ROBOT

A robot includes a motor, a speed reducer, a base, a first arm, a second arm, and an impeller operable to rotate together with the first arm or the speed reducer. The impeller is operable to rotate together with the first arm or the speed reducer and generate wind to cool the motor.

BACKGROUND

Technical Field

The present disclosure relates to a robot, and more particularly, it relates to a robot including a motor.

Background Art

Conventionally, a robot including a motor is known. Such a robot is disclosed in Japanese Patent Laid-Open No. 2017-226042, for example.

Japanese Patent Laid-Open No. 2017-226042 discloses a robot including a motor. The robot includes a base, a movable member, a speed reducer, and a cooling fan. The base is fixed to an installation surface. The movable member rotates with respect to the base. The speed reducer slows down rotation of the motor, and the movable member is rotated. The cooling fan is an electric fan. The cooling fan circulates a generated airflow along a surface of the motor.

SUMMARY

In the robot disclosed in Japanese Patent Laid-Open No. 2017-226042, the cooling fan is an electric fan, and thus wiring is required to drive the cooling fan, for example. Therefore, in the robot disclosed in Japanese Patent Laid-Open No. 2017-226042, the number of components of the robot such as wiring increases due to the use of an electric cooling fan to cool the motor, and the structure of the robot such as wiring routing is complex. Thus, in the robot disclosed in Japanese Patent Laid-Open No. 2017-226042, it is desired to reduce or prevent an increase in the number of components required to cool the motor and to reduce or prevent the complexity of the structure of the robot.

Accordingly, the present disclosure provides a robot capable of reducing or preventing an increase in the number of components required to cool a motor and reducing or preventing the complexity of the structure of the robot.

A robot according to an aspect of the present disclosure includes a motor, a speed reducer including an input operable to rotate by a driving force of the motor, a speed reduction portion to slow down and transmit rotation from the input, and an output operable to rotate by a driving force from the speed reduction portion, a base, a first arm relatively rotatably attached to the base to rotate by an output from the output of the speed reducer, a second arm relatively rotatably attached to the first arm, and an impeller operable to rotate together with the first arm or the speed reducer. The impeller is operable to rotate together with the first arm or the speed reducer and generate wind to cool the motor.

In the robot according to this aspect of the present disclosure, as described above, the impeller is operable to rotate together with the first arm or the speed reducer and generate wind to cool the motor. Accordingly, wiring or the like is not required to drive the impeller, and thus an increase in the number of components required to cool the motor and the complexity of the structure of the robot can be reduced or prevented.

In the robot according to this aspect, the impeller is preferably attached to the first arm to rotate together with the first arm or is preferably attached to the input of the speed reducer to rotate together with the input. Accordingly, the impeller can be rotated simply by attaching the impeller to the first arm or the input of the speed reducer, and thus a structure to rotate the impeller can be easily achieved.

In the robot according to this aspect, the impeller preferably includes a centrifugal impeller operable to rotate together with the first arm or an axial flow impeller operable to rotate together with the speed reducer. Accordingly, wind can be generated by rotating the centrifugal impeller together with the first arm or wind can be generated by rotating the axial flow impeller together with the speed reducer, and thus a structure to generate wind so as to cool the motor can be easily achieved.

In this case, the centrifugal impeller preferably surrounds the motor. Accordingly, wind can be evenly applied to the motor, and thus the motor can be effectively cooled.

In the robot including the centrifugal impeller surrounding the motor, the input preferably includes a hollow transmission shaft including a through-hole that penetrates in a direction in which a rotation axis of the input extends and operable to transmit the driving force from the motor to the speed reduction portion, and the centrifugal impeller is preferably operable to cool the speed reducer by rotating together with the first arm, generating wind, and causing generated wind to flow into the through-hole of the transmission shaft. Accordingly, not only the motor but also the speed reducer can be cooled, and thus an increase in temperature at a joint portion of the robot can be effectively reduced or prevented.

In the robot including the impeller including the centrifugal impeller or the axial flow impeller, the base is preferably attached to the speed reducer, the input preferably includes a hollow transmission shaft including a through-hole that penetrates in a direction in which a rotation axis of the input extends and operable to transmit the driving force from the motor to the speed reduction portion, and the axial flow impeller is preferably arranged in the through-hole of the transmission shaft. Accordingly, the speed reducer can be cooled from the inside by the wind generated by the axial flow impeller, and thus the speed reducer can be effectively cooled. Furthermore, the axial flow impeller is arranged in the through-hole of the transmission shaft such that the size of the axial flow impeller is sized to match the size of the through-hole, and thus the impeller can be downsized as compared with a case in which a centrifugal impeller arranged outside the through-hole of the transmission shaft is used.

The robot in which the axial flow impeller is arranged in the through-hole preferably further includes wiring connected to the motor, and an insertion tube into which the wiring is inserted is preferably arranged inside the axial flow impeller. Accordingly, unlike a case in which the wiring is placed outside the speed reducer, the wiring can be contained within the speed reducer, and thus exposure of the wiring can be reduced.

The robot in which the axial flow impeller is arranged in the through-hole preferably further includes a first joint that is a portion connecting the first arm to the base, and a second joint that is a portion connecting the first arm to the second arm. The motor is preferably attached to the base or the first arm while being arranged in an internal space of the base or an internal space of the first arm attached to a second joint side of the second arm, and the axial flow impeller is preferably operable to send wind to the motor arranged in the internal space of the base or the internal space of the first arm. Accordingly, even when the motor is arranged in the base or at the second joint, the axial flow impeller can apply wind to the motor, and thus the motor can be effectively cooled.

The robot in which the axial flow impeller is arranged in the through-hole preferably further includes a shaft cover to cover a motor side of the through-hole of the transmission shaft in the direction in which the rotation axis of the input extends, and the shaft cover preferably includes a speed reducer-side filter portion to remove foreign matter from air while allowing the air to flow from an external space of the base to an internal space of the base through the through-hole using wind of the axial flow impeller. Accordingly, while entry of foreign matter into the transmission shaft is reduced or prevented, wind can be sent to the external space of the base by the axial flow impeller. Thus, entry of foreign matter into the internal space of the base or the internal space of the first arm can be reduced or prevented, and the speed reducer and the motor can be cooled.

In the robot in which the axial flow impeller is arranged in the through-hole, the base preferably includes a base-side filter portion to allow an external space of the base and an internal space of the base to communicate with each other, and remove foreign matter from air while allowing the air to flow from the external space of the base to the internal space of the base. Accordingly, while entry of foreign matter into the base is reduced or prevented, wind can be sent from the internal space of the base to the external space by the axial flow impeller. Thus, entry of foreign matter into the internal space of the base or the internal space of the first arm can be reduced or prevented, and the speed reducer and the motor can be cooled.

In the robot according to this aspect, the impeller is preferably operable to rotate about a same axis as a rotation axis of the output of the speed reducer. Accordingly, the impeller can be prevented from rotating eccentrically, and thus rotation of the impeller can be stabilized.

In the robot according to this aspect, the impeller is preferably attached to the first arm, the first arm is preferably attached to the output of the speed reducer, and the impeller and the speed reducer are preferably connected to each other via the first arm in a heat conductive manner. Accordingly, not only the motor but also the speed reducer can be cooled by the impeller, and thus an increase in temperature at a joint portion of the robot can be effectively reduced or prevented.

The robot according to this aspect preferably further includes a motor holder to hold the motor in an air passage of the impeller. Accordingly, wind can be stably applied to the motor, and thus the motor can be effectively cooled.

In this case, the motor holder preferably includes a convex cooling fin arranged in the air passage. Accordingly, the motor can be cooled by the cooling fin of the motor holder, and thus the motor can be more effectively cooled.

The robot according to this aspect preferably further includes a first joint that is a portion connecting the first arm to the base, and a second joint that is a portion connecting the first arm to the second arm. The motor is preferably arranged in an external space of the base attached to the speed reducer or an external space of the first arm attached to a second joint side of the second arm. Accordingly, the motor can be cooled not only by the wind from the impeller but also by being exposed to outside air, and thus the motor can be effectively cooled.

In this case, the robot preferably further includes a motor cover to cover the motor and including a motor-side filter portion to remove foreign matter from air while allowing the air to flow from an internal space of the base to the external space of the base. Accordingly, adhesion of foreign matter to the motor can be reduced or prevented, and wind can be applied to the motor. Thus, the motor can be effectively cooled.

In the robot including the motor cover, the motor and the motor cover are preferably in direct contact with each other or in contact with each other via a thermal conductor. Accordingly, the heat of the motor can be released by the motor cover, and thus the motor can be effectively cooled.

In the robot according to this aspect, the impeller preferably includes a plate-shaped movable blade that is tilted in a first rotation direction of the impeller when the impeller rotates in a second rotation direction of the impeller, and is tilted in the second rotation direction of the impeller when the impeller rotates in the first rotation direction of the impeller. Accordingly, regardless of the rotation direction of the impeller, the air volume of the impeller can be maintained substantially constant when the rotation speed is the same, and thus the motor can be efficiently cooled by the impeller.

In this case, the impeller preferably further includes a stopper to maintain a tilted posture of the movable blade. Accordingly, the air volume of the impeller can be more reliably maintained substantially constant, and thus the motor can be more efficiently cooled by the impeller.

According to the present disclosure, as described above, it is possible to reduce or prevent an increase in the number of components required to cool the motor and to reduce or prevent the complexity of the structure of the robot.

DETAILED DESCRIPTION

Embodiments embodying the present disclosure are hereinafter described on the basis of the drawings.

First Embodiment

The structure of a SCARA robot100according to a first embodiment of the present disclosure is described with reference toFIGS.1to5. The SCARA robot100is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIGS.1and2, the SCARA robot100is a robot including arms that move in a horizontal direction. The SCARA robot100includes a base1, a first motor2, a first speed reducer3, a second motor4, a second speed reducer5, a third motor6, a fourth motor7, a first arm8, a second arm9, and a working unit10. The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer3is an example of a “speed reducer” in the claims.

The base1is a base for fixing the SCARA robot100to an installation surface. The first motor2is a drive source that generates a driving force for driving the first arm8. The first motor2is arranged in an external space S1of the base1attached to the first speed reducer3. The first speed reducer3slows down rotation of the first motor2. The second motor4is a drive source that generates a driving force for driving the second arm9. The second speed reducer5slows down rotation of the second motor4. The third motor6is a drive source for driving a lifting and lowering device (not shown) that lifts and lowers the working unit10. The fourth motor7is a drive source for driving a rotary drive device (not shown) that rotates the working unit10.

The first arm8is relatively rotatably attached to the base1. The first speed reducer3slows down rotation of the first motor2and transmits the slowed down rotation to the first arm8such that the first arm8rotates about a rotation axis J1with respect to the base1. The second arm9is relatively rotatably attached to the first arm8. The second speed reducer5slows down rotation of the second motor4and transmits the slowed down rotation to the second arm9such that the second arm9rotates about a rotation axis J2with respect to the first arm8.

A first joint8ais provided at a portion connecting the first arm8to the base1. The first joint8ais configured by connecting a portion of the base1on the first arm8side and a portion of the first arm8on the base1side. Furthermore, a second joint9athat is a portion connecting the first arm8to the second arm9is provided. The second joint9ais configured by connecting a portion of the first arm8on the second arm9side and a portion of the second arm9on the first arm8side.

Thus, in the SCARA robot100, rotation of the first arm8, rotation of the second arm9, lifting and lowering by the lifting and lowering device (not shown), and rotation by the rotary drive device (not shown) are combined such that desired work is performed by the working unit10.

Joint Structure Connecting Base to First Arm

In the SCARA robot100according to the first embodiment, as shown inFIG.3, an impeller17described below is rotated as the first arm8rotates such that the first motor2is cooled. Such a joint structure (first joint8a) connecting the base1to the first arm8is described below in detail.

As shown inFIGS.3and4, the SCARA robot100includes the base1, the first motor2, the first speed reducer3, the first arm8, wiring11, a motor holder12, an oil seal13, a stay14, a clamp15, a grommet16, and the impeller17.

The first speed reducer3is an eccentrically oscillating speed reducer. In particular, the first speed reducer3is a rotate vector (RV) speed reducer. The first speed reducer3includes an input31, a speed reduction portion32, an output33, and a carrier34.

A shaft21of the first motor2is connected to the input31. Furthermore, the input31includes an input gear. The input31is rotated by the driving force of the first motor2.

The speed reduction portion32slows down and transmits the rotation from the input31. Specifically, the speed reduction portion32includes a spur gear32a, an eccentric rotator32b, and an external gear32c.

The spur gear32atransmits the driving force from the input31to the eccentric rotator32b. The spur gear32ameshes with the input gear. The spur gear32ais arranged on the base1side of the eccentric rotator32bin a direction in which a rotation axis J1of the input31extends.

The eccentric rotator32bincludes a plurality of (two or three) crankshafts132. The spur gear32aslows down rotation of the input31and transmits the slowed down rotation to the eccentric rotator32b. The external gear32cincludes a plurality of (two) RV gears. The external gear32cis swingably provided on the carrier34, swings with rotation of the crankshaft132, slows down rotation of the crankshaft132, and transmits the slowed down rotation to the output33. The output33is a case. The output33rotates by the driving force from the speed reduction portion32. That is, the output33rotates about the rotation axis J1with swinging of the external gear32c. Thus, the first arm8is rotated by an output from the output33of the first speed reducer3.

As shown inFIG.3, the carrier34is arranged inside the output33. The carrier34is attached to the base1so as not to rotate as the first arm8rotates. Furthermore, the first motor2is attached to the carrier34.

Specifically, the carrier34includes a first carrier34aand a second carrier34b. The first carrier34ais provided on the opposite side to the base1side in a direction in which a rotation axis J1with respect to the eccentric rotator32bextends. One first motor2is attached to the first carrier34a. The first motor2is fixed to the first carrier34aby being fastened via the motor holder12by a fastening member B1. The second carrier34bis connected to the first carrier34aby a fastening member B2and a pin (not shown), for example. The second carrier34bis provided on the base1side in the direction in which the rotation axis J1with respect to the eccentric rotator32bextends. The second carrier34bis attached to the base1. That is, the second carrier34bis fixed to the base1by a fastening member B3.

Thus, the first motor2does not rotate as the first arm8rotates.

The output33is connected to the first arm8such that the first arm8rotates together with the output33. The first arm8is attached to the output33by a fastening member B4. Thus, the first arm8is attached to the base1via the first speed reducer3. The wiring11is motor wiring connected to the first motor2.

The motor holder12is a frame made of metal such as aluminum. The motor holder12is arranged on the side of the first carrier34aopposite to the base1. The motor holder12is attached to the carrier34while holding the first motor2. That is, the motor holder12is fastened to the first carrier34aby the fastening member B1while holding the first motor2. The first motor2is fastened to the motor holder12by a fastening member B5. The first motor2is fixed to the carrier34via the motor holder12while being arranged in the external space S1of the base1. The first motor2is arranged on the side of the motor holder12opposite to the base1. Thus, the motor holder12holds the first motor2in an air passage W of the impeller17.

The oil seal13is arranged between the motor holder12and the first arm8. The oil seal13is arranged between the motor holder12and the first arm8on the opposite side to the base1side. The stay14is fixed to the base1by a fastening member B6. The stay14is provided to support the wiring11. A through-hole14ais formed in the stay14to allow an internal space S2of the base1to communicate with the external space S1of the base1. The clamp15is a member for attaching the wiring11to the stay14. The grommet16is attached to the stay14in order to pass the wiring11through the stay14.

The impeller17is a centrifugal impeller. A centrifugal impeller is an impeller that generates wind by sucking air from one side in the direction in which the rotation axis J1extends and sending air radially outward, both when the impeller17rotates clockwise and when the impeller17rotates counterclockwise.

The impeller17rotates together with the first arm8. The impeller17is attached to the first arm8and rotates together with the first arm8. The impeller17rotates about the same axis as a rotation axis J1of the output33of the first speed reducer3.

The impeller17rotates together with the first arm8and generates wind to cool the first motor2. That is, the impeller17cools the first motor2by using relative movement of the first arm8with respect to the first motor2. Furthermore, the impeller17and the first speed reducer3are connected to each other via the first arm8in a heat conductive manner. Thus, heat transferred from the first speed reducer3is released from the impeller17. Consequently, the first speed reducer3is cooled.

As shown inFIGS.4and5, the impeller17sends out wind by causing the wind to follow the same air passage W both when the first arm8rotates clockwise and when the first arm8rotates counterclockwise. The air passage W is a path from one side in the direction in which the rotation axis J1extends toward the impeller17and in a direction perpendicular to the rotation axis J1.

The impeller17surrounds the first motor2. Thus, the first motor2is arranged in the air passage W, and thus the wind hits the first motor2to cool the first motor2.

The impeller17is formed into an annular shape with a space in the center in the radial direction. The impeller17includes a first mount17a, a second mount17b, and a plurality of (six) blades17c. The first mount17ais attached to a portion of each of the plurality of blades17con the side opposite to the base1. The second mount17bis attached to a portion of each of the plurality of blades17con the base1side. Each of the plurality of blades17cis an arcuate thin plate.

Advantageous Effects of First Embodiment

According to the first embodiment, the following advantageous effects are achieved.

According to the first embodiment, as described above, the impeller17is operable to rotate together with the first arm8and generate wind to cool the first motor2. Accordingly, the wiring11or the like is not required to drive the impeller17, and thus an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot100can be reduced or prevented.

According to the first embodiment, as described above, the impeller17is attached to the first arm8to rotate together with the first arm8. Accordingly, the impeller17can be rotated simply by attaching the impeller17to the first arm8, and thus a structure to rotate the impeller17can be easily achieved.

According to the first embodiment, as described above, the impeller17includes the centrifugal impeller operable to rotate together with the first arm8. Accordingly, wind can be generated by rotating the centrifugal impeller together with the first arm8, and thus a structure to generate wind so as to cool the first motor2can be easily achieved.

According to the first embodiment, as described above, the centrifugal impeller surrounds the first motor2. Accordingly, wind can be evenly applied to the first motor2, and thus the first motor2can be effectively cooled.

According to the first embodiment, as described above, the impeller17is operable to rotate about the same axis as the rotation axis J1of the output33of the first speed reducer3. Accordingly, the impeller17can be prevented from rotating eccentrically, and thus rotation of the impeller17can be stabilized.

According to the first embodiment, as described above, the impeller17is attached to the first arm8. The first arm8is attached to the output33of the first speed reducer3. The impeller17and the first speed reducer3are connected to each other via the first arm8in a heat conductive manner. Accordingly, not only the first motor2but also the first speed reducer3can be cooled by the impeller17, and thus an increase in temperature at a joint portion of the SCARA robot100can be effectively reduced or prevented.

According to the first embodiment, as described above, the SCARA robot100includes the motor holder12to hold the first motor2in the air passage W of the impeller17. Accordingly, wind can be stably applied to the first motor2, and thus the first motor2can be effectively cooled.

According to the first embodiment, as described above, the SCARA robot100includes the first joint8athat is a portion connecting the first arm8to the base1, and the second joint9athat is a portion connecting the first arm8to the second arm9. The first motor2is arranged in the external space S1of the base1attached to the first speed reducer3. Accordingly, the first motor2can be cooled not only by the wind from the impeller17but also by being exposed to outside air, and thus the first motor2can be more effectively cooled.

Second Embodiment

The structure of a SCARA robot200according to according to a second embodiment is described with reference toFIG.6. In the second embodiment, a first speed reducer203includes a hollow transmission shaft231a, unlike the first embodiment. In the second embodiment, detailed description of the same or similar structures as those of the first embodiment is omitted.

The structure of the SCARA robot200according to the second embodiment of the present disclosure is described with reference toFIG.6. The SCARA robot200is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.6, the SCARA robot200is a robot including arms that move in a horizontal direction. The SCARA robot200includes a base201, a first motor2, the first speed reducer203, a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm8, a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer203is an example of a “speed reducer” in the claims.

The base201includes a base-side filter portion201a. The base-side filter portion201ais a slit. The base-side filter portion201aallows an external space S1of the base201and an internal space S2of the base201to communicate with each other. The base-side filter portion201aremoves foreign matter from air while allowing the air to flow from the external space S1of the base201to the internal space S2of the base201. The base-side filter portion201amay be a filter.

A first joint208ais provided at a portion connecting the first arm8to the base201. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot200according to the second embodiment, as shown inFIG.6, an impeller17described below is rotated as the first arm8rotates such that the first motor2is cooled. Such a joint structure (first joint208a) connecting the base201to the first arm8is described below in detail.

As shown inFIG.6, the SCARA robot200includes the base201, the first motor2, the first speed reducer203, the first arm8, wiring11, a motor holder12, an oil seal13, a first stay214, a first clamp215, a shaft cover216, the impeller17, a second stay218, and a second clamp219.

The first speed reducer203is an eccentrically oscillating speed reducer. In particular, the first speed reducer203is an RV speed reducer. The first speed reducer203includes an input231, a speed reduction portion32, an output33, and a carrier34.

The input231is rotated by a driving force of the first motor2. The input231includes the hollow transmission shaft231a. The transmission shaft231aincludes a through-hole231bthat penetrates in a direction in which a rotation axis J1of the input231extends. The transmission shaft231atransmits the driving force from the first motor2to the speed reduction portion32.

The first stay214is fixed to the base201by a fastening member B6. The first stay214is provided to support the wiring11. The first clamp215is a member for attaching the wiring11to the first stay214.

The impeller17is a centrifugal impeller. The impeller17cools the first speed reducer203by rotating together with the first arm8, generating wind, and causing the generated wind to flow into the through-hole231bof the transmission shaft231a. An air passage W1is a path from the base1side in the direction in which the rotation axis J1extends toward the impeller17and in a direction perpendicular to the rotation axis J1. Furthermore, an air passage W2is a path from the opposite side to the base1side in the direction in which the rotation axis J1extends through the through-hole231bof the transmission shaft231atoward the impeller17and in the direction perpendicular to the rotation axis J1.

Other Structures

The shaft cover216covers the first motor2side of the through-hole231bof the transmission shaft231ain the direction in which the rotation axis J1of the input231extends. The shaft cover216includes a speed reducer-side filter portion216athat removes foreign matter from air while allowing the air to flow from the internal space S2of the base201to the external space S1of the base201through the through-hole231busing the wind of the impeller17. The speed reducer-side filter portion216ais a slit. The speed reducer-side filter portion216amay have a structure in which a grommet is attached to a filter.

The second stay218is fixed to the base201by a fastening member B7. The second stay218is provided to support the wiring11. The second clamp219is a member for attaching the wiring11to the second stay218. The remaining structures of the second embodiment are similar to those of the first embodiment.

Advantageous Effects of Second Embodiment

According to the second embodiment, similarly to the first embodiment, the impeller17is operable to rotate together with the first arm8and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot200can be reduced or prevented.

According to the second embodiment, as described above, the input31includes the hollow transmission shaft231aincluding the through-hole231bthat penetrates in the direction in which the rotation axis J1of the input231extends and operable to transmit the driving force from the first motor2to the speed reduction portion32. The centrifugal impeller is operable to cool the first speed reducer3by rotating together with the first arm8, generating wind, and causing the generated wind to flow into the through-hole231bof the transmission shaft231a. Accordingly, not only the first motor2but also the first speed reducer3can be cooled, and thus an increase in temperature at a joint portion of the SCARA robot200can be effectively reduced or prevented. The remaining advantageous effects of the second embodiment are similar to the advantageous effects of the first embodiment.

Third Embodiment

The structure of a SCARA robot300according to a third embodiment is described with reference toFIG.7. In the third embodiment, an impeller316is an axial flow impeller, unlike the first embodiment. In the third embodiment, detailed description of the same or similar structures as those of the first embodiment is omitted.

The structure of the SCARA robot300according to the third embodiment of the present disclosure is described with reference toFIG.7. The SCARA robot300is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.7, the SCARA robot300is a robot including arms that move in a horizontal direction. The SCARA robot300includes a base301, a first motor2, a first speed reducer303, a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm8, a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer303is an example of a “speed reducer” in the claims.

The base301includes a base-side filter portion301a. The base-side filter portion301ais a slit. The base-side filter portion301aallows an external space S1of the base301and an internal space S2of the base301to communicate with each other. The base-side filter portion301aremoves foreign matter from air while allowing the air to flow from the external space S1of the base301to the internal space S2of the base301. The base-side filter portion301amay be a filter.

A first joint308ais provided at a portion connecting the first arm8to the base301. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot300according to the third embodiment, as shown inFIG.7, the impeller316described below is rotated as the first speed reducer303rotates such that the first motor2and the first speed reducer303are cooled. Such a joint structure (first joint308a) connecting the base301to the first arm8is described below in detail.

As shown inFIG.7, the SCARA robot300includes the base301, the first motor2, the first speed reducer303, the first arm8, wiring11, a motor holder12, an oil seal13, a stay314, a clamp15, the impeller316, and an insertion tube317.

The first speed reducer303is an eccentrically oscillating speed reducer. In particular, the first speed reducer303is an RV speed reducer. The first speed reducer303includes an input331, a speed reduction portion32, an output33, and a carrier34.

The input331is rotated by a driving force of the first motor2. The input331includes a hollow transmission shaft331a. The transmission shaft331aincludes a through-hole331bthat penetrates in a direction in which a rotation axis J1of the input331extends. The transmission shaft331atransmits the driving force from the first motor2to the speed reduction portion32.

The stay314is fixed to the motor holder12by a fastening member B6. The stay314is provided to support the wiring11. The stay314includes a speed reducer-side filter portion314athat removes foreign matter from air while allowing the air to flow from the external space S1of the base301to the internal space S2of the base301through the through-hole331busing wind of the impeller316. The speed reducer-side filter portion314ais a slit. The speed reducer-side filter portion314amay be a filter.

The impeller316is an axial flow impeller. The axial flow impeller refers to an impeller that generates wind by sucking air from one side in the direction in which the rotation axis J1extends and sending out the air toward the other side in the direction in which the rotation axis J1extends when the impeller rotates clockwise or counterclockwise.

The impeller316rotates together with the first speed reducer303. The impeller316is attached to the input331of the first speed reducer303and rotates together with the first speed reducer303. The impeller316rotates about the same axis as a rotation axis J1of the output33of the first speed reducer303.

The impeller316rotates together with the first speed reducer303and generates wind to cool the first motor2and the first speed reducer303. That is, the impeller316cools the first motor2by using relative movement of the first speed reducer303with respect to the first motor2. Furthermore, the impeller316and the first speed reducer303are directly connected to each other in a heat conductive manner. Thus, heat transferred from the first speed reducer303is released from the impeller316.

As shown inFIG.7, the impeller316sends out wind by causing the wind to follow an air passage W when rotating clockwise or counterclockwise. The air passage W has a path from the base301side to the first motor2side in the direction in which the rotation axis J1extends, and a path from the first motor2side to the base301side in the direction in which the rotation axis J1extends. That is, the air passage W has two paths because the direction of the wind changes depending on whether the impeller316rotates clockwise or counterclockwise.

The impeller316is arranged in the through-hole331bof the transmission shaft331a. Thus, the wind passes through the first speed reducer303, and thus the first speed reducer303is cooled. Furthermore, the wind emitted from the impeller316or drawn into the impeller316hits the first motor2to cool the first motor2.

Insertion Tube

The wiring11is inserted into the insertion tube317. The insertion tube317includes a through-hole317ainto which the wiring11is inserted. The insertion tube317is arranged inside the impeller316. The remaining structures of the third embodiment are similar to those of the first embodiment.

Advantageous Effects of Third Embodiment

According to the third embodiment, similarly to the first embodiment, the impeller316is operable to rotate together with the first speed reducer303and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot300can be reduced or prevented.

According to the third embodiment, as described above, the impeller316is attached to the input331of the first speed reducer303to rotate together with the input331. Accordingly, the impeller316can be rotated simply by attaching it to the input331of the first speed reducer303, and thus a structure to rotate the impeller316can be easily achieved.

According to the third embodiment, as described above, the base301is attached to the first speed reducer303. The input331includes the hollow transmission shaft331aincluding the through-hole331bthat penetrates in the direction in which the rotation axis J1of the input331extends and operable to transmit the driving force from the first motor2to the speed reduction portion32. The axial flow impeller is arranged in the through-hole331bof the transmission shaft331a. Accordingly, the first speed reducer303can be cooled from the inside by the wind generated by the axial flow impeller, and thus the first speed reducer303can be effectively cooled. Furthermore, the axial flow impeller is arranged in the through-hole331bof the transmission shaft331asuch that the size of the axial flow impeller is sized to match the size of the through-hole331b, and thus the impeller316can be downsized as compared with a case in which a centrifugal impeller arranged outside the through-hole331bof the transmission shaft331ais used.

According to the third embodiment, as described above, the SCARA robot300includes the wiring11connected to the first motor2. The insertion tube317into which the wiring11is inserted is arranged inside the axial flow impeller. Accordingly, unlike a case in which the wiring11is placed outside the first speed reducer303, the wiring11can be contained within the first speed reducer303, and thus exposure of the wiring11can be reduced.

According to the third embodiment, as described above, the base301includes the base-side filter portion301ato allow the external space S1of the base301and the internal space S2of the base301to communicate with each other, and remove foreign matter from air while allowing the air to flow from the external space S1of the base301to the internal space S2of the base301. Accordingly, while entry of foreign matter into the base301is reduced or prevented, wind can be sent from the internal space S2of the base301to the external space S1by the axial flow impeller. Thus, entry of foreign matter into the internal space S2of the base301can be reduced or prevented, and the first speed reducer303and the first motor2can be cooled.

According to the third embodiment, as described above, the stay314includes the speed reducer-side filter portion314ato remove foreign matter from air while allowing the air to flow from the external space S1of the base301to the internal space S2of the base301through the through-hole331busing the wind of the impeller316. Accordingly, while entry of foreign matter into the base301is reduced or prevented, wind can be sent from the external space S1of the base301to the internal space S2by the axial flow impeller. Thus, entry of foreign matter into the internal space S2of the base301can be reduced or prevented, and the first speed reducer303and the first motor2can be cooled. The remaining advantageous effects of the third embodiment are similar to the advantageous effects of the first embodiment.

Fourth Embodiment

The structure of a SCARA robot400according to a fourth embodiment is described with reference toFIG.8. In the fourth embodiment, the SCARA robot400does not include an insertion tube, unlike the third embodiment. In the fourth embodiment, detailed description of the same or similar structures as those of the third embodiment is omitted.

The structure of the SCARA robot400according to the fourth embodiment of the present disclosure is described with reference toFIG.8. The SCARA robot400is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.8, the SCARA robot400is a robot including arms that move in a horizontal direction. The SCARA robot400includes a base301, a first motor2, a first speed reducer303, a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm8, a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer303is an example of a “speed reducer” in the claims.

A first joint308ais provided at a portion connecting the first arm8to the base301. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot400according to the fourth embodiment, as shown inFIG.8, an impeller416described below is rotated as the first speed reducer303rotates such that the first motor2is cooled. Such a joint structure (first joint308a) connecting the base301to the first arm8is described below in detail.

As shown inFIG.8, the SCARA robot400includes the base301, the first motor2, the first speed reducer303, the first arm8, wiring11, a motor holder12, an oil seal13, a stay14, a clamp15, the impeller416, and a shaft cover417.

The impeller416is an axial flow impeller. The impeller416rotates together with the first speed reducer303. The impeller416is attached to an input331of the first speed reducer303and rotates together with the first speed reducer303. The impeller416rotates about the same axis as a rotation axis J1of an output33of the first speed reducer303.

Shaft Cover

The shaft cover417covers the first motor2side of a through-hole331bof a transmission shaft331ain a direction in which a rotation axis J1of the input331extends. The shaft cover417includes a speed reducer-side filter portion417a. The speed reducer-side filter portion417aremoves foreign matter from air while allowing the air to flow from an external space S1of the base301to an internal space S2of the base301through the through-hole331busing wind of the impeller416. The speed reducer-side filter portion417ais a slit. The speed reducer-side filter portion417amay be a filter. The remaining structures of the fourth embodiment are similar to those of the first embodiment.

Advantageous Effects of Fourth Embodiment

According to the fourth embodiment, similarly to the third embodiment, the impeller416is operable to rotate together with the first speed reducer303and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot400can be reduced or prevented.

According to the fourth embodiment, as described above, the SCARA robot400includes the shaft cover417to cover the first motor2side of the through-hole331bof the transmission shaft331ain the direction in which the rotation axis J1of the input331extends. The shaft cover417includes the speed reducer-side filter portion417ato remove foreign matter from air while allowing the air to flow from the external space S1of the base301to the internal space S2of the base301through the through-hole331busing the wind of the axial flow impeller. Accordingly, while entry of foreign matter into the transmission shaft331ais reduced or prevented, wind can be sent to the external space S1of the base301by the axial flow impeller. Thus, entry of foreign matter into the internal space S2of the base301can be reduced or prevented, and the first speed reducer303and the first motor2can be cooled. The remaining advantageous effects of the fourth embodiment are similar to the advantageous effects of the third embodiment.

Fifth Embodiment

The structure of a SCARA robot500according to a fifth embodiment is described with reference toFIG.9. In the fifth embodiment, the SCARA robot500includes a motor cover517, unlike the fourth embodiment. In the fifth embodiment, detailed description of the same or similar structures as those of the fourth embodiment is omitted.

The structure of the SCARA robot500according to the fifth embodiment of the present disclosure is described with reference toFIG.9. The SCARA robot500is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.9, the SCARA robot500is a robot including arms that move in a horizontal direction. The SCARA robot500includes a base301, a first motor2, a first speed reducer303, a second motor4, a second speed reducer5, a third motor6, a fourth motor7, a first arm8, a second arm9, and a working unit10. The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer303is an example of a “speed reducer” in the claims.

A first joint308ais provided at a portion connecting the first arm8to the base301. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot500according to the fifth embodiment, as shown inFIG.9, an impeller416described below is rotated as the first speed reducer303rotates such that the first motor2is cooled. Such a joint structure (first joint308a) connecting the base301to the first arm8is described below in detail.

As shown inFIG.9, the SCARA robot500includes the base301, the first motor2, the first speed reducer303, the first arm8, wiring11, a motor holder12, an oil seal13, a stay14, a clamp15, the impeller416, the motor cover517, and a thermal conductor518.

The impeller416is an axial flow impeller. The impeller416rotates together with the first speed reducer303. The impeller416is attached to an input331of the first speed reducer303and rotates together with the first speed reducer303. The impeller416rotates about the same axis as a rotation axis J1of an output33of the first speed reducer303.

Motor Cover

The motor cover517is a housing that covers the first motor2. The motor cover517includes a motor-side filter portion517a. The motor-side filter portion517aremoves foreign matter from air while allowing the air to flow from an external space S1of the base301to an internal space S2of the base301. The motor-side filter portion517ais a slit. The motor-side filter portion517amay be a filter.

Thermal Conductor

The thermal conductor518conducts heat from the first motor2to the motor cover517. The first motor2and the motor cover517are connected to each other via the thermal conductor518. The remaining structures of the fifth embodiment are similar to those of the fourth embodiment.

Advantageous Effects of Fifth Embodiment

According to the fifth embodiment, similarly to the third embodiment, the impeller416is operable to rotate together with the first speed reducer303and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot500can be reduced or prevented.

According to the fifth embodiment, as described above, the SCARA robot500includes the motor cover517to cover the first motor2and including the motor-side filter portion517ato remove foreign matter from air while allowing the air to flow from the external space S1of the base301to the internal space S2of the base301. Accordingly, adhesion of foreign matter to the first motor2can be reduced or prevented, and wind can be applied to the first motor2. Thus, the first motor2can be effectively cooled.

According to the fifth embodiment, as described above, the first motor2and the motor cover517are in contact with each other via the thermal conductor518. Accordingly, the heat of the first motor2can be released by the motor cover517, and thus the first motor2can be effectively cooled. The remaining advantageous effects of the fifth embodiment are similar to the advantageous effects of the fourth embodiment.

Sixth Embodiment

The structure of a SCARA robot600according to a sixth embodiment is described with reference toFIG.10. In the sixth embodiment, the SCARA robot600includes a motor cover617, unlike the third embodiment. In the sixth embodiment, detailed description of the same or similar structures as those of the third embodiment is omitted.

The structure of the SCARA robot600according to the sixth embodiment of the present disclosure is described with reference toFIG.10. The SCARA robot600is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.10, the SCARA robot600is a robot including arms that move in a horizontal direction. The SCARA robot600includes a base301, a first motor2, a first speed reducer303, a second motor4, a second speed reducer5, a third motor6, a fourth motor7, a first arm8, a second arm9, and a working unit10. The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer303is an example of a “speed reducer” in the claims.

A first joint308ais provided at a portion connecting the first arm8to the base301. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot600according to the sixth embodiment, as shown inFIG.10, an impeller316described below is rotated as the first speed reducer303rotates such that the first motor2and the first speed reducer303are cooled. Such a joint structure (first joint308a) connecting the base301to the first arm8is described below in detail.

As shown inFIG.10, the SCARA robot600includes the base301, the first motor2, the first speed reducer303, the first arm8, wiring11, a motor holder12, an oil seal13, a stay314, a clamp15, the impeller316, an insertion tube317, the motor cover617, and a thermal conductor618.

The impeller316is an axial flow impeller. The impeller316rotates together with the first speed reducer303. The impeller316is attached to an input331of the first speed reducer303and rotates together with the first speed reducer303. The impeller316rotates about the same axis as a rotation axis J1of an output33of the first speed reducer303.

Motor Cover

The motor cover617is a housing that covers the first motor2. The motor cover617includes a motor-side filter portion617a. The motor-side filter portion617aremoves foreign matter from air while allowing the air to flow from an external space S1of the base301to an internal space S2of the base301. The motor-side filter portion617ais a slit. The motor-side filter portion617amay be a filter.

Thermal Conductor

The thermal conductor618conducts heat from the first motor2to the motor cover617. The first motor2and the motor cover617are connected to each other via the thermal conductor618. The remaining structures of the sixth embodiment are similar to those of the third embodiment.

Advantageous Effects of Sixth Embodiment

According to the sixth embodiment, similarly to the third embodiment, the impeller316is operable to rotate together with the first speed reducer303and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot600can be reduced or prevented. The remaining advantageous effects of the sixth embodiment are similar to the advantageous effects of the third embodiment.

Seventh Embodiment

The structure of a SCARA robot700according to a seventh embodiment is described with reference toFIG.11. In the seventh embodiment, the SCARA robot700includes a motor cover720, unlike the second embodiment. In the seventh embodiment, detailed description of the same or similar structures as those of the second embodiment is omitted.

The structure of the SCARA robot700according to the seventh embodiment of the present disclosure is described with reference toFIG.11. The SCARA robot700is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.11, the SCARA robot700is a robot including arms that move in a horizontal direction. The SCARA robot700includes a base201, a first motor2, a first speed reducer203, a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm8, a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer203is an example of a “speed reducer” in the claims.

A first joint208ais provided at a portion connecting the first arm8to the base201. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot700according to the seventh embodiment, as shown inFIG.11, an impeller17described below is rotated as the first arm8rotates such that the first motor2is cooled. Such a joint structure (first joint208a) connecting the base201to the first arm8is described below in detail.

As shown inFIG.11, the SCARA robot700includes the base201, the first motor2, the first speed reducer203, the first arm8, wiring11, a motor holder12, an oil seal13, a first stay214, a first clamp215, a shaft cover216, the impeller17, a second stay218, a second clamp219, and the motor cover720.

The impeller17is a centrifugal impeller. The impeller17cools the first speed reducer203by rotating together with the first arm8, generating wind, and causing the generated wind to flow into a through-hole231bof a transmission shaft231a.

Motor Cover

The motor cover720is a housing that covers the first motor2. The motor cover720is attached to the side of the impeller17opposite to the base201side. The motor cover720includes a motor-side filter portion720a. The motor-side filter portion720aremoves foreign matter from air while allowing the air to flow from an internal space S2of the base201to an external space S1of the base201. The motor-side filter portion720ais a slit. The motor-side filter portion720amay be a filter. The remaining structures of the seventh embodiment are similar to those of the second embodiment.

Advantageous Effects of Seventh Embodiment

According to the seventh embodiment, similarly to the second embodiment, the impeller17is operable to rotate together with the first arm8and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot700can be reduced or prevented. The remaining advantageous effects of the seventh embodiment are similar to the advantageous effects of the second embodiment.

Eighth Embodiment

The structure of a SCARA robot800according to an eighth embodiment is described with reference toFIG.12. In the eighth embodiment, the SCARA robot800includes a motor cover820, unlike the second embodiment. In the eighth embodiment, detailed description of the same or similar structures as those of the second embodiment is omitted.

The structure of the SCARA robot800according to the eighth embodiment of the present disclosure is described with reference toFIG.12. The SCARA robot800is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.12, the SCARA robot800is a robot including arms that move in a horizontal direction. The SCARA robot800includes a base201, a first motor2, a first speed reducer203, a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm8, a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer203is an example of a “speed reducer” in the claims.

A first joint208ais provided at a portion connecting the first arm8to the base201. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot800according to the eighth embodiment, as shown inFIG.12, an impeller17described below is rotated as the first arm8rotates such that the first motor2is cooled. Such a joint structure (first joint208a) connecting the base201to the first arm8is described below in detail.

As shown inFIG.12, the SCARA robot800includes the base201, the first motor2, the first speed reducer203, the first arm8, wiring11, a motor holder12, an oil seal13, a first stay214, a first clamp215, a shaft cover216, the impeller17, a second stay218, a second clamp219, and the motor cover820.

The impeller17is a centrifugal impeller. The impeller17cools the first speed reducer203by rotating together with the first arm8, generating wind, and causing the generated wind to flow into a through-hole231bof a transmission shaft231a.

Motor Cover

The motor cover820is a housing that covers the first motor2and the impeller17. The motor cover820is attached to the side of the first arm8opposite to the base201side. The motor cover820includes a motor-side filter portion820a. The motor-side filter portion820aremoves foreign matter from air while allowing the air to flow from an external space S1of the base201to an internal space S2of the base201. The motor-side filter portion820ais a slit. The motor-side filter portion820amay be a filter. The remaining structures of the eighth embodiment are similar to those of the second embodiment.

Advantageous Effects of Eighth Embodiment

According to the eighth embodiment, similarly to the second embodiment, the impeller17is operable to rotate together with the first arm8and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot800can be reduced or prevented. The remaining advantageous effects of the eighth embodiment are similar to the advantageous effects of the second embodiment.

Ninth Embodiment

The structure of a SCARA robot900according to a ninth embodiment is described with reference toFIG.13. In the ninth embodiment, the SCARA robot900does not include an insertion tube, unlike the fourth embodiment. In the ninth embodiment, detailed description of the same or similar structures as those of the fourth embodiment is omitted.

The structure of the SCARA robot900according to the ninth embodiment of the present disclosure is described with reference toFIG.13. The SCARA robot900is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.13, the SCARA robot900is a robot including arms that move in a horizontal direction. The SCARA robot900includes a base301, a first motor2, a first speed reducer903, a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm908, a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer903is an example of a “speed reducer” in the claims.

A first joint308ais provided at a portion connecting the first arm8to the base301. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot900according to the ninth embodiment, an impeller416described below is rotated as the first speed reducer903rotates such that the first motor2is cooled. Such a joint structure (first joint308a) connecting the base301to the first arm908is described below in detail.

The first motor2is attached to the base301. The first motor2is fastened to the base301by a fastening member B1. Thus, the first motor2is attached to the base301while being arranged in an internal space S2of the base301. Consequently, the first motor2does not rotate as the first arm908rotates.

The SCARA robot900includes the base301, the first motor2, the first speed reducer903, the first arm908, and the impeller416.

The first speed reducer903is an eccentrically oscillating speed reducer. In particular, the first speed reducer903is an RV speed reducer. The first speed reducer903includes an input331, a speed reduction portion32, an outer case933, and a carrier934. The carrier934is an example of an “output” in the claims.

The outer case933is attached to the base301by a fastening member B2. Thus, the outer case933does not rotate due to a driving force from the speed reduction portion32.

The carrier934is arranged inside the outer case933. The carrier934rotates by the driving force from the speed reduction portion32to rotate the first arm908. The carrier934is attached to the first arm908.

Specifically, the carrier934includes a first carrier portion934aand a second carrier portion934b. The first carrier portion934ais provided on the base301side in a direction in which a rotation axis J1of the input331extends. The second carrier portion934bis connected to the first carrier portion934aby a fastening member B3and a pin (not shown), for example. The second carrier portion934bis provided on the opposite side to the base301side in the direction in which the rotation axis J1of the input331extends. The second carrier portion934bis attached to the first arm908. That is, the second carrier portion934bis fixed to the first arm908by a fastening member B4.

The first arm908rotates together with the carrier934when the carrier934is connected thereto. The first arm908is attached to the carrier934by the fastening member B4. The first arm908includes an arm-side filter portion981. The arm-side filter portion981removes foreign matter from air while allowing the air to flow from an external space S1of the base301to the internal space S2of the base301. The arm-side filter portion981is a slit. The arm-side filter portion981may be a filter.

The impeller416is an axial flow impeller. The impeller416rotates together with the first speed reducer903. Thus, the impeller416sends wind to the first motor2arranged in the internal space S2of the base301. The remaining structures of the ninth embodiment are similar to those of the fourth embodiment.

Advantageous Effects of Ninth Embodiment

According to the ninth embodiment, similarly to the fourth embodiment, the impeller416is operable to rotate together with the first speed reducer903and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot900can be reduced or prevented.

According to the ninth embodiment, as described above, the SCARA robot900includes the first joint308athat is a portion connecting the first arm8to the base301, and the second joint9athat is a portion connecting the first arm8to the second arm9. The first motor2is attached to the base301while being arranged in the internal space S2of the base301. The axial flow impeller is operable to send wind to the first motor2arranged in the internal space S2of the base301. Accordingly, even when the first motor2is arranged in the internal space S2of the base301, the axial flow impeller can apply wind to the first motor2, and thus the first motor2can be effectively cooled. The remaining advantageous effects of the ninth embodiment are similar to the advantageous effects of the fourth embodiment.

Tenth Embodiment

The structure of a SCARA robot1000according to a tenth embodiment is described with reference toFIG.14. In the tenth embodiment, the SCARA robot1000includes a harmonic speed reducer as a speed reducer, unlike the ninth embodiment. In the tenth embodiment, detailed description of the same or similar structures as those of the ninth embodiment is omitted.

The structure of the SCARA robot1000according to the tenth embodiment of the present disclosure is described with reference toFIG.14. The SCARA robot1000is an example of a “robot” in the claims.

Structure of SCARA Robot

As shown inFIG.14, the SCARA robot1000is a robot including arms that move in a horizontal direction. The SCARA robot1000includes a base301, a first motor2, a first speed reducer1003, a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm908, a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer1003is an example of a “speed reducer” in the claims.

A first joint308ais provided at a portion connecting the first arm8to the base301. Furthermore, a second joint9a(seeFIG.1) that is a portion connecting the first arm8to the second arm9is provided.

Joint Structure Connecting Base to First Arm

In the SCARA robot1000according to the tenth embodiment, an impeller416described below is rotated as the first speed reducer1003rotates such that the first motor2is cooled. Such a joint structure (first joint308a) connecting the base301to the first arm908is described below in detail.

The first speed reducer1003is a hollow speed reducer. In particular, the first speed reducer1003is a harmonic speed reducer. The first speed reducer1003includes an input331, a fixed portion1032below a flex spline, and an output1033above a circular spline.

The input331is a wave generator. The fixed portion1032is attached to the base301by a fastening member B1. The output1033is attached to the first arm908by a fastening member B2. The output1033slows down and outputs rotation of the input331. Thus, the output1033also functions as a speed reduction portion. The output1033is an example of a “speed reduction portion” in the claims. The remaining structures of the tenth embodiment are similar to those of the ninth embodiment.

Advantageous Effects of Tenth Embodiment

According to the tenth embodiment, similarly to the ninth embodiment, the impeller416is operable to rotate together with the first speed reducer1003and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot1000can be reduced or prevented. The remaining advantageous effects of the tenth embodiment are similar to the advantageous effects of the ninth embodiment.

Eleventh Embodiment

The structure of a SCARA robot1100according to an eleventh embodiment is described with reference toFIGS.15to19. In the eleventh embodiment, an impeller1117includes movable blades1117c, unlike the first embodiment. In the eleventh embodiment, detailed description of the same or similar structures as those of the first embodiment is omitted.

The structure of the SCARA robot1100according to the eleventh embodiment of the present disclosure is described with reference toFIGS.15to19. The SCARA robot1100is an example of a “robot” in the claims.

Structure of SCARA Robot

The SCARA robot1100is a robot including arms that move in a horizontal direction. The SCARA robot1100includes a base1(seeFIG.1), a first motor2, a first speed reducer3(seeFIG.1), a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm8(seeFIG.1), a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer3is an example of a “speed reducer” in the claims.

Joint Structure Connecting Base to First Arm

In the SCARA robot1100according to the eleventh embodiment, as shown inFIG.15, the impeller1117described below is rotated as the first arm8rotates such that the first motor2is cooled. Such a joint structure connecting the base1to the first arm8is described below in detail.

The SCARA robot1100includes the base1(seeFIG.3), the first motor2(seeFIG.3), the first speed reducer3(seeFIG.3), the first arm8(seeFIG.3), wiring11(seeFIG.3), a motor holder12(seeFIG.3), an oil seal13(seeFIG.3), a stay14(seeFIG.3), a clamp15(seeFIG.3), a grommet16(seeFIG.3), and the impeller1117.

The impeller1117is a centrifugal impeller. The impeller1117includes a first mount17a, a second mount17b, a plurality of (six) movable blades1117c, a plurality of (six) stoppers1117d, and a plurality of stoppers1117e.

The first mount17ais attached to a portion of each of a plurality of blades17con the side opposite to the base1. The second mount17bis attached to a portion of each of the plurality of blades17con the base1side.

As shown inFIGS.16and17, each of the plurality of movable blades1117crotates about a rotation shaft1171described below. When the impeller1117rotates in a first rotation direction of the impeller1117, each of the plurality of movable blades1117cis tilted in a second rotation direction due to an inertial force accompanying the rotation of the impeller1117and the fluid force of wind flowing between the plurality of movable blades1117c. When the impeller1117rotates in the second rotation direction of the impeller1117, each of the plurality of movable blades1117cis tilted in the first rotation direction due to an inertial force accompanying the rotation of the impeller1117and the fluid force of wind flowing between the plurality of movable blades1117c. Each of the plurality of movable blades1117chas a thin plate shape.

The stoppers1117dmaintain the tilted postures of the corresponding movable blades1117c. Specifically, each of the stoppers1117dincludes the rotation shaft1171, a wedge1172, a tension spring1173, and a guide shaft1174.

As shown inFIGS.18and19, the rotation shaft1171includes a notch1171a. The notch1171ais formed to match the shape of the wedge1172such that the wedge1172can be inserted therein. The wedge1172restricts rotation of the rotation shaft1171by being inserted into the notch1171a. The wedge1172is a relatively heavy member, and moves outward in the radial direction of the impeller1117due to a centrifugal force accompanying rotation of the impeller1117. The tension spring1173urges the wedge1172inward in the radial direction of the impeller1117. The guide shaft1174guides movement of the wedge1172outward and inward in the radial direction of the impeller1117.

As shown inFIGS.16and17, the stoppers1117erestrict rotation of the corresponding movable blades1117c. Thus, the rotation of the movable blades1117cis restricted and stopped by the stoppers1117e, and thus the wedge1172can be inserted into the notch1171a. The remaining structures of the eleventh embodiment are similar to those of the first embodiment.

Advantageous Effects of Eleventh Embodiment

According to the eleventh embodiment, similarly to the first embodiment, the impeller1117is operable to rotate together with the first arm8and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot1100can be reduced or prevented.

According to the eleventh embodiment, as described above, the impeller1117includes the plate-shaped movable blades1117cthat are tilted in the first rotation direction of the impeller1117when the impeller1117rotates in the second rotation direction of the impeller1117, and are tilted in the second rotation direction of the impeller1117when the impeller1117rotates in the first rotation direction of the impeller1117. Accordingly, regardless of the rotation direction of the impeller1117, the air volume of the impeller1117can be maintained substantially constant when the rotation speed is the same, and thus the first motor2can be efficiently cooled by the impeller1117.

According to the eleventh embodiment, as described above, the impeller1117includes the stoppers1117dto maintain the tilted postures of the movable blades1117c. Accordingly, the air volume of the impeller1117can be more reliably maintained substantially constant, and thus the first motor2can be more efficiently cooled by the impeller1117. The remaining advantageous effects of the eleventh embodiment are similar to the advantageous effects of the first embodiment.

Twelfth Embodiment

The structure of a SCARA robot1200according to a twelfth embodiment is described with reference toFIGS.20to23. In the twelfth embodiment, an impeller1216includes movable blades1216c, unlike the fourth embodiment. In the twelfth embodiment, detailed description of the same or similar structures as those of the fourth embodiment is omitted.

The structure of the SCARA robot1200according to the twelfth embodiment of the present disclosure is described with reference toFIGS.20to23. The SCARA robot1200is an example of a “robot” in the claims.

Structure of SCARA Robot

The SCARA robot1200is a robot including arms that move in a horizontal direction. The SCARA robot1200includes a base301(seeFIG.8), a first motor2(seeFIG.8), a first speed reducer303(seeFIG.8), a second motor4(seeFIG.1), a second speed reducer5(seeFIG.1), a third motor6(seeFIG.1), a fourth motor7(seeFIG.1), a first arm8(seeFIG.8), a second arm9(seeFIG.1), and a working unit10(seeFIG.1). The first motor2is an example of a “motor” in the claims. Furthermore, the first speed reducer303is an example of a “speed reducer” in the claims.

Joint Structure Connecting Base to First Arm

In the SCARA robot1200according to the twelfth embodiment, the impeller1216described below is rotated as the first speed reducer303rotates such that the first motor2is cooled. Such a joint structure connecting the base301to the first arm8is described below in detail.

The SCARA robot1200includes the base301, the first motor2, the first speed reducer303, the first arm8, wiring11(seeFIG.8), a motor holder12(seeFIG.8), an oil seal13(seeFIG.8), a stay14(seeFIG.8), a clamp15(seeFIG.8), the impeller1216, and a shaft cover417(seeFIG.8).

As shown inFIGS.20and21, the impeller1216is an axial flow impeller. The impeller1216includes an outer frame1216a, a rotation shaft1216b, a plurality of (two) movable blades1216c, a plurality of (two) stoppers1216d, and stoppers1216e.

The outer frame1216ais a frame that accommodates the plurality of movable blades1216c. The plurality of movable blades1216care rotatably attached to the rotation shaft1216b.

As shown inFIGS.22and23, each of the plurality of movable blades1216crotates about the rotation shaft1216b. A weight M is attached to each of the plurality of movable blades1216c. The weight M is arranged on one side in a direction in which the rotation shaft1216bextends.

When the impeller1216rotates in a first rotation direction of the impeller1216, an end of each of the plurality of movable blades1216con the weight M side moves in a second rotation direction of the impeller1216due to an inertial force accompanying the rotation of the impeller1216and the fluid force of wind flowing between the plurality of movable blades1216c. Thus, each of the plurality of movable blades1216cis tilted in the second rotation direction. When the impeller1216rotates in the second rotation direction of the impeller1216, the end of each of the plurality of movable blades1216con the weight M side moves in the first rotation direction of the impeller1216due to an inertial force accompanying the rotation of the impeller1216and the fluid force of wind flowing between the plurality of movable blades1216c. Thus, each of the plurality of movable blades1216cis tilted in the first rotation direction. Each of the plurality of movable blades1216chas a thin plate shape.

Thus, the weight M is attached to one side of each of the plurality of movable blades1216csuch that air flowing through the impeller1216is directed to one side on which the weight M is arranged, in the direction in which the rotation shaft1216bextends.

As shown inFIGS.20and21, the stoppers1216dmaintain the tilted postures of the corresponding movable blades1216c. Specifically, each of the stoppers1216dincludes a notch1261, a wedge1262, a spring1263, and a shaft1264.

The notch1261is formed in the outer frame1216a. The notch1261is formed to match the shape of the wedge1262such that the wedge1262can be inserted therein. The wedge1262restricts rotation of the movable blade1216cby being inserted into the notch1261. The wedge1262moves outward in the radial direction of the impeller1216due to a centrifugal force exerted on the mass of the movable blade1216caccompanying rotation of the rotation shaft1216b. The spring1263is attached to the shaft1264. The spring1263urges the movable blade1216cinserted into the notch1261inward in the radial direction of the impeller1216. The shaft1264positions the movable blade1216cin order to insert the wedge1262into the notch1261.

As shown inFIGS.22and23, the stoppers1216erestrict rotation of the corresponding movable blades1216c. Thus, rotation of the movable blades1216cis restricted and stopped by the stoppers1216e, and thus the wedge1262can be inserted into the notch1261. The remaining structures of the twelfth embodiment are similar to those of the first embodiment.

Advantageous Effects of Twelfth Embodiment

According to the twelfth embodiment, similarly to the fourth embodiment, the impeller1216is operable to rotate together with the first speed reducer303and generate wind to cool the first motor2. Accordingly, an increase in the number of components required to cool the first motor2and the complexity of the structure of the SCARA robot1200can be reduced or prevented. The remaining advantageous effects of the twelfth embodiment are similar to the advantageous effects of the fourth embodiment.

Modified Examples

For example, while the example in which the impeller17is attached to the first arm8in the joint structure connecting the base1to the first arm8has been shown in each of the aforementioned first, second, seventh, and eighth embodiments, the present disclosure is not restricted to this. In the present disclosure, the impeller may be attached to the second arm in a joint structure connecting the first arm to the second arm.

While the example in which the “robot” in the claims is a SCARA robot100(200,300,400,500,600,700,800,900,1000,1100,1200) has been shown in each of the aforementioned first to twelfth embodiments, the present disclosure is not restricted to this. In the present disclosure, the robot may be a vertical articulated robot or a single-axis robot.

While the example in which the weight M is attached to one side of each of the plurality of movable blades1216csuch that air flowing through the impeller1216is directed to one side on which the weight M is arranged, in the direction in which the rotation shaft1216bextends has been shown in the aforementioned twelfth embodiment, the present disclosure is not restricted to this. In the present disclosure, as in a first modified example shown inFIGS.24and25, a weight M may be attached to another side of each of a plurality of movable blades1316csuch that air flowing through an impeller1316is directed to another side on which the weight M is arranged, in a direction in which a rotation shaft extends.

While the example in which the weight M is attached to each of the plurality of movable blades1216chas been shown in the aforementioned twelfth embodiment, the present disclosure is not restricted to this. In the present disclosure, as in a second modified example shown inFIGS.26and27, instead of attaching a weight, one side of each of a plurality of movable blades1416cmay be made longer than another side of each of the plurality of movable blades1416c. Alternatively, as in a third modified example shown inFIGS.28and29, instead of attaching a weight, another side of each of a plurality of movable blades1516cmay be made longer than one side of each of the plurality of movable blades1516c.

While the example in which the motor holder12does not include cooling fins has been shown in each of the aforementioned first to eighth embodiments, the present disclosure is not restricted to this. In the present disclosure, as in a fourth modified example shown inFIG.30, a SCARA robot1600may include a motor holder1612including convex cooling fins1612aarranged in an air passage W. Accordingly, a first motor2can be cooled by the cooling fins1612aof the motor holder1612, and thus the first motor2can be more effectively cooled.

While the example in which the first motor2(motor) and the motor cover517are in contact with each other via the thermal conductor518has been shown in the aforementioned fifth embodiment, the present disclosure is not restricted to this. In the present disclosure, the motor and the motor cover may be in direct contact with each other. Accordingly, the motor can be cooled by the motor cover, and thus the motor can be effectively cooled.

While the example in which the first speed reducer3(speed reducer) is an RV speed reducer has been shown in each of the aforementioned first to ninth, eleventh, and twelfth embodiments, the present disclosure is not restricted to this. In the present disclosure, the speed reducer may be a cyclo speed reducer (registered trademark).