with respect to the 2 nd braking contact surface 70B.

A specific mechanism for coupling the brake shoe 58 to the pressing member 76 so as to be movable in the circumferential direction with respect to the pressing member 76 is not particularly limited. For example, the brake shoe 58 may be coupled to the pressing member 76 via a sliding mechanism or the like so as to be movable relative to the pressing member 76.

The above embodiments and modifications are merely examples. These technical ideas to be abstracted should not be interpreted as being limited to the contents of the embodiments and the modifications. The contents of the embodiments and the modifications can be changed in design such as changing, adding, or deleting the components. In the above-described embodiments, the contents of which the design change can be made are highlighted by the notation of "embodiment". However, content without such annotations also allows for design changes. The hatching lines shown in the cross-section of the drawings do not limit the material of the objects marked with the hatching lines.

Any combination of the above constituent elements is also effective. For example, any contents of the other embodiments may be combined with the embodiment, or any contents of the embodiment and the other modifications may be combined with the modification.

Next, specific examples thereof will be described. For example, the braking contact surfaces 70A and 70B and the non-braking contact surface 74 of the brake shoe 58 described in embodiment 1 may be applied to the brake shoe 58 described in embodiments 2 to 3, respectively. The concave-convex structure 102 described in embodiment 2 may be applied to the brake shoe 58 described in embodiments 1 and 3.

Claims (12)

1. A motor device is provided with:

a motor that rotates a motor shaft;

a brake that brakes rotation of the motor shaft; and

a brake housing that houses the brake,

the motor arrangement is characterized in that it is,

the brake is provided with:

a brake shoe; and

a pressing mechanism that presses the brake shoe toward an outer periphery of the motor shaft,

when the pressing mechanism presses the brake shoe toward the outer periphery of the motor shaft, the brake shoe moves in the rotational direction of the motor shaft in accordance with the rotation of the motor shaft, and the brake shoe is sandwiched between the motor shaft and the brake housing, thereby braking the rotation of the motor shaft.

2. The motor apparatus according to claim 1,

a wedge-shaped space is formed between the brake housing and the motor shaft,

when braking is performed, the brake shoe is clamped between the motor shaft and the brake housing in the wedge-shaped space.

3. The motor apparatus according to claim 1 or 2,

the pressing mechanism is provided with a pressing member capable of moving forward and backward relative to the motor shaft,

the brake shoe is coupled to the pressing member so as to be movable in a circumferential direction with respect to the pressing member.

4. The motor device according to any one of claims 1 to 3,

the brake shoe includes a brake contact surface that comes into contact with a contacted surface of the brake housing when braking is performed,

the brake abutting surface is in a convex curved surface shape,

the abutted surface is in a shape with a curvature radius larger than that of the curved surface of the brake abutting surface.

5. The motor apparatus according to claim 4,

the brake contact surface includes:

a first brake abutment surface that first abuts against the brake housing when the brake shoe moves in a rotational direction of the motor shaft in accordance with rotation of the motor shaft; and

and a2 nd braking abutment surface which abuts against the brake housing after the 1 st braking abutment surface abuts against the brake housing.

6. The motor apparatus according to claim 4 or 5,

the brake shoe has a non-braking contact surface which is contacted with the brake shell when the brake is not applied,

the non-braking contact surface has a shape capable of coming into surface contact with the brake case when not braking.

7. Motor device according to claim 6, characterized in that

The brake shoe is provided with:

a1 st clamped portion that is clamped between the motor shaft and the brake housing when the brake shoe moves toward one side in a circumferential direction; and

a2 nd sandwiched portion that sandwiches between the motor shaft and the brake housing when the brake shoe moves toward the other side in the circumferential direction,

the non-braking contact surfaces are respectively arranged on the 1 st clamped part and the 2 nd clamped part.

8. Motor device according to claim 5, characterized in that

The brake shoe has a non-braking contact surface which is contacted with the brake shell when the brake is not applied,

the non-braking abutment surface is provided between the 1 st braking abutment surface and the 2 nd braking abutment surface, and is shaped to be able to come into surface contact with the brake housing when not braking.

9. The motor apparatus according to any one of claims 1, 2, and 4 to 8,

the pressing mechanism includes:

a pressing member that is movable forward and backward with respect to the motor shaft and that is movable in a forward direction to press the brake shoe toward an outer periphery of the motor shaft; and

a biasing member that biases the brake shoe in a retraction direction of the pressing member,

the pressing member is not coupled to the brake shoe.

10. The motor apparatus according to any one of claims 1, 2, and 4 to 8,

the brake shoe is composed of a roller.

11. The motor apparatus according to any one of claims 1 to 10,

further comprises a speed reduction device for reducing the speed of the rotation of the motor shaft,

the brake is disposed between the motor and the reduction gear.

12. The motor apparatus according to any one of claims 1 to 11,

the motor device is assembled to a joint portion of an industrial robot.

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