JP2020148324A - Drive device, robot and image forming device - Google Patents

Abstract

To provide a drive device capable of improving abrasion resistance and strength of a gear close to an output shaft on a drive transmission system path.SOLUTION: In a drive device that rotates the same output shaft 2 by two motors 9A, 9B, two planetary type planetary gear mechanisms are configured so that an external gear 5 and a carrier 2 are shared, and planetary gears 3A, 3B and sun gears 4A and 4B are dedicated, and drive is respectively transmitted from the two motors 9A, 9B to the sun gears 4A, 4B. The drive device has control means 11 that performs control capable of reducing backlash by the two motors 9A, 9B. A brake that can be switched between an operation state and a non-operation state may be provided in each of drive transmission paths to the planetary gears 3A, 3B respectively corresponding to the motors 9A, 9B.SELECTED DRAWING: Figure 1

Description

The present invention relates to a drive device, a robot and an image forming device.

Conventionally, a drive device, a robot, and an image forming device in which the same output shaft is rotated by two motors for the purpose of suppressing backlash are known. For example, in Patent Document 1, backlash is suppressed by a drive mechanism having a reduction mechanism in which each drive transmission system from each motor to the output shaft is composed of a plurality of external gears, and the drive torque of the drive target is improved. A drive device that is compact and compact is described.

However, in a drive device in which the same output shaft is rotated by two motors for the purpose of suppressing backlash, the reliability of gears close to the output shaft on the drive transmission system path is further improved in terms of wear resistance and strength. desired.

In order to solve the above problems, the present invention has two drive devices that rotate the same output shaft by two motors so that the external gear and the carrier are shared and the planetary gear and the sun gear are dedicated. It is characterized by constructing a planetary type planetary gear mechanism.

According to the present invention, it is possible to improve the wear resistance and strength of the gear close to the output shaft on the drive transmission system path.

The explanatory view of the drive device 1 which concerns on Embodiment 1. FIG. Explanatory drawing of backlashless state at the time of hold. Explanatory drawing of the state at the time of rotation in the CW direction in the backlashless state. The schematic block diagram of the drive device which concerns on a comparative example. The block diagram of the control board 210 described in Patent Document 1. The graph which shows the specific example of the offset control by the position / speed control unit 213. The external view of the drive device 100 which concerns on Embodiment 2. The front view which shows the schematic structure of the "first drive transmission system" and "second drive transmission system" of a drive device 100. A cross-sectional view taken along the line AA of the drive device 100 shown in FIG. An enlarged view of the planetary gear portion in FIG. FIG. 9 is an enlarged view of the first brake mechanism 140 portion in FIG. The figure which shows the schematic structure of the robot which concerns on this Embodiment 3. Cross-sectional view of the part of the robot. FIG. 13 is an enlarged cross-sectional view of part A circled in FIG. The schematic block diagram of the image forming apparatus which concerns on Embodiment 4.

[Embodiment 1]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1A and 1B are explanatory views of a drive device 1 according to a first embodiment, where FIG. 1A is a perspective view and FIG. 1B is a partial cross section. This drive device 1 uses a planetary type planetary gear mechanism to eliminate backlash of the output shaft with two motors. Specifically, it is provided with one output shaft (planetary carrier) 2, two systems of planetary gears 3A and 3B, sun gears 4A and 4B, and one fixed outer ring gear (internal gear) 5. It has a backlash reduction mechanism.

The planetary gears 3A and 3B of each of the two systems are inserted into the same carrier pin 6 and can rotate freely, and mesh with the outer ring gear 5 which is the same (common) as the sun gears 4A and 4B, respectively. Further, the sun gears 4A and 4B of the two systems are coupled to the input gears 8A and 8B (first input gear and second input gear) via the input shafts 7A and 7B, respectively. One input shaft 7A and the other input shaft 7B arranged inside the input shaft 7A can rotate freely. The input gears 8A and 8B are rotationally driven from the motors 9A and 9B, respectively, via drive transmission systems (drive transmission paths) 10A and 10B, if necessary. The motors 9A and 9B are controlled by the control unit 11.

FIG. 2 is an explanatory diagram of a backlashless state at the time of holding. The meshing part with the outer ring gear 5 is a fulcrum, the meshing part with the sun gears 4A and 4B is the point of effort, the insertion part of the planet carrier pin 6 is the point of action, and the sun gear 4A is counterclockwise (CCW) indicated by the solid arrow. The sun gear 4B is applied with equal torque in different directions, which are clockwise directions (CW) indicated by broken arrows.

The planetary gear 3A that meshes with the sun gear 4A that rotates in the CCW direction generates torque in the direction that rotates (revolves) the planet carrier pin 6 in the CCW direction. On the other hand, the planetary gear 3B that meshes with the sun gear 4B that rotates in the CW direction generates torque in the direction that rotates (revolves) the planet carrier pin 6 in the CW direction. At this time, the planetary gear 3A rotates in the CW direction and the planetary gear 3B rotates in the CCW direction in contact with the outer ring gear 5. Similarly, the planetary gear 3A rotates in the CW direction with respect to the sun gear 4A, and the planetary gear 3B rotates in the CCW direction with respect to the sun gear 4B. Therefore, the backlash of the gear does not occur. The planet carrier pin 6 is coupled to the output shaft 2, and is held by the output shaft 2 without play by maintaining the balance of torque.

FIG. 3 is an explanatory diagram of a state when rotating in the CW direction in a backlashless state. In the hold state shown in FIG. 2, the torque of the sun gear 4B rotating in the CW direction indicated by the broken line arrow is increased. As a result, the balance of the forces on the planet carrier pin 6 is lost, and the output shaft 2 rotates in the CW direction without play. Contrary to FIG. 3, if the torque of the sun gear 4A rotating in the CCW direction indicated by the solid arrow is increased, the output shaft 2 rotates in the CCW direction without play.

FIG. 4 is a schematic configuration diagram of a drive device according to a comparative example. This device is different from the drive device of the first embodiment in that the two drive transmission systems from the motors 9A and 9B are up to the sun gears 4A and 4B, and the same planetary gear 12 is used. In this drive device, by rotating the sun gears 4A and 4B in opposite directions, backlash up to the planetary gears 12 can be controlled without causing backlash of the gears until they mesh with the same planetary gears 12. However, there remains some play in the meshing between the planetary gear 12 and the outer ring gear 5. As a result, it is not possible to loosen the gears up to the output shaft 2.

The control unit 11 controls the motors 9A and 9B so as to establish the hold state of FIG. 2, the CW direction rotation state of FIG. 3, or the CCW direction rotation state opposite to that of FIG. As a specific example of the configuration of the control unit 11 and the method of controlling the control unit 11, the control board 210 and the specific example of offset control described in Patent Document 1 can be used.

FIG. 5 is a configuration diagram of the control board 210 described in Patent Document 1. The control board 210 includes a position / speed control unit 213, a driver 223, and a driver 224. The first motor 101 has an encoder 101B. The encoder 101B is provided on the drive shaft 101A of the first motor 101, and outputs the encoder signal enc1 of the first motor 101. The encoder signal enc1 is supplied to the position / speed control unit 213 of the control board 210, and is used by the position / speed control unit 213 for PID (Proportional Integral Differential) control of the position and speed of the first motor 101.

The second motor 151 has an encoder 151B. The encoder 151B is provided on the drive shaft 151A of the second motor 151, and outputs the encoder signal enc2 of the second motor 151. The encoder signal enc2 is supplied to the position / speed control unit 213 of the control board 210, and is used by the position / speed control unit 213 for PID control of the position and speed of the second motor 151. The first motor 101 and the second motor 151 correspond to the motors 9A and 9B, respectively.

The position / speed control unit 213 controls the PID of the first motor 101 based on the position target value xtgt and the speed target value vtgt input from the host controller and the encoder signal enc1 of the first motor 101 output from the encoder 101B. I do. The driver 223 generates a drive signal of the first motor 101 (a drive signal according to the motor form such as a DC motor or a DC brushless motor) according to the input voltage command value drvout, and uses the drive signal as the first motor. Output to 101.

Further, the position / speed control unit 213 is based on the position target value xtgt and the speed target value vtgt input from the host controller and the encoder signal enc2 of the second motor 151 output from the encoder 151B, and the second motor 151. PID control is performed. The driver 224 generates a drive signal for the second motor 151 (a drive signal according to the motor form such as a DC motor or a DC brushless motor) according to the input voltage command value drvout, and generates the drive signal for the second motor. Output to 151.

The position / speed control unit 213 performs offset control for controlling the voltage command values of the first motor 101 and the second motor 151, thereby causing backlash between these two motors 101 and 151 and the output gear 108. These two motors 101 and 151 can be driven while solving the above problems.

FIG. 6 is a graph showing a specific example of offset control by the position / speed control unit 213. The horizontal axis represents the input voltage command value drvin before control by offset control, and the vertical axis represents the output voltage command value drvout after control by offset control. The solid line represents the voltage command value of the first motor 101, and the dotted line represents the voltage command value of the second motor 151.

First, as shown in A in the figure, the position / speed control unit 213 applies an offset voltage offset for driving the output gear 108 in the direction opposite to the driving direction to the first motor 101. The voltage command value (offset voltage command value) of 101 is output. In that state, the position / speed control unit 213 gradually applies a drive voltage for driving the output gear 108 in the drive direction while applying a voltage having the same value as the absolute value of the offset voltage offset to the second motor 151. In addition, the voltage command value of the second motor 151 is controlled. As a result, driving forces in opposite directions are applied to the output gear 108 from both the two motors 101 and 151, so that the backlash between the output gear 108 and the two motors 101 and 151 is eliminated. It becomes.

Next, as shown in B in the figure, the position / speed control unit 213 is in a state where the drive voltage drvlimit is applied to the second motor 151 when the output of the second motor 151 reaches the limit value in the drive voltage drvlimit. The voltage command value of the second motor 151 is controlled so as to maintain. In that state, the position / speed control unit 213 controls the voltage command value of the first motor 101 so that the drive voltage for driving the output gear 108 in the drive direction is gradually applied to the first motor 101. As a result, driving forces in the same direction are applied to the output gear 108 from both of the two motors 101 and 151, so that the driving torque of the output gear 108 can be increased. That is, the drive torque of the drive target can be improved. At this time, it is preferable to raise the drive voltage of the first motor 101 at the same rate of increase as when the drive voltage of the second motor 151 is increased in A in the figure.

Then, as shown in C in the figure, the position / speed control unit 213 transfers the output of both the two motors 101 and 151 to both of the two motors 101 and 151 at the drive voltage drvrimit. Therefore, the voltage command values of the two motors 101 and 151 are controlled so as to maintain the state in which the drive voltage drvrimit is applied.

In the example of FIG. 6, A'to C'in the figure represents an example of driving each motor in the direction opposite to A to C in the figure, and is symmetrical with A to C in the figure.

As described above, in the drive device 1 of the first embodiment, the closer the gear is to the output shaft (planetary carrier) 2, the larger the torque is transmitted, so that the force applied to the tooth surface of the gear becomes larger. By using the planetary gear mechanism, the transmission torque from the first motor 9A is distributed by the plurality of planetary gears 3A, and similarly, the transmission torque of the second motor 9B is distributed by the plurality of planetary gears 3B. Since the transmission torque can be distributed to the planetary gears 3A and 3B in this way, the force applied to the tooth surface can be reduced, which improves reliability.

Further, in the drive device 1, the rotation speed of the output shaft (planetary carrier) 2 is the gear in the drive transmission system provided as necessary with respect to the rotation speed of the motors 9A and 9B, and the sun gears 4A and 4B and the planet. It is decelerated by a reduction mechanism including gears 3A and 3B. Therefore, by adjusting the number of teeth of these gears and adjusting the reduction ratio, the rotation speed of the output shaft (planetary carrier) 2 can be reduced to a desired rotation speed.

Instead of using the carrier pins 6 in the two planetary gears 3A and 3B, dedicated pins may be provided for each and integrated with one output shaft (planetary carrier) 2 by press fitting or the like. Further, the gears of the motor shaft and the drive transmission systems 10A and 10B provided as needed can be configured by using the gears and spur gears. It is desirable to use a Hasuba gear as the gear of the motor shaft and the gear that meshes with the gear. Vibration and noise can be reduced by using Hasuba gears.

[Embodiment 2]
Next, the drive device 100 according to another embodiment of the present invention (Embodiment 2) will be described. The drive device 100 specifies a more specific configuration of the drive device 1 of the first embodiment and adopts a configuration suitable for being applied to a robot.

7A and 7B are external views, FIG. 7A is a front view, and FIG. 7B is a right side view. The housing 120 includes a front housing 121 and a rear housing 122. The output flange 109 is exposed from the opening formed in the front housing 121. A first brake mechanism 140 and a second brake mechanism 190 are attached to the front surface of the front housing 121. The first motor 101 and the second motor 151 are attached to the back side of the rear housing 122. The housing 120 is also formed with a plurality of fixing holes 120A for fixing the drive device 100 to another device. The housing 120 is provided with a "first drive transmission system" and a "second drive transmission system" for transmitting rotational force from each of the first motor 101 and the second motor 151 to the output flange 109.

FIG. 8 is a front view showing a schematic configuration of a “first drive transmission system” and a “second drive transmission system” of the drive device 100. The first drive transmission system includes a first first pinion shaft 102, a first first gear 103, a first second pinion shaft 104, a first second gear 105, a first sun pinion shaft 307, a first third gear 308, and a plurality of first planets. A gear 310 is provided. Similarly, the second drive transmission system also has a second first pinion shaft 152, a second first gear 153, a second second pinion shaft 154, a second second gear 155, a second sun pinion shaft 357, a second third gear 358, and a plurality of gears. It includes a second planetary gear 360.

FIG. 9 is a sectional view taken along the line AA of the drive device 100 shown in FIG. FIG. 10 is an enlarged view of the planetary gear portion in FIG. The first first pinion shaft 102 and the second first pinion shaft 152 each have bearings 131 and 181 fixed to the front housing 121 and bearings 132 and 182 fixed to the rear housing 122, and both ends are rotatable. It is supported. The first first gear 103 and the second first gear 153 are press-fitted into the first first pinion shaft 102 and the second first pinion shaft 152, respectively, at the same speed as the pinion shaft without idling with respect to these pinion shafts. Rotate. The first first gear 103 and the second first gear 153 rotate by transmitting the rotational force from the drive shaft by engaging with the gears formed on the drive shafts 101A and 151A of the first motor 101 and the second motor 151. ..

The first and second first pinion shafts 102 and 152 penetrate the front housing 121 and extend to the front of the front housing 121, and the first and second brake mechanisms 140 extend to the extending portion. , 180 are provided. Details of these brake mechanisms will be described later.

The first and second second pinion shafts 104 and 154 include two bearings 133, 134, 183 and 184 fixed inside the pinion shaft, and shafts 104A fixed to the front housing 121 and the rear housing 122. Both ends are rotatably supported by the 154A (see FIG. 10). The first and second second gears 104 and 155 are press-fitted into the first and second second pinion shafts 104 and 154, respectively, and rotate at the same speed as the pinion shaft without idling with respect to these pinion shafts. To do. The first and second second gears 105 and 155 engage with the gears formed on the first and second first pinion shafts 102 and 152, respectively, from the first and second first pinion shafts 102 and 152. The rotational force of is transmitted and rotates. The first and second second pinion shafts 154 may be rotatably held by bearings fixed to the housing 120.

In the planetary gear portion shown in FIG. 10, the output flange 109 is rotatably provided by a bearing 117 fixed to the front housing 121. The second sun pinion shaft 357 is provided coaxially with the output flange 109. Both ends of the second sun pinion shaft 357 are rotatably supported by a bearing 135 fixed to the output flange 109 and a bearing 136 fixed to the rear housing 122. The first sun pinion shaft 307 has a tubular shape, and is rotatably arranged on the outer circumference of the second sun pinion shaft 357. Further, the second sun pinion shaft 357 has a tubular shape, and a sensor pipe 106 is provided so as to penetrate the inside of the cylinder.

The upper end of the sensor pipe 106 is press-fitted into a through hole formed in the center of the output flange 109. As a result, the sensor pipe 106 rotates at a constant speed with the output flange 109. On the other hand, the lower end portion of the sensor pipe 106 penetrates the opening formed in the rear housing 122 and is exposed from the opening.

A hollow permanent magnet 106A is fixed to the lower end of the sensor pipe 106. The hole IC 119 of the angle sensor is provided at a position on the substrate 118 facing the permanent magnet 106A. A magnetic encoder is configured by these, and the hall IC 119 detects the switching between the S pole and the N pole of the permanent magnet due to the rotation of the sensor pipe 106, thereby rotating the rotation angle of the sensor pipe 106 (that is, the rotation of the output flange 109). Corner) can be detected

The first third gear 308 is press-fitted into the first sun pinion shaft 307 and rotates at a constant speed with the first sun pinion shaft 307 without idling with respect to the first sun pinion shaft 307. The first third gear 308 meshes with the gear formed on the first second pinion shaft 104, so that the rotational force from the first second pinion shaft 104 is transmitted to rotate the first third gear 308.

The second third gear 358 is fastened to the second sun pinion shaft 357 by a power transmission element such as a key 358A, and has a constant velocity with the second sun pinion shaft 357 without idling with respect to the second sun pinion shaft 357. Rotate with. The second third gear 358 rotates by transmitting the rotational force from the second second pinion shaft 154 by meshing with the gear formed on the second second pinion shaft 154.

The key 358A is fixed with a screw 358B in order to prevent the second third gear 358 and the second sun pinion shaft 357 from moving in the thrust direction. The reason for using the key 358A for power transmission is to ensure ease of assembly.

The rotations of the first and second sun pinion shafts 307 and 357 are transmitted to the output flange 109 via the plurality of planetary gears 310 and 360. Specifically, the first and second solar gears 307A and 357A are formed on a part of the first and second solar pinion shafts 307 and 357, respectively. The first sun gear 307A rotates the plurality of first planetary gears 310 by meshing with each of the plurality of first planetary gears 310 arranged around the sun gear. Further, the second solar gear 357A rotates the plurality of second planetary gears 360 by meshing with each of the plurality of second planetary gears 360 arranged around the sun gear.

The sliding bearings of the first and second planetary gears 310 and 360 are press-fitted into the through holes formed in the center. The sliding bearing is provided with a shaft pin 112, which is a rotation shaft of the first and second planetary gears 310, 360, penetrating through a through hole formed in the center. As a result, the first and second planetary gears 360 are rotatable with respect to one shaft pin 112 via the sliding bearing.

The first sun gear 307A must be engaged with the first planetary gear 310, and the second sun gear 357A must be engaged with the second planetary gear 360 (for example, the first sun gear 307A has the second planetary gear 360). It should not be in a state of meshing). In FIG. 8, four first and second planetary gears 360 are arranged, but two or more may be used.

The front end of the shaft pin 112 in the drawing is press-fitted into the output flange 109, and the rear end of the shaft pin 112 in the drawing is press-fitted into the hub ring 113. This regulates the axial movement of the planetary gears. By connecting a plurality of shaft pins 112 (four in the illustrated example) with the hub ring 113, it is possible to prevent the shaft pins 112 from being deformed by the force generated by the meshing of the gears. The hub ring 113 is held by the output flange 109 via the shaft pin 112. In addition to this, it may be held on the peripheral surface of the first sun pinion shaft 307 via a bearing or a sliding bearing. The shaft pins 112 (planetary carrier pins) that serve as the rotation axes of the first and second planetary gears 310 and 360 are also used by the first and second planetary gears 310 and 360, but they are dedicated pins, respectively. May be provided and integrated with the output flange 109 by press fitting or the like.

Internal gears (outer ring gears) 116 are formed around the plurality of first and second planetary gears 310 and 360. Each of the plurality of first and second planetary gears 310 and 360 meshes with the first and second sun gears 307A and 357A, respectively, and also meshes with the internal gear 116. Therefore, when the first and second sun gears 307A and 357A rotate, the plurality of first and second planetary gears 310 and 360 rotate around the first and second sun gears 307A and 357A while rotating. Revolve. The rotational force due to the revolution of the plurality of first and second planetary gears 310 and 360 causes the output flange 109 to rotate via the shaft pins 112 of the plurality of first and second planetary gears 310 and 360. The rotation of the output flange 109 is transmitted to a drive target (for example, a joint of a robot) coupled to the output flange 109, whereby the drive target is driven.

FIG. 11 is an enlarged view of the first brake mechanism 140 portion in FIG. Since the second brake mechanism 190 has the same configuration, the first brake mechanism 140 will be described as an example. As shown in FIG. 11, the brake mechanism 140 is provided coaxially with the first first pinion shaft 102. Since the drive device 100 constitutes a drive transmission system using a plurality of gears, the transmission efficiency when transmitting the rotational force of the first motor 101 to the output flange 109 is relatively high (about 90%), while Therefore, the rotational force of the output flange 109 also has a characteristic of being easily transmitted to the motor 101.

Therefore, for example, when the drive device 100 of the present embodiment is attached to the robot arm, if the drive of the motor 101 is stopped and the motor 101 does not hold the rotation of the rotation axis of the robot arm, the robot arm itself Its own weight is transmitted to the output flange 109 as a moment. This moment causes the robot arm to automatically descend to a balanced position with gravity.

Therefore, in the drive device 100 of the present embodiment, the rotation of the drive transmission system is mechanically braked by the brake mechanism 140, so that the motor 101 does not hold the rotation of the rotation shaft of the robot arm. , It is possible to avoid the situation where the robot arm is automatically lowered. This brake mechanism 140 corresponds to a brake that can be switched between operation and non-operation.

As shown in FIG. 8, the brake mechanism 140 includes a brake cover 141, a rotor hub 142, a brake body 143, a screw 144, a rotor 145, an armature 146, a plate 147, and a coil 148.

A part of the first first pinion shaft 102 projects from the front surface of the front housing 121 to the inside of the brake cover 141. In the illustrated example, an O-ring 102A is attached to the outer peripheral surface of the first first pinion shaft 102. Since the O-ring 102A is in close contact with the inside of the bearing 131, it is possible to prevent grease from leaking from between the first first pinion shaft and the bearing 131.

Inside the brake cover 141, a rotor hub 142 is attached to the tip of the first pinion shaft 102. The rotor hub 142 has a structure that rotates together with the first pinion shaft 102 by a pin or a D cut, and is fixed to the tip of the first pinion shaft 102 by a retaining screw 144.

The rotor hub 142 is square so as to mesh with the rotor 145 inside the brake body 143. When the first pinion shaft 102 rotates, the rotation is transmitted to the rotor 145 inside the brake body 143 via the rotor hub 142, and the rotor 145 rotates.

At the time of braking, the armature 146 is pushed downward by the urging force from the spring (not shown). As a result, the rotor 145 is sandwiched between the armature 146 and the plate 147, and the frictional force generated at that time brakes the rotation of the rotor 145.

On the other hand, when non-braking, the coil 148 is energized, and the armature 146 is attracted upward by a magnetic attraction force larger than the urging force generated between the coil 148 and the armature 146. As a result, the rotor 145 is released from the frictional force and becomes rotatable.

Also in the drive device 100 of the second embodiment, the first and second motors 101 and 151 are controlled by using the control means. As a specific example of the configuration of the control means and the method of controlling the control means, the control board 210 and the offset control described with reference to FIGS. 5 and 6 can be used. That is, in order to eliminate the backlash, the first motor 101 is rotated in the normal direction to rotate the output gear. At this time, the second motor 151101 rotates while braking the output gear (preload torque). As a result, the play in the forward / reverse direction of the output gear can be eliminated.

Further, by operating the first and second motors 151101 in a coordinated manner, for example, if the power of the first and second motors 151101 is 20 W each, it is possible to obtain a power of about 40 W on the output shaft.

As described above, in the drive device 100 of the second embodiment, the first and second motors 101 and 151 that generate the rotational force, and the rotational force generated by the motors are decelerated to obtain the desired rotation speed and torque from the output flange 109. The drive transmission system and the first and second brake mechanisms 140 and 180 for braking the rotation in the drive transmission system are integrally provided with respect to the housing 120. The housing 120 has a box shape by fastening the front housing 121 and the rear housing 122 case with screws. As a result, the drive device 100 can increase the torsional rigidity when torque is generated, suppress a decrease in meshing accuracy between the gears, and suppress a rotational load of the gears.

Further, in the drive device 100, the motor, the drive transmission system, the sensor system, the controller system, and the brake mechanism are integrated into the housing 120 and modularized. Therefore, for example, when the drive device 100 is installed in the robot arm, the housing 120 is simply attached to the robot structure, and the rotation shaft on the robot side and the output shaft (output flange 109) of the drive device 100 are fixed. The installation of the drive device 100 can be completed. Therefore, it can be said that the drive device 100 is extremely easy to attach / detach during maintenance.

Further, the rotational force of the output flange 109 is transmitted to a device that utilizes the rotational force. For example, when the rotational force of the output flange 109 is used for the rotation of the robot arm, the robot arm can be rotated by connecting the output flange 109 to the rotation axis of the joint of the robot arm. At this time, by fitting the pin 109B protruding from the surface of the output flange 109 into the rotation shaft of the joint of the robot arm, the rotation shaft can be aligned and non-slip.

Further, the upper controller can calculate the operating angle of the robot arm from the rotation angle of the drive shaft detected by the encoder (rotation angle detection sensor) provided inside the motor. That is, the upper controller can set the operating angle of the robot arm to a desired angle by controlling the rotation angle of the drive shaft based on the output value of the encoder. Then, in order to detect the operating angle of the robot arm more accurately, the signal of the angle sensor (106A, 119) that detects the rotation angle of the output flange 109 can also be used.

Further, since the sensor pipe 106 at the center of the sun gear pinion shafts 307 and 305 penetrates from the front surface of the front housing 121 to the back surface of the rear housing 122, a harness is provided in the sensor pipe 106 when used for a robot, for example. The output flange 109 can be rotated while passing through the 740.

Since the drive device 100 of the second embodiment includes the first and second brake mechanisms 140, 180 and the like, it is suitable for a drive device that constitutes a joint portion of a robot arm and targets the arm body as a drive target. , The application target is not limited to this. If it is not necessary for the application target, the first and second brake mechanisms 140 and 180, the angle sensor (106A, 119), and the like can be omitted.

[Embodiment 3]
Next, an embodiment (Embodiment 3) of the robot provided with the drive device of the present invention will be described. FIG. 12 is a diagram showing a schematic configuration of a manipulator device 700, which is a robot according to the third embodiment. This manipulator device 700 is a two-degree-of-freedom manipulator device having two joints, and is used by mounting it on a rotating stage or the like. It has a first arm 701 and a second arm 702, and is provided with a picking hand 703 as an end effector at the tip of the second arm 702. The base end of the first arm 701 is rotatably attached to the upper end of the support 705 fixed to the upper part of the pedestal 704. The first joint portion 706 is formed by both attachment portions. The base end of the second arm 702 is rotatably attached to the tip of the first arm 701, and the attachment portions of both form the second joint portion 707.

FIG. 13 is a cross-sectional view of a portion constituting the first joint portion 706. As a drive device for driving the arm body 701A, which is the main body of the first arm 701, the drive device 100 according to the second embodiment is fixed to the support 705 and used. The arm body 701A is rotatably attached to the support 705 by a bearing 705A via an integrated rotary shaft member 701B. The drive device 100 is arranged inside the support 705 so that the rotation axis of the output flange 109 coincides with the rotation axis 730L of the arm body 701A. In this arrangement, the drive device 100 is provided with the support 705 by fitting the positioning pin 712 protruding from the inner surface of the support 705 into the recess 120B (see FIG. 7A) formed on the front surface of the front housing 121. It is possible to easily position the rotation angle with respect to. Then, the drive device 100 is fixed to the inner surface of the support 705 by a plurality of fixing screws 731. As shown in FIG. 7, holes 120A for fixing by the fixing screws 731 are provided at three places, for example.

FIG. 14 is an enlarged cross-sectional view of a portion A surrounded by a circle in FIG. The output flange 109 is fixed to the rotating shaft member 701B on the inner surface of the arm body 701A by a plurality of fixing screws 732. Specifically, a concave portion provided in the center of the output flange 109 is fitted into a convex portion formed on the inner surface of the rotating shaft member 701B of the arm body 701A, and the rotation center thereof is positioned. Then, the pin 109B protruding from the surface of the output flange 109 is fitted into the recess formed on the inner surface of the rotating shaft member 701B of the arm body 701A to position the rotation angle of the output flange 109 and prevent slipping. As a result, when the output flange 109 rotates, the arm body 701A fixed to the output flange 109 rotates.

The output flange 109 has a hollow shape due to the sensor pipe 106. The arm rotation shaft member 701B and the arm body 701A fixed to the output flange 109 are also provided with hollow portions corresponding to their positions. This makes it possible to pass the harness 740 as shown in FIG.

Also in the drive control of the arm main body 701A by the drive device 100, the control board 210 and the offset control described with reference to FIGS. 5 and 6 can be used as specific examples of the configuration of the control means and the control method thereof. The control of the rotation direction and the rotation amount (rotation angle) of the arm body 701A controls the rotation direction and the rotation amount (rotation angle) of the motor from the upper controller. As a result, the rotation of the arm body 701A can be controlled by controlling the first and second motors 101 and 151 from the upper controller while making the rotation of the arm body 701A brakeable by the brake mechanism. Further, by controlling the brake mechanism from the upper controller, the rotation of the arm body 701A can be braked.

The above configuration of the first joint portion 706 described with reference to FIGS. 13 and 14 can also be applied to the second joint portion 707. That is, the drive device 100 can be attached to the first arm 701, and the output flange 109 can be fixed to the second arm 702 to drive the second arm 702 as a drive target.

Further, as shown in FIGS. 13 and 14, if the robot is provided with such a joint portion, not only the robot but also an industrial robot, a household robot, or the like can be used as long as the robot has such a joint portion. Robots for various purposes equipped with arms can be targeted.

[Embodiment 4]
Next, an embodiment (Embodiment 4) of the image forming apparatus including the driving device of the present invention will be described. FIG. 15 is a schematic configuration diagram of the image forming apparatus according to the fourth embodiment. The document D is transported (fed) in the direction of the arrow in the drawing by the document transport unit 810, passes over the document reading unit 802, and the image information is optically read by the document reading unit 802. The exposure light L such as a laser beam based on the read image information is irradiated from the exposure unit 803 (writing unit) onto the photoconductor drum 805 of the image forming unit 804. In the image forming unit 804, an image (toner image) corresponding to the image information is formed on the photoconductor drum 805 through a predetermined image forming process (charging step, exposure step, developing step). The formed image is transferred by the transfer unit 807 onto the sheet P transported from the feeding device 852 through the transport path K or the like. The toner image of the sheet P after the transfer step is fixed by the fixing device 820, and the sheet P is loaded on the paper ejection tray 831.

A plurality of feeding devices 812 and 813 are provided in the main body of the device 801. These have almost the same structure. The feeding device 813 is provided with a mounting portion 843 (elevating plate), a feeding device 852 as a feeding means for feeding the sheet P mounted on the mounting portion 843, and the like.

The image forming apparatus 801 configured in this way has a drive location (for example, paper feed transfer, document transfer, photoconductor drum 805) that requires positioning control that avoids the influence of backlash and control that improves the drive torque of the drive target. The drive device of the second embodiment is provided for at least one place (rotational drive, etc.). According to this, accurate positioning control can be performed.

1: Drive device 2: Output shaft 3A: Planetary gear 3B: Planetary gear 4A: Sun gear 4B: Sun gear 5: Outer ring gear 6: Planet carrier pin 7A: Input shaft 7B: Input shaft 8A: Input gear 8B: Input gear 9A : Motor 9B: Motor 10A: Drive transmission system 10B: Drive transmission system 11: Control unit 12: Planetary gear 100: Drive device 101: First motor 101A: Drive shaft 102: First first pinion shaft 102: First pinion shaft 103 : First first gear 104: First second pinion shaft 105: First second gear 108: Output gear 109: Output flange 109B: Pin 112: Shaft pin 113: Hub ring 116: Internal gear 118: Board 119: Hall IC
120: Housing 121: Front housing 122: Rear housing 140: First brake mechanism 151: Second motor 152: Second first pinion shaft 153: Second first gear 154: Second second pinion shaft 155: Second second gear 190: Second brake mechanism 210: Control board 305: Sun gear pinion shaft 307: First sun pinion shaft 307A: First sun gear 308: First third gear 310: First planetary gear 357: Second sun pinion shaft 357A: Second sun Gear 358: Second third gear 360: Second planetary gear 700: Manipulator device 151: Second motor

JP-A-2018-204690

Claims (9)

In the drive device that rotates the same output shaft by two motors, two planetary type planetary gear mechanisms are configured so that the external gear and the carrier are shared and the planetary gear and the sun gear are dedicated, and each sun A drive device characterized in that the drive is transmitted to the gears from two motors. The drive device according to claim 1, further comprising a control means for performing control capable of reducing backlash by the two motors. The drive device according to claim 1 or 2, wherein a brake that can be switched between operation and non-operation is provided in each of the drive transmission paths from the two motors to the planetary gears corresponding to the respective motors. With the above two motors
The above two planetary planetary gear mechanisms and
A control means that controls backlash reduction by the above two motors, and
In the drive transmission path from the above two motors to the planetary gears corresponding to each motor, a brake that can be switched between operation and non-operation,
The driving device according to claim 1, further comprising an angle sensor for detecting the rotation angle of the carrier. The drive device according to any one of claims 1 to 4, wherein a reduction mechanism is provided between the two motors and each of the sun gears. The drive device according to claim 5, wherein the speed reduction mechanism includes a Hasuba gear. In a drive device having a first drive transmission system and a second drive transmission system for transmitting a rotational force from a motor to an output shaft and having a backlash reduction mechanism by two motors.
First and second motors, multiple first and second planetary gears, one internal gear, first sun gear and first input gear coupled to it, second sun gear and second input gear coupled to it, With a planetary gear mechanism consisting of
There are multiple first and second planetary gears, which are rotatably supported by carrier pins.
Each carrier pin is combined with one planetary carrier (output flange),
The first sun gear and multiple first planetary gears, and the second sun gear and multiple second planetary gears are arranged so as to mesh with each other.
Multiple first and second planetary gears mesh with one internal gear,
The first input gear can be driven by the first motor, and the second input gear can be driven by the second motor.
A drive device characterized by being A robot comprising the drive device according to any one of claims 1 to 7 and a drive target driven by the drive device. An image forming apparatus including the drive device according to any one of claims 1 to 7 and a drive target driven by the drive device.

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