JP2022008449A - Power unit and robot having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wave gear reducer unit which can be combined with a motor compactly, while securing the degree of freedom in design.

SOLUTION: A wave gear reducer unit includes a casing, an internal gear, an external gear, a cam, and a flexible bearing. The cam is positioned radially inside of a portion where external teeth are provided. The motor has: a motor casing in which a rotor and a stator are stored; and also a motor bearing positioned between the motor casing and the rotor, and for supporting the rotor so as to rotate with respect to the motor casing. The rotor includes: a cylinder part extending along an axial direction of a central axis, and for surrounding the stator; and a rotor side connection part which is positioned on the other side in the axial direction, and at least a part of which is connected to a cam side connection part of the cam of the wave gear reducer unit. The motor bearing is arranged between an outer peripheral surface of the cylinder part and an inner peripheral surface of the motor casing.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a strain wave gearing speed reducer unit and a power unit including the same.

Conventionally, reduction gears having various configurations have been known as reduction gears that decelerate and output the rotation of the rotation shaft of an electric motor. For example, Patent Document 1 discloses a speed reducer using a strain wave gearing mechanism. This strain wave gearing reducer has an elliptical wave generator, a flexible flexspline, and a circular spline. The flexspline is in contact with each other via a bearing located on the outer periphery of the wave generator, and has a circular shape having spline-shaped teeth on the outer periphery. The circular spline has spline-shaped teeth having a larger number of teeth than the flexspline in a ring shape, and meshes with and fits on the outer periphery of the flexspline.

In the above-mentioned wave gear reduction mechanism, for example, when an input shaft is connected to the wave generator, the circular spline is fixed, and the flexspline is connected to the output shaft, when the wave generator makes one clockwise rotation, the said The flexspline rotates counterclockwise by the difference in the number of teeth from the circular spline. On the other hand, when the flexspline is fixed and the circular spline is connected to the output shaft, the circular spline rotates by the difference in the number of teeth from the flexspline.

As described above, in the above-mentioned strain wave gearing reducer, the rotation input to the wave generator is decelerated by the difference in the number of teeth between the circular spline and the flexspline, and is output from the flexspline or the circular spline.

FIG. 1 of Patent Document 1 discloses a configuration in which a strain wave gearing reducer is connected to a rotating shaft of a drive motor. In the configuration of FIG. 1, the weight of the entire device becomes heavy, and the size of the entire device becomes large and the length becomes long due to the coupling portion connecting the strain wave gearing reducer to the rotating shaft. Therefore, in the configuration disclosed in Patent Document 1, the reduction gear and the drive motor are integrated to make the entire device compact. Specifically, in the configuration disclosed in Patent Document 1, the rotor of the drive motor and the wave generator of the speed reducer are integrally formed.

Jitsukaisho 60-166261

By the way, as disclosed in Patent Document 1 described above, when the speed reducer and the drive motor (motor) are integrated, it is necessary to individually design a dedicated speed reducer and a motor. Therefore, it is necessary to design the speed reducer and the motor each time according to the required motor output, reduction ratio, etc., which poses a problem in terms of versatility.

On the other hand, as shown in FIG. 1 of Patent Document 1 described above, when a separate motor and a speed reducer are combined, the versatility of the speed reducer can be ensured, but as described in Patent Document 1 described above. The size of the device obtained by combining the speed reducer and the motor is increased.

An object of the present invention is to realize a configuration in which a strain wave gearing reducer unit can be compactly combined with a motor while ensuring a degree of freedom in design.

The wave gear reducer unit according to an embodiment of the present invention is rotatably connected to the rotor with respect to a motor having a rotor rotating about a central axis and a stator facing the rotor. Wave gear reducer unit. This wave gear reducer unit is located in a tubular casing extending along the axial direction of the central axis and inward in the radial direction of the casing so as to be rotatable relative to the casing, and is inward on the inner peripheral side. An annular internal gear having teeth and a flexible one located inward in the radial direction of the internal gear and having an external tooth that is fixed to the casing on one side in the axial direction and meshes with the internal tooth on the outer peripheral side. An annular external gear, an elliptical cam located radially inward of the external gear and connected to the other side of the rotor in the axial direction and rotating with the rotor, and the outer. Located between the tooth gear and the cam, the external gear and the cam are rotatably supported, and the external gear is radially out of the radial direction in response to the rotation of the cam that rotates with the rotor. It is provided with a flexible bearing that can be deformed in a direction. The cam has a cam-side connecting portion to which the other side of the rotor in the axial direction can be connected to one side of the cam in the axial direction, and is the other side of the external gear in the axial direction and said. It is located radially inward of the portion of the external gear where the external tooth is provided.

A power unit according to an embodiment of the present invention includes a rotor that rotates about a central axis, a motor having a stator facing the rotor, and a wave gear reducer unit. The rotor is located on the other side of the cylinder portion extending along the axial direction of the central axis and surrounding the stator and the other side of the axial direction, and at least a part thereof is the cam of the wave gear reducer unit. It has a rotor side connection portion connected to a cam side connection portion.

According to the strain wave gearing speed reducer unit according to the embodiment of the present invention, it is possible to obtain a strain wave gearing speed reducer unit having a configuration that can be compactly combined with a motor while ensuring design freedom.

FIG. 1 is a cross-sectional view showing a schematic configuration of a power unit according to the first embodiment. FIG. 2 is a cross-sectional view showing a schematic configuration of the motor unit. FIG. 3 is a cross-sectional view showing a schematic configuration of a strain wave gearing speed reducer unit. FIG. 4 is a view of the external gear, the internal gear, and the cam as viewed from one side in the axial direction. FIG. 5 is an enlarged cross-sectional view showing a connection portion between the motor unit and the strain wave gearing reducer unit in the power unit according to the second embodiment. FIG. 6 is an enlarged cross-sectional view showing a connection portion between the motor unit and the strain wave gearing reducer unit in the power unit according to the third embodiment. FIG. 7 is a view of the connection portion between the protruding portion of the rotary cylinder portion of the motor unit and the cam of the strain wave gearing speed reducer unit as viewed from the axial direction. FIG. 8 is an enlarged cross-sectional view showing a connection portion between the motor unit and the strain wave gearing reducer unit in the power unit according to the fourth embodiment. FIG. 9 is an enlarged cross-sectional view showing a connection portion between the motor unit and the strain wave gearing reducer unit in the power unit according to the fifth embodiment. FIG. 10 is an enlarged cross-sectional view showing a connection portion between the motor unit and the strain wave gearing reducer unit in the power unit according to the sixth embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated. Further, the dimensions of the constituent members in each drawing do not faithfully represent the dimensions of the actual constituent members and the dimensional ratio of each constituent member.

In the following description, the direction parallel to the central axis of the rotation axis of the motor unit is the "axis direction" or the "height direction", the direction orthogonal to the central axis is the "radial direction", and the central axis is the center. The directions along the arcs are referred to as "circumferential directions". However, the above "parallel direction" shall include a substantially parallel direction. Further, the above-mentioned "orthogonal direction" includes a direction substantially orthogonal to each other.

Further, in the following description, "one side in the axial direction" means the motor unit side of the power unit in a direction parallel to the central axis, and "the other side in the axial direction" is parallel to the central axis. In the direction, it means the wave gear reducer unit side of the power unit.

<Embodiment 1>
(overall structure)
FIG. 1 shows a schematic configuration of a power unit 1 including a strain wave gearing speed reducer unit 2 according to the first embodiment of the present invention. The power unit 1 includes a strain wave gearing speed reducer unit 2 and a motor unit 3. The power unit 1 reduces the rotation of the rotary shaft 52, which will be described later, of the motor unit 3 by the strain wave gearing speed reducer unit 2 and outputs the speed. The power unit 1 can be used as a power source for driving wheels such as robot joints and electric wheelchairs, for example.

The strain wave gearing reducer unit 2 and the motor unit 3 are columnar, respectively. In the power unit 1, the wave gear reducer unit 2 and the motor unit 3 are superposed in the height direction (vertical direction in FIG. 1), and their outer peripheral sides are connected by a plurality of bolts 4. The power unit 1 has a columnar shape as a whole.

(Motor unit)
FIG. 2 shows a schematic configuration of the motor unit 3. The motor unit 3 is a radial gap type brushless motor. Further, the motor unit 3 is a so-called outer rotor type motor in which the rotor 60 rotates outward in the radial direction of the cylindrical stator 70.

As shown in FIGS. 1 and 2, the motor unit 3 includes a motor casing 51, a rotating shaft 52, a rotor 60, and a stator 70.

The motor casing 51 is formed in a columnar shape extending in a direction in which the central axis X extends (hereinafter, referred to as an axial direction). This central axis X coincides with the central axis of the rotating shaft 52. The motor casing 51 has a motor casing side wall 51a, a motor casing bottom portion 51b, and a flange portion 51c.

The motor casing side wall 51a has a cylindrical shape extending in the axial direction. The motor casing bottom portion 51b closes one side of the motor casing side wall 51a in the axial direction. The flange portion 51c extends radially outward from the end portion surrounding the opening on the other side of the motor casing side wall 51a in the axial direction. That is, the flange portion 51c is located on the other side of the motor casing side wall 51a in the axial direction. The flange portion 51c is fixed to the strain wave gearing speed reducer unit 2 by bolts 4, as will be described later.

The rotor 60 and the stator 70 are housed in the motor casing 51. That is, the motor casing 51 covers the rotor 60 and the stator 70. A bearing 53 (motor bearing) is arranged between the inner peripheral surface of the side wall 51a of the motor casing and the rotary cylinder portion 61 described later of the rotor 60. That is, the rotary cylinder portion 61 described later of the rotor 60 is rotatably supported by the bearing 53 with respect to the inner peripheral surface of the motor casing side wall 51a. A support member 54, which will be described later, is fixed to the inner side of the motor casing 51 of the motor casing bottom 51b so as to rotatably support the rotary shaft 52 and support the stator 70.

The stator 70 is a cylindrical member. The stator 70 has a cylindrical stator core 71 and a stator coil 72 wound around a tooth (not shown) of the stator core 71. A part of the support member 54 is connected to the inner peripheral surface of the stator core 71.

The support member 54 is fixed to the bottom portion 51b of the motor casing and supports the stator 70. Further, the rotating shaft 52 is housed inside the support member 54. Specifically, the support member 54 has a fixing portion 54a and a stator supporting portion 54b.

The fixing portion 54a has a flat plate shape and is fixed to the bottom portion 51b of the motor casing by bolts 55. The stator support portion 54b is a columnar shape extending in the axial direction from the central portion of the fixing portion 54a when viewed from the axial direction. The inner peripheral surface of the stator core 71 of the stator 70 is fixed on the outer peripheral surface of the stator support portion 54b. As a result, the stator 70 is fixed to the bottom portion 51b of the motor casing inside the motor casing 51 by the support member 54.

The support member 54 has a rotary shaft through hole 54c that penetrates the fixing portion 54a and the stator support portion 54b in the axial direction at the center thereof when viewed from the axial direction. The rotary shaft 52 is rotatably housed in the rotary shaft through hole 54c. Specifically, the bearings 56 and 57 are located between the inner peripheral surface constituting the rotary shaft through hole 54c and the rotary shaft 52. As a result, the rotary shaft 52c is rotatably supported by the bearings 56 and 57 with respect to the inner peripheral surface constituting the rotary shaft through hole 54c.

The rotor 60 has a rotary cylinder portion 61 and a rotor magnet 65.

The rotary cylinder portion 61 is a bottomed cylindrical member. The rotary cylinder portion 61 is located radially outward of the stator 70 and covers the stator 70 from the other side in the axial direction. Specifically, the rotary cylinder portion 61 has a cylinder portion 62 and a bottom portion 63 (rotor side connection portion).

The tubular portion 62 has a cylindrical shape extending in the axial direction. The tubular portion 62 is located radially outward of the stator 70. As a result, the radial outside of the stator 70 is covered by the tubular portion 62. A rotor magnet 65 is fixed on the inner peripheral surface of the tubular portion 62. That is, in the radial direction, the rotor magnet 65 is located between the cylinder portion 62 and the stator 70. The stator 70 and the rotor magnet 65 are positioned with a predetermined gap in the radial direction.

The tubular portion 62 is located at a position overlapping the flexible bearing 13 described later of the strain wave gearing speed reducer unit 2 when viewed from the axial direction.

A bearing 53 is located between the outer peripheral surface of the tubular portion 62 and the inner peripheral surface of the motor casing side wall 51a. As a result, the tubular portion 62 is rotatably supported by the bearing 53 on the side wall 51a of the motor casing.

That is, the bearing 53 is located between the motor casing 51 and the rotor 60, and rotatably supports the rotor 60 with respect to the motor casing 51. As a result, the rotor 60 of the motor unit 3 can be supported with respect to the motor casing 51 in a more accurate and rotatable manner about the central axis X. As a result, the power unit 1 with less noise and vibration can be realized.

The bottom portion 63 closes the other side of the tubular portion 62 in the axial direction. The other end of the rotating shaft 52 in the axial direction is rotatably connected to the bottom 63 together with the rotating shaft 52. As a result, the rotary cylinder portion 61 rotates together with the rotary shaft 52.

The bottom portion 63 has a first protruding portion 63a fixed to a cam 12 described later of the strain wave gearing speed reducer unit 2 by a plurality of bolts 5. The first protruding portion 63a is a columnar shape that protrudes to the other side in the axial direction at the bottom portion 63. As shown in FIG. 1, in a state where the motor unit 3 and the strain wave gearing speed reducer unit 2 are combined, the first protrusion 63a is located in the recess 12b of the cam 12 described later of the strain wave gearing speed reducer unit 2. .. The first protrusion 63a has a plurality of screw holes 63c to which the bolt 5 is fastened on the other side surface in the axial direction (see FIG. 2).

As a result, the first protruding portion 63a of the rotary cylinder portion 61 can be positioned with respect to the cam 12. Therefore, the rotating shaft 52 of the motor unit 3 and the cam 12 of the strain wave gearing speed reducer unit 2 can be positioned. The plurality of bolts 5 are arranged so as to surround the rotating shaft 52 when viewed from the axial direction.

By fixing the rotary cylinder portion 61 and the cam 12 described later of the strain wave gearing speed reducer unit 2 as described above, the rotation of the rotary cylinder portion 61 can be transmitted to the cam 12 described later of the strain wave gearing speed reducer unit 2. Moreover, the rotary cylinder portion 61 and the cam 12 can be rotated with their rotation centers aligned.

The bottom portion 63 has a second protruding portion 63b projecting to the other side in the axial direction at the central portion of the first protruding portion 63a when viewed from the axial direction. As shown in FIG. 1, the second protrusion 63b is located in the through hole 12a of the cam 12 described later of the strain wave gearing speed reducer unit 2 in a state where the motor unit 3 and the strain wave gearing speed reducer unit 2 are combined. do.

(Strain wave gear reducer unit)
FIG. 3 shows a schematic configuration of the strain wave gearing speed reducer unit 2. The strain wave gearing speed reducer unit 2 is formed in a flat shape having a larger radial dimension (horizontal direction in FIGS. 1 and 3) than the height direction (vertical direction in FIGS. 1 and 3). The wave gear reducer unit 2 causes the external gear 14 or the internal gear 15 to rotate the cam 12 by giving a wave to the external gear 14 by the cam 12 rotating together with the rotating shaft 52 of the motor unit 3. introduce.

Specifically, the strain wave gearing speed reducer unit 2 includes a casing 11, a cam 12, a flexible bearing 13, an external gear 14, an internal gear 15, and a cross roller bearing 16.

The casing 11 has a cylindrical shape extending in the direction in which the central axis X extends (hereinafter referred to as the axial direction). This central axis X coincides with the central axis X of the rotary shaft 52 of the motor unit 3 in a state where the strain wave gearing reducer unit 2 is attached to the motor unit 3. Therefore, the axial direction coincides with the axial direction of the central axis X of the motor unit 3.

The casing 11 is provided with a plurality of screw holes 11a penetrating the inside of the casing 11 in the axial direction in the circumferential direction. A bolt 4 (see FIG. 1) for connecting the motor unit 3 and the strain wave gearing speed reducer unit 2 is inserted into the screw hole 11a. As will be described later, the screw hole 11a is connected to the through hole 14d of the external gear 14 located on one side (motor unit 3 side) in the axial direction with respect to the casing 11 to form an insertion hole for the bolt 4. do.

The cam 12 is arranged inside the casing 11. The cam 12 is connected to the rotary cylinder portion 61 of the motor unit 3 and rotates integrally with the rotary shaft 52 connected to the rotary cylinder portion 61.

Specifically, the cam 12 is an elliptical plate-shaped member when viewed from the axial direction. The cam 12 is arranged inside the casing 11 so that its thickness direction coincides with the axial direction. The cam 12 has a through hole 12a that penetrates the cam 12 in the axial direction. As shown in FIG. 1, in a state where the motor unit 3 and the strain wave gearing speed reducer unit 2 are combined in the through hole 12a, the axial direction from the first protruding portion 63a in the rotary cylinder portion 61 of the motor unit 3 The second protruding portion 63b protruding to the other side of the is located.

As shown in FIG. 3, the cam 12 has a cam-side connecting portion 12f to which the other side of the rotor 60 in the axial direction can be connected to one side in the axial direction. That is, the cam 12 is connected to the rotor 60 by the cam side connecting portion 12f.

The cam-side connecting portion 12f has a recess 12b in the opening portion on one side in the axial direction in the through hole 12a of the cam 12. The recess 12b has, for example, a circular shape when viewed from the axial direction. The recess 12b has a recess bottom surface 12c and a recess side surface 12d. In a state where the motor unit 3 and the strain wave gearing speed reducer unit 2 are combined, the recess bottom surface 12c is located on the other side of the first protruding portion 63a of the rotary cylinder portion 61 of the motor unit 3 in the axial direction. The faces come into contact. As shown in FIG. 1, in a state where the motor unit 3 and the strain wave gearing speed reducer unit 2 are combined, the side surface of the first protruding portion 63a of the rotary cylinder portion 61 of the motor unit 3 comes into contact with the concave side surface 12d. ..

With the above configuration, the rotary cylinder portion 61 of the motor unit 3 and the cam 12 of the strain wave gearing speed reducer unit 2 can be positioned. Therefore, the motor unit 3 can be accurately positioned with respect to the cam 12 of the strain wave gearing speed reducer unit 2.

As shown in FIG. 3, the cam 12 has a plurality of bolt through holes 12e that surround the through hole 12a and penetrate the recess bottom surface 12c of the recess 12b. A bolt 5 connecting the cam 12 and the bottom portion 63 of the rotary cylinder portion 61 of the motor unit 3 penetrates through the bolt through hole 12e. The bolt 5 penetrating the bolt through hole 12e of the cam 12 is fastened to the screw hole 63c of the bottom portion 63 of the rotary cylinder portion 61 of the motor unit 3 (see FIG. 1). That is, the other side of the rotor 60 of the motor unit 3 in the axial direction is connected in a state of being housed in the recess 12b of the cam 12. As shown in FIG. 1, by connecting the cam 12 and the bottom portion 63 of the rotary cylinder portion 61 of the motor unit 3 with a bolt 5, the cam 12 rotates together with the rotating shaft 52 of the motor unit 3. Therefore, the cam 12 rotates about the central axis X when viewed from the axial direction.

As shown in FIG. 3, when viewed from the radial direction, the cam 12 is located on the other side in the axial direction of the casing 11 and in the radial direction of the portion of the external gear 14 to be described later in which the external teeth 31 are provided. Located inward. As a result, the casing 11 has a space S on one side in the axial direction with respect to the cam 12. With the strain wave gearing speed reducer unit 2 and the motor unit 3 connected to each other, the other side of the rotary cylinder portion 61 of the motor unit 3 in the axial direction is located in the space S.

Further, although not particularly shown, the cam 12 is located radially inward of the portion where the external teeth 31 are provided with respect to the external tooth gear 14 described later. As a result, when the cam 12 rotates together with the rotating shaft 52 of the motor unit 3, the external teeth 31 of the external gear 14 mesh with the internal teeth 32 of the internal gear 15 due to the rotation of the cam 12, as will be described later.

Inside the casing 11, an external gear 14 formed in a cylindrical shape with a flange and an internal gear 15 formed in an annular shape are arranged so as to surround the cam 12. That is, the external gear 14 is located radially outward of the cam 12, and the internal gear 15 is located radially outward of the external gear 14. FIG. 4 shows the positional relationship between the external gear 14, the internal gear 15, and the cam 12 when the strain wave gearing reducer unit 2 is viewed from the other side in the axial direction. In FIG. 4, the description of the casing 11 is omitted.

A flexible bearing 13 is arranged between the cam 12 and the external gear 14 when viewed from the axial direction. The flexible bearing 13 is arranged between the cam 12 and the external gear 14, and can be displaced in the radial direction of the cam 12 according to the rotation of the cam 12. As a result, when the elliptical cam 12 rotates, the end portion in the major axis direction of the cam 12 pushes the inner peripheral side of the external gear 14 radially outward through the flexible bearing 13. That is, the flexible bearing 13 is located between the external gear 14 and the cam 12, supports the external gear 14 and the cam 12 in a relative rotatable manner, and rotates the cam 12 that rotates together with the rotor 60. The external gear 14 is deformed radially outward according to the above.

As shown in FIGS. 1 and 3, the external gear 14 is a cylindrical shape with a flange made of a flexible thin plate. Specifically, the external gear 14 has a cylindrical portion 14a that covers the cam 12 from the outside in the radial direction, and a flange portion 14b that extends outward in the radial direction on one side of the cylindrical portion 14a in the axial direction. Have.

The cylindrical portion 14a has a plurality of external teeth 31 (see FIG. 4) arranged at a constant pitch in the circumferential direction on the outer peripheral surface. The external teeth 31 extend in the axial direction on the outer peripheral surface of the cylindrical portion 14a. The inner peripheral surface of the cylindrical portion 14a comes into contact with the flexible bearing 13 arranged on the outer periphery of the cam 12. As a result, the rotation of the elliptical cam 12 causes the end portion of the cam 12 in the major axis direction to be radially deformed in the cylindrical portion 14a via the flexible bearing 13. By rotating the elliptical cam 12 in this way, it is possible to give a wave motion in the radial direction to the cylindrical portion 14a of the external gear 14.

The flange portion 14b is annular when viewed from the axial direction. The flange portion 14b has a thick portion 14c on the outer peripheral side, which is thicker than the other portions of the external gear 14. The thick portion 14c has a plurality of through holes 14d penetrating in the thickness direction in the circumferential direction. The through hole 14d is connected to the screw hole 11a of the casing 11 in a state where the thick portion 14c of the external gear 14 is arranged on one side of the casing 11 in the axial direction. As shown in FIG. 1, the flange portion 14b is fixed to one side of the casing 11 in the line direction by a bolt 4 fastened to the through hole 14d and the screw hole 11a.

The length of the flange portion 14b protruding radially outward from the cylindrical portion 14a has a length that can be easily deformed when the cylindrical portion 14a is pressed by the rotation of the cam 12 as described above.

As shown in FIG. 4, the internal gear 15 is an annular member, and has a plurality of internal teeth 32 arranged at a constant pitch in the circumferential direction on the inner peripheral surface. The internal teeth 32 extend in the axial direction on the inner peripheral surface of the internal gear 15. The internal gear 15 is arranged at a position that surrounds the cam 12, the flexible bearing 13, and the cylindrical portion 14a of the external gear 14 from the outside in the radial direction. The internal gear 15 and the external gear 14 are arranged with a predetermined gap in a part in the circumferential direction. As a result, when the external gear 14 is pushed outward in the radial direction by the end of the cam 12 in the major axis direction and deformed, the internal teeth 32 of the internal gear 15 mesh with the external teeth 31 of the external gear 14. ..

As shown in FIG. 3, the connecting ring 20 is fixed to the internal gear 15 on one side in the axial direction. The connecting ring 20 is rotatably supported by the inner surface of the casing 11 via a cross roller bearing 16. The connecting ring 20 is fixed to the internal gear 15 by a plurality of bolts 6. Since the configuration of the cross roller bearing 16 is the same as the configuration of a general cross roller bearing, detailed description thereof will be omitted.

As shown in FIG. 4, the number of internal teeth 32 of the internal gear 15 is larger than the number of external teeth 31 of the external gear 14. Since the number of teeth of the external tooth 31 and the number of teeth of the internal tooth 32 are different in this way, the external tooth gear 14 is deformed in the radial direction by the rotation of the cam 12, and the external tooth 31 of the external tooth gear 14 is changed to the internal tooth gear. By sequentially meshing with the internal teeth 32 of 15, the rotational speed of the internal tooth gear 15 can be reduced with respect to the rotational speed of the cam 12.

Therefore, with the above configuration, the rotation of the rotating shaft 52 of the motor unit 3 can be decelerated by the strain wave gearing reducer unit 2 and output by the internal gear 15.

With the above configuration, the motor unit 3 and the strain wave gearing speed reducer unit 2 can be connected with their rotation centers aligned. Therefore, the strain wave gearing speed reducer unit 2 rotates in a state where the rotation center coincides with the motor unit 3. In other words, the connecting portion between the rotor 60 of the motor unit 3 and the recess 12b of the cam 12 of the strain wave gearing speed reducer unit 2 may be configured to be capable of transmitting rotation from the rotor 60 to the cam 12. Therefore, the degree of freedom in designing the strain wave gearing reducer unit 2 can be improved as compared with the case where the motor and the strain wave gearing reducer have a single configuration.

Moreover, the strain wave gearing speed reducer unit 2 has a space S on one side in the axial direction with respect to the cam 12, and the cam 12 has a recess 12b on one side in the axial direction. Then, in a state where the motor unit 3 and the strain wave gearing speed reducer unit 2 are combined, a part of the motor unit 3 is located in the space S of the strain wave gearing speed reducer unit 2, and the rotary cylinder portion 61 of the motor unit 3 A part is located in the recess 12b of the cam 12. As a result, the power unit 1 obtained by connecting the motor unit 3 and the strain wave gearing speed reducer unit 2 can be made compact in the axial direction.

Further, with the above configuration, the motor unit 3 using the outer rotor having low power consumption and large output torque can be attached to the strain wave gearing speed reducer unit 2. Therefore, the power unit 1 having low power consumption and large output torque can be obtained.

Moreover, by making the motor unit 3 an outer rotor, the rotor 60 is connected not to the rotation center of the cam 12 of the strain wave gearing speed reducer unit 2 but to the outer peripheral side in the radial direction from the rotation center. As a result, the runout of the motor unit 3 is less likely to be transmitted to the strain wave gearing speed reducer unit 2. Further, even if the rotation center of the cam 12 of the wave gear reducer unit 2 and the rotation center of the rotor 60 are eccentric due to machining accuracy or the like, the cam 12 can be formed by using the motor unit 3 as the outer rotor as described above. And the rotor 60 can be rotatably connected.

Further, the tubular portion 62 of the rotor 60 in the motor unit 3 is located at a position overlapping the flexible bearing 13 described later of the strain wave gearing speed reducer unit 2 when viewed from the axial direction. Therefore, the space S that the strain wave gearing reducer unit 2 has on one side in the axial direction of the cam 12 can be efficiently used. As a result, the motor unit 3 can be arranged more compactly with respect to the strain wave gearing reducer unit 2.

<Embodiment 2>
FIG. 5 shows an enlarged connection portion between the cam 112 of the strain wave gearing speed reducer unit 102 and the rotary cylinder portion 161 of the motor unit 103 in the power unit 101 according to the second embodiment. The power unit 101 according to the second embodiment has a structure of a connection portion between the cam 112 of the strain wave gearing speed reducer unit 102 and the rotary cylinder portion 161 of the motor unit 103, which is different from the power unit 1 of the first embodiment. Hereinafter, the same configurations as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted, and only the parts different from the configurations of the first embodiment will be described.

As shown in FIG. 5, the cam 112 of the strain wave gearing speed reducer unit 102 has a plate shape, and has a protruding portion 112a protruding to one side in the axial direction at a central portion when viewed from the axial direction. The bottom portion 163 (rotor side connection portion) of the rotary cylinder portion 161 of the motor unit 103 has a through hole 163a that fits at the protruding portion 112a of the cam 112 and the peripheral portion of the opening portion at the central portion when viewed from the axial direction. ..

The bottom portion 163 of the rotary cylinder portion 161 is fixed to the cam 112 by welding in a state of being fitted to the protruding portion 112a of the cam 112 at the peripheral edge portion of the opening portion of the through hole 163a. As a result, the cam 112 can be rotatably connected to the rotary cylinder portion 161 together with the rotary cylinder portion 161. In the present embodiment, in the cam 112, the radial outer peripheral side of the protruding portion 112a is the cam side connecting portion.

The protruding portion 112a of the cam 112 has a rotary shaft through hole 112b penetrating in the axial direction at the central portion when viewed from the axial direction. The rotary shaft 52 is fixed to the cam 112 in a state where the rotary shaft 52 of the motor unit 103 is housed in the rotary shaft through hole 112b. As a result, the cam 112 rotates together with the rotation shaft 52.

With the above configuration, even if there is a dimensional error in each component of the motor unit 103 and the strain wave gearing speed reducer unit 102, the bottom portion 163 of the rotary cylinder portion 161 of the motor unit 103 and the cam 112 of the strain wave gearing speed reducer unit 102. Can be connected to.

As a result, the bottom portion 163 of the rotary cylinder portion 161 of the motor unit 103 and the cam 112 of the strain wave gearing speed reducer unit 102 can be easily connected. Therefore, high dimensional accuracy is not required at the connection portion between the motor unit 103 and the strain wave gearing speed reducer unit 102, so that the productivity of the power unit 101 can be improved.

<Embodiment 3>
FIG. 6 shows an enlarged connection portion between the cam 212 of the strain wave gearing speed reducer unit 202 and the rotary cylinder portion 261 of the motor unit 203 in the power unit 201 according to the third embodiment. The power unit 201 according to the third embodiment has a structure of a connection portion between the cam 212 of the strain wave gearing speed reducer unit 202 and the rotary cylinder portion 261 of the motor unit 203, which is different from the power unit 1 of the first embodiment. Hereinafter, the same configurations as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted, and only the parts different from the configurations of the first embodiment will be described.

As shown in FIG. 6, the rotary cylinder portion 261 of the motor unit 203 has a gear portion 263a (rotor side connection portion) projecting to the other side in the axial direction at the bottom portion 263. The gear portion 263a projects from the bottom portion 263 to the other side in the axial direction in a columnar shape, and has a plurality of motor side tooth portions 263b arranged on the side surface at predetermined intervals.

FIG. 7 is a view of the cam 212 and the gear portion 263a as viewed from the axial direction. As shown in FIG. 7, the cam 212 of the strain wave gearing speed reducer unit 202 has a gear portion through hole 212a capable of accommodating the gear portion 263a of the bottom portion 263 of the motor unit 203. The inner surface constituting the gear portion through hole 212a has a shape along the outer surface of the gear portion 263a of the motor unit 203. That is, the gear portion through hole 212a has a gear shape when viewed from the axial direction. The cam 212 has a cam-side tooth portion 212b (cam-side connection portion) that meshes with the motor-side tooth portion 263b of the gear portion 263a of the motor unit 203 on the inner surface constituting the gear portion through hole 212a.

The bottom portion 263 of the rotary cylinder portion 261 of the motor unit 203 has a rotary shaft through hole 263c penetrating in the axial direction at the central portion when viewed from the axial direction. The rotary shaft 52 is fixed to the rotary cylinder portion 261 in a state where the rotary shaft 52 of the motor unit 203 is housed in the rotary shaft through hole 263c. As a result, the rotary shaft 52 rotates together with the rotary cylinder portion 261.

With the above configuration, the cam 212 of the strain wave gearing speed reducer unit 202 can be rotatably connected to the bottom portion 263 of the rotary cylinder portion 261 of the motor unit 203 together with the rotary cylinder portion 261.

The rotation transmission portion 280 is configured by the motor side tooth portion 263b of the rotary cylinder portion 261 of the motor unit 203 and the cam side tooth portion 212b of the cam 212 of the strain wave gearing speed reducer unit 202. That is, the power unit 201 is located at the connection portion between the other side of the rotor 260 and the cam 212 in the axial direction, is displaceable in a direction orthogonal to the central axis X, and rotates the rotor 260 with the cam 212. It has a rotation transmission unit 280 capable of transmitting to.

As a result, even if there is a dimensional error in each component of the motor unit 203 and the wave gear reducer unit 202, the gear portion 263a of the rotary cylinder portion 261 of the motor unit 203 and the cam 212 of the wave gear reducer unit 202 The dimensional error and the like can be absorbed between the gear portion through hole 212a and the gear portion through hole 212a. Therefore, by providing the above-mentioned rotation transmission unit 280, even if the rotor 260 and the cam 212 are not accurately and concentrically connected, the cam 212 responds to the rotation of the rotor 260 about the central axis X. Can be rotated.

Further, by inserting the gear portion 263a of the rotary cylinder portion 261 into the gear portion through hole 212a of the cam 212, the cam 212 and the rotary cylinder portion 261 can be easily and rotatably connected. Therefore, high dimensional accuracy is not required at the connection portion between the motor unit 203 and the strain wave gearing speed reducer unit 202, so that the productivity of the power unit 201 can be improved.

Moreover, by providing the rotation transmission unit 280 at the connection portion between the rotor 260 and the cam 212, it is possible to suppress the runout of the motor unit 203 from being transmitted to the strain wave gearing speed reducer unit 202.

<Embodiment 4>
FIG. 8 shows an enlarged connection portion between the cam 312 of the strain wave gearing speed reducer unit 302 and the rotary cylinder portion 361 of the motor unit 303 in the power unit 301 according to the fourth embodiment. The power unit 301 according to the fourth embodiment has a structure of a connection portion between the cam 312 of the strain wave gearing speed reducer unit 302 and the rotary cylinder portion 361 of the motor unit 303, which is different from the power unit 1 of the first embodiment. Hereinafter, the same configurations as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted, and only the parts different from the configurations of the first embodiment will be described.

As shown in FIG. 8, the cam 312 (cam side connection portion) of the strain wave gearing speed reducer unit 302 is connected to the bottom portion 363 (rotor) of the rotary cylinder portion 361 of the motor unit 303 via the Oldham joint 380 (rotation transmission portion). It is connected to the side connection part). The old dam joint 380 has the same configuration as a general old dam joint. Therefore, the detailed configuration of the Oldham joint 380 will be omitted.

The Oldham joint 380 is located at the connection portion between the other side of the rotor 360 and the cam 312 in the axial direction, is displaceable in a direction orthogonal to the central axis X, and rotates the rotor 360 with the cam 312. It is a rotation transmission unit that can transmit to.

With the above configuration, the rotation of the cam 312 can be transmitted to the rotary cylinder portion 361 even when the rotation centers of the cam 312 and the rotary cylinder portion 361 do not match. Therefore, the cam 312 and the rotary cylinder portion 361 can be easily and rotatably connected. Therefore, high dimensional accuracy is not required at the connection portion between the motor unit 303 and the strain wave gearing speed reducer unit 302, so that the productivity of the power unit 301 can be improved.

Moreover, by providing the Oldham joint 380 at the connection portion between the rotor 360 and the cam 312, it is possible to suppress the runout of the motor unit 303 from being transmitted to the strain wave gearing speed reducer unit 302.

<Embodiment 5>
FIG. 9 shows an enlarged connection portion between the cam 12 of the strain wave gearing speed reducer unit 2 and the rotary cylinder portion 461 of the motor unit 403 in the power unit 401 according to the fifth embodiment. The power unit 401 according to the fifth embodiment has a structure of a connection portion between the cam 12 of the strain wave gearing speed reducer unit 2 and the rotary cylinder portion 461 of the motor unit 403, which is different from the power unit 1 of the first embodiment. Hereinafter, the same configurations as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted, and only the parts different from the configurations of the first embodiment will be described.

As shown in FIG. 9, the rotary cylinder portion 461 of the motor unit 403 has a protruding portion 463a protruding to the other side in the axial direction at the bottom portion 463 (rotor side connecting portion). The protrusion 463a is housed in the rotating shaft through hole 12a of the cam 12 of the strain wave gearing reducer unit 2 in a state where the motor unit 403 and the strain wave gearing speed reducer unit 2 are combined.

The elastic deformation member 480 is located in the recess 12b (cam side connection portion) of the cam 12 of the strain wave gearing speed reducer unit 2. That is, the strain wave gearing speed reducer unit 2 has an elastic deformation member 480. The elastically deformable member 480 is formed in an annular shape by, for example, a material such as an elastically deformable resin or rubber. A bolt 5 for fastening the bottom portion 463 of the rotary cylinder portion 461 and the cam 12 penetrates the elastically deforming member 480. That is, the bottom portion 463 of the rotary cylinder portion 461 and the cam 12 are connected via the elastically deforming member 480.

The elastically deforming member 480 is located at the connection portion between the other side of the rotor 460 and the cam 12 in the axial direction, is displaceable in a direction orthogonal to the central axis X, and rotates the rotor 460 with the cam. It is a rotation transmission unit that can transmit to 12.

If each component of the motor unit and the strain wave gearing reducer unit has a dimensional error or the like, the motor unit and the strain wave gearing reducer unit may not be fastened with bolts. On the other hand, as in the present embodiment, by arranging the elastic deformation member 480 between the bottom 463 of the rotary cylinder portion 461 of the motor unit 403 and the cam 12 of the strain wave gearing speed reducer unit 2, the dimensional error and the like are described. Can be absorbed by the elastic deformation of the elastic deformation member 480. That is, even when each component of the motor unit 403 and the strain wave gearing speed reducer unit 2 has a dimensional error or the like, the rotary cylinder portion 461 and the cam 12 can be connected by the bolt 5.

Therefore, the motor unit 403 and the strain wave gearing speed reducer unit 2 can be easily connected. Therefore, high dimensional accuracy is not required at the connection portion between the motor unit 403 and the strain wave gearing speed reducer unit 2, and the productivity of the power unit 401 can be improved.

Moreover, by providing the elastic deformation member 480 at the connection portion between the rotor 460 and the cam 12, it is possible to suppress the runout of the motor unit 403 from being transmitted to the strain wave gearing speed reducer unit 2.

<Embodiment 6>
FIG. 10 shows an enlarged connection portion between the cam 512 of the strain wave gearing speed reducer unit 502 and the rotary cylinder portion 561 of the motor unit 503 in the power unit 501 according to the sixth embodiment. The power unit 501 according to the sixth embodiment has a structure of a connection portion between the cam 512 of the strain wave gearing speed reducer unit 502 and the rotary cylinder portion 561 of the motor unit 503, which is different from the power unit 1 of the first embodiment. Hereinafter, the same configurations as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted, and only the parts different from the configurations of the first embodiment will be described.

As shown in FIG. 10, the cam 512 of the strain wave gearing speed reducer unit 502 has a plate shape, and has a protruding portion 512a protruding to one side in the axial direction at a central portion when viewed from the axial direction. The bottom portion 563 (rotor side connection portion) of the rotary cylinder portion 561 of the motor unit 503 has a through hole 563a that fits at the protruding portion 512a of the cam 512 and the peripheral portion of the opening portion at the central portion when viewed from the axial direction. ..

The bottom portion 563 of the cam 512 and the rotary cylinder portion 561 has pin through holes 512b and 563b in which the pins 581 are housed, respectively. A needle roller bearing 582 is located between the inner surface constituting the pin through hole 512b (cam side connection portion) of the cam 512 and the pin 581. That is, the diameter of the pin through hole 512b is a diameter at which the pin 581 and the needle roller bearing 582 can be arranged.

As a result, the pin 581 connecting the rotary cylinder portion 561 of the motor unit 503 and the cam 512 of the strain wave gearing speed reducer unit 502 can be supported in the radial direction by the needle roller bearing 582. Therefore, even if each component of the motor unit 503 and the strain wave gearing speed reducer unit 502 has a dimensional error or the like, the pin 581 is provided to the inner surface constituting the pin through hole 512b of the cam 512 via the needle roller bearing 582. I can support it.

Moreover, according to the above configuration, the cam 512 of the strain wave gearing speed reducer unit 502 can be rotatably connected together with the rotary cylinder portion 561 of the motor unit 503 by the pin 581.

The rotation transmission unit 580 is configured by the pin 581 and the needle roller bearing 582. That is, the power unit 501 is located at the connection portion between the other side of the rotor 560 and the cam 512 in the axial direction, is displaceable in a direction orthogonal to the central axis X, and rotates the rotor 560 with the cam 512. It has a rotation transmission unit 580 capable of transmitting to.

Therefore, according to the configuration of the present embodiment, even if each component of the motor unit 503 and the strain wave gearing speed reducer unit 502 has a dimensional error or the like, the cam 512 can be rotated together with the rotary cylinder portion 561 with respect to the rotary cylinder portion 561. You can connect. Therefore, high dimensional accuracy is not required at the connection portion between the motor unit 503 and the strain wave gearing speed reducer unit 502, so that the productivity of the power unit can be improved.

Moreover, by providing the rotation transmission unit 580 at the connection portion between the rotor 560 and the cam 512, it is possible to suppress the runout of the motor unit 503 from being transmitted to the strain wave gearing speed reducer unit 502.

(Other embodiments)
Although the embodiment of the present invention has been described above, the above-described embodiment is merely an example for carrying out the present invention. Therefore, the embodiment is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented within a range that does not deviate from the gist thereof.

In each of the above embodiments, the structure of the connection portion between the rotor and the cam has been described. However, the configuration is not limited to the configuration of each of the above-described embodiments as long as the rotation of the rotor can be transmitted to the cam.

In each of the above embodiments, the motor unit is an outer rotor type motor. However, the motor unit may be an inner rotor type motor in which the rotor rotates inside the cylindrical stator.

In each of the above embodiments, the motor unit is a radial gap type motor. However, the motor unit may be a motor having another configuration such as an axial gap type motor.

The present invention can be used for a strain wave gearing reducer unit attached to a motor unit.

1, 101, 201, 301, 401, 501 Power unit 2, 102, 202, 302, 502 Wave gear reducer unit 3, 103, 203, 303, 403, 503 Motor unit 11 Casing 12, 112, 212, 312, 512 Cam 12a Rotating shaft through hole 12b Recess 12c Recess bottom surface 12d Recess side surface 12f Cam side connection 13 Flexible bearing 14 External gear 15 Internal gear 31 External tooth 32 Internal tooth 51 Motor casing 51a Motor casing Side wall 51b Motor casing bottom 52 Rotating shaft 53 Bearing (motor bearing)
60, 160, 260, 360, 460, 560 Rotor 61, 161, 261, 361, 461, 561 Rotor cylinder 62 Cylinder 63, 163, 263, 363, 463, 563 Bottom (rotor side connection)
63a 1st protrusion 63b 2nd protrusion 70 Stator 112a Protrusion 163a Through hole 212a Gear part through hole 212b Cam side tooth part (cam side connection part)
263a Gear part (rotor side connection part)
263b Motor side tooth part 280, 580 Rotation transmission part 380 Oldham joint (rotation transmission part)
480 Elastic deformation member (rotation transmission part)
512b pin through hole (cam side connection)
563b Pin through hole 581 Pin 582 Needle roller bearing X Axis S Space

The present invention relates to a power unit and a robot having the power unit.

An object of the present invention is to realize a configuration in which a power unit can be compactly combined with a motor while ensuring a degree of freedom in design.

The power unit according to the embodiment of the present invention includes a motor having a rotor rotating about a central axis, a stator facing the rotor, and a wave gear deceleration rotatably connected to the rotor. A power unit including a machine unit, wherein the wave gear reducer unit has a tubular casing extending along the axial direction of the central axis, and is arranged inward in the radial direction of the casing, and has an inner circumference. An annular internal gear having internal teeth on the side and a flexible annular external gear having external teeth that are located radially inward of the internal gear and that mesh with the internal teeth on the outer peripheral side. , An elliptical cam located radially inward of the external gear and connected to the other side of the rotor in the axial direction and rotating with the rotor, and between the external gear and the cam. A flexible bearing that supports the external gear and the cam in a relative rotatable manner and deforms the external gear radially outward in response to the rotation of the cam that rotates with the rotor. The cam has a cam-side connecting portion to which the other side of the rotor in the axial direction can be connected to one side of the cam in the axial direction, and the external gear of the external gear in the axial direction. The motor is located on the other side and radially inward of the portion of the external gear in which the external tooth is provided, and the motor includes a motor casing in which the rotor and the stator are housed, and the motor casing . It further comprises a motor bearing located between the motor casing and the rotor that rotatably supports the rotor with respect to the motor casing, the rotor being axial to the central axis. A rotor-side connection that extends along and surrounds the stator and is located on the other side in the axial direction and at least partly connected to the cam-side connection of the cam of the wave gear reducer unit. The motor bearing is arranged between the outer peripheral surface of the tubular portion and the inner peripheral surface of the motor casing .
The power unit according to the embodiment of the present invention includes a rotor having a rotor rotating about a central axis, a stator facing the rotor, and a wave gear rotatably connected to the rotor. A power unit including a speed reducer unit, wherein the wave gear speed reducer unit is arranged inside a tubular casing extending along the axial direction of the central axis and inward in the radial direction of the casing . An annular internal gear having internal teeth on the peripheral side and a flexible annular external gear having external teeth that are located radially inward of the internal gear and that mesh with the internal teeth on the outer peripheral side. An elliptical cam located inward in the radial direction of the external gear, connected to the other side of the rotor in the axial direction , and rotating with the rotor, and the external gear and the cam. Flexible that is located between the external gears and supports the external gear and the cam so as to be relatively rotatable, and deforms the external gear radially outward in response to the rotation of the cam that rotates with the rotor. The cam comprises a bearing, and the cam has a cam-side connecting portion to which the other side of the rotor in the axial direction can be connected to one side of the cam in the axial direction, and the external tooth in the axial direction. A recess located on the other side of the gear and radially inward of the portion of the external gear where the external tooth is provided , and the cam-side connecting portion is recessed toward the other side on one side in the axial direction. The rotor has a first protruding portion that protrudes to the other side in the axial direction, and a surface of the first protruding portion located on the other side in the axial direction is on the bottom surface of the recess. Contact.
The power unit according to the embodiment of the present invention includes a rotor having a rotor rotating about a central axis, a stator facing the rotor, and a wave gear rotatably connected to the rotor. A power unit including a speed reducer unit, wherein the wave gear speed reducer unit is arranged inside a tubular casing extending along the axial direction of the central axis and inward in the radial direction of the casing . An annular internal gear having internal teeth on the peripheral side and a flexible annular external gear having external teeth that are located radially inward of the internal gear and that mesh with the internal teeth on the outer peripheral side. An elliptical cam located inward in the radial direction of the external gear, connected to the other side of the rotor in the axial direction , and rotating with the rotor, and the external gear and the cam. Flexible that is located between the external gears and supports the external gear and the cam so as to be relatively rotatable, and deforms the external gear radially outward in response to the rotation of the cam that rotates with the rotor. The cam comprises a bearing, and the cam has a cam-side connecting portion to which the other side of the rotor in the axial direction can be connected to one side of the cam in the axial direction, and the external tooth in the axial direction. A recess located on the other side of the gear and radially inward of the portion of the external gear where the external tooth is provided , and the cam-side connecting portion is recessed toward the other side on one side in the axial direction. The rotor has a first protrusion that projects to the other side in the axial direction, the recess has a side surface that extends toward one side in the axial direction, and the side surface is the first. 1 Contact the side surface of the protrusion .
The power unit according to the embodiment of the present invention includes a rotor having a rotor rotating about a central axis, a stator facing the rotor, and a wave gear rotatably connected to the rotor. A power unit including a speed reducer unit, wherein the wave gear speed reducer unit is arranged inside a tubular casing extending along the axial direction of the central axis and inward in the radial direction of the casing . An annular internal gear having internal teeth on the peripheral side and a flexible annular external gear having external teeth that are located radially inward of the internal gear and that mesh with the internal teeth on the outer peripheral side. An elliptical cam located inward in the radial direction of the external gear, connected to the other side of the rotor in the axial direction , and rotating with the rotor, and the external gear and the cam. Flexible that is located between the external gears and supports the external gear and the cam so as to be relatively rotatable, and deforms the external gear radially outward in response to the rotation of the cam that rotates with the rotor. The cam comprises a bearing, and the cam has a cam-side connecting portion to which the other side of the rotor in the axial direction can be connected to one side of the cam in the axial direction, and the external tooth in the axial direction. Located on the other side of the gear and radially inward of the portion of the external gear where the external tooth is provided , the wave gear reducer unit is located on the other side of the rotor in the axial direction and said . It further has a rotation transmission unit located at a connection portion with the cam, capable of being displaced in a direction orthogonal to the central axis, and capable of transmitting the rotation of the rotor to the cam.

The robot according to the embodiment of the present invention has the above-mentioned power unit.

According to the power unit according to the embodiment of the present invention and the robot having the power unit, the power unit having a configuration that can be compactly combined with the motor while ensuring the degree of freedom in design, and the robot having the power unit. can get.

The present invention can be used for a power unit and a robot having the power unit.

Claims (8)

A wave gear reducer unit rotatably connected to a rotor having a rotor that rotates about a central axis and a stator that faces the rotor.
A cylindrical casing extending along the axial direction of the central axis,
An annular internal gear that is located radially inward of the casing and is rotatable relative to the casing and has internal teeth on the inner peripheral side.
A flexible annular external gear that is located inward in the radial direction of the internal gear and has an external tooth that is fixed to the casing on one side in the axial direction and meshes with the internal tooth on the outer peripheral side.
An elliptical cam located inward in the radial direction of the external gear, connected to the other side of the rotor in the axial direction, and rotating with the rotor.
It is located between the external gear and the cam, supports the external gear and the cam in a relative rotatable manner, and has a diameter of the external gear according to the rotation of the cam that rotates with the rotor. Flexible bearings that deform outward in the direction,
Equipped with
The cam
A cam-side connecting portion to which the other side of the rotor in the axial direction can be connected is provided on one side of the cam in the axial direction.
A strain wave gearing reducer unit located on the other side of the external gear in the axial direction and radially inward of the portion of the external gear provided with the external tooth. In the strain wave gearing speed reducer unit according to claim 1,
The cam-side connection portion is recessed toward the other side on one side in the axial direction, and has a recess in which at least a part of the other side of the rotor in the axial direction is accommodated and at least a part thereof can be connected. Has a strain wave gearing reducer unit. In the strain wave gearing speed reducer unit according to claim 2,
The recess is
With the bottom
A side surface extending from the bottom surface toward one of the axial directions,
Have,
A strain wave gearing reducer unit in which the bottom surface and the side surface are in contact with at least a part of the other side of the rotor in the axial direction. In the strain wave gearing speed reducer unit according to claim 1,
A rotation transmission unit located at a connection portion between the other side of the rotor and the cam in the axial direction, displaceable in a direction orthogonal to the central axis, and capable of transmitting the rotation of the rotor to the cam. Further has a wave gear reducer unit. In a power unit including a rotor that rotates about a central axis, a motor having a stator facing the rotor, and a wave gear reducer unit according to any one of claims 1 to 4.
The rotor is
A tubular portion that extends along the axial direction of the central axis and surrounds the stator, and
A rotor side connection portion located on the other side in the axial direction and at least a part of which is connected to the cam side connection portion of the cam of the strain wave gearing reducer unit.
Has a power unit. In the power unit according to claim 5,
The rotor-side connecting portion is a power unit having a protruding portion that protrudes from the tubular portion to the other side in the axial direction and is located in a recess provided on one side of the cam in the axial direction. In the power unit according to claim 5 or 6.
The motor is
A motor casing in which the rotor and the stator are housed, and
A motor bearing located between the motor casing and the rotor and rotatably supporting the rotor with respect to the motor casing.
Further has a power unit. In the power unit according to any one of claims 5 to 7.
The tubular portion is a power unit located at a position overlapping with the flexible bearing when viewed from the axial direction.

Images