ACTUATOR

Abstract

An actuator 1 comprises a motor 20 and a speed reducer 30, which are connected to each other. A heat transfer element 25, which has elasticity, is arranged between a coil end 232a of the motor 20 and a first speed reducer housing 34A of the speed reducer 30.

Description

Technical field

[0001] The present invention relates to an actuator. State of the art

[0002] An actuator containing a motor and a speed reducer is known in the prior art (see, for example, PTL 1).

[0003] With this type of actuator, heat generation from the motor is a problem. For the motor alone, a method of heat dissipation from a housing (enclosure) is generally used by providing heat dissipation fins on the housing, but there is room for improvement regarding the motor's cooling performance (heat dissipation). List of citations from patent literature

[0004] [PTL 1] Japanese Unexamined Patent Publication No. 2021-97430 Summary of the invention: Technical problem

[0005] The present invention was made taking into account the above circumstances and has the objective of improving the heat dissipation of a motor. Solution to the problem

[0006] The present invention relates to an actuator comprising a motor and a speed reducer connected to each other, wherein a heat transfer element having elasticity is arranged between a coil end of the motor and a speed reducer housing of the speed reducer. Advantageous effects of the invention

[0007] According to the present invention, it is possible to improve the heat dissipation of the engine. Brief description of the drawings Fig. Figure 1 is a cross-sectional view showing an actuator according to a first embodiment. Fig. Figure 2 is an enlarged view of a motor's periphery in Fig. 1. Fig. Figure 3 is a cross-sectional view showing an actuator according to a second embodiment. Description of embodiments

[0008] Embodiments of the present invention are described in detail below with reference to the drawings. <Erste Ausführungsform>

[0009] Fig. Figure 1 is a cross-sectional view showing an actuator 1 according to a first embodiment of the present invention, and Fig. Figure 2 is an enlarged view of a periphery of a motor 20 in Fig. 1.

[0010] As in Fig. As shown in Figure 1, the actuator 1 according to the first embodiment comprises the motor 20, a speed reducer 30, a brake 40 and a circuit section 50. The use of the actuator 1 is not particularly restricted, but the actuator 1 can, for example, be integrated into a joint section of an industrial robot, a collaborative robot or a service robot.

[0011] In the following description, a direction along a central axis Ax of actuator 1 is referred to as an "axial direction," a direction perpendicular to the central axis Ax is referred to as a "radial direction," and a direction of rotation about the central axis Ax is referred to as a "circumferential direction." Furthermore, in the axial direction, a side connected to a driven element (not shown) (left side in the drawing) is referred to as a "driven side (load side)," and a side opposite the driven side (right side in the drawing) is referred to as a "counter-driven side (counter-load side)." [Engine configuration]

[0012] The motor 20 includes a rotating shaft 21, a motor rotor 22, a motor stator 23 and a motor housing 24.

[0013] The rotary shaft 21 extends from the speed reducer 30 to the brake 40 in such a way that it penetrates one of its centers and is rotatably mounted about the central axis Ax.

[0014] The motor rotor 22 is attached to an outer circumferential surface of the rotating shaft 21 and rotates integrally with the rotating shaft 21. The motor rotor 22 has a permanent magnet, such as a neodymium magnet, on its outer circumferential surface.

[0015] The motor stator 23 is configured by winding a coil around a stator core 231, for example, made of laminated steel plates. The motor stator 23 is arranged concentrically on an outer circumferential side of the motor rotor 22. Coil ends 232, at which the coil wound around the stator core 231 is exposed, project axially from both sides of the motor stator 23. The entire coil end 232 is formed with resin.

[0016] Elastic heat transfer elements 25 are inserted between a coil end 232a on the output side and a first speed reducer housing 34A of the speed reducer 30, and between a coil end 232b on the opposite output side and a cover element 61. A contact state of the heat transfer element 25 is described in detail below.

[0017] The motor housing 24 covers the outer circumferential surface of the motor rotor 22 and the motor stator 23, and the motor stator 23 is fitted into an inner circumferential surface of the motor housing 24. Furthermore, although not particularly restricted, the motor housing 24 is made of aluminum, primarily for the purposes of weight reduction and improved cooling performance.

[0018] The type of motor 20 is not particularly restricted, and motor 20 can, for example, be an induction motor instead of a permanent magnet type. [Configuration of speed reducer]

[0019] The speed reducer 30 is an eccentrically oscillating speed reducer of the center-crank type and is arranged on the output side of the motor 20. In particular, the speed reducer 30 comprises several (two) eccentric bodies 31a and 31b, external gears 32A and 32B, a first to a third output shaft 33A to 33C, the first speed reducer housing 34A and a second speed reducer housing 34B.

[0020] The eccentric bodies 31a and 31b are provided on the outer circumferential surface of the rotary shaft 21. In the present embodiment, the rotary shaft 21 serves both as an output shaft of the motor and as a drive shaft of the speed reducer, but the output shaft of the motor and the drive shaft of the speed reducer can be separate and connected to each other.

[0021] The external gears 32A and 32B have several internal pin holes spaced apart circumferentially at positions offset from the central axis Ax, and a central through-hole into which the rotating shaft 21 is inserted. The external gears 32A and 32B are rotatably mounted relative to the eccentric bodies 31a and 31b by eccentric body bearings 35a and 35b, which are arranged between the external gears 32A and 32B and the eccentric bodies 31a and 31b, and oscillate with the rotation of the eccentric bodies 31a and 31b.

[0022] The first output shaft 33A is located on the outer circumferential side of the rotary shaft 21 and on the output side of the external gears 32A and 32B. The second output shaft 33B is located on the output side of the first output shaft 33A, and the third output shaft 33C is located on the output side of the second output shaft 33B. The first to third output shafts 33A to 33C are connected to each other and are attached to a driven element (for example, an arm element on a tip end of a robot) (not shown). The first output shaft 33A rotatably supports the rotary shaft 21 via a bearing 36 located between the first output shaft 33A and the rotary shaft 21. The first output shaft 33A contains several internal pins 33p, which are shaped to bulge outwards towards the opposite output side in a pin-like form. The inner pin 33p is inserted into the inner pin holes of the outer gears 32A and 32B.A retaining plate 38, which limits the movement of the outer gear 32A towards the reverse output side, is arranged on the reverse output side of the inner pin 33p. In addition, an inner roller is rotatably mounted on the inner pin 33p to facilitate sliding with the inner pin hole of the outer gear 32, and the retaining plate 38 also limits the movement of the inner roller towards the reverse output side.

[0023] As in Fig. As shown in Figure 2, the retaining plate 38 comprises a disk section 38a arranged perpendicular to the axial direction, a tubular section 38b extending from an inner circumferential end of the disk section 38a to the reverse output side, and an extension section 38c extending from an end of the tubular section 38b on the reverse output side to the inner circumferential side. An outer circumference of the disk section 38a is held (or fitted) in the first speed reducer housing 34A, and a surface of the disk section 38a on the reverse output side is substantially flush with a surface of the first speed reducer housing 34A. The tubular section 38b has a tapered shape, with a gradually decreasing diameter from the output side to the reverse output side.The extension section 38c has an outer diameter larger than the outer diameter of an adjusting element 39a and an inner diameter smaller than the outer diameter of the adjusting element 39a. The adjusting element 39a is fitted to the outer circumferential surface of the rotary shaft 21 on a side section of the eccentric body bearing 35a on the output side and limits movement of the eccentric body bearing 35a to the output side. A first retaining ring 39b, fitted into a circumferential groove of the rotary shaft 21, is arranged on a side section of the adjusting element 39a on the output side. A second retaining ring 39c, fitted into the circumferential groove of the rotary shaft 21, is arranged on an axially opposite side of the first retaining ring 39b across the extension section 38c.

[0024] The tubular section 38b and the extension section 38c of the retaining plate 38, the regulating element 39a, the first retaining ring 39b, the second retaining ring 39c, and the rotating shaft 21 form a labyrinth seal. Accordingly, compared to a case where an oil seal is provided in this section, the motor 20 and the speed reducer 30 can be adequately sealed with a compact and low-loss configuration, and lubricant leakage from the speed reducer 30 can be suppressed.

[0025] As in Fig. As shown in Figure 1, the first speed reducer housing 34A is arranged on the outer circumferential side of the outer gears 32A and 32B and the retaining plate 38. An internal gear 34g is provided on an inner circumferential section of the first speed reducer housing 34A. The internal gear 34g has several external pins that serve as internal teeth and engages internally with the outer gears 32A and 32B.

[0026] The second speed reducer housing 34B is located on the outer circumference of the first output shaft 33A and the second output shaft 33B. The second speed reducer housing 34B rotatably supports the first output shaft 33A via a main bearing 37, which is located between the second speed reducer housing 34B and the first output shaft 33A. The second speed reducer housing 34B is attached to the first speed reducer housing 34A. Furthermore, the second speed reducer housing 34B is attached to a mating element E (for example, an arm element on a base end of a robot).

[0027] With this configuration, in the speed reducer 30, the eccentric bodies 31a and 31b rotate within the outer gears 32A and 32B in conjunction with the rotation of the drive shaft 21, which is driven by the motor 20, causing the outer gears 32A and 32B to oscillate at different phases. Due to the oscillation, the outer teeth of the outer gears 32A and 32B furthest from the central axis Ax engage with the inner gear 34g, and the engagement position changes with the circumferential oscillation. Specifically, the engagement position between the inner gear 34g and the outer gears 32A and 32B completes one revolution in the circumferential direction each time the drive shaft 21 rotates.There is a difference in the number of teeth between the external gears 32A and 32B and the internal gear 34g. Each time the gear in contact with the internal gear 34g completes one revolution, the external gears 32A and 32B rotate by this difference in the number of teeth. This rotation is transmitted via the internal pin 33p to the first to third output shafts 33A to 33C. Consequently, the rotational movement of the rotating shaft 21 is slowed, and the rotating shaft 21 is pulled out of the driven element connected to the third output shaft 33C. [Brake configuration]

[0028] The brake 40 is arranged on the opposite output side of the motor 20. The brake 40 of the present embodiment is a holding brake that keeps the rotating shaft 21 in a stopped state, although this is not particularly restricted.

[0029] The brake 40 includes a hub element 41, a rotor 42, an armature 43, an electromagnetic coil 44, a plate 46, a frame 47 and a brake housing 48.

[0030] The hub element 41 is attached to the rotating shaft 21 (for example, connected by a key), which extends from the motor 20 to an inner surface of the brake 40, and the rotor 42 is formed in the shape of a disc and is connected to the hub element 41 by a key or the like. Therefore, the rotor 42 rotates integrally with the rotating shaft 21.

[0031] The armature 43 is arranged on the output side of the rotor 42 and is mounted so that it is axially displaceable, allowing it to come into contact with and separate from the rotor 42. The plate 46, on the opposite output side of the rotor 42, is mounted by the frame 47. Two friction materials (linings) 43a and 46a are attached to surfaces of the armature 43 and the plate 46 that face the rotor 42 in the axial direction. One of these, located on the armature 43, is a movable friction material 43a, and the other, located on the plate 46, is a fixed friction material 46a.

[0032] The electromagnetic coil 44 moves the armature 43 in the axial direction by means of a magnetic force generated by energizing and brings the movable friction material 43a into contact with and away from the rotor 42.

[0033] The frame 47 is supported by the brake housing 48 and holds the electromagnetic coil 44, the plate 46 and the like.

[0034] The brake housing 48 is attached to the cover element 61.

[0035] The cover element 61 is arranged between the brake 40 and the motor 20. A bearing 62, which rotatably supports the rotating shaft 21, and an oil seal 63, which seals a space between the motor 20 and the brake 40, are arranged in an inner circumferential section of the cover element 61. The cover element 61, together with the brake housing 48, the motor housing 24, and the first speed reducer housing 34A, is secured by a locking screw 64.

[0036] In the brake 40 with the configuration described above, a braking force (holding force) is exerted on the rotating shaft 21 by clamping the rotor 42 between the armature 43 and the plate 46 via the friction materials 43a and 46a through the reaction of the electromagnetic coil 44. Conversely, the force clamping the rotor 42 between the armature 43 and the plate 46 is released by the reaction of the electromagnetic coil 44, thereby releasing the braking force (holding force) acting on the rotating shaft 21.

[0037] The brake 40 of the present embodiment is a brake of the non-excitation type, which is actuated by a preload force of a spring (not shown) when the electromagnetic coil 44 is not energized, and presses the rotor 42 with the armature 43 to keep the rotating shaft 21 in a stopped state. [Configuration of circuit section]

[0038] Circuit section 50 is located on the output side of the brake 40. Circuit section 50 includes a rotation detection unit 51, which detects the rotation of the rotating shaft 21, as well as a motor drive board on which a drive circuit for the motor 20 is mounted, and an encoder board on which a detection circuit for the rotation detection unit 51 is mounted. These are housed in a circuit section enclosure 52, which is attached to the brake housing 48. [Contact state of heat transfer element]

[0039] As in Fig. As shown in Figure 2, the elastic heat transfer element 25 is inserted axially between the coil end 232 of the motor 20 and an adjacent element on its outer surface. Specifically, a heat transfer element 25a is arranged between the coil end 232a on the output side and the first speed reducer housing 34A of the speed reducer 30, and a second heat transfer element 25b is arranged between the coil end 232b on the opposite output side and the cover element 61.

[0040] Furthermore, in particular, since each coil end 232 is formed with resin, each heat transfer element 25 is arranged (clamped) between the resin-formed coil end 232 (i.e., a molding resin for forming the coil end 232) and the first speed reducer housing 34A or the cover element 61.

[0041] Furthermore, each heat transfer element 25 between the coil end 232 and the first speed reducer housing 34A or the cover element 61 is compressed (a state in which an axial dimension is reduced) compared to its pre-assembly state (when the heat transfer element 25 is installed between the coil end 232 and the first speed reducer housing 34A or the cover element 61). That is, the axial dimension between the coil end 232 and the first speed reducer housing 34A or the cover element 61 is smaller (shorter) than the axial dimension of the heat transfer element 25 before assembly.

[0042] The first heat transfer element 25a on the output side is in contact with the first speed reducer housing 34A of the speed reducer 30 and is also in contact with the retaining plate 38 on its inner circumferential side. It should be noted that it is preferred that the axial compression (force) of the first heat transfer element 25a between the coil end 232a and the retaining plate 38 is weaker than the axial compression (force) of the first heat transfer element 25a between the coil end 232a and the first speed reducer housing 34A. In other words, with respect to the space in which the first heat transfer element 25a is installed, it is preferred that the axial dimension between the coil end 232a and the retaining plate 38 is larger (longer) than the axial dimension between the coil end 232a and the first speed reducer housing 34A.

[0043] Furthermore, it is preferred that the first heat transfer element 25a on the output side has a higher heat transfer performance than the second heat transfer element 25b on the counter-output side. For this purpose, an element with a higher thermal conductivity than that of the second heat transfer element 25b can be used as the first heat transfer element 25a, or the axial compression of the first heat transfer element 25a can be made greater than the axial compression of the second heat transfer element 25b.

[0044] The heat transfer element 25 is not particularly restricted, provided it exhibits elasticity and a thermal conductivity higher than that of air (approximately 0.025 W / m·K). For example, various highly thermally conductive resins can be suitable. For instance, if the heat transfer element 25 is made of epoxy or silicone resin, a thermal conductivity of 0.5 to 5.5 W / m·K can be achieved. Accordingly, heat dissipation can be improved compared to a case where a gap (air) is provided between the coil end 232 and the first speed reducer housing 34A or the cover element 61. The shape of the heat transfer element 25 is not particularly restricted. For example, a sheet shape, a gel shape, or other shapes can be used.Furthermore, the heat transfer element 25 can be applied to the coil end 232, attached to the coil end 232, or simply arranged on the coil end 232.

[0045] By providing such a heat transfer element 25, heat generated by the motor stator 23 is transferred through the motor housing 24 to the first speed reducer housing 34A or the cover element 61, and simultaneously with this transfer, heat from each coil end 232 is transferred through each heat transfer element 25 to the first speed reducer housing 34A or the cover element 61. Therefore, the heat dissipation of the motor 20 (motor stator 23), in particular the heat dissipation of the coil end 232, can be improved.

[0046] Since each heat transfer element has 25 elasticity, the retaining plate 38 and the cover element 61 can be held without applying excessive load, and strict dimensional control is not required. [Technical effects of first embodiment]

[0047] As described above, with the actuator 1 of the first embodiment, the first heat transfer element 25a, which has elasticity, is arranged between the coil end 232a of the motor 20 and the first speed reducer housing 34A of the speed reducer 30.

[0048] Accordingly, heat generated at the coil end 232a is transferred via the first heat transfer element 25a to the first speed reducer housing 34A. Therefore, in contrast to the prior art where heat dissipation was carried out by the motor alone, the heat dissipation of the motor 20 can be suitably improved by the actuator 1.

[0049] Since the heat transfer element 25 has elasticity, the heat transfer element 25 can also be easily installed without the need for strict dimensional control.

[0050] Furthermore, with the actuator 1 of the first embodiment, since the first speed reducer housing 34A is connected to the counter element E (via the second speed reducer housing 34B), the heat generated by the coil end 232a is transferred to the counter element E via the first speed reducer housing 34A.

[0051] Accordingly, the heat dissipation of the motor 20 can be further improved.

[0052] Furthermore, with the actuator 1 of the first embodiment, the first heat transfer element 25a is clamped between the coil end 232a and the first speed reducer housing 34A in a compressed state (a state in which the axial dimension is reduced) compared to a state before assembly.

[0053] Accordingly, the effect of heat transfer from the coil end 232a to the first speed reducer housing 34A can be further improved via the first heat transfer element 25a.

[0054] Furthermore, the actuator 1 of the first embodiment is in contact with the first heat transfer element 25a with the first speed reducer housing 34A and the retaining plate 38, which is arranged on the inner circumferential side of the first speed reducer housing 34A and which limits the outer gear 32A (reduction element) in the axial direction.

[0055] Accordingly, the heat generated by the coil end 232a can be transferred to the first speed reducer housing 34A, while the first heat transfer element 25a holds the retaining plate 38 securely.

[0056] Furthermore, with the actuator 1 of the first embodiment, the axial compression of the first heat transfer element 25a between the coil end 232a and the retaining plate 38 is weaker than the axial compression of the first heat transfer element 25a between the coil end 232a and the first speed reducer housing 34A.

[0057] Accordingly, the retaining plate 38 can be kept inexpensive, while the heat transfer performance of the first heat transfer element 25a to the first speed reducer housing 34A is relatively improved.

[0058] Furthermore, with the actuator 1 of the first embodiment, the second heat transfer element 25b, which has elasticity, is arranged between the coil end 232b on the reverse output side and the cover element 61, which is arranged on the reverse output side of the motor 20.

[0059] Accordingly, heat can be dissipated from the coil end 232b on the counter-output side to the cover element 61, thereby further improving the heat dissipation of the motor 20.

[0060] Furthermore, with actuator 1 of the first embodiment, the first heat transfer element 25a on the output side has a higher heat transfer performance than the second heat transfer element 25b on the counter-output side.

[0061] Accordingly, the heat transfer performance can be improved with respect to the output side, to which the counter element E is connected, i.e. the side with a larger heat capacity, and thus the heat dissipation of the motor 20 can be further improved. <Zweite Ausführungsform>

[0062] A second embodiment of the present invention is described below.

[0063] Fig. Figure 3 is a cross-sectional view showing an actuator 2 according to the second embodiment.

[0064] Actuator 2 differs from actuator 1 of the first embodiment in that actuator 2 includes a bending-engagement speed reducer 70 instead of the eccentrically oscillating speed reducer 30 of the first embodiment. These differences are mainly described below, and components that are the same as those in the first embodiment are designated with the same reference numerals, and their descriptions are omitted.

[0065] As in Fig.As shown in Figure 3, the speed reducer 70 is a cylindrical bending-engage speed reducer and is arranged on the output side of the motor 20. In particular, the speed reducer 70 comprises a shaft generator 71, an external gear 72, a first internal gear 73G, a second internal gear 74G, a first speed reducer housing 73A, a second speed reducer housing 73B and an internal gear element 74.

[0066] The shaft generator 71 is provided on a section of the rotating shaft 21 which extends into the speed reducer 70 and has a non-circular shape (for example an elliptical shape) in a cross-section perpendicular to the central axis Ax.

[0067] The outer gear 72 is a flexible cylindrical element centered on the central axis Ax and has teeth on its outer circumference. The outer gear 72 is rotatable relative to the shaft generator 71 by means of a shaft generator bearing 71B, which is arranged between the outer gear 72 and the shaft generator 71, and is flexibly deformed by the rotation of the shaft generator 71.

[0068] The first internal gear 73G and the second internal gear 74G rotate around the periphery of the shaft generator 71 about the central axis Ax. The first internal gear 73G and the second internal gear 74G are arranged in the axial direction and mesh with the external gear 72. The first internal gear 73G and the second internal gear 74G are configured such that internal teeth are provided at the corresponding locations on inner circumferential sections of the first speed reducer housing 73A and the internal gear element 74. The first speed reducer housing 73A covers the outer circumferential side of the external gear 72. The first speed reducer housing 73A, together with the brake housing 48, the cover element 61, and the motor housing 24, is secured by the locking screw 64. The internal gear element 74 is connected to an output element 77 located on its output side. The output element 77 supports the rotary shaft 21 via a bearing 75 so that it can rotate.The output element 77 is connected to a driven element (not shown).

[0069] The second speed reducer housing 73B is located on the output side of the first speed reducer housing 73A and is connected to the first speed reducer housing 73A. The second speed reducer housing 73B covers the outer circumferential side of the internal gear element 74 and rotatably supports the internal gear element 74 via a main bearing 76B (for example, a crossed roller bearing). The second speed reducer housing 73B, together with the first speed reducer housing 73A, is attached to the mating element E.

[0070] A retaining plate 78, which limits the movement of the outer gear 72 and the shaft generator bearing 71B to the opposite output side, is arranged on the opposite output side of the outer gear 72 and the shaft generator bearing 71B.

[0071] The retaining plate 78 is configured in the same way as the retaining plate 38 of the first embodiment and comprises a disk section 78a arranged perpendicular to the axial direction, a tubular section 78b extending from an inner circumferential end of the disk section 78a to the reverse output side, and an extension section 78c extending from an end of the tubular section 78b on the reverse output side to the inner circumferential side. An outer circumference of the disk section 78a is held (or fitted) in the first speed reducer housing 73A, and a surface of the disk section 78a on the reverse output side is substantially flush with a surface of the first speed reducer housing 73A. The tubular section 78b has a tapered shape, with a gradually decreasing diameter from the output side to the reverse output side.The extension section 78c has an outer diameter larger than the outer diameter of a stepped section 21a of the rotating shaft 21 and an inner diameter smaller than the outer diameter of the stepped section 21a. The stepped section 21a of the rotating shaft 21 is arranged on the inner circumferential side of the tubular section 78b and is formed in a stepped shape such that the outer diameter decreases towards the output side. A retaining ring 79, which fits into the circumferential groove of the rotating shaft 21, is arranged over the extension section 78c on an axially opposite side of the stepped section 21a.

[0072] The tubular section 78b and the extension section 78c of the retaining plate 78, the stepped section 21a of the rotating shaft 21, and the retaining ring 79 form a labyrinth seal. Accordingly, compared to a case where an oil seal is provided in this section, the motor 20 and the speed reducer 70 can be adequately sealed with a compact and low-loss configuration, and lubricant leakage from the speed reducer 70 can be suppressed.

[0073] With this configuration, the shaft generator 71, which is integrally formed with the rotating shaft 21, rotates in conjunction with the rotation of the rotating shaft 21, which is driven by the motor 20, and the motion is transmitted to the external gear 72. In this case, the external gear 72 is limited to a shape that conforms to the outer circumferential surface of the shaft generator 71 and is bent into an elliptical shape when viewed in the axial direction. Furthermore, the external gear 72 engages with the first internal gear 73G, which is attached to the main shaft section. Therefore, the external gear 72 does not rotate at the same speed as the shaft generator 71, and the shaft generator 71 rotates relative to the external gear 72. In accordance with this relative rotation, the external gear 72 is flexibly deformed so that the main shaft position and the secondary shaft position move in the circumferential direction.One period of deformation is proportional to one rotation period of the shaft generator 71.

[0074] When the external gear 72 is flexibly deformed, its main axis position changes, thus altering the position at which the external gear 72 and the first internal gear 73G mesh in the direction of rotation. This causes the external gear 72 to rotate, reducing its speed by a reduction ratio equal to the difference in the number of teeth between the external gear 72 and the first internal gear 73G. For example, if the external gear 72 has 100 teeth and the first internal gear 73G has 102 teeth, the speed will be reduced to 1 / 50. Meanwhile, the outer gear 72 also engages with the second inner gear 74G, so that the position at which the outer gear 72 and the second inner gear 74G engage with each other also changes in the direction of rotation due to the rotation of the shaft generator 71.If the number of teeth of the second internal gear 74G is the same as the number of teeth of the external gear 72, the external gear 72 and the second internal gear 74G do not rotate relative to each other, and the rotational motion of the external gear 72 is transmitted to the second internal gear 74G with a reduction ratio of 1:1. As a result, the rotational motion of the shaft generator 71 is slowed down and transmitted to the internal gear element 74 and the output element 77, and this rotational motion is then transferred to the driven element.

[0075] Furthermore, in the actuator 2 of the second embodiment, the first heat transfer element 25a, which is arranged at the coil end 232a of the motor 20, is in contact with the first speed reducer housing 73A and the mounting plate 78, instead of being in contact with the first speed reducer housing 34A and the mounting plate 38 in the first embodiment. As in the first embodiment, the mounting plate 78 is held in place while the heat generated by the coil end 232a is transferred to the first speed reducer housing 73A.

[0076] The actuator 2 of the second embodiment, which is configured as described above, can also achieve the same effects as those of the first embodiment. <sonstiges>

[0077] The embodiments of the present invention have been described above, but the present invention is not limited to the embodiments described above.

[0078] For example, in the embodiments described above, an eccentrically oscillating speed reducer of the center-crank type or a cylindrical bending-engage speed reducer is illustrated as the speed reducer. However, the type of speed reducer according to the present invention is not particularly limited and can, for example, be a bending-engage speed reducer of the pot type or cylinder hat type, an eccentrically oscillating speed reducer of the sorting type, or a simple speed reducer of the planetary type, and it can also be a speed reducer with a parallel shaft or a vertical speed reducer.

[0079] Furthermore, the details described in the embodiments described above can be suitably modified without deviating from the core of the invention. Industrial applicability

[0080] As described above, the present invention is useful for improving the heat dissipation of the engine. Reference symbol list 1, 2 Actuator 20 engine 21 Rotary shaft 23 Motor stator 24 Motor housings 25 Heat transfer element 25a first heat transfer element 25b second heat transfer element 30 speed reducers 32A, 32B External gear (gear element) 33p inner pin 34A first speed reducer housing 34B second speed reducer housing 38 Mounting plate 40 brake 50 Circuit section 61 Cover element 62 warehouses 63 Oil seal 70 Speed ​​reducers 71B Shaft generator bearing 72 External gear (gear element) 73A first speed reducer housing 73B second speed reducer housing 78 Mounting plate 231 Stator core 232, 232a, 232b Coil end Ax central axis E Counter element QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2021-97430

[0004] < / sonstiges>

Claims

[1] Actuator, comprising: a motor and a speed reducer connected to each other, wherein a heat transfer element, which has elasticity, is arranged between a coil end of the motor and a speed reducer housing of the speed reducer. [2] Actuator according to claim 1, wherein the speed reducer housing is connected to a counter element. [3] Actuator according to claim 1 or 2, wherein the heat transfer element is clamped between the coil end and the speed reducer housing in a compressed state compared to a state prior to assembly. [4] Actuator according to any one of claims 1 to 3, wherein the speed reducer includes a retaining plate which is arranged inside the speed reducer housing and limits the axial movement of a gear element, and the heat transfer element is in contact with the speed reducer housing and the mounting plate. [5] Actuator according to claim 4, wherein compression of the heat transfer element between the coil end and the retaining plate is weaker than compression of the heat transfer element between the coil end and the speed reducer housing. [6] Actuator according to any one of claims 1 to 5, the coil end is formed with resin, and the heat transfer element is clamped between the resin used to shape the coil end and the speed reducer housing. [7] Actuator according to any one of claims 1 to 6, wherein the motor contains another coil end on a side opposite a speed reducer side, and another heat transfer element, which has elasticity, is arranged between the other coil end and a cover element, which is arranged on a speed reducer opposite side with respect to the coil end. [8] Actuator according to claim 7, wherein the heat transfer element has a higher heat transfer performance than the other heat transfer element.

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