JP2020148323A - Drive transmission device, driving device, and robot - Google Patents

Abstract

To provide a drive transmission device capable of realizing a state of providing compliance property by the drive transmission device, and suppressing cost increase in comparison with a case where a dedicated device is added.SOLUTION: A pair of gears 2A, B at a driving source side, and a common output-side gear 3 engaged with both of the pair of gears have such gear engagement that the pair of gears receive thrust force from the output-side gear. The pair of gears are supported movably in the axial direction, and elastic bodies 5A, B are disposed between members 21A, B for restricting the axial movement and the pair of gears, at axial sides different from each other in the pair of gears.SELECTED DRAWING: Figure 2

Description

The present invention relates to a drive transmission device, a drive device, and a robot.

Conventionally, it has been known to use a centering device, which is also called a compliance module or an error absorber, so that the robot hand at the tip of the robot arm can be switched between a state in which compliance is provided and a state in which rigidity is provided. There is. For example, Patent Document 1 discloses this kind of centering device.

In order to enable the robot hand and the like to be switched between a state in which compliance is provided and a state in which rigidity is provided, there is a problem that the cost increase is large if a conventional dedicated device is added.

In order to solve the above problems, in the drive transmission device of the present invention, a pair of gears on the drive source side and a common output side gear in which the pair of gears mesh with each other are provided, and the pair of gears are the gears on the output side. The pair of gears are engaged with gears that receive thrust thrust from the gears, and the pair of gears support the pair of gears so as to be movable in the axial direction, and the pair of gears regulate the movement in the axial direction on different axial sides. It is characterized in that an elastic body is provided between the gear and the gear.

According to the drive transmission device of the present invention, it is possible to realize a state in which compliance is provided by the drive transmission device, and it is possible to reduce the cost increase as compared with the case of adding a dedicated device.

The explanatory view of the schematic structure of the drive transmission device which concerns on Embodiment 1. FIG. Explanatory drawing when thrust thrust works on the bearing side. Explanatory drawing when thrust thrust works on the spring side. A graph showing the relationship between the magnitude of offset torque and compliance in backlash control. A block of a control unit according to the second embodiment. Explanatory drawing of one mode of backlash control. Explanatory drawing of control corresponding to FIG. Explanatory drawing of other modes of backlash control. Explanatory drawing of control corresponding to FIG. The block diagram according to the fourth embodiment. The figure which shows the schematic structure of the robot which concerns on this Embodiment 5. The external view of the drive device which concerns on a specific example. Sectional drawing of the part constituting the 1st joint part.

[Embodiment 1]
An embodiment in which the present invention is applied to a drive transmission device applicable to a drive device having a double motor control system will be described. 1A and 1B are explanatory views of a schematic configuration of a drive transmission device according to an embodiment, where FIG. 1A is a front view and FIG. 1B is a plan view. As shown in FIG. 1A, a pair of drive source side gears (hereinafter referred to as pinion gears) 2A and B and a common output side gear (hereinafter referred to as an output gear) 3 in which the pair of gears mesh with each other. Are in mesh. Each of the pinion gears 2A and B is rotationally driven by a motor. The pinion gears 2A and B and the output gear 3 are meshed with gears in which the pinion gears 2A and B receive thrust thrust from the output gear 3. Specifically, it is a combination of helical gears. In the illustrated example, the pinion gears 2A and B are twisted to the right and the output gear 3 is twisted to the left as shown in FIG. 2B.

The pinion gears 2A and B are movably supported in the axial direction. For example, the following support structure is adopted. The pinion gears 2A and B have shaft members 23A and B whose both ends are rotatably supported by the support plates 22A and B pairs via bearings 21A and B. The bearings 21A and B of the support plates 22A and B function as members that regulate the movement in the axial direction, and the interval G is larger than the width W of the pinion gears 2A and B so that a desired slide described later can be performed.

A guide groove extending in the axial direction is formed on the peripheral surfaces of the shaft members 23A and B, and a key member integrally protruding from the shaft holes of the pinion gears 2A and B enters the guide groove, and the key member guides into the groove. While doing so, the pinion gears 2A and B integrated with the key member can also move in the axial direction. This is an example, and other support structures may be adopted. The pinion gears 2A and 2B are provided with springs 5A and B as elastic bodies between the bearings 21A and B and 2 on different axial sides.

The springs 5A and 5B come into contact with the boss end faces of the pinion gears 2A and B, and elastically urge the pinion gears 2A and B to the bearing side on the opposite side in the axial direction to bring the other boss end face into contact with the bearing. Instead of directly contacting the other boss end face with the bearing, an elastic body having a different elastic modulus, for example, a spring that does not shrink at all may be inserted. It suffices if the ease of movement in the thrust direction can be made different. The material of the spring does not matter as long as it can exert an elastic force corresponding to the deformation as a spring against the movement of the pinion gears 2A and B in the thrust direction.

A drive device having a double motor control method performs backlash control and torque control. In backlash control, there are two ways of applying rotational torque to the pinion gears by the double motor (rotational drive direction of each pinion gear by the motor). .. Between these two ways, the direction of the thrust thrust applied to the pinion gears 2A and 2B by the output gear 3 is opposite.

FIG. 2 is an explanatory view when thrust thrust acts on the bearing side where springs 5A and B are not provided, and FIG. 3 shows thrust thrust acts on the bearing side where springs 5A and B are provided (hereinafter referred to as spring side). It is explanatory drawing of time. (A) is a front view and (b) is a plan view, respectively. For example, in FIG. 2B, the tooth streaks of the pinion gears (hereinafter referred to as pinion tooth streaks) that mesh with each other are shown by broken lines, and the tooth streaks of the output gear (hereinafter referred to as output tooth streaks) are shown by a solid line.

The circumferential component force of the load received by the pinion from the output gear that is the mating partner (hereinafter referred to as the circumferential load; the other component force is the radial load) is indicated by arrows f1A and B. The circumferential loads f1A and B are perpendicular to the tooth streaks and face from the pinion tooth streaks to the opposite side of the output tooth streaks that mesh with them. The axial component forces f2A and B are the thrust thrusts received by the pinion from the output gear, and in FIG. 2, the left pinion gear 2A is downward and the right pinion gear 2B is upward. In FIG. 3B, the directions are opposite.

As long as the teeth are in the meshing state of FIGS. 2 (a) and 3 (a), the thrust thrust directions shown in FIGS. 2 (b) and 3 (b) are oriented regardless of the cause of the state. For example, as shown in FIG. 2A, when each pinion is driven in the opposite direction, even when the torques of the pinions are equal and the output gear 3 is stopped, one of the torques is larger. , The meshing state of the teeth is the same when the other gear is driven and rotated via the output gear. Further, even when only one pinion gear is driven as shown in FIG. 2A and the other pinion gear is driven and rotated via the output gear 3 without being driven by the corresponding motor, the meshing state of the teeth is the same. is there.

Further, in addition to these, even when an external torque is applied to the output gear 3, as long as the teeth are in the meshing state shown in FIGS. 2 (a) and 3 (a), FIGS. 2 (b) and 3 (a) It is the direction of the thrust thrust shown in b). The hatching arrow f3 in FIG. 2A shows the counterclockwise torque from the outside, and the white arrow f4 shows the clockwise torque from the outside. FIG. 2B shows the increasing / decreasing directions of the circumferential loads f1 and f2 applied to the pinion tooth streaks when these torques are applied by hatching arrows f3A and f3B and solid white arrows f4A and f4B. Even if it increases or decreases in this way, the direction of thrust thrust does not change as long as the meshing state does not change.

As shown in FIG. 2, when thrust thrust acts on the bearing side without the springs 5A and B, both pinion gears 2A and B are attached to the bearings 21A and B without the springs 5A and B and cannot move. .. Since no deviation occurs in the thrust direction, there is no compliance (high rigidity). On the other hand, as shown in FIG. 3, when the thrust thrust toward the spring side is received, both pinion gears 2A and B can move while contracting and deforming the spring. Therefore, depending on the magnitude of the force, play occurs in the output shaft, resulting in a compliance (low rigidity) state. That is, compliance can be provided in the drive transmission system between the pinion and the output gear.

Backlashless control is possible even with gears such as spur gears that do not generate force in directions other than the direction of rotation, but helical gears generate force in the thrust direction when engaging. Therefore, if there is even a slight gap between the bearings, the gear will shift in the thrust direction when a force is applied to the gear. Due to this phenomenon, even if backlashless control is performed by the double motor, play is allowed in the output shaft, and desired positioning cannot be performed.

Generally, in order to prevent this, a thrust bearing is used to fix the shaft so that it does not shift in the thrust direction. However, in the present embodiment, this phenomenon is used to realize backlashless control and provide compliance. I did.

FIG. 4 is a graph showing the relationship between the magnitude of offset torque and compliance in backlash control. This is a case where backlash control is performed in the meshed state shown in FIG. The horizontal axis is the magnitude of the torque applied to the shaft of the output gear from the outside, and the vertical axis is the rotation angle of the output shaft when an external torque is applied as shown in f3 and f4 in FIG. The relationship between the two for each offset torque is shown. The relationship is almost straight, and the slope becomes the spring constant.

From this graph, it can be seen that the larger the offset torque, the larger the magnitude of the torque applied to the output shaft required to rotate the output rotation shaft. Further, even if the output shaft torque is such that the output rotation shaft can be rotated, it can be seen that the larger the offset torque, the smaller the rotation angle of the output shaft. Since the larger the output shaft rotation angle is, the better the compliance is, it can be seen that the degree of compliance can be changed by the offset torque. By changing the offset torque in this way, it is possible to change the output shaft load torque until compliance occurs in the output shaft. Therefore, it is possible to arbitrarily set the load torque required for compliance to occur in the output shaft.

As described above, according to the drive transmission device of the first embodiment, the pinion gear can be moved in the thrust direction to provide compliance, so that the cost increase can be reduced as compared with the case of adding a dedicated device. Moreover, the meshing state of the pinion gear and the output gear can be switched by the way the pinion gear is driven to switch the presence or absence of compliance (or low rigidity and high rigidity), and the meshing between the pinion gear and the output gear in which the pinion gear can move in the thrust direction. In the state, the degree of compliance (or low rigidity and high rigidity) can be switched by, for example, the offset voltage in backlash control. Furthermore, it becomes possible to have compliance from a one-stage gear configuration. Furthermore, because of the helical gear configuration, torque fluctuation is smaller than that of the spur gear configuration, and it is superior in quietness, durability, and controllability to the spur gear configuration.

[Embodiment 2]
Next, the drive device 100 according to another embodiment of the present invention (Embodiment 2) will be described. The drive device 100 includes the drive transmission device 1 of the first embodiment, motors 6A and B for the pinion gears 2A and B, and control units for the motors A and B. The target for driving by rotating the main shaft of the output gear 3 of the drive transmission device 1 includes, but is not limited to, a robot arm.

FIG. 5 is a block diagram of the control unit. The control unit includes a deviation calculation unit 7, a control controller 8, an offset control unit, and an output detector 10. Basically, it has the same configuration as the control unit in a drive device having a conventional double motor control system. Information on the target position, the target speed, or both of them is input to the deviation calculation unit 7 from the higher-level device as target information, and information on the rotation position and rotation speed of the output shaft is input from the output detector 10. The deviation information calculated from the deviation calculation unit 7 is input to the control controller 8. The control controller 8 calculates the drive amount according to the deviation, and outputs the drive voltage corresponding to the drive amount from the built-in PID control unit. The offset control unit 9 performs backlash control using the offset voltage and the like.

In the second embodiment, the double motor system and the pinion gears 2A and 2B are driven. As a result, for example, the tip of the arm that grips the work can be moved in the horizontal direction. The gear is provided with a backlash to rotate the gear smoothly. Backlash affects the accuracy of positioning the operating object and causes misalignment. Therefore, control for reducing backlash (backlashless control) is required.

In the backlashless control, as shown in FIGS. 6 (a) and 8 (a) when stationary, torque is applied in the opposite direction by setting the rotation direction of one of the gears 6A and 6B in the opposite direction. In this way, the gear teeth of the motors 6A and 6B and the gear teeth of the output shaft are firmly engaged with each other to prevent backlash.

At the time of rotation, assuming that the motor 6A rotates in the rotation direction, for example, by setting a drive voltage such that the output of the motor 6A exceeds the output of the motor 6B, both the motors 6A and 6B are in the rotation direction of the motor 6A. Although it rotates to, it meshes firmly with the gear teeth of the output shaft as when it is stationary, and there is no change in play.

Backlash can be reduced by performing the controls shown in FIGS. 6 (a) and 8 (a). This is because the teeth of the gears are immediately and firmly engaged with each other. However, in this control, only the torque of the difference between the motor 6A and the motor 6B can be applied to the output shaft.

Therefore, as shown in FIGS. 6 (b) and 8 (b), the motor that applies the torque opposite to the target rotation direction of the output shaft (in FIG. 6 (a), the motors 6A and 8 (a)). Then, the rotation direction of the motor 6B) is changed to the same direction as the other motor 6 that applies torque in the target rotation direction of the output shaft. This makes it possible to apply a torque exceeding the above difference to the output shaft.

In order to realize such control, an offset control unit 9 is provided as shown in FIG. The offset control unit 9 outputs a different mapping pattern predetermined for each motor by a look-up table or calculation to each of the motors 6A and 6B. Specifically, the offset control unit 9 determines each output value (drv_out) corresponding to the input value (drv_in) input by the control controller 8 based on the input or the preset parameter, and each determined output. The value is output to each of the motors 6A and 6B and set.

Parameters are used for the offset control unit 9. The parameters may be input each time, or may be preset in the offset control unit 9 and held by the offset control unit 9. Examples of the parameters include drvlimit (PWM limit), offset (PWM offset amount), lim_mod (without setting or with setting), offset_sel (offset pattern switching), offset_on (offset control presence / absence setting) and the like.

PWM (Pulse Width Modulation) is a method of controlling current and voltage by changing only the pulse width without changing the frequency. The drvrimit is a limit value (limit) of the output of the motor, and if there is no setting of lim_mod, it indicates that the drlvlimit is set as a limit, and if there is a setting, it indicates that the motor operates in cooperation with the drlvlimit or higher. The cooperative operation means that the same drive voltage is applied and the motors 6A and 6B are rotated in the same rotation direction and at the same rotation speed.

The offset is a voltage or the like that is set to apply torque in the opposite direction when starting the drive of the output shaft, and the voltage is called an offset voltage. The offset_on sets whether or not to control driving the output shaft by applying a driving voltage to the other motor while applying an offset voltage to one motor when starting the driving of the output shaft. Yes is 1 and no control is 0. When set without control, drv_out = drv_in, and the output of the controller is used as it is for driving the motor. The offset_sel selects the setting of the drv_out of the motor at the time of offset control, and the outputs of the drv_out of the offset_sel = 1 and the drv_out of the offset_sel = 0 are used for driving the respective motors. 0 and 1 are set as a pair.

When starting the drive of the output shaft, the offset control unit sets the offset voltage based on the parameter offset if the parameter is set to offset_on = 1. After starting to drive the output shaft, the offset control unit receives a control value given by the control controller 13 according to the operating condition of the motor shaft, that is, the position, speed, etc., obtained from the detection result detected by the output detector 10. Each corresponding output value is output with drv_in as an input value, and is set in each of the motors 6A and 6B.

Further, when the control controller 8 confirms the switching of the operation based on the detection result detected by the output detector 10, the control controller 8 or the offset control unit 9 drives the output shaft in the opposite direction to the final gear. Change the magnitude of the offset voltage.

The switching of the operation can be confirmed by whether or not the position or the like as the detection result has reached the completion position or the like of the predetermined operation. Whether or not the operation completion position or the like has been reached can be determined by whether or not the deviation has disappeared. In this judgment, a certain error range can be taken into consideration, and whether or not the deviation is within a certain range can be used as a judgment criterion.

Like the control controller 8, the offset control unit 9 also includes a processor and a memory, and the memory stores a program for causing the processor to execute a process of outputting each output value to each of the above motors 6A and 6B. be able to.

The process executed by the offset control unit 9 will be described in detail with reference to FIG. 7. FIG. 7 is a diagram corresponding to FIGS. 6A and 6B, showing the relationship between drv_in and drv_out when the parameter lim_mod is not set and offset control is performed with offset_on = 1. This setting is used when the drvrimit is set near the maximum PWM of the motor.

In FIG. 7, the vertical axis is the output value (drv_out) of the offset control unit 9, and the horizontal axis is the input value (drv_in) of the offset control unit 9.

When offset_on = 0 and offset control is not performed, the motors 6A and 6B are controlled by the same PWM and the same output value is output to the motors 6A and 6B as shown by the broken line. That is, the same drive voltage is applied to the motors 6A and 6B according to the input value from the control controller 8, the motors 6A and 6B are rotated in the same direction at the same rotation speed, and the same torque is applied to the output shaft. Call. From this, when offset control is not performed, the distribution of the drive voltage becomes even.

On the other hand, in the case of offset control with offset_on = 1, when the input value is a positive value and the value is small, when driving the output shaft, the drive voltages of the motors 6A and 6B are not made the same. , The motor 6A is provided with a constant offset voltage in the opposite direction. This is to apply a constant reverse torque. For the motor 6B, an extra voltage is added to the drive voltage according to the input value so as to cancel the offset voltage of the motor 6A (region (1) in FIG. 7). As a result, the output shaft is pushed from both sides with a constant torque, so backlash can be eliminated.

Further, the drive of the output shaft can be controlled by controlling the voltage added to the motor 6B.

When the input value increases in the positive direction and the drive voltage of the motor 6B reaches the limit, the offset voltage of the motor 6A, which has been given a constant offset voltage until then, is reduced to the same rotation direction as the motor 6B. Change to the drive voltage for driving (region (2) in FIG. 7). That is, the torque applied in the opposite direction is reduced. In the region (2), even when the motor 6A is in the same rotation direction as the motor 6B, torque is applied in the opposite direction due to the difference in rotation speed.

The slope indicating the rate of increase of the voltage given to the motor 6A when the torque applied in the reverse direction is reduced can be the same slope as the slope when an extra voltage is added to the motor 6B. Therefore, when the two drive voltages are added, the drive voltage has a double inclination until the limit is reached.

The input value at the start of reducing the offset voltage of the motor 6A when the drive voltage of the motor 6B reaches the limit uses the same input value limit and offset voltage (offset) as the output value limit, and (drvlimit). It can be −offset) / 2. Since the range of the input value in the area (2) is the range from (drvrimitte-offset) / 2 to the limit, the range is (drvrimit + offset) / 2.

When the input value becomes larger in the positive direction and the drive voltage applied to the motors 6A and 6B both reaches the limit, the output value becomes constant and a constant level voltage is applied (in FIG. 7, FIG. 7). Area (3)).

When controlling the drive of the output shaft, the input value may be not only a positive value but also a negative value. For example, there is a case where the target position is exceeded and the excess is returned. In this case, the control is the opposite of the control described above.

When the input value is small, when driving the output shaft, an offset voltage is given to the motor 6B, and an extra voltage is added to the drive voltage of the motor 6A to cancel the offset voltage of the motor 6B according to the input value. The voltage is set to the same voltage (region (4) in FIG. 7). When the input value increases in the negative direction and the drive voltage of the motor 6A reaches the limit, the offset voltage of the motor 6B, which has been given a constant offset voltage until then, is reduced to the same rotation direction as the motor 6A. Change to the drive voltage for driving (region (5) in FIG. 7). After the input value becomes larger in the negative direction and the drive voltage applied to the motors 6A and 6B reaches the limit, the output value becomes constant and a constant level voltage is applied (in FIG. 7). , (6) area).

In this way, the offset control unit 9 changes the voltage distribution method set in each of the motors 6A and 6B when performing offset control. That is, all of the input values are not distributed to equal voltages, but are distributed to different voltages according to the input values.

By the way, the offset voltage is used to move the backlash of the gear. It should be noted that no external load is applied only by this movement. Since it is only necessary to move the backlash amount, for example, a voltage of about 5% of the drive voltage up to the limit can be applied as the offset voltage. By applying an offset voltage of this degree, the effect of sufficiently reducing backlash can be obtained.

Although the process when lim_mod is not set has been described with reference to FIG. 7, the process may be performed when lim_mod is set. This setting is used when the drvrimit is set to a small value and it is desired to increase the torque more than the backlash control.

After the drive voltage applied to the motors 6A and 6B reaches the limit, the same PWM is used to control the regions (3) and (6). At this time, the same voltage is applied to the motors 6A and 6B, and the motors 6A and 6B are in a state of cooperative operation.

FIG. 9 corresponds to FIGS. 8A and 8B. Unlike FIG. 7, the drv_out with offset_sel = 1 is used to drive the motor 6A, and the output of the drv_out with offset_sel = 0 is used to drive the motor 6B.

Then, in the drive device 100 of the second embodiment, the mode without compliance and the mode with compliance are switched depending on whether the control of FIGS. 6 and 7 or the control of FIGS. 8 and 9 is performed. I have to.

Taking a robot arm as an example, consider a pick-and-place operation of a workpiece that requires insertion. It is expected that the positioning accuracy will be improved and the settling time will be shortened by increasing the rigidity and controllability by operating in the non-compliance mode during the approach and gripping operation of the workpiece. By operating in the compliance mode during the pulling out operation and the inserting operation, the rigidity is lowered, and even if the insertion / removal position is slightly deviated, the insertion / removal operation can be smoothly performed without imposing a load on the deceleration mechanism. ..

According to the second embodiment, in the drive device having the double motor control system, the speed reducer portion is made into a helical gear, an elastic body is incorporated between the shafts, and then the force applied to the output shaft is adjusted and its direction is adjusted. By switching, the high and low rigidity (compliance) can be easily switched without feedback control of the external force.

When switching between the modes of FIGS. 6 and 7 and the modes of FIGS. 8 and 9, the offset direction is switched, and the backlash region is always entered during the switching. At that time, there is a concern that play will occur in the output shaft and the position of the output shaft will shift. Therefore, at the time of switching, the position or speed is fed back by using an output detector 10 (see FIG. 5) such as an output shaft encoder.

Also, if the control voltage is suddenly switched, there is a concern that the two motors will suddenly operate and the output shaft will play, so the offset should be changed gently at a constant rate to switch modes. To do. After switching, return to normal control. By doing so, it is possible to switch the compliance mode without deteriorating the positioning accuracy even during operation.

[Embodiment 3]
Next, the drive device 100 according to another embodiment of the present invention (Embodiment 3) will be described. The drive device 100 is switched depending on whether the drive device 100 of the second embodiment controls the controls of FIGS. 6 and 7, while the thrust thrust in the direction of FIG. 2 is different. The double motor system is controlled only in the mode having the compliance shown in FIG. 8, the magnitude of the offset voltage is switched, and the backlash control is turned off. Others are the same as the drive device 100 of the second embodiment.

By switching the magnitude of the offset voltage, the same processing as in the second embodiment can be performed only in the compliance mode. That is, in a situation where a high load torque is not applied to the output shaft such as when the work is not held, good compliance can be obtained by changing the offset torque to a lower value. On the other hand, by increasing the offset torque during the approach and gripping operation of the work, it is possible to increase the load torque until compliance occurs and operate without reducing the positioning accuracy and the settling time.

By lowering the offset torque during the pulling-out operation and the inserting operation, the load torque until compliance occurs can be lowered, and the insertion / removal operation can be smoothly performed even if there is some misalignment.

The switching of compliance by switching the offset voltage can also be applied to the mode with compliance in the drive device of the second embodiment.

[Embodiment 4]
Next, the drive device 100 according to another embodiment of the present invention (Embodiment 4) will be described. The drive device 100 estimates the value of the load torque related to the output shaft. FIG. 10 is a block diagram thereof. The difference from the drive devices 100 of the second to third embodiments is that there are position detectors 61A and B such as encoders on the motors 6A and 6B sides, and the output is based on this and the output detector 10 such as the position of the output shaft. Estimate the value of the load torque related to the shaft.

In the compliance mode, when a load torque exceeding a certain level is applied to the output shaft due to the offset torque, the output shaft rotates and compliance occurs. There is a relationship as described with reference to FIG. 4 between this offset torque, the load torque related to the main shaft, and the amount of rotation of the output shaft. Since the elastic modulus of the spring 5 incorporated in the bearing of the pinion gear is fixed, it can be obtained and placed in advance. Therefore, by obtaining these relationships in advance through experiments, the torque applied by the amount of deviation between the rotation angle of the output shaft and the rotation angle of the motor when the load torque is applied to the main shaft and the output shaft rotates. The value of can be calculated.

Therefore, in the fourth embodiment, since the output shaft has position detectors 61A and B such as an encoder, the rotation angle of the output shaft and the rotation angle of the motor when the output shaft is rotated by applying a load torque to the main shaft. The amount of deviation of the angle is calculated by comparing. From this calculated deviation amount, it is possible to estimate the load torque applied to the output shaft in the compliance mode. Reference numeral 11 in FIG. 10 indicates an estimation unit. Using the estimated value 11a output from the estimation unit 11, when the estimated value exceeds the threshold value, control such as stopping the movement of the robot arm or switching to a drive that reduces the load torque related to the main shaft is performed. It can be carried out.

[Embodiment 5]
Next, an embodiment (embodiment 5) of the robot provided with the drive device of the present invention will be described. FIG. 11 is a diagram showing a schematic configuration of a manipulator device 700, which is a robot according to the fifth 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. The first joint portion 706 and the like are configured by using a specific example of the drive device 100 according to any one of the second to fourth embodiments.

12A and 12B are external views of the drive device 100 according to a specific example, where FIG. 12A is a front view and FIG. 12B 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. The output flange 109 is integrated with the shaft of the output gear 3 of the drive device 100. 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.

These motors 101 and 151 correspond to the motors 6A and B of the previous embodiment. The housing 120 is also formed with a plurality of fixing holes 120A for fixing the drive device 100 to another device. Then, the housing 120 is provided with a first drive transmission system and a second drive transmission system for decelerating from each of the first motor 101 and the second motor 151 and transmitting the rotational force to the output flange 109. The output flange 109 is integrated with the output shaft 2 in the drive device according to any one of the second to fourth embodiments.

FIG. 13 is a cross-sectional view of a portion constituting the first joint portion 706. The drive device 100 is fixed to the support 705 and used as a drive device for driving the arm body 701A, which is the main body of the first arm 701. 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 can easily position the rotation angle with respect to the support 705 by fitting the positioning pin 712 protruding from the inner surface of the support 705 into the recess formed on the front surface of the front housing 121. It has become like. Then, the drive device 100 is fixed to the inner surface of the support 705 by a plurality of fixing screws 731. Fixing with the fixing screw 731 is performed at, for example, three places.

In the drive control of the arm main body 701A by the drive device 100, the same offset control as that of the drive device 100 in any of the second to fourth embodiments can be used as a specific example 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. 12 and 13 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. 12 and 13, 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.

1: Drive transmission device 2: Output shaft 2A: Pinion gear 2B: Pinion gear 3: Output gear 5A: Spring 5B: Spring 6A: Motor 6B: Motor 7: Deviation calculation unit 8: Control controller 9: Offset control unit 10: Output detector 10: Detector 11: Estimator 11a: Estimated value 21A: Bearing 22A: Support plate 23A: Shaft member 54: Spring 61A: Position detector 100: Drive device 101: First motor 109: Output flange 120: Housing f1: Circle Circumferential load f1A: Circumferential load f2: Circumferential load f2A: Component force

Japanese Unexamined Patent Publication No. 2000-94377

Claims (9)

The pair of gears on the drive source side and the common output-side gear in which the pair of gears mesh with each other are meshed with the gears in which the pair of gears receive thrust thrust from the output-side gears. Is movably supported in the axial direction, and an elastic body is provided between the pair of gears and a member that regulates the movement in the axial direction on different axial sides of the pair of gears. Drive transmission device. The drive transmission device according to claim 1, wherein the pair of gears and the output side gear are helical gears. A drive device including the drive transmission device according to claim 1 or 2 and a drive source that gives drive to each of the pair of gears. The control unit of the drive source that performs backlash control for eliminating backlash between the output side gear and the pair of gears is provided, and the control unit has two backlash controls in which the directions of thrust thrusts are different from each other. The drive device according to claim 3, wherein the mode can be switched and controlled. The control unit of the drive source that performs backlash control for eliminating backlash between the output side gear and the pair of gears is provided, and the control unit is on the side where the thrust thrust is directed to the elastic body. The driving device according to claim 3, wherein the backlash is controlled so as to be. The driving device according to claim 4 or 5, wherein the backlash control in which the direction of the thrust thrust is the side on which the elastic body is provided includes two or more modes in which the thrust thrusts are different from each other. The drive device according to claim 4 or 5, further comprising a detector for detecting the rotation position or rotation speed of the gear on the output side. The drive device according to claim 7, further comprising an estimation unit that estimates torque related to the pair of gears based on the detection result of the detector. A robot including a drive device according to any one of claims 3 to 8 and a drive target driven by the drive device.

Images