CN116533224A

CN116533224A - Rotating mechanism and robot

Info

Publication number: CN116533224A
Application number: CN202310049513.0A
Authority: CN
Inventors: 镰形州一
Original assignee: Nabtesco Corp
Current assignee: Nabtesco Corp
Priority date: 2022-02-03
Filing date: 2023-02-01
Publication date: 2023-08-04

Abstract

The invention provides a rotating mechanism and a robot. In the rotation mechanism of the present invention, a housing (2) has: a tubular main body (21) which houses the carrier (5) and the input side angular contact ball bearing (6) therein, and the input side angular contact ball bearing is in contact with the inner peripheral surface of the main body; and a flange portion (22) protruding from the main body portion in a direction intersecting with a direction along the axis of the main body portion. The main body part has a mounting part (23), and the mounting part (23) is provided so as to extend from the flange part (22) in a direction along the axis line in contact with the outer ring (6 a) of the ball bearing at an angle on the input side, and is capable of being mounted on a target member. An input side corner (C1) between the flange (22) and the mounting portion (23) is disposed closer to the tip end side of the mounting portion (23) than a position where the line of action (L1) of the input side corner contact ball bearing intersects the outer peripheral surface of the main body.

Description

Rotating mechanism and robot

Technical Field

The invention relates to a rotating mechanism and a robot.

Background

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 a carrier rotatably relative to an outer cylinder. Patent document 2 discloses a driving device. The drive device disclosed in patent document 2 includes a main bearing disposed between a carrier and a housing.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2017-227333

Patent document 2: japanese patent laid-open No. 2020-133761

Disclosure of Invention

Problems to be solved by the invention

The eccentric oscillating gear device disclosed in patent document 1 and the driving device disclosed in patent document 2 are provided with an angular ball bearing as a main bearing for rotatably supporting a rotating body. For example, a rotation mechanism for rotatably supporting a rotating body by such a main bearing includes a housing for housing the main bearing. Such a part of the housing is used as a mounting portion to be mounted on a target member such as a motor or a robot. However, the mounting portion may be deformed by a preload applied to the main bearing. When the mounting portion is deformed to deviate from the dimension specification tolerance, there is a problem that the rotation mechanism cannot be mounted on the target member.

The present invention has been made in view of the above-described problems, and provides a rotation mechanism capable of suppressing deformation of a mounting portion that can be mounted on a target member, and a robot including the rotation mechanism.

Solution for solving the problem

(1) The rotary mechanism according to claim 1 of the present invention includes: a housing; a rotating body; and a bearing that is located between the housing and the rotating body and supports the rotating body rotatably with respect to the housing. The housing has: a cylindrical main body portion that accommodates the rotating body and the bearing therein, and the bearing is in contact with an inner peripheral surface of the main body portion; and a flange portion disposed from the main body portion in a direction intersecting a direction along an axis of the main body portion. The main body portion has an attachment portion that is provided in a direction along the axis from the flange portion and is attachable to a target member. The corner between the flange portion and the mounting portion is disposed so as to be located closer to the distal end side of the mounting portion than a position where the line of action of the bearing intersects the outer peripheral surface of the main body portion.

The portion of the housing that is strongly subjected to the preload applied to the bearing is a portion located on the action line of the bearing. In the rotary mechanism according to claim 1 of the present invention, the corner portion between the flange portion and the mounting portion is disposed at a position shifted from a position where the line of action of the bearing intersects the outer peripheral surface of the main body portion toward the tip end side of the mounting portion. Therefore, the line of action of the bearing passes through the inside of the flange portion. The flange portion is disposed so as to protrude from the cylindrical body portion in a direction intersecting with a direction along the axis of the body portion. Therefore, the portion of the housing where the flange portion is provided becomes a portion having a larger thickness dimension and a higher rigidity in the direction intersecting the axial direction of the main body portion than the portion of the housing where the flange portion is not provided. That is, in the rotary mechanism according to claim 1 of the present invention, the line of action of the bearing passes through a portion of the housing where the rigidity is high.

Therefore, the preload acting on the bearing can be received by the portion of the housing having high rigidity, and deformation of the housing due to the preload can be suppressed. Therefore, according to the rotation mechanism of claim 1 of the present invention, even if the attachment portion provided to the housing is formed so as to protrude from the surrounding portion, deformation of the attachment portion can be suppressed.

(2) In the above configuration, the mounting portion may be provided so as to extend from the flange portion in a direction along the axis line with respect to the outer ring of the bearing.

(3) In the above configuration, the bearing may be an angular ball bearing. The corner portion may be disposed closer to the distal end side of the mounting portion than a line intersecting the outer peripheral surface of the main body portion, the line being orthogonal to the central axis of the angular ball bearing and passing through the center of the rolling element.

(4) In the above configuration, the case may have a recess portion connected to the corner portion, and the recess portion may be formed by partially recessing the case.

(5) In the above configuration, the housing may have a groove portion formed on an outer peripheral surface of the mounting portion along a circumferential direction around a central axis of the bearing.

(6) In the above configuration, the line of action may be inclined with respect to the axis so as to approach the axis toward the distal end of the attachment portion in a direction along the axis of the main body portion.

(7) In the above configuration, the inner diameter of the main body may be 60mm or more and less than 200mm, the wall thickness of the mounting portion may be 3mm or more and 10mm or less, and the outer diameter of the angular ball bearing in a state of being taken out from the inside of the main body may be 5 μm or more and 50 μm or less than the inner diameter of the main body, and a preload applied to the angular ball bearing accommodated in the inside of the main body may be 1000N or more and 50000N or less.

(8) In the above configuration, the inner diameter of the main body may be 200mm or more and less than 290mm, the wall thickness of the mounting portion may be 7mm or more and 18mm or less, and the outer diameter of the angular ball bearing in a state of being taken out from the inside of the main body may be 5 μm or more and 70 μm or less than the inner diameter of the main body, and a preload applied to the angular ball bearing accommodated in the inside of the main body may be 15000N or more and 80000N or less.

(9) In the above configuration, the inner diameter of the main body may be 290mm or more and less than 390mm, the wall thickness of the attachment portion may be 14mm or more and 28mm or less, and the outer diameter of the angular ball bearing in a state of being taken out from the inside of the main body may be 15 μm or more and 70 μm or less than the inner diameter of the main body, and the preload applied to the angular ball bearing accommodated in the inside of the main body may be 30000N or more and 130000N or less.

(10) The rotation mechanism according to claim 2 of the present invention includes: a housing; a rotating body; and an angular ball bearing that is located between the housing and the rotating body and supports the rotating body rotatably with respect to the housing. The housing has: a cylindrical main body portion that houses the rotating body and the angular ball bearing therein, and the angular ball bearing is in contact with an inner peripheral surface of the main body portion; and a flange portion protruding from the main body portion in a direction intersecting with a direction along an axis of the main body portion. The main body portion has an attachment portion that is provided so as to extend from the flange portion in a direction along the axis with respect to an outer ring of the angular ball bearing, and is attachable to a target member. The action line of the angular ball bearing is inclined with respect to the axis in such a manner as to approach the axis in a direction along the axis of the main body portion toward the tip end of the mounting portion. The corner between the flange portion and the mounting portion is disposed so as to be located closer to the distal end side of the mounting portion than a position where a line, which is orthogonal to the center 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. The housing further has: a recess portion connected to the corner portion, the recess portion being formed by partially recessing the housing; and a groove portion formed on an outer peripheral surface of the mounting portion along a circumferential direction centering on a central axis of the angular ball bearing. The inner diameter of the main body is 60mm or more and less than 200 mm. The wall thickness of the mounting part is 3mm to 10 mm. The outer diameter dimension of the angular ball bearing in a state of being taken out from the inside of the main body is in a range of 5 μm to 50 μm larger than the inner diameter dimension of the main body. The preload applied to the angular ball bearing housed in the main body is 1000N to 50000N.

The preload applied to the angular ball bearing can be considered as a vector directed radially outward of the angular ball bearing along the line of action from the center of the rolling elements of the angular ball bearing. This vector is defined as the preload vector. The preload vector can be considered to be decomposed into a component along the central axis of the angular contact ball bearing and a component along a line orthogonal to the central axis of the angular contact ball bearing. The component along the line orthogonal to the center axis of the angular ball bearing is directed in the radial direction of the angular ball bearing with the center of the rolling element as the starting point, and is a factor of deforming the mounting portion provided so as to protrude from the outer ring of the angular ball bearing.

In the rotary mechanism according to claim 2 of the present invention, the corner portion between the flange portion and the attachment portion is disposed so as to be located closer to the distal end side of the attachment portion than a position where a line, which is orthogonal to the center 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.

Therefore, out of the components included in the preload vector, a component that is a factor of deforming the mounting portion is directed toward the flange portion. The flange portion is formed protruding from the cylindrical body portion in a direction intersecting with a direction along the axis of the body portion. Therefore, the portion of the housing where the flange portion is provided becomes a portion having a larger thickness dimension and a higher rigidity in the direction intersecting the axial direction of the main body portion than the portion of the housing where the flange portion is not provided. That is, in the rotary mechanism according to claim 2 of the present invention, the component included in the preload vector can be received by the portion of the housing having high rigidity, which is a factor of deforming the mounting portion.

Thus, deformation of the housing due to the preload vector can be suppressed. Therefore, according to the rotary mechanism of claim 2 of the present invention, even if the mounting portion provided to the housing is formed so as to protrude from the surrounding portion, deformation of the mounting portion can be suppressed.

In the rotary mechanism according to claim 2 of the present invention, the housing further includes: a recess connected to the corner and formed by partially recessing the case; and a groove portion formed on the outer peripheral surface of the mounting portion along a circumferential direction centered on the central axis of the angular ball bearing. By providing these concave portions and groove portions, the main body portion is partially thinned as compared with the case where these concave portions and groove portions are not provided. However, in the rotary mechanism according to claim 2 of the present invention, the component included in the preload vector can be received by the portion of the housing having high rigidity, which is a factor of deforming the mounting portion, and therefore, even if the recess or the groove portion is provided, the deformation of the mounting portion can be suppressed.

In the rotary mechanism according to claim 2 of the present invention, the inner diameter of the main body is 60mm or more and smaller than 200 mm. The wall thickness of the mounting part is 3mm to 10 mm. The outer diameter of the angular ball bearing in a state of being taken out from the inside of the main body is in a range of 5 μm to 50 μm larger than the inner diameter of the main body. The preload applied to the angular ball bearing housed in the main body is 1000N to 50000N.

Thus, the deformation amount of the mounting portion can be made within the h7 tolerance range of japanese industrial standards.

(11) The rotation mechanism according to claim 3 of the present invention includes: a housing; a rotating body; and an angular ball bearing that is located between the housing and the rotating body and supports the rotating body rotatably with respect to the housing. The housing has: a cylindrical main body portion that houses the rotating body and the angular ball bearing therein, and the angular ball bearing is in contact with an inner peripheral surface of the main body portion; and a flange portion protruding from the main body portion in a direction intersecting with a direction along an axis of the main body portion. The main body portion has an attachment portion that is provided so as to extend from the flange portion in a direction along the axis with respect to an outer ring of the angular ball bearing, and is attachable to a target member. The action line of the angular ball bearing is inclined with respect to the axis in such a manner as to approach the axis in a direction along the axis of the main body portion toward the tip end of the mounting portion. The corner between the flange portion and the mounting portion is disposed so as to be located closer to the distal end side of the mounting portion than a position where a line, which is orthogonal to the center 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. The housing further has: a recess portion connected to the corner portion, the recess portion being formed by partially recessing the housing; and a groove portion formed on an outer peripheral surface of the mounting portion along a circumferential direction centering on a central axis of the angular ball bearing. The inner diameter of the main body is 200mm or more and less than 290 mm. The wall thickness of the mounting part is 7mm to 18 mm. The outer diameter dimension of the angular ball bearing in a state of being taken out from the inside of the main body is in a range of 5 μm to 70 μm larger than the inner diameter dimension of the main body. The preload applied to the angular ball bearing housed in the main body is 15000N or more and 80000N or less.

In the rotary mechanism according to claim 3 of the present invention, the corner portion between the flange portion and the attachment portion is disposed so as to be located closer to the distal end side of the attachment portion than a position where a line, which is orthogonal to the center 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. Therefore, out of the components included in the preload vector, a component that is a factor of deforming the mounting portion is directed toward the flange portion. The flange portion is formed protruding from the cylindrical body portion in a direction intersecting with a direction along the axis of the body portion. Therefore, the portion of the housing where the flange portion is provided becomes a portion having a larger thickness dimension and a higher rigidity in the direction intersecting the axial direction of the main body portion than the portion of the housing where the flange portion is not provided. That is, in the rotary mechanism according to claim 3 of the present invention, the component included in the preload vector can be received by the portion of the housing having high rigidity, which is a factor of deforming the mounting portion.

Thus, deformation of the housing due to the preload vector can be suppressed. Therefore, according to the rotation mechanism of claim 3 of the present invention, even if the attachment portion provided to the housing is formed so as to protrude from the surrounding portion, deformation of the attachment portion can be suppressed.

In addition, in the rotary mechanism according to claim 3 of the present invention, the housing further includes: a recess connected to the corner and formed by partially recessing the case; and a groove portion formed on the outer peripheral surface of the mounting portion along a circumferential direction centered on the central axis of the angular ball bearing. By providing these concave portions and groove portions, the main body portion is partially thinned as compared with the case where these concave portions and groove portions are not provided. However, in the rotary mechanism according to claim 3 of the present invention, the component included in the preload vector can be received by the portion of the housing having high rigidity, which is a factor of deforming the mounting portion, and therefore, even if the recess or the groove portion is provided, the deformation of the mounting portion can be suppressed.

In the rotary mechanism according to claim 3 of the present invention, the inner diameter of the main body is 200mm or more and less than 290 mm. The wall thickness of the mounting part is 7mm to 18 mm. The outer diameter of the angular ball bearing in a state of being taken out from the inside of the main body is in a range of 5 μm to 70 μm larger than the inner diameter of the main body. The preload applied to the angular ball bearing housed in the main body is 15000N or more and 80000N or less.

(12) The rotation mechanism according to claim 4 of the present invention includes: a housing; a rotating body; and an angular ball bearing that is located between the housing and the rotating body and supports the rotating body rotatably with respect to the housing. The housing has: a cylindrical main body portion that houses the rotating body and the angular ball bearing therein, and the angular ball bearing is in contact with an inner peripheral surface of the main body portion; and a flange portion protruding from the main body portion in a direction intersecting with a direction along an axis of the main body portion. The main body portion has an attachment portion that is provided so as to extend from the flange portion in a direction along the axis with respect to an outer ring of the angular ball bearing, and is attachable to a target member. The action line of the angular ball bearing is inclined with respect to the axis in such a manner as to approach the axis in a direction along the axis of the main body portion toward the tip end of the mounting portion. The corner between the flange portion and the mounting portion is disposed so as to be located closer to the distal end side of the mounting portion than a position where a line, which is orthogonal to the center 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. The housing further has: a recess portion connected to the corner portion, the recess portion being formed by partially recessing the housing; and a groove portion formed on an outer peripheral surface of the mounting portion along a circumferential direction centering on a central axis of the angular ball bearing. The inner diameter of the main body is 290mm or more and less than 390 mm. The wall thickness of the mounting part is 14mm to 28 mm. The outer diameter dimension of the angular ball bearing in a state of being taken out from the inside of the main body is in a range of 15 μm to 70 μm larger than the inner diameter dimension of the main body. The preload applied to the angular ball bearing housed in the main body is 30000N to 130000N.

In the rotary mechanism according to the 4 th aspect of the present invention, the corner portion between the flange portion and the attachment portion is disposed so as to be located closer to the distal end side of the attachment portion than a position where a line, which is orthogonal to the center 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. Therefore, out of the components included in the preload vector, a component that is a factor of deforming the mounting portion is directed toward the flange portion. The flange portion is formed protruding from the cylindrical body portion in a direction intersecting with a direction along the axis of the body portion. Therefore, the portion of the housing where the flange portion is provided becomes a portion having a larger thickness dimension and a higher rigidity in the direction intersecting the axial direction of the main body portion than the portion of the housing where the flange portion is not provided. That is, in the rotary mechanism according to the 4 th aspect of the present invention, the component included in the preload vector can be received by the portion of the housing having high rigidity, which is a factor of deforming the mounting portion.

Thus, deformation of the housing due to the preload vector can be suppressed. Therefore, according to the rotation mechanism of the 4 th aspect of the present invention, even if the attachment portion provided to the housing is formed so as to protrude from the surrounding portion, deformation of the attachment portion can be suppressed.

In the rotary mechanism according to the 4 th aspect of the present invention, the housing further includes: a recess connected to the corner and formed by partially recessing the case; and a groove portion formed on the outer peripheral surface of the mounting portion along a circumferential direction centered on the central axis of the angular ball bearing. By providing these concave portions and groove portions, the main body portion is partially thinned as compared with the case where these concave portions and groove portions are not provided. However, in the rotary mechanism according to the 4 th aspect of the present invention, the component included in the preload vector can be received by the portion of the housing having high rigidity, which is a factor of deforming the mounting portion, and therefore, even if the recess portion or the groove portion is provided, the deformation of the mounting portion can be suppressed.

In the rotary mechanism according to the 4 th aspect of the present invention, the inner diameter of the main body is 290mm or more and less than 390 mm. The wall thickness of the mounting part is 14mm to 28 mm. The outer diameter of the angular ball bearing in a state of being taken out from the inside of the main body is in a range of 15 μm to 70 μm larger than the inner diameter of the main body. The preload applied to the angular ball bearing housed in the main body is 30000N or more and 130000N or less.

(13) A robot according to claim 5 of the present invention includes: 1 st component; a 2 nd member; and a rotation mechanism provided between the 1 st member and the 2 nd member, and connecting the 2 nd member to rotate relative to the 1 st member. The rotation mechanism is provided with: a housing; a rotating body; and a bearing that is located between the housing and the rotating body and supports the rotating body rotatably with respect to the housing. The housing has: a cylindrical main body portion that accommodates the rotating body and the bearing therein, and the bearing is in contact with an inner peripheral surface of the main body portion; and a flange portion disposed from the main body portion in a direction intersecting a direction along an axis of the main body portion. The main body portion has an attachment portion that is provided in a direction along the axis from the flange portion and is attachable to a target member. The corner between the flange and the mounting portion is disposed closer to the distal end side of the mounting portion than a position where the line of action of the bearing intersects the outer peripheral surface of the main body portion.

In the rotation mechanism, a corner portion between the flange portion and the attachment portion is disposed at a position closer to a distal end side of the attachment portion than a position where a line of action of the bearing intersects with an outer peripheral surface of the main body portion. Therefore, the line of action of the bearing passes through the inside of the flange portion. The flange portion is disposed so as to protrude from the cylindrical body portion in a direction intersecting with a direction along the axis of the body portion. Therefore, the portion of the housing where the flange portion is provided becomes a portion having a larger thickness dimension and a higher rigidity in the direction intersecting the axial direction of the main body portion than the portion of the housing where the flange portion is not provided. That is, in the rotation mechanism, the line of action of the bearing passes through a portion of the housing where the rigidity is high. Therefore, the preload acting on the bearing can be received by the portion of the housing having high rigidity, and deformation of the housing due to the preload can be suppressed. Therefore, according to the rotation mechanism, even if the mounting portion provided to the housing is formed so as to protrude from the surrounding portion, deformation of the mounting portion can be suppressed. The robot according to claim 5 of the present invention includes the above-described rotation mechanism. Thus, the deformation of the mounting portion of the rotation mechanism can be suppressed, and the rotation mechanism and the 1 st member or the 2 nd member can be reliably connected.

ADVANTAGEOUS EFFECTS OF INVENTION

The above-described rotation mechanism and robot can suppress deformation of the attachment portion provided so as to be attachable to the target member.

Drawings

Fig. 1 is a diagram including a cross-sectional view showing a schematic configuration of a speed reducer according to embodiment 1 of the present invention.

Fig. 2 is a schematic cross-sectional view of a speed reducer according to embodiment 1 of the present invention.

Fig. 3 is an enlarged view of a main portion of fig. 2.

Fig. 4 is a cross-sectional view of IV-IV of fig. 2.

Fig. 5 is an enlarged view of a main part showing a schematic configuration of a speed reducer according to embodiment 2 of the present invention.

Fig. 6 is a schematic configuration diagram of a coordination robot according to embodiment 3 of the present invention.

Description of the reference numerals

1. 1A, 10B, 10C, and a speed reducer (rotating mechanism); 2. a housing; 5. a carrier portion (rotating body); 6. input side angular contact ball bearings (angular contact ball bearings, bearings); 6a, an outer ring; 6c, rolling elements; 21. a main body portion; 21a, a recess; 21b, pin slots; 22. a flange portion; 23. a mounting part; 23b, groove portions; 23c, a recess; 100. coordinated robots (robots); 101. a base portion (1 st member, 2 nd member); 102. a rotary head (1 st member, 2 nd member); 103. an arm unit (1 st member, 2 nd member); 104. arm 1 (1 st member, 2 nd member); 105. arm 2 (1 st member, 2 nd member); 107. a 1 st servo motor (target member); 108. a 2 nd servo motor (target member); 109. a 3 rd servo motor (target member); 200. a motor bracket (target member); c1, input side corner (corner); l1, action line; l2, line; lc, central axis (axis).

Detailed Description

Hereinafter, a rotating mechanism and a robot according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the embodiments described below, the same reference numerals are given to corresponding structures, and description thereof may be omitted.

In the following description, the expressions "parallel", "orthogonal", "center", "coaxial", and the like indicate relative or absolute arrangements, and represent not only such arrangements but also states in which angles and distances having tolerances and degrees to which the same functions can be obtained are relatively shifted.

(embodiment 1)

Fig. 1 is a diagram including a cross-sectional view showing a schematic configuration of a speed reducer 1 according to embodiment 1. For example, the speed reducer 1 is provided in a joint portion of the robot. In fig. 1, a speed reducer 1 is located between a motor bracket 200 (an example of an object member in claims) and an arm 500 of a robot.

The motor bracket 200 is located between the servo motor 300 and the speed reducer 1. The motor bracket 200 is fixed to the speed reducer 1 by a plurality of bolts 400.

The motor holder 200 is formed in a ring shape centering on the central axis La shown in fig. 1 so as to surround the output shaft 301 of the servomotor 300 from the radially outer side. The center axis La of the motor holder 200 is disposed so as to overlap with the center axis Lb of the servomotor 300 as viewed in the direction along the center axis La.

The motor bracket 200 includes a mounted portion 201 to which the speed reducer 1 is mounted. The mounted portion 201 is provided so as to protrude from the main body portion 202 of the motor bracket 200 toward the speed reducer 1 side in a direction along the central axis La. The mounted portion 201 is formed such that the thickness dimension is smaller than the thickness dimension of the main body portion 202 as seen in the direction along the central axis La. As shown in fig. 1, the mounted portion 201 is inserted therein with a mounting portion 23 of the speed reducer 1, which will be discussed later. An end surface 203 of the mounted portion 201 on the side of the speed reducer 1 along the central axis La abuts against a flange portion 22 of the speed reducer 1, which will be discussed later. An end portion of the motor bracket 200 located on the opposite side of the speed reducer 1 along the center axis La is fixed to the servo motor 300.

The servomotor 300 is fixed to the motor bracket 200 by, for example, a bolt not shown. The servomotor 300 is a power source for generating power for rotationally driving the arm 500. The servomotor 300 includes an output shaft 301 protruding in a direction along the central axis Lb. The output shaft 301 rotates about the central axis Lb. As shown in fig. 1, an input gear 302 connected to a transmission gear 11 of the speed reducer 1, which will be described later, is provided on the outer peripheral surface of the distal end portion of the output shaft 301.

Further, an input shaft connected to the transmission gear 11 may be provided independently of the output shaft 301 of the servomotor 300 for the motor bracket 200.

In this case, an input gear is provided on the outer peripheral surface of the distal end portion of the input shaft, and the input shaft is connected to the output shaft 301 of the servomotor 300. For example, the input shaft is a hollow shaft, and the output shaft 301 of the servomotor 300 is inserted into the input shaft, whereby the input shaft and the output shaft 301 of the servomotor 300 can be connected.

Arm 500 is fixed to speed reducer 1 by, for example, bolt 600. An output of which the rotation speed is reduced with respect to the power of the servomotor 300 is input from the speed reducer 1 to the arm 500. The arm 500 is driven to rotate about the center axis Lc of the speed reducer 1. The arm 500 is fixed to a carrier portion 5 of the speed reducer 1, which will be discussed later.

[ speed reducer ]

Fig. 2 is a schematic enlarged cross-sectional view of the speed reducer 1 of the present embodiment. The speed reducer 1 includes a carrier portion 5 to be discussed later, which rotates around a central axis Lc. The speed reducer 1 is a rotation mechanism that changes the rotation speed of power input from the servomotor 300 and outputs the power through the carrier portion 5.

In the following description, the servo motor 300 side along the center axis Lc is defined as an input side, and the arm 500 side along the center axis Lc is defined as an output side.

As shown in fig. 2, the speed reducer 1 includes a housing 2 and a speed reduction mechanism 3.

The housing 2 has a main body portion 21 and a flange portion 22. The main body 21 is formed in a cylindrical shape centered on the central axis Lc. That is, the center axis Lc of the speed reducer 1 functions as the axis of the main body 21. The ends of the main body portion 21 on both sides along the central axis Lc (i.e., the end on the input side and the end on the output side) are open. The main body 21 houses the reduction mechanism 3 therein.

The reduction mechanism 3 includes a carrier 5 and an input side angular contact ball bearing 6. That is, the main body 21 houses the carrier 5 and the input side angular contact ball bearing 6 therein.

The end of the housing 2 on the input side serves as a mounting portion 23 that is mountable to the motor bracket 200. The mounting portion 23 is provided so as to extend from an end surface 22a of the flange portion 22 on the input side in a direction along the central axis Lc (axis line) with respect to an outer ring 6a of the input side angular contact ball bearing 6 to be discussed later. That is, the mounting portion 23 is provided so as to protrude to a distant place from the end surface 22a of the flange portion 22 along the central axis Lc (axis line) with respect to the outer ring 6a of the input side angular contact ball bearing 6. The distal end 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 is formed in an annular shape centering on the central axis Lc as viewed in a direction along the central axis Lc. The mounting portion 23 is inserted into the mounted portion 201 of the motor bracket 200 (see fig. 1). The outer peripheral surface of the mounting portion 23 is in contact with the inner peripheral surface of the mounted portion 201, for example.

Fig. 3 is an enlarged view including a connection portion between the flange portion 22 and the mounting portion 23 in fig. 2.

As shown in fig. 3, a groove 23b in which an O-ring 700 (see fig. 1) is disposed is provided on the outer peripheral surface of the mounting portion 23. The groove 23b is continuously formed along a circumferential direction centered on the central axis Lc as viewed in a direction along the central axis Lc. The groove 23b is formed recessed from the outer peripheral surface of the mounting portion 23 toward the inside in the radial direction around the central axis Lc.

A recess 23c is provided at a root portion of the mounting portion 23 on the flange portion 22 side. The recess 23c is formed by recessing the outer peripheral surface of the mounting portion 23 toward the inside in the radial direction around the central axis Lc. That is, the recess 23c is formed by partially recessing the housing 2. The concave portion 23c functions as a so-called relief portion.

As shown in fig. 3, the flange portion 22 is connected to the mounting portion 23, so that an angle portion is formed between the flange portion 22 and the mounting portion 23. In the present embodiment, this corner is referred to as an input side corner C1. More specifically, the input-side corner C1 is formed between the end surface 22a of the flange 22 and the outer peripheral surface of the mounting portion 23 by connecting the end surface 22a to the outer peripheral surface of the mounting portion 23 (the bottom surface 23d of the recess 23C).

The input side corner C1 may be a so-called right angle or a so-called rounded corner. That is, the input side corner C1 may be formed by connecting the end surface 22a of the flange 22 and the outer peripheral surface of the mounting portion 23 in a meandering manner. The input side corner C1 may be formed by connecting the end surface 22a of the flange 22 and the outer peripheral surface of the mounting portion 23 in a curved manner. The concave portion 23C is connected to the input side corner C1.

The end surface 22b of the flange 22 on the output side is connected to the outer peripheral surface of the main body 21, so that an angle is formed between the end surface 22b and the main body 21. In the present embodiment, this corner is referred to as an output side corner C2.

The output side corner C2 may be a so-called right angle or a so-called rounded corner, as in the input side corner C1. Further, a concave portion 21a connected to the output side corner C2 is provided on the outer peripheral surface of the main body 21.

The flange portion 22 is formed so as to protrude from the main body portion 21 in a direction intersecting with a direction along the central axis Lc of the main body portion 21. That is, the flange portion 22 is disposed so as to protrude outward in the radial direction around the central axis Lc from the outer peripheral surface of the main body portion 21. The flange portion 22 is continuously provided in the circumferential direction around the central axis Lc as viewed in the direction along the central axis Lc.

The end surface 22a of the flange 22 functions as a contact surface with the mounted portion 201 of the motor bracket 200. The end surface 22b of the flange 22 functions as a contact surface with the head of the bolt 400. The flange 22 is provided with a plurality of bolt holes 22c penetrating from the end face 22a to the end face 22 b. Bolts 400 are inserted into the bolt holes 22c, respectively.

Fig. 4 is a cross-sectional view of IV-IV of fig. 2. As shown in fig. 4, a plurality of bolt holes 22c are formed discretely along the circumferential direction around the central axis Lc.

As shown in fig. 2 and 4, a plurality of pin grooves 21b are formed in the inner peripheral surface of the main body 21. The pin grooves 21b are each provided so as to extend along the central axis Lc, and are each formed in a semicircular shape as viewed in the direction along the central axis Lc. The pin grooves 21b are arranged at equal intervals in the circumferential direction around the central axis Lc.

As shown in fig. 2, the reduction mechanism 3 includes an inner pin 4, a carrier 5, an input side angular contact ball bearing 6, an output side angular contact ball bearing 7, a plurality (e.g., 3) of crankshafts 8, a 1 st wobble gear 9, a 2 nd wobble gear 10, and a plurality of transmission gears 11.

As shown in fig. 2 and 4, the inner toothed pin 4 is provided for each pin groove 21b. Specifically, each of the internal tooth pins 4 is fitted into the corresponding pin groove 21b, and is disposed in a posture extending in a direction along the central axis Lc. Thus, the plurality of inner teeth pins 4 are arranged at equal intervals along the circumferential direction centered on the central axis Lc. The external teeth 9a of the 1 st swing gear 9 and the external teeth 10a of the 2 nd swing gear 10 mesh with these internal teeth pins 4.

As shown in fig. 2, the carrier portion 5 is housed inside the housing 2 in a state of being arranged coaxially with the housing 2. The carrier portion 5 rotates relative to the housing 2 in the circumferential direction around the central axis Lc. Specifically, the carrier portion 5 is disposed radially inward of the housing 2 and supported by the input side angular contact ball bearing 6 and the output side angular contact ball bearing 7.

The 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 by bolts 5 c. That is, by detaching the bolts 5c, the base portion 5a and the end plate portion 5b can be separated.

As shown in fig. 2, the base 5a contacts the back surface of the inner ring 7b of the output side angular contact ball bearing 7 from the output side. The end plate portion 5b contacts the back surface of the inner ring 6b of the ball bearing 6 from the input side to the input side corner. Therefore, by adjusting the screwing amount of the bolt 5c in the direction of 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.

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 carrier 5, and support the carrier 5 rotatably with respect to the housing 2. The input side angular contact ball bearing 6 is disposed on the input side of the output side angular contact ball bearing 7. The central axes of the input side angle contact ball bearing 6 and the output side angle contact ball bearing 7 overlap with the central axis Lc of the speed reducer 1. That is, the center axis Lc also functions as the center axes of the input side angular contact ball bearing 6 and the output side angular contact ball bearing 7.

The input side angular contact ball bearing 6 includes an outer ring 6a, an inner ring 6b, and a plurality of rolling elements 6c.

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 is in contact with the inner peripheral surface of the mounting portion 23. The outer peripheral surface of the outer ring 6a is strongly pressed against the inner peripheral surface of the main body 21. Thereby, the outer peripheral surface of the outer ring 6a is prevented from sliding with respect to the inner peripheral surface of the main body portion 21.

The inner peripheral surface of the inner ring 6b contacts the carrier portion 5. The inner peripheral surface of the inner ring 6b is strongly pressed against the carrier portion 5. Thereby, the inner peripheral surface of the inner ring 6b is prevented from sliding with respect to the outer peripheral surface of the carrier portion 5. The inner ring 6b may be integrated with the carrier portion 5.

The plurality of rolling elements 6c are spherical bodies, respectively, and are disposed between the outer ring 6a and the inner ring 6 b. The inner ring 6b is rotatable with respect to the outer ring 6a in the circumferential direction around the central axis Lc by the rolling elements 6c.

The input side angular contact ball bearing 6 is disposed such that the back surface of the outer ring 6a faces the output side and the front surface of the outer ring 6a faces the input side. That is, the input side angular contact ball bearing 6 is disposed such that the back surface of the inner ring 6b faces the input side and the front surface of the inner ring 6b faces the output side. As shown in fig. 2, the back surface of the outer ring 6a is in contact with the housing 2. The back surface of the inner ring 6b is in contact with the carrier portion 5. That is, the input side angular contact ball bearing 6 is sandwiched by the housing 2 and the carrier portion 5 in the direction along the central axis Lc.

The output side angular contact ball bearing 7 includes an outer ring 7a, an inner ring 7b, and a plurality of rolling elements 7c.

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 strongly pressed against the inner peripheral surface of the main body 21. Thereby, the outer peripheral surface of the outer ring 7a is prevented from sliding with respect to the inner peripheral surface of the main body 21.

The inner peripheral surface of the inner ring 7b contacts the carrier portion 5. The inner peripheral surface of the inner ring 7b is strongly pressed against the carrier portion 5. Thereby, the inner peripheral surface of the inner ring 7b is prevented from sliding with respect to the outer peripheral surface of the carrier portion 5. The inner ring 7b may be integrated with the carrier portion 5.

The plurality of rolling elements 7c are spherical bodies, respectively, and are disposed between the outer ring 7a and the inner ring 7 b. The inner ring 7b is rotatable relative to the outer ring 7a in the circumferential direction around the central axis Lc by the rolling elements 7c.

The output side angular contact ball bearing 7 is disposed such that the back surface of the outer ring 7a faces the input side and the front surface of the outer ring 7a faces the output side. That is, the output side angular contact ball bearing 7 is disposed such that the back surface of the inner ring 7b faces the output side and the front surface of the inner ring 7b faces the input side. As shown in fig. 2, the back surface of the outer ring 7a is in contact with the housing 2. The back surface of the inner ring 7b is in contact with the carrier portion 5. That is, the output side angular contact ball bearing 7 is sandwiched by the housing 2 and the carrier portion 5 in the direction along the central axis Lc.

As shown in fig. 2, the plurality of crankshafts 8 are disposed at equal intervals in the circumferential direction around the central axis Lc in the case 2 (see fig. 4). Each crankshaft 8 is supported by a pair of crankshaft bearings 12 and 13 so as to be rotatable about an axis relative to the carrier portion 5. Each crankshaft 8 has a shaft main body 8c, and a 1 st eccentric portion 8a and a 2 nd eccentric portion 8b formed integrally with the shaft main body 8 c.

A fitted portion 8d to which the transmission gear 11 is attached is provided at an end portion of each crankshaft 8 on the input side along the central axis Lc. The speed reducer 1 of the present embodiment is not limited to the example of fig. 2, and the fitted portion may be disposed at the output side end of the crankshaft 8, and the transmission gear 11 may be attached to the output side fitted portion.

Each 1 st oscillating gear 9 is disposed inside the housing 2 and is mounted on the 1 st eccentric portion 8a of the crankshaft 8 via a 1 st roller bearing 14. When the crank shaft 8 rotates and the 1 st eccentric portion 8a rotates eccentrically, each 1 st oscillating gear 9 oscillates while meshing with the internal gear pin 4 in association with the eccentric rotation.

The 2 nd oscillating gear 10 is disposed inside the housing 2 and is mounted on the 2 nd eccentric portion 8b of the crankshaft 8 via a 2 nd roller bearing 15. When the crankshaft 8 rotates and the 2 nd eccentric portion 8b rotates eccentrically, each 2 nd oscillating gear 10 oscillates while meshing with the internal gear pin 4 in association with the eccentric rotation.

Each transmission gear 11 transmits rotation of the input gear 302 of the servomotor 300 to the crankshaft 8. Each transmission gear 11 is fixed to the fitted portion 8d of the crankshaft 8. Each transmission gear 11 rotates integrally with the crankshaft 8 about the same axis as the rotation axis of the crankshaft 8. Each transmission gear 11 has external teeth 11a meshed with the input gear 302.

Next, a positional relationship between the input side corner C1 and the input side corner contact ball bearing 6 will be described with reference to fig. 3.

The action line L1 shown in fig. 3 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 the present embodiment, the rear 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. Therefore, as shown in fig. 3, the action line L1 is inclined with respect to the central axis Lc so as to approach the central axis Lc toward the tip end of the mounting portion 23 in the direction along the central axis Lc.

When a preload is applied to the input side angular contact ball bearing 6, the preload can be represented by a vector that overlaps the line of action L1 and starts from the center of the rolling element 6c, as shown in fig. 3. In the present embodiment, this vector is defined as a preload vector V. That is, the preload vector V is superimposed on the acting line L1 with the center of the rolling element 6c as the start point, and is directed radially outward with the center axis Lc as the center. The portion of the housing 2 that strongly receives the preload acting on the input side angular contact ball bearing 6 is a portion located on the line of action L1 of the input side angular contact ball bearing 6. In the speed reducer 1 of the present embodiment, the input side corner C1 is disposed closer to the distal end side of the mounting portion 23 than the position P at which the line of action L1 of the input side corner contact ball bearing 6 intersects the outer peripheral surface of the main body portion 21.

Therefore, the input-side end surface 22a of the flange portion 22 is disposed so as to be located closer to the distal end side of the mounting portion 23 than a position P where the action line L1 of the input-side angular contact ball bearing 6 intersects the outer peripheral surface of the main body portion 21 in the direction along the central axis Lc. The end surface 22b of the flange portion 22 on the output side is disposed so as to be closer to the arm 500 than a position P at which the action line L1 of the input side angular contact ball bearing 6 intersects the outer peripheral surface of the main body portion 21 in the direction along the central axis Lc. Thus, the line of action L1 of the input side angle contact ball bearing passes through the inside of the flange portion 22.

The flange 22 is formed protruding from the tubular body 21 in a direction intersecting the central axis Lc. Therefore, the portion of the housing 2 where the flange 22 is provided is a portion having a larger thickness dimension and higher rigidity in the direction intersecting the central axis Lc of the main body 21 than the portion of the housing 2 where the flange 22 is not provided. That is, the input side angle contacts the action line L1 of the ball bearing 6 through a portion of the housing 2 where rigidity is high. Therefore, the preload acting on the input side angular contact ball bearing 6 can be received by the portion of the housing 2 having high rigidity, and deformation of the mounting portion 23 due to the preload can be suppressed.

[ action and Effect of speed reducer ]

The speed reducer 1 of the present embodiment includes a housing 2, a carrier portion 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 carrier 5, and rotatably supports the carrier 5 with respect to the housing 2.

The housing 2 has a main body portion 21 and a flange portion 22. The main body 21 accommodates the carrier 5 and the input side angular contact ball bearing 6 therein, and the input side angular contact ball bearing 6 is in contact with the inner peripheral surface of the main body 21, and the main body 21 is formed in a tubular shape. The flange portion 22 protrudes from the main body portion 21 in a direction intersecting with a direction along the central axis Lc. The main body 21 has a mounting portion 23, and the mounting portion 23 is provided so as to extend from the flange portion 22 in a direction along the axis line in contact with the outer ring 6a of the ball bearing 6 at an angle on the input side, and is attachable to the motor bracket 200.

The input side corner C1 between the flange 22 and the mounting portion 23 is disposed closer to the distal end side of the mounting portion 23 than the position P at which the line L1 of action of the input side corner contact ball bearing 6 intersects the outer peripheral surface of the main body 21.

As described above, the speed reducer 1 of the present embodiment can suppress deformation of the housing 2 due to 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 casing 2 is formed so as to protrude from the surrounding portion, deformation of the mounting portion 23 can be suppressed.

In the speed reducer 1 of the present embodiment, the casing 2 has a recess 23C, and the recess 23C is connected to the input side corner C1, and the recess 23C is formed by partially recessing the casing 2. By providing such a recess 23c, the housing 2 can be easily formed. By providing the recess 23c, the thickness dimension of the portion of the housing 2 where the recess 23c is provided is smaller than in the case where the recess 23c is not provided. In the speed reducer 1 of the present embodiment, the line of action L1 of the input side angular contact ball bearing 6 does not pass through the concave portion 23c. Therefore, the preload applied to the input side angular contact ball bearing 6 can be suppressed from strongly acting on the portion of the housing 2 where the recess 23c is provided. Therefore, according to the speed reducer 1 of the present embodiment, the recess 23c can be provided in the casing 2, and deformation of the mounting portion 23 can be suppressed. Further, the concave portion 23c may not be provided.

In the speed reducer 1 of the present embodiment, the housing 2 has a groove portion 23b formed on the outer peripheral surface of the mounting portion 23 in the circumferential direction around the central axis of the input side angular contact ball bearing 6. By providing such groove portions 23b, the O-ring 700 can be provided. By providing the groove portion 23b, the thickness dimension of the portion of the housing 2 where the groove portion 23b is provided is smaller than in the case where the groove portion 23b is not provided. In the speed reducer 1 of the present embodiment, the line of action L1 of the input side angular contact ball bearing 6 does not pass through the groove 23b. Therefore, the preload applied to the input side angular contact ball bearing 6 can be suppressed from strongly acting on the portion of the housing 2 where the groove portion 23b is provided. Therefore, according to the speed reducer 1 of the present embodiment, the groove portion 23b can be provided in the housing 2, and deformation of the mounting portion 23 can be suppressed. Further, the groove 23b may not be provided.

In the speed reducer 1 of the present embodiment, the line of action L1 of the input side angular contact ball bearing 6 is inclined with respect to the central axis Lc so as to approach the central axis Lc toward the tip end of the mounting portion 23 in the direction along the central axis Lc. Therefore, the position P at which the action line L1 intersects the peripheral 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, since the input-side corner C1 is disposed closer to the distal end side of the mounting portion 23 than the position P, the required length dimension of the flange portion 22 in the direction along the central axis Lc can be suppressed.

Examples (example)

For example, the speed reducer 1 of the above embodiment can be designed so as to satisfy the following conditions.

The inner diameter of the main body 21 is 60mm or more and less than 200 mm.

The wall thickness dimension of the mounting portion 23 is 3mm to 10 mm.

The outside diameter dimension of the input side angular contact ball bearing 6 in a state of being taken out from the inside of the main body 21 is in a range of 5 μm to 50 μm larger than the inside diameter dimension of the main body 21.

The preload applied to the input side angular contact ball bearing 6 housed in the main body 21 is 1000N to 50000N.

The inner diameter dimension of the body portion 21 is a diameter D1 (see fig. 2) of the inner space of the body portion 21 at a position where the input side angle contacts the ball bearing 6. The thickness dimension of the mounting portion 23 is a thickness dimension D2 (see fig. 3) of the mounting portion 23 in the radial direction about the central axis Lc. Further, the thickness dimension D2 is a value at a position where the concave portion 23c and the groove portion 23b are not provided. The outer diameter dimension of the input side angular contact ball bearing 6 is a diameter D3 (see fig. 2) of a circle drawn on the outer peripheral surface of the outer ring 6a of the input side angular contact ball bearing 6. In fig. 2, since the input side angular ball bearing 6 is housed in the main body 21, the diameter D1 of the internal space of the main body 21 coincides with the diameter D3 of the circle drawn on the outer peripheral surface of the outer ring 6a of the input side angular ball bearing 6.

In the speed reducer 1 of the above embodiment, the following conditions can be satisfied.

The inner diameter of the main body 21 is 200mm or more and less than 290 mm.

The wall thickness dimension of the mounting portion 23 is 7mm to 18 mm.

The outside diameter dimension of the input side angular contact ball bearing 6 in a state of being taken out from the inside of the main body 21 is in a range of 5 μm to 70 μm larger than the inside diameter dimension of the main body 21.

The preload applied to the input-side angular contact ball bearing 6 housed in the main body 21 is 15000N or more and 80000N or less.

The inner diameter dimension of the main body 21 is 290mm or more and less than 390 mm.

The wall thickness dimension of the mounting portion 23 is 14mm to 28 mm.

The outside diameter dimension of the input side angular contact ball bearing 6 in a state of being taken out from the inside of the main body 21 is in a range of 15 μm to 70 μm larger than the inside diameter dimension of the main body 21.

The preload applied to the input side angular contact ball bearing 6 housed in the main body 21 is 30000N or more and 130000N or less.

By designing the speed reducer 1 to the value shown in the present embodiment described above, the deformation amount of the mounting portion 23 can be made within the h7 tolerance range of japanese industrial standards. Thus, the speed reducer 1 can be reliably mounted to the motor bracket 200.

(embodiment 2)

Next, embodiment 2 will be described with reference to fig. 5. Fig. 5 is a partially enlarged view showing a schematic configuration of a speed reducer 1A according to embodiment 2. Note that the same reference numerals are given to the same configurations as those in embodiment 1. In the description of embodiment 2, the same names as those of embodiment 1 may be used, and the description thereof may be omitted.

As shown in fig. 5, the preload vector V can be considered to 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 contacts the radial direction of the ball bearing 6 with the center of the rolling element 6c as a starting point and is directed toward the input side, and causes deformation of the mounting portion 23.

As shown in fig. 5, in the present embodiment, the input side corner C1 is disposed closer to the distal end side of the attachment portion 23 than the position P1 where the line L2 intersects the outer peripheral surface of the main body portion 21. In the speed reducer 1A of the present embodiment, the component Vb, which is a factor of deforming the mounting portion 23, faces the flange portion 22. That is, in the speed reducer 1A of the present embodiment, the component Vb, which is a factor of deforming the mounting portion 23, of the components included in the preload vector V can be received by the portion of the casing 2 having high rigidity. Thus, deformation of the housing 2 due to the preload vector V can be further suppressed.

In the speed reducer 1A of the present embodiment, as in the speed reducer 1 of embodiment 1, deformation of the mounting portion 23 can be suppressed even if the recess portion 23c and the groove portion 23b are provided.

In the speed reducer 1A of the present embodiment, it is possible to design the speed reducer so as to satisfy the following conditions.

The inner diameter of the main body 21 is 60mm or more and less than 200 mm.

The wall thickness dimension of the mounting portion 23 is 3mm to 10 mm.

By designing the speed reducer 1A under the above-described conditions, the deformation amount of the mounting portion 23 can be made within the h7 tolerance range of japanese industrial standards.

In the speed reducer 1A of the present embodiment, too, it can be designed so as to satisfy the following conditions.

The inner diameter of the main body 21 is 200mm or more and less than 290 mm.

The wall thickness dimension of the mounting portion 23 is 7mm to 18 mm.

The wall thickness dimension of the mounting portion 23 is 14mm to 28 mm.

(embodiment 3)

Next, embodiment 3 will be described with reference to fig. 6.

Fig. 6 is a schematic configuration diagram of the coordination robot 100. In the description of the present embodiment, the vertical direction and the horizontal direction of the cooperative robot 100 are the vertical direction and the horizontal direction in a state where the cooperative robot 100 is placed on the installation surface F.

As shown in fig. 6, the coordination robot 100 (an example of a robot in the claims) includes: a base portion 101 (an example of the 1 st member or the 2 nd member in claims) mounted on the mounting surface F; a spin head 102 (an example of a 1 st member or a 2 nd member in claims) provided to the base portion 101; an arm unit 103 (an example of the 1 st member or the 2 nd member in claims) rotatably assembled to an upper portion of the spin head 102; a speed reducer (1 st speed reducer 10A, 2 nd speed reducer 10B, 3 rd speed reducer 10C) assembled to the base portion 101, the swivel head 102, and the joint portions (1 st joint portion 106a, 2 nd joint portion 106B, 3 rd joint portion 106C) of the arm unit 103; servo motors (1 st servo motor 107, 2 nd servo motor 108, 3 rd servo motor 109) as driving sources; and an end effector 110 mounted to the arm unit 103.

The spin head 102 is rotatably coupled to the base portion 101 about the 1 st rotation axis LA. The connected portion functions as the 1 st joint portion 106a. The 1 st speed reducer 10A and the 1 st servomotor 107 are assembled to the 1 st joint 106a. The 1 st rotation axis LA coincides with the up-down direction, for example.

The rotation of the 1 st servomotor 107 is transmitted to the spin head 102 via the 1 st speed reducer 10A. Thereby, the rotation head 102 is rotationally driven about the 1 st rotation axis LA with respect to the base portion 101.

The arm unit 103 is constituted by, for example, two arms (1 st arm 104, 2 nd arm 105) long in one direction. One end of the 1 st arm 104 is rotatably coupled to an upper portion of the spin head 102 about the 2 nd rotation axis LB. The connected portion functions as the 2 nd joint portion 106b. The 2 nd speed reducer 10B and the 2 nd servomotor 108 are assembled to the 2 nd joint 106B. The 2 nd rotation axis LB coincides with the horizontal direction, for example.

The rotation of the 2 nd servomotor 108 is transmitted to the 1 st arm 104 via the 2 nd speed reducer 10B. Thereby, the 1 st arm 104 is rotationally driven about the 2 nd rotation axis LB with respect to the spin head 102. For example, the 1 st arm 104 is driven to swing in the front-rear direction with respect to the base portion 101

One end of the 2 nd arm 105 is rotatably connected to the other end of the 1 st arm 104 about the 3 rd rotation axis LC. The connected portion functions as the 3 rd joint portion 106c. The 3 rd speed reducer 10C and the 3 rd servomotor 109 are assembled to the 3 rd joint portion 106C. The 3 rd rotation axis LC coincides with the horizontal direction, for example.

The rotation of the 3 rd servomotor 109 is transmitted to the 2 nd arm 105 via the 3 rd speed reducer 10C. Thereby, the 2 nd arm 105 is rotationally driven about the 3 rd rotation axis LC with respect to the 1 st arm 104. For example, the 2 nd arm 105 is driven to swing in the up-down direction with respect to the 1 st arm 104.

An end effector 110 is mounted to the other end of arm 2 105. The end effector 110 is driven three-dimensionally by driving the spin head 102, the 1 st arm 104, and the 2 nd arm 105.

The 1 st speed reducer 10A, the 2 nd speed reducer 10B, and the 3 rd speed reducer 10C of the cooperative robot 100 according to the present embodiment are each constituted by the speed reducer 1 according to the 1 st embodiment or the speed reducer 1A according to the 2 nd embodiment.

Therefore, the cooperative robot 100 according to the present embodiment is a robot in which deformation of the mounting portion 23 of the 1 st speed reducer 10A, the 2 nd speed reducer 10B, and the 3 rd speed reducer 10C is suppressed. Either one or both of the 1 st speed reducer 10A, the 2 nd speed reducer 10B, and the 3 rd speed reducer 10C may be constituted by the speed reducer 1 of the 1 st embodiment or the speed reducer 1A of the 2 nd embodiment. The speed reducers (1 st speed reducer 10A, 2 nd speed reducer 10B, 3 rd speed reducer 10C) are mounted with, for example, servo motors (1 st servo motor 107, 2 nd servo motor 108, 3 rd servo motor 109) as target members. The speed reducers (1 st speed reducer 10A, 2 nd speed reducer 10B, 3 rd speed reducer 10C) may be mounted on a target member such as a motor bracket, not shown.

The present invention is not limited to the above-described embodiments, and various modifications are possible to the above-described embodiments without departing from the spirit of the present invention.

For example, in the above embodiment, the following cases are explained: as an example of the robot, the coordinated robot 100 is provided with 3 speed reducers (1 st speed reducer 10A, 2 nd speed reducer 10B, and 3 rd speed reducer 10C) in the coordinated robot 100. However, it is not limited thereto. The structure is as follows: for example, the robot has two members (1 st member, 2 nd member), a speed reducer is provided between the two members, and the 2 nd member of the two members rotates with respect to the 1 st member. The configuration of the above-described embodiment can be applied to various robots having such a configuration.

In the above-described embodiment, the speed reducer is described as an example of the rotation mechanism. However, the rotation mechanism is not limited to these. The structure of the above-described embodiment can be applied to various rotation mechanisms including: a housing; a rotating body; and a bearing which is located between the housing and the rotating body and which supports the rotating body rotatably with respect to the housing. That is, 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 bearings.

In the above embodiment, the mounting portion 23 provided to the housing 2 is formed so as to protrude 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 a far side where the input side angle contacts the ball bearing 6.

In the embodiment disclosed in the present specification, a member composed of a plurality of objects may be integrated with the plurality of objects, but conversely, a member composed of one object may be divided into a plurality of objects. Whether or not integrated, the present invention may be constructed so as to achieve the object of the present invention.

Claims

1. A rotation mechanism is provided with:

a housing;

a rotating body; and

a bearing provided between the housing and the rotating body and rotatably supporting the rotating body with respect to the housing,

the housing has:

a cylindrical main body portion that accommodates the rotating body and the bearing therein, and the bearing is in contact with an inner peripheral surface of the main body portion; and

a flange portion disposed from the main body portion in a direction intersecting a direction along an axis of the main body portion,

the main body portion has an attachment portion provided in a direction along the axis from the flange portion and attachable to a subject member,

The corner between the flange portion and the mounting portion is disposed so as to be located closer to the distal end side of the mounting portion than a position where the line of action of the bearing intersects the outer peripheral surface of the main body portion.

2. The rotary mechanism according to claim 1, wherein,

the mounting portion is provided so as to extend from the flange portion in a direction along the axis with respect to an outer ring of the bearing.

3. The rotary mechanism according to claim 1 or 2, wherein,

the bearing is an angular contact ball bearing,

the corner portion is disposed so as to be located closer to the tip end side of the mounting portion than a position where a line, which is orthogonal to the center 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.

4. The rotary mechanism according to claim 1 or 2, wherein,

the housing has a recess connected to the corner, and the recess is formed by partially recessing the housing.

5. The rotary mechanism according to claim 1 or 2, wherein,

the housing has a groove portion formed on an outer peripheral surface of the mounting portion along a circumferential direction centering on a central axis of the bearing.

6. The rotary mechanism according to claim 1 or 2, wherein,

the action line is inclined with respect to the axis in such a manner as to approach the axis in a direction along the axis of the main body portion toward a tip end of the mounting portion.

7. The rotary mechanism according to claim 3, wherein,

the inner diameter of the main body is 60mm or more and less than 200mm,

the wall thickness of the mounting part is 3mm or more and 10mm or less,

the outer diameter dimension of the angular ball bearing in a state of being taken out from the inside of the main body is in a range of 5 μm to 50 μm,

the preload applied to the angular ball bearing housed in the main body is 1000N to 50000N.

8. The rotary mechanism according to claim 3, wherein,

the inner diameter of the main body is 200mm or more and less than 290mm,

the wall thickness of the mounting part is 7mm or more and 18mm or less,

the outer diameter dimension of the angular ball bearing in a state of being taken out from the inside of the main body is in a range of 5 μm to 70 μm larger than the inner diameter dimension of the main body,

The preload applied to the angular ball bearing housed in the main body is 15000N or more and 80000N or less.

9. The rotary mechanism according to claim 3, wherein,

the inner diameter of the main body is 290mm or more and less than 390mm,

the wall thickness of the mounting part is 14mm or more and 28mm or less,

the outer diameter dimension of the angular ball bearing in a state of being taken out from the inside of the main body is larger than the inner diameter dimension of the main body by a range of 15 μm to 70 μm,

the preload applied to the angular ball bearing housed in the main body is 30000N to 130000N.

10. A rotation mechanism is provided with:

a housing;

a rotating body; and

an angular ball bearing which is located between the housing and the rotating body and which rotatably supports the rotating body with respect to the housing,

the housing has:

a cylindrical main body portion that houses the rotating body and the angular ball bearing therein, and the angular ball bearing is in contact with an inner peripheral surface of the main body portion; and

a flange portion protruding from the main body portion in a direction intersecting with a direction along an axis of the main body portion,

The main body portion has an attachment portion that is provided so as to extend from the flange portion in a direction along the axis with respect to an outer ring of the angular ball bearing, and is attachable to an object member,

the action line of the angular ball bearing is inclined with respect to the axis in such a manner as to approach the axis in a direction along the axis of the main body portion toward the tip end of the mounting portion,

the corner between the flange portion and the mounting portion is disposed so as to be located on the tip end side of the mounting portion than a position where a line, which is orthogonal to the center 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,

the housing further has:

a recess portion connected to the corner portion, the recess portion being formed by partially recessing the housing; and

a groove portion formed on an outer peripheral surface of the mounting portion along a circumferential direction centering on a central axis of the angular ball bearing,

the inner diameter of the main body is 60mm or more and less than 200mm,

the wall thickness of the mounting part is 3mm or more and 10mm or less,

11. A rotation mechanism is provided with:

a housing;

a rotating body; and

the housing has:

the housing further has:

the inner diameter of the main body is 200mm or more and less than 290mm,

the wall thickness of the mounting part is 7mm or more and 18mm or less,

12. A rotation mechanism is provided with:

a housing;

a rotating body; and

The housing has:

the housing further has:

the inner diameter of the main body is 290mm or more and less than 390mm,

the wall thickness of the mounting part is 14mm or more and 28mm or less,

13. A robot is provided with:

1 st component;

a 2 nd member; and

a rotation mechanism provided between the 1 st member and the 2 nd member, for connecting the 2 nd member to rotate relative to the 1 st member,

the rotation mechanism is provided with:

a housing;

a rotating body; and

the housing has: