Actuator and actuator unit

Abstract

This provides an actuator that allows for monitoring the rotational state of the output shaft while also offering advantages in miniaturizing the gearbox and motor. [Solution] An actuator comprising a motor 18 having a motor shaft 16, and a reduction gear 20 capable of outputting a rotation reduced from the rotation of the motor shaft 16 to a driven member 12 from an output shaft 44, further comprising a non-load side rotating body 22 positioned on the non-load side with respect to the motor shaft 16 and provided to be rotatable relative to the motor shaft 16, and a rotation detector for detecting the rotation of the non-load side rotating body 22, wherein the output shaft 44 and the non-load side rotating body 22 can each be connected to a driven member 12 positioned outside the actuator 10.

Description

Technical Field

[0001] The present disclosure relates to an actuator.

Background Art

[0002] Patent Document 1 discloses an actuator including a motor having a motor shaft and a speed reducer disposed on the load side with respect to the motor. This speed reducer includes an output shaft capable of outputting a rotation decelerated from the rotation of the motor shaft to a driven member. The actuator of Patent Document 1 includes a detection shaft that penetrates the speed reducer and the motor and is integrally rotatable with the output shaft, and a rotation detector that detects the rotation of the detection shaft, in order to grasp the rotation state of the output shaft.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventor of the present application has recognized that there is room for improvement in the disclosed technology of Patent Document 1 in order to advantageously miniaturize the speed reducer and the motor while being able to grasp the rotation state of the output shaft.

[0005] One object of the present disclosure is to provide an actuator that is advantageous for miniaturization of a speed reducer and a motor while being able to grasp the rotation state of an output shaft.

Means for Solving the Problems

[0006] The actuator of the present disclosure comprises a motor having a motor shaft, and a reduction gear capable of outputting a rotation reduced to the rotation of the motor shaft to a driven member from an output shaft, the actuator further comprising a non-load side rotating body disposed on the non-load side with respect to the motor shaft and provided to be rotatable relative to the motor shaft, and a rotation detector for detecting the rotation of the non-load side rotating body, wherein the output shaft and the non-load side rotating body are each connectable to the driven member disposed outside the actuator. [Effects of the Invention]

[0007] According to this disclosure, it is possible to control the rotational state of the output shaft while also making it advantageous to miniaturize the reducer and motor. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the actuator unit of the embodiment. [Figure 2] This is a side cross-sectional view showing the actuator unit of the embodiment. [Figure 3] This is a magnified view of a portion of Figure 1. [Modes for carrying out the invention]

[0009] Embodiments for carrying out the actuators of this disclosure are described below. Identical or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted. For the sake of clarity, components are omitted, enlarged, or reduced in each drawing as appropriate. The drawings should be viewed in accordance with the orientation of the reference numerals. In this specification, the notations "first" and "second" are used solely as formal designations to distinguish multiple elements and have no other substantive meaning. For example, a "second" element may exist without a "first" element.

[0010] Refer to Figure 1. The actuator 10 is incorporated into the master machine. The actuator 10 can drive the driven elements of the master machine by outputting rotation. The master machine is, for example, (1) robots such as industrial robots and service robots, (2) industrial machinery such as machine tools and construction machinery, (3) transportation equipment such as conveyors, and (4) various machines such as vehicles. Here, we will describe an example in which the master machine is a robot and the actuator 10 is incorporated into its joints. The actuator 10 is an integrated actuator in which a motor casing 32 and a reduction gear casing 42, which will be described later, are integrated.

[0011] The actuator 10 is used in combination with a driven member 12, which is part of the main machine. The actuator 10 and the driven member 12 constitute an actuator unit 14. The driven member 12 is connected to the output shaft 44 of a reduction gear 20, which will be described later, and is capable of transmitting the rotation output from the output shaft 44 to the driven element of the main machine.

[0012] Refer to Figure 2. In this figure, for some connectors such as bolts, only the axis passing through their shafts is shown as a dashed line. The actuator 10 includes a motor 18 having a motor shaft 16, a reduction gear 20 positioned on the load side of the motor 18, a non-load side rotating body 22 positioned on the non-load side of the motor shaft 16, a first rotation detector 24 for detecting the rotation of the motor shaft 16, and a second rotation detector 26 for detecting the rotation of the non-load side rotating body 22. In addition, the actuator 10 includes a casing body 28 including the motor casing 32 of the motor 18, and a non-load side bearing 30 that rotatably supports the non-load side rotating body 22 with respect to the casing body 28.

[0013] In this specification, the direction along the rotational centerline La of the motor shaft 16 is simply referred to as the axial direction, and the radial and circumferential directions of a circle with the rotational centerline La as its center are simply referred to as the radial direction and circumferential direction, respectively. Furthermore, the side in the axial direction from the motor 18 toward the reduction gear 20 (left side of Figure 2) is referred to as the load side, and the opposite side in the axial direction (right side of Figure 2) is referred to as the non-load side.

[0014] The motor 18 comprises a motor casing 32, a stator 34 fixed to the motor casing 32, and a rotor 36 rotatably mounted integrally with the motor shaft 16. The motor casing 32 houses the motor shaft 16, the stator 34, and the rotor 36. The type of rotor 36 is not particularly limited and may be a permanent magnet rotor, a squirrel-cage rotor, a wound-type rotor, a coreless rotor, etc. The type of stator 34 is not particularly limited and may be a permanent magnet stator, a wound-type stator, a coreless stator, etc.

[0015] The reduction gear 20 is capable of outputting a rotation reduced from the rotation of the motor shaft 16 to the driven member 12 via the output shaft 44. The reduction gear 20 comprises an input shaft 38 to which the rotation transmitted from the motor shaft 16 is input, a reduction mechanism 40 capable of reducing the rotation of the input shaft 38, a reduction gear casing 42 housing at least a part of the reduction mechanism 40, and an output shaft 44 positioned on the load side relative to the reduction mechanism 40. The reduction mechanism 40 in this embodiment comprises an external gear 46 and an internal gear 48 that mesh with each other. The reduction mechanism 40 in this embodiment is an eccentric oscillating type reduction mechanism that causes the external gear 46 to rotate by oscillating the external gear 46 with an eccentric body 50 provided on the input shaft 38, and transmits the rotation component to the output shaft 44.

[0016] In this embodiment, the input shaft 38 is provided so as to be rotatable integrally with the motor shaft 16. The input shaft 38 may be provided separately from the motor shaft 16, as in this embodiment, or it may be provided integrally with the motor shaft 16 using the same material.

[0017] The external gear 46 is provided in accordance with the eccentric body 50 and is supported by the corresponding eccentric body 50 via an eccentric bearing 52. The internal gear 48 is provided on the inner circumference of the reduction gear casing 42. A pin 54 protrudes from the output shaft 44 and passes through the external gear 46, and the rotational component of the external gear 46 is transmitted to the output shaft 44 by the pin 54.

[0018] The reduction gear casing 42 is disposed on the load side with respect to the motor casing 32. The reduction gear casing 42 houses, in addition to at least a part of the reduction mechanism 40 (here, the external gear 46), an input shaft 38, an output shaft 44, etc. The reduction gear casing 42 of the present embodiment is composed of a plurality (here, three) of reduction gear casing members 56 that are connected by a connector such as a bolt. A main bearing 58 that supports the output shaft 44 is disposed between the reduction gear casing 42 and the output shaft 44. The output shaft 44 of the present embodiment is composed of a plurality of output shaft members 60 that are connected by a connector B1 such as a bolt.

[0019] The actuator 10 may include a load-side hollow portion 62 that axially penetrates the reduction gear 20 and the motor shaft 16. The load-side hollow portion 62 of the present embodiment penetrates, in addition to the motor shaft 16, the output shaft 44 of the reduction gear 20 and the input shaft 38 of the reduction gear 20 integrated with the motor shaft 16.

[0020] The casing body 28 of the present embodiment includes, in addition to the motor casing 32, a reduction gear casing 42 and a counter-load-side casing 64 disposed on the counter-load side with respect to the motor casing 32. The casing body 28 is connected to a support member 66 disposed outside the actuator 10 and is supported by the support member 66.

[0021] Referring to FIG. 3. The counter-load-side casing 64 is connected to the motor casing 32 by a connector B2 such as a bolt. The counter-load-side casing 64 includes an outer peripheral wall portion 64a and an end wall portion 64b that protrudes radially inward from the counter-load-side end of the outer peripheral wall portion 64a.

[0022] The counter-load side casing 64 of this embodiment is composed of a plurality of counter-load side casing members 68A and 68B. The plurality of counter-load side casing members 68A and 68B include a first counter-load side casing member 68A disposed inside the motor casing 32 and a second counter-load side casing member 68B provided on the counter-load side with respect to the first counter-load side casing member 68A. The first counter-load side casing member 68A is connected to the motor casing 32 by a connector B2, and the second counter-load side casing member 68B is connected to the first counter-load side casing member 68A by a connector (not shown) such as a bolt.

[0023] The counter-load side rotating body 22 is provided so as to be relatively rotatable with respect to the motor shaft 16. The respective rotation center lines of the counter-load side rotating body 22 and the output shaft 44 are provided coaxially. The counter-load side rotating body 22 of this embodiment includes a first rotating member 70A and a second rotating member 70B connected to the first rotating member 70A by a connector B3 such as a bolt. This connector B3 jointly fastens the driven member 12 together with the first rotating member 70A and the second rotating member 70B. The first rotating member 70A is disposed on the counter-load side, and the second rotating member 70B is disposed on the load side rather than the first rotating member 70A. Each of the rotating members 70A and 70B has a shape obtained by axially dividing the counter-load side rotating body 22.

[0024] The counter-load side rotating body 22 may include a counter-load side hollow portion 72 penetrating the counter-load side rotating body 22 in the axial direction. The counter-load side hollow portion 72 of this embodiment is formed inside each of the rotating members 70A and 70B. In this embodiment, in the counter-load side hollow portion 72, the inner diameters of the respective rotating members 70A and 70B are different. The magnitude relationship of these inner diameters is not particularly limited and may be the same.

[0025] The non-load side bearing 30 comprises a plurality of rolling elements 30a and an outer ring 30b and an inner ring 30c on which the plurality of rolling elements 30a roll. In this embodiment, the non-load side bearing 30 is a ball bearing, but its type is not particularly limited, and it may be a roller bearing or the like. The outer ring 30b is arranged on the inner circumference of the casing body 28, and the inner ring 30c is arranged on the outer circumference of the non-load side rotating body 22. The non-load side bearing 30 is positioned between the casing body 28 and the non-load side rotating body 22. In this embodiment, the non-load side bearing 30 is positioned between the non-load side casing 64 and the non-load side rotating body 22, and rotatably supports the non-load side rotating body 22 with respect to the non-load side casing 64.

[0026] The first rotation detector 24 in this embodiment is a rotary encoder, but its specific example is not particularly limited and may be a resolver, potentiometer, etc. The first rotation detector 24 comprises a first detected part 24a provided on the motor shaft 16 and a first detection part 24b provided on the casing body 28. For example, the first detected part 24a is a ring member such as a code wheel or magnetic ring, and the first detection part 24b is a sensor such as an optical sensor or magnetic sensor. In this embodiment, the first detection part 24b is provided on the casing body 28 via a first circuit board 74 attached to the casing body 28. When the first detected part 24a rotates together with the motor shaft 16, the first detection part 24b detects the rotation of the motor shaft 16 by detecting a change in a predetermined physical quantity (magnetic field, light intensity, etc.) caused by the rotation of the first detected part 24a. The first detection part 24b works in cooperation with the first detected part 24a to detect the rotation of the motor shaft 16. In this context, "detecting rotation" means detecting information related to the rotation of the object being referred to. This rotational information includes, for example, the rotational position and rotational speed of the object being referred to.

[0027] The second rotation detector 26 in this embodiment is a rotary encoder, but its specific example is not particularly limited and may be a resolver, potentiometer, etc. The second rotation detector 26 comprises a second detected part 26a provided on the non-load side rotating body 22 and a second detection part 26b provided on the casing body 28. For example, the second detected part 26a is a ring member such as a code wheel or magnetic ring, and the second detection part 26b is a sensor such as an optical sensor or magnetic sensor. In this embodiment, the second detection part 26b is provided on the casing body 28 via a second circuit board 76 attached to the casing body 28. When the second detected part 26a rotates together with the non-load side rotating body 22, the second detection part 26b detects the rotation of the non-load side rotating body 22 by detecting a change in a predetermined physical quantity (magnetic field, light intensity, etc.) caused by the rotation of the second detected part 26a. The second detection unit 26b works in cooperation with the second detected unit 26a to detect the rotation of the non-load side rotating body 22.

[0028] The first detection unit 24b outputs a detection signal indicating the detected rotation of the motor shaft 16 to the motor driver (not shown). The second detection unit 26b outputs a detection signal indicating the detected rotation of the non-load side rotating body 22 to the motor driver. The motor driver controls the operation of the motor 18 based on the detection signals output from the first detection unit 24b and the second detection unit 26b. The motor driver may be located outside the actuator 10, or it may be mounted on either the first or second circuit board 74 or 76.

[0029] Refer to Figures 1 and 2. The driven member 12 is located outside the actuator 10. The driven member 12 does not axially penetrate the inside of the motor 18 and the reduction gear 20. It can also be said that the driven member 12 does not axially penetrate the inside of the load-side hollow portion 62 that penetrates the motor 18 and the reduction gear 20.

[0030] The driven member 12 includes a first connecting portion 12a connected to the output shaft 44 using a connector B1 such as a bolt, a second connecting portion 12b connected to the non-load side rotating body 22 using a connector B3 such as a bolt, and a connecting portion 12c connecting the first connecting portion 12a and the second connecting portion 12b. The output shaft 44 and the non-load side rotating body 22 can each be connected to the driven member 12. In this embodiment, the driven member 12 is U-shaped overall due to the first connecting portion 12a, the second connecting portion 12b, and the connecting portion 12c. A driven element (not shown) is connected to the driven member 12.

[0031] In this embodiment, the first connecting portion 12a is positioned on the load side with respect to the output shaft 44, and the second connecting portion 12b is positioned on the non-load side with respect to the non-load side rotating body 22. The connectors B1 and B3 used to connect the respective connecting portions 12a and 12b are arranged at intervals in the circumferential direction around the rotational centerline La of the motor shaft 16. In this embodiment, the connector B1 used to connect the first connecting portion 12a also fastens together with multiple output shaft members 60 in addition to the first connecting portion 12a.

[0032] The first connecting portion 12a is provided with a first through-hole 12d that penetrates the first connecting portion 12a in the axial direction. The first through-hole 12d is provided so as to surround the rotational centerline La of the motor shaft 16. If a wiring member is to be inserted inside the load-side hollow portion 62, the first through-hole 12d can allow the wiring member to pass through to the inside.

[0033] The second connecting portion 12b is provided with a second through-hole 12e that penetrates the second connecting portion 12b in the axial direction. A protrusion 22a provided on the non-load side rotating body 22 and projecting toward the non-load side may be fitted into the second through-hole 12e. The second through-hole 12e is provided so as to surround the rotation centerline La of the motor shaft 16. In order to satisfy this condition, the second through-hole 12e in this embodiment has a closed cross-sectional shape in a cross-section perpendicular to the axial direction, but may have an open cross-sectional shape that is open in a direction perpendicular to the axial direction.

[0034] The second through-hole 12e allows the wiring member 78 to pass through the inside of the non-load-side hollow portion 72 when the wiring member 78 is inserted inside the hollow portion 72. Here, only the center line of the wiring member 78 is shown by a dashed line. In this embodiment, the wiring member 78 is shown as being connected to the second circuit board 76, but it may also be connected to the first circuit board 74, or it may be inserted into the load-side hollow portion 62, etc., without being connected to these. This wiring member 78 may, for example, be a transmission path for electrical signals transmitted between circuit components mounted on the first and second circuit boards 74 and 76 and external electrical equipment. These circuit components refer to, for example, sensors that constitute the aforementioned detection units 24b and 26b. In addition, the wiring member 78 may also be a transmission path for electrical signals transmitted between multiple external electrical devices.

[0035] The connecting portion 12c is positioned outside the actuator 10, overlapping radially with the actuator 10. The connecting portion 12c may be provided in, for example, half or less of the circumferential range of the entire circumferential range around the rotational centerline La of the motor shaft 16, or in a circumferential range of one-quarter or less.

[0036] The minimum inner diameter L72 of the non-load side hollow section 72 may be larger than the minimum inner diameter L62 of the load side hollow section 62. The minimum inner diameter L72 of the non-load side hollow section 72 refers to the minimum value of the inner diameter of the non-load side hollow section 72. The minimum inner diameter L62 of the load side hollow section 62 refers to the minimum value of the inner diameter of the load side hollow section 62.

[0037] The effects of the actuator 10 described above will now be explained.

[0038] The output shaft 44 and the non-load side rotating body 22 can each be connected to a driven member 12 located outside the actuator 10. By connecting them to the driven member 12, the non-load side rotating body 22 can be rotated at the same rotational speed as the output shaft 44. By detecting the rotation of the non-load side rotating body 22 with the second rotation detector 26, the rotational state of the output shaft 44 can be determined. For example, by detecting the rotational position, rotational speed, etc. of the non-load side rotating body 22 with the second rotation detector 26, the rotational position, rotational speed, etc. of the output shaft 44, which rotates at the same rotational speed as the non-load side rotating body 22, can be determined.

[0039] Furthermore, in order to grasp the rotational state of the output shaft 44 in this way, it is sufficient to connect the output shaft 44 and the non-load side rotating body 22 to the driven member 12 located outside the actuator 10. Therefore, in order to grasp the rotational state of the output shaft 44, it is not necessary to provide a detection shaft that passes through the reduction gear 20 and motor 18 and rotates integrally with the output shaft 44. Consequently, it is not necessary to secure space for the detection shaft inside the reduction gear 20 and motor 18, which is advantageous for miniaturizing the reduction gear 20 and motor 18. By making the reduction gear 20 and motor 18 more compact, it is also advantageous when selecting a reduction gear 20 and motor 18 of a suitable size from off-the-shelf products.

[0040] In particular, since it is not necessary to provide a detection shaft within the load-side hollow section 62 that passes through the input shaft 38 and motor shaft 16 of the reduction gear 20, it is advantageous in terms of increasing the internal space of the load-side hollow section 62. Furthermore, if it is not necessary to increase the internal space of the load-side hollow section 62, it is advantageous for miniaturizing the input shaft 38 and motor shaft 16, and also for miniaturizing the first rotation detector 24, which is partially provided on the motor shaft 16. In addition, wiring members can be directly inserted into the load-side hollow section 62 that passes through the input shaft 38 and motor shaft 16. Therefore, compared to the case where a hollow section for wiring members is provided on the detection shaft, there is also the advantage of avoiding the need to reduce the inner diameter of the hollow section through which the wiring members are directly inserted.

[0041] Let's consider the case where the components of the second rotation detector 26 are placed outside the actuator 10. In this case, the actuator alone does not fully perform the function of the second rotation detector 26, which poses a problem in terms of convenience for users who utilize the actuator 10 provided by the actuator provider (e.g., the manufacturer). For example, it is inconvenient for the designer of the master machine into which the actuator will be incorporated, as it requires a dedicated design for the second rotation detector 26. Also, it is inconvenient for the assembler of the master machine, as it requires the extra step of incorporating the components of the second rotation detector 26 separately from the actuator 10 when incorporating the actuator 10 into the master machine.

[0042] In this respect, according to this embodiment, the actuator 10 itself is equipped with the second rotation detector 26, and the function of the second rotation detector 26 is completed within the actuator alone. Therefore, it is convenient for users who use the actuator. For example, it is convenient for the designer of the main machine because it eliminates the need for a dedicated design for the second rotation detector 26. Also, it is convenient for the assembler of the main machine because it eliminates the need to assemble the components of the second rotation detector 26 when incorporating the actuator 10 into the main machine.

[0043] The fact that the actuator 10 alone completes the function of the second rotation detector 26 means that it is not necessary to provide the components of the second rotation detector 26 separately from the actuator 10 as part of the main machine. The components of the second rotation detector 26 here refer to the second detected part 26a and the second detection part 26b of the second rotation detector 26. Since the second detected part 26a is provided on the non-load side rotating body 22 and the second detection part 26b is provided on the casing body 28, the actuator 10 alone completes the function of the second rotation detector 26, which can be seen as superior in terms of user convenience.

[0044] Since there is no reduction gear 20 around the non-load side rotating body 22, and most of the components of the motor 18 (stator 34, rotor 36, motor shaft 16, etc.) are absent, the design is less constrained by these. Therefore, it is advantageous to increase the inner diameter of the non-load side hollow portion 72 of the non-load side rotating body 22. In addition, increasing the inner diameter of the non-load side hollow portion 72 of the non-load side rotating body 22 is advantageous for directly inserting the wiring member 78. Furthermore, even if the inner diameter of the load side hollow portion 62 that passes through the reduction gear 20 and motor shaft 16 is small, or if the load side hollow portion 62 does not exist, the non-load side hollow portion 72 of the non-load side rotating body 22 can be effectively used as a passage for the wiring member 78. From this viewpoint, the minimum inner diameter L72 of the non-load side hollow portion 72 may be larger than the minimum inner diameter L62 of the load side hollow portion 62.

[0045] The second connecting portion 12b of the driven member 12 is provided with a second through hole 12e. Therefore, when inserting the wiring member 78 into the non-load side hollow portion 72 of the non-load side rotating body 22, interference between the wiring member 78 and the driven member 12 can be avoided by arranging the wiring member 78 so that it passes inside the second through hole 12e. In addition, since there is space to arrange the connector B3 around the second through hole 12e, it is advantageous to increase the number of connectors B3.

[0046] Next, other features of the actuator 10 will be described. Refer to Figure 3. The second rotation detector 26 may be housed inside the casing body 28. In this embodiment, the second rotation detector 26 is housed inside the non-load side casing 64 of the casing body 28. In this embodiment, the second rotation detector 26 is housed in a location surrounded by the outer peripheral wall 64a on the load side of the end wall 64b of the non-load side casing 64. In this embodiment, the second rotation detector 26 is housed inside the casing body 28 on the non-load side of the motor shaft 16 and the first rotation detector 24. By housing the second rotation detector 26 inside the casing body 28, the influence of the external environment such as water, oil, and dust on the second rotation detector 26 can be suppressed, which is advantageous in maintaining the function of the second rotation detector 26.

[0047] In this embodiment, the outer ring 30b of the non-load-side bearing 30 is positioned on the inner circumference of the end wall portion 64b of the non-load-side casing 64. The actuator 10 includes a positioning member 80 connected to the casing body 28 by a connector B5 such as a bolt. In this embodiment, the positioning member 80 is positioned on the load side relative to the end wall portion 64b of the non-load-side casing 64.

[0048] The outer ring 30b may be positioned axially by the casing body 28 and the positioning member 80. To achieve this, the casing body 28 is provided with an outer ring movement restricting portion 82 that restricts the axial movement of the outer ring 30b by contacting the outer ring 30b from the axial side opposite to the positioning member 80. In this embodiment, the outer ring movement restricting portion 82 is formed by a stepped portion provided on the end wall portion 64b of the non-load side casing 64. The axial movement of the outer ring 30b is restricted by the outer ring movement restricting portion 82 of the casing body 28 and the positioning member 80, thereby positioning its relative position in the axial direction with respect to the casing body 28. As a result, the outer ring 30b can be positioned more firmly by the positioning member 80 connected to the casing body 28 compared to when the outer ring 30b is positioned by a retaining ring.

[0049] The inner ring 30c of the non-load-side bearing 30 may be positioned axially by a first rotating member 70A and a second rotating member 70B. To achieve this, the first rotating member 70A includes a first movement restricting portion 70Aa that restricts the axial movement of the inner ring 30c toward the non-load side by contacting the inner ring 30c from the non-load side. In this embodiment, the first movement restricting portion 70Aa is arranged on the outer circumference of the second rotating member 70B and is composed of a spigot fitting portion that engages with the second rotating member 70B in a spigot fitting. The second rotating member 70B includes a second movement restricting portion 70Ba that restricts the axial movement of the inner ring 30c toward the load side by contacting the inner ring 30c from the load side. In this embodiment, the second movement restricting portion 70Ba is composed of a stepped portion provided on the outer circumference of the second rotating member 70B. Specific examples of the first movement restricting portion 70Aa and the second movement restricting portion 70Ba are not particularly limited. For example, the first movement restricting portion 70Aa may be a stepped portion provided on the outer circumference of the first rotating member 70A, and the second movement restricting portion 70Ba may be an interlocking portion arranged on the outer circumference side of the first rotating member 70A and interlocking with the first rotating member 70A.

[0050] The inner ring 30c is positioned relative to the non-loaded rotating body 22 in the axial direction by the axial movement restriction of the first movement restricting portion 70Aa of the first rotating member 70A and the second movement restricting portion 70Ba of the second rotating member 70B. As a result, the inner ring 30c can be positioned more securely by the first rotating member 70A and the second rotating member 70B, which are connected to each other, compared to when the inner ring 30c is positioned using a retaining ring.

[0051] Next, we will explain the transformation forms of each component described so far.

[0052] The specific examples of the reduction mechanism 40 of the reducer 20 are not particularly limited. In addition to the eccentric oscillating reduction mechanism, the reduction mechanism 40 may also be a simple planetary gear reduction mechanism, a flexible meshing reduction mechanism (including cylindrical, top hat, and cup types), a right-angle gear reduction mechanism, a parallel-axis gear reduction mechanism, or other gear mechanisms. In addition to a gear mechanism, the reduction mechanism 40 may also be a friction transmission mechanism, etc. As an example of an eccentric oscillating reduction mechanism, a center crank type in which the input shaft 38 is positioned on the rotation centerline La has been described, but a distribution type in which the input shaft 38 is positioned radially offset from the rotation centerline La is also acceptable.

[0053] The casing body 28 does not necessarily have to include the non-load side casing 64. In this case, the non-load side rotating body 22 may be rotatably supported by the motor casing 32 by the non-load side bearing 30. The second rotation detector 26 may be located outside the casing body 28.

[0054] The non-load side rotating body 22 may be composed of a single member without the first and second rotating members 70A and 70B. The non-load side rotating body 22 may not have the non-load side hollow portion 72.

[0055] The outer ring 30b of the non-load-side bearing 30 may be positioned axially by a retaining ring or the like attached to the casing body 28. The inner ring 30c of the non-load-side bearing 30 may be positioned axially by a retaining ring or the like attached to the non-load-side rotating body 22.

[0056] The actuator 10 does not necessarily have a load-side hollow portion 62 that passes through the reduction gear 20 and the motor shaft 16. The minimum inner diameter L72 of the non-load-side hollow portion 72 may be less than or equal to the minimum inner diameter L62 of the load-side hollow portion 62.

[0057] The contents of each component described in the embodiments above are illustrative. The abstract technical ideas derived from these should not be interpreted restrictively to the contents of this specification. Many design changes, such as modifications, additions, and deletions, are possible for the contents of each component described in the embodiments. Such modifications are emphasized with the notations "this form" and "embodiment." However, design changes are also permitted for contents without such notations. Any combination of the above components is also valid. For example, any explanatory items of a modified form may be combined with an embodiment. The hatching applied to the cross-section in the drawings does not limit the material of the object to which the hatching is applied. The structures and numerical values ​​mentioned in the embodiments and modified forms naturally include those that can be considered identical when considering manufacturing tolerances, etc. Components composed of a single member in the description in this specification may be composed of multiple members. Similarly, components composed of multiple members may be composed of a single member. [Explanation of Symbols]

[0058] 10...Actuator, 12...Driven member, 12a...Connecting part, 14...Actuator unit, 16...Motor shaft, 18...Motor, 20...Gear reducer, 22...Non-load side rotating body, 26...Rotation detector (second rotation detector), 26a...Detected part (second detected part), 26b...Detection part (second detection part), 28...Casing body, 30...Non-load side bearing, 30b...Outer ring, 30c...Inner ring, 32...Motor casing, 44...Output shaft, 62...Load side hollow part, 64...Non-load side casing, 70A...First rotating member, 70B...Second rotating member, 72...Non-load side hollow part, 80...Positioning member.

Claims

1. A motor having a motor shaft, An actuator comprising a reduction gear capable of outputting a rotation reduced to the rotation of the motor shaft from the output shaft to a driven member, wherein A non-load side rotating body is positioned on the non-load side with respect to the motor shaft and is provided to be rotatable relative to the motor shaft, The system includes a rotation detector for detecting the rotation of the non-loaded rotating body, The output shaft and the non-load side rotating body are each connectable to the driven member located outside the actuator.

2. A casing body having the motor casing of the motor, The actuator according to claim 1, further comprising a non-load side bearing that rotatably supports the non-load side rotating body with respect to the casing body.

3. The actuator according to claim 2, wherein the rotation detector is housed inside the casing.

4. The actuator according to claim 2, wherein the rotation detector comprises a detection unit provided on the non-load side rotating body and a detection unit provided on the casing body that cooperates with the detection unit to detect the rotation of the non-load side rotating body.

5. It includes a positioning member that is connected to the casing body by a connector, The actuator according to claim 2, wherein the outer ring of the non-load-side bearing is positioned axially by the positioning member and the casing body.

6. The non-load side rotating body comprises a first rotating member and a second rotating member connected to the first rotating member by a connector. The actuator according to claim 2, wherein the inner ring of the non-load-side bearing is positioned axially by the first rotating member and the second rotating member.

7. The casing body comprises a non-load side casing positioned on the non-load side relative to the motor casing, The actuator according to claim 2, wherein the non-load-side bearing rotatably supports the non-load-side rotating body with respect to the non-load-side casing.

8. The actuator according to claim 1, wherein the non-load side rotating body is provided with a non-load side hollow portion that penetrates the non-load side rotating body in the axial direction.

9. The load-side hollow portion is provided, which penetrates the reduction gear and the motor shaft in the axial direction. The actuator according to claim 8, wherein the minimum inner diameter of the non-load side hollow portion is greater than the minimum inner diameter of the load side hollow portion.

10. An actuator according to any one of claims 1 to 9, An actuator unit comprising a driven member connected to the output shaft and the non-load side rotating body, respectively.

11. The driven member includes a connecting portion that is connected to the non-loaded rotating body, The non-load side rotating body is provided with a non-load side hollow portion that penetrates the non-load side rotating body in the axial direction, The actuator unit according to claim 10, wherein the connecting portion has a through hole through which a wiring member inserted into the non-load side hollow portion can pass inward.

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