APPARATUS, APPARATUS CONTROL METHOD, ARTICLE MANUFACTURING METHOD, APPARATUS ASSEMBLY METHOD, ROBOT, AUTOMOBILE, AND RECORDING MEDIUM

An apparatus includes a support having two portions, and a unit including a speed reducer, a motor provided on the speed reducer, and a bearing provided on the speed reducer, the speed reducer, the motor, and the bearing being integrally assembled with each other and mounted on the two portions.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a technology of an apparatus.

Description of the Related Art

As an apparatus, for example, a plurality of mechanical components such as a motor, a speed reducer, and a bearing are arranged at a joint of a robot as disclosed in JP 2016-196054 A.

SUMMARY OF THE INVENTION

According to a first aspect of the present disclosure, an apparatus includes a support having two portions, and a unit including a speed reducer, a motor provided on the speed reducer, and a bearing provided on the speed reducer, the speed reducer, the motor, and the bearing being integrally assembled with each other and mounted on the two portions.

According to a second aspect of the present disclosure, a method of assembling an apparatus including a support having two portions, the method including fixing a speed reducer and a motor to a first member such that the speed reducer and the motor are positioned, fixing the speed reducer and a bearing to a second member such that the speed reducer and the bearing are positioned, and supporting the first member and the bearing by the two portions of the support.

DESCRIPTION OF THE EMBODIMENTS

An apparatus has been required to operate with high reproducibility and high accuracy. For this reason, mechanical components disposed in the apparatus are required to be assembled to each other with high accuracy.

The present disclosure improves accuracy of an operation performed by an apparatus.

First Embodiment

FIG.1is an explanatory view illustrating a configuration of a robot system1000according to a first embodiment.FIG.2is a block diagram illustrating a control system of the robot system1000according to the first embodiment. The robot system1000includes a robot10, a control device20, and a teaching pendant30that is an example of an operation device. The robot10is, for example, an industrial robot, and is a so-called manipulator. The robot10and the control device20are connected to each other by, for example, a cable so as to be able to transmit data. The control device20and the teaching pendant30are connected to each other by, for example, a cable so as to transmit data.

The control device20is for controlling an operation of the robot10, and is implemented by, for example, a computer. The teaching pendant30is an input device operable by a user, has a function of transmitting an operation command to the control device20by being operated by the user, and can operate the robot10according to a user operation. The control device20is configured to operate the robot10according to an operation command of a robot program or an operation command from the teaching pendant30.

A root of the robot10is a fixed end, and is fixed to a frame (not illustrated) or the like. A distal end of the robot10is a free end. The robot10includes a robot arm101and a robot hand102that is an example of an end effector attached to the robot arm101. InFIG.1, the robot hand102is not illustrated.

The robot arm101is a robot arm having six joints J1to J6. The robot arm101is, for example, a vertically articulated robot arm. The number of joints is not limited to six, and may be seven, for example. The robot arm101includes a base110that is a fixed link and a plurality of links111to116that are movable links. The base110and the links111to116are connected by the joints J1to J6, so that each of the links111to116is rotatable by each of the joints J1to J6.

A motor serving as a drive source is disposed in each of the joints J1to J6. When the motors provided in the joints J1to J6drive the joints J1to J6, that is, the links111to116, the robot10can take various postures. A tool center point (TCP) is defined at the distal end of the robot10, and the robot10can be operated in various postures by designating a position and posture of the TCP. Each of the joints J1to J6is a rotary joint, but the present technology is not limited thereto, and for example, any joint may be a linear motion joint.

The robot hand102is configured to be able to hold a workpiece. In a production line for manufacturing an article, the robot10can hold the workpiece with the robot hand102to perform conveyance work, assembly work for assembling to another workpiece, and can hold a tool to perform processing work for the workpiece. Alternatively, the robot10can perform work by mounting an actuator other than the robot hand102on the link116according to a work content of a manufacturing process.

For example, workpieces W1and W2are arranged around the robot10. By causing the robot10to hold the workpiece W1and causing the robot10to assemble the workpiece W1to the workpiece W2, an article as an assembly can be manufactured. The assembly may be an intermediate product or a final product. In a case where an article to be manufactured is a precision article, the robot10is required to perform highly accurate positioning control with high reproducibility.

The teaching pendant30includes an input unit that is an input device and a touch panel display304that also serves as a display unit that is a display device. A user interface (UI) image is displayed on the touch panel display304. In the teaching pendant30, the input unit and the display unit may be configured separately.

As illustrated inFIG.2, the control device20is implemented by a computer, and includes a central processing unit (CPU)201that is a processor. In addition, the control device20includes a read only memory (ROM)202, a random access memory (RAM)203, and a hard disk drive (HDD)204as storage devices. In addition, the control device20includes a recording disk drive205and an input/output (I/O)206that is an input/output interface. The CPU201, the ROM202, the RAM203, the HDD204, the recording disk drive205, and the I/O206are connected to each other via a bus210so as to be able to transmit data.

The ROM202stores a basic program read by the CPU201at the time of starting the computer. The RAM203is a transitory storage device used for arithmetic processing of the CPU201. The HDD204is a storage device that stores various types of data such as an arithmetic processing result of the CPU201. In the first embodiment, the HDD204stores a program211to be executed by the CPU201. The CPU201controls the robot10by executing the program211. The recording disk drive205can read various types of data, programs, and the like recorded in a recording disk212. The robot arm101, the robot hand102, and the teaching pendant30are connected to the I/O206.

The teaching pendant30is implemented by a computer and includes a CPU301that is a processor. The teaching pendant30includes a ROM302and a RAM303as storage devices. The teaching pendant30includes a touch panel display304and an I/O306as an input/output interface. The CPU301, the ROM302, the RAM303, the touch panel display304, and the I/O306are connected to each other via a bus310so as to be able to transmit data.

The ROM302stores a program311to be executed by the CPU301. The CPU301executes a control method described below by executing the program311. The RAM303is a transitory storage device used for arithmetic processing of the CPU301. The I/O306is connected to the I/O206of the control device20.

The robot arm101includes six drivers160corresponding to the joints J1to J6and six drive modules450corresponding to the joints J1to J6. Each drive module450is disposed in each of the joints J1to J6.FIG.2illustrates one of the six drivers160and one of the six drive modules450.

Hereinafter, the joint J2among the plurality of joints J1to J6will be described, and the other joints J1and J3to J6have substantially the same configuration as the joint J2, and thus a description thereof will be omitted.

The drive module450includes a motor151, an encoder155, and a torque sensor451. The driver160includes a microcomputer (not illustrated), an A/D conversion circuit (not illustrated), a motor drive circuit (not illustrated), and the like. The driver160is connected to the I/O206of the control device20via a bus140.

The motor151is an electric motor and is a drive source that drives the joint J2. The motor151drives the distal end side link112of the two links111and112connected by the joint J2with respect to the proximal end side link111via a transmission mechanism including a speed reducer described below.

The torque sensor451is an example of a force sensor that detects a force (torque) acting on the joint J2, that is, a force (torque) acting on the link112with respect to the link111, and outputs a signal indicating a force value (torque value) that is a detection result to the driver160. The encoder155is a rotary encoder, detects a rotation angle of a motor shaft of the motor151, and outputs a signal indicating an encoder value that is a detection result to the driver160.

The driver160takes in a signal from the torque sensor451at a predetermined cycle, converts the signal into a digital signal indicating the force value (torque value), and outputs the digital signal to the control device20. Further, the driver160takes in and counts an encoder signal from the encoder155, and outputs the counted value to the control device20. The control device20controls the robot10based on the detection results.

In the first embodiment, a non-transitory computer-readable recording medium is the HDD204, and the program211is stored in the HDD204, but the present technology is not limited thereto. The program211may be recorded in any recording medium as long as the recording medium is a non-transitory computer-readable recording medium. For example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a magnetic tape, a non-volatile memory, or the like can be used as the recording medium for storing the program211.

In the first embodiment, the program311is stored in the ROM302, but the present technology is not limited thereto. The program311may be recorded in any recording medium. For example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a magnetic tape, a non-volatile memory, or the like can be used as the recording medium for storing the program311.

In addition, the storage device included in the control device20is the HDD204, but is not limited thereto, and the storage device included in the control device20may be, for example, a solid state drive (SSD). Similarly, the storage device included in the teaching pendant30is the ROM302, but is not limited thereto, and the storage device included in the teaching pendant30may be an SSD.

The control device20or the teaching pendant30may be connected to a network. Furthermore, the robot10and the control device20, or the control device20and the teaching pendant30may be connected by a network.

Hereinafter, a joint structure of the joint J2will be described in detail.FIG.3is a cross-sectional view of a joint structure400according to the first embodiment. The joint structure400of the first embodiment includes the link111, the link112, and the drive module450. The link111is an example of a support. Furthermore, the link111is an example of a first link, and the link112is an example of a second link.

The drive module450includes a drive unit150that is an example of a unit, and the torque sensor451that is an example of the force sensor. The drive unit150is supported by the link111. The link112is supported by the drive unit150so as to be rotationally driven about an axis C0by the drive unit150with respect to the link111.

The drive unit150includes the motor151, a speed reducer152, and a bearing153. The motor151is provided on an input side of the speed reducer152, and the bearing153is provided on an output side of the speed reducer152. The motor151is a drive source of the joint J2, and drives the link112via the speed reducer152. The bearing153is disposed between the link111and the drive unit150. The speed reducer152is preferably, for example, a wave gearing speed reducer. The bearing153is, for example, a cross roller bearing, and includes a plurality of rollers1530, an outer ring1531, and an inner ring1532. The bearing153is not limited to this configuration. For example, the bearing153may be a sliding bearing such as a deep groove ball bearing, a needle-shaped roller bearing, a rolling bearing, a radial ball bearing, a radial roller bearing, or an oil-free bearing.

In the first embodiment, the inner ring1532of the bearing153is disposed to face the link111, and the outer ring1531of the bearing153is disposed to face the drive unit150. The motor151, the speed reducer152, and the bearing153become frictional resistance when axes thereof are misaligned from each other. Therefore, in order to cause the robot10to perform precise work, it is required to position the motor151, the speed reducer152, and the bearing153with high accuracy, that is, to align the axes of the motor151, the speed reducer152, and the bearing153with each other.

FIG.26is an explanatory diagram of a joint structure of a comparative example. A link112X is rotationally driven by a motor151X with respect to a link111X via a speed reducer152X. The link111X includes two members (portions)1111X and1112X, and a U-shaped portion is formed by fastening the member1111X to the member1112X with a fastening member181X. The motor151X and the speed reducer152X are positioned at and fixed to the member1111X, and a bearing153X is positioned at and fixed to the member1112X. When adjusting axial positions of the motor151X, the speed reducer152X, and the bearing153X, the member1112X is moved in a direction orthogonal to the axis with respect to the member1111X. After the axial positions are adjusted, the fastening member181X is fastened in a direction parallel to the axis to fix the member1112X to the member1111X. In this manner, by sliding the member1112X with respect to the member1111X, the motor151X, the speed reducer152X, and the bearing153X can be adjusted to be axially aligned. However, the member1111X needs to be provided with an adjustment margin in an adjustment direction, and the link111X is required to have high stiffness. For this reason, it is necessary to make a fastening portion of the member1111X of the link111X thick in the adjustment direction. As a result, in the joint structure of the comparative example, the link111X, that is, the robot, increases in size and weight.

The link111of the first embodiment has a U-shaped portion1110having a U shape. The drive module450is disposed in the U-shaped portion1110. That is, the drive unit150and the torque sensor451are disposed in the U-shaped portion1110. The torque sensor451is disposed between the drive unit150and the link112so that a torque acting on the link112with respect to the link111can be detected.

The motor151, the speed reducer152, and the bearing153are integrally assembled with each other via a plurality of members to be unitized. As a result, the motor151, the speed reducer152, and the bearing153are unitized (that is, integrated) while being axially aligned with each other. The motor151, the speed reducer152, and the bearing153may be unitized before the motor151, the speed reducer152, and the bearing153are mounted on the link111, or may be unitized while being mounted on the link111, that is, while the drive unit150is fixed to the link111.

In the first embodiment, the drive unit150is mounted on the U-shaped portion1110so as to be integrally detachable from the U-shaped portion1110of the link111. In other words, the drive unit150is unitized, that is, integrated, and attached to the link111so as to be detachable from the link111in an integrated state.

As described above, in the first embodiment, the motor151, the speed reducer152, and the bearing153can be axially aligned when the drive unit150is assembled, and it is not necessary to perform axial alignment with the link111X as in the comparative example. Therefore, it is not necessary to increase the size and weight of the link111unlike the link111X of the comparative example, the link111can be reduced in size and weight, and the motor151, the speed reducer152, and the bearing153can be axially aligned with high accuracy. Therefore, it is possible to cause the robot10to perform highly accurate positioning control with high reproducibility. In the first embodiment, the link111is integrally molded. Therefore, it is possible to reduce the size and weight of the link111while securing stiffness necessary for the link111. Then, it is sufficient if the drive unit150including the motor151, the speed reducer152, and the bearing153that are axially aligned is mounted on the link111. As the motor151, the speed reducer152, and the bearing153are axially aligned, performance and durability of the motor151, the speed reducer152, and the bearing153can be improved. In addition, frictional resistance caused by axial misalignment of the motor151, the speed reducer152, and the bearing153can be reduced, and positioning control of the robot10can be performed with high accuracy. That is, it is possible to cause the robot10to perform highly accurate operation with high reproducibility.

FIG.4is a cross-sectional view of the drive unit150according to the first embodiment.FIG.5is an exploded cross-sectional view of the drive unit150according to the first embodiment.

The drive unit150of the first embodiment further includes a positioning member161that is an example of a first member and a positioning member162that is an example of a second member. The positioning member161is disposed on the input side of the speed reducer152, and the positioning member162is disposed on the output side of the speed reducer152. The positioning member161includes a flange portion1613directly or indirectly connected to the link111. The link112is indirectly connected to the positioning member162via the torque sensor451. That is, the torque sensor451is disposed between the positioning member162and the link112.

The motor151and the speed reducer152are axially aligned by the positioning member161, and the speed reducer152and the bearing153are axially aligned by the positioning member162. That is, the axis of the motor151, the axis of the speed reducer152, and the axis of the bearing153are aligned with the axis C0by the positioning members161and162. Therefore, the axis C0is also the axis of the speed reducer152, that is, the axis of the drive unit150. The axis C0becomes a rotation axis of the joint J2by assembling the drive unit150to the joint J2.

In the first embodiment, the drive unit150further includes a brake154, the encoder155, and oil seals156and157. In the first embodiment, the plurality of members151to157are members that need to be axially aligned with each other. The members151to157are integrally assembled so as to be axially aligned with each other. By axially aligning the members151to157, performance and durability of each of the members151to157can be improved. In addition, frictional resistance caused by axial misalignment of the members151to157can be reduced, and positioning control of the robot10can be performed with high accuracy. That is, it is possible to cause the robot10to perform highly accurate operation with high reproducibility. The drive unit150may include members that need to be axially aligned with each other in addition to the members151to157.

Hereinafter, a method of assembling the drive unit150will be described in detail.FIGS.6A to16Bare explanatory views of the method of assembling the drive unit150according to the first embodiment.

First, as illustrated inFIGS.6A and6B, a stator1513is fitted to a reference surface1611of the positioning member161, and the stator1513is attached to the positioning member161. The reference surface1611is a surface based on the axis C0. The reference surface1611has a cylindrical shape and can be easily formed by a general-purpose processing machine (not illustrated).FIG.6Aillustrates a state before the stator1513is attached to the positioning member161, andFIG.6Billustrates a state after the stator1513is attached to the positioning member161.

As illustrated inFIGS.7A and7B, a motor shaft1511is attached to a rotor1512.FIG.7Aillustrates a state before the motor shaft1511is attached to the rotor1512, andFIG.7Billustrates a state after the motor shaft1511is attached to the rotor1512.

As illustrated inFIGS.8A and8B, an encoder stay1514has a reference surface1517on which a motor bearing1515is positioned. The reference surface1517is a cylindrical surface, and can be easily formed by a general-purpose processing machine (not illustrated). The motor bearing1515is fitted to the reference surface1517of the encoder stay1514. Then, the encoder stay1514and the motor bearing1515are attached to the motor shaft1511, and the motor shaft1511is inserted into the positioning member161such that the rotor1512is disposed inside the stator1513.FIG.8Aillustrates a state before the positioning member161and the members1511to1515of the motor are assembled, andFIG.8Billustrates a state after the positioning member161and the members1511to1515of the motor are assembled.

Next, as illustrated inFIGS.9A and9B, a motor bearing1516is attached to a reference surface1612of the positioning member161. The reference surface1612is a surface based on the axis C0. The reference surface1612is a cylindrical surface, and can be easily formed by a general-purpose processing machine (not illustrated). As a result, the motor bearing1516is positioned by the positioning member161. When the motor shaft1511is inserted into the motor bearing1516, the motor shaft1511is positioned by the positioning member161via the motor bearing1516, whereby the encoder stay1514is positioned by the positioning member161via the motor shaft1511and the motor bearing1515. That is, the members1511to1516of the motor151are positioned by the positioning member161such that the axes of the members1511to1516of the motor151are aligned with the axis C0.

In the first embodiment, the members1511to1516form the motor151.FIG.9Aillustrates a state before the positioning member161and the members1511to1516of the motor are assembled, andFIG.9Billustrates a state after the positioning member161and the members1511to1516of the motor are assembled. The positioning member161is formed in a cup shape, the rotor1512and the stator1513are disposed inside the positioning member161, and the motor shaft1511is disposed across the inside and the outside of the positioning member161. In this manner, the positioning member161also functions as a housing that houses the rotor1512and the stator1513of the motor151.

Next, as illustrated inFIGS.10A and10B, the encoder155is attached to the encoder stay1514and the motor shaft1511. The encoder155is attached to the motor shaft1511to be positioned by the positioning member161via the motor shaft1511. That is, the encoder155is positioned by the positioning member161such that the axis of the encoder155is aligned with the axis C0.FIG.10Aillustrates a state before the encoder155is attached to the encoder stay1514, andFIG.10Billustrates a state after the encoder155is attached to the encoder stay1514.

Next, as illustrated inFIGS.11A and11B, the oil seal156is attached to the positioning member161. Therefore, the oil seal156is supported by the positioning member161. The oil seal156is an example of a first oil seal. The oil seal156is provided such that a lip of the oil seal156is in contact with the motor shaft1511. As a result, the oil seal156is positioned by the positioning member161via the motor bearing1516and the motor shaft1511. The oil seal156positioned on the input side of the speed reducer152can reduce leakage of oil of the speed reducer152described below from the input side of the speed reducer152to the rotor1512and the stator1513via the motor shaft1511. The positioning member161may be provided with a fitting portion, and the oil seal156may be directly positioned by the positioning member161by being fitted to the fitting portion.FIG.11Aillustrates a state before the oil seal156is attached to the positioning member161, andFIG.11Billustrates a state after the oil seal156is attached to the positioning member161.

As described above, the members151,155, and156on the input side of the speed reducer152are supported by the positioning member161in a state of being positioned by the positioning member161.

Next, as illustrated inFIGS.12A and12B, the speed reducer152is attached to the positioning member161. The speed reducer152includes an input unit1521, an output unit1522, and a fixing portion1520. The input unit1521and the output unit1522rotate with respect to the fixing portion1520. In addition, the output unit1522is decelerated at a predetermined deceleration ratio with respect to the input unit1521and rotates.FIG.12Aillustrates a state before the speed reducer152is attached to the positioning member161, andFIG.12Billustrates a state after the speed reducer152is attached to the positioning member161.

In the first embodiment, the fixing portion1520of the speed reducer152is fixed to the positioning member161by a fastening member171. When the input unit1521of the speed reducer152is fitted to the motor shaft1511, the speed reducer152is positioned by the positioning member161via the motor shaft1511. That is, the speed reducer152is positioned by the positioning member161such that the axis of the speed reducer152is aligned with the axis C0.

As described above, the motor151and the speed reducer152are fixed to the positioning member161in a state where the motor151and the speed reducer152are positioned by the positioning member161such that the axes of the motor151and the speed reducer152are aligned with the axis C0.

Next, as illustrated inFIGS.13A and13B, the oil seal157is attached to a reference surface1621of the positioning member162. The reference surface1621has a cylindrical shape and can be easily formed by a general-purpose processing machine (not illustrated). Therefore, the oil seal157is supported by the positioning member162. The oil seal157is an example of a second oil seal.FIG.13Aillustrates a state before the oil seal157is attached to the positioning member162, andFIG.13Billustrates a state after the oil seal157is attached to the positioning member162.

Next, as illustrated inFIGS.14A and14B, the positioning member162is attached to the speed reducer152.FIG.14Aillustrates a state before the positioning member162is attached to the speed reducer152, andFIG.14Billustrates a state after the positioning member162is attached to the speed reducer152.

In the first embodiment, the positioning member162is fixed to the output unit1522of the speed reducer152by fastening members172. The positioning member162has a reference surface1622, and the positioning member162and the speed reducer152are positioned by fitting the reference surface1622to the output unit1522of the speed reducer152. That is, the positioning member162is fixed to the output unit1522of the speed reducer152such that the axis of the positioning member162is aligned with the axis C0. The reference surface1622is a cylindrical surface, and can be easily formed by a general-purpose processing machine (not illustrated).

The oil seal157is provided such that a lip of the oil seal157is in contact with the motor shaft1511. The oil seal157is positioned by the positioning member161via the motor shaft1511. The oil seal157positioned on the output side of the speed reducer152can reduce leakage of the oil of the speed reducer152from the output side of the speed reducer152to the brake154described below via the motor shaft1511.

As described above, since the axes of the oil seals156and157are aligned with the axis C0, the oil seal156provided on the input side of the speed reducer152and the oil seal157provided on the output side of the speed reducer152can effectively reduce leakage of the oil (grease) from the speed reducer152to the outside. Further, since a pressure of the lip of each of the oil seals156and157is uniform, it is possible to reduce friction between the oil seals156and157and the motor shaft1511from fluctuating. In addition, since it is possible to reduce leakage of the oil (grease) by the oil seals156and157and to reduce fluctuation of the friction between the oil seals156and157and the motor shaft1511, it is possible to prevent deterioration of detection accuracy of the encoder155and the torque sensor145.

Next, as illustrated inFIGS.15A and15B, the brake154is attached to the motor shaft1511and the positioning member162. As a result, the brake154is positioned by the positioning member162.FIG.15Aillustrates a state before the brake154is attached to the motor shaft1511, andFIG.15Billustrates a state after the brake154is attached to the motor shaft1511.

Next, as illustrated inFIGS.16A and16B, the bearing153is attached to the positioning member162.FIG.16Aillustrates a state before the bearing153is attached to the positioning member162, andFIG.16Billustrates a state after the bearing153is attached to the positioning member162.

The positioning member162has a reference surface1623. The reference surface1623is a surface based on the axis C0. The reference surface1623is a cylindrical surface, and can be easily formed by a general-purpose processing machine (not illustrated). The bearing153is positioned by the positioning member162by being fitted to the reference surface1623of the positioning member162. That is, the bearing153is positioned by the positioning member162such that the axis of the bearing is aligned with the axis C0.

In the first embodiment, the outer ring1531of the bearing153is attached to the reference surface1623of the positioning member162. That is, the outer ring1531of the bearing153is supported by the positioning member162.

As described above, the bearing153, the brake154, and the oil seal157provided on the output side of the speed reducer152are supported by the positioning member162in a state of being positioned by the positioning member162. That is, the speed reducer152, the bearing153, the brake154, and the oil seal157are fixed to the positioning member162in a state where the speed reducer152, the bearing153, the brake154, and the oil seal157are positioned by the positioning member162such that the axes of the speed reducer152, the bearing153, the brake154, and the oil seal157are aligned with the axis C0.

The positioning member162is fixed to the output unit1522of the speed reducer152by the plurality of fastening members172arranged in a circumferential direction around the axis C0. An outer diameter D2of the bearing153is preferably larger than a diameter D1of an imaginary circle passing through the centers of the plurality of fastening members172. This facilitates assembling work for the positioning member162and the speed reducer152.

FIG.16Billustrates the drive unit150assembled as described above. Since the axes of the members151to157included in the drive unit150are aligned with the axis C0by the positioning members161and162, it is not necessary to perform axial alignment work when the drive unit150is assembled to the link111.

Next, a method of assembling the joint J2of the robot10will be described.FIG.17is an explanatory view of the method of assembling the joint J2of the robot10according to the first embodiment.

The U-shaped portion1110includes a base portion1113and a pair of support portions1111and1112disposed on the base portion1113while being spaced apart from each other in an X direction. The support portions1111and1112are two portions that form a part of the U-shaped portion1110. The X direction is an example of a predetermined direction, and is a direction along the axis C0. In the X direction, one direction is defined as a +X direction, and a direction opposite to the +X direction is defined as a −X direction. The +X direction is a direction from the support portion1112toward the support portion1111. The −X direction is a direction from the support portion1111toward the support portion1112. The support portion1111includes an annular portion1115in which the drive unit150is disposed. The support portion1112includes an annular portion1116in which the drive unit150is disposed.

FIG.18Ais a side view of the link111when the link111according to the first embodiment is viewed in the −X direction.FIG.18Bis a side view of the drive unit150when the drive unit150according to the first embodiment is viewed in the +X direction. The annular portion1115illustrated inFIG.18Ahas an opening through which the drive unit150illustrated inFIG.18Bcan pass.

As illustrated inFIG.17, the drive unit150is moved in the −X direction to pass through the opening of the annular portion1115of the support portion1111, and the drive unit150is disposed between the pair of support portions1111and1112. Then, the flange portion1613of the positioning member161is fixed to the annular portion1115of the support portion1111by a fastening member181. Further, a coupling member183is fitted to the inner ring1532of the bearing153of the drive unit150, and the coupling member183is fixed to the annular portion1116of the support portion1112by a fastening member182. At this time, the coupling member183and the inner ring1532of the bearing153are preferably fitted by transition fitting or interference fitting.

The coupling member183has a connection surface connected to the link111and a reference surface connected to the inner ring1532of the bearing153. The reference surface is a cylindrical surface, and the connection surface is an annular surface. The coupling member183can be formed by a general-purpose processing machine.

Then, the link112is fixed to the positioning member162via the torque sensor451, whereby the assembly of the joint J2is completed.

As described above, the positioning member161is supported by the support portion1111of the link111by fixing the flange portion1613of the positioning member161to the link111, and the inner ring1532of the bearing153is supported by the support portion1112of the link111by fixing the inner ring1532of the bearing153to the link111via the coupling member183. As a result, the drive unit150is supported by the pair of support portions1111and1112as illustrated inFIG.3.

The reference surfaces of the positioning member161, the positioning member162, the encoder stay1514, and the coupling member183can be formed by a general-purpose processing machine (not illustrated) as described above. Examples of the general-purpose processing machine include two types of processing machines: a milling machine and a lathe.

The milling machine flattens the surface by moving an end mill in parallel while rotating the end mill, and can perform flat machining with high accuracy. In addition, the milling machine can process a plurality of surfaces having steps with high precision parallelism by stably pressing a workpiece.

Since the lathe cuts a workpiece while rotating the workpiece, it is possible to perform machining with high dimensional accuracy using a rotation axis as a datum axis. Therefore, the lathe can process a plurality of surfaces perpendicular to the rotation axis with high precision parallelism, and can process a plurality of cylindrical surfaces on the rotation axis with high coaxiality. Further, it is possible to achieve high perpendicularity between the plurality of surfaces perpendicular to the rotation axis, and cylindrical surfaces along the rotation axis with high dimensional accuracy.

As described above, the reference surfaces of the positioning member161, the positioning member162, and the coupling member183can be processed with high accuracy by a general-purpose processing machine. Therefore, the oil seal156, the motor151, and the encoder155can be assembled to the fixing portion1520of the speed reducer152with high assembly accuracy via the positioning member161. The oil seal157, the brake154, and the bearing153can be assembled to the output unit1522of the speed reducer152with high assembly accuracy via the positioning member162. Furthermore, the coupling member183can be assembled following the bearing153.

That is, the motor151, the encoder155, the brake154, the bearing153, and the oil seals156and157can be assembled with high assembly accuracy such that the axes thereof are aligned with the axis C0that is the rotation axis of the speed reducer152. Therefore, the drive unit150can be assembled with high accuracy, and the drive unit150can be caused to function as a rotary joint with compensated accuracy.

Meanwhile, the pair of support portions1111and1112of the link111do not need to have a highly accurate positional relationship with each other unlike the link111X of the comparative example. That is, parallelism of the pair of support portions1111and1112and coaxiality and size tolerance (fitting tolerance) of the annular portions1115and1116in which the drive unit150is disposed do not need to be as highly accurate as the drive unit150.

Since the accuracy of the joint J2is compensated by the drive unit150, the drive unit150can be installed in the U-shaped portion1110of the link111to function as the joint J2of the robot10. A relative position error between the two support portions1111and1112is absorbed by an allowable inclination, an internal gap, or a fitting gap of the bearing153itself.

Next, a method of manufacturing the link111according to the first embodiment will be described.FIG.19Ais a perspective view of the link111according to the first embodiment. As described above, the link111has the U-shaped portion1110. The U-shaped portion1110includes the base portion1113and the two support portions1111and1112.

Here, the X direction, a Y direction, and a Z direction orthogonal to each other are defined. The X direction is a direction along the axis C0as described above, and the pair of support portions1111and1112are spaced apart from each other in the X direction. The X direction is also a thickness direction of the support portions1111and1112. The Z direction is a longitudinal direction of the support portions1111and1112, and the Y direction is a lateral direction of the support portions1111and1112. The Z direction is also a height direction of each of the support portions1111and1112. The Y direction is also a direction parallel to the base portion1113and a width direction of each of the support portions1111and1112. A first end of the support portion1111in the Z direction is a fixed end connected to the base portion1113, and a second end of the support portion1111in the Z direction is an open end. A first end of the support portion1112in the Z direction is a fixed end connected to the base portion1113, and a second end of the support portion1112in the Z direction is an open end. A direction in which the U-shaped portion1110is opened is the +Z direction.

In the Z direction, a direction from the open ends of the support portions1111and1112toward the base portion1113is defined as a −Z direction, and a direction from the base portion1113toward the open ends of the support portions1111and1112opposite to the −Z direction is defined as a +Z direction. In the Y direction, one direction is defined as a +Y direction, and a direction opposite to the +Y direction is defined as a −Y direction. As described above, one direction of the X direction is defined as the +X direction, and a direction opposite to the +X direction is defined as the −X direction.FIG.19Bis a side view of the link111when the link111according to the first embodiment is viewed in the −X direction.

In the first embodiment, the link111is manufactured by integral molding using a mold. A material of the link111may be a resin or metal.FIG.19Cis a cross-sectional view of the link111according to the first embodiment.FIG.19Cis a cross-sectional view of the link111taken along line XIXC-XIXC inFIG.19B.FIG.19Dis an explanatory view of the method of manufacturing the link111according to the first embodiment.FIG.19Dis a front view of the link111when the link111is viewed in the +Y direction.

A mold (not illustrated) is tightened to inject a molten material into a cavity in the mold, the mold is cooled, and then the mold is opened to remove the link111from the mold.

Each of the support portions1111and1112has a draft angle such that a part M1of the mold positioned between the support portions1111and1112is removed in the +Z direction in a mold opening process. The support portion1111has a tapered surface S1forming the draft angle, and the support portion1112has a tapered surface S2forming the draft angle. The tapered surfaces S1and S2face each other in the X direction. The tapered surfaces S1and S2are inclined so as to be away from each other in the X direction toward the +Z direction. That is, the tapered surfaces S1and S2are inclined such that a distance between the tapered surfaces S1and S2increases as the distance from the base portion1113increases. An opening angle θ1of the tapered surfaces S1and S2is set to a predetermined angle such that the part M1of the mold is removed from between the support portions1111and1112.

As described above, according to the first embodiment, the support portions1111and1112of the link111do not need to have a highly accurate positional relationship with each other. That is, it is not necessary to provide a highly accurate positioning reference for the support portions1111and1112.

A force received by the support portions1111and1112from the drive unit150is transmitted to the base portion1113via the support portions1111and1112. By integrally molding the support portions1111and1112with the base portion1113, it is possible to form a transmission path for guiding the force straight from the support portions1111and1112in the −Z direction. Therefore, it is not necessary to make the U-shaped portion1110as stiff as the comparative example, and the U-shaped portion1110can be made thinner than the comparative example.

When the U-shaped portion1110is thinned, the support portions1111and1112can be thinned in the thickness direction of the support portions1111and1112and an axial direction of the drive unit150. In addition, a recess can be provided in the support portions1111and1112or the base portion1113.

As described above, it is possible to reduce the size and weight of the link111while ensuring moldability of the link111, assembly accuracy and assemblability of the joint J2, and the stiffness of the link111, and thus, it is possible to reduce the size and weight of the robot10and to reduce the cost related to the manufacturing of the robot10.

Since the axially aligned drive unit150is incorporated in the robot10, the robot10can be caused to perform highly accurate assembly work, and accuracy of an operation performed by the robot10can be improved. Furthermore, since durability of the robot10is improved, the cost required for maintenance can also be reduced.

Furthermore, according to the first embodiment, it is possible to cause the robot10to perform work that requires highly accurate positioning reproducibility and high-speed operation, such as assembly work with a minute load of several grams. Therefore, the robot10can be caused to perform high-mix low-volume production, a startup period of a production line in this case can be shortened, so that a startup cost of the production line can be reduced.

First Modified Example

The drive unit150may also be unitized in the middle of being assembled to the joint J2.FIG.20is an explanatory view of a method of assembling a joint J2according to a first modified example.

As illustrated inFIG.20, a positioning member161, a motor151, a speed reducer152, an encoder155, and an oil seal156are unitized to form a first unit, and a positioning member162, a bearing153, a brake154, and an oil seal157are unitized to form a second unit.

Then, the first unit is moved in the −X direction to pass through an opening of an annular portion1115of a support portion1111, and the first unit is disposed between the pair of support portions1111and1112. Then, a flange portion1613of a positioning member161is fixed to the annular portion1115of the support portion1111by a fastening member181. The second unit is disposed between the pair of support portions1111and1112by moving the second unit in the +X direction to pass through an opening of an annular portion1116of the support portion1112. The second unit is fixed to an output unit1522of the speed reducer152of the first unit by a fastening member172. Therefore, the assembly of the drive unit150is completed.

Further, a coupling member183is fitted to an inner ring1532of the bearing153of the drive unit150, and the coupling member183is fixed to the annular portion1116of the support portion1112by a fastening member182. As a result, the drive unit150is assembled to the link111.

Second Modified Example

In the first embodiment, a case where the motor151is assembled has been described as an example, but the present technology is not limited thereto.FIG.21is an explanatory view of a joint structure400A of a joint J2according to a second modified example.

The joint structure400A of the second modified example includes a drive unit150A and a torque sensor451. The drive unit150A includes a motor151A and a positioning member161A instead of the motor151and the positioning member161. A configuration of the drive unit150A other than the motor151A and the positioning member161A is similar to that of the drive unit150other than the motor151and the positioning member161, and thus a description thereof is omitted.

The motor151A is a component in which a rotor, a stator, and the like are integrated, and a general-purpose motor can be applied. The positioning member161A is an example of the first member, and the motor151A is attached to the positioning member161A. As described above, the motor151A may be an integrated component.

Third Modified Example

In the first embodiment, as illustrated inFIG.3, a case where the torque sensor451is disposed between the positioning member162and the link112has been described, but the present technology is not limited thereto.FIG.22is an explanatory view of a joint structure400B of a joint J2according to a third modified example.

The joint structure400B of the third modified example includes a drive unit150and a torque sensor451. The torque sensor451is disposed between a positioning member161of the drive unit150and a link111. As such, the torque sensor451may be disposed between the drive unit150and the link111. A link112may be directly connected to a positioning member162by a fastening member184.

Fourth Modified Example

In the first embodiment, as illustrated inFIG.3, a case where the torque sensor451is disposed between the positioning member162and the link112has been described, but the present technology is not limited thereto.FIG.23is an explanatory view of a joint structure400C of a joint J2according to a fourth modified example. The joint structure400C of the fourth modified example includes a drive unit150. That is, a torque sensor451may be omitted in the joint structure400C. A link112may be directly connected to a positioning member162by a fastening member184.

Fifth Modified Example

Next, a method of manufacturing a support according to a fifth modified example of the first embodiment will be described. In the fifth modified example, a link111that is a support is manufactured by integral molding using a mold.FIG.24Ais a side view of the link111when the link111according to the fifth modified example is viewed in the −X direction.FIG.24Bis a cross-sectional view of the link111according to the fifth modified example.FIG.24Bis a cross-sectional view of the link111taken along line XXIVB-XXIVB inFIG.24A.FIG.24Cis an explanatory view of a method of manufacturing the link111according to the fifth modified example.FIG.24Cis a front view of the link111when the link111is viewed in the +Y direction.

A mold (not illustrated) is tightened to inject a molten material into a cavity in the mold, the mold is cooled, and then the mold is opened to remove the link111from the mold.

Each of support portions1111and1112has a draft angle such that a part M11of a mold positioned between the support portions1111and1112is removed in the +Y direction and a part M12of a mold is removed in the −Y direction in a mold opening process. The support portion1111has tapered surfaces S11and S12forming draft angles, and the support portion1112has tapered surfaces S21and S22forming the draft angles. The tapered surfaces S11and S21face each other in the X direction. The tapered surfaces S12and S22face each other in the X direction.

The tapered surfaces S11and S21are inclined so as to be away from each other in the X direction toward the +Y direction. The tapered surfaces S12and S22are inclined so as to be away from each other in the X direction toward the −Y direction. That is, the tapered surface S11is inclined such that a distance to the tapered surface S21increases as the distance from a center C10of the support portion1111in the Y direction increases in the +Y direction, and the tapered surface S21is inclined such that a distance to the tapered surface S11increases as the distance from a center C20of the support portion1112in the Y direction increases in the +Y direction. Further, the tapered surface S12is inclined such that a distance to the tapered surface S22increases as the distance from the center C10of the support portion1111in the Y direction increases in the −Y direction, and the tapered surface S22is inclined such that a distance to the tapered surface S12increases as the distance from the center C20of the support portion1112in the Y direction increases in the −Y direction. An opening angle θ11 of the tapered surfaces S11and S21is set to a predetermined angle such that the part M11of the mold is removed in the +Y direction from between the support portions1111and1112. An opening angle θ12 of the tapered surfaces S12and S22is set to a predetermined angle such that the part M12of the mold is removed in the −Y direction from between the support portions1111and1112.

Sixth Modified Example

Next, a method of manufacturing a link111according to a sixth modified example of the first embodiment will be described. Although not illustrated, the link111can be molded without having a draft angle by using a molding method of decomposing a mold, such as gypsum casting, sand mold casting, or lost wax casting. With the molding methods, it is also possible to form an undercut in the link111. For example, a width of an inner bottom side of a U-shaped portion1110may be equal to or larger than a width of an inner opening side of the U-shaped portion1110.

Seventh Modified Example

In the first embodiment, a case where the link111that is a support is formed by integral molding has been described, but the present technology is not limited thereto. As long as a transmission path of a force from the support portions1111and1112to the base portion1113is straight as described in the first embodiment, the support portions1111and1112and the base portion1113may be configured as separate members.

FIG.25is a cross-sectional view of a link111E that is an example of a support according to a seventh modified example. The link111E has a U-shaped portion1110E having a U shape. The U-shaped portion1110E includes a base portion1113and a pair of support portions1111and1112, but the base portion1113and the pair of support portions1111and1112are formed as separate members.

The pair of support portions1111and1112are fastened to the base portion1113by fastening members191and192in a direction intersecting the X direction, that is, in the Z direction orthogonal to the X direction in the seventh modified example to be integrated with the base portion1113.

A force from a drive unit150received by the support portions1111and1112is transmitted to the base portion1113via the support portions1111and1112. By fixing the support portions1111and1112to the base portion1113in the Z direction by the fastening members191and192, it is possible to form a transmission path for guiding the force straight from the support portions1111and1112in the −Z direction as in the first embodiment.

Second Embodiment

Next, a second embodiment will be described in detail. The present disclosure is applicable not only to a robot but also to a drive device including a motor, a speed reducer, and a bearing. For example, the present disclosure is applicable to a drive device of an automobile. In the second embodiment, an electric vehicle will be described as an example.

FIG.27is an explanatory view of a drive structure2400of an automobile according to the second embodiment, the drive structure2400including a motor and a wheel.FIG.28is an explanatory view of a method of assembling the drive structure2400of the automobile according to the second embodiment, the drive structure2400including the motor and the wheel. In the following, the same reference numerals will be used for the same or corresponding configurations as those of the first embodiment, and a description thereof is omitted or simplified, and differences from the first embodiment will be mainly described.

Referring toFIG.27, the drive structure2400of the second embodiment includes a housing2111, a drive unit2150, and a wheel2120of a tire. The housing2111is an example of the support. The drive unit2150is supported by the housing2111. The drive unit2150includes a motor151, a speed reducer152, and a bearing153. The bearing153includes an outer ring1531and an inner ring1532. The motor151is provided on an input side of the speed reducer152, and the bearing153is provided on an output side of the speed reducer152. The motor151is a drive source of the wheel2120, and drives a wheel shaft2112via the speed reducer152.

The bearing153is disposed between the housing2111and the drive unit2150. As in the first embodiment described above, the output side of the speed reducer152of the drive unit2150and the wheel shaft2112are connected to the housing2111via the bearing153and a coupling member183. The wheel shaft2112functions as a positioning member that positions the bearing153and the speed reducer152with respect to the drive unit2150. In the second embodiment, the inner ring1532of the bearing153is disposed to face the drive unit2150, and the outer ring1531of the bearing153is disposed to face the housing2111.

The motor151, the speed reducer152, and the bearing153become frictional resistance when axes thereof are misaligned from each other. Therefore, in order to perform highly efficient driving, it is required to position the motor151, the speed reducer152, and the bearing153with high accuracy, that is, to align the axes of the motor151, the speed reducer152, and the bearing153with each other.

The housing2111has an opening portion through which cables pass and has a substantially U-shaped portion (seeFIG.28). The drive unit2150is disposed in the U-shaped portion. In the second embodiment, the drive unit2150is mounted on the U-shaped portion so as to be integrally detachable from the U-shaped portion of the housing2111. In other words, the drive unit2150is unitized, that is, integrated, and attached to the housing2111so as to be detachable from the housing2111in an integrated state.

Next, the method of assembling the drive structure2400according to the second embodiment will be described with reference toFIG.28. Similarly to the above-described first embodiment, the housing2111that is the support includes a base portion2113and a pair of support portions2114and2115spaced apart from the base portion2113. The support portions2114and2115are two portions that form a part of the U-shaped portion of the housing2111. The support potion2114includes an annular portion2116in which the drive unit2150is disposed. The support portion2115includes an annular portion2117in which the drive unit2150is disposed.

As illustrated inFIG.28, the drive unit2150is moved in a left direction inFIG.28to pass through an opening of the annular portion2116of the support potion2114, and the drive unit2150is disposed between the pair of support portions2114and2115. Then, a flange portion1613of a positioning member161is fixed to the annular portion2116formed by the support portion2114and the base portion2113by a fastening member (not illustrated). Further, the coupling member183is fitted to the outer ring1531of the bearing153of the drive unit2150, and the coupling member183is fixed to the annular portion2117formed by the support portion2115and the base portion2113by a fastening member182. At this time, the coupling member183and the outer ring1531of the bearing153are preferably fitted by transition fitting or interference fitting. The drive structure2400can be assembled by fixing the wheel2120to the wheel shaft2112by a fastening member184.

The coupling member183and the components inside the drive unit2150can be manufactured by a general-purpose machine similarly to of the robot of the first embodiment described above, and the motor151, the speed reducer152, and the bearing153can be assembled to each other with high assembly accuracy. Therefore, the drive unit2150can be assembled with high accuracy, and the drive unit2150can function as a drive device with compensated accuracy.

On the other hand, the pair of support portions2114and2115of the housing2111do not need to have a highly accurate positional relationship with each other as in the comparative example. That is, parallelism of the pair of support portions2114and2115and coaxiality and size tolerance (fitting tolerance) of the annular portions2116and2117in which the drive unit2150is disposed do not need to be as highly accurate as the drive unit2150. Since the accuracy of the drive device is compensated by the drive unit2150, the drive unit2150can be installed in the U-shaped portion of the housing2111to function as the drive device. A relative position error between the two support portions2114and2115is absorbed by an allowable inclination, an internal gap, or a fitting gap of the bearing153itself.

As described above, in the second embodiment, the motor151, the speed reducer152, and the bearing153can be axially aligned when the drive unit2150is assembled, and it is not necessary to perform axial alignment unlike the comparative example. Therefore, it is not necessary to increase the size and weight unlike the comparative example, the housing2111can be reduced in size and weight, and the motor151, the speed reducer152, and the bearing153can be axially aligned with high accuracy. Therefore, frictional resistance can be reduced. In the second embodiment, the housing2111is integrally molded. Therefore, it is possible to reduce the size and weight of the housing2111while securing stiffness necessary for the housing2111. Then, it is sufficient if the drive unit2150including the motor151, the speed reducer152, and the bearing153that are axially aligned is attached to the housing2111. As the motor151, the speed reducer152, and the bearing153are axially aligned, performance and durability of the motor151, the speed reducer152, and the bearing153can be improved. In addition, frictional resistance caused by axial misalignment of the motor151, the speed reducer152, and the bearing153can be reduced, and positioning control and speed control of two or more wheels provided in an automobile can be performed with high accuracy. That is, it is possible to perform a highly accurate and highly efficient driving operation.

Third Embodiment

Next, a third embodiment will be described in detail. In the second embodiment described above, a serial drive mechanism has been described as an example. The present disclosure is also applicable to a parallel drive mechanism. In the third embodiment, an electric vehicle will be described as an example.FIG.29is an explanatory view of a drive structure2500of an automobile according to the third embodiment, the drive structure2500including a motor and a wheel.FIG.30is an explanatory view of a method of assembling the drive structure2500of the automobile according to the third embodiment, the drive structure2500including the motor and the wheel. In the following, the same reference numerals will be used for the same or corresponding configurations as those of the first and second embodiments, and a description thereof is omitted or simplified, and differences from the first and second embodiments will be mainly described.

As illustrated inFIG.29, in the parallel drive structure2500of the third embodiment, a shaft2501of a motor151and a wheel shaft2502are not aligned with each other. In general, power of a motor is transmitted to a wheel via a speed reducer. As the speed reducer, a gear train, a belt, a chain, or the like is used. The drive structure2500of the third embodiment includes a housing2111, a drive unit2150, and a wheel (not illustrated). The housing2111is an example of the support. The drive unit2150is supported by the housing2111. The drive unit2150includes the motor151, a first speed reducer2152, and a bearing153. The motor151is provided on an input side of the first speed reducer2152, and the bearing153is provided on an output side of the first speed reducer2152. An input gear2154ais formed on an output shaft of the first speed reducer2152and is engaged with an output gear2154bprovided on the wheel to form a second speed reducer2154.

Referring toFIG.29, the motor151drives the wheel (tire) (not illustrated) via the first speed reducer2152and the second speed reducer2154. The bearing153is disposed between the housing2111and the drive unit2150. As in the second embodiment, an outer ring1531of the bearing153is connected to a coupling member183and is provided in the housing2111via the coupling member183. An inner ring1532of the bearing153is connected to the input gear2154athat receives an output from the first speed reducer2152. The motor151, the first speed reducer2152, and the bearing153become frictional resistance when axes thereof are misaligned from each other. Therefore, in order to perform highly efficient driving, it is required to position the motor151, the first speed reducer2152, and the bearing153with high accuracy, that is, to align the axes of the motor151, the first speed reducer2152, and the bearing153with each other.

The housing2111has an opening portion through which the second speed reducer2154passes, and has a substantially U-shaped portion (seeFIG.30). The drive unit2150is disposed in the U-shaped portion. In the third embodiment, the drive unit2150is mounted on the U-shaped portion so as to be integrally detachable from the U-shaped portion of the housing2111. In other words, the drive unit2150is unitized, that is, integrated, and attached to the housing2111so as to be detachable from the housing2111in an integrated state.

Next, the method of assembling the drive structure2500according to the third embodiment will be described with reference toFIG.30. Similarly to the above-described second embodiment, the housing2111that is the support includes a base portion2113and a pair of support portions2114and2115spaced apart from the base portion2113. The support portions2114and2115are two portions that form a part of the U-shaped portion of the housing2111. The support potion2114includes an annular portion2116in which the drive unit2150is disposed. The support portion2115includes an annular portion2117in which the drive unit2150is disposed.

As illustrated inFIG.30, the drive unit2150is moved in a left direction inFIG.30to pass through an opening of the annular portion2116of the support potion2114, and the drive unit2150is disposed between the pair of support portions2114and2115. Then, a flange portion1613of a positioning member161is fixed to the annular portion2116formed by the support portion2114and the base portion2113by a fastening member (not illustrated). Further, the coupling member183is fitted to the outer ring1531of the bearing153of the drive unit2150, and the coupling member183is fixed to the annular portion2117formed by the support portion2115and the base portion2113by a fastening member182. The input gear2154afunctions as a positioning member that positions the bearing153with respect to the drive unit2150. At this time, the coupling member183and the outer ring1531of the bearing153are preferably fitted by transition fitting or interference fitting. Then, the drive structure2500can be assembled by engaging the output gear2154bwith the input gear2154a.

The coupling member183and the components inside the drive unit2150can be manufactured by a general-purpose machine similarly to of the robot of the first embodiment described above, and the motor151, the first speed reducer2152, and the bearing153can be assembled to each other with high assembly accuracy. Therefore, the drive unit2150can be assembled with high accuracy, and the drive unit2150can function as a drive device with compensated accuracy.

On the other hand, the pair of support portions2114and2115of the housing2111do not need to have a highly accurate positional relationship with each other as in the comparative example. That is, parallelism of the pair of support portions2114and2115and coaxiality and size tolerance (fitting tolerance) of the annular portions2116and2117in which the drive unit2150is disposed do not need to be as highly accurate as the drive unit2150. Since the accuracy of the drive device is compensated by the drive unit2150, the drive unit2150can be installed in the U-shaped portion of the housing2111to function as the drive device. A relative position error between the two support portions2114and2115is absorbed by an allowable inclination, an internal gap, or a fitting gap of the bearing153itself.

As described above, in the third embodiment, the motor151, the first speed reducer2152, and the bearing153can be axially aligned when the drive unit2150is assembled, and it is not necessary to perform axial alignment unlike the comparative example. Therefore, it is not necessary to increase the size and weight unlike the comparative example, the housing2111can be reduced in size and weight, and the motor151, the speed reducer152, and the bearing153can be axially aligned with high accuracy. Therefore, frictional resistance can be reduced. In the third embodiment, the housing2111is integrally molded. Therefore, it is possible to reduce the size and weight of the housing2111while securing stiffness necessary for the housing2111. Then, it is sufficient if the drive unit2150including the motor151, the first speed reducer2152, and the bearing153that are axially aligned is attached to the housing2111. As the motor151, the first speed reducer2152, and the bearing153are axially aligned, performance and durability of the motor151, the first speed reducer2152, and the bearing153can be improved. In addition, frictional resistance caused by axial misalignment of the motor151, the first speed reducer2152, and the bearing153can be reduced, and positioning control and speed control of two or more wheels provided in an automobile can be performed with high accuracy. That is, it is possible to perform a highly accurate and highly efficient driving operation.

As described above, according to the present disclosure, it is possible to improve accuracy of the operation executed by the apparatus.

Other Modified Examples

Note that the present disclosure is not limited to the embodiments described above, and many modifications can be made within the technical idea of the present disclosure. For example, at least two of the above-described embodiments and the plurality of modified examples may be combined. In addition, the effects described in the present embodiment merely enumerate the most preferable effects that result from the embodiment of the present disclosure, and the effects of the embodiments of the present disclosure are not limited to those described in the present embodiment.

In the first embodiment described above, a mode in which the proximal end side link111is provided on a fixed side (input side) of the speed reducer and the distal end side link112is provided on a rotation side (output side) of the speed reducer has been described as an example. However, depending on how the speed reducer is fixed, a member on the output side of the speed reducer (for example, circular spline) may be fixed to the link111, and a member on the input side of the speed reducer (for example, flex spline) may be provided on a member that outputs rotation to form a joint. In this way, the link112can be provided on the fixed side (input side) of the speed reducer, and the link111can be provided on the rotation side (output side) of the speed reducer.

In the above-described first embodiment, a case where the robot is a vertical articulated robot has been described, but the present technology is not limited thereto. The robot may be, for example, a horizontal articulated robot, a parallel linked robot, or an orthogonal robot. The present disclosure can be applied to a machine capable of automatically performing an operation of expansion and contraction, bending and stretching, vertical movement, horizontal movement, or turning, or a combined operation thereof based on information of the storage device provided in the control device.

In the first embodiment and the plurality of modified examples described above, the joint J2among the plurality of joints has been described, but the present technology is not limited thereto. The joint structure of any one of the first embodiment and the plurality of modified examples described above may be applied to a joint other than the joint J2.

In the first embodiment and the plurality of modified examples described above, a case where the outer ring1531of the inner ring1532and the outer ring1531of the bearing153is supported by the positioning member162and the inner ring1532is supported by the support portion1112of the link111has been described. However, the present technology is not limited thereto, and although not illustrated, the inner ring1532of the inner ring1532and the outer ring1531of the bearing153may be supported by the positioning member162and the outer ring1531may be supported by the support portion1112of the link111. That is, one of the inner ring1532and the outer ring1531of the bearing153may be supported by the positioning member162, and the other may be supported by the support portion1112of the link111.

Other Embodiments

This application claims the benefit of Japanese Patent Application No. 2023-114780, filed Jul. 12, 2023, and Japanese Patent Application No. 2024-092622, filed Jun. 6, 2024, which are hereby incorporated by reference herein in their entirety.