JP2018035885A - Wave gear reducer with electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and compact constitution in a wave gear speed reducer with an electric motor.SOLUTION: A wave gear speed reducer 1 with an electric motor includes: a shaft 4 to which a stator 51 is fixed; a rotation body 11 which has a rotor 55 and a cam 12 and is penetrated by a shaft 1; an external gear 14 which surrounds the rotation body 11 and the stator 51 from the diameter direction external side of the shaft 4 and allows one side of an axial line direction to be fixed to the shaft 4; a flexible bearing 13; an internal teeth gear 15; an output part 16 which is connected to the internal teeth gear 15 and has a flat plate part 16b and a cylindrical part 16c; a first bearing 17 which is located between the shaft 4 and the cylindrical part 16c and supports the output part 16 rotatably for the shaft 4; and a second bearing 18 which is located between the cylindrical part 16c and the rotation body 11 and supports the output part 16 and the rotation body 11 relatively rotatably. The flexible bearing 13, the first bearing 17 and the second bearing 18 are arranged so as to stand in line on prescribed positions in the axial line direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wave gear reducer with an electric motor.

  2. Description of the Related Art Conventionally, speed reducers with various configurations are known as speed reducers that decelerate and output the rotation of the rotating shaft of an electric motor. For example, Patent Document 1 discloses a reduction gear using a wave gear reduction mechanism. This reduction device is in contact with an elliptical wave generator via a wave generator bearing located on the outer periphery of the wave generator, and has an elastic gear having teeth on the outer periphery, and more teeth than the number of teeth of the elastic gear. And an internal gear meshing with the elastic gear. This internal gear is fixed to the frame.

  Further, in the configuration disclosed in Patent Document 1, a rotor to which the wave generator is mounted is disposed outside the stator of the electric motor in the radial direction. The rotor is rotatably supported by bearings on both sides in the axial direction of the stator column with respect to the stator column provided with the stator. The elastic gear is connected to an output shaft. The output shaft is rotatably supported by the frame via a bearing.

  The rotation of the rotor is transmitted from the wave generator to the elastic gear. The rotation of the elastic gear is decelerated at a constant rate with respect to the rotation of the rotor according to the difference in the number of teeth between the elastic gear and the internal gear. Thereby, the rotation of the electric motor can be decelerated and output from the output shaft.

  There are various uses for the electric motor and the speed reducer. For example, as disclosed in Patent Document 2, there is a use for joint driving of a robot. In the configuration disclosed in Patent Document 2, the first arm and the second arm are relatively rotated by the electric motor and the speed reducer. Specifically, the electric motor is provided on the outer side of the first arm. Inside the first arm and the second arm, the speed reducer is disposed that decelerates the rotation of the electric motor and rotates the second arm relative to the first arm.

Japanese Utility Model Publication No. 1-133546 Japanese Patent No. 2561227

  By the way, in the case of the structure currently disclosed by the said patent document 2, as mentioned above, an electric motor (electric motor) is arrange | positioned on the outer side of a 1st arm, and a reduction gear is put on the inner side of a 1st arm and a 2nd arm. Has been placed. Therefore, the electric motor protrudes from the first arm and the second arm. As disclosed in Patent Document 2 described above, when the electric motor and the reduction gear are used for joint drive of a robot, etc., a compact configuration is required as the configuration of the electric motor and the reduction gear.

  In the configuration disclosed in Patent Document 1, the rotor is rotatably supported by bearings on both sides in the axial direction of the stator column with respect to the stator column. Therefore, in the axial direction, it is necessary to increase the length of the rotor by the amount of the bearing. Therefore, the electric motor and the speed reducer are increased in size. Moreover, in the structure currently disclosed by the said patent document 1, since the said bearing which supports the said rotor rotatably with respect to the said stator support | pillar is needed, a number of parts will increase and a structure will also become complicated.

  An object of the present invention is to realize a simple and compact configuration in a wave gear reducer with an electric motor.

  A wave gear reducer with an electric motor according to an embodiment of the present invention is an electric wave gear reducer with an electric motor that includes an electric motor having a rotor and a stator and decelerates and outputs the rotation of the rotor. The wave gear reducer with an electric motor extends in an axial direction, has a shaft to which the stator is fixed, the rotor disposed to face the stator, an elliptical outer shape, and the rotation A rotating body integrally rotating with the child, the rotating body through which the shaft passes, and the rotating body and the stator are disposed so as to surround the shaft from the outside in the radial direction, and one side in the axial direction is A flexible annular external gear that is fixed to the shaft and has external teeth at a radially outer position of the cam on the outer peripheral side, and is disposed between the external gear and the cam. A flexible bearing that supports the external gear and the cam so as to be relatively rotatable, and deforms the external gear radially outward in response to rotation of the cam accompanying rotation of the rotating body; Surrounding the external gear from the outside in the radial direction And an annular internal gear having internal teeth meshing with the external teeth on the inner peripheral side, a flat plate portion connected to the internal gear and extending in a direction intersecting the axial direction, and the axis line from the flat plate portion to the axis line A cylindrical portion extending in a direction; a first bearing positioned between the shaft and the cylindrical portion and rotatably supporting the output portion with respect to the shaft; and the cylindrical shape And a second bearing that is positioned between the rotating portion and the rotating body and supports the output portion and the rotating body so as to be relatively rotatable. The flexible bearing, the first bearing, and the second bearing are arranged side by side in a direction orthogonal to the axial direction at a predetermined position in the axial direction.

  According to the wave gear reducer with an electric motor according to an embodiment of the present invention, a simple and compact configuration can be realized.

Drawing 1 is a sectional view showing a schematic structure of a wave gear reducer with an electric motor concerning an embodiment. FIG. 2 is a diagram schematically illustrating a relationship among a cam, an external gear, and an internal gear in the wave gear reduction mechanism. FIG. 3 is a cross-sectional view showing an example in which a wave gear reducer with an electric motor is applied to joint drive of an articulated robot. FIG. 4 is a view corresponding to FIG. 1 showing a schematic configuration of a wave gear reducer with an electric motor according to another embodiment. FIG. 5 is a view corresponding to FIG. 1 showing a schematic configuration of a wave gear reducer with an electric motor according to another embodiment. FIG. 6 is a view corresponding to FIG. 3 illustrating an example in which a wave gear reducer with an electric motor according to another embodiment is applied to joint drive of an articulated robot.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same or an equivalent part in a figure, and the description is not repeated. Moreover, the dimension of the structural member in each figure does not faithfully represent the actual dimension of the structural member, the dimensional ratio of each structural member, or the like.

  In the following description, a direction parallel to the shaft is referred to as an “axial direction”, and a radial direction of the shaft (a direction orthogonal to the axial direction) is referred to as a “radial direction”. However, the “parallel direction” includes a substantially parallel direction. In addition, the above-mentioned “orthogonal direction” includes a substantially orthogonal direction.

  In the following description, “one side in the axial direction” means the motor side of the wave gear reducer with motor in a direction parallel to the shaft, and “the other side in the axial direction” is parallel to the shaft. Mean direction, it means the wave gear reducer side of the wave gear reducer with electric motor.

(overall structure)
FIG. 1 shows a schematic configuration of a wave gear reducer 1 with an electric motor according to an embodiment of the present invention. The wave gear reducer 1 with an electric motor includes a wave gear reduction mechanism 2 and an electric motor 3. The wave gear reducer 1 with the electric motor decelerates the rotation of a rotor 55 (to be described later) of the electric motor 3 by the wave gear reduction mechanism 2 and outputs it. As will be described later, the wave gear reducer 1 with an electric motor can be used as a power source for driving a joint of a robot and the like.

  The wave gear reducer 1 with an electric motor has a cylindrical shape. The wave gear reduction mechanism 2 and the electric motor 3 are arranged side by side in the axial direction on a hollow shaft 4 extending in the direction in which the axis X extends (hereinafter referred to as the axial direction). The wave gear reduction mechanism 2 and the electric motor 3 are integrally configured as will be described later.

(Electric motor)
The electric motor 3 is a radial gap type brushless motor. As shown in FIG. 1, the electric motor 3 has a flat shape in which the dimension in the radial direction (left and right direction in FIG. 1) is larger than the dimension in the axial direction.

  The electric motor 3 includes a stator 51 and a rotor 55. The stator 51 has an annular shape and is fixed on the shaft 4 by bolts 5. The rotor 55 is disposed so as to surround the stator 51 from the outside in the radial direction. That is, the rotor 55 is disposed to face the stator 51.

  The stator 51 includes a stator core 52 and a stator coil 53. The stator core 52 has a plurality of annular electromagnetic steel plates stacked in the thickness direction. The shaft 4 passes through the center of the stator core 52. The stator coil 53 is disposed in a slot (not shown) provided in the stator core 52.

  The rotor 55 includes a rotor yoke 56 and a rotor magnet 57. The rotor yoke 56 has a cylindrical shape, and the other side in the axial direction is connected to a cam 12 described later of the wave gear reduction mechanism 2. Thereby, the rotation of the rotor 55 is transmitted to the cam 12 of the wave gear reduction mechanism 2. The rotor 55 and the cam 12 constitute the rotating body 11.

  The rotor yoke 56 has an inner diameter larger than the outer diameter of the stator 51 on one side in the axial direction. The rotor yoke 56 has an inner diameter smaller than the outer diameter of the stator 51 on the other side in the axial direction. That is, the rotor yoke 56 has a large diameter portion 56a on one side in the axial direction and a small diameter portion 56b on the other side in the axial direction. The other end portion of the rotor yoke 56 in the axial direction, that is, the end portion of the small diameter portion 56b is connected to the cam 12 of the wave gear reduction mechanism 2 as described later. The rotor magnet 57 is fixed on the inner surface of the large diameter portion 56 a of the rotor yoke 56. The rotor magnet 57 is disposed on the outer side in the radial direction of the stator 51 so as to face the stator 51.

(Wave gear reduction mechanism)
As shown in FIG. 1, the wave gear reduction mechanism 2 has a flat shape in which the dimension in the radial direction (left-right direction in FIG. 1) is larger than the dimension in the axial direction (vertical direction in FIG. 1). The wave gear reduction mechanism 2 applies a wave motion to the external gear 14 by the cam 12 that rotates together with the rotor 55 of the electric motor 3, thereby reducing and transmitting the rotation of the cam 12 to the internal gear 15.

  Specifically, the wave gear reduction mechanism 2 includes a cam 12, a flexible bearing 13, an external gear 14, an internal gear 15, an output unit 16, a first bearing 17, and a second bearing 18. With.

  The cam 12 is an annular member having an elliptical outer shape when viewed from the axial direction. The cam 12 is arranged side by side with the electric motor 3 in the axial direction so that the thickness direction thereof coincides with the axial direction.

  The cam 12 has an outer diameter that is smaller than the outer diameter of the rotor 55 of the electric motor 3. Thereby, in the wave gear reduction mechanism 2, a space for disposing the flexible bearing 13 can be formed outside the cam 12 in the radial direction. Therefore, the wave gear reducer 1 with an electric motor can be made compact in the radial direction.

  The cam 12 has a through hole 12a that passes through the cam 12 in the axial direction. The end of the small diameter portion 56b of the rotor yoke 56 in the electric motor 3 is fixed on the inner peripheral surface of the through hole 12a. As a result, the cam 12 rotates integrally with the rotor 55. Note that the method of fixing the rotor yoke 56 to the cam 12 may be, for example, fitting, welding, adhesion, or bolting.

  The cam 12 and the rotor yoke 56 are disposed radially outward of the shaft 4. That is, the shaft 4 passes through the rotating body 11 constituted by the cam 12 and the rotor yoke 56. The cam 12 and the rotor yoke 56 are rotatable with respect to the shaft 4.

  A bottomed cylindrical external gear 14 and an annular internal gear 15 are disposed 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 disposed radially outward of the external gear 14. FIG. 2 is a diagram schematically showing the positional relationship between the external gear 14, the internal gear 15 and the cam 12. In FIG. 2, the description of the configuration other than the external gear 14, the internal gear 15, and the cam 12 is omitted.

  A flexible bearing 13 that supports the cam 12 and the external gear 14 so as to be relatively rotatable is disposed between the cam 12 and the external gear 14 when viewed from the axial direction. The flexible bearing 13 is disposed between the cam 12 and the external gear 14 and can be deformed in the radial direction of the cam 12 according to the rotation of the cam 12. Thus, when the elliptical cam 12 rotates, the end portion in the long axis direction of the cam 12 presses the inner peripheral side of the external gear 14 radially outward via the flexible bearing 13. .

  As shown in FIG. 1, the external gear 14 is a bottomed cylindrical member made of a flexible thin plate. Specifically, the external gear 14 includes a cylindrical portion 14a (side wall portion) that covers the cam 12 from the radially outer side, and a bottom portion that extends radially inward on one side in the axial direction of the cylindrical portion 14a. 14b.

  The cylindrical portion 14 a has a larger inner diameter than the cam 12 and the electric motor 3. In the cylindrical portion 14a, a plurality of external teeth 31 (see FIG. 2) are formed at a constant pitch in the circumferential direction at a position radially outward of the cam 12 on the outer circumferential surface (outer circumferential side). The external teeth 31 are formed on the other outer peripheral surface of the cylindrical portion 14a in the axial direction so as to extend in the axial direction. The cylindrical portion 14 a is in contact with the flexible bearing 13 whose inner peripheral surface is disposed on the outer periphery of the cam 12.

  Thereby, when the elliptical cam 12 rotates, the end portion in the major axis direction of the elliptical cam 12 causes the cylindrical portion 14 a to deform in the radial direction via the flexible bearing 13. Thus, by rotating the elliptical cam 12, it is possible to give a wave in the radial direction to the external teeth 31 of the external gear 14.

  The bottom portion 14b has an annular shape when viewed from the axial direction. As shown in FIG. 1, the shaft 4 passes through the bottom portion 14b. The annular bottom portion 14 b is fixed to the end portion on one side in the axial direction of the shaft 4 by a bolt 5 on the inner peripheral side. That is, the bottom portion 14 b is fixed to the shaft 4 on one side of the electric motor 3 in the axial direction.

  In the present embodiment, the bottom portion 14b of the external gear 14 is directly fixed to the shaft 4 by the bolt 5, but this is not a limitation, and the bottom portion 14b of the external gear 14 is interposed via another member. It may be fixed to the shaft 4.

  With the above configuration, the electric motor 3 is covered with the external gear 14. That is, the electric motor 3 is disposed in the wave gear reduction mechanism 2. Thereby, the electric motor 3 and the wave gear reduction mechanism 2 can be integrated with a compact configuration in the axial direction. In addition, the radial space of the external gear 14 can be used effectively. Therefore, the wave gear reducer 1 with a motor having a compact configuration can be obtained.

  The internal gear 15 is an annular member, and a plurality of internal teeth 32 are formed on the inner peripheral surface at a constant pitch in the circumferential direction. The internal teeth 32 are formed on the inner peripheral surface of the internal gear 15 so as to extend in the axial direction. The internal gear 15 is disposed so as to surround the cylindrical portion 14a of the cam 12, the bearing 13, and the external gear 14 from the radially outer side. The internal gear 15 is configured such that when the external gear 14 is deformed by being pressed in the radial direction by the end in the major axis direction of the elliptical cam 12, the internal teeth 32 of the internal gear 15 are external to the external gear 14. The teeth 31 mesh with each other.

  As shown in FIG. 2, 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. Thus, since the number of teeth of the external teeth 31 and the number of teeth of the internal teeth 32 are different, the rotation of the cam 12 causes the external gear 14 to be deformed in the radial direction so that the external teeth 31 of the external gear 14 are changed to the internal gear. By meshing with the 15 internal teeth 32 in order, the rotational speed of the internal gear 15 can be reduced with respect to the rotational speed of the cam 12.

  Therefore, with the above configuration, the rotation of the rotor 55 of the electric motor 3 can be decelerated by the wave gear reduction mechanism 2 and output from the internal gear 15.

  As shown in FIG. 1, an annular output portion 16 is fixed to the internal gear 15 by a bolt 6 when viewed from the axial direction. The output part 16 has a through hole 16a in the central part when viewed from the axial direction. The output portion 16 is connected to the internal gear 15 and has a flat plate portion 16b extending in a direction intersecting the axial direction, and a cylindrical portion 16c extending from the flat plate portion 16b in the axial direction. The flat plate portion 16b is annular. The outer peripheral side of the flat plate portion 16 b is connected to the internal gear 15. The cylindrical portion 16c has a cylindrical shape extending from the inner peripheral side of the flat plate portion 16b toward one side in the axial direction.

  The shaft 4 is inserted into the through hole 16 a of the output unit 16. A first bearing 17 is disposed between the inner surface of the through hole 16 a and the shaft 4, that is, between the cylindrical portion 16 c and the shaft 4. The first bearing 17 is located on the radially inner side of the output portion 16 with respect to the cylindrical portion 16c. Thereby, the output part 16 is rotatable with respect to the shaft 4. That is, the first bearing 17 supports the output unit 16 so as to be rotatable with respect to the shaft 4.

  A second bearing 18 is disposed between the radially outer side of the cylindrical portion 16 c and the radially inner side of the cam 12 and the rotor yoke 56. This 2nd bearing 18 is located in the radial direction outer side of the output part 16 with respect to the cylindrical part 16c. Thereby, the output part 16, the cam 12, and the rotor yoke 56 are relatively rotatable. That is, the cam 12 and the rotor yoke 56 are supported by the second bearing 18 so as to be rotatable with respect to the output unit 16.

  With the above configuration, the rotation of the rotor 55 of the electric motor 3 is output from the output unit 16 via the internal gear 15 after being reduced by the wave gear reduction mechanism 2.

  In the wave gear reducer 1 with an electric motor having the above-described configuration, the external gear 14 of the wave gear reduction mechanism 2 is connected to the shaft 4. Therefore, the shaft 4 and the external gear 14 do not rotate relative to each other, and the internal gear 15 rotates with respect to the shaft 4 and the external gear 14. Further, the rotor 55 of the electric motor 3 is rotatably disposed inside the external gear 14 in the radial direction. As a result, the rotor 55 and the internal gear 15 of the electric motor 3 that rotate with respect to the external gear 14 are arranged separately inward and outward in the radial direction of the external gear 14.

  With such a configuration, the number of bearings can be reduced as compared with a configuration in which rotation is output via an external gear. Therefore, with the configuration of the present embodiment, the number of parts of the wave gear reducer 1 with an electric motor can be reduced and the configuration can be simplified.

  Moreover, with the above-described configuration, in the wave gear reducer 1 with an electric motor according to the present embodiment, the flexible bearing 13, the first bearing 17, and the second bearing 18 are orthogonal to the axial direction at predetermined positions in the axial direction. It is arranged side by side in the direction. That is, the flexible bearing 13, the first bearing 17, and the second bearing 18 are arranged side by side in the radial direction.

  Thereby, the several bearing of the wave gear reducer 1 with an electric motor can be collectively arrange | positioned in the predetermined position of the said axial direction. Therefore, the structure of the wave gear reducer 1 with an electric motor can be made compact in the axial direction.

  Moreover, in the wave gear reducer 1 with an electric motor according to the present embodiment, the external gear 14 is fixed to the shaft 4 on one side of the electric motor 3 in the axial direction, and the flexible bearing 13 and the first bearing 17. The second bearing 18 is disposed on the other side of the electric motor 3 in the axial direction.

  Thereby, the components of the electric motor 3 and the wave gear reduction mechanism 2 can be arranged without generating a useless space in the axial direction. Therefore, the wave gear reducer 1 with an electric motor can be made more compact in the axial direction.

(Articulated robot)
Next, an example when the wave gear reducer 1 with an electric motor having the above-described configuration is used for joint driving of the multi-joint robot 100 will be described. FIG. 3 shows an example in which the wave gear reducer 1 with an electric motor according to the present embodiment is applied to the joint drive of the articulated robot 100. Here, the articulated robot means a robot having a plurality of connection portions (joints) in which the arms are connected to each other.

  The articulated robot 100 includes a first arm 70 and a second arm 80. The first arm 70 and the second arm 80 are connected so as to be relatively rotatable.

  Specifically, the main shaft 90 passes through the first arm 70 and the second arm 80. The main shaft 90 is fixed to the second arm 80, and is rotatably supported by the bearing 71 with respect to the first arm 70. The main shaft 90 has a flange portion 91 at one end. The flange portion 91 is fixed on the outer surface of the second arm 80 by a bolt 92. Thereby, the main shaft 90 connects the first arm 70 and the second arm 80 so as to be relatively rotatable at a connection portion between the first arm 70 and the second arm.

  A wave gear reducer 1 with an electric motor is fixed on the main shaft 90 in the second arm 80. Specifically, the wave gear reducer 1 with an electric motor is disposed in the second arm 80, and the main shaft 90 passes through the shaft 4 of the wave gear reducer 1 with an electric motor. The shaft 4 of the wave gear reducer 1 with the electric motor is fixed to the flange portion 91 and the second arm 80 of the main shaft 90 by bolts 92.

  As described above, by making the shaft 4 of the wave gear reducer 1 with an electric motor a hollow shaft through which the main shaft 90 can penetrate, the wave gear reducer 1 with an electric motor can be fixed to the main shaft 90. . Therefore, the wave gear reducer 1 with the electric motor can be disposed inside the joint structure in the multi-joint robot 100 and used for joint driving.

  The second arm 80 has an opening 81 at a connection portion with the first arm 70. In this opening 81, a part of the output part 16 of the wave gear reducer 1 with an electric motor arranged in the second arm 80 is exposed. The first arm 70 is connected to the output portion 16 exposed at the opening 81 of the second arm 80 by a bolt 72. A bearing 82 is disposed between the first arm 70 and the peripheral edge of the opening 81 in the second arm 80.

  With the above configuration, the rotation of the electric motor 3 of the wave gear reducer 1 with the electric motor is decelerated by the wave gear reduction mechanism 2 and output from the output unit 16, and then transmitted to the first arm 70 connected to the output unit 16. Is done. Since the wave gear reducer 1 with the electric motor is fixed to the second arm 80, the first arm 70 rotates with respect to the second arm 80. The first arm 70 and the second arm 80 are rotatable relative to each other by a bearing 82, and the main shaft 90 is rotatably supported by a bearing 71 with respect to the first arm 70. Therefore, as described above, the first arm 70 rotates with respect to the second arm 80 by the rotation output from the output unit 16 of the wave gear reducer 1 with electric motor.

  As described above, by using the wave gear reducer 1 with an electric motor according to the present embodiment for joint driving of the articulated robot 100, the mechanism for driving the joint of the articulated robot 100 has a compact configuration compared to the conventional configuration. can do. That is, since the wave gear reducer 1 with an electric motor according to the present embodiment has a compact configuration in the axial direction as described above, it can be compactly arranged in the second arm 80 in the axial direction of the main shaft 90. . Therefore, a compact configuration in which the electric motor 3 or the like does not protrude at the joint portion of the multi-joint robot 100 can be realized.

  Further, by integrating the electric motor and the wave gear reducer as in the present embodiment, it can be easily incorporated into the joint portion of the articulated robot 100.

  Further, in the above configuration, the wave gear reducer 1 with the motor is not attached to the arm as in the conventional configuration, but is fixed to the main shaft 90 and the output unit 16 is connected to the first arm 70. Therefore, the wave gear reducer 1 with an electric motor can be applied to various configurations without being affected by the shape of the arm (cylindrical shape, plate shape, etc.). In other words, the wave gear reducer 1 with an electric motor can be attached as a drive unit inside the joint portion of the articulated robot 100 without changing the structure of the robot body.

(Other embodiments)
While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented without departing from the spirit of the invention.

  In the said embodiment, the wave gear reducer 1 with an electric motor is cylindrical. However, the wave gear reducer with an electric motor may have any shape as long as the rotation of the rotor 55 of the electric motor 3 can be reduced by the wave gear reduction mechanism 2 and output from the output unit 16. .

  In the embodiment, the wave gear reducer 1 with an electric motor is used for joint drive of the articulated robot 100. However, you may use the wave gear reducer 1 with an electric motor as other drive units, such as a drive device of a wheelchair.

  In the above-described embodiment, the electric motor 3 of the wave gear reducer 1 with the electric motor includes the stator 51 fixed on the shaft 4 and the rotor 55 disposed so as to be rotatable radially outward of the stator 51. . That is, the electric motor 3 according to the embodiment is a so-called outer rotor type motor in which the rotor 51 is positioned radially outward of the stator 55.

  However, the electric motor of the wave gear reducer with an electric motor may be a so-called inner rotor type motor in which the rotor is positioned radially inward of the stator. FIG. 4 shows an example of a wave gear reducer 101 with an electric motor that uses an inner rotor type motor as the electric motor 103. In the following description, the same components as those in the above-described embodiment are denoted by the same reference numerals, description thereof will be omitted, and only portions different from those in the above-described embodiment will be described.

  In the wave gear reducer 101 with an electric motor shown in FIG. 4, the hollow shaft 104 has a stator support 104 a at one end in the axial direction. The stator support portion 104a includes a disc portion 104b extending radially outward from the shaft 104, and a cylindrical portion 104c extending from the disc portion 104b toward the other side in the axial direction. The disk portion 104 b is provided integrally with the shaft 104. That is, the stator support portion 104 a is provided integrally with the shaft 104. The cylindrical portion 104c has an inner diameter that can accommodate the stator 151 and the rotor 155 inward.

  A stator 151 is fixed on the inner peripheral surface of the cylindrical portion 104c. The stator 151 has an annular stator core 152 when viewed from the axial direction. The stator core 152 has an inner diameter that can accommodate the rotor 155 inward. A stator coil 153 is arranged in a slot (not shown) of the stator core 152.

  A rotor 155 is disposed inside the stator 151. In the radial direction of the shaft 104, the rotor 155 is disposed between the stator 151 and the shaft 104. The rotor 155 includes a cylindrical rotor yoke 156 and a rotor magnet 157 fixed on the outer peripheral surface of the rotor yoke 156. The rotor magnet 157 is disposed to face the stator 151. The rotor yoke 156 has an outer diameter on the other side in the axial direction larger than an outer diameter on one side in the axial direction, and an inner diameter on the other side in the axial direction is larger than an inner diameter on the one side in the axial direction. The other side of the rotor yoke 156 in the axial direction is connected to the cam 112.

  Even if the electric motor 103 is an outer rotor type motor as described above, the same effects as those of the present embodiment can be obtained.

  In the said embodiment, the electric motor 3 of the wave gear reducer 1 with an electric motor is a radial gap type motor. However, the electric motor of the wave gear reducer with an electric motor may be an axial gap type motor. FIG. 5 shows an example of a wave gear reducer 201 with an electric motor that uses an axial gap type motor as the electric motor 203. In the following description, the same components as those in the above-described embodiment are denoted by the same reference numerals, description thereof will be omitted, and only portions different from those in the above-described embodiment will be described.

  The electric motor 203 includes a stator 251 fixed on the shaft 4 and a rotor 255 connected to the cam 212. The stator 251 and the rotor 255 are arranged side by side in the axial direction of the shaft 4. Specifically, the stator 251 is disposed on one side in the axial direction, and the rotor 255 is disposed on the other side in the axial direction. That is, in the axial direction, the rotor 255 is disposed between the stator 251 and the wave gear reduction mechanism 2.

  The stator 251 includes a stator core 252 and a stator coil (not shown). The stator 251 is fixed to the shaft 4 and the external gear 14 by bolts 5. The rotor 255 includes a rotor magnet 257. The rotor magnet 257 has an annular shape when viewed from the axial direction, and is connected to the cam 212 of the wave gear reduction mechanism 2.

  Even if the electric motor 203 is an axial gap type motor as described above, the same effects as those of the present embodiment can be obtained. In addition, by using the axial gap type motor as described above as the electric motor 203, in the radial direction of the shaft 4, the size of the wave gear reducer 201 with the electric motor is set to be the same as that of the above-described embodiment. It can be made smaller than one dimension. Therefore, the wave gear reducer 201 with an electric motor having a compact configuration in the radial direction is obtained.

  FIG. 6 shows an example in which the wave gear reducer 201 with an electric motor having the axial gap type electric motor 203 as described above is used for joint driving of the articulated robot 200. Also in the following description regarding FIG. 6, the same components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

  The articulated robot 200 includes a first arm 270 and a second arm 280. The 1st arm 270 and the 2nd arm 280 are connected so that relative rotation is possible. The first arm 270 and the second arm 280 are connected so that their longitudinal ends overlap each other. That is, the first arm 270 and the second arm 280 are in the connected state, and the longitudinal directions of both are the same.

  The wave gear reducer 201 with the electric motor is disposed inside the connection portion (joint portion) between the first arm 270 and the second arm 280. A main shaft 290 that passes through the first arm 270 and the second arm 280 passes through the shaft 4 of the wave gear reducer 201 with electric motor at the connecting portion. The main shaft 290 is fixed to the second arm 280 and connects the first arm 270 and the second arm 280 so as to be relatively rotatable. The shaft 4 is fixed to the second arm 280 and the main shaft 290 in the second arm 280.

  The output unit 16 of the wave gear reducer 201 with the electric motor is fixed to the first arm 270 with a bolt 272.

  With the above configuration, the rotation of the rotor 255 of the electric motor 203 is transmitted to the first arm 270 via the output unit 16 after being decelerated by the wave gear reducer 2. As described above, since the shaft 4 of the wave gear reducer 201 with the electric motor is fixed to the second arm 280, the first arm 270 rotates with respect to the second arm 280.

  The present invention can be used for a wave gear reducer with an electric motor in which an electric motor and a wave gear reducer are integrally formed.

DESCRIPTION OF SYMBOLS 1, 101, 201 Wave gear reducer with electric motor 2 Wave gear reduction mechanism 3, 103, 203 Electric motor 4, 104 Shaft 11 Rotating body 12 Cam 12a Through-hole 13 Flexible bearing 14 External gear 15 Internal gear 16 Output part 16b Flat plate portion 16c Cylindrical portion 17 First bearing 18 Second bearing 31 External teeth 51, 151, 251 Stator 55, 155, 255 Rotor 70 First arm 80 Second arm 90 Main shaft 100, 200 Articulated robot

Claims (7)

A wave gear reducer with an electric motor comprising an electric motor having a rotor and a stator, which decelerates and outputs the rotation of the rotor,
A shaft extending in the axial direction and having the stator fixed thereto;
A rotor disposed opposite to the stator; a rotating body having an elliptical outer shape and a cam that rotates integrally with the rotor; and the shaft passes through the rotor;
The rotating body and the stator are arranged so as to surround the shaft from the outside in the radial direction, and one side in the axial direction is fixed to the shaft, and the outer circumferential side is at a position radially outside the cam. A flexible annular external gear having external teeth;
The external gear is disposed between the external gear and the cam, and supports the external gear and the cam so as to be relatively rotatable, and the external gear according to rotation of the cam accompanying rotation of the rotating body. A flexible bearing that deforms radially outward;
An annular internal gear that is disposed so as to surround the external gear from the outside in the radial direction and has internal teeth that mesh with the external teeth on the inner peripheral side;
An output portion having a flat plate portion connected to the internal gear and extending in a direction crossing the axial direction; and a cylindrical portion extending from the flat plate portion in the axial direction;
A first bearing that is located between the shaft and the tubular portion and that rotatably supports the output portion with respect to the shaft;
A second bearing that is positioned between the cylindrical part and the rotating body and supports the output part and the rotating body in a relatively rotatable manner;
With
The motor-driven wave gear reducer, wherein the flexible bearing, the first bearing, and the second bearing are arranged side by side in a direction orthogonal to the axial direction at a predetermined position in the axial direction. In the wave gear reducer with an electric motor according to claim 1,
The external gear is fixed to the shaft on one side of the motor in the axial direction,
The said flexible bearing, the said 1st bearing, and the said 2nd bearing are the wave gear reducers with an electric motor arrange | positioned in the said axial direction at the other side rather than the said electric motor. In the wave gear reducer with an electric motor according to claim 1 or 2,
The rotor is cylindrical,
A wave gear reducer with an electric motor, wherein an outer diameter of the cam is smaller than an outer diameter of the rotor. In the wave gear reducer with an electric motor according to any one of claims 1 to 3,
The external gear has a bottom portion and a cylindrical side wall portion extending from the bottom portion in the axial direction.
The shaft passes through the bottom and is connected to the bottom;
The electric motor is a wave gear reducer with an electric motor disposed inside the external gear. In the wave gear reducer with an electric motor according to any one of claims 1 to 4,
The wave gear reducer with an electric motor, wherein the shaft is a hollow shaft. A first arm;
A second arm rotatably connected to the first arm;
A drive unit that relatively rotates the first arm and the second arm;
The articulated robot, wherein the drive unit is a wave gear reducer with an electric motor according to any one of claims 1 to 5. The articulated robot according to claim 6, wherein
A connecting portion between the first arm and the second arm penetrates a main shaft that connects the first arm and the second arm so as to be relatively rotatable,
The main shaft is fixed to the second arm;
The wave gear reducer with an electric motor is an articulated robot that is fixed to the main shaft while the main shaft passes through the shaft of a hollow shaft, and the output unit is connected to the first arm.

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