Rotary mechanism and robot

Abstract

This invention provides a rotating mechanism and a robot. In the rotating mechanism of this invention, the housing (2) has: a cylindrical main body (21) that houses a gear carrier (5) and an input-side angular contact ball bearing (6) inside, and the input-side angular contact ball bearing contacts the inner circumferential surface of the main body; and a flange (22) that protrudes from the main body in a direction intersecting the direction along the axis of the main body. The main body has a mounting portion (23) that extends from the flange (22) in a direction along the axis relative to the outer ring (6a) of the input-side angular contact ball bearing, and can be mounted on a component. The input-side angular portion (C1) between the flange (22) and the mounting portion (23) is positioned closer to the top end of the mounting portion (23) than the position where the line of action (L1) of the input-side angular contact ball bearing intersects the outer circumferential surface of the main body.

Description

Technical Field

[0001] This invention relates to rotating mechanisms and robots. Background Technology

[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 holds the gear carrier in a rotatable position relative to the outer cylinder. Patent Document 2 discloses a drive device. The drive device disclosed in Patent Document 2 includes a main bearing disposed between the gear carrier and the housing.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-227333

[0006] Patent Document 2: Japanese Patent Application Publication No. 2020-133761 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] The eccentric oscillating gear device disclosed in Patent Document 1 and the drive device disclosed in Patent Document 2 both utilize angular contact ball bearings as the main bearings for supporting the rotating body to rotate freely. For example, a rotating mechanism that uses such a main bearing to support the rotating body to rotate freely includes a housing for housing the main bearing. A portion of such a housing is used as a mounting part for mounting to components such as motors or robots. However, the mounting part may deform due to the preload applied to the main bearing. If the mounting part deforms and deviates from the specified dimensional tolerances, a problem arises where the rotating mechanism cannot be mounted to the component.

[0009] The present invention was made in view of the above-mentioned problems, and provides a rotating mechanism capable of suppressing deformation of the mounting portion that can be mounted on an object component, and a robot having the rotating mechanism.

[0010] Solution for solving the problem

[0011] (1) The rotating mechanism of the first aspect of the present invention comprises: a housing; a rotating body; and a bearing located between the housing and the rotating body, supporting the rotating body so as to be rotatable relative to the housing. The housing has: a cylindrical main body portion that houses the rotating body and the bearing, and the bearing contacts the inner peripheral surface of the main body portion; and a flange portion disposed 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 disposed from the flange portion in a direction along the axis, and is capable of being mounted to an object member. The corner portion between the flange portion and the mounting portion is disposed at a position closer to the top end of the mounting portion than the position where the line of action of the bearing intersects the outer peripheral surface of the main body portion.

[0012] The portion of the housing that strongly bears the preload acting on the bearing is located on the bearing's line of action. In the rotating mechanism of the first embodiment of the present invention, the corner between the flange and the mounting portion is positioned at a point shifted from the point where the bearing's line of action intersects the outer peripheral surface of the main body towards the top end of the mounting portion. Therefore, the bearing's line of action passes through the interior of the flange. The flange is positioned so as to protrude from the cylindrical main body in a direction intersecting the axis of the main body. Consequently, compared to the portion of the housing without a flange, the portion of the housing with the flange has a larger thickness and higher rigidity in the direction intersecting the axial direction of the main body. In other words, in the rotating mechanism of the first embodiment of the present invention, the bearing's line of action passes through a portion of the housing with higher rigidity.

[0013] Therefore, the preload acting on the bearing can be borne by the parts of the housing with higher rigidity, and deformation of the housing caused by the preload can be suppressed. Therefore, according to the first aspect of the rotating mechanism of the present invention, even if the mounting portion provided to the housing is formed to protrude relative to the surrounding parts, deformation of the mounting portion can be suppressed.

[0014] (2) In the above structure, the mounting portion may also be provided such that it extends relative to the outer ring of the bearing in a direction along the axis from the flange portion.

[0015] (3) In the above structure, the bearing may also be an angular contact ball bearing. Alternatively, the corner portion may be positioned near the top end of the mounting portion at a location where the line intersects the outer peripheral surface of the main body portion, and the line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element.

[0016] (4) In the above structure, the housing may also have a recess that is connected to the corner, and the recess is formed by partially recessing the housing.

[0017] (5) In the above structure, the housing may also have a groove formed circumferentially on the outer peripheral surface of the mounting portion along the central axis of the bearing.

[0018] (6) In the above structure, the line of action may be inclined relative to the axis in a way that it moves closer to the axis as it moves toward the top of the mounting portion in the direction along the axis of the main body portion.

[0019] (7) In the above structure, the inner diameter of the main body is 60 mm or more and less than 200 mm, the wall thickness of the mounting part is 3 mm or more and less than 10 mm, the outer diameter of the angular contact ball bearing in the state of being taken out from the inside of the main body is 5 μm or more and less than 50 μm larger than the inner diameter of the main body, 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.

[0020] (8) In the above structure, 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 less than 18 mm, the outer diameter of the angular contact ball bearing in the state of being taken out from the inside of the main body is 5 μm or more and less than 70 μm larger than the inner diameter of the main body, and the preload acting on the angular contact ball bearing housed inside the main body is 15000 N or more and less than 80000 N.

[0021] (9) In the above structure, 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 less than 28 mm, the outer diameter of the angular contact ball bearing in the state of being taken out from the inside of the main body is 15 μm or more and less than 70 μm larger than the inner diameter of the main body, 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.

[0022] (10) The rotating mechanism of the second aspect of the present invention comprises: a housing; a rotating body; and an angular contact ball bearing located between the housing and the rotating body, supporting the rotating body so as to be rotatable relative to the housing. The housing has: a cylindrical main body portion that houses the rotating body and the angular contact ball bearing, wherein the angular contact ball bearing contacts the inner peripheral surface of the main body portion; and a flange portion that protrudes from the main body portion in a direction intersecting the axis of the main body portion. The main body portion has a mounting portion that extends from the flange portion relative to the outer ring of the angular contact ball bearing in a direction along the axis, and is capable of being mounted on a workpiece. The line of action of the angular contact ball bearing is inclined relative to the axis of the main body portion in a direction that approaches the top end of the mounting portion as it moves toward the top end of the mounting portion. The corner between the flange portion and the mounting portion is positioned such that it is closer to the top end of the mounting portion than the position where the line intersects the outer peripheral surface of the main body portion, the line being orthogonal to the central axis of the angular contact ball bearing and passing through the center of the rolling element. The housing further comprises: a recess connected to the corner portion, wherein the recess is formed by partially recessing the housing; and a groove formed circumferentially on the outer peripheral surface of the mounting portion centered on the central axis of the angular contact ball bearing. The inner diameter of the main body portion 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 the interior of the main body portion, is 5 μm or more and less than 50 μm larger than the inner diameter of the main body portion. The preload acting on the angular contact ball bearing housed inside the main body portion is 1000 N or more and less than 50000 N.

[0023] The preload acting on an angular contact ball bearing can be considered as a vector extending radially outward from the center of the rolling elements along the line of action toward the bearing. This vector is defined as the preload vector. The preload vector can be decomposed into a component along the central axis of the bearing and a component along a line orthogonal to the central axis. The component along the line orthogonal to the central axis, originating from the center of the rolling elements and extending radially toward the bearing, is the primary cause of deformation of the mounting portion that protrudes relative to the outer ring of the bearing.

[0024] In the rotating mechanism of the second aspect of the present invention, the corner between the flange and the mounting portion is arranged at a position near the top end of the mounting portion where the line intersects with the outer peripheral surface of the main body. This line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element.

[0025] Therefore, the component of the preload vector that is the main cause of deformation of the mounting portion is oriented towards the flange. The flange protrudes from the cylindrical main body in a direction intersecting the axis of the main body. Consequently, compared to the portion of the housing without a flange, the portion of the housing with the flange has a larger thickness and higher rigidity in the direction intersecting the axis of the main body. In other words, in the rotating mechanism of the second aspect of the present invention, the component of the preload vector that is the main cause of deformation of the mounting portion can be borne by the portion of the housing with higher rigidity.

[0026] Therefore, deformation of the housing caused by the preload vector can be suppressed. Thus, according to the second aspect of the rotating mechanism of the present invention, even if the mounting portion provided to the housing is formed to protrude relative to the surrounding parts, deformation of the mounting portion can be suppressed.

[0027] Furthermore, in the rotating mechanism of the second aspect of the present invention, the housing also includes: a recess connected to the corner portion, formed by partially recessing the housing; and a groove formed circumferentially along the central axis of the angular contact ball bearing on the outer peripheral surface of the mounting portion. By providing these recesses and grooves, the main body portion becomes locally thinner compared to the case where these recesses and grooves are not provided. However, in the rotating mechanism of the second aspect of the present invention, the component of the preload vector that is the main cause of deformation of the mounting portion can be borne by utilizing the more rigid portion of the housing; therefore, even with the recesses and grooves provided, deformation of the mounting portion can be suppressed.

[0028] Furthermore, in the rotating mechanism of the second embodiment 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 less than 10 mm. The outer diameter of the angular contact ball bearing in the state of being removed from the interior of the main body is 5 μm or more and less than 50 μm larger than the inner diameter of the main body. The preload acting on the angular contact ball bearing housed inside the main body is 1000 N or more and less than 50000 N.

[0029] This ensures that the deformation of the mounting part is within the h7 tolerance range of the Japanese Industrial Standard.

[0030] (11) The rotating mechanism of the third aspect of the present invention comprises: a housing; a rotating body; and an angular contact ball bearing located between the housing and the rotating body, supporting the rotating body so as to be rotatable relative to the housing. The housing has: a cylindrical main body portion that houses the rotating body and the angular contact ball bearing, wherein the angular contact ball bearing contacts the inner peripheral surface of the main body portion; and a flange portion that protrudes from the main body portion in a direction intersecting the axis of the main body portion. The main body portion has a mounting portion that extends from the flange portion relative to the outer ring of the angular contact ball bearing in a direction along the axis, and is capable of being mounted on a workpiece. The line of action of the angular contact ball bearing is inclined relative to the axis of the main body portion such that it approaches the axis of the mounting portion toward the top end of the mounting portion in a direction along the axis of the main body portion. The corner between the flange portion and the mounting portion is arranged such that it is located closer to the top end of the mounting portion than the position where the line intersects the outer peripheral surface of the main body portion, the line being orthogonal to the central axis of the angular contact ball bearing and passing through the center of the rolling element. The housing further comprises: a recess connected to the corner portion, wherein the recess is formed by partially recessing the housing; and a groove formed circumferentially on the outer peripheral surface of the mounting portion 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 the interior of the main body, is 5 μm or more and less than 70 μm larger than the inner diameter of the main body. The preload acting on the angular contact ball bearing housed inside the main body is 15000 N or more and less than 80000 N.

[0031] In the rotating mechanism of the third aspect of the present invention, the corner between the flange and the mounting portion is positioned near the top end of the mounting portion at a location where a line intersects the outer peripheral surface of the main body. This line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element. Therefore, the component of the preload vector that is the main cause of deformation of the mounting portion is directed towards the flange. The flange protrudes from the cylindrical main body in a direction intersecting the axis along the main body. Consequently, compared to the portion of the housing without a flange, the portion of the housing with the flange has a larger thickness and higher rigidity in the direction intersecting the axial direction of the main body. In other words, in the rotating mechanism of the third aspect of the present invention, the component of the preload vector that is the main cause of deformation of the mounting portion can be borne by the portion of the housing with higher rigidity.

[0032] Therefore, deformation of the housing caused by the preload vector can be suppressed. Thus, according to the third aspect of the rotating mechanism of the present invention, even if the mounting portion provided to the housing is formed to protrude relative to the surrounding parts, deformation of the mounting portion can be suppressed.

[0033] Furthermore, in the rotating mechanism of the third aspect of the present invention, the housing also includes: a recess connected to the corner portion, formed by partially recessing the housing; and a groove formed circumferentially along the central axis of the angular contact ball bearing on the outer peripheral surface of the mounting portion. By providing these recesses and grooves, the main body portion becomes locally thinner compared to the case where these recesses and grooves are not provided. However, in the rotating mechanism of the third aspect of the present invention, the component of the preload vector that is the main cause of deformation of the mounting portion can be borne by utilizing the more rigid portion of the housing; therefore, even with the recesses and grooves provided, deformation of the mounting portion can be suppressed.

[0034] Furthermore, in the rotating mechanism of the third embodiment 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 portion is 7 mm or more and less than 18 mm. The outer diameter of the angular contact ball bearing in the state of being removed from the interior of the main body is 5 μm or more and less than 70 μm larger than the inner diameter of the main body. 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.

[0035] This ensures that the deformation of the mounting part is within the h7 tolerance range of the Japanese Industrial Standard.

[0036] (12) The rotating mechanism of the fourth aspect of the present invention comprises: a housing; a rotating body; and an angular contact ball bearing located between the housing and the rotating body, supporting the rotating body so as to be rotatable relative to the housing. The housing has: a cylindrical main body portion that houses the rotating body and the angular contact ball bearing, wherein the angular contact ball bearing contacts the inner peripheral surface of the main body portion; and a flange portion that protrudes from the main body portion in a direction intersecting the axis of the main body portion. The main body portion has a mounting portion that extends from the flange portion relative to the outer ring of the angular contact ball bearing in a direction along the axis, and is capable of being mounted on a workpiece. The line of action of the angular contact ball bearing is inclined relative to the axis of the main body portion in a direction that approaches the top end of the mounting portion as it moves toward the axis of the main body portion. The corner between the flange portion and the mounting portion is positioned such that it is closer to the top end of the mounting portion than the position where the line intersects the outer peripheral surface of the main body portion, the line being orthogonal to the central axis of the angular contact ball bearing and passing through the center of the rolling element. The housing further comprises: a recess connected to the corner portion, wherein the recess is formed by partially recessing the housing; and a groove formed circumferentially on the outer peripheral surface of the mounting portion 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 the interior of the main body, is 15 μm or more and less than 70 μm larger than the inner diameter of the main body. 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.

[0037] In the rotating mechanism of the fourth aspect of the present invention, the corner between the flange and the mounting portion is positioned near the top end of the mounting portion at a location where a line intersects the outer peripheral surface of the main body. This line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element. Therefore, the component of the preload vector that is the main cause of deformation of the mounting portion is directed towards the flange. The flange protrudes from the cylindrical main body in a direction intersecting the axis along the main body. Consequently, compared to the portion of the housing without a flange, the portion of the housing with the flange has a larger thickness and higher rigidity in the direction intersecting the axial direction of the main body. In other words, in the rotating mechanism of the fourth aspect of the present invention, the component of the preload vector that is the main cause of deformation of the mounting portion can be borne by the portion of the housing with higher rigidity.

[0038] Therefore, deformation of the housing caused by the preload vector can be suppressed. Thus, according to the fourth aspect of the rotating mechanism of the present invention, even if the mounting portion provided to the housing is formed to protrude relative to the surrounding parts, deformation of the mounting portion can be suppressed.

[0039] Furthermore, in the rotating mechanism of the fourth aspect of the present invention, the housing also includes: a recess connected to the corner portion, formed by partially recessing the housing; and a groove formed circumferentially along the central axis of the angular contact ball bearing on the outer peripheral surface of the mounting portion. By providing these recesses and grooves, the main body portion becomes locally thinner compared to the case where these recesses and grooves are not provided. However, in the rotating mechanism of the fourth aspect of the present invention, the component of the preload vector that is the main cause of deformation of the mounting portion can be borne by utilizing the more rigid portion of the housing; therefore, even with the recesses and grooves provided, deformation of the mounting portion can be suppressed.

[0040] Furthermore, in the rotating mechanism of the fourth embodiment 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 portion is 14 mm or more and less than 28 mm. The outer diameter of the angular contact ball bearing in the state of being removed from the interior of the main body is 15 μm or more and less than 70 μm larger than the inner diameter of the main body. 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.

[0041] This ensures that the deformation of the mounting part is within the h7 tolerance range of the Japanese Industrial Standard.

[0042] (13) A robot of the fifth aspect of the present invention comprises: a first member; a second member; and a rotating mechanism disposed between the first member and the second member, connecting the second member to rotate relative to the first member. The rotating mechanism comprises: a housing; a rotating body; and a bearing located between the housing and the rotating body, supporting the rotating body to rotate freely relative to the housing. The housing has: a cylindrical main body portion that houses the rotating body and the bearing, and the bearing contacts the inner peripheral surface of the main body portion; and a flange portion disposed 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 disposed from the flange portion in a direction along the axis, and capable of being mounted to a target member. The corner portion between the flange portion and the mounting portion is disposed at a position closer to the top end of the mounting portion than the position where the line of action of the bearing intersects the outer peripheral surface of the main body portion.

[0043] In the rotating mechanism, the corner between the flange and the mounting portion is positioned near the top end of the mounting portion, closer to the point where the bearing's line of action intersects the outer peripheral surface of the main body. Therefore, the bearing's line of action passes through the interior of the flange. The flange protrudes from the cylindrical main body in a direction intersecting the axis of the main body. Therefore, compared to the portion of the housing without a flange, the portion with the flange has a larger thickness and higher rigidity in the direction intersecting the axial direction of the main body. In other words, in the rotating mechanism, the bearing's line of action passes through the portion of the housing with higher rigidity. Therefore, the preload acting on the bearing can be borne by the portion of the housing with higher rigidity, and deformation of the housing caused by the preload can be suppressed. Therefore, according to the rotating mechanism, even if the mounting portion provided to the housing protrudes relative to the surrounding portions, deformation of the mounting portion can be suppressed. The robot of the fifth aspect of the present invention possesses the above-described rotating mechanism. Therefore, deformation of the mounting portion of the rotating mechanism can be suppressed, and the rotating mechanism can be reliably connected to the first member or the second member.

[0044] The effects of the invention

[0045] The aforementioned rotating mechanism and robot are able to suppress deformation of the mounting portion, which is designed to be mounted relative to the object component. Attached Figure Description

[0046] Figure 1 It is a cross-sectional view showing the general structure of the speed reducer in the first embodiment of the present invention.

[0047] Figure 2 This is a schematic cross-sectional view of the speed reducer according to the first embodiment of the present invention.

[0048] Figure 3 yes Figure 2 Enlarged view of the main parts.

[0049] Figure 4 yes Figure 2 Sectional view IV-IV.

[0050] Figure 5 This is an enlarged view of the main parts of the schematic structure of the speed reducer in the second embodiment of the present invention.

[0051] Figure 6 This is a schematic diagram of the coordination robot in the third embodiment of the present invention.

[0052] Explanation of reference numerals in the attached figures

[0053] 1. 1A, 10A, 10B, 10C, Reducer (rotary mechanism); 2. Housing; 5. Gear frame (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. Flange; 23. Mounting part; 23b. Groove; 23c. Recess; 100. Coordinating robot (robot); 101. Base part (first component, second component); 102. Rotating head ( 103. Arm Unit (1st Component, 2nd Component); 104. First Arm (1st Component, 2nd Component); 105. Second Arm (1st Component, 2nd Component); 107. First Servo Motor (Object Component); 108. Second Servo Motor (Object Component); 109. Third Servo Motor (Object Component); 200. Motor Bracket (Object Component); C1. Input Side Corner (Corner); L1. Line of Action; L2. Line; Lc. Central Axis (Axis). Detailed Implementation

[0054] Hereinafter, the rotating mechanism and robot according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the embodiments described below, there are cases where corresponding structures are labeled with the same reference numerals and descriptions are omitted.

[0055] Furthermore, in the following description, expressions such as "parallel," "orthogonal," "center," and "coaxial," which indicate relative or absolute configurations, not only rigorously describe such configurations but also indicate a state of relative displacement by angle or distance with tolerances and to the extent that the same function can be obtained.

[0056] (First Embodiment)

[0057] Figure 1 This is a cross-sectional view showing the schematic structure of the reducer 1 according to the first embodiment. For example, the reducer 1 is provided at a joint of a robot. Figure 1 In this configuration, the speed reducer 1 is located between the motor support 200 (an example of the object component in the claim) and the robot arm 500.

[0058] The motor bracket 200 is located between the servo motor 300 and the reducer 1. The motor bracket 200 is fixed to the reducer 1 by multiple bolts 400.

[0059] The motor bracket 200 is formed such that it surrounds the output shaft 301 of the servo motor 300 from the radial outside. Figure 1 The central axis La is shown as a ring. The central axis La of the motor bracket 200 is configured to overlap with the central axis Lb of the servo motor 300 when viewed from the direction along the central axis La.

[0060] The motor bracket 200 includes a mounting portion 201 for mounting the reducer 1. The mounting portion 201 is provided such that it protrudes from the main body 202 of the motor bracket 200 toward the reducer 1 in the direction along the central axis La. The mounting portion 201 is formed such that its thickness, viewed in the direction along the central axis La, is smaller than the thickness of the main body 202. Figure 1 As shown, the mounting part 201 has the mounting part 23 (described later) of the reducer 1 inserted inside it. The end face 203 of the mounting part 201, located on the reducer 1 side along the central axis La, abuts against the flange 22 (described later) of the reducer 1. The end of the motor bracket 200, located on the opposite side of the reducer 1 along the central axis La, is fixed to the servo motor 300.

[0061] The servo motor 300 is fixed to the motor bracket 200 by bolts, for example (not shown). The servo motor 300 is a power source that generates power for rotating the arm 500. The servo motor 300 has an output shaft 301 protruding in the direction along the central axis Lb. The output shaft 301 rotates about the central axis Lb. Figure 1 As shown, an input gear 302 is provided on the outer peripheral surface of the top end of the output shaft 301, which is connected to the transmission gear 11 of the reducer 1, which will be discussed later.

[0062] Alternatively, an input shaft connected to the transmission gear 11 can be provided independently of the output shaft 301 of the servo motor 300 for the motor bracket 200.

[0063] In this case, an input gear is provided on the outer peripheral surface of the top end 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 is made into a hollow shaft, and the output shaft 301 of the servo motor 300 is inserted into the input shaft, thereby enabling the connection between the input shaft and the output shaft 301 of the servo motor 300.

[0064] The arm 500 is fixed to the reducer 1 by, for example, bolts 600. The power input from the reducer 1 to the arm 500 relative to the servo motor 300 reduces the output rotational speed. Furthermore, the arm 500 is driven to rotate around the central axis Lc of the reducer 1. The arm 500 is fixed to the gear carrier 5 of the reducer 1, which will be discussed later.

[0065] [Gear reducer]

[0066] Figure 2 This is a schematic enlarged cross-sectional view of the reducer 1 according to this embodiment. The reducer 1 includes a gear carrier 5, which will be discussed later, and rotates about a central axis Lc. The reducer 1 is a rotational mechanism that changes the rotational speed of the power input from the servo motor 300 and outputs it via the gear carrier 5.

[0067] Furthermore, in the following description, the servo motor 300 side along the central axis Lc is defined as the input side, and the arm 500 side along the central axis Lc is defined as the output side.

[0068] like Figure 2 As shown, the reducer 1 includes a housing 2 and a reduction mechanism 3.

[0069] The housing 2 has a main body 21 and a flange 22. The main body 21 is formed into a cylindrical shape centered on the central axis Lc. That is, the central axis Lc of the reducer 1 functions as the axis of the main body 21. The main body 21 has openings at both ends along the central axis Lc (i.e., the end on the input side and the end on the output side). The main body 21 internally houses the reduction mechanism 3.

[0070] The reduction gear unit 3 includes a gear carrier unit 5 and an input-side angular contact ball bearing 6. In other words, the main body 21 internally houses the gear carrier unit 5 and the input-side angular contact ball bearing 6.

[0071] The input-side end of the housing 2 serves as a mounting portion 23 for mounting to the motor bracket 200. The mounting portion 23 extends from the input-side end face 22a of the flange 22 in a direction along the central axis Lc (axis) relative to the outer ring 6a of the input-side angular contact ball bearing 6, which will be discussed later. In other words, the mounting portion 23 protrudes distally from the end face 22a of the flange 22 along the central axis Lc (axis) relative to the outer ring 6a of the input-side angular contact ball bearing 6. The top surface 23a of the mounting portion 23 is located closer to the motor bracket 200 than the outer ring 6a of the input-side angular contact ball bearing 6. The mounting portion 23, viewed along the central axis Lc, is formed in an annular shape centered on the central axis Lc. The mounting portion 23 is inserted into the interior of the mounting portion 201 of the motor bracket 200 (see reference). Figure 1 The outer peripheral surface of the mounting part 23 contacts, for example, the inner peripheral surface of the mounted part 201.

[0072] Figure 3 It includes Figure 2 An enlarged view of the connection between the flange portion 22 and the mounting portion 23.

[0073] like Figure 3 As shown, an O-ring 700 is provided on the outer peripheral surface of the mounting part 23 (see reference). Figure 1 The groove 23b is formed continuously in the circumferential direction centered on the central axis Lc when viewed from the direction along the central axis Lc. The groove 23b is formed by recessing from the outer peripheral surface of the mounting portion 23 toward the radially inward side centered on the central axis Lc.

[0074] A recess 23c is provided at the root of the mounting portion 23 on the side closer to the flange portion 22. The recess 23c is formed by recessing the outer peripheral surface of the mounting portion 23 toward the inside in the radial direction centered on the central axis Lc. That is, the recess 23c is formed by locally recessing the housing 2. This recess 23c functions as a so-called relief groove portion.

[0075] As Figure 3 shown, the flange portion 22 is connected to the mounting portion 23, thereby forming a corner portion between the flange portion 22 and the mounting portion 23. In the present embodiment, this corner portion is referred to as an input-side corner portion C1. More specifically, the input-side corner portion C1 is formed between the end face 22a of the flange portion 22 and the outer peripheral surface (the bottom face 23d of the recess 23c) of the mounting portion 23 by connecting them.

[0076] In addition, the input-side corner portion C1 can be either a so-called right angle (Japanese: pin angle) or a so-called rounded corner. That is, the input-side corner portion C1 can also be formed by connecting the end face 22a of the flange portion 22 and the outer peripheral surface of the mounting portion 23 in a zigzag manner. Further, the input-side corner portion C1 can also be formed by connecting the end face 22a of the flange portion 22 and the outer peripheral surface of the mounting portion 23 in a curved manner. The above-described recess 23c is connected to the input-side corner portion C1.

[0077] In addition, the end face 22b of the flange portion 22 on the output side is connected to the outer peripheral surface of the main body portion 21, thereby forming a corner portion between the end face 22b and the main body portion 21. In the present embodiment, this corner portion is referred to as an output-side corner portion C2.

[0078] In addition, the output-side corner portion C2 can also be either a so-called right angle or a so-called rounded corner, similarly to the input-side corner portion C1. Further, a recess 21a connected to the output-side corner portion C2 is provided on the outer peripheral surface of the main body portion 21.

[0079] The flange portion 22 is formed to project from the main body portion 21 in a direction intersecting with the direction along the central axis Lc of the main body portion 21. That is, the flange portion 22 is arranged so as to project from the outer peripheral surface of the main body portion 21 toward the outside in the radial direction centered on the central axis Lc. When viewed from the direction along the central axis Lc, the flange portion 22 is continuously provided in the circumferential direction centered on the central axis Lc.

[0080] The end face 22a of the flange portion 22 functions as a contact surface that contacts the mounting portion 201 of the motor bracket 200. The end face 22b of the flange portion 22 functions as a contact surface that contacts the head of the bolt 400. A plurality of bolt holes 22c penetrating from the end face 22a to the end face 22b are provided in the flange portion 22. The bolts 400 are respectively inserted into these bolt holes 22c.

[0081] Figure 4 yes Figure 2 Sectional view IV-IV. (See example) Figure 4 As shown, multiple bolt holes 22c are discretely formed along the circumferential direction centered on the central axis Lc.

[0082] like Figure 2 and Figure 4 As shown, a plurality of pin grooves 21b are formed on the inner circumferential surface of the main body 21. These pin grooves 21b are respectively arranged to extend along the central axis Lc and are formed into a semi-circular shape when viewed from the direction along the central axis Lc. These pin grooves 21b are arranged at equal intervals in the circumferential direction centered on the central axis Lc.

[0083] like Figure 2 As shown, the reduction mechanism 3 includes an internal toothed pin 4, a gear carrier 5, an input-side angular contact ball bearing 6, an output-side angular contact ball bearing 7, multiple (e.g., 3) crankshafts 8, a first oscillating gear 9, a second oscillating gear 10, and multiple transmission gears 11.

[0084] like Figure 2 and Figure 4 As shown, the internal toothed pins 4 are arranged according to each pin groove 21b. Specifically, each internal toothed pin 4 is embedded in a corresponding pin groove 21b, arranged in a posture extending in the direction along the central axis Lc. Thus, a plurality of internal toothed pins 4 are arranged at equal intervals in the circumferential direction centered on 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 toothed pins 4.

[0085] like Figure 2 As shown, the gear carrier 5 is housed inside the housing 2 in a configuration coaxial with the housing 2. The gear carrier 5 rotates relative to the housing 2 in the circumferential direction about the central axis Lc. Specifically, the gear carrier 5 is located radially inside the housing 2 and is supported by an input-side angular contact ball bearing 6 and an output-side angular contact ball bearing 7.

[0086] The gear carrier portion 5 includes a base portion 5a and an end plate portion 5b. The base portion 5a and the end plate portion 5b are fixed together by bolts 5c. That is, the base portion 5a and the end plate portion 5b can be separated by removing the bolts 5c.

[0087] like Figure 2 As shown, the base 5a contacts the back side of the inner ring 7b of the output-side angular contact ball bearing 7 from the output side. The end plate 5b contacts the back side 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 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.

[0088] The input-side angular contact ball bearing 6 and the output-side angular contact ball bearing 7 are located between the housing 2 and the gear carrier 5, supporting the gear carrier 5 so that it can rotate freely relative to the housing 2. The input-side angular contact ball bearing 6 is positioned closer to the input side than the output-side angular contact ball bearing 7. The central axes of the input-side angular contact ball bearing 6 and the output-side angular contact ball bearing 7 overlap with the central axis Lc of the reducer 1. That is, the central axis Lc also functions as the central axis of the input-side angular contact ball bearing 6 and the output-side angular contact ball bearing 7.

[0089] The input-side angular contact ball bearing 6 has an outer ring 6a, an inner ring 6b, and multiple rolling elements 6c.

[0090] The outer peripheral surface of the outer ring 6a contacts the inner peripheral surface of the main body 21 of the housing 2. More specifically, the outer peripheral surface of the outer ring 6a of the input-side angular contact ball bearing 6 contacts the inner peripheral surface of the mounting portion 23. The outer peripheral surface of the outer ring 6a is pressed forcefully against the inner peripheral surface of the main body 21. This prevents the outer peripheral surface of the outer ring 6a from sliding relative to the inner peripheral surface of the main body 21.

[0091] The inner circumferential surface of the inner ring 6b contacts the gear carrier portion 5. The inner circumferential surface of the inner ring 6b is pressed forcefully against the gear carrier portion 5. This prevents the inner circumferential surface of the inner ring 6b from sliding relative to the outer circumferential surface of the gear carrier portion 5. Alternatively, the inner ring 6b can be integrated with the gear carrier portion 5.

[0092] Multiple rolling elements 6c, each a sphere, are disposed between the outer ring 6a and the inner ring 6b. The inner ring 6b is able to rotate relative to the outer ring 6a in a circumferential direction centered on the central axis Lc using these rolling elements 6c.

[0093] The input-side angular contact ball bearing 6 is configured such that the back side of the outer ring 6a faces the output side and the front side of the outer ring 6a faces the input side. In other words, the input-side angular contact ball bearing 6 is configured such that the back side of the inner ring 6b faces the input side and the front side of the inner ring 6b faces the output side. For example... Figure 2 As shown, the back surface of the outer ring 6a contacts the housing 2. Additionally, the back surface of the inner ring 6b contacts the gear carrier portion 5. In other words, the input-side angular contact ball bearing 6 is sandwiched between the housing 2 and the gear carrier portion 5 along the central axis Lc.

[0094] The output-side angular contact ball bearing 7 has an outer ring 7a, an inner ring 7b, and multiple rolling elements 7c.

[0095] The outer peripheral surface of the outer ring 7a contacts the inner peripheral surface of the main body 21 of the housing 2. The outer peripheral surface of the outer ring 7a is pressed forcefully against the inner peripheral surface of the main body 21. This prevents the outer peripheral surface of the outer ring 7a from sliding relative to the inner peripheral surface of the main body 21.

[0096] The inner circumferential surface of the inner ring 7b contacts the gear carrier portion 5. The inner circumferential surface of the inner ring 7b is pressed forcefully against the gear carrier portion 5. This prevents the inner circumferential surface of the inner ring 7b from sliding relative to the outer circumferential surface of the gear carrier portion 5. Alternatively, the inner ring 7b can be integrated with the gear carrier portion 5.

[0097] Multiple rolling elements 7c, each a ball, are disposed between the outer ring 7a and the inner ring 7b. The inner ring 7b is able to rotate relative to the outer ring 7a in a circumferential direction centered on the central axis Lc using these rolling elements 7c.

[0098] The output-side angular contact ball bearing 7 is configured such that the back side of the outer ring 7a faces the input side and the front side of the outer ring 7a faces the output side. In other words, the output-side angular contact ball bearing 7 is configured such that the back side of the inner ring 7b faces the output side and the front side of the inner ring 7b faces the input side. For example... Figure 2 As shown, the back surface of the outer ring 7a contacts the housing 2. Additionally, the back surface of the inner ring 7b contacts the gear carrier portion 5. In other words, the output-side angular contact ball bearing 7 is sandwiched between the housing 2 and the gear carrier portion 5 along the central axis Lc.

[0099] like Figure 2 As shown, multiple crankshafts 8 are arranged at equal intervals in the circumferential direction centered on the central axis Lc within the housing 2 (see reference). Figure 4 Each crankshaft 8 is supported by a pair of crankshaft bearings, crankshaft bearing 12 and crankshaft bearing 13, and is rotatable about an axis relative to the gear 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 with the shaft body 8c.

[0100] Each crankshaft 8 has a mating portion 8d at its input side end along the central axis Lc for mounting the transmission gear 11. Furthermore, the reducer 1 in this embodiment is not limited to... Figure 2 For example, the mating part can be positioned at the output end of the crankshaft 8, and the transmission gear 11 can be mounted on the mating part on the output side.

[0101] Each first oscillating gear 9 is disposed inside the housing 2 and mounted on the first eccentric portion 8a of the crankshaft 8 by means of the first roller bearing 14. If the crankshaft 8 rotates and the first eccentric portion 8a rotates eccentrically, each first oscillating gear 9 rotates in conjunction with the eccentric rotation and oscillates while engaging with the internal tooth pin 4.

[0102] The second oscillating gear 10 is disposed inside the housing 2 and is mounted on the second eccentric portion 8b of the crankshaft 8 by means of the second roller bearing 15. If the crankshaft 8 rotates and the second eccentric portion 8b rotates eccentrically, each of the second oscillating gears 10 is linked to the eccentric rotation and oscillates and rotates while meshing with the internal tooth pin 4.

[0103] 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 about an axis that is the same as the axis of rotation of the crankshaft 8. Each transmission gear 11 has external teeth 11a that mesh with the input gear 302.

[0104] Next, refer to Figure 3 The positional relationship between the input side corner C1 and the input side angular contact ball bearing 6 is explained.

[0105] Figure 3 The line of action L1 shown is an imaginary 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, the back side of the outer ring 6a of the input-side angular contact ball bearing 6 is located on the output side, and the front side of the outer ring 6a is located on the input side. Therefore, as... Figure 3 As shown, the line of action L1 is inclined relative to the central axis Lc in a manner that it approaches the central axis Lc in the direction along the central axis Lc as it moves toward the top of the mounting part 23.

[0106] When a preload is applied to the input-side angular contact ball bearing 6, such as Figure 3 As shown, the preload can be represented by a vector that overlaps with the line of action L1 and originates from the center of the rolling element 6c. In this embodiment, this vector is defined as the preload vector V. That is, the preload vector V originates from the center of the rolling element 6c, overlaps with the line of action L1, and extends radially outward from the center axis Lc. The portion of the housing 2 that strongly bears the preload acting on the input-side angular contact ball bearing 6 is 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 angular portion C1 is positioned at a position P, which is closer to the top end of the mounting portion 23 than the position where the line of action L1 of the input-side angular contact ball bearing 6 intersects with the outer peripheral surface of the main body portion 21.

[0107] Therefore, the input-side end face 22a of the flange portion 22 is positioned near the top end of the mounting portion 23 in the direction along the central axis Lc, at a position P where it intersects the line of action L1 of the input-side angular contact ball bearing 6 and the outer peripheral surface of the main body portion 21. Furthermore, the output-side end face 22b of the flange portion 22 is positioned near the arm 500 in the direction along the central axis Lc, at a position P where it intersects the line of action L1 of the input-side angular contact ball bearing 6 and the outer peripheral surface of the main body portion 21. Thus, the line of action L1 of the input-side angular contact ball bearing passes through the interior of the flange portion 22.

[0108] The flange 22 protrudes from the cylindrical main body 21 in a direction intersecting the central axis Lc. Therefore, compared to the portion of the housing 2 without the flange 22, the portion of the housing 2 with the flange 22 has a larger thickness and higher rigidity in the direction intersecting the central axis Lc of the main body 21. In other words, the line of action L1 of the input-side angular contact ball bearing 6 passes through this more rigid portion of the housing 2. Therefore, the more rigid portion of the housing 2 can withstand the preload acting on the input-side angular contact ball bearing 6, and deformation of the mounting portion 23 caused by the preload can be suppressed.

[0109] [Function and Effect of Speed ​​Reducers]

[0110] The reducer 1 of this embodiment includes a housing 2, a gear carrier 5, and an input-side angular contact ball bearing 6. The input-side angular contact ball bearing 6 is located between the housing 2 and the gear carrier 5, supporting the gear carrier 5 so that it can rotate freely relative to the housing 2.

[0111] The housing 2 has a main body portion 21 and a flange portion 22. The main body portion 21 internally houses the gear carrier portion 5 and the input-side angular contact ball bearing 6, and the input-side angular contact ball bearing 6 contacts the inner circumferential surface of the main body portion 21. The main body portion 21 is formed in a cylindrical shape. The flange portion 22 protrudes from the main body portion 21 in a direction intersecting the direction along the central axis Lc. The main body portion 21 has a mounting portion 23, which is provided to extend from the flange portion 22 in a direction along the axis relative to the outer ring 6a of the input-side angular contact ball bearing 6, and can be mounted on the motor bracket 200.

[0112] The input-side corner portion C1 between the flange portion 22 and the mounting portion 23 is positioned such that it is located at a position P, which is closer to the top end of the mounting portion 23 than the position P where the line of action L1 of the input-side angular contact ball bearing 6 intersects with the outer peripheral surface of the main body portion 21.

[0113] As described above, the speed reducer 1 of this embodiment can suppress the deformation of the housing 2 caused by the preload applied to the input-side angular contact ball bearing 6. Therefore, according to the speed reducer 1, even if the mounting portion 23 provided to the housing 2 protrudes relative to the surrounding parts, deformation of the mounting portion 23 can be suppressed.

[0114] Furthermore, in the reducer 1 of this embodiment, the housing 2 has a recess 23c, which is connected to the input-side corner portion C1, and the recess 23c is formed by partially recessing the housing 2. By providing such a recess 23c, the formation of the housing 2 can be facilitated. By providing the recess 23c, the thickness of the portion of the housing 2 with the recess 23c is smaller than that without the recess 23c. Furthermore, in the reducer 1 of this embodiment, the line of action L1 of the input-side angular contact ball bearing 6 does not pass through the recess 23c. Therefore, it is possible to suppress the strong action of the preload applied to the input-side angular contact ball bearing 6 on the portion of the housing 2 with the recess 23c. Therefore, according to the reducer 1 of this embodiment, the recess 23c can be provided in the housing 2, and deformation of the mounting portion 23 can be suppressed. Alternatively, the recess 23c may not be provided.

[0115] Furthermore, in the reducer 1 of this embodiment, the housing 2 has a groove 23b formed circumferentially along the central axis of the input-side angular contact ball bearing 6 on the outer peripheral surface of the mounting portion 23. By providing such a groove 23b, an O-ring 700 can be installed. By providing the groove 23b, the thickness of the portion of the housing 2 with the groove 23b is smaller than when the groove 23b is not provided. Moreover, in the reducer 1 of this embodiment, the line of action L1 of the input-side angular contact ball bearing 6 does not pass through the groove 23b. Therefore, it is possible to suppress the strong action of the preload applied to the input-side angular contact ball bearing 6 on the portion of the housing 2 with the groove 23b. Thus, according to the reducer 1 of this embodiment, the groove 23b can be provided in the housing 2, and deformation of the mounting portion 23 can be suppressed. Alternatively, the groove 23b may not be provided.

[0116] Furthermore, in the reducer 1 of this embodiment, the line of action L1 of the input-side angular contact ball bearing 6 is inclined relative to the central axis Lc in a manner that it approaches the central axis Lc towards the top of the mounting portion 23 in the direction along the central axis Lc. Therefore, the position P where the line of action L1 intersects the circumferential surface of the main body 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, by arranging the input-side corner portion C1 at a position closer to the top of the mounting portion 23 than position P, the length dimension of the required flange portion 22 in the direction along the central axis Lc can be suppressed.

[0117] [Example]

[0118] For example, in the speed reducer 1 of the above embodiment, it can be designed in a way that satisfies the following conditions.

[0119] • The inner diameter of the main body 21 is 60mm or more and smaller than 200mm.

[0120] • The wall thickness of the mounting section 23 is 3mm or more and 10mm or less.

[0121] • The outer diameter of the input-side angular contact ball bearing 6 in the state of being removed from the interior of the main body 21 is 5 μm or more but less than 50 μm larger than the inner diameter of the main body 21.

[0122] • The preload acting on the input-side angular contact ball bearing 6, which is housed inside the main body 21, is 1000N or more and 50000N or less.

[0123] The inner diameter of the main body 21 is the diameter D1 of the internal space of the main body 21 at the location where the input-side angular contact ball bearing 6 is installed (refer to...). Figure 2 The wall thickness dimension of the mounting part 23 is the radial thickness dimension D2 of the mounting part 23 centered on the central axis Lc (refer to...). Figure 3 Furthermore, the thickness dimension D2 is the value at the location where the recess 23c and groove 23b are not provided. The outer diameter dimension of the input-side angular contact ball bearing 6 refers to the diameter D3 of the circle drawn by the outer circumferential surface of the outer ring 6a of the input-side angular contact ball bearing 6 (refer to...). Figure 2 In addition, in Figure 2 In this case, the input-side angular contact ball bearing 6 is housed inside the main body 21. Therefore, the diameter D1 of the internal space of the main body 21 is the same as the diameter D3 of the circle drawn by the outer circumferential surface of the outer ring 6a of the input-side angular contact ball bearing 6.

[0124] Furthermore, the reducer 1 in the above embodiment can also be designed in a way that satisfies the following conditions.

[0125] • The inner diameter of the main body 21 is 200mm or more and smaller than 290mm.

[0126] • The wall thickness of the mounting section 23 is 7mm or more and 18mm or less.

[0127] • The outer diameter of the input-side angular contact ball bearing 6 in the state of being removed from the interior of the main body 21 is 5 μm or more but less than 70 μm larger than the inner diameter of the main body 21.

[0128] • The preload acting on the input-side angular contact ball bearing 6, which is housed inside the main body 21, is 15,000 N or more and 80,000 N or less.

[0129] Furthermore, the reducer 1 in the above embodiment can also be designed in a way that satisfies the following conditions.

[0130] • The inner diameter of the main body 21 is 290mm or more but less than 390mm.

[0131] • The wall thickness of the mounting section 23 is 14mm or more and 28mm or less.

[0132] • The outer diameter of the input-side angular contact ball bearing 6 in the state of being removed from the interior of the main body 21 is 15 μm or more but less than 70 μm larger than the inner diameter of the main body 21.

[0133] • The preload acting on the input-side angular contact ball bearing 6, which is housed inside the main body 21, is 30,000 N or more and 130,000 N or less.

[0134] By designing the reducer 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 Standard. Therefore, the reducer 1 can be reliably mounted on the motor bracket 200.

[0135] (Second Implementation)

[0136] Next, refer to Figure 5 The second embodiment will now be described. Figure 5 This is a partially enlarged view showing the schematic structure of the reducer 1A according to the second embodiment. Furthermore, the same reference numerals are used for the same aspects as in the first embodiment. Additionally, in the description of the second embodiment, there are instances where the same names as those in the first embodiment are used, and some descriptions are omitted.

[0137] like Figure 5 As shown, 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 a line L2 orthogonal to the central axis Lc. The component Vb, originating from the center of the rolling element 6c and extending radially toward the input-side angular contact ball bearing 6, is the main cause of deformation of the mounting portion 23.

[0138] like Figure 5 As shown, in this embodiment, the input side corner portion C1 is positioned at the point P1 where the line L2 intersects with the outer peripheral surface of the main body portion 21, near the top end of the mounting portion 23. In this reducer 1A of this embodiment, the component Vb, which is the main cause of deformation of the mounting portion 23, faces the flange portion 22. That is, in the reducer 1A of this embodiment, the component Vb, which is the main cause of deformation of the mounting portion 23, can be borne by the portion of the preload vector V containing the housing 2 with higher rigidity. Therefore, the deformation of the housing 2 caused by the preload vector V can be further suppressed.

[0139] Furthermore, similar to the reducer 1 in the first embodiment described above, the reducer 1A of this embodiment can suppress deformation of the mounting portion 23 even when the recess 23c and the groove 23b are provided.

[0140] Furthermore, the reducer 1A of this embodiment can be designed in a manner that satisfies the following conditions.

[0141] • The inner diameter of the main body 21 is 60mm or more and smaller than 200mm.

[0142] • The wall thickness of the mounting section 23 is 3mm or more and 10mm or less.

[0143] • The outer diameter of the input-side angular contact ball bearing 6 in the state of being removed from the interior of the main body 21 is 5 μm or more but less than 50 μm larger than the inner diameter of the main body 21.

[0144] • The preload acting on the input-side angular contact ball bearing 6, which is housed inside the main body 21, is 1000N or more and 50000N or less.

[0145] By designing the reducer 1A under the above conditions, the deformation of the mounting part 23 can be kept within the h7 tolerance range of the Japanese Industrial Standard.

[0146] In addition, the reducer 1A of this embodiment can also be designed in a way that satisfies the following conditions.

[0147] • The inner diameter of the main body 21 is 200mm or more and smaller than 290mm.

[0148] • The wall thickness of the mounting section 23 is 7mm or more and 18mm or less.

[0149] • The outer diameter of the input-side angular contact ball bearing 6 in the state of being removed from the interior of the main body 21 is 5 μm or more but less than 70 μm larger than the inner diameter of the main body 21.

[0150] • The preload acting on the input-side angular contact ball bearing 6, which is housed inside the main body 21, is 15,000 N or more and 80,000 N or less.

[0151] By designing the reducer 1A under the above conditions, the deformation of the mounting part 23 can be kept within the h7 tolerance range of the Japanese Industrial Standard.

[0152] In addition, the reducer 1A of this embodiment can also be designed in a way that satisfies the following conditions.

[0153] • The inner diameter of the main body 21 is 290mm or more but less than 390mm.

[0154] • The wall thickness of the mounting section 23 is 14mm or more and 28mm or less.

[0155] • The outer diameter of the input-side angular contact ball bearing 6 in the state of being removed from the interior of the main body 21 is 15 μm or more but less than 70 μm larger than the inner diameter of the main body 21.

[0156] • The preload acting on the input-side angular contact ball bearing 6, which is housed inside the main body 21, is 30,000 N or more and 130,000 N or less.

[0157] By designing the reducer 1A under the above conditions, the deformation of the mounting part 23 can be kept within the h7 tolerance range of the Japanese Industrial Standard.

[0158] (Third Implementation)

[0159] Next, refer to Figure 6 The third embodiment will now be described.

[0160] Figure 6 This is a schematic diagram of the coordination robot 100. In the description of this embodiment, the vertical and horizontal directions of the coordination robot 100 are defined as the vertical and horizontal directions when the coordination robot 100 is placed on the setting surface F.

[0161] like Figure 6 As shown, the coordinated robot 100 (an example of the robot in the claims) comprises: a base portion 101 (an example of the first or second component in the claims) mounted on a mounting surface F; a rotating head 102 (an example of the first or second component in the claims) disposed on the base portion 101; an arm unit 103 (an example of the first or second component in the claims) rotatably assembled to the upper part of the rotating head 102; speed reducers (first speed reducer 10A, second speed reducer 10B, and third speed reducer 10C) assembled to the joint portions (first joint portion 106a, second joint portion 106b, and third joint portion 106c) of the base portion 101, the rotating head 102, and the arm unit 103; servo motors (first servo motor 107, second servo motor 108, and third servo motor 109) serving as drive sources; and an end effector 110 mounted to the arm unit 103.

[0162] The rotating head 102 is connected to the base portion 101 in a manner that allows it to rotate freely about a first rotation axis LA. This connected portion functions as a first joint portion 106a. A first reducer 10A and a first servo motor 107 are assembled at the first joint portion 106a. The first rotation axis LA is, for example, aligned with the vertical direction.

[0163] The rotation of the first servo motor 107 is transmitted to the rotary head 102 via the first reducer 10A. As a result, the rotary head 102 is driven to rotate about the first rotation axis LA relative to the base portion 101.

[0164] The arm unit 103 consists of two arms (first arm 104 and second arm 105) that are longer in one direction, for example. One end of the first arm 104 is connected to the upper part of the rotating head 102 in a manner that allows it to rotate freely about a second rotation axis LB. This connection point functions as a second joint 106b. A second reducer 10B and a second servo motor 108 are assembled at the second joint 106b. The second rotation axis LB is, for example, aligned with the horizontal direction.

[0165] The rotation of the second servo motor 108 is transmitted to the first arm 104 via the second reducer 10B. Thus, the first arm 104 is driven to rotate relative to the rotating head 102 about the second rotation axis LB. For example, the first arm 104 is driven to swing relative to the base portion 101 in the front-to-back direction.

[0166] One end of the second arm 105 is connected to the other end of the first arm 104 in a manner that allows it to rotate freely about the third rotation axis LC. This connection point functions as the third joint 106c. The third reducer 10C and the third servo motor 109 are assembled at the third joint 106c. The third rotation axis LC is, for example, aligned with the horizontal direction.

[0167] The rotation of the third servo motor 109 is transmitted to the second arm 105 via the third reducer 10C. Thus, the second arm 105 is driven to rotate relative to the first arm 104 about the third rotation axis LC. For example, the second arm 105 is driven to swing in the vertical direction relative to the first arm 104.

[0168] The end effector 110 is mounted at 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.

[0169] The first reducer 10A, the second reducer 10B, and the third reducer 10C of the coordination robot 100 in this embodiment are respectively composed of the reducer 1 of the first embodiment or the reducer 1A of the second embodiment.

[0170] Therefore, the coordination robot 100 of this embodiment becomes a robot that suppresses deformation of the mounting portions 23 of the first reducer 10A, the second reducer 10B, and the third reducer 10C. Furthermore, any one or two of the first reducer 10A, the second reducer 10B, and the third reducer 10C can also be constituted by the reducer 1 of the first embodiment or the reducer 1A of the second embodiment. The reducers (first reducer 10A, second reducer 10B, and third reducer 10C) can be mounted as servo motors (first servo motor 107, second servo motor 108, and third servo motor 109) for example. Alternatively, the reducers (first reducer 10A, second reducer 10B, and third reducer 10C) can also be mounted on a motor bracket or other component not shown.

[0171] This invention is not limited to the embodiments described above, but includes various modifications to the embodiments described above without departing from the spirit of this invention.

[0172] For example, in the above embodiments, the following situation was described: Taking the coordination robot 100 as an example, this coordination robot 100 is provided with three reducers (first reducer 10A, second reducer 10B, and third reducer 10C). However, it is not limited to this. A structure can be as follows: for example, the robot has two components (first component and second component), a reducer is provided between the two components, and the second component rotates relative to the first component. The structure of the above embodiments can be adopted in various robots having such a structure.

[0173] Furthermore, in the above embodiments, a speed reducer was described as an example of a rotating mechanism. However, the rotating mechanism is not limited to these. The structure of the above embodiments can be adopted in various rotating mechanisms having the following components: a housing; a rotating body; and a bearing located between the housing and the rotating body, supporting the rotating body so that it can rotate freely relative to the housing. That is, the bearing is not limited to angular contact ball bearings. For example, other bearings such as tapered roller bearings can be used as bearings.

[0174] Furthermore, in the above embodiment, the mounting portion 23 provided to the housing 2 is formed protruding from the flange portion 22 to a position farther than the input-side angular contact ball bearing 6. However, the mounting portion 23 may not extend to the distance from the input-side angular contact ball bearing 6.

[0175] In the embodiments disclosed in this specification, a component composed of multiple objects can either be integrated into one object, or the component composed of a single object can be divided into multiple objects. Regardless of whether they are integrated or not, they can be configured in a manner that achieves the purpose of the invention.

Claims

1. A rotating mechanism comprising: case; Solids of revolution; and A bearing, located between the housing and the rotating body, supports the rotating body so that it can rotate freely relative to the housing. The housing has: A cylindrical main body houses the rotating body and the bearing, with the bearing contacting the inner circumferential surface of the main body; and A flange portion, which is arranged from the main body portion in a direction intersecting the direction along the axis of the main body portion. The main body has a mounting portion that extends from the flange portion in a direction along the axis and is capable of being mounted to an object component. The corner between the flange and the mounting portion is positioned closer to the top end of the mounting portion than the point where the line of action of the bearing intersects the outer peripheral surface of the main body. The bearing is an angular contact ball bearing. The corner portion is positioned near the top end of the mounting portion at a location where the line intersects the outer peripheral surface of the main body portion. The line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element.

2. The rotating mechanism according to claim 1, wherein, The mounting portion is provided such that it extends relative to the outer ring of the bearing in a direction along the axis from the flange portion.

3. The rotating mechanism according to claim 1 or 2, wherein, The housing has a recess that connects to the corner portion, and the recess is formed by partially recessing the housing.

4. The rotating mechanism according to claim 1 or 2, wherein, The housing has a groove formed circumferentially on the outer peripheral surface of the mounting portion along the central axis of the bearing.

5. The rotating mechanism according to claim 1 or 2, wherein, The line of action is inclined relative to the axis in a manner that it moves closer to the axis as it approaches the top of the mounting portion in the direction along the axis of the main body.

6. The rotating mechanism according to claim 1, wherein, The inner diameter of the main body is 60mm or more but less than 200mm. The wall thickness of the mounting part is 3mm or more and 10mm or less. When the angular contact ball bearing is removed from the interior of the main body, its outer diameter is 5 μm larger than the inner diameter of the main body but less than 50 μm. The preload acting on the angular contact ball bearing housed inside the main body is 1000N or more and 50000N or less.

7. The rotating mechanism according to claim 1, wherein, The inner diameter of the main body is 200mm or more but less than 290mm. The wall thickness of the mounting part is 7mm or more and 18mm or less. When the angular contact ball bearing is removed from the interior of the main body, its outer diameter is 5 μm larger than the inner diameter of the main body but less than 70 μm. 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.

8. The rotating mechanism according to claim 1, wherein, The inner diameter of the main body is 290 mm or more but less than 390 mm. The wall thickness of the mounting part is 14mm or more and 28mm or less. When the angular contact ball bearing is removed from the interior of the main body, its outer diameter is 15 μm larger than the inner diameter of the main body but less than 70 μm. 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.

9. A rotating mechanism comprising: case; Solids of revolution; and An angular contact ball bearing, located between the housing and the rotating body, supports the rotating body so that it can rotate freely relative to the housing. The housing has: A cylindrical main body internally houses the rotating body and the angular contact ball bearing, wherein the angular contact ball bearing contacts the inner circumferential surface of the main body; 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 has a mounting portion that extends from the flange portion relative to the outer ring of the angular contact ball bearing in a direction along the axis, and is capable of being mounted on an object component. The line of action of the angular contact ball bearing is inclined relative to the axis in a manner that it approaches the axis as it moves toward the top 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 near the top of the mounting portion at a location where a line intersects the outer peripheral surface of the main body. This line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element. The housing also has: A recess, which connects to the corner portion, and the recess is formed by partially recessing the housing; and A groove is formed circumferentially on the outer peripheral surface of the mounting portion, centered on the central axis of the angular contact ball bearing. The inner diameter of the main body is 60mm or more but less than 200mm. The wall thickness of the mounting part is 3mm or more and 10mm or less. When the angular contact ball bearing is removed from the interior of the main body, its outer diameter is 5 μm larger than the inner diameter of the main body but less than 50 μm. The preload acting on the angular contact ball bearing housed inside the main body is 1000N or more and 50000N or less.

10. A rotating mechanism comprising: case; Solids of revolution; and An angular contact ball bearing, located between the housing and the rotating body, supports the rotating body so that it can rotate freely relative to the housing. The housing has: A cylindrical main body internally houses the rotating body and the angular contact ball bearing, wherein the angular contact ball bearing contacts the inner circumferential surface of the main body; 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 has a mounting portion that extends from the flange portion relative to the outer ring of the angular contact ball bearing in a direction along the axis, and is capable of being mounted on an object component. The line of action of the angular contact ball bearing is inclined relative to the axis in a manner that it approaches the axis as it moves toward the top 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 near the top of the mounting portion at a location where a line intersects the outer peripheral surface of the main body. This line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element. The housing also has: A recess, which connects to the corner portion, and the recess is formed by partially recessing the housing; and A groove is formed circumferentially on the outer peripheral surface of the mounting portion, centered on the central axis of the angular contact ball bearing. The inner diameter of the main body is 200mm or more but less than 290mm. The wall thickness of the mounting part is 7mm or more and 18mm or less. When the angular contact ball bearing is removed from the interior of the main body, its outer diameter is 5 μm larger than the inner diameter of the main body but less than 70 μm. 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.

11. A rotating mechanism comprising: case; Solids of revolution; and An angular contact ball bearing, located between the housing and the rotating body, supports the rotating body so that it can rotate freely relative to the housing. The housing has: A cylindrical main body internally houses the rotating body and the angular contact ball bearing, wherein the angular contact ball bearing contacts the inner circumferential surface of the main body; 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 has a mounting portion that extends from the flange portion relative to the outer ring of the angular contact ball bearing in a direction along the axis, and is capable of being mounted on an object component. The line of action of the angular contact ball bearing is inclined relative to the axis in a manner that it approaches the axis as it moves toward the top 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 near the top of the mounting portion at a location where a line intersects the outer peripheral surface of the main body. This line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element. The housing also has: A recess, which connects to the corner portion, and the recess is formed by partially recessing the housing; and A groove is formed circumferentially on the outer peripheral surface of the mounting portion, centered on the central axis of the angular contact ball bearing. The inner diameter of the main body is 290 mm or more but less than 390 mm. The wall thickness of the mounting part is 14mm or more and 28mm or less. When the angular contact ball bearing is removed from the interior of the main body, its outer diameter is 15 μm larger than the inner diameter of the main body but less than 70 μm. 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.

12. A robot that possesses: Component 1; The second component; and A rotating mechanism, disposed between the first component and the second component, connects the second component to allow it to rotate relative to the first component. The rotating mechanism includes: case; Solids of revolution; and A bearing, located between the housing and the rotating body, supports the rotating body so that it can rotate freely relative to the housing. The housing has: A cylindrical main body houses the rotating body and the bearing, with the bearing contacting the inner circumferential surface of the main body; and A flange portion, which is arranged from the main body portion in a direction intersecting the direction along the axis of the main body portion. The main body has a mounting portion that extends from the flange portion in a direction along the axis and is capable of being mounted to an object component. The corner between the flange and the mounting portion is positioned closer to the top end of the mounting portion than the point where the line of action of the bearing intersects the outer peripheral surface of the main body. The bearing is an angular contact ball bearing. The corner portion is positioned near the top end of the mounting portion at a location where the line intersects the outer peripheral surface of the main body portion. The line is orthogonal to the central axis of the angular contact ball bearing and passes through the center of the rolling element.

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