Eccentric swing type speed reducer, detection system and control system

Abstract

The purpose of the present invention is to solve the problems of conventional eccentric oscillation type reduction gears, and to provide an eccentric oscillation type reduction gear capable of detecting a torque load with high precision. An eccentric oscillating speed reducer (100) according to an embodiment is provided with: a shaft; eccentric parts (24, 25) that are eccentric by a predetermined amount with respect to the shaft; external gears (14, 15) swung by the eccentric parts (24, 25); and an internal gear (16) that meshes with the external gears (14, 15), in which a torque information detection means (5) that detects information relating to torque is provided on the external gears (14, 15).

Description

[0001] This application claims priority based on Japanese Patent Application No. 2023-215103 filed on December 20, 2023. The entire content of the Japanese application is incorporated herein by reference. Technical Field

[0002] The present invention relates to an eccentric swing type reduction gear, a detection system, and a control system. Background Art

[0003] There is known a load detection system that detects a load applied to an eccentric swing type reduction gear. For example, in Patent Document 1, the following technique is described: The eccentric swing type reduction gear includes: a housing having an internal gear on its inner circumference; a support body rotatably supported by the housing via a main bearing; an external gear meshing with the internal gear; and a crankshaft that eccentrically rotates the external gear. For this eccentric swing type reduction gear, the load applied to the reduction gear is calculated based on the output of a strain gauge attached to the support body.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-347548

[0005] The present inventors have conducted research on the eccentric swing type reduction gear and obtained the following new understanding. It is conceivable to attach a strain gauge to the support body and detect the torque load applied to the eccentric swing type reduction gear from the detection signal of the strain gauge. However, the system described in Patent Document 1 has a structure in which the main bearing bears the moment load applied to the device, 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. Therefore, from the viewpoint of detecting the torque load with high accuracy, there is room for improvement in the conventional system. Summary of the Invention

[0006] The present invention has been made in view of such problems, and an object thereof is to provide an eccentric swing type reduction gear capable of detecting a torque load with high accuracy.

[0007] In order to solve the above problems, an eccentric swing type reduction gear according to an embodiment of the present invention includes: a shaft; an eccentric portion eccentric by a predetermined amount with respect to the shaft; an external gear swung by the eccentric portion; and an internal gear meshing with the external gear. In the eccentric swing type reduction gear, a torque information detection mechanism for detecting information related to torque is provided on the external gear.

[0008] Another embodiment of the present invention is a detection system. The 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 mechanism.

[0009] Another embodiment of the present invention is a control system. The control system includes the above-mentioned eccentric swing type reduction gear and a motor that inputs rotation to the shaft of the eccentric swing type reduction gear, and the control system controls the motor using the detection value detected by the torque information detection mechanism.

[0010] In addition, any combination of the above components or a manner of mutually replacing the components or expressions of the present invention between methods, systems, etc. is also effective as an embodiment of the present invention.

[0011] According to the present invention, there is provided an eccentric swing type reduction gear capable of detecting a torque load with high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional view showing an example of the eccentric swing type reduction gear according to the first embodiment.

[0013] Figure 2 It shows Figure 1 a front view of the external gear of the eccentric swing type reduction gear.

[0014] Figure 3 It shows Figure 1 a graph showing the relationship between the strain and the torque load of the eccentric swing type reduction gear.

[0015] Figure 4 It is a block diagram schematically showing an example of the detection system according to the second embodiment.

[0016] Figure 5 It is a block diagram schematically showing an example of the control system according to the third embodiment.

[0017] In the drawings: 4 - through hole, 5 - torque information detection mechanism, 14, 15 - external gears, 16 - internal gear, 24 - eccentric part, 41, 42 - first offset holes, 45, 46 - second offset holes, 47 - center hole, 58 - lead wire, 100 - eccentric swing type reduction gear, 200 - detection system, 300 - control system, 310 - motor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the embodiments and modification examples, the same or equivalent components and parts are denoted by the same reference numerals, and repeated descriptions are appropriately omitted. Also, in each drawing, for the sake of easy understanding, the dimensions of the components are appropriately enlarged or reduced. Also, in each drawing, a part of the components that are not important for explaining the embodiments is omitted.

[0019] Furthermore, terms including the numbers 1st, 2nd, etc. are used to describe various components, but these terms are only for the purpose of distinguishing one component from others, and the components are not limited by these terms.

[0020] [First Embodiment]

[0021] Reference Figure 1 and Figure 2 , the structure of the eccentric swing type reduction gear 100 (hereinafter sometimes simply referred to as "reduction gear 100") related to the first embodiment will be described. Figure 1 is a side sectional view showing the reduction gear 100. Figure 2 is a front view showing the external gears 14, 15 when viewed from the input side. The reduction gear 100 of the embodiment is an eccentric swing type reduction gear, which generates the rotation of one of the internal gear and the external gear by swinging the external gear meshing with the internal gear and outputs the generated rotation component from the output member to the driven member.

[0022] In Figure 1 example, the reduction gear 100 is a so-called distribution type eccentric swing type reduction gear in which the crankshaft is arranged at a position offset from the axis of the internal gear. The reduction gear 100 mainly includes: a torque information detection mechanism 5; a crankshaft 20; external gears 14, 15; an internal gear 16; wheel carriers 35, 36; a housing 60; main bearings 26, 27; crankshaft bearings 39, 40; and an input gear 23.

[0023] Hereinafter, the direction along the central axis La of the internal gear 16 will be referred to as the "axial direction", and the circumferential direction and the radial direction of the circle centered on the central axis La will be set as the "circumferential direction" and the "radial direction", respectively. And hereinafter, for convenience, one side in the axial direction (the right side in the figure) will be referred to as the input side, and the other side (the left side in the figure) will be referred to as the input opposite side.

[0024] In this specification, the load applied to the reduction gear 100 in the rotational direction centered on the central axis La will be referred to as the "torque load", and the load applied to the reduction gear 100 in the rotational direction centered on the axis orthogonal to the central axis La will be referred to as the "moment load".

[0025] The wheel carriers 35, 36 include a first wheel carrier 35 arranged on the side of the input opposite side of the external gears 14, 15 and a second wheel carrier 36 arranged on the side of the input side of the external gears 14, 15. The wheel carriers 35, 36 are supported by the housing 60 via the main bearings 26, 27 so as to be rotatable. The external gears 14, 15 include: a first external gear 14 arranged on the side of the input side of the first wheel carrier 35; and a second external gear 15 arranged on the side of the input opposite side of the second wheel carrier 36.

[0026] The main bearings 26 and 27 are disposed between the carriers 35 and 36 and the housing 60, and rotatably support the carriers 35 and 36 on the housing 60. The main bearings 26 and 27 in this example are angular contact roller bearings, but are not limited to this.

[0027] The housing 60 has a cylindrical shape surrounding the reduction gear 100, and an internal gear 16 is provided on its inner circumferential surface. The crankshaft bearings 39 and 40 are arranged between the crankshaft 20 and the wheel carriers 35 and 36, and support the crankshaft 20 so as to be rotatable relative to the wheel carriers 35 and 36. The crankshaft bearings 39 and 40 in this example are roller bearings, but are not limited to this.

[0028] The crankshaft 20 is equivalent to the shaft in the claims. The crankshafts 20 are arranged at positions offset from the central axis La of the internal gear 16 and three crankshafts 20 are arranged. Symbol Lb represents the rotation center line of the crankshaft 20. The three crankshafts 20 are arranged at equal intervals in the circumferential direction. Figure 1 In the figure, only one crankshaft 20 is shown. The crankshaft 20 has a plurality of eccentric portions 24 and 25 that are eccentric by a predetermined amount relative to the rotation center line Lb of the crankshaft 20 in order to allow the external gears 14 and 15 to swing. The crankshaft 20 of this example has two eccentric portions 24 and 25 whose eccentric phases are shifted by 180 degrees from each other. The eccentric portions 24 and 25 have an eccentric amount that can realize the deceleration action described later.

[0029] The crankshaft 20 is rotatably supported by the carriers 35 and 36 via crankshaft bearings 39 and 40. The crankshaft bearings 39 and 40 are arranged between the crankshaft 20 and the carriers 35 and 36 on the side of the external gears 14 and 15.

[0030] The input gear 23 is provided at the input side end of each crankshaft 20. Figure 1 In FIG. 2 , only one input gear 23 is shown. The input gear 23 transmits the rotation from the output shaft (not shown) of the motor to the crankshaft 20 .

[0031] refer to Figure 1 and Figure 2 , the external gears 14 and 15 will be described. The external gears 14 and 15 are provided corresponding to the eccentric parts 24 and 25 via roller bearings (ie, eccentric bearings 19), and are swung by the eccentric parts 24 and 25.

[0032] The external gears 14 and 15 are provided with through holes 4 that penetrate the external gears 14 and 15 in the axial direction. The through holes 4 include a plurality of first offset holes 41 and 42, a plurality of second offset holes 45 and 46, and a center hole 47. The center hole 47 is disposed at the center of the external gears 14 and 15.

[0033] There are three first offset holes 41 and 42 arranged at equal intervals in the circumferential direction. There are three second offset holes 45 and 46 arranged at equal intervals in the circumferential direction. The three first offset holes 41 are respectively arranged between a plurality of second offset holes 45 in the circumferential direction. The three first offset holes 42 are respectively arranged between a plurality of second offset holes 46 in the circumferential direction.

[0034] 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 respectively inserted into the second offset holes 45 and 46. A plurality of eccentric bearings 19 are present 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 outer gears 14 and 15 move while contacting the inner gear 16, whereby the outer gears 14 and 15 can swing.

[0035] The inner gear 16 has: an inner gear main body 18 integrated with the inner circumferential portion of the housing 60; and an outer pin 17 arranged in a pin groove formed in the inner gear main body 18. The outer pin 17 constitutes the inner teeth of the inner gear 16, which mesh with the outer teeth of the outer gears 14 and 15. The number of the outer pins 17 is slightly more than the number of the outer teeth of the outer gears 14 and 15 (one more in this example).

[0036] The swing pin 48 extends axially from the first wheel carrier 35 and is fixed to the second wheel carrier 36 by a bolt B1. The swing pin 48 is inserted through the first offset holes 41 and 42 in a state where there is a gap between the first offset holes 41 and 42 of the outer gears 14 and 15.

[0037] One of the first wheel carrier 35 and the housing 60 becomes an output member that outputs rotational power to the driven member 52, and the other becomes a fixed member fixed to an external member (not shown) for supporting the reduction gear 100.

[0038] Next, the torque information detection mechanism 5 will be described. From the viewpoint of detecting the torque load with high precision using the torque information detection mechanism, it is important to install the torque information detection mechanism at a position not easily affected by the moment load. In a reduction gear with a structure in which the main bearing bears the moment load, since the support body supported by the main bearing is affected by the moment load, it is difficult to completely eliminate the influence of the moment load from the detection signal of the torque information detection mechanism when the torque information detection mechanism is installed on the support body. Accordingly, the inventor came up with the idea of providing the torque information detection mechanism 5 on the outer gears 14 and 15. As a result of research, it was found that the outer gears 14 and 15 directly bear the torque load and are not easily affected by the moment load. Therefore, the following insight was obtained: by providing the torque information detection mechanism 5 on the outer gears 14 and 15, the torque load can be detected with high precision.

[0039] The torque information detection mechanism 5 only needs to be able to detect information related to torque, and its type is not limited. The torque information detection mechanism 5 of the embodiment detects the strain of the detected parts 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 mechanism 5 of the embodiment is a strain gauge, but is not limited thereto, as long as it can detect the amount of deformation of the detected part that is slightly stretched and deformed according to the stress as an electrical signal.

[0040] The torque information detection mechanism 5 can be installed at various parts of the external gears 14 and 15. As the installable parts, the tooth surface of the external gear (for example, the part that does not contact when the tooth surfaces mesh), the axial end face of the external gear (for example, between multiple offset holes on this end face, especially between the first offset hole and the second offset hole), the inner circumference of various holes, etc. can be cited. The torque information detection mechanism 5 of the embodiment is installed on the inner circumference of the through hole 4. At this time, the sensitivity to torque load is improved, and it is difficult to be affected by external interferences such as moment loads. The torque information detection mechanism 5 can be installed in the second offset holes 45, 46, the center hole 47 or other through holes 4. In the embodiment, the torque information detection mechanism 5 is installed in the first offset holes 41, 42. At this time, since the area where the sensor can be installed in the first offset holes 41, 42 is wide, the torque information detection mechanism 5 can be easily installed in a manner that does not contact other components.

[0041] For example, two lead wires are connected to each torque information detection mechanism 5. Figure 2 One of the two lead wires is shown. The symbol 58 represents the twelve lead wires of the six torque information detection mechanisms 5 provided on the external gear 14. The symbol 59 represents the twelve lead wires of the six torque information detection mechanisms 5 provided on the external gear 15. Figure 1 In

[0042] As Figure 1 and Figure 2 shown, the external gears 14 and 15 have a center hole 47, and the lead wires 58 and 59 of the torque information detection mechanism 5 extend from the center hole 47 to the axial outside of the reduction gear 100. At this time, since the wiring space is wide, even if the lead wires 58 and 59 are bent, it is not easy for the lead wires 58 and 59 to be wound around each other, which is more advantageous in terms of manufacturing cost than the case of providing a separate lead wire hole.

[0043] The lead wires 58 and 59 are led out to the input opposite side via the center hole 47 and are accommodated in the groove 38 formed on the side of the input opposite side of the first wheel carrier 35. The groove 38 extends from the radially inner side to the outer side, and the input opposite side of the groove 38 is covered by the driven member 52. The lead wires 58 and 59 extend radially outward via the groove 38 and are led out to the outside of the first wheel carrier 35.

[0044] As shown Figure 2 in the figure, the torque information detection mechanism 5 is installed on the circumferential surfaces, namely the P surface and the Q surface, on both circumferential sides that bisect the first offset holes 41 and 42 in the circumferential direction. In the first offset holes 41 and 42, the P surface and the Q surface are opposed to each other in the circumferential direction. The symbol 5P represents the torque information detection mechanism 5 installed on the P surface, and the symbol 5Q represents the torque information detection mechanism 5 installed on the Q surface. Each torque information detection mechanism 5P outputs an electrical detection value Sp that is approximately proportional to the magnitude of the strain generated on the P surface. Each torque information detection mechanism 5Q outputs an electrical detection value Sq that is approximately proportional to the magnitude of the strain generated on the Q surface. The electrical detection value includes a voltage value, a current value, a resistance value, etc.

[0045] The inventors found through research that: in the first offset holes 41 and 42, when the outer gears 14 and 15 receive a CW-direction torque load from the eccentric bearing, the P surface generates a greater strain than the Q surface, and when the outer gears 14 and 15 receive a CCW-direction torque load from the eccentric bearing, the Q surface generates a greater strain than the P surface.

[0046] Therefore, from the perspective of reducing the influence of external interference, when receiving a CW-direction torque load, the average value Spa of the electrical detection values Sp of the six torque information detection mechanisms 5P installed on the P surface can be used to estimate the magnitude of the strain (i.e., strain G1). Similarly, when receiving a CCW-direction torque load, the average value Sqa of the electrical detection values Sq of the six torque information detection mechanisms 5Q installed on the Q surface can be used to estimate the strain G1.

[0047] The inventors obtained the following insights through research: even when the load torque is set to be constant, the value of the strain varies periodically due to the change in the meshing position. As a result of research based on this insight, it was found that: by using the average value of the strains at three points, the influence of the change in the strain value caused by the change in the meshing position is offset. Therefore, by using the average value Spa or the average value Sqa, it is possible to distinguish the change in the strain value caused by the change in the load torque from the change in the strain value caused by the change in the meshing position, and thus it is possible to detect only the change in the load torque with high precision.

[0048] The strain G1 can be estimated by multiplying the average value Spa or the average value Sqa by a proportionality constant determined in advance through experiments or simulation tests. Compared with the case of using them together without considering the rotation direction, when using one of the electrical detection values Sp and Sq according to the rotation direction, it is possible to utilize one of the detection values Sp and Sq whose change with respect to the value of the torque load (strain) becomes larger according to the rotation direction. Since the other detection value Sp and Sq with a small change in value is not used, it is advantageous in terms of accuracy.

[0049] Reference Figure 3 An example of the relationship between the strain G1 and the torque load T1 will be described. Figure 3 Figure 3 An example of the relationship between the strain G1 and the torque load T1 detected in the reduction gear 100 of this example is shown in. In this figure, the horizontal axis represents the strain G1 estimated from the detection result of the torque information detection mechanism 5. The strain is a dimensionless number without a unit name. In this figure, the vertical axis represents the torque load T1 of the reduction gear 100 obtained using a torque meter capable of directly measuring the torque load. As Figure 3 Figure 3 can be seen, in the reduction gear 100, the torque load T1 within the normal use range varies linearly with respect to the strain G1 and has the correlation shown in Equation (1). Figure 3

[0050] Torque load T1 = 10 × Strain G1 ··· (1)

[0050]

[0051] In addition, the functional formula representing the correlation between the torque load T1 and the strain G1 can be calculated through an experiment with the following steps.

[0051]

[0052] (1) Apply a known torque load to the reduction gear and measure the strain value at this time.

[0052]

[0053] (2) Calculate the three-point average of the strain values obtained through measurement.

[0053]

[0054] (3) As

[0054] Figure 3 shown, plot the three-point average of the calculated strain values and the torque load on a graph. Figure 3

[0055] (4) Change the torque load and repeat steps (1) to (3).

[0055]

[0056] (5) Calculate the regression line from the plotted points by the least squares method as the functional formula representing the correlation.

[0056]

[0057] In addition,

[0057] Figure 3 the relationship between the strain G1 and the torque load T1 is an example, which varies according to the structure of the reduction gear, so it can be obtained according to each reduction gear. Thus, according to the reduction gear 100, the torque load can be accurately determined from the detection result of the torque information detection mechanism 5 of the reduction gear 100 without using a torque meter. Figure 3

[0058] Reference

[0058] Figure 1, the deceleration operation of the deceleration device 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 about the rotational center line Lb of the crankshaft 20, and the outer gears 14, 15 are swung by the eccentric portions 24, 25. When the outer gears 14, 15 swing, the meshing positions of the outer gears 14, 15 with the outer pins 17 of the inner gear 16 are sequentially displaced. As a result, every time the crankshaft 20 rotates once, the rotation of one of the outer gears 14, 15 and the inner gear 16 is equivalent to the difference between the number of teeth of the outer gears 14, 15 and the number of the outer pins 17 of the inner gear 16. When the outer gears 14, 15 rotate, the decelerated rotation is output from the first carrier 35 that rotates synchronously with the rotation component of the outer gears 14, 15, and the driven member 52 connected to the first carrier 35 is rotationally driven. When the inner gear 16 rotates, the decelerated rotation is output from the housing 60 that rotates integrally with the inner gear 16, and the driven member (not shown) connected to the housing 60 is rotationally driven.

[0059] Next, the features of the eccentric swing type deceleration device 100 having the above structure will be described. The eccentric swing type deceleration device 100 includes: eccentric portions 24, 25 that are eccentric by a predetermined amount; outer gears 14, 15 that are swung by the eccentric portions 24, 25; and an inner gear 16 that meshes with the outer gears 14, 15. The eccentric swing type deceleration device 100 is provided with a torque information detection mechanism 5 for detecting strain on the outer gears 14, 15.

[0060] According to this structure, since the torque information detection mechanism 5 is provided on the outer gears 14, 15 that are hardly affected by the torque load, the torque load with the influence of the torque load reduced can be determined from the detection signal of the torque information detection mechanism 5. Therefore, an eccentric swing type deceleration device that reduces the influence of external interference (i.e., torque load) and can detect the torque load with high accuracy can be provided.

[0061] The above is the description of the first embodiment.

[0062] [Second Embodiment]

[0063] Reference Figure 4 , the detection system 200 according to the second embodiment of the present invention will be described. Figure 4 is a block diagram schematically showing an example of the detection system 200. The detection system 200 is the detection system in the eccentric swing type deceleration device 100 of the first embodiment, and includes an abnormality detection unit 210.

[0064] When the detected value of the torque load detected by the torque information detection mechanism 5 satisfies a preset condition, the abnormality detection unit 210 detects that the eccentric swing type reduction gear 100 is abnormal. This condition is a case where the torque load represents a special state different from the torque load during normal operation (for example, the case where the torque load exceeds its allowable range, etc.), and can be defined by simulation tests based on the magnitude of the torque load, the change pattern of the torque load, the peak value of the torque load, etc. For example, the abnormality detection unit 210 can detect that the eccentric swing type reduction gear 100 is abnormal when the torque load exceeds its allowable range, and notify this abnormality to the outside.

[0065] The above is the description of the second embodiment. The second embodiment exhibits the same functions and effects as the first embodiment. Moreover, it is possible to detect abnormalities of the eccentric swing type reduction gear 100 with high precision.

[0066] [Third Embodiment]

[0067] Reference Figure 5 , a description will be given of the control system 300 according to the third embodiment of the present invention. Figure 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, a 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 motor 310 using the detected value detected by the torque information detection mechanism 5.

[0068] The control unit 320 may be configured as follows: when the detected value detected by the torque information detection mechanism 5 exceeds a threshold value, the motor 310 is controlled to decelerate or stop the input rotation to the eccentric swing type reduction gear 100. At this time, the control system 300 performs torque control of the eccentric swing type reduction gear 100. In such a configuration, it is possible to perform complex work that requires torque control with high precision at a very low cost without using an external torque detector. Moreover, the control system 300 can also function as a torque limiter for the eccentric swing type reduction gear 100. At this time, it is controlled to stop or decelerate when the torque becomes a specified torque or more.

[0069] The above is the description of the third embodiment. The third embodiment exhibits the same functions and effects as the first embodiment. Moreover, it is possible to control the torque load of the eccentric swing type reduction gear 100 with high precision.

[0070] As described above, the present invention has been described based on several embodiments. These embodiments are examples, and within the technical scope of the present invention, various modifications and changes can be made, and such modified examples and variations also belong to the technical scope of the present invention, which can be understood by those skilled in the art. Therefore, the descriptions and drawings in this specification should not be regarded as restrictive, but should be regarded as illustrative.

[0071] (Modified Example)

[0072] Hereinafter, a modified example will be described. In the drawings and descriptions of the modified example, the same reference numerals are assigned to the components and parts that are the same as or equivalent to those in the embodiment. The descriptions that are repeated with the embodiment will be appropriately omitted, and the structures different from the embodiment will be mainly described.

[0073] In the description of the embodiment, an example in which the torque information detection mechanism 5 is provided in each outer gear is shown, but the present invention is not limited thereto. For example, the torque information detection mechanism may also be provided on a part of the plurality of outer gears.

[0074] In the description of the embodiment, an example in which the torque information detection mechanism 5 is provided in each first offset hole is shown, but the present invention is not limited thereto. For example, the torque information detection mechanism may also be provided on a part of the plurality of first offset holes.

[0075] In the description of the embodiment, an example in which two torque information detection mechanisms 5 are provided in each first offset hole is shown, but the present invention is not limited thereto. For example, one torque information detection mechanism may also be provided in the first offset hole.

[0076] In the description of the embodiment, an example in which the first wheel carrier 35 is an output member that outputs rotational power to the driven member 52 is shown, but the present invention is not limited thereto. In the reduction gear, the housing may also be an output member that outputs rotational power to the driven member.

[0077] In the description of the embodiment, an example in which the reduction gear 100 includes two outer gears 14 and 15 is shown, but the present invention is not limited thereto. The reduction gear may also include one or three or more outer gears.

[0078] In the description of the embodiment, an example in which the reduction gear 100 is a so-called distribution type eccentric swing type reduction gear is shown, but the present invention is not limited thereto. The reduction gear may also be a so-called central crank type eccentric swing type reduction gear in which the crankshaft is disposed on the axis of the internal gear.

[0079] These respective modified examples also have the same functions and effects as the embodiment.

[0080] Any combination of the above-described embodiments and variations is also effective as an embodiment of the present invention. The new embodiments generated by the combination have the effects of the combined embodiments and variations respectively.

Claims

1. An eccentric swing type reduction gear, characterized in that: have: axis; An eccentric portion, eccentric by a predetermined amount relative to the shaft; an external gear, which is swung by the eccentric portion; and an internal gear meshing with the external gear, The external gear is provided with a torque information detection mechanism for detecting information related to the torque.

2. The eccentric oscillating type reduction gear device according to claim 1, characterized in that: The external gear is provided with a through hole which penetrates the external gear in the axial direction. The torque information detection mechanism is installed on the inner periphery of the through hole.

3. The eccentric oscillating speed reduction device according to claim 2, characterized in that: The external gear is provided with a plurality of through holes at positions offset from the rotation center.

4. The eccentric oscillating type reduction gear device according to claim 3, characterized in that: The plurality of through holes include a plurality of second offset holes for inserting a plurality of crankshafts provided with the eccentric portion, and a first offset hole provided between the plurality of second offset holes in the circumferential direction. The torque information detection mechanism is mounted on the inner periphery of the first offset hole.

5. The eccentric oscillating type reduction gear device according to claim 4, characterized in that: When the first offset hole is divided into two equal parts in the circumferential direction, the torque information detection mechanism is respectively installed on both sides of the first offset hole in the circumferential direction.

6. The eccentric oscillating speed reduction device according to claim 1, characterized in that: The outer gear has a central hole, The lead wire of the torque information detection mechanism extends from the center hole toward the axially outer side of the eccentric oscillating type reduction gear transmission.

7. A detection system, which is the detection system of the eccentric oscillating type reduction gear device according to claim 1, characterized in that: The detection system detects abnormality of the eccentric oscillating speed reduction device based on the detection value detected by the torque information detection mechanism.

8. A control system, characterized in that: have: The eccentric oscillating speed reduction device according to claim 1; and The electric motor inputs rotation to the shaft of the eccentric oscillating type speed reducer, The control system controls the electric motor using a detection value detected by the torque information detection mechanism.

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