JP2010210073A - Drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep the cost of parts from increasing when the outside diameter of an input shaft in a drive unit is changed. <P>SOLUTION: The drive unit 2 includes: an input shaft 6; a motor 12 for rotating the input shaft 6; a reduction gear 18 connected to one mating member 50 and the other mating member 52 and reducing the speed of rotation of the input shaft 6 to cause relative rotation between the one mating member 50 and the other mating member 52 at numbers of rotation after the reduction of the speed; a driven rotor 14 which rotates radially outside of the input shaft 6 as the input shaft 6 rotates; and an encoder 16 provided in a predetermined position on the outside of the motor 12 along the radial direction of the input shaft 6 for detecting the amount of rotation of the driven rotor 14. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a drive device.

  Conventionally, a driving device for rotating a driven body around a predetermined axis is known, and an example of such a driving device is shown in Patent Document 1 below.

  FIG. 4 is a cross-sectional view showing the structure of the driving device disclosed in Patent Document 1. In this drive device, the rotation of the input shaft 104 rotated by the drive of the motor 102 is decelerated by the differential oscillating speed reducer 106 and then transmitted to the driven body to rotationally drive the driven body.

  Specifically, a hollow input shaft 104 is provided coaxially with the drive device in the drive device, and an annular motor 102 is provided on the outer periphery of the input shaft 104. A rotating sleeve 108 is connected to one end of the input shaft 104 so as to be coaxial with the input shaft 104, and the rotating sleeve 108 and the input shaft 104 can rotate integrally. Around the rotary sleeve 108, a differential oscillating speed reducer 106 connected to the driven body is provided. The rotational force of the rotating sleeve 108 that rotates together with the input shaft 104 is input to the differential oscillation type speed reducer 106 and decelerated by the speed reducer 106 so that the rotational force after the deceleration is applied to the driven body. It has become.

  An encoder 110 for detecting the amount of rotation of the input shaft 104 is provided in the drive device. The encoder 110 is formed in an annular shape, and is externally fitted to the input shaft 104 at a position opposite to the rotating sleeve 108 with respect to the stator 102a and the rotor 102b of the motor 102.

Japanese Utility Model Publication No. 3-65039

  However, in the above-described conventional driving device, since the annular encoder 110 is externally fitted to the input shaft 104, the inner diameter corresponding to the outer diameter of the input shaft 104 is changed when the outer diameter of the input shaft 104 is changed. Therefore, it is necessary to prepare a plurality of encoders 110 having different inner diameters. As a result, there arises a problem that the component cost increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to suppress an increase in component costs that occurs when the outer diameter of the input shaft is changed in the drive device.

  In order to achieve the above object, a driving apparatus according to the present invention is a driving apparatus for relatively rotating a one-side mating member and an other-side mating member, and rotates an input shaft and the input shaft. And the one-side mating member and the other-side mating member are respectively connected, decelerate the rotation of the input shaft, and the one-side mating member and the other-side mating member at the number of rotations after the deceleration. , A first rotating body that rotates radially outside the input shaft as the input shaft rotates, and a predetermined location outside the motor in the radial direction of the input shaft. And an encoder for detecting a rotation amount of the first rotating body.

  In this drive device, the first rotating body rotates on the outer side in the radial direction of the input shaft as the input shaft rotates, and the rotation amount of the first rotating body is set at a predetermined position outside the motor in the radial direction of the input shaft. Unlike the conventional configuration in which the amount of rotation of the input shaft is detected by an annular encoder that is externally fitted to the input shaft, the encoder is installed even when the outer diameter of the input shaft is changed. There is no need to change, and the same encoder can be used as it is. Therefore, in this drive device, it is possible to suppress an increase in the component cost of the drive device that occurs when the outer diameter of the input shaft is changed.

  The drive device includes a second rotating body that is fitted around the input shaft so as to be coaxial with the input shaft and rotates integrally with the input shaft, and the first rotating body is radially outside of the second rotating body. The second rotating body is provided separately from the second rotating body, contacts the outer surface of the second rotating body, receives the rotational force of the second rotating body from the contact portion, and is radially outward of the second rotating body. It is preferred to rotate around the axis in which it is located.

  In this configuration, the first rotating body provided separately from the second rotating body that rotates integrally with the input shaft receives the rotational force of the second rotating body and is positioned on the radially outer side of the second rotating body. Therefore, even if the input shaft generates vibration during rotation and the vibration is transmitted to the second rotating body, the rotation between the second rotating body and the first rotating body. As a result, it is possible to suppress the adverse effect caused by the vibration of the input shaft when the encoder detects the rotation amount of the first rotating body. Therefore, with this configuration, even when vibration occurs on the input shaft, it is possible to suppress a decrease in the detection accuracy of the rotation amount of the input shaft based on the detection result of the encoder.

  In this case, it is preferable that the first rotating body is configured to rotate at a rotational speed increased by a predetermined ratio with respect to the rotational speed of the second rotating body.

  If comprised in this way, since the rotation amount of a 1st rotary body becomes the rotation amount multiplied by the predetermined ratio with respect to the rotation amount of a 2nd rotary body, in an encoder, the 1st multiplied 1st is carried out. The amount of rotation of the rotating body can be detected. For this reason, even if the resolution of the encoder is low, the amount of rotation can be detected with good accuracy. Therefore, in this configuration, a low-resolution encoder can be used to detect the amount of rotation, and the component cost can be reduced compared to the case where an expensive high-resolution encoder is used.

  In the above drive device, the motor includes an annular stator, a rotor that is provided on the radially inner side of the stator and that is externally fitted to the input shaft and is driven to rotate about the shaft. It is preferable to have a portion arranged to overlap the stator and the rotor in the axial direction of the input shaft at a predetermined location on the radially outer side of the stator.

  In this configuration, since the encoder has a portion that overlaps the stator and rotor and the input shaft in the axial direction, the encoder and the stator and rotor of the motor are arranged side by side in the axial direction of the input shaft. Thus, it is possible to reduce the size of the drive device in the axial direction of the input shaft.

  In the above drive device, the speed reducer is fixed to one of the one-side mating member and the other-side mating member, an outer cylinder having a plurality of internal teeth on the inner surface, and an eccentricity provided on the input shaft. An external gear that is attached to the eccentric portion and is capable of swinging and rotating within the outer cylinder while meshing with the internal teeth in conjunction with rotation of the input shaft, the one-side mating member, and the other-side mating member It is preferable to have a carrier connected to the other of the members and rotating in conjunction with the swinging rotation of the external gear.

  As a configuration of a speed reducer that relatively rotates the one-side mating member and the other-side mating member at a rotational speed reduced from the rotational speed of the input shaft, the rotation of the input shaft is separated from the input shaft via a transmission gear. A configuration is also conceivable in which the carrier and the mating member connected to the carrier are rotated by swinging and rotating the external gear attached to the eccentric portion of the crankshaft. However, in such a reduction gear, it is necessary to provide a crankshaft and a transmission gear separately from the input shaft, and the number of parts increases. On the other hand, in this configuration, in the speed reducer, the external gear attached to the eccentric part provided on the input shaft swings and rotates in conjunction with the rotation of the input shaft, and is connected to the carrier. Since the mated member rotates, the crankshaft and the transmission gear need not be provided separately from the input shaft as in the case of the speed reducer described above. Therefore, in this configuration, an increase in the number of parts can be suppressed.

  In the above drive device, it is preferable that the input shaft is provided with a shaft hole penetrating in the axial direction.

  If comprised in this way, various wiring can be provided so that the shaft hole of an input shaft may be passed. In this configuration, if the outer diameter of the input shaft is increased and the inner diameter of the shaft hole is increased, a large space for passing various wires through the input shaft can be secured. In this case, in the configuration in which the annular encoder is externally fitted to the input shaft, there is a problem of an increase in parts cost as described above. However, in the present invention, the encoder is placed at a predetermined position outside the motor in the radial direction of the input shaft. Due to the fact that it is provided, it is not necessary to change the encoder even if the outer diameter of the input shaft is increased, and an increase in the cost of components can be suppressed. Therefore, in this configuration, it is possible to suppress an increase in component costs while securing a large space for passing various wires in the input shaft.

  As described above, according to the present invention, it is possible to suppress an increase in component costs that occurs when the outer diameter of the input shaft is changed in the drive device.

It is sectional drawing of the drive device by one Embodiment of this invention. It is sectional drawing of the drive device along the II-II line | wire in FIG. It is sectional drawing of the drive device by the modification of one Embodiment of this invention. It is sectional drawing of the drive device by an example of the past.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, with reference to FIG.1 and FIG.2, the structure of the drive device 2 by one Embodiment of this invention is demonstrated.

  The drive device 2 according to the present embodiment is used for a joint part of a robot or various machines, or a drive part of a machine tool or the like, and is provided between a pair of partner members 50 and 52 so that the partner members 50 and 52 are relative to each other. Is rotationally driven. Hereinafter, one counterpart member 50 is referred to as one side counterpart member 50, and the other counterpart member 52 is referred to as the other side counterpart member 52. The drive device 2 of the present embodiment includes a cover 4, an input shaft 6, a first bearing 8, a second bearing 10, a motor 12, an integral rotating body 13, a driven rotating body 14, an encoder 16, A reduction gear 18.

  The cover 4 is provided with a through hole 4a through which the input shaft 6 is inserted. One end surface (right end surface) of the cover 4 is in contact with one end surface (left end surface) of a carrier 28 (to be described later) of the speed reducer 18 in the axial direction (left and right direction in FIG. 1) of the through hole 4a. The cover 4 is fastened to the carrier 28 by bolts 5. The cover 4 is fixed to the one-side mating member 50 in a state where the other end surface (left end surface) in the axial direction of the through hole 4 a is in contact with the one-side mating member 50.

  A portion of the cover 4 having a predetermined length from the right end surface along the axial direction of the through hole 4a is a first portion 4b having a relatively large inner diameter. The first portion 4b is formed with a notch 4d in a part in the circumferential direction. Further, a portion of the cover 4 that is continuously provided on the side opposite to the right end surface with respect to the first portion 4b is a second portion 4c having an inner diameter smaller than that of the first portion 4b. A first bearing 8 is fitted in the through hole 4a of the second portion 4c, and the input shaft 6 is supported by the second portion 4c via the first bearing 8.

  A seal member 19 is provided at a position on the one-side mating member 50 side with respect to the first bearing 8 in the gap between the inner surface of the through hole 4a of the second portion 4c and the outer peripheral surface of the input shaft 6. This prevents foreign matter from entering the inside of the driving device 2 from this portion.

  The input shaft 6 protrudes from the right end surface of the cover 4 and extends over the entire length of the drive device 2 in the axial direction (left-right direction in FIG. 1). The input shaft 6 is provided with a shaft hole 6a penetrating in the axial direction. The shaft hole 6 a is provided such that its axis coincides with the axis of the input shaft 6. That is, the input shaft 6 is formed in a substantially cylindrical shape. Various wires and the like can be provided so as to extend from the one-side mating member 50 to the other-side mating member 52 through the shaft hole 6 a of the input shaft 6.

  The motor 12 is for rotating the input shaft 6, and is disposed in the space inside the first portion 4 b of the cover 4. The motor 12 has a stator 12a and a rotor 12b.

  The stator 12a is formed in an annular shape, is disposed on the outer periphery of the input shaft 6 in the inner space of the first portion 4b, and is fixed to the left end surface of a carrier 28 described later. The stator 12 a has an inner diameter such that a gap is formed between the inner surface of the stator 12 a and the outer surface of the input shaft 6.

  The rotor 12b is formed in an annular shape, is provided on the inner side in the radial direction of the stator 12a, and is externally fitted to the input shaft 6 and fixed. In the motor 12, the rotor 12b is driven to rotate about its axis, thereby rotating the input shaft 6 fitted to the rotor 12b.

  The integral rotating body 13 is composed of an external gear, and is fitted and fixed to a portion of the input shaft 6 that protrudes from the right end surface of the cover 4 toward the other-side mating member 52 so as to be coaxial with the input shaft 6. Yes. Thereby, the integral rotating body 13 rotates integrally with the input shaft 6. The integral rotating body 13 is included in the concept of the second rotating body of the present invention. The integral rotating body 13 is disposed at a position separated from the stator 12a and the rotor 12b of the motor 12 toward the other-side mating member 52 in the axial direction of the input shaft 6.

  The driven rotator 14 is provided separately from the integral rotator 13 on the radially outer side of the integral rotator 13, and is positioned on the radially outer side of the integral rotator 13 by receiving the rotational force of the integral rotator 13. It rotates around the axis. That is, the driven rotating body 14 rotates on the radially outer side of the input shaft 6 as the input shaft 6 rotates. The driven rotator 14 is included in the concept of the first rotator of the present invention. The driven rotator 14 includes a rotated portion 14a, a transmission shaft 14b, and a rotating plate 14c.

  The rotated portion 14a is an external gear that meshes with the external gear of the integral rotating body 13, and is attached so that the transmission shaft 14b is coaxial with the rotated portion 14a. Both the external gear constituting the rotated portion 14a and the external gear constituting the integral rotating body 13 are arranged inside the speed reducer 18, and lubrication using the lubricating oil filled in the speed reducer 18 is performed. It is possible. The transmission shaft 14b extends from the rotated portion 14a to the cover 4 side in parallel with the input shaft 6 through an insertion hole 28e of the carrier 28 described later. The transmission shaft 14b is pivotally supported by a bearing 24 provided in the insertion hole 28e of the carrier 28 and is rotatable. The end of the transmission shaft 14b opposite to the side attached to the rotated portion 14a protrudes into the notch 4d of the cover 4, and the rotating plate 14c is attached to this end. The rotating plate 14c is attached to the transmission shaft 14b so that the axis of the transmission shaft 14b coincides with the axis. The transmission shaft 14b is arranged such that its axial center is located further radially outward than the radially outer position from the outer peripheral portion of the stator 12a of the motor 12 by the radius of the rotating plate 14c. With such a configuration, the rotation of the input shaft 6 is transmitted from the integral rotator 13 to the rotated portion 14a of the driven rotator 14, whereby the rotated portion 14a, the transmission shaft 14b, and the rotating plate 14c are integrally formed. It is designed to rotate.

  The driven rotator 14 is configured to rotate at a rotational speed increased by a predetermined ratio with respect to the rotational speed of the integral rotator 13. That is, the number of teeth of the rotated portion 14a of the driven rotating body 14 is smaller than the number of teeth of the external gear of the integrated rotating body 13, and the rotation is transmitted from the integrated rotating body 13 to the rotated portion 14a. In addition, the number of rotations is increased according to the ratio between the number of teeth of the integral rotating body 13 and the number of teeth of the rotated portion 14a.

  The encoder 16 detects the amount of rotation of the driven rotor 14. Specifically, the encoder 16 detects the amount of rotation of the rotating plate 14 c of the driven rotor 14. The encoder 16 is provided at a predetermined location outside the motor 12 in the radial direction of the input shaft 6, that is, outside the motor 12 (stator 12 a) in the radial direction, and is disposed in the notch 4 d of the cover 4. . The encoder 16 is disposed so as to overlap the stator 12 a and the rotor 12 b of the motor 12 in the axial direction of the input shaft 6. The encoder 16 is fixed to a carrier 28 described later. The rotation amount data of the rotating plate 14c detected by the encoder 16 is input to a calculation unit of a control unit (not shown). In this calculation unit, the number of teeth of the integral rotating body 13 and the teeth of the rotated portion 14a. The rotation amount of the input shaft 6 is calculated from the relationship between the rotation amount of the rotary plate 14c and the rotation amount of the input shaft 6 set in advance from the ratio to the number and the input rotation amount data of the rotary plate 14c. It has become so. Further, the calculation unit calculates a relative position in the rotation direction of the counterpart members 50 and 52 based on the calculated rotation amount data of the input shaft 6 and a reduction ratio of the speed reducer 18 described later, and based on the calculation result. Thus, the control unit performs drive control of the motor 12.

  The reduction gear 18 is connected to the one-side mating member 50 and the other-side mating member 52, respectively, and decelerates the rotation of the input shaft 6 at a predetermined reduction ratio, and the one-side mating member at the speed after the deceleration. 50 and the other-side counterpart member 52 are rotated relative to each other. The speed reducer 18 includes an outer cylinder 26, a carrier 28, a shaft 29, a main bearing 30, an external gear 32, an eccentric portion 34, and a rolling bearing 35.

  The outer cylinder 26 has a cylindrical shape that is short in the axial direction (left-right direction in FIG. 1), and a portion of the input shaft 6 that protrudes from the right end surface of the cover 4 is inserted into the outer cylinder 26. The outer cylinder 26 is arranged so that the position of the input shaft 6 and the axial center coincide. The outer cylinder 26 includes a cylindrical main body portion 36 and a flange portion 38 provided so as to protrude radially outward from the main body portion 36. The flange portion 38 is provided with bolt insertion holes 38a at equal intervals in the circumferential direction. The bolt insertion hole 38 a is used for fastening the outer cylinder 26 to the other-side mating member 52.

  The main body portion 36 includes a first member 39 and a second member 40 that are arranged side by side in the axial direction, and the first end surface 39 a of the first member 39 and the first end surface 40 a of the second member 40. The first member 39 and the second member 40 are fastened to each other by a bolt 41 in a state in which they are in contact with each other. The first member 39 and the second member 40 are both formed in a cylindrical shape, and both the members 39 and 40 have inner peripheral surfaces having the same inner diameter.

  On the second end surface 39b side, which is the end surface opposite to the first end surface 39a in the axial direction of the first member 39, the other-side mating member 52 is attached with a thin plate-like oil cover 42 interposed therebetween. The oil cover 42 is fastened to the first member 39. A through hole 42a is provided in the center of the oil cover 42, and the end of the input shaft 6 is inserted into the through hole 42a. A seal member 43 is fitted between the inner peripheral surface of the through hole 42 a of the oil cover 42 and the outer peripheral surface of the end portion of the input shaft 6. The internal space of the outer cylinder 26 is filled with lubricating oil, and the sealing member 43 and the oil cover 42 prevent the lubricating oil from leaking from the second end face 39 b side of the first member 39.

  The first member 39 is integrally formed with the flange portion 38 on the outer peripheral portion thereof, while the inner peripheral surface of the first member 39 is equally spaced in the circumferential direction as shown in FIG. A plurality of circular grooves are formed. In each circular groove, a cylindrical inner tooth pin 44 that functions as an inner tooth of the outer cylinder 26 is fitted. The external gear 32 is disposed close to the cover 4 within the outer cylinder 26 and meshes with the internal pin 44.

  The second member 40 has a recess 40c formed on the inner peripheral surface thereof at a portion opposite to the first member 39, and the inner diameter is increased at this portion. A seal member 45 is disposed in the recess 40c. Thereby, the lubricating oil filled in the internal space of the outer cylinder 26 is prevented from leaking from the second member 40.

  The carrier 28 is disposed in the outer cylinder 26 at a position opposite to the side where the external gear 32 is disposed. The carrier 28 is supported by the outer cylinder 26 by the main bearing 30 and is rotatable relative to the outer cylinder 26 on the same axis. The carrier 28 is fastened by the cover 4 and the bolt 5 as described above, and the cover 4 is fixed to the one-side mating member 50. That is, the carrier 28 is connected to the one-side mating member 50 through the cover 4. The relative rotation between the carrier 28 and the outer cylinder 26 enables the relative rotation between the one-side mating member 50 and the other-side mating member 52 at the joint.

  The main bearing 30 is on the same side as the carrier 28 with respect to the external gear 32 in the axial direction of the input shaft 6, and is disposed where the first member 39 and the second member 40 of the outer cylinder 26 are in contact with each other. Has been. Specifically, a conical surface (first conical surface) 39d that is inclined with respect to the inner peripheral surface is formed on the first end surface 39a of the first member 39, and the first end surface 40a of the second member 40 also has an inner surface. A conical surface (second conical surface) 40d inclined with respect to the peripheral surface is formed. The first conical surface 39d and the second conical surface 40d constitute a concave groove having a triangular cross-section extending over the entire inner circumferential surface of the outer cylinder 26 in the circumferential direction.

On the other hand, a concave groove 28a is formed on the outer peripheral surface of the carrier 28 so as to correspond to both the conical surfaces 39d and 40d. The concave groove 28 a has a first conical surface 28 b parallel to the first conical surface 39 d of the first member 39 and a second conical surface 28 c parallel to the second conical surface 40 d of the second member 40.
The main bearing 30 is formed of a cross roller bearing, and the roller 30a is disposed so as to contact the conical surfaces 39d, 40d, 28b, 28c, and the conical surfaces 39d, 40d, 28b, 28c. It is held so that it can roll.

  The carrier 28 is formed with a central through hole 28d so that the position of the outer cylinder 26 and the shaft center coincide with each other, and the external gear 32 similarly has a center so that the position of the outer cylinder 26 and the shaft center coincide with each other. A through hole 32a is formed. A portion of the input shaft 6 protruding from the right end surface of the cover 4 is inserted through the central through holes 28d and 32a. The integral rotating body 13 and the rotated portion 14 a are disposed in a space between the carrier 28 and the external gear 32 in the outer cylinder 26.

  The second bearing 10 is fitted in the central through hole 28 d of the carrier 28. The input shaft 6 is rotatably supported by the second bearing 10 and the first bearing 8. As a result, the input shaft 6 can rotate relative to the carrier 28 and the cover 4. A seal member 46 is provided at a position opposite to the external gear 32 with respect to the second bearing 10 in the gap between the outer peripheral surface of the input shaft 6 and the inner surface of the central through hole 28d of the carrier 28. The lubricating oil filled in the outer cylinder 26 is prevented from leaking from this portion. Therefore, the motor 12 (the stator 12a and the rotor 12b) is prevented from being affected by the lubricant. In this configuration, the first bearing 8 is preferably a sealed bearing type in which a lubricant is sealed.

  The right end surface of the cover 4 is brought into contact with the vicinity of the outer edge of the end surface (left end surface) opposite to the external gear 32 in the axial direction of the carrier 28, and the cover 4 and the carrier 28 are fastened in this state. Accordingly, the carrier 28 is connected to the one-side mating member 50 through the cover 4. And the stator 12a of the motor 12 is being fixed to the location inside radial direction rather than the location where the cover 4 is contact | abutting among the left end surfaces of the carrier 28. FIG.

  An insertion hole 28 e is formed in the carrier 28 at a position outside the central through hole 28 d in the radial direction and corresponding to the cutout portion 4 d of the cover 4. The transmission shaft 14b of the driven rotator 14 is inserted into the insertion hole 28e as described above, and the transmission shaft 14b is rotatably supported by the bearing 24 attached in the insertion hole 28e. A seal member 47 is provided at a position on the cover 4 side with respect to the bearing 24 in the gap between the inner surface of the insertion hole 28e and the outer peripheral surface of the transmission shaft 14b, and lubrication filled in the outer cylinder 26 is performed. Oil is prevented from leaking out of this area.

  The carrier 28 is provided with a plurality of shaft holes 28f around the central through hole 28d. The shaft holes 28f are arranged at equal intervals in the circumferential direction. A shaft 29 is press-fitted into each shaft hole 28 f, and these shafts 29 extend from the carrier 28 along the axial direction of the input shaft 6 toward the external gear 32.

The external gear 32 is formed with through holes 32 d at positions corresponding to the shaft holes 28 f of the carrier 28. A shaft 29 corresponding to each through hole 32d is inserted with play. The number of teeth of the external gear 32 is slightly smaller than the number of internal teeth pins 44 provided on the inner surface of the outer cylinder 26. The eccentric portion 34 is the main body of the outer cylinder 26 of the input shaft 6. It is provided at a portion of the portion 36 disposed in the first member 39 and is formed integrally with the input shaft 6. The eccentric part 34 is provided such that its axis is eccentric from the axis of the main body part 6 b of the input shaft 6. An external gear 32 is attached to the eccentric portion 34 via a rolling bearing 35. That is, the eccentric portion 34 is inserted into the central through hole 32 a of the external gear 32, and the rolling bearing 35 is interposed between the outer peripheral surface of the eccentric portion 34 and the inner surface of the central through hole 32 a of the external gear 32. It is disguised.

  Next, the operation of the drive device 2 according to the present embodiment will be described.

  In the drive device 2 according to the present embodiment, the rotor 12b of the motor 12 is rotationally driven, whereby the input shaft 6 rotates. At this time, the eccentric portion 34 rotates together with the input shaft 6, and accordingly, the external gear 32 swings and rotates while meshing with the internal tooth pin 44. The rotation of the external gear 32 is transmitted to the carrier 28 via the shaft 29, whereby the carrier 28 rotates relative to the outer cylinder 26. That is, the carrier 28 rotates relative to the outer cylinder 26 in conjunction with the swinging rotation of the external gear 32. The rotational speed of the carrier 28 is a rotational speed reduced from the rotational speed of the input shaft 6 according to the ratio of the number of teeth of the external gear 32 and the number of internal teeth pins. When the carrier 28 and the outer cylinder 26 are relatively rotated, the one-side mating member 50 connected to the carrier 28 via the cover 4 and the other-side mating member 52 fastened to the outer cylinder 26 are relatively Rotate.

  On the other hand, the integral rotating body 13 rotates with the rotation of the input shaft 6, and the rotation of the integral rotating body 13 is transmitted to the rotating plate 14 c via the rotated portion 14 a and the transmission shaft 14 b of the driven rotating body 14. . The encoder 16 detects the amount of rotation of the rotating plate 14c, and the detected data is input to the calculation unit of the control unit. The calculation unit calculates the rotation amount of the input shaft 6 based on the detection data, that is, the rotation amount data of the rotation plate 14c and the relationship between the rotation amount of the rotation plate 14c and the rotation amount of the input shaft 6 set in advance. While calculating, the relative position in the rotation direction of the other members 50 and 52 is calculated based on the calculated rotation amount data of the input shaft 6 and the reduction ratio of the speed reducer 18. And based on this calculation result, a control part performs drive control of the motor 12, and controls the relative position in the rotation direction of the other members 50 and 52 by it.

  As described above, in the driving device 2 according to the present embodiment, the driven rotating body 14 rotates on the radially outer side of the input shaft 6 as the input shaft 6 rotates, and the rotating plate 14c of the driven rotating body 14 is rotated. Since the rotation amount is detected by an encoder 16 provided at a predetermined location outside the motor 12 in the radial direction of the input shaft 6, the rotation amount of the input shaft is detected by an annular encoder fitted on the input shaft. Unlike the configuration for detecting, the encoder 16 does not need to be changed even when the outer diameter of the input shaft 6 is changed, and the same encoder 16 can be used as it is. Therefore, in the present embodiment, it is possible to suppress an increase in the component cost of the drive device 2 that occurs when the outer diameter of the input shaft 6 is changed.

  In the present embodiment, the driven rotating body 14 is provided separately from the integrated rotating body 13 at a predetermined location on the radially outer side of the integrated rotating body 13 that rotates integrally with the input shaft 6. Since the rotated portion 14a meshes with the external gear of the integral rotating body 13 and rotates around the shaft positioned on the radially outer side of the integral rotating body 13, the input shaft 6 generates vibration during rotation and the vibration is integrated. Even if it is transmitted to the rotating body 13, the transmission of vibrations is mitigated between the external gear of the integral rotating body 13 and the external gear of the rotated portion 14 a of the driven rotating body 14. In this embodiment, since the encoder 16 detects the amount of rotation of the rotating plate 14c of the driven rotor 14, the detection of this amount of rotation is prevented from being adversely affected by the vibration of the input shaft 6. it can. Therefore, in this embodiment, even when vibration occurs in the input shaft 6, it is possible to suppress a decrease in the detection accuracy of the rotation amount of the input shaft 6 based on the detection result of the encoder 16.

  Further, in this embodiment, since the driven rotator 14 rotates at a rotational speed increased by a predetermined ratio with respect to the rotational speed of the integral rotator 13, the rotation amount of the driven rotator 14 is the rotation of the integral rotator 13. The rotation amount is multiplied by a predetermined ratio with respect to the amount. Therefore, the encoder 16 can detect the amount of rotation of the multiplied rotating plate 14c of the driven rotor 14 and can detect the amount of rotation with good accuracy even if the resolution of the encoder 16 is low. it can. Therefore, in this embodiment, the low-resolution encoder 16 can be used for detecting the rotation amount, and the component cost can be reduced as compared with the case of using an expensive high-resolution encoder.

  In the present embodiment, the encoder 16 and the stator 12a are disposed so as to overlap with each other in the axial direction of the stator 12a, the rotor 12b, and the input shaft 6 at a predetermined position on the radially outer side of the stator 12a of the motor 12. As compared with the structure in which the rotor 12b and the rotor 12b are arranged side by side in the axial direction of the input shaft 6, the size of the drive device 2 in the axial direction of the input shaft 6 can be reduced.

  Further, in the present embodiment, in the speed reducer 18, the carrier 28 and its carrier according to the external gear 32 attached to the eccentric portion 34 of the input shaft 6 swinging and rotating in conjunction with the rotation of the input shaft 6. Since the one-side mating member 50 connected to 28 rotates relative to the other-side mating member 52, it is not necessary to provide a crankshaft or a transmission gear separately from the input shaft 6. Therefore, in this embodiment, an increase in the number of parts can be suppressed.

  Furthermore, in this embodiment, since only one external gear 32 is used in the speed reducer 18, an increase in the size of the speed reducer 18 in the axial direction of the input shaft 6 is suppressed, and the shaft of the input shaft 6 is reduced. The increase in the dimension of the driving device 2 in the direction is suppressed.

  In the present embodiment, since the shaft hole 6a penetrating in the axial direction is provided in the input shaft 6, various wirings can be provided so as to pass through the shaft hole 6a. In this embodiment, if the outer diameter of the input shaft 6 is increased and the inner diameter of the shaft hole 6a is increased, a large space for passing various wires through the input shaft 6 can be secured. In this case, in the configuration in which the annular encoder is externally fitted to the input shaft, there is a problem of an increase in the component cost as described above. However, in this embodiment, the encoder 16 is connected to the motor 12 in the radial direction of the input shaft 6. Due to the fact that the outer diameter of the input shaft 6 is increased, there is no need to change the encoder 16 due to the fact that it is provided at a predetermined position on the outer side, and an increase in component costs can be suppressed. Therefore, in this embodiment, it is possible to suppress an increase in component costs while securing a large space for passing various wirings in the input shaft 6.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, the integral rotating body 13 and the driven rotating body 14 may be disposed outside the speed reducer 18 as in a modification of the above-described embodiment illustrated in FIG. Specifically, in this modification, the integral rotating body 13 is disposed in the cover 4 at a position opposite to the carrier 28 with respect to the motor 12, and the integral rotating body 13 is connected to the input shaft 6 at that position. It is fitted. The rotated portion 14 a of the driven rotor 14 is disposed in the cutout portion 4 d of the cover 4. A mounting hole 4f extends parallel to the through hole 4a and penetrates the second part 4c at a position corresponding to the notch 4d on the radially outer side of the through hole 4a in the second part 4c of the cover 4. Is formed. One end of the transmission shaft 14b is attached to the attachment hole 4f via a bearing 24. The mounting hole 4f is formed at a position such that the shaft center of the transmission shaft 14b is disposed further radially outward than the radially outer position from the outer peripheral portion of the stator 12a of the motor 12 by the radius of the rotating plate 14c. ing. A cap 48 is fitted into the end of the mounting hole 4f on the one-side mating member 50 side, and foreign matter is prevented from entering from this portion.

  The transmission shaft 14b protrudes from the mounting hole 4f into the notch 4d and extends toward the reduction gear 18 in parallel with the input shaft 6. The rotated portion 14a is fitted on a portion of the transmission shaft 14b that protrudes into the cutout portion 4d. The rotating plate 14c is attached to the distal end portion of the transmission shaft 14b located closer to the speed reducer 18 than the position where the rotated portion 14a is provided in the cutout portion 4d. The encoder 16 is fixed to the end face on the reduction gear 18 side of the second portion 4c of the cover 4 in the notch 4d.

  In the case of this modification, unlike the above embodiment, the external gear of the integral rotating body 13 and the rotated portion 14a of the driven rotating body 14 cannot be lubricated using the lubricating oil filled in the outer cylinder 26. Therefore, it is preferable to use plastics that do not require lubrication as both gears.

  Moreover, the 1st rotary body of this invention is comprised by the rotating plate externally fitted to the input shaft 6, and rotates integrally with the input shaft 6, and an encoder detects the rotation amount of this rotating plate. It may be. That is, the rotating plate rotates coaxially with the input shaft 6 on the radially outer side of the input shaft 6 as the input shaft 6 rotates.

  Moreover, while using the magnetic disc fitted to the input shaft 6 as the integral rotating body 13, and using the magnetic disc as the rotated portion 14a of the driven rotating body 14, the outer peripheral surface of the magnetic disc of the integral rotating body 13 is used. You may arrange | position those magnetic discs so that the outer peripheral surface of the magnetic disc of the to-be-rotated part 14a may adsorb | suck with magnetic force. In this configuration, when the magnetic disk of the integral rotating body 13 rotates with the rotation of the input shaft 6, the magnetic disk of the driven rotating body 14 rotates by being attracted by the magnetic force. The radius of the magnetic disk of the rotated part 14a is smaller than the radius of the magnetic disk of the integral rotating body 13, and the rotation is transmitted from the integrated rotating body 13 to the rotated part 14a. The rotational speed is increased according to the ratio of the radius of the rotating body 13 and the radius of the rotated portion 14a. When vibration occurs in the input shaft 6, the magnetic disk of the integral rotating body 13 vibrates together with the input shaft 6. However, the magnetic disk of the integral rotating body 13 and the magnetic disk of the rotated portion 14a A relative positional shift occurs between the magnetic disks of the integrated rotating body 13 and the magnetic disk of the rotated portion 14a.

  Further, only a part of the encoder 16 may overlap with the stator 12 a and the rotor 12 b of the motor 12 in the axial direction of the input shaft 6.

  Moreover, the attitude | position which arrange | positions the drive device 2 is not limited to an above-described attitude | position. That is, the driving device 2 may be provided so that the axial direction is arranged in various directions other than the left-right direction.

2 Driving device 6 Input shaft 6a Shaft hole 12 Motor 12a Stator 12b Rotor 13 Integrated rotating body (second rotating body)
14 Followed rotating body (first rotating body)
16 Encoder 18 Reduction gear 26 Outer cylinder 28 Carrier 32 External gear 34 Eccentric part 44 Internal tooth pin (internal tooth)
50 One side mating member 52 Other side mating member

Claims (6)

A driving device for relatively rotating and driving the one-side mating member and the other-side mating member,
An input shaft;
A motor for rotating the input shaft;
Connected to the one-side mating member and the other-side mating member, respectively, the rotation of the input shaft is decelerated, and the one-side mating member and the other-side mating member are relatively rotated at the number of rotations after the deceleration. A reducer,
A first rotating body that rotates radially outward of the input shaft as the input shaft rotates;
A drive device comprising: an encoder that is provided at a predetermined location outside the motor in a radial direction of the input shaft and detects a rotation amount of the first rotating body. A second rotating body that is externally fitted to be coaxial with the input shaft and rotates integrally with the input shaft;
The first rotating body is provided separately from the second rotating body on the radially outer side of the second rotating body, contacts the outer surface of the second rotating body, and contacts the second rotating body from the contact portion. The driving device according to claim 1, wherein the driving device is rotated around an axis positioned on a radially outer side of the second rotating body in response to the rotational force of the second rotating body.   The drive device according to claim 2, wherein the first rotating body is configured to rotate at a rotational speed increased by a predetermined ratio with respect to the rotational speed of the second rotating body. The motor includes an annular stator and a rotor that is provided on the radially inner side of the stator and is externally fitted to the input shaft and is driven to rotate about the shaft.
The drive according to any one of claims 1 to 3, wherein the encoder has a portion that is arranged in a predetermined position outside the stator in the radial direction so as to overlap the stator and the rotor in the axial direction of the input shaft. apparatus.   The speed reducer is fixed to one of the one-side mating member and the other-side mating member, an outer cylinder having a plurality of inner teeth on the inner surface, an eccentric portion provided on the input shaft, and the eccentricity An external gear that is attached to a portion and is capable of swinging and rotating within the outer cylinder while meshing with the internal teeth in conjunction with rotation of the input shaft, and the other of the one-side mating member and the other-side mating member The drive device according to any one of claims 1 to 4, further comprising a carrier that is connected and rotates in conjunction with the rocking rotation of the external gear.   The drive device according to claim 1, wherein the input shaft is provided with a shaft hole penetrating in the axial direction.

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