Eccentric oscillation type speed reduction device, detection system, and control system

Abstract

To provide an eccentric oscillation type speed reduction device that can accurately detect a torque load in consideration of a problem of a conventional eccentric oscillation type speed reduction device.SOLUTION: An eccentric oscillation type speed reduction device 100 according to an embodiment comprises a shaft, eccentric parts 24 and 25 made eccentric by a predetermined amount with respect to the shaft, external gears 14 and 15 to be oscillated by the eccentric parts 24 and 25, and an internal gear 16 engaged with the external gears 14 and 15. The external gears 14 and 15 are provided with torque information detection means 5 for detecting information related to torque.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an eccentric swing type reduction gear, a detection system, and a control system.

Background Art

[0002] A load detection system for detecting a load applied to an eccentric swing type reduction gear is known. For example, Patent Document 1 describes a technique for calculating a load applied to a reduction gear based on the output of a strain gauge attached to a support body for an eccentric swing type reduction gear having a case with an internal gear on its inner circumference, a support body rotatably supported by the case via a main bearing, an external gear meshing with the internal gear, and a crankshaft for eccentrically rotating the external gear.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventor has obtained the following new recognition regarding an eccentric swing type reduction gear. It is conceivable to attach a strain gauge to a support body and detect a torque load applied to the eccentric swing type reduction gear from a detection signal of the strain gauge. However, the system described in Patent Document 1 has a structure in which a moment load applied to the device is received by a main bearing, and the support body supported by the main bearing is also affected by the moment load. Therefore, it is difficult to completely eliminate the influence of the moment load from the detection signal of the strain gauge. From these, there is room for improvement in the conventional system from the viewpoint of accurately detecting a torque load.

[0005] The present invention has been made in view of such problems, and one of its objects is to provide an eccentric swing type reduction gear capable of accurately detecting a torque load.

Means for Solving the Problems

[0006] In order to solve the above problems, an eccentric swing type reduction gear according to an aspect of the present invention includes a shaft, an eccentric portion that is eccentric from the shaft by a predetermined amount, an external gear that swings by the eccentric portion, and an internal gear that meshes with the external gear. Torque information detection means for detecting information regarding torque is provided on the external gear.

[0007] Another aspect of the present invention is a detection system. This detection system is a detection system for the above eccentric swing type reduction gear, and detects an abnormality of the eccentric swing type reduction gear based on a detection value detected by the torque information detection means.

[0008] Still another aspect of the present invention is a control system. This control system includes the above eccentric swing type reduction gear and an electric motor that inputs rotation to the shaft of the eccentric swing type reduction gear, and controls the electric motor using a detection value detected by the torque information detection means.

[0009] In addition, any combination of the above components, or those obtained by mutually replacing the components and expressions of the present invention among methods, systems, etc. are also effective as aspects of the present invention.

Effects of the Invention

[0010] According to the present invention, it is possible to provide an eccentric swing type reduction gear capable of accurately detecting a torque load.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described with reference to the drawings based on preferred embodiments. In the embodiments and modification examples, the same or equivalent components and members are denoted by the same reference numerals, and redundant explanations are omitted as appropriate. Also, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. In addition, a part of the members that are not important in explaining the embodiments in each drawing is omitted and shown.

[0013] Also, terms including ordinal numbers such as first and second are used to describe various components, but this term is used only for the purpose of distinguishing one component from another, and the components are not limited by this term.

[0014] [First Embodiment] With reference to FIGS. 1 and 2, the configuration of an eccentric swing type speed reduction device 100 (hereinafter sometimes simply referred to as "speed reduction device 100") according to the first embodiment will be described. FIG. 1 is a cross-sectional side view showing the speed reduction device 100. FIG. 2 is a front view showing the external gears 14 and 15 as viewed from the input side. The speed reduction device 100 of the embodiment is an eccentric swing type speed reduction device that causes one of the internal gear and the external gear to rotate by swinging the external gear that meshes with the internal gear, and outputs the generated rotation component from the output member to the driven member.

[0015] In the example of FIG. 1, the speed reduction device 100 is a so-called distribution type eccentric swing type speed reduction device in which the crankshaft is arranged at a position offset from the axis of the internal gear. The speed reduction device 100 mainly includes torque information detection means 5, a crankshaft 20, external gears 14 and 15, an internal gear 16, carriers 35 and 36, a casing 60, main bearings 26 and 27, crankshaft bearings 39 and 40, and an input gear 23.

[0016] Hereinafter, the direction along the central axis line La of the internal gear 16 is referred to as the "axial direction", and the circumferential direction and the radial direction of the circle centered on the central axis line La are referred to as the "circumferential direction" and the "radial direction", respectively. Also, hereinafter, for convenience, one side in the axial direction (the right side in the figure) is referred to as the input side, and the other side (the left side in the figure) is referred to as the anti-input side.

[0017] In this specification, the load applied to the speed reducer 100 in the rotational direction centered on the central axis line La is referred to as the "torque load", and the load applied to the speed reducer 100 in the rotational direction centered on the axis orthogonal to the central axis line La is referred to as the "moment load".

[0018] The carriers 35 and 36 include a first carrier 35 disposed on the anti-input side portions of the external gears 14 and 15, and a second carrier 36 disposed on the input side portions of the external gears 14 and 15. The carriers 35 and 36 are rotatably supported by the casing 60 via the main bearings 26 and 27. The external gears 14 and 15 include a first external gear 14 disposed on the input side portion of the first carrier 35, and a second external gear 15 disposed on the anti-input side portion of the second carrier 36.

[0019] The main bearings 26 and 27 are disposed between the carriers 35 and 36 and the casing 60, and rotatably support the carriers 35 and 36 with respect to the casing 60. The main bearings 26 and 27 in this example are angular roller bearings, but are not limited thereto.

[0020] The casing 60 has a cylindrical shape surrounding the speed reducer 100, and the internal gear 16 is provided on the inner peripheral surface. The crankshaft bearings 39 and 40 are disposed between the crankshaft 20 and the carriers 35 and 36, and rotatably support the crankshaft 20 with respect to the carriers 35 and 36. The crankshaft bearings 39 and 40 in this example are spherical bearings, but are not limited thereto.

[0021] The crankshaft 20 exemplifies the shaft of the claims. Three crankshafts 20 are arranged at positions offset from the central axis La of the internal gear 16. The rotation center line of the crankshaft 20 is denoted by reference symbol Lb. The three crankshafts 20 are arranged at equal intervals in the circumferential direction. Only one crankshaft 20 is shown in FIG. 1. The crankshaft 20 has a plurality of eccentric portions 24, 25 that are eccentric by a predetermined amount with respect to the rotation center line Lb of the crankshaft 20 in order to swing the external gears 14, 15. The crankshaft 20 in this example has two eccentric portions 24, 25 whose eccentric phases are shifted from each other by 180°. The eccentric portions 24, 25 have an eccentric amount capable of realizing the deceleration operation described later.

[0022] The crankshaft 20 is rotatably supported by carriers 35, 36 via crankshaft bearings 39, 40. The crankshaft bearings 39, 40 are arranged between the crankshaft 20 and the carriers 35, 36 on the side portions of the external gears 14, 15.

[0023] The input gear 23 is provided at the input side end of each crankshaft 20. Only one input gear 23 is shown in FIG. 1. The input gear 23 transmits the rotation from the output shaft (not shown) of the electric motor to the crankshaft 20.

[0024] Referring to FIGS. 1 and 2, the external gears 14, 15 will be described. The external gears 14, 15 are provided corresponding to the eccentric portions 24, 25 via eccentric bearings 19 which are roller bearings, and swing by the eccentric portions 24, 25.

[0025] The external gears 14, 15 are provided with through holes 4 penetrating in the axial direction. The through holes 4 include a plurality of first offset holes 41, 42, a plurality of second offset holes 45, 46, and a center hole 47. The center hole 47 is arranged at the center of the external gears 14, 15.

[0026] The first offset holes 41 and 42 are each arranged in three equidistant positions in the circumferential direction. The second offset holes 45 and 46 are each arranged in three equidistant positions in the circumferential direction. The three first offset holes 41 are each provided between a plurality of second offset holes 45 in the circumferential direction. The three first offset holes 42 are each provided between a plurality of second offset holes 46 in the circumferential direction.

[0027] A swing pin 48 is inserted through the first offset holes 41 and 42. A crankshaft 20 provided with eccentric portions 24 and 25 is inserted into the second offset holes 45 and 46, respectively. A plurality of eccentric bearings 19 are interposed between the second offset holes 45 and 46 and the eccentric portions 24 and 25. The outer teeth formed on the outer circumferences of the external gears 14 and 15 are configured to be swingable by moving while contacting the internal gear 16.

[0028] The internal gear 16 has an internal gear main body 18 integrated with the inner circumferential portion of the casing 60 and an outer pin 17 disposed in a pin groove formed in the internal gear main body 18. The outer pin 17 constitutes the internal teeth of the internal gear 16 and meshes with the outer teeth of the external gears 14 and 15. The number of outer pins 17 is slightly (by 1 in this example) more than the number of outer teeth of the external gears 14 and 15.

[0029] The swing pin 48 extends axially from the first carrier 35 and is fixed to the second carrier 36 by a bolt B1. The swing pin 48 is inserted through the first offset holes 41 and 42 of the external gears 14 and 15 with a clearance.

[0030] One of the first carrier 35 and the casing 60 serves as an output member that outputs rotational power to the driven member 52, and the other serves as a fixed member that is fixed to an external member (not shown) for supporting the speed reduction device 100.

[0031] Next, the torque information detection means 5 will be described. From the viewpoint of accurately detecting the torque load by the torque information detection means, it is important to attach the torque information detection means to a part that is less affected by the moment load. In a speed reducer having a structure in which the moment load is received by the main bearing, the support body supported by the main bearing is affected by the moment load. Therefore, when the torque information detection means is attached to the support body, it is difficult to completely eliminate the influence of the moment load from the detection signal of the torque information detection means. From these, the inventors conceived of providing the torque information detection means 5 on the external gears 14 and 15. As a result of the study, the external gears 14 and 15 directly receive the torque load and are less affected by the moment load. Therefore, it was found that the torque load can be accurately detected by providing the torque information detection means 5 on the external gears 14 and 15.

[0032] The torque information detection means 5 only needs to be able to detect information related to torque, and the type is not limited. The torque information detection means 5 of the embodiment detects the strain of the detected portions of the external gears 14 and 15 and outputs a detection signal corresponding to the magnitude of the strain to the lead wires 58 and 59. The torque information detection means 5 of the embodiment is a strain gauge, but is not limited thereto, and any means that can detect the amount of deformation in which the detected portion expands and contracts slightly due to stress as an electric signal may be used.

[0033] The torque information detection means 5 can be attached to each part of the external gear 14, 15. Examples of the attachable parts include the tooth surface of the external gear (for example, a part that does not come into contact during tooth surface engagement), the axial end face of the external gear (for example, between a plurality of offset holes on the end face, particularly between the first offset hole and the second offset hole), the inner circumference of various holes, and the like. The torque information detection means 5 of the embodiment is attached to the inner circumference of the through hole 4. In this case, the sensitivity to the torque load is increased, and it is less affected by disturbances such as moment loads. The torque information detection means 5 may be attached to the second offset holes 45, 46, the center hole 47, or other through holes 4. In the embodiment, the torque information detection means 5 is attached to the first offset holes 41, 42. In this case, since the first offset holes 41, 42 have a wide area where the sensor can be attached, the torque information detection means 5 can be easily attached without contacting other members.

[0034] For example, two lead wires are connected to each torque information detection means 5. In FIG. 2, one of the two lead wires is shown. Reference numeral 58 indicates 12 lead wires from the six torque information detection means 5 provided on the external gear 14. Reference numeral 59 indicates 12 lead wires from the six torque information detection means 5 provided on the external gear 15. In FIG. 1, the lead wires 58, 59 are shown by a single line.

[0035] As shown in FIGS. 1 and 2, the external gears 14, 15 have a center hole 47, and the lead wires 58, 59 of the torque information detection means 5 extend axially outward from the center hole 47 of the reduction gear 100. In this case, since the wiring space is wide, even if the lead wires 58, 59 are bent, the lead wires 58, 59 are less likely to be entangled with each other, which is advantageous in terms of manufacturing cost compared to the case where a separate hole for the lead wire is provided.

[0036] The lead wires 58 and 59 are drawn out to the anti-input side through the central hole 47 and accommodated in the groove 38 formed on the side surface of the anti-input side of the first carrier 35. The groove 38 extends from the radially inner side to the outer side, and the anti-input side of the groove 38 is covered by the driven member 52. The lead wires 58 and 59 extend radially outward through the groove 38 and are drawn out to the outside of the first carrier 35.

[0037] As shown in FIG. 2, the torque information detection means 5 is attached to the P surface and the Q surface, which are the circumferential surfaces on both sides in the circumferential direction when the first offset holes 41 and 42 are bisected in the circumferential direction. In each of the first offset holes 41 and 42, the P surface and the Q surface face each other in the circumferential direction. The reference numeral 5P indicates the torque information detection means 5 attached to the P surface, and the reference numeral 5Q indicates the torque information detection means 5 attached to the Q surface. Each torque information detection means 5P outputs an electrical detection value Sp having a value substantially proportional to the magnitude of the strain generated on the P surface. Each torque information detection means 5Q outputs an electrical detection value Sq having a value substantially proportional to the magnitude of the strain generated on the Q surface. The electrical detection values include voltage values, current values, resistance values, and the like.

[0038] As a result of the inventors' study, it has been found that in the first offset holes 41 and 42, the P surface generates a larger strain than the Q surface when the external gear 14 and 15 receive a CW-direction torque load from the eccentric shaft, and the Q surface generates a larger strain than the P surface when the external gear 14 and 15 receive a CCW-direction torque load from the eccentric shaft.

[0039] Therefore, from the viewpoint of reducing the influence of disturbances, when receiving a CW-direction torque load, the strain G1, which is the magnitude of the strain, may be estimated using the average value Spa of the electrical detection values Sp of the six torque information detection means 5P attached to the P surface. Similarly, when receiving a CCW-direction torque load, the strain G1 may be estimated using the average value Sqa of the electrical detection values Sq of the six torque information detection means 5Q attached to the Q surface.

[0040] As a result of the inventors' studies, it has been found that even when the load torque is constant, the strain value varies periodically depending on the change in the meshing position. Based on this finding, it has been determined that the influence of the variation in the strain value due to the change in the meshing position can be canceled by using the average value of the strain at three points. Therefore, by using the average value Spa or the average value Sqa, it is possible to separate the variation in the strain value due to the change in the load torque from the variation in the strain value due to the change in the meshing position, and it is possible to accurately detect only the change in the load torque.

[0041] The strain G1 can be estimated by multiplying the average value Spa or the average value Sqa by a proportionality constant specified in advance by experiments or simulations. When using one of the electrical detection values Sp and Sq according to the rotation direction, the change in the value (strain) with respect to the torque load is larger according to the rotation direction than when using both together regardless of the rotation direction. Therefore, it is possible to use one of the detection values Sp and Sq where the change in the value is large, and it is not necessary to use the other detection value where the change in the value is small, which is advantageous in terms of accuracy.

[0042] With reference to FIG. 3, an example of the relationship between the strain G1 and the torque load T1 will be described. FIG. 3 shows an example of the relationship between the strain G1 and the torque load T1 detected by the speed reducer 100 in this example. In this figure, the horizontal axis represents the strain G1 estimated from the detection result of the torque information detection means 5. The strain is a dimensionless number without a unit name. In this figure, the vertical axis represents the torque load T1 of the speed reducer 100 obtained using a torque measuring instrument capable of directly measuring the torque load. In the speed reducer 100, as shown in FIG. 3, it has been found that the torque load T1 in the normal use range changes linearly with respect to the strain G1 and has the correlation shown by the formula (1). Torque load T1 = 10 × Strain G1 ···(1)

[0043] Note that the functional expression representing the correlation between the torque load T1 and the strain G1 can be calculated by the experiment of the following procedure. (1) Load a known torque load on the speed reducer and measure the strain value at that time. (2) Calculate the three-point average of the measured strain values. (3) As shown in FIG. 3, plot the three-point average of the calculated strain values and the torque load on a graph. (4) Vary the torque load and repeat steps (1) to (3). (5) Calculate a function formula representing the correlation as a regression line from the plotted points by the least squares method.

[0044] Note that the relationship between the strain G1 and the torque load T1 in FIG. 3 is just an example and varies depending on the configuration of the speed reducer. Therefore, it may be obtained for each speed reducer. Thus, according to the speed reducer 100, the torque load can be accurately specified from the detection result of the torque information detection means 5 of the speed reducer 100 without using a torque measuring instrument.

[0045] Referring to FIG. 1, the speed reduction operation of the speed reducer 100 will be described. The rotational power transmitted from the output shaft of the electric motor is distributed to the input gears 23, and the three input gears 23 rotate in the same phase. When the three input gears 23 rotate, the eccentric portions 24, 25 of the crankshaft 20 rotate around the rotation center line Lb passing through the crankshaft 20, and the external gear teeth 14, 15 swing due to the eccentric portions 24, 25. When the external gear teeth 14, 15 swing, the meshing positions of the external pins 17 of the external gear teeth 14, 15 and the internal gear 16 shift sequentially. As a result, every time the crankshaft 20 makes one rotation, rotation of either the external gear teeth 14, 15 or the internal gear 16 occurs by an amount corresponding to the difference between the number of teeth of the external gear teeth 14, 15 and the number of external pins 17 of the internal gear 16. When the external gear teeth 14, 15 rotate, a reduced-speed rotation is output from the first carrier 35 that rotates synchronously with the rotation component of the external gear teeth 14, 15, and the driven member 52 connected to the first carrier 35 is rotationally driven. When the internal gear 16 rotates, a reduced-speed rotation is output from the casing 60 that rotates integrally with the internal gear 16, and a driven member (not shown) connected to the casing 60 is rotationally driven.

[0046] The features of the eccentric swing type reduction gear 100 configured as described above will be described. The eccentric swing type reduction gear 100 has eccentric portions 24 and 25 that are eccentric by a predetermined amount, external gear wheels 14 and 15 that swing due to the eccentric portions 24 and 25, and an internal gear wheel 16 that meshes with the external gear wheels 14 and 15, and torque information detection means 5 for detecting distortion in the external gear wheels 14 and 15 is provided.

[0047] According to this configuration, since the torque information detection means 5 is provided in the external gear wheels 14 and 15 that are less affected by the moment load, it is possible to specify the torque load with the influence of the moment load reduced from the detection signal of the torque information detection means 5. Therefore, it is possible to provide an eccentric swing type reduction gear that reduces the influence of the moment load, which is an external disturbance, and can accurately detect the torque load.

[0048] The above is the description of the first embodiment.

[0049] [Second Embodiment] With reference to FIG. 4, the detection system 200 according to the second embodiment of the present invention will be described. FIG. 4 is a block diagram schematically showing an example of the detection system 200. The detection system 200 is a detection system in the eccentric swing type reduction gear 100 of the first embodiment and includes an abnormality detection unit 210.

[0050] The abnormality detection unit 210 detects an abnormality of the eccentric swing type reduction gear 100 when the detected value of the torque load detected by the torque information detection means 5 satisfies a preset condition. This condition is a case where the torque load shows a special mode different from the torque load during normal operation, such as when the torque load exceeds its allowable range, and may be defined by simulation based on the magnitude of the torque load, the mode of variation of the torque load, the peak of the torque load, etc. For example, the abnormality detection unit 210 may detect an abnormality of the eccentric swing type reduction gear 100 when the torque load exceeds its allowable range and notify the outside of the abnormality.

[0051] The above is the description of the second embodiment. The second embodiment has the same operations and effects as the first embodiment. Also, abnormalities in the eccentric swing type reduction gear 100 can be detected accurately.

[0052] [Third Embodiment] Referring to FIG. 5, a control system 300 according to a third embodiment of the present invention will be described. FIG. 5 is a block diagram schematically showing an example of the control system 300. The control system 300 includes the eccentric swing type reduction gear 100 of the first embodiment, an electric motor 310 that inputs rotation to the crankshaft of the eccentric swing type reduction gear 100, and a control unit 320. The control unit 320 controls the electric motor 310 using the detection value detected by the torque information detection means 5.

[0053] The control unit 320 may be configured to control the electric motor 310 so as to decelerate or stop the input rotation to the eccentric swing type reduction gear 100 when the detection value detected by the torque information detection means 5 exceeds a threshold value. In this case, the control system 300 performs torque control of the eccentric swing type reduction gear 100. With such a configuration, it is possible to perform complicated work that requires torque control with high accuracy at very low cost without using an external torque detector. Also, the control system 300 may be made to function as a torque limiter for the eccentric swing type reduction gear 100. In this case, control is performed so as to stop or decelerate when a predetermined torque or more is reached.

[0054] The above is the description of the third embodiment. The third embodiment has the same operations and effects as the first embodiment. Also, the torque load of the eccentric swing type reduction gear 100 can be controlled accurately.

[0055] The present invention has been described based on several embodiments above. These embodiments are examples, and it is understood by those skilled in the art that various modifications and changes are possible within the scope of the claims of the present invention, and such modified examples and changes are also within the scope of the claims of the present invention. Therefore, the descriptions and drawings in this specification should be treated as illustrative rather than restrictive.

[0056] (Modification example) The following describes a modification example. In the drawings and description of the modification example, the same or equivalent components and members as those in the embodiment are denoted by the same reference numerals. Descriptions overlapping with those in the embodiment are appropriately omitted, and configurations different from those in the embodiment are mainly described.

[0057] In the description of the embodiment, an example in which the torque information detection means 5 is provided on each external gear has been shown, but the present invention is not limited thereto. For example, the torque information detection means may be provided on a part of the plurality of external gears.

[0058] In the description of the embodiment, an example in which the torque information detection means 5 is provided in each first offset hole has been shown, but the present invention is not limited thereto. For example, the torque information detection means may be provided in a part of the plurality of first offset holes.

[0059] In the description of the embodiment, an example in which two torque information detection means 5 are provided in each first offset hole has been shown, but the present invention is not limited thereto. For example, a single torque information detection means may be provided in the first offset hole.

[0060] In the description of the embodiment, an example in which the first carrier 35 is an output member that outputs rotational power to the driven member 52 has been shown, but the present invention is not limited thereto. The speed reduction device may be an output member in which the casing outputs rotational power to the driven member.

[0061] In the description of the embodiment, an example in which the speed reduction device 100 includes two external gears 14 and 15 has been shown, but the present invention is not limited thereto. The speed reduction device may include one or three or more external gears.

[0062] In the description of the embodiment, an example in which the speed reduction device 100 is a so-called distribution type eccentric swing type speed reduction device has been shown, but the present invention is not limited thereto. The speed reduction device may be a so-called center crank type eccentric swing type speed reduction device in which the crankshaft is arranged on the axis of the internal gear.

[0063] Each of these modifications has the same operations and effects as the embodiments.

[0064] Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. The new embodiment produced by the combination has the effects of the embodiments and modifications combined.

Description of Reference Numerals

[0065] 4 Through hole, 5 Torque information detection means, 14, 15 External gear, 16 Internal gear, 24 Eccentric portion, 41, 42 First offset hole, 45, 46 Second offset hole, 47 Central hole, 58 Lead wire, 100 Eccentric swing type reduction gear, 200 Detection system, 300 Control system, 310 Electric motor.

Claims

1. It has a shaft, an eccentric portion that is eccentric from the shaft by a predetermined amount, an external gear that swings due to the eccentric portion, and an internal gear that meshes with the external gear, An eccentric swing type reduction gear provided with torque information detection means for detecting information regarding torque in the external gear.

2. The external gear is provided with a through hole that penetrates in the axial direction, The torque information detection means is attached to the inner circumference of the through hole. The eccentric swing type reduction gear according to Claim 1.

3. A plurality of the through holes are provided at positions offset from the rotation center of the external gear. The eccentric swing type reduction gear according to Claim 2.

4. The plurality of through holes include a plurality of second offset holes into which a plurality of crank shafts provided with the eccentric portions are inserted, and a first offset hole provided between the plurality of second offset holes in the circumferential direction, The torque information detection means is attached to the inner circumference of the first offset hole. The eccentric swing type reduction gear according to Claim 3.

5. The torque information detection means is attached to both sides in the circumferential direction of the first offset hole when assumed to be bisected in the circumferential direction. The eccentric swing type reduction gear according to Claim 4.

6. The external gear has a center hole, The lead wire of the torque information detection means extends from the center hole to the outside in the axial direction of the present eccentric swing type reduction gear. The eccentric swing type reduction gear according to Claim 1.

7. A detection system for the eccentric swing type reduction gear according to Claim 1, A detection system for detecting an abnormality of the eccentric swing type reduction gear based on a detection value detected by the torque information detection means.

8. The eccentric swing type reduction gear according to Claim 1, An electric motor for inputting rotation to the shaft of the eccentric swing type reduction gear, Comprising, A control system for controlling the electric motor using a detection value detected by the torque information detection means.

Images