Rotating mechanisms and robots

Abstract

To provide a rotation mechanism capable of suppressing deformation of an attachment portion attachable to a mating member and disposed in a projecting manner, and a robot including the rotation mechanism.SOLUTION: A case 2 has: a cylindrical main body portion 21 for housing a carrier portion 5 and an input-side angular ball bearing 6 inside and kept into contact with the input-side angular ball bearing 6 at an inner peripheral surface; and a flange portion 22 projecting from the main body portion 21 in a direction intersecting with a direction along an axis of the main body portion 21. The main body portion 21 is disposed in a manner of extending from the flange portion 22 in a direction along the axis with respect to an outer ring 6a of an input-side angular ball bearing 6 and has an attachment portion 23 attachable to the mating member, and an input-side angular portion C1 between the flange portion 22 and the attachment portion 23 is disposed on a position at a tip side of the attachment portion 23 with respect to a position where an action line L1 of the input-side angular ball bearing 6 and an outer peripheral surface of the main body portion 21 intersect.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a rotation mechanism and a robot.

Background Art

[0002] For example, Patent Document 1 discloses an eccentric oscillating gear device. The eccentric oscillating gear device disclosed in Patent Document 1 includes a main bearing that rotatably holds a carrier relative to an outer cylinder. Further, Patent Document 2 discloses a drive device. The drive device disclosed in Patent Document 2 includes a main bearing disposed between a carrier and a casing.

Prior Art Literature

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problem to be Solved by the Invention

[0004] The eccentric oscillating gear device disclosed in Patent Document 1 and the drive device disclosed in Patent Document 2 include an angular contact ball bearing as a main bearing that rotatably supports a rotating body. For example, such a rotation mechanism that rotatably supports a rotating body with the main bearing includes a case that accommodates the main bearing. A part of such a case is used as a mounting portion that can be attached to a counterpart member such as a motor or a robot. However, the preload applied to the main bearing may deform the mounting portion. If the mounting portion deforms and deviates from the specified dimensional tolerance, there arises a problem that the rotation mechanism cannot be attached to the counterpart member.

[0005] The present invention has been made in view of the above-mentioned problems, and provides a rotating mechanism that can suppress deformation of a mounting portion that can be attached to a mating member, and a robot equipped with this rotating mechanism. [Means for solving the problem]

[0006] A rotating mechanism according to a first aspect of the present invention comprises a case, a rotating body, and a bearing positioned between the case and the rotating body to rotatably support the rotating body relative to the case, wherein the case has a cylindrical main body portion that houses the rotating body and the bearing inside and has the bearing in contact with its inner circumferential surface, and a flange portion positioned from the main body portion in a direction intersecting the direction along the axis of the main body portion, the main body portion has a mounting portion provided from the flange portion in a direction along the axis and capable of being attached to a mating member, and the corner portion between the flange portion and the mounting portion is positioned on the tip side of the mounting portion from the position where the line of action of the bearing intersects with the outer circumferential surface of the main body portion.

[0007] The part of the case that receives the strongest preload acting on the bearing is the part located on the bearing's line of action. In the first aspect of the present invention, the corner between the flange and the mounting part is positioned at a location displaced toward the tip of the mounting part from the position where the bearing's line of action intersects with the outer circumferential surface of the main body. Therefore, the bearing's line of action passes through the inside of the flange. The flange is positioned to protrude from the cylindrical main body in a direction intersecting the axis of the main body. Thus, the part of the case with the flange has a larger thickness dimension in the direction intersecting the axial direction of the main body and is a more rigid part compared to the part of the case without the flange. In other words, in the first aspect of the present invention, the bearing's line of action passes through the rigid part of the case. Therefore, the preload acting on the bearing can be received by the rigid part of the case, and deformation of the case due to the preload can be suppressed. Thus, according to the first aspect of the present invention, even if the mounting part provided on the case is formed to protrude from the surrounding parts, deformation of the mounting part can be suppressed.

[0008] In the above configuration, the main body portion may be provided extending from the flange portion in a direction along the axis, beyond the outer ring of the bearing.

[0009] In the above configuration, the bearing is an angular contact ball bearing, and the corner portion may be positioned on the tip side of the mounting portion from the position where a line perpendicular to the central axis of the angular contact ball bearing and passing through the center of the rolling element intersects with the outer circumferential surface of the main body.

[0010] In the above configuration, the case may have a recess formed by connecting to the corner and recessing a part of the case.

[0011] In the above configuration, the case may have a groove formed on the outer circumferential surface of the mounting portion along the circumferential direction centered on the central axis of the bearing.

[0012] In the above configuration, the line of action may be inclined with respect to the axis such that it approaches the axis as it approaches the tip of the mounting portion with respect to the direction along the axis of the main body.

[0013] In the above configuration, the inner diameter of the main body is 60 mm or more and less than 200 mm, the wall thickness of the mounting portion is 3 mm or more and 10 mm or less, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 5 μm or more and 50 μm or less, and the preload acting on the angular contact ball bearing housed inside the main body may be 1000 N or more and 50000 N or less.

[0014] In the above configuration, the inner diameter of the main body is 200 mm or more and less than 290 mm, the wall thickness of the mounting portion is 7 mm or more and 18 mm or less, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 5 μm or more and 70 μm or less, and the preload acting on the angular contact ball bearing housed inside the main body may be 15,000 N or more and 80,000 N or less.

[0015] In the above configuration, the inner diameter of the main body is 290 mm or more and less than 390 mm, the wall thickness of the mounting portion is 14 mm or more and 28 mm or less, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 15 μm or more and 70 μm or less, and the preload acting on the angular contact ball bearing housed inside the main body may be 30,000 N or more and 130,000 N or less.

[0016] A second aspect of the present invention provides a rotating mechanism comprising a case, a rotating body, and an angular contact ball bearing positioned between the case and the rotating body to rotatably support the rotating body relative to the case, wherein the case has a cylindrical main body portion that houses the rotating body and the angular contact ball bearing inside and has the angular contact ball bearing in contact with its inner circumferential surface, and a flange portion that protrudes from the main body portion in a direction intersecting the direction along the axis of the main body portion, the main body portion has a mounting portion that extends from the flange portion in a direction along the axis than the outer ring of the angular contact ball bearing and is attachable to a mating member, the line of action of the angular contact ball bearing is inclined with respect to the axis with respect to the direction along the axis of the main body portion that approaches the axis as it approaches the tip of the mounting portion, and the corner between the flange portion and the mounting portion is The mounting portion is positioned on the tip side of the position where a line perpendicular to the central axis of the angular contact ball bearing and passing through the center of the rolling element intersects with the outer surface of the main body, the case further has a recess formed by connecting to the corner and recessing a part of the case, and a groove formed on the outer surface of the mounting portion along the circumferential direction centered on the central axis of the angular contact ball bearing, the inner diameter of the main body is 60 mm or more and less than 200 mm, the wall thickness of the mounting portion is 3 mm or more and less than 10 mm, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 5 μm or more and less than 50 μm, and the preload acting on the angular contact ball bearing housed inside the main body is 1000 N or more and less than 50000 N.

[0017] The preload acting on an angular contact ball bearing can be considered as a vector that extends radially outward from the center of the rolling elements along the line of action. This vector is called the preload vector. The preload vector can be decomposed into a component along the central axis of the angular contact ball bearing and a component along a line perpendicular to the central axis of the angular contact ball bearing. The component along the line perpendicular to the central axis of the angular contact ball bearing starts from the center of the rolling elements and extends radially toward the angular contact ball bearing, causing deformation of the mounting portion that protrudes beyond the outer ring of the angular contact ball bearing.

[0018] In the second aspect of the present invention, the corner between the flange and the mounting portion is positioned on the tip side of the mounting portion, relative to the position where a line perpendicular to the central axis of the angular contact ball bearing and passing through the center of the rolling element intersects with the outer circumferential surface of the main body. Therefore, among the components included in the preload load vector, the component that causes deformation of the mounting portion is directed toward the flange portion. The flange portion is formed by protruding from the cylindrical main body portion in a direction intersecting the direction along the axis of the main body portion. Thus, the part of the case where the flange portion is provided has a larger thickness dimension in the direction intersecting the axial direction of the main body portion and is a part with high rigidity compared to the part of the case where the flange portion is not provided. In other words, in the rotating mechanism according to the second aspect of the present invention, the component included in the preload load vector that causes deformation of the mounting portion can be received by the part of the case with high rigidity. Therefore, deformation of the case due to the preload load vector can be suppressed. Thus, according to the rotating mechanism according to the second aspect of the present invention, even if the mounting portion provided on the case is formed to protrude toward the surrounding part, deformation of the mounting portion can be suppressed.

[0019] Furthermore, in the rotating mechanism according to the second aspect of the present invention, the case further has a recess formed by recessing a part of the case at the corner, and a groove formed on the outer circumferential surface of the mounting portion along the circumferential direction centered on the central axis of the angular contact ball bearing. By providing these recesses and grooves, a part of the main body becomes thinner than if they were not provided. However, in the rotating mechanism according to the second aspect of the present invention, the component included in the preload vector that causes deformation of the mounting portion can be received by the part of the case with high rigidity, so deformation of the mounting portion can be suppressed even if recesses and grooves are provided.

[0020] Furthermore, in the rotating mechanism according to the second aspect of the present invention, the inner diameter of the main body is 60 mm or more and less than 200 mm, the wall thickness of the mounting portion is 3 mm or more and 10 mm or less, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 5 μm or more and 50 μm or less, and the preload acting on the angular contact ball bearing housed inside the main body is 1000 N or more and 50000 N or less. As a result, the deformation of the mounting portion can be kept within the h7 tolerance range of the Japanese Industrial Standards.

[0021] A rotating mechanism according to a third aspect of the present invention comprises a case, a rotating body, and an angular contact ball bearing positioned between the case and the rotating body and supporting the rotating body rotatably with respect to the case, wherein the case has a cylindrical main body portion that houses the rotating body and the angular contact ball bearing inside and has the angular contact ball bearing in contact with its inner circumferential surface, and a flange portion that protrudes from the main body portion in a direction intersecting the direction along the axis of the main body portion, the main body portion has a mounting portion that extends from the flange portion in a direction along the axis than the outer ring of the angular contact ball bearing and is attachable to a mating member, the line of action of the angular contact ball bearing is inclined with respect to the axis with respect to the direction along the axis of the main body portion and approaches the axis towards the tip of the mounting portion, and the corner portion between the flange portion and the mounting portion is the The mounting portion is positioned on the tip side of the position where a line perpendicular to the central axis of the angular contact ball bearing and passing through the centers of the rolling elements intersects with the outer circumferential surface of the main body, the case further has a recess formed by connecting to the corner and recessing a part of the case, and a groove formed on the outer circumferential surface of the mounting portion along the circumferential direction centered on the central axis of the angular contact ball bearing, the inner diameter of the main body is 200 mm or more and less than 290 mm, the wall thickness of the mounting portion is 7 mm or more and less than 18 mm, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 5 μm or more and less than 70 μm, and the preload acting on the angular contact ball bearing housed inside the main body is 15,000 N or more and less than 80,000 N.

[0022] In the rotation mechanism according to the third aspect of the present invention, a corner between the flange portion and the mounting portion is arranged at a position on the distal end side of the mounting portion relative to a position where a line orthogonal to the central axis of the angular contact ball bearing and passing through the center of the rolling elements intersects with the outer peripheral surface of the main body portion. Therefore, among the components included in the preload load vector, the component that causes deformation of the mounting portion is directed toward the flange portion. The flange portion is formed to protrude from the cylindrical main body portion in a direction intersecting the direction along the axis of the main body portion. Therefore, the portion of the case where the flange portion is provided has a larger thickness dimension in the direction intersecting the axial direction of the main body portion and higher rigidity than the portion of the case where the flange portion is not provided. That is, in the rotation mechanism according to the third aspect of the present invention, among the components included in the preload load vector, the component that causes deformation of the mounting portion can be received by the high-rigidity portion of the case. Accordingly, deformation of the case caused by the preload load vector can be suppressed. Therefore, according to the rotation mechanism according to the third aspect of the present invention, even if the mounting portion provided on the case is formed to protrude relative to a surrounding portion, deformation of the mounting portion can be suppressed.

[0023] Furthermore, in the rotation mechanism according to the third aspect of the present invention, the case further includes a recess formed by recessing a part of the case at the corner portion, and a groove portion formed along the circumferential direction centered on the central axis of the angular contact ball bearing on the outer peripheral surface of the mounting portion. By providing the recess and the groove portion, a part of the main body portion becomes thinner than when they are not provided. However, in the rotation mechanism according to the third aspect of the present invention, among the components included in the preload load vector, the component that causes deformation of the mounting portion can be received by the high-rigidity portion of the case, so deformation of the mounting portion can be suppressed even when the recess and the groove portion are provided.

[0024] Furthermore, in the rotating mechanism according to the third aspect of the present invention, the inner diameter of the main body is 200 mm or more and less than 290 mm, the wall thickness of the mounting part is 7 mm or more and 18 mm or less, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 5 μm or more and 70 μm or less, and the preload acting on the angular contact ball bearing housed inside the main body is 15,000 N or more and 80,000 N or less. As a result, the deformation of the mounting part can be kept within the h7 tolerance range of the Japanese Industrial Standards.

[0025] A rotating mechanism according to a fourth aspect of the present invention comprises a case, a rotating body, and an angular contact ball bearing positioned between the case and the rotating body and supporting the rotating body rotatably with respect to the case, wherein the case has a cylindrical main body portion that houses the rotating body and the angular contact ball bearing inside and has the angular contact ball bearing in contact with its inner circumferential surface, and a flange portion that protrudes from the main body portion in a direction intersecting the direction along the axis of the main body portion, the main body portion has a mounting portion that extends from the flange portion in a direction along the axis than the outer ring of the angular contact ball bearing and is attachable to a mating member, the line of action of the angular contact ball bearing is inclined with respect to the axis with respect to the direction along the axis of the main body portion and approaches the axis towards the tip of the mounting portion, and the corner portion between the flange portion and the mounting portion is the angular contact ball bearing The mounting portion is positioned on the tip side of the position where a line perpendicular to the central axis of the angular contact ball bearing and passing through the center of the rolling element intersects with the outer circumferential surface of the main body, the case further has a recess formed by connecting to the corner and recessing a part of the case, and a groove formed on the outer circumferential surface of the mounting portion along the circumferential direction centered on the central axis of the angular contact ball bearing, the inner diameter of the main body is 290 mm or more and less than 390 mm, the wall thickness of the mounting portion is 14 mm or more and less than 28 mm, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 15 μm or more and less than 70 μm, and the preload acting on the angular contact ball bearing housed inside the main body is 30,000 N or more and less than 130,000 N.

[0026] In the rotation mechanism according to the fourth aspect of the present invention, the corner between the flange portion and the mounting portion is located at a position closer to the distal end side of the mounting portion than a position where a line that is orthogonal to the central axis of the angular ball bearing and passes through the center of the rolling element intersects the outer peripheral surface of the main body portion. For this reason, among the components included in the preload load vector, the component that causes deformation of the mounting portion is directed toward the flange portion. The flange portion is formed to protrude from the cylindrical main body portion in a direction intersecting the direction along the axis of the main body portion. Therefore, the portion of the case where the flange portion is provided has a larger thickness dimension in the direction intersecting the axial direction of the main body portion and higher rigidity compared to the portion of the case where the flange portion is not provided. That is, in the rotation mechanism according to the fourth aspect of the present invention, among the components included in the preload load vector, the component that causes deformation of the mounting portion can be received by the portion of the case having high rigidity. Therefore, deformation of the case due to the preload load vector can be suppressed. Therefore, according to the rotation mechanism of the fourth aspect of the present invention, even if the mounting portion provided on the case is formed to protrude relative to the surrounding portion, deformation of the mounting portion can be suppressed.

[0027] Further, in the rotation mechanism according to the fourth aspect of the present invention, the case further includes a recess formed by recessing a part of the case at the corner, and a groove portion formed along the circumferential direction centered on the central axis of the angular ball bearing on the outer peripheral surface of the mounting portion. By providing these recesses and the groove portion, a part of the main body portion becomes thinner than when they are not provided. However, in the rotation mechanism according to the fourth aspect of the present invention, among the components included in the preload load vector, the component that causes deformation of the mounting portion can be received by the portion of the case having high rigidity, so that deformation of the mounting portion can be suppressed even if the recess or the groove portion is provided.

[0028] Furthermore, in the rotating mechanism according to the fourth aspect of the present invention, the inner diameter of the main body is 290 mm or more and less than 390 mm, the wall thickness of the mounting part is 14 mm or more and 28 mm or less, the outer diameter of the angular contact ball bearing when removed from inside the main body is larger than the inner diameter of the main body by a range of 15 μm or more and 70 μm or less, and the preload acting on the angular contact ball bearing housed inside the main body is 30,000 N or more and 130,000 N or less. As a result, the deformation of the mounting part can be kept within the Japanese Industrial Standards h7 tolerance range.

[0029] A robot according to a fifth aspect of the present invention comprises a first member, a second member, and a rotation mechanism provided between the first member and the second member, which connects the second member to the rotation of the first member, wherein the rotation mechanism comprises a case, a rotating body, and a bearing located between the case and the rotating body, which rotatably supports the rotating body relative to the case, wherein the case has a cylindrical main body portion that houses the rotating body and the bearing inside and has the bearing in contact with its inner circumferential surface, and a flange portion arranged from the main body portion in a direction intersecting the direction along the axis of the main body portion, wherein the main body portion has a mounting portion provided from the flange portion in a direction along the axis and which can be attached to a mating member, and the corner portion between the flange portion and the mounting portion is located on the tip side of the mounting portion from the position where the line of action of the bearing intersects with the outer circumferential surface of the main body portion.

[0030] In the rotating mechanism, the corner between the flange and the mounting portion is positioned closer to the tip of the mounting portion than the point where the bearing's line of action intersects with the outer circumferential surface of the main body. Therefore, the bearing's line of action passes through the interior of the flange. The flange is positioned to protrude from the cylindrical main body in a direction intersecting the axis of the main body. Thus, the portion of the case with the flange has a larger thickness dimension in the direction intersecting the axial direction of the main body and is a more rigid portion compared to the portion of the case without the flange. In other words, in the rotating mechanism, the bearing's line of action passes through the rigid portion of the case. Therefore, the preload acting on the bearing can be received by the rigid portion of the case, and deformation of the case due to the preload can be suppressed. Thus, with the rotating mechanism, even if the mounting portion provided on the case is formed to protrude from the surrounding portion, deformation of the mounting portion can be suppressed. A robot according to the fifth aspect of the present invention is equipped with the above-described rotating mechanism. Therefore, deformation of the mounting portion of the rotating mechanism is suppressed, and the rotating mechanism can be reliably connected to the first member or the second member. [Effects of the Invention]

[0031] The above-described rotating mechanism and robot can suppress deformation of the mounting portion, which is provided to allow attachment to the mating member. [Brief explanation of the drawing]

[0032] [Figure 1] This figure includes a cross-sectional view showing the schematic configuration of a gearbox in the first embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view of a gearbox according to the first embodiment of the present invention. [Figure 3] This is an enlarged view of the main part of Figure 3. [Figure 4] This is a cross-sectional view taken along line IV-IV in Figure 2. [Figure 5] This is an enlarged view of the main parts showing the schematic configuration of the gearbox in the second embodiment of the present invention. [Figure 6] This is a schematic diagram of a collaborative robot according to a third embodiment of the present invention. [Modes for carrying out the invention]

[0033] Hereinafter, a rotating mechanism and a robot according to embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments described below, corresponding components may be denoted by the same reference numerals and their descriptions may be omitted. In the following description, expressions indicating relative or absolute arrangements such as "parallel," "orthogonal," "center," and "coaxial" will not only strictly represent such arrangements, but will also represent states of relative displacement with tolerances or angles and distances that allow the same function to be obtained.

[0034] (First Embodiment) Figure 1 is a diagram including a cross-sectional view showing the schematic configuration of a reduction gear 1 according to the first embodiment. For example, the reduction gear 1 is installed in the joint portion of a robot. In Figure 1, the reduction gear 1 is located between a motor bracket 200 (an example of a mating member in the claims) and the arm 500 of the robot. The motor bracket 200 is located between a servo motor 300 and the reduction gear 1. The motor bracket 200 is fixed to the reduction gear 1 by a plurality of bolts 400.

[0035] The motor bracket 200 is formed in an annular shape with a central axis La as shown in Figure 1, so as to surround the output shaft 301 of the servo motor 300 from the radially outer side. The central axis La of the motor bracket 200 is positioned to overlap with the central axis Lb of the servo motor 300 when viewed from a direction along the central axis La.

[0036] The motor bracket 200 includes a mounting portion 201 to which the reduction gear 1 is attached. The mounting portion 201 is provided protruding from the main body portion 202 of the motor bracket 200 toward the reduction gear 1 in a direction along the central axis La. When viewed from the direction along the central axis La, the mounting portion 201 is formed to have a smaller thickness than the main body portion 202. As shown in Figure 1, the mounting portion 201 into which the mounting portion 201 is inserted into the mounting portion 201, which will be described later. In addition, the end face 203 of the mounting portion 201 toward the reduction gear 1 in the direction along the central axis La abuts against the flange portion 22 of the reduction gear 1, which will be described later. The servo motor 300 is fixed to the end of the motor bracket 200 opposite to the reduction gear 1 in the direction along the central axis La.

[0037] The servo motor 300 is fixed to the motor bracket 200 by, for example, bolts (not shown). The servo motor 300 is a power source that generates power to rotate the arm 500. The servo motor 300 has an output shaft 301 that protrudes in a direction along the central axis Lb. The output shaft 301 rotates about the central axis Lb. As shown in Figure 1, an input gear 302 connected to a transmission gear 11 of the reduction gear 1 (described later) is provided on the outer circumferential surface of the tip of the output shaft 301.

[0038] Alternatively, an input shaft connected to the transmission gear 11 may be provided on the motor bracket 200, separate from the output shaft 301 of the servo motor 300. In this case, an input gear is provided on the outer circumferential surface of the tip of the input shaft, and the input shaft is connected to the output shaft 301 of the servo motor 300. For example, the input shaft can be made a hollow shaft, and the output shaft 301 of the servo motor 300 can be inserted into the input shaft to connect the input shaft and the output shaft 301 of the servo motor 300.

[0039] The arm 500 is fixed to the reduction gear 1, for example, by bolts 600. The arm 500 receives an output from the reduction gear 1 that is a reduced rotational speed from the power of the servo motor 300, and is rotationally driven around the central axis Lc of the reduction gear 1. The arm 500 is fixed to the carrier section 5 of the reduction gear 1, which will be described later.

[0040] [Reducer] Figure 2 is a schematic enlarged cross-sectional view of the gearbox 1 of this embodiment. The gearbox 1 is a rotation mechanism that includes a carrier section 5, which will be described later, that rotates around a central axis Lc, and changes the rotational speed of the power input from the servo motor 300 and outputs it at the carrier section 5. In the following description, the servo motor 300 side in the direction along the central axis Lc will be referred to as the input side, and the arm 500 side in the direction along the central axis Lc will be referred to as the output side.

[0041] As shown in Figure 2, the gearbox 1 comprises a case 2 and a gear reduction mechanism 3. The case 2 has a main body 21 and a flange 22. The main body 21 is formed in a cylindrical shape with a central axis Lc as its center. In other words, the central axis Lc of the gearbox 1 is also the axis of the main body 21. Both sides of the main body 21 in the direction along the central axis Lc (i.e., the input side and the output side) are open. The main body 21 houses the gear reduction mechanism 3 inside. The gear reduction mechanism 3 comprises a carrier 5 and an input-side angular contact ball bearing 6. In other words, the main body 21 houses the carrier 5 and the input-side angular contact ball bearing 6 inside.

[0042] Furthermore, the input-side end of case 2 is used as a mounting portion 23 that can be attached to the motor bracket 200. The mounting portion 23 is provided extending from the input-side end face 22a of the flange portion 22 in a direction along the central axis Lc (axis) beyond the outer ring 6a of the input-side angular contact ball bearing 6, which will be described later. In other words, the mounting portion 23 is provided extending from the input-side end face 22a of the flange portion 22 in a direction along the central axis Lc (axis) beyond the outer ring 6a of the input-side angular contact ball bearing 6, which will be described later. The tip surface 23a of this mounting portion 23 is located on the motor bracket 200 side beyond the outer ring 6a of the input-side angular contact ball bearing 6. Also, when viewed from the direction along the central axis Lc, the mounting portion 23 is formed in an annular shape with the central axis Lc as the center. The mounting portion 23 is inserted into the mounting portion 201 of the motor bracket 200. The outer circumferential surface of the mounting portion 23 is in contact with, for example, the inner circumferential surface of the mounting portion 201.

[0043] Figure 3 is an enlarged view including the connection point between the flange portion 22 and the mounting portion 23 in Figure 2. As shown in Figure 3, the outer circumferential surface of the mounting portion 23 is provided with a groove 23b in which the O-ring 700 is placed. The groove 23b is formed continuously along the circumferential direction centered on the central axis Lc when viewed from a direction along the central axis Lc. The groove 23b is formed recessed inward in the radial direction centered on the central axis Lc from the outer circumferential surface of the mounting portion 23.

[0044] Furthermore, a recess 23c is provided at the base of the mounting portion 23 on the flange portion 22 side. The recess 23c is formed by recessing the outer circumferential surface of the mounting portion 23 inward in the radial direction centered on the central axis Lc. In other words, the recess 23c is formed by recessing a part of the case 2. This recess 23c is a so-called concealed portion.

[0045] As shown in Figure 3, a corner is formed between the flange portion 22 and the mounting portion 23 by connecting the flange portion 22 and the mounting portion 23. In this embodiment, this corner is called the input-side corner C1. More specifically, the input-side corner C1 is formed between the end face 22a of the flange portion 22 and the outer circumferential surface of the mounting portion 23 (the bottom surface 23d of the recess 23c) by connecting the end face 22a of the flange portion 22 and the outer circumferential surface of the mounting portion 23. The input-side corner C1 may be a so-called sharp corner or a so-called rounded corner. In other words, the input-side corner C1 may be formed by bending and connecting the end face 22a of the flange portion 22 and the outer circumferential surface of the mounting portion 23. Alternatively, the input-side corner C1 may be formed by curving and connecting the end face 22a of the flange portion 22 and the outer circumferential surface of the mounting portion 23. The aforementioned recess 23c is connected to the input-side corner C1.

[0046] Furthermore, the output-side end face 22b of the flange portion 22 is connected to the outer circumferential surface of the main body portion 21, thereby forming a corner between the end face 22b and the main body portion 21. In this embodiment, this corner is referred to as the output-side corner portion C2. The output-side corner portion C2, like the input-side corner portion C1, may be a so-called sharp corner or a so-called rounded corner. In addition, a recess 21a connected to the output-side corner portion C2 is provided on the outer circumferential surface of the main body portion 21.

[0047] The flange portion 22 is formed to protrude from the main body portion 21 in a direction intersecting the direction along the central axis Lc of the main body portion 21. In other words, the flange portion 22 is arranged to protrude radially outward from the outer circumferential surface of the main body portion 21 with respect to the central axis Lc. When viewed from the direction along the central axis Lc, the flange portion 22 is provided continuously in the circumferential direction with respect to the central axis Lc.

[0048] The input-side end face 22a of the flange portion 22 is the contact surface with the mounting portion 201 of the motor bracket 200. The exit-side end face 22b of the flange portion 22 is the contact surface with the head of the bolt 400. The flange portion 22 is provided with multiple bolt holes 22c that penetrate from end face 22a to end face 22b. A bolt 400 is inserted into each of these bolt holes 22c. Figure 4 is a cross-sectional view taken along line IV-IV of Figure 2. As shown in this figure, the bolt holes 22c are formed discretely along the circumferential direction centered on the central axis Lc.

[0049] Furthermore, as shown in Figure 2, numerous pin grooves 21b are formed on the inner circumferential surface of the main body 21. Each of these pin grooves 21b is provided to extend along the central axis Lc and is formed in a semicircular shape when viewed in the direction along the central axis Lc. These pin grooves 21b are arranged at equal intervals in the circumferential direction with respect to the central axis Lc.

[0050] As shown in Figure 2, the reduction gear section 3 comprises an internal tooth pin 4, a carrier section 5, an input-side angular contact ball bearing 6, an output-side angular contact ball bearing 7, a plurality (for example, three) crankshafts 8, a first oscillating gear 9, a second oscillating gear 10, and a plurality of transmission gears 11.

[0051] An internal tooth pin 4 is provided for each pin groove 21b. Specifically, each internal tooth pin 4 is fitted into its corresponding pin groove 21b and is positioned to extend in a direction along the central axis Lc. As a result, the numerous internal tooth pins 4 are arranged at equal intervals along the circumferential direction with respect to the central axis Lc. The external teeth 9a of the first oscillating gear 9 and the external teeth 10a of the second oscillating gear 10 mesh with these internal tooth pins 4.

[0052] The carrier section 5 is housed inside the case 2, positioned coaxially with the case 2. The carrier section 5 rotates relative to the case 2 in the circumferential direction about its central axis Lc. Specifically, the carrier section 5 is positioned radially inward of the case 2 and is supported by an input-side angular contact ball bearing 6 and an output-side angular contact ball bearing 7. The carrier section 5 comprises a base section 5a and an end plate section 5b. The base section 5a and the end plate section 5b are fixed together by bolts 5c. In other words, the base section 5a and the end plate section 5b can be separated by removing the bolts 5c.

[0053] Furthermore, as shown in Figure 2, the base portion 5a contacts the back surface of the inner ring 7b of the output-side angular contact ball bearing 7 from the output side. Also, the end plate portion 5b contacts the back surface of the inner ring 6b of the input-side angular contact ball bearing 6 from the input side. Therefore, by adjusting the amount of screwing in the bolt 5c in the direction along the central axis Lc, the preload applied to the input-side angular contact ball bearing 6 and the preload applied to the output-side angular contact ball bearing 7 can be adjusted.

[0054] The input-side angular contact ball bearing 6 and the output-side angular contact ball bearing 7 are positioned between the case 2 and the carrier section 5, supporting the carrier section 5 so that it can rotate freely relative to the case 2. The input-side angular contact ball bearing 6 is positioned on the input side of the output-side angular contact ball bearing 7. The central axes of these input-side angular contact ball bearing 6 and output-side angular contact ball bearing 7 coincide with the central axis Lc of the reduction gear 1. In other words, the central axis Lc is also the central axis of the input-side angular contact ball bearing 6 and the output-side angular contact ball bearing 7.

[0055] The input-side angular contact ball bearing 6 comprises an outer ring 6a, an inner ring 6b, and a plurality of rolling elements 6c. The outer circumferential surface of the outer ring 6a is in contact with the inner circumferential surface of the main body portion 21 of the case 2. More specifically, the outer circumferential surface of the outer ring 6a of the input-side angular contact ball bearing 6 is in contact with the inner circumferential surface of the mounting portion 23. The outer circumferential surface of the outer ring 6a is pressed firmly against the inner circumferential surface of the main body portion 21. This prevents the outer circumferential surface of the outer ring 6a from sliding against the inner circumferential surface of the main body portion 21. The inner circumferential surface of the inner ring 6b is in contact with the carrier portion 5. The inner circumferential surface of the inner ring 6b is pressed firmly against the carrier portion 5. This prevents the inner circumferential surface of the inner ring 6b from sliding against the outer circumferential surface of the carrier portion 5. The inner ring 6b may be integrated with the carrier portion 5. Each of the plurality of rolling elements 6c is a sphere and is positioned between the outer ring 6a and the inner ring 6b. These rolling elements 6c allow the inner ring 6b to rotate circumferentially around the central axis Lc relative to the outer ring 6a.

[0056] The input-side angular contact ball bearing 6 is positioned such that the back of the outer ring 6a faces the output side and the front of the outer ring 6a faces the input side. In other words, the input-side angular contact ball bearing 6 is positioned such that the back of the inner ring 6b faces the input side and the front of the inner ring 6b faces the output side. As shown in Figure 2, the back of the outer ring 6a is in contact with the case 2. Also, the back of the inner ring 6b is in contact with the carrier portion 5. In other words, the input-side angular contact ball bearing 6 is sandwiched between the case 2 and the carrier portion 5 in the direction along the central axis Lc.

[0057] The output-side angular contact ball bearing 7 comprises an outer ring 7a, an inner ring 7b, and a plurality of rolling elements 7c. The outer circumferential surface of the outer ring 7a is in contact with the inner circumferential surface of the main body portion 21 of the case 2. The outer circumferential surface of the outer ring 7a is pressed firmly against the inner circumferential surface of the main body portion 21. This prevents the outer circumferential surface of the outer ring 7a from sliding against the inner circumferential surface of the main body portion 21. The inner circumferential surface of the inner ring 7b is in contact with the carrier portion 5. The inner circumferential surface of the inner ring 7b is pressed firmly against the carrier portion 5. This prevents the inner circumferential surface of the inner ring 7b from sliding against the outer circumferential surface of the carrier portion 5. The inner ring 7b may be integrated with the carrier portion 5. Each of the plurality of rolling elements 7c is a sphere and is positioned between the outer ring 7a and the inner ring 7b. These rolling elements 7c allow the inner ring 7b to rotate circumferentially around the central axis Lc relative to the outer ring 7a.

[0058] The output-side angular contact ball bearing 7 is positioned such that the back of the outer ring 7a faces the input side and the front of the outer ring 7a faces the output side. In other words, the output-side angular contact ball bearing 7 is positioned such that the back of the inner ring 7b faces the output side and the front of the inner ring 7b faces the input side. As shown in Figure 2, the back of the outer ring 7a is in contact with the case 2. Also, the back of the inner ring 7b is in contact with the carrier portion 5. In other words, the output-side angular contact ball bearing 7 is sandwiched between the case 2 and the carrier portion 5 in the direction along the central axis Lc.

[0059] Multiple crankshafts 8 are arranged within the case 2 at equal intervals in the circumferential direction with respect to the central axis Lc (see Figure 4). Each crankshaft 8 is supported by a pair of crank bearings 12 and 13 so as to be rotatable around its axis relative to the carrier portion 5. Each crankshaft 8 has a shaft body 8c and a first eccentric portion 8a and a second eccentric portion 8b integrally formed on the shaft body 8c.

[0060] Each crankshaft 8 has a mating portion 8d at its input end in the direction along its central axis Lc, to which a transmission gear 11 is attached. Note that the reduction gear 1 of this embodiment is not limited to the example shown in Figure 2; a mating portion may be placed at the output end of the crankshaft 8, and the transmission gear 11 may be attached to the output mating portion.

[0061] Each first oscillating gear 9 is located inside the case 2 and is attached to the first eccentric portion 8a of the crankshaft 8 via a first roller bearing 14. When the crankshaft 8 rotates and the first eccentric portion 8a rotates eccentrically, each first oscillating gear 9 rotates in conjunction with this eccentric rotation, meshing with the internal tooth pin 4.

[0062] The second oscillating gear 10 is located inside the case 2 and is attached to the second eccentric portion 8b of the crankshaft 8 via a second roller bearing 15. Each second oscillating gear 10 oscillates in conjunction with the eccentric rotation of the crankshaft 8 and the second eccentric portion 8b, while meshing with the internal tooth pin 4.

[0063] Each transmission gear 11 transmits the rotation of the input gear 302 of the servo motor 300 to the crankshaft 8. Each transmission gear 11 is fixed to the mating portion 8d of the crankshaft 8. Each transmission gear 11 rotates integrally with the crankshaft 8 around the same axis of rotation as the crankshaft 8. Each transmission gear 11 has external teeth 11a that mesh with the input gear 302.

[0064] Next, with reference to Figure 3, the positional relationship between the input-side corner C1 and the input-side angular contact ball bearing 6 will be explained.

[0065] The line of action L1 shown in Figure 3 is a straight line passing through the contact point between the rolling element 6c and the outer ring 6a, and the contact point between the rolling element 6c and the inner ring 6b, in the input-side angular contact ball bearing 6. In this embodiment, since the back surface of the outer ring 6a of the input-side angular contact ball bearing 6 is located on the output side and the front surface of the outer ring 6a is located on the input side, the line of action L1 is inclined with respect to the central axis Lc, as shown in Figure 3, so that it approaches the central axis Lc as it approaches the tip of the mounting portion 23 in the direction along the central axis Lc.

[0066] When a preload is applied to the input-side angular contact ball bearing 6, this preload can be represented by a vector that coincides with the line of action L1 and originates from the center of the rolling element 6c, as shown in Figure 3. In this embodiment, this vector is called the preload vector V. That is, the preload vector V originates from the center of the rolling element 6c, coincides with the line of action L1, and extends radially outward from the central axis Lc. In Case 2, the part of the input-side angular contact ball bearing 6 that receives a strong preload is the part located on the line of action L1 of the input-side angular contact ball bearing 6. In the reducer 1 of this embodiment, the input-side corner C1 is located on the tip side of the mounting part 23, relative to the position P where the line of action L1 of the input-side angular contact ball bearing 6 intersects with the outer circumferential surface of the main body 21.

[0067] Therefore, the input-side end face 22a of the flange portion 22 is positioned closer to the tip of the mounting portion 23 in the direction along the central axis Lc than the position P where the line of action L1 of the input-side angular contact ball bearing 6 intersects with the outer circumferential surface of the main body portion 21. The output-side end face 22b of the flange portion 22 is positioned closer to the arm 500 in the direction along the central axis Lc than the position P where the line of action L1 of the input-side angular contact ball bearing 6 intersects with the outer circumferential surface of the main body portion 21. Consequently, the line of action L1 of the input-side angular contact ball bearing passes through the interior of the flange portion 22.

[0068] The flange portion 22 is formed by protruding from the cylindrical main body portion 21 in a direction intersecting the central axis Lc. Therefore, the portion of the case 2 where the flange portion 22 is provided has a larger thickness dimension in the direction intersecting the central axis Lc of the main body portion 21 and is a more rigid portion compared to the portion of the case 2 where the flange portion 22 is not provided. In other words, the line of action L1 of the input-side angular contact ball bearing 6 passes through the rigid portion of the case 2. Therefore, the preload acting on the input-side angular contact ball bearing 6 can be received by the rigid portion of the case 2, and deformation of the mounting portion 23 due to the preload can be suppressed.

[0069] [Operation and Effects of Speed ​​Reducers] The gearbox 1 of this embodiment comprises a case 2, a carrier section 5, and an input-side angular contact ball bearing 6. The input-side angular contact ball bearing 6 is positioned between the case 2 and the carrier section 5, and rotatably supports the carrier section 5 relative to the case 2. The case 2 also has a main body section 21 and a flange section 22. The main body section 21 houses the carrier section 5 and the input-side angular contact ball bearing 6 inside, and the input-side angular contact ball bearing 6 is in contact with the inner circumferential surface of the main body section 21, and is formed in a cylindrical shape. The flange section 22 protrudes from the main body section 21 in a direction intersecting the direction along the central axis Lc. The main body section 21 also has a mounting section 23 that extends from the flange section 22 in a direction along the axis beyond the outer ring 6a of the input-side angular contact ball bearing 6 and can be attached to the motor bracket 200. Furthermore, the input-side corner C1 between the flange portion 22 and the mounting portion 23 is positioned on the tip side of the mounting portion 23, relative to the position P where the line of action L1 of the input-side angular contact ball bearing 6 intersects with the outer circumferential surface of the main body portion 21.

[0070] As described above, the reduction gear 1 of this embodiment can suppress deformation of the case 2 due to the preload applied to the input-side angular contact ball bearing 6. Therefore, with the reduction gear 1, even if the mounting portion 23 provided on the case 2 is formed to protrude from the surrounding area, deformation of the mounting portion 23 can be suppressed.

[0071] Furthermore, in the gearbox 1 of this embodiment, the case 2 has a recess 23c formed by connecting to the input-side corner C1 and recessing a part of the case 2. By providing such a recess 23c, the formation of the case 2 can be made easier. By providing the recess 23c, the thickness dimension of the part of the case 2 with the recess 23c becomes smaller than when the recess 23c is not provided. On the other hand, in the gearbox 1 of this embodiment, since the line of action L1 of the input-side angular contact ball bearing 6 does not pass through the recess 23c, the preload applied to the input-side angular contact ball bearing 6 can be suppressed from acting strongly on the part of the case 2 with the recess 23c. Therefore, according to the gearbox 1 of this embodiment, the case 2 can be provided with a recess 23c, and deformation of the mounting part 23 can be suppressed. Note that the recess 23c is not required.

[0072] Furthermore, in the gearbox 1 of this embodiment, the case 2 has a groove 23b formed on the outer circumferential surface of the mounting portion 23 along the circumferential direction centered on the central axis of the input-side angular contact ball bearing 6. By providing such a groove 23b, the O-ring 700 can be installed. By providing the groove 23b, the thickness dimension of the part of the case 2 with the groove 23b becomes smaller than when the groove 23b is not provided. On the other hand, in the gearbox 1 of this embodiment, since the line of action L1 of the input-side angular contact ball bearing 6 does not pass through the groove 23b, the preload applied to the input-side angular contact ball bearing 6 can be suppressed from acting strongly on the part of the case 2 with the groove 23b. Therefore, according to the gearbox 1 of this embodiment, the case 2 can be provided with a groove 23b, and deformation of the mounting portion 23 can be suppressed. Note that the groove 23b is not required.

[0073] Furthermore, in the gearbox 1 of this embodiment, the line of action L1 of the input-side angular contact ball bearing 6 is inclined with respect to the central axis Lc such that it approaches the central axis Lc as it approaches the tip of the mounting portion 23 in the direction along the central axis Lc. As a result, the position P where the line of action L1 intersects with the circumferential surface of the main body portion 21 is located on the output side of the input-side angular contact ball bearing 6 in the direction along the central axis Lc. Therefore, the length dimension of the flange portion 22 in the direction along the central axis Lc, which is necessary to position the input-side corner portion C1 at a position closer to the tip of the mounting portion 23 than position P, can be suppressed.

[0074] [Examples] For example, in the gearbox 1 of the above embodiment, the inner diameter of the main body 21 is 60 mm or more and less than 200 mm, the wall thickness of the mounting portion 23 is 3 mm or more and 10 mm or less, the outer diameter of the input-side angular contact ball bearing 6 when removed from inside the main body 21 is larger than the inner diameter of the main body 21 by a range of 5 μm or more and 50 μm or less, and the preload acting on the input-side angular contact ball bearing 6 housed inside the main body 21 can be 1000 N or more and 50000 N or less.

[0075] Here, the inner diameter dimension of the main body 21 is the diameter D1 of the internal space of the main body 21 at the position where the input-side angular contact ball bearing 6 is installed (see Figure 2). The wall thickness dimension of the mounting portion 23 is the thickness dimension D2 of the mounting portion 23 in the radial direction centered on the central axis Lc (see Figure 3). Note that the thickness dimension D2 is the value at a position where the recess 23c and groove 23b are not provided. The outer diameter dimension of the input-side angular contact ball bearing 6 is the diameter D3 of the circle traced by the outer circumferential surface of the outer ring 6a of the input-side angular contact ball bearing 6 (see Figure 2). Note that in Figure 2, since the input-side angular contact ball bearing 6 is housed inside the main body 21, the diameter D1 of the internal space of the main body 21 and the diameter D3 of the circle traced by the outer circumferential surface of the outer ring 6a of the input-side angular contact ball bearing 6 coincide.

[0076] Furthermore, in the gearbox 1 of the above embodiment, the inner diameter of the main body 21 is 200 mm or more and less than 290 mm, the wall thickness of the mounting portion 23 is 7 mm or more and 18 mm or less, the outer diameter of the input-side angular contact ball bearing 6 when removed from inside the main body 21 is larger than the inner diameter of the main body 21 by a range of 5 μm or more and 70 μm or less, and the preload acting on the input-side angular contact ball bearing 6 housed inside the main body 21 can be 15,000 N or more and 80,000 N or less.

[0077] Furthermore, in the gearbox 1 of the above embodiment, the inner diameter of the main body 21 is 290 mm or more and less than 390 mm, the wall thickness of the mounting portion 23 is 14 mm or more and 28 mm or less, the outer diameter of the input-side angular contact ball bearing 6 when removed from inside the main body 21 is larger than the inner diameter of the main body 21 by a range of 15 μm or more and 70 μm or less, and the preload acting on the input-side angular contact ball bearing 6 housed inside the main body 21 can be 30,000 N or more and 130,000 N or less.

[0078] As a result, by designing the gearbox 1 to the values ​​shown in this embodiment, the deformation of the mounting portion 23 can be kept within the H7 tolerance range of the Japanese Industrial Standards. Therefore, it becomes possible to securely attach the gearbox 1 to the motor bracket 200.

[0079] (Second Embodiment) Next, the second embodiment will be described with reference to Figure 5. Figure 5 is a partially enlarged view showing the schematic configuration of the gearbox 1A of the second embodiment. Components identical to those in the first embodiment will be denoted by the same reference numerals. Furthermore, in the description of the second embodiment, the same names as in the first embodiment may be used, and explanations may be omitted.

[0080] As shown in Figure 5, the preload vector V can be decomposed into a component Va along the central axis of the input-side angular contact ball bearing 6 and a component Vb along the line L2 perpendicular to the central axis Lc. Component Vb starts from the center of the rolling element 6c and extends radially through the input-side angular contact ball bearing 6, causing deformation of the mounting portion 23.

[0081] As shown in Figure 5, in this embodiment, the input-side corner C1 is positioned on the tip side of the mounting portion 23 from the position P1 where line L2 and the outer circumferential surface of the main body portion 21 intersect. In this embodiment of the gearbox 1A, the component Vb that causes deformation of the mounting portion 23 is directed toward the flange portion 22. In other words, in this embodiment of the gearbox 1A, the component Vb that causes deformation of the mounting portion 23 among the components included in the preload load vector V can be received by a part of the case 2 with high rigidity. Therefore, deformation of the case 2 due to the preload load vector V can be further suppressed.

[0082] Furthermore, the gearbox 1A of this embodiment, like the gearbox 1 of the first embodiment described above, can suppress deformation of the mounting portion 23 even if a recess 23c or groove 23b is provided.

[0083] Furthermore, in the gearbox 1A of this embodiment, the inner diameter of the main body 21 is 60 mm or more and less than 200 mm, the wall thickness of the mounting portion 23 is 3 mm or more and 10 mm or less, the outer diameter of the input-side angular contact ball bearing 6 when removed from inside the main body 21 is larger than the inner diameter of the main body 21 by a range of 5 μm or more and 50 μm or less, and the preload acting on the input-side angular contact ball bearing 6 housed inside the main body 21 can be 1000 N or more and 50000 N or less. As a result, the deformation of the mounting portion 23 can be kept within the Japanese Industrial Standards h7 tolerance range.

[0084] Furthermore, in the gearbox 1A of this embodiment, the inner diameter of the main body 21 is 200 mm or more and less than 290 mm, the wall thickness of the mounting portion 23 is 7 mm or more and 18 mm or less, the outer diameter of the input-side angular contact ball bearing 6 when removed from inside the main body 21 is larger than the inner diameter of the main body 21 by a range of 5 μm or more and 70 μm or less, and the preload acting on the input-side angular contact ball bearing 6 housed inside the main body 21 can be 15,000 N or more and 80,000 N or less. As a result, the deformation of the mounting portion 23 can be kept within the Japanese Industrial Standards h7 tolerance range.

[0085] Furthermore, in the gearbox 1A of this embodiment, the inner diameter of the main body 21 is 290 mm or more and less than 390 mm, the wall thickness of the mounting portion 23 is 14 mm or more and 28 mm or less, the outer diameter of the input-side angular contact ball bearing 6 when removed from inside the main body 21 is 15 μm or more and 70 μm or less than the inner diameter of the main body 21, and the preload acting on the input-side angular contact ball bearing 6 housed inside the main body 21 can be 30,000 N or more and 130,000 N or less. As a result, the deformation of the mounting portion 23 can be kept within the Japanese Industrial Standards h7 tolerance range.

[0086] (Third embodiment) Next, a sixth embodiment will be described with reference to Figure 6. Figure 6 is a schematic diagram of the cooperative robot 100. In this embodiment, the vertical and horizontal directions of the cooperative robot 100 refer to the vertical and horizontal directions when the cooperative robot 100 is placed on the mounting surface F.

[0087] As shown in Figure 1, the collaborative robot 100 (an example of the robot in the claim) comprises a base portion 101 (an example of the first or second member in the claim) placed on the installation surface F, a rotating head 102 (an example of the first or second member in the claim) provided on the base portion 101, and an arm unit 103 (an example of the first or second member in the claim) rotatably mounted on the upper part of the rotating head 102 (an example of the first or second member in the claim). For example, the arm unit 103 includes a base unit 101, a rotating head 102, and reduction gears (first reduction gear 10A, second reduction gear 10B, third reduction gear 10C) assembled to the joints (first joint 106a, second joint 106b, third joint 106c) of the arm unit 103, servo motors (first servo motor 107, second servo motor 108, third servo motor 109) as a drive source, and an end effector 110 attached to the arm unit 103.

[0088] The rotating head 102 is rotatably connected to the base portion 101 around a first rotation axis LA. This connected portion is the first joint portion 106a, and the first reduction gear 10A and the first servo motor 107 are assembled to the first joint portion 106a. The first rotation axis LA coincides, for example, with the vertical direction. The rotation of the first servo motor 107 is transmitted to the rotating head 102 via the first reduction gear 10A. As a result, the rotating head 102 is rotationally driven around the first rotation axis LA relative to the base portion 101.

[0089] The arm unit 103 consists of, for example, two arms (first arm 104 and second arm 105) that are long in one direction. One end of the first arm 104 is rotatably connected to the upper part of the rotating head 102 around a second rotation axis LB. This connected part is the second joint 106b, and the second reduction gear 10B and the second servo motor 108 are assembled to the second joint 106b. The second rotation axis LB coincides with, for example, the horizontal direction. The rotation of the second servo motor 108 is transmitted to the first arm 104 via the second reduction gear 10B. As a result, the first arm 104 is rotationally driven around the second rotation axis LB relative to the rotating head 102. For example, the first arm 104 is driven to swing in the front-rear direction relative to the base 101.

[0090] One end of the second arm 105 is rotatably connected to the other end of the first arm 104 around the third rotation axis LC. This connected portion is the third joint 106c, to which the third reduction gear 10C and the third servo motor 109 are assembled. The third rotation axis LC coincides, for example, with the horizontal direction. The rotation of the third servo motor 109 is transmitted to the second arm 105 via the third reduction gear 10C. As a result, the second arm 105 is rotationally driven relative to the first arm 104 around the third rotation axis LC. For example, the second arm 105 is driven to swing up and down relative to the first arm 104.

[0091] The end effector 110 is attached to the other end of the second arm 105. The end effector 110 is driven in three dimensions by driving the rotating head 102, the first arm 104, and the second arm 105.

[0092] In this embodiment, the cooperative robot 100 has a first reducer 10A, a second reducer 10B, and a third reducer 10C, each of which is either the reducer 1 of the first embodiment or the reducer 1A of the second embodiment. Therefore, in this embodiment, deformation of the mounting portion 23 of the first reducer 10A, the second reducer 10B, and the third reducer 10C is suppressed. Note that one or two of the first reducer 10A, the second reducer 10B, and the third reducer 10C may be either the reducer 1 of the first embodiment or the reducer 1A of the second embodiment. The reducers (first reducer 10A, second reducer 10B, third reducer 10C) can be mounted with, for example, servo motors (first servo motor 107, second servo motor 108, third servo motor 109) as mating members. Furthermore, the gearboxes (first gearbox 10A, second gearbox 10B, third gearbox 10C) may be attached to mating members such as motor brackets (not shown).

[0093] The present invention is not limited to the embodiments described above, but includes various modifications to the embodiments described above without departing from the spirit of the invention. For example, the above embodiment described a case in which a collaborative robot 100 is equipped with three reduction gears (first reduction gear 10A, second reduction gear 10B, and third reduction gear 10C). However, it is not limited to this. The configuration of the above embodiment can be adopted for various robots having two members (first member and second member), with a reduction gear provided between the two members, and the second member rotating relative to the first member.

[0094] Furthermore, in the above-described embodiment, a speed reducer was explained as an example of a rotating mechanism. However, the rotating mechanism is not limited to this. The configuration of the above embodiment can be applied to various rotating mechanisms comprising a case, a rotating body, and a bearing positioned between the case and the rotating body to rotatably support the rotating body relative to the case. In other words, the bearing is not limited to an angular contact ball bearing. For example, other bearings such as tapered roller bearings can be used as the bearing.

[0095] Furthermore, in the above-described embodiment, the mounting portion 23 provided on the case 2 was formed to protrude from the flange portion 22 to a distance from the input-side angular contact ball bearing 6. However, the mounting portion 23 does not need to extend to a distance from the input-side angular contact ball bearing 6.

[0096] Among the embodiments disclosed herein, those composed of multiple objects may be integrated, and conversely, those composed of a single object may be divided into multiple objects. Whether or not they are integrated, the invention can be constructed in a way that achieves its objective. [Explanation of Symbols]

[0097] 1, 1A, 10A, 10B, 10C... Gear reducers (rotating mechanisms) 2... Cases 5... Carrier section (rotating body) 6... Input side angular contact ball bearing (angular contact ball bearing, bearing) 6a... Outer ring 6c... Rolling element 21...Main body 21a... recess 21b... Pin groove 22... Guard part 23... Mounting part 23b……Groove 23c... recess 100... Collaborative robot (robot) 101... Base section (first member, second member) 102... Rotating head (first component, second component) 103... Arm unit (first component, second component) 104... First arm (first member, second member) 105... Second arm (first member, second member) 107...First servo motor (mating component) 108... Second servo motor (mating component) 109...Third servo motor (mating component) 200... Motor bracket (mating component) C1... Input side corner (corner) L1……line of action L2……line Lc……Central axis (axis)

Claims

1. The case and, A solid of rotation and A bearing positioned between the case and the rotating body, which rotatably supports the rotating body relative to the case, Equipped with, The aforementioned case is, A cylindrical body portion that houses the rotating body and the bearing inside and has the bearing in contact with its inner circumferential surface, A flange portion is arranged in a direction intersecting the direction along the axis of the main body portion, It has, The main body portion has a mounting portion that is provided in a direction along the axis from the flange portion and can be attached to a mating member, The corner between the flange and the mounting portion is positioned on the tip side of the mounting portion, relative to the point where the line of action of the bearing intersects with the outer circumferential surface of the main body. The line of action of the bearing intersects the connection point between the flange and the main body and the outer circumferential surface of the flange. The outer circumferential surface has a main body surface parallel to the axis and a corner surface connecting the main body surface and the end surface of the flange portion that intersects the axis. The line of action passes through the connection between the main body surface and the corner surface. Rotating mechanism.

2. The rotating mechanism according to claim 1, wherein the main body portion is provided extending from the flange portion in a direction along the axis, more than the outer ring of the bearing.

3. The bearing is an angular contact ball bearing, The rotation mechanism according to claim 1 or 2, wherein the corner portion is positioned on the tip side of the mounting portion from the position where a line perpendicular to the central axis of the angular contact ball bearing and passing through the center of the rolling element intersects with the outer circumferential surface of the main body portion.

4. The rotating mechanism according to claim 1 or 2, wherein the case has a recess formed by connecting to the corner and recessing a part of the case.

5. The rotation mechanism according to claim 1 or 2, wherein the case has a groove formed on the outer circumferential surface of the mounting portion along the circumferential direction centered on the central axis of the bearing.

6. The rotation mechanism according to claim 1 or 2, wherein the line of action is inclined with respect to the axis such that it approaches the axis as it approaches the tip of the mounting portion with respect to the direction along the axis of the main body portion.

7. The inner diameter of the main body is 60 mm or more and less than 200 mm. The thickness dimension of the mounting portion is 3 mm or more and 10 mm or less. The outer diameter of the angular contact ball bearing when removed from the main body is larger than the inner diameter of the main body by a range of 5 μm or more and 50 μm or less. The preload acting on the angular contact ball bearing housed inside the main body is between 1,000 N and 50,000 N. The rotating mechanism according to claim 3.

8. The inner diameter of the main body is 200 mm or more and less than 290 mm. The thickness dimension of the mounting portion is 7 mm or more and 18 mm or less. The outer diameter of the angular contact ball bearing when removed from the main body is larger than the inner diameter of the main body by a range of 5 μm or more and 70 μm or less. The preload acting on the angular contact ball bearing housed inside the main body is 15,000 N or more and 80,000 N or less. The rotating mechanism according to claim 3.

9. The inner diameter of the main body is 290 mm or more and less than 390 mm. The thickness dimension of the mounting portion is 14 mm or more and 28 mm or less. The outer diameter of the angular contact ball bearing when removed from the main body is larger than the inner diameter of the main body by a range of 15 μm or more and 70 μm or less. The preload acting on the angular contact ball bearing housed inside the main body is between 30,000 N and 130,000 N. The rotating mechanism according to claim 3.

10. The case and, A solid of rotation and An angular contact ball bearing is positioned between the case and the rotating body, and rotatably supports the rotating body relative to the case. Equipped with, The aforementioned case is, A cylindrical body portion that houses the rotating body and the angular contact ball bearing inside, and in which the angular contact ball bearing is in contact with the inner circumferential surface, It has a flange portion that protrudes from the main body portion in a direction intersecting the direction along the axis of the main body portion, The main body portion is provided extending from the flange portion in a direction along the axis beyond the outer ring of the angular contact ball bearing and has a mounting portion that can be attached to a mating member. The line of action of the angular contact ball bearing is inclined with respect to the axis, such that it approaches the axis as it approaches the tip of the mounting portion in the direction along the axis of the main body, The corner between the flange and the mounting portion is positioned on the tip side of the mounting portion, at a point where a line perpendicular to the central axis of the angular contact ball bearing and passing through the center of the rolling element intersects with the outer circumferential surface of the main body. The aforementioned case is, A recess formed by connecting to the aforementioned corner and recessing a part of the case, A groove is formed on the outer circumferential surface of the mounting portion, along the circumferential direction centered on the central axis of the angular contact ball bearing, It further possesses, The line of action of the angular contact ball bearing intersects the connection point between the flange and the main body and the outer circumferential surface of the flange. The outer circumferential surface has a main body surface parallel to the axis and a corner surface connecting the main body surface and the end surface of the flange portion that intersects the axis. The line of action passes through the connection between the main body surface and the corner surface. The inner diameter of the main body is 60 mm or more and less than 200 mm. The thickness dimension of the mounting portion is 3 mm or more and 10 mm or less. The outer diameter of the angular contact ball bearing when removed from the main body is larger than the inner diameter of the main body by a range of 5 μm or more and 50 μm or less. The preload acting on the angular contact ball bearing housed inside the main body is between 1,000 N and 50,000 N. Rotating mechanism.

11. The case and, A solid of rotation and An angular contact ball bearing is positioned between the case and the rotating body, and rotatably supports the rotating body relative to the case. Equipped with, The aforementioned case is, A cylindrical body portion that houses the rotating body and the angular contact ball bearing inside, and in which the angular contact ball bearing is in contact with the inner circumferential surface, It has a flange portion that protrudes from the main body portion in a direction intersecting the direction along the axis of the main body portion, The main body portion is provided extending from the flange portion in a direction along the axis beyond the outer ring of the angular contact ball bearing and has a mounting portion that can be attached to a mating member. The line of action of the angular contact ball bearing is inclined with respect to the axis, such that it approaches the axis as it approaches the tip of the mounting portion in the direction along the axis of the main body, The corner between the flange and the mounting portion is positioned on the tip side of the mounting portion, at a point where a line perpendicular to the central axis of the angular contact ball bearing and passing through the center of the rolling element intersects with the outer circumferential surface of the main body. The aforementioned case is, A recess formed by connecting to the aforementioned corner and recessing a part of the case, A groove is formed on the outer circumferential surface of the mounting portion, along the circumferential direction centered on the central axis of the angular contact ball bearing, It further possesses, The line of action of the angular contact ball bearing intersects the connection point between the flange and the main body and the outer circumferential surface of the flange. The outer circumferential surface has a main body surface parallel to the axis and a corner surface connecting the main body surface and the end surface of the flange portion that intersects the axis. The line of action passes through the connection between the main body surface and the corner surface. The inner diameter of the main body is 200 mm or more and less than 290 mm. The thickness dimension of the mounting portion is 7 mm or more and 18 mm or less. The outer diameter of the angular contact ball bearing when removed from the main body is larger than the inner diameter of the main body by a range of 5 μm or more and 70 μm or less. The preload acting on the angular contact ball bearing housed inside the main body is 15,000 N or more and 80,000 N or less. Rotating mechanism.

12. The case and, A solid of rotation and An angular contact ball bearing is positioned between the case and the rotating body, and rotatably supports the rotating body relative to the case. Equipped with, The aforementioned case is, A cylindrical body portion that houses the rotating body and the angular contact ball bearing inside, and in which the angular contact ball bearing is in contact with the inner circumferential surface, It has a flange portion that protrudes from the main body portion in a direction intersecting the direction along the axis of the main body portion, The main body portion is provided extending from the flange portion in a direction along the axis beyond the outer ring of the angular contact ball bearing and has a mounting portion that can be attached to a mating member. The line of action of the angular contact ball bearing is inclined with respect to the axis, such that it approaches the axis as it approaches the tip of the mounting portion in the direction along the axis of the main body, The corner between the flange and the mounting portion is positioned on the tip side of the mounting portion, at a point where a line perpendicular to the central axis of the angular contact ball bearing and passing through the center of the rolling element intersects with the outer circumferential surface of the main body. The aforementioned case is, A recess formed by connecting to the aforementioned corner and recessing a part of the case, A groove is formed on the outer circumferential surface of the mounting portion, along the circumferential direction centered on the central axis of the angular contact ball bearing, It further possesses, The line of action of the angular contact ball bearing intersects the connection point between the flange and the main body and the outer circumferential surface of the flange. The outer circumferential surface has a main body surface parallel to the axis and a corner surface connecting the main body surface and the end surface of the flange portion that intersects the axis. The line of action passes through the connection between the main body surface and the corner surface. The inner diameter of the main body is 290 mm or more and less than 390 mm. The thickness dimension of the mounting portion is 14 mm or more and 28 mm or less. The outer diameter of the angular contact ball bearing when removed from the main body is larger than the inner diameter of the main body by a range of 15 μm or more and 70 μm or less. The preload acting on the angular contact ball bearing housed inside the main body is between 30,000 N and 130,000 N. Rotating mechanism.

13. First member and The second member and A rotating mechanism provided between the first member and the second member, which connects the second member to the first member for rotation, Equipped with, The aforementioned rotating mechanism is The case and, A solid of rotation and A bearing positioned between the case and the rotating body, which rotatably supports the rotating body relative to the case, Equipped with, The aforementioned case is, A cylindrical body portion that houses the rotating body and the bearing inside and has the bearing in contact with its inner circumferential surface, A flange portion is arranged in a direction intersecting the direction along the axis of the main body portion, It has, The main body portion has a mounting portion that is provided in a direction along the axis from the flange portion and can be attached to a mating member, The corner between the flange and the mounting portion is positioned on the tip side of the mounting portion, relative to the point where the line of action of the bearing intersects with the outer circumferential surface of the main body. The line of action of the bearing intersects the connection point between the flange and the main body and the outer circumferential surface of the flange. The outer circumferential surface has a main body surface parallel to the axis and a corner surface connecting the main body surface and the end surface of the flange portion that intersects the axis. The line of action passes through the connection between the main body surface and the corner surface. robot.

14. Three crankshafts rotatably supported with respect to the rotating body, A rocking gear rotatably supported on the eccentric part of the crankshaft, An internal tooth is provided on the inner circumferential surface of the case and meshes with the external tooth of the oscillating gear, Equipped with, The rotating mechanism according to claim 1 or 2.

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