Ball bearing with outer ring guide retainer, and eccentric rotation device

Abstract

The present invention provides a ball bearing with an outer ring guide retainer, in which a crown-shaped resin retainer (4) has an annular portion (11) disposed so as to face the inside of one outer ring groove shoulder portion (9) in the radial direction, and a plurality of cantilevered column portions (12) extending in the axial direction from the annular portion (11), an outer ring guide surface (17) is provided on the outer periphery of the annular portion (11), and the outer ring guide surface (17) is provided on the outer periphery of the outer ring groove shoulder portion (9). The outer ring guide surface (17) is in sliding contact with one outer ring groove shoulder part (9), and each column part (12) is provided with an outer ring guide protrusion (15) in sliding contact with the other outer ring groove shoulder part (10).

Description

Technical Field

[0001] The present invention relates to a ball bearing with an outer ring guide retainer and an eccentric rotating device using the ball bearing. Background Art

[0002] As bearings for supporting rotating shafts, ball bearings are mostly used. The ball bearings have an inner ring, an outer ring coaxially arranged radially outside the inner ring, a plurality of balls assembled between the inner ring and the outer ring, and a retainer for retaining the plurality of balls. An outer ring raceway groove for rolling contact of the balls and a pair of outer ring groove shoulders located on both axial sides of the outer ring raceway groove are provided on the inner circumference of the outer ring (for example, Patent Documents 1 to 5).

[0003] As a retainer used for the ball bearing, a crown-shaped resin retainer is known (Patent Documents 1 to 4). The crown-shaped resin retainer has: an annular portion, which is arranged radially opposite to the inner side of one of the pair of outer ring groove shoulders on the inner circumference of the outer ring; and a plurality of cantilever beam-shaped column portions, which extend axially from the annular portion at intervals in the circumferential direction. Pockets for accommodating a plurality of balls are formed between the circumferentially adjacent column portions. Compared with ball bearings using metal retainers, ball bearings using crown-shaped resin retainers have the advantages of being light, having low torque, and having low noise.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2002-295480

[0005] Patent Document 2: Japanese Patent Application Publication No. 2007-056930

[0006] Patent Document 3: Japanese Patent Application Publication No. 2007-292093

[0007] Patent Document 4: Japanese Patent Application Publication No. 2017-116008

[0008] Patent Document 5: Japanese Patent Application No. 2007-506059

[0009] The inventor of the present application studied the installation of a ball bearing on an eccentric shaft of an eccentric rotating device and the use of a crown-shaped resin retainer as the retainer of the ball bearing. As a result, when a ball guide method is used as the guide method of a crown-shaped resin retainer (hereinafter referred to as "retainer") of a ball bearing installed on an eccentric shaft, the retainer contacts only a part of the balls with a high surface pressure, which may cause the oil film on the surface of the balls to break and the retainer to be damaged. On the other hand, it is known that when an outer ring guide method is used as the guide method of the retainer, due to the tilt of the retainer caused by the centrifugal force accompanying the eccentric rotation, there is a concern that the outer periphery of the column portion located in the eccentric direction will collide with the outer ring groove shoulder and the cross edge of the outer ring raceway groove. The following is an explanation.

[0010] Fig.13 An example of an eccentric rotating device is shown. The eccentric rotating device has a rotating shaft 30 of an electric motor, a main shaft portion 31 and an eccentric shaft portion 32 which are integrally provided with the rotating shaft 30. The main shaft portion 31 has a cylindrical outer periphery centered at the same position as the rotation center C0 of the rotating shaft 30. A main bearing 33 is mounted on the outer periphery of the main shaft portion 31, and the main bearing 33 rotatably supports the main shaft portion 31 at a fixed position. The eccentric shaft portion 32 has a cylindrical outer periphery centered at a position C1 which is eccentric from the rotation center C0 of the rotating shaft 30 by a predetermined eccentricity e. A ball bearing 34 is mounted on the outer periphery of the eccentric shaft portion 32. An eccentric rotating component (for example, a swirling scroll of a scroll compressor) not shown in the figure is mounted on the outer periphery of the ball bearing 34.

[0011] The ball bearing 34 includes an inner ring 35, an outer ring 36 coaxially disposed radially outside the inner ring 35, a plurality of balls 37 assembled between the inner ring 35 and the outer ring 36, and a retainer 38 retaining the plurality of balls 37. An outer ring raceway groove 39 with which the balls 37 roll and contact is provided on the inner periphery of the outer ring 36, and a pair of outer ring groove shoulders 40 and 41 located on both axial sides of the outer ring raceway groove 39. The retainer 38 includes an annular portion 42 disposed opposite to the radial inner side of the outer ring groove shoulder 40 of one of the pair of outer ring groove shoulders 40 and 41 on the inner periphery of the outer ring 36, and a plurality of cantilever beam-like columnar portions 43 extending axially from the annular portion 42 at intervals in the circumferential direction.

[0012] In the eccentric rotation device, when the rotating shaft 30 of the electric motor rotates, the main shaft portion 31 rotates at a fixed position, and the eccentric shaft portion 32 rotates eccentrically with a radius of eccentricity e around the rotation center C0 of the rotating shaft 30. At this time, the retainer 38 of the ball bearing 34 rotates eccentrically with a radius of eccentricity e around the rotation center C0 of the rotating shaft 30. Therefore, unlike the retainer 44 of the main bearing 33 rotating at a fixed position, an eccentric direction (the direction in which the center C1 of the eccentric shaft portion 32 is relative to the rotation center C0) based on the eccentric rotation is generated in the retainer 38. Fig.13 , Fig.14 In addition, each ball 37 of the ball bearing 34 also generates a centrifugal force in the eccentric direction, so the retainer 38 is also subjected to a force in the eccentric direction from these balls 37.

[0013] Therefore, if a ball guide method (a method of positioning the retainer 38 in the radial direction by bringing the inner surface of the pocket of the retainer 38 into contact with the surface of the ball 37) which is a general method is adopted as a guide method for the retainer 38, the retainer 38 will only contact a part of the balls 37 at a high surface pressure, and the lubricant on the surface of the balls 37 will be scraped off by this contact, thereby causing the oil film on the surface of the balls 37 to break, and there is a concern that peeling and seizing will occur due to poor lubrication. In addition, if a ball guide method is adopted, the retainer 38 will only contact a part of the balls 37 at a high surface pressure, thereby generating a high stress in the retainer 38, and there is also a concern that the retainer 38 will be damaged.

[0014] Therefore, the inventors of the present application have studied a guide method for the retainer 38 as the ball bearing 34 mounted on the eccentric shaft portion 32, such as Figure 13 to Figure 15 As shown, the case of adopting an outer ring guide method (a method of positioning the retainer 38 in the radial direction by making the outer periphery of the retainer 38 contact the inner periphery of the outer ring groove shoulder 40) as in Patent Documents 1 to 4. If the outer ring guide method is adopted, the retainer 38 is positioned by contacting the inner periphery of the outer ring groove shoulder 40 instead of being positioned by contacting the surface of the ball 37, so when an eccentric centrifugal force is generated in the retainer 38 and the ball 37, it is possible to prevent the retainer 38 from contacting only a part of the ball 37 with a high surface pressure.

[0015] However, when an outer ring guide method is adopted as a guide method for the retainer 38 of the ball bearing 34 installed on the eccentric shaft portion 32, it is known that due to the inclination of the retainer 38 caused by the centrifugal force accompanying the eccentric rotation, there is a concern that the outer periphery of the column portion 43 located in the eccentric direction will collide with the intersection edge of the outer ring groove shoulder portion 40 and the outer ring raceway groove 39.

[0016] That is, Fig.16 As shown in FIG. 1 , in the case of an outer ring guide method in which the outer periphery of the retainer 38 is brought into contact with the inner periphery of the outer ring groove shoulder 40 to position the retainer 38 in the radial direction, if the retainer 38 rotates eccentrically, the centrifugal force generated in the retainer 38 and the balls 37 accompanying the eccentric rotation will cause the retainer 38 to move in the eccentric direction (in the direction of the outer ring). Fig.14 The middle is the upward direction, Fig.16 The retainer 38 is supported by only the outer ring groove shoulder 40 of the pair of outer ring groove shoulders 40 and 41 (i.e., the retainer 38 is cantilever supported), so the retainer 38 is tilted. In addition, it is known that due to the tilt of the retainer 38, the outer periphery of the column portion 43 located in the eccentric direction collides with the intersecting edge of the outer ring groove shoulder 40 and the outer ring raceway groove 39, and there is a concern that the retainer 38 may be worn and the strength may be reduced, or the friction torque of the bearing may increase due to the edge collision. Summary of the invention

[0017] The problem to be solved by the present invention is to provide a ball bearing that can prevent the retainer from contacting only a part of the balls with a high surface pressure when centrifugal force accompanying eccentric rotation is generated, or from colliding with the outer periphery of the column portion located in the eccentric direction and the intersection edge of the outer ring groove shoulder and the outer ring raceway groove due to the inclination of the retainer.

[0018] In order to solve the above-mentioned problems, the present invention provides a ball bearing with an outer ring guide cage having the following structure.

[0019] [Structure 1]

[0020] A ball bearing with an outer ring guide retainer, comprising:

[0021] Inner circle;

[0022] An outer ring, which is coaxially arranged radially outside the inner ring;

[0023] a plurality of balls assembled between the inner ring and the outer ring; and

[0024] a crown-shaped resin retainer that retains the plurality of balls,

[0025] The inner circumference of the outer ring is provided with an outer ring raceway groove for rolling contact with the balls, and a pair of outer ring groove shoulders located on both axial sides of the outer ring raceway groove.

[0026] The crown-shaped resin retainer comprises an annular portion disposed radially opposite to the inner side of one of the pair of outer race groove shoulders, and a plurality of cantilever beam-like column portions extending axially from the annular portion at intervals in the circumferential direction.

[0027] An outer ring guide surface is provided on the outer periphery of the annular portion to be in sliding contact with the outer ring groove shoulder portion of the one side.

[0028] The above-mentioned ball bearing with outer ring guide retainer is characterized in that:

[0029] Each of the column portions has an outer ring guide protrusion that is in sliding contact with the other outer ring groove shoulder portion of the pair of outer ring groove shoulder portions.

[0030] Accordingly, since the outer ring guide method is adopted as the guide method of the crown-shaped resin retainer, when the centrifugal force accompanying the eccentric rotation is generated in the crown-shaped resin retainer and the ball, it is possible to prevent the crown-shaped resin retainer from contacting only a part of the balls with a high surface pressure. In addition, an outer ring guide surface is provided on the outer periphery of the annular portion of the crown-shaped resin retainer, and the outer ring guide surface is in sliding contact with one of the outer ring groove shoulders of a pair of outer ring groove shoulders located on both axial sides of the outer ring raceway groove, and an outer ring guide protrusion is provided on each column portion to be in sliding contact with the other outer ring groove shoulder. Therefore, when the crown-shaped resin retainer is radially moved in the eccentric direction due to the centrifugal force generated in the crown-shaped resin retainer and the ball accompanying the eccentric rotation, the crown-shaped resin retainer is in a state of being supported by both the pair of outer ring groove shoulders on both axial sides of the outer ring raceway groove. Therefore, when centrifugal force accompanying eccentric rotation is generated in the crown-shaped resin retainer and the ball, the crown-shaped resin retainer is not easy to tilt, and the outer periphery of the column portion located in the eccentric direction can be prevented from colliding with the outer ring groove shoulder and the intersection edge of the outer ring raceway groove.

[0031] [Structure 2]

[0032] According to the ball bearing with outer ring guide retainer described in structure 1,

[0033] Each of the column portions further comprises a pair of ball retaining claws extending axially at intervals in the circumferential direction, and a separation groove separating the pair of ball retaining claws from the outer ring guide protrusion in such a manner that the pair of ball retaining claws can be deformed circumferentially independently from the outer ring guide protrusion.

[0034] According to this, since the separation groove is provided to separate the pair of ball holding claws from the outer ring guide protrusion, when the ball is inserted into the pocket between the circumferentially adjacent column parts, the ball holding claws are elastically deformed smoothly. Therefore, the assembly operation of the ball bearing is easy.

[0035] [Structure 3]

[0036] According to the ball bearing with outer ring guide retainer described in structure 2, wherein:

[0037] The pair of ball retaining claws are arranged opposite to the radial inner side of the outer ring guide protrusion.

[0038] The separation groove is formed to extend in the circumferential direction between the pair of ball holding claws and the outer ring guide protrusion so as to separate the pair of ball holding claws from the outer ring guide protrusion in the radial direction.

[0039] According to this, since a pair of ball retaining claws are arranged opposite to the radial inner side of the outer ring guide protrusion, the circumferential width of the outer ring guide protrusion can be set larger. Therefore, by increasing the contact area between the crown-shaped resin retainer and the outer ring, the durability of the crown-shaped resin retainer can be effectively improved.

[0040] [Structure 4]

[0041] A ball bearing with an outer ring guide retainer according to any one of configurations 1 to 3, wherein:

[0042] A second outer ring guide surface is provided on the outer periphery of the outer ring guide protrusion, which is in sliding contact with the other outer ring groove shoulder portion.

[0043] An R chamfered portion with an arc-shaped cross section smoothly connected to the second outer ring guide surface or a C chamfered portion intersecting the second outer ring guide surface at an obtuse angle is provided at both ends in the circumferential direction of the second outer ring guide surface.

[0044] Accordingly, since an R chamfered portion with a circular arc shape in cross section smoothly connected to the second outer ring guide surface or a C chamfered portion intersecting the second outer ring guide surface at an obtuse angle is provided at both circumferential ends of the second outer ring guide surface of the outer ring guide projection, when the crown-shaped resin retainer moves in the eccentric direction due to the centrifugal force accompanying the eccentric rotation, and the second outer ring guide surface of the outer ring guide projection slides in contact with the outer ring groove shoulder, the lubricant on the inner circumference of the outer ring groove shoulder is also difficult to be scraped off by the circumferential end edge of the second outer ring guide surface. Therefore, the lubricity between the second outer ring guide surface of the outer ring guide projection and the inner circumference of the outer ring groove shoulder can be well maintained.

[0045] [Structure 5]

[0046] A ball bearing with an outer ring guide retainer according to any one of configurations 1 to 4, wherein:

[0047] Pockets for accommodating the plurality of balls are formed between the circumferentially adjacent column portions.

[0048] The inner surface of the pocket is formed in a cylindrical shape extending in the radial direction.

[0049] According to this, when the crown-shaped resin cage moves in the eccentric direction due to the centrifugal force accompanying the eccentric rotation, it is possible to reliably prevent the inner surface of the pocket of the crown-shaped resin cage from interfering with the ball.

[0050] [Structure 6]

[0051] According to the ball bearing with outer ring guide retainer described in structure 5,

[0052] The distance between the front ends of the outer ring guide protrusions located on both sides in the circumferential direction with the ball interposed therebetween is set to be equal to or larger than the inner diameter of the inner surface of the pocket.

[0053] Accordingly, since the interval between the front ends of the outer ring guide protrusions is set to be the same as or larger than the inner diameter of the inner surface of the pocket, interference between the ball and the outer ring guide protrusion can be reliably prevented when the ball is inserted into the pocket.

[0054] [Structure 7]

[0055] A ball bearing with an outer ring guide retainer according to any one of configurations 1 to 4, wherein:

[0056] Pockets for accommodating the plurality of balls are formed between the circumferentially adjacent column portions.

[0057] The inner surface of the pocket is formed into a spherical shape along the surface of the ball.

[0058] The opening of the pocket toward the outer periphery of the crown-shaped resin retainer has a semicircular arc edge portion open in the axial direction.

[0059] The distance between the front ends of the outer ring guide protrusions located on both sides in the circumferential direction across the ball is set to be equal to or larger than the arc diameter of the arc edge portion.

[0060] Accordingly, since the spacing between the front ends of the outer ring guide protrusions is set to be the same as or larger than the arc diameter of the arc edge of the pocket opening to the outer periphery of the crown-shaped resin retainer, the ball can be reliably prevented from interfering with the outer ring guide protrusion when the ball is inserted into the pocket.

[0061] [Structure 8]

[0062] A ball bearing with an outer ring guide retainer according to structure 2 or 3, wherein:

[0063] The distance between the front ends of the ball holding claws that face each other in the circumferential direction with the ball sandwiched therebetween is set to be not less than 80% and not more than 92% of the diameter of the ball.

[0064] Furthermore, in the present invention, the following structure is also provided as an eccentric rotation device using a ball bearing with an outer ring guide cage having the above-mentioned structure.

[0065] An eccentric rotating device, comprising:

[0066] a rotary shaft, which rotates in a fixed position;

[0067] an eccentric shaft portion having a cylindrical outer periphery centered at a position eccentric from the rotation center of the rotation shaft and eccentrically rotating about the rotation center of the rotation shaft; and

[0068] The ball bearing with an outer ring guide retainer according to any one of Structures 1 to 8 is mounted on the outer periphery of the eccentric shaft portion.

[0069] The ball bearing with an outer ring guide retainer of the present invention adopts an outer ring guide method as a guide method for the crown-shaped resin retainer, so when the centrifugal force accompanying the eccentric rotation is generated in the crown-shaped resin retainer and the ball, it is possible to prevent the crown-shaped resin retainer from contacting only a part of the ball with a high surface pressure. In addition, an outer ring guide surface is provided on the outer periphery of the annular portion of the crown-shaped resin retainer, and the outer ring guide surface is in sliding contact with one of the outer ring groove shoulders of a pair of outer ring groove shoulders located on both axial sides of the outer ring raceway groove, and an outer ring guide protrusion is provided on each column portion to be in sliding contact with the other outer ring groove shoulder, so that when the crown-shaped resin retainer is radially moved in the eccentric direction due to the centrifugal force generated in the crown-shaped resin retainer and the ball accompanying the eccentric rotation, the crown-shaped resin retainer is in a state of being supported by both the pair of outer ring groove shoulders on both axial sides of the outer ring raceway groove. Therefore, when centrifugal force accompanying eccentric rotation is generated in the crown-shaped resin retainer and the ball, the crown-shaped resin retainer is not easy to tilt, and the outer periphery of the column portion located in the eccentric direction can be prevented from colliding with the outer ring groove shoulder and the intersection edge of the outer ring raceway groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 It is a cross-sectional view showing a ball bearing with an outer ring guide cage according to a first embodiment of the present invention.

[0071] Figure 2 It is viewed from the other side of the axis (right side in the figure). Figure 1 Partial cross-sectional view of a ball bearing.

[0072] Figure 3 Yes Figure 2 An enlarged view of a portion of a crown-shaped resin cage and the vicinity of a ball.

[0073] Figure 4 It means to make Figure 1 A cross-sectional view showing a state in which the outer periphery of the crown-shaped resin retainer is in sliding contact with a pair of outer ring groove shoulders due to the eccentric rotation of the ball bearing and the centrifugal force accompanying the eccentric rotation causing the crown-shaped resin retainer to move radially in the eccentric direction (downward in the figure).

[0074] Figure 5 It is along Figure 4 A cross-sectional view of line VV.

[0075] Figure 6 Yes means Figure 2 Figure 1. Crown-shaped resin retainer.

[0076] Figure 7 It is along Figure 6 A cross-sectional view taken along line VII-VII.

[0077] Figure 8 Observed from the radial outside Figure 6 Figure 1. Crown-shaped resin retainer.

[0078] Fig. 9 yes Figure 6 Stereoscopic view of a crown-shaped resin retainer.

[0079] Fig.10 is with Figure 2 The figures correspondingly show the second embodiment of the present invention.

[0080] Fig.11 Yes Fig.10 An enlarged view of a portion of a crown-shaped resin cage and the vicinity of a ball.

[0081] Fig.12 yes Fig.10 Stereoscopic view of a crown-shaped resin retainer.

[0082] Fig.13 It is a cross-sectional view showing the eccentric rotating device.

[0083] Fig.14 It is along Fig.13 A cross-sectional view of line XIV-XIV.

[0084] Fig.15 Yes Fig.14 An enlarged view of the vicinity of the ball in the eccentric direction (upward in the figure).

[0085] Fig.16 is with Figure 4 Correspondingly, Fig.13 The crown-shaped resin retainer of the comparative example shown in FIG. 1 is eccentrically rotated due to the centrifugal force (in the Fig.16 A cross-sectional view showing a state in which the outer periphery of the crown-shaped resin retainer is in sliding contact with the outer ring groove shoulder on the axial side due to radial movement of the retainer (with the lower side in the center). DETAILED DESCRIPTION

[0086] Figure 1 A ball bearing with an outer ring guide retainer according to a first embodiment of the present invention is shown. The ball bearing comprises: an inner ring 1; an outer ring 2 coaxially disposed radially outside the inner ring 1; a plurality of balls 3 assembled between the inner ring 1 and the outer ring 2 at intervals in the circumferential direction; and a crown-shaped resin retainer 4 (hereinafter referred to as "retainer 4") that retains the plurality of balls 3. The ball bearing is used in a lubricating environment of lubricating oil or grease.

[0087] An inner ring raceway groove 5 with which the balls 3 roll and contact is formed on the outer periphery of the inner ring 1, and a pair of inner ring groove shoulders 6, 7 located axially outside the inner ring raceway groove 5. The inner ring raceway groove 5 is formed to extend circumferentially at the axial center of the outer periphery of the inner ring 1. The pair of inner ring groove shoulders 6, 7 are formed to extend circumferentially on both sides of the inner ring raceway groove 5 in the axial direction.

[0088] The outer ring 2 has an outer ring raceway groove 8 for rolling contact with the balls 3 and a pair of outer ring groove shoulders 9 and 10 located axially outside the outer ring raceway groove 8. The outer ring raceway groove 8 is formed to extend circumferentially at the axial center of the inner circumference of the outer ring 2. The pair of outer ring groove shoulders 9 and 10 are formed to extend circumferentially on both axial sides of the outer ring raceway groove 8. The inner circumferences of the pair of outer ring groove shoulders 9 and 10 are both cylindrical surfaces whose inner diameters do not change in the axial direction and are constant. The inner diameter of the outer ring groove shoulder 9 is the same as the inner diameter of the outer ring groove shoulder 10.

[0089] The ball 3 is sandwiched radially between the inner ring raceway groove 5 and the outer ring raceway groove 8. The ball bearing is a deep groove ball bearing. That is, the inner ring raceway groove 5 is an arc groove having an axially symmetrical concave arc-shaped cross section, and the outer ring raceway groove 8 is also an arc groove having an axially symmetrical concave arc-shaped cross section.

[0090] The retainer 4 includes: an annular portion 11 disposed opposite to the radial inner side of the outer ring groove shoulder portion 9; and a column portion 12 extending axially from the annular portion 11 between the circumferentially adjacent balls 3. The column portion 12 is formed in a cantilever beam shape with one axial end as a fixed end fixed to the annular portion 11 and the other axial end as a free end. A plurality of column portions 12 are provided at intervals in the circumferential direction. Pockets 13 for accommodating the balls 3 are formed between the circumferentially adjacent column portions 12.

[0091] like Figure 6 , Figure 7 , Fig. 9 As shown, each column 12 is formed into a three-pronged shape having a column base 14 extending axially from the annular portion 11, three outer ring guide protrusions 15 branching from the front end of the column base 14 and extending axially, and a pair of ball retaining claws 16. Figure 1 As shown, the outer ring guide protrusion 15 is an axial protrusion that is in sliding contact with the inner circumference of the outer ring groove shoulder 10. The ball holding claw 16 is a claw that holds the ball 3 so that the ball 3 does not fall out of the pocket 13 in the axial direction.

[0092] The annular portion 11 and each column portion 12 are seamlessly formed as a whole by a resin composition in which a fiber-reinforced material is added to a resin material. As a resin material serving as a basis for the resin composition, polyamide (PA) or super engineering plastics can be used. As polyamide, polyamide 46 (PA46), polyamide 66 (PA66), poly-1,9-nonyl terephthalamide (PA9T), etc. can be used. In addition, as super engineering plastics, polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) can be used. As a fiber-reinforced material added to the resin material, glass fiber, carbon fiber, aramid fiber, etc. can be used. The fiber-reinforced material is mixed in a ratio of 10 to 50 weight % of the resin composition forming the retainer 4.

[0093] like Figure 1 As shown, the annular portion 11 is an annular portion extending in the circumferential direction on one side of the axial direction of the ball 3. An outer ring guide surface 17 is provided on the outer periphery of the annular portion 11 to be in sliding contact with the outer ring groove shoulder portion 9. The outer ring guide surface 17 is a cylindrical surface whose outer diameter does not change in the axial direction but is constant. The outer ring guide surface 17 is opposite to the radial inner side of the outer ring groove shoulder portion 9 with a small gap (for example, a gap with a radius of 0.5 mm or less).

[0094] The surface of the column base 14 facing the ball 3 and the surface of the ball holding claw 16 facing the ball 3 form the inner surface of the pocket 13 for accommodating the ball 3. Figure 1 The inner surface of the pocket 13 is a cylindrical surface extending in the radial direction. The axial length of the column base 14 (the axial distance from the bottom of the pocket 13 to the boundary between the column base 14 and the ball retaining claw 16) is set to be larger than the radius of the ball 3.

[0095] A second outer ring guide surface 18 that is in sliding contact with the outer ring groove shoulder 10 is provided on the outer periphery of the axial end of the outer ring guide protrusion 15 on the side away from the annular portion 11. The second outer ring guide surface 18 is a cylindrical surface whose outer diameter does not change along the axial direction and is constant. The second outer ring guide surface 18 is opposite to the radial inner side of the outer ring groove shoulder 10 with a small gap (for example, a gap with a radius of less than 0.5 mm). The outer diameter of the second outer ring guide surface 18 is the same as the outer diameter of the outer ring guide surface 17 on the outer periphery of the annular portion 11. Figure 3 , Figure 8 As shown, the side surfaces 19 on both axial sides of the outer ring guide protrusion 15 are formed into a flat surface connected to the cylindrical inner surface of the pocket 13 .

[0096] like Figure 6 , Figure 8As shown, at both circumferential ends of the second outer ring guide surface 18 (the intersection edges between the second outer ring guide surface 18 and the side surfaces 19 on both axial sides of the outer ring guide protrusion 15), R chamfered portions 20 with arc-shaped cross sections are provided, and the R chamfered portions 20 are smoothly connected to the second outer ring guide surface 18. Instead of the R chamfered portions 20, C chamfered portions intersecting the second outer ring guide surface 18 at an obtuse angle may be provided. Figure 8 , Fig. 9 As shown, the rounded chamfered portion 20 is formed on the entire opening edge of the pocket 13 toward the outer periphery of the retainer 4 .

[0097] like Figure 2 , Figure 3 As shown, each column portion 12 has a pair of ball retaining claws 16 spaced apart in the circumferential direction. Figure 3 As shown, among a pair of column portions 12 located on both sides of the circumference with the ball 3 separated therefrom, the ball retaining claw 16 on the other circumferential side (the right side in the figure) of the column portion 12 located on one circumferential side (the left side in the figure) of the ball 3, and the ball retaining claw 16 on one circumferential side (the left side in the figure) of the column portion 12 located on the other circumferential side (the right side in the figure) of the ball 3 sandwich the ball 3 in the middle and are circumferentially opposed, holding the ball 3 from both sides of the circumference.

[0098] like Figure 6 , Figure 7 As shown, in each column portion 12, a pair of ball retaining claws 16 are arranged opposite to the radial inner side of the outer ring guide protrusion 15. A separation groove 21 is formed between each ball retaining claw 16 and the outer ring guide protrusion 15, and the separation groove 21 separates the ball retaining claw 16 from the outer ring guide protrusion 15. By providing the separation groove 21, the ball retaining claw 16 is separated from the outer ring guide protrusion 15, and the ball retaining claw 16 can be elastically deformed in the circumferential direction independently from the outer ring guide protrusion 15. In the figure, the separation groove 21 is a circumferential groove extending in the circumferential direction between the pair of ball retaining claws 16 and the outer ring guide protrusion 15, so as to separate the pair of ball retaining claws 16 from the outer ring guide protrusion 15 in the radial direction.

[0099] like Figure 8 As shown, the opening of the pocket 13 toward the outer periphery of the retainer 4 has a semicircular arc edge 22 that is open in the axial direction. Figure 3 ) The distance a between the front ends of the outer ring guide protrusions 15 located on both sides in the circumferential direction is set to be equal to or larger than the arc diameter b of the arc edge 22 (in the present embodiment, the arc diameter b of the arc edge 22 is the same as the inner diameter of the cylindrical inner surface of the pocket 13). In addition, the distance c between the front ends of the ball retaining claws 16 sandwiching the ball 3 and facing each other in the circumferential direction is set to be equal to the distance between the ball 3 (refer to Figure 3 ) is more than 80% and less than 92% of the diameter. Figure 5As shown, the size of the circumferential gap δ between the ball 3 and the inner surface of the pocket 13 is set to be not less than 0.2 mm and not more than 0.5 mm.

[0100] The ball bearing can be assembled as follows. First, prepare Figure 1 The inner ring 1, outer ring 2 and multiple balls 3 are shown, and multiple balls 3 are assembled between the inner ring 1 and the outer ring 2. Next, the circumferential position of the balls 3 is adjusted so that the multiple balls 3 are equally spaced in the circumferential direction. Thereafter, the retainer 4 is pressed into the space between the inner ring 1 and the outer ring 2 in the axial direction. At this time, the ball retaining claws 16 are pressed by the balls 3 and temporarily elastically deformed in the circumferential direction, and the balls 3 pass through the front ends of the ball retaining claws 16 that are enlarged due to the elastic deformation, thereby inserting the balls 3 into the pockets 13.

[0101] The ball bearing is installed in Fig.13 , Fig.14 The ball bearing of the above embodiment can be replaced by the outer periphery of the eccentric shaft portion 32 of the eccentric rotating device shown in FIG. Fig.13 , Fig.14 The ball bearing 34 shown is used. Fig.13 , Fig.14 The eccentric rotating device shown includes: a rotating shaft 30 of an electric motor, which rotates at a fixed position; a main shaft portion 31, which has a cylindrical outer periphery centered at the same position as the rotation center C0 of the rotating shaft 30; an eccentric shaft portion 32, which has a cylindrical outer periphery centered at a position eccentric from the rotation center C0 of the rotating shaft 30 as a center C1; a main bearing 33, which is mounted on the outer periphery of the main shaft portion 31; and a ball bearing 34, which is mounted on the outer periphery of the eccentric shaft portion 32, and the eccentric shaft portion 32 rotates eccentrically around the rotation center C0 of the rotating shaft 30 with a radius of eccentricity e due to the rotational driving force of the rotating shaft 30.

[0102] like Figure 1 As shown, the ball bearing of this embodiment adopts an outer ring guiding method (a method of positioning the retainer 4 in the radial direction by making the outer periphery of the retainer 4 contact with the inner periphery of the outer ring 2) as a guiding method for the retainer 4, so when it is installed in Fig.13 , Fig.14 When the eccentric shaft portion 32 of the eccentric rotating device is used as shown in FIG. Figure 4 As shown, the centrifugal force accompanying the eccentric rotation can be supported by the contact portion between the outer periphery of the retainer 4 and the inner periphery of the outer ring 2. Therefore, as in the case of adopting a ball guide method (a method of positioning the retainer 4 in the radial direction by bringing the inner surface of the pocket 13 of the retainer 4 into contact with the surface of the ball 3), when the centrifugal force accompanying the eccentric rotation is generated, it is possible to prevent the retainer 4 from contacting only a part of the balls 3 with a high surface pressure.

[0103] In addition, if Figure 1As shown, the ball bearing is provided with an outer ring guide surface 17 on the outer periphery of the annular portion 11 of the retainer 4, and the outer ring guide surface 17 is in sliding contact with one of the outer ring groove shoulders 9 and 10 located on the axial sides of the outer ring raceway groove 8, and each column portion 12 is provided with an outer ring guide protrusion 15 in sliding contact with the other outer ring groove shoulder 10, so as Figure 4 As shown in FIG. 1 , the centrifugal force generated in the retainer 4 and the ball 3 accompanying the eccentric rotation causes the retainer 4 to move in the eccentric direction ( Fig.13 The center C1 of the eccentric shaft portion 32 is in the direction relative to the rotation center C0. Figure 4 When the retainer 4 moves radially (the lower side in the center), the retainer 4 is supported by a pair of outer ring groove shoulders 9 and 10 on both axial sides of the outer ring raceway groove 8. Therefore, when centrifugal force accompanying eccentric rotation is generated in the retainer 4 and the ball 3, the retainer 4 is not easy to tilt, and the outer periphery of the column 12 located in the eccentric direction can be prevented from colliding with the intersection edge of the outer ring groove shoulder 9 and the outer ring raceway groove 8.

[0104] In addition, if Figure 7 As shown, the ball bearing is provided with a separation groove 21 separating a pair of ball retaining claws 16 from the outer ring guide protrusion 15, so that when the ball 3 is inserted into the pocket 13 between the circumferentially adjacent column portions 12, the ball retaining claws 16 are elastically deformed smoothly. Therefore, the assembly operation of the ball bearing is easy.

[0105] In addition, if Figure 6 As shown, the pair of ball retaining claws 16 of the ball bearing are arranged opposite to the radial inner side of the outer ring guide protrusion 15, so the circumferential width of the outer ring guide protrusion 15 can be set larger. Therefore, by increasing the contact area between the retainer 4 and the outer ring 2, the durability of the retainer 4 can be effectively improved.

[0106] In addition, if Figure 8 , Fig. 9 As shown, the ball bearing is provided with R chamfered portions 20 with a circular arc shape in cross section smoothly connected to the second outer ring guide surface 18 at both ends of the second outer ring guide surface 18 in the circumferential direction of the outer ring guide protrusion 15, so that Figure 4 , Figure 5As shown, when the retainer 4 moves in the eccentric direction due to the centrifugal force accompanying the eccentric rotation and the second outer ring guide surface 18 of the outer circumference of the outer ring guide projection 15 comes into sliding contact with the outer ring groove shoulder 10, the lubricant on the inner circumference of the outer ring groove shoulder 10 is not easily scraped off by the circumferential edge of the second outer ring guide surface 18. Therefore, the lubricity between the second outer ring guide surface 18 of the outer circumference of the outer ring guide projection 15 and the inner circumference of the outer ring groove shoulder 10 can be well maintained. The same effect can be obtained by providing C chamfered portions intersecting the second outer ring guide surface 18 at obtuse angles at both ends of the circumferential direction of the second outer ring guide surface 18 of the outer circumference of the outer ring guide projection 15 instead of the R chamfered portions 20.

[0107] In addition, if Figure 5 As shown, the inner surface of the pocket 13 of the ball bearing is formed into a cylindrical shape extending in the radial direction, so when the retainer 4 moves in the eccentric direction due to the centrifugal force accompanying the eccentric rotation, the inner surface of the pocket 13 of the retainer 4 can be reliably prevented from interfering with the ball 3.

[0108] In addition, if Figure 8 As shown, the distance a between the front ends of the outer ring guide protrusions 15 of the ball bearing is set to be equal to or larger than the inner diameter b of the inner surface of the pocket 13, so that when the ball 3 is inserted into the pocket 13, it is possible to reliably prevent the ball 3 from interfering with the outer ring guide protrusion 15. In addition, when the retainer 4 is resin-molded, it is possible to avoid forced extraction from the mold.

[0109] In addition, the retainer 4 of the ball bearing is formed of a resin composition, so it has self-lubricating properties even when used under dilute lubrication conditions. In addition, the retainer 4 is formed of a resin composition, so it is also excellent in quietness when used for eccentric rotation purposes, and has low noise.

[0110] Figure 10 to Figure 12 The second embodiment of the present invention is shown. The second embodiment differs from the first embodiment only in the shape of the pocket 13 of the retainer 4, and the other structures are basically the same as the first embodiment. Therefore, the same reference numerals are given to the same parts as the first embodiment, and the description thereof is omitted.

[0111] The surface of the column base 14 facing the ball 3 and the surface of the ball retaining claw 16 facing the ball 3 form the inner surface of the pocket 13 for accommodating the ball 3. The inner surface of the pocket 13 is a spherical surface along the surface of the ball 3. Fig.11 As shown, the side surfaces 19 on both axial sides of the outer ring guide protrusion 15 are formed into cylindrical surfaces (cylindrical surfaces extending parallel to the axial direction) connected to the spherical inner surface of the pocket 13. The ball bearing of this embodiment can also be mounted on the same as the first embodiment. Fig.13 , Fig.14 The outer periphery of the eccentric shaft portion 32 of the eccentric rotating device shown is used.

[0112] The ball bearing of this embodiment also adopts the outer ring guide method as the guide method of the retainer 4, similarly to the first embodiment. Therefore, when the centrifugal force accompanying the eccentric rotation is generated in the retainer 4 and the balls 3, it is possible to prevent the retainer 4 from contacting only a part of the balls 3 with a high surface pressure. In addition, an outer ring guide surface 17 is provided on the outer periphery of the annular portion 11 of the retainer 4 to slide against the outer ring groove shoulder portion 9 on one side, and a guide surface 17 is provided on each column portion 12 to slide against the outer ring groove shoulder portion 10 on the other side (see Figure 4 ) The outer ring guide protrusion 15 in sliding contact with the outer ring guide protrusion 15 is formed. Therefore, when the centrifugal force generated in the crown-shaped resin retainer 4 and the ball 3 accompanying the eccentric rotation causes the retainer 4 to move radially in the eccentric direction, the retainer 4 is supported by the pair of outer ring groove shoulders 9 and 10 on both axial sides of the outer ring raceway groove 8. Therefore, when the centrifugal force generated in the retainer 4 and the ball 3 accompanying the eccentric rotation is generated, the retainer 4 is not easy to tilt, and the outer periphery of the column portion 12 located in the eccentric direction can be prevented from colliding with the intersecting edge of the outer ring groove shoulder 9 and the outer ring raceway groove 8. Other effects are also the same as those of the first embodiment.

[0113] In the above embodiment, a hollow annular component having an inner ring raceway groove 5 formed on the outer circumference is used as an example for the inner ring 1, but the inner ring 1 is not necessarily a hollow annular component, and a solid component (shaft body) having an inner ring raceway groove 5 directly formed on the outer circumference for rolling contact of the balls 3 may be used as the inner ring 1. In short, the inner ring (innerrace) can be any inner component having an annular inner ring raceway groove 5 on the outer circumference for rolling contact of the balls 3.

[0114] In addition, in the above-mentioned embodiments, a hollow annular component having an outer ring raceway groove 8 formed on the inner circumference is used as an example for explanation as the outer ring 2, but the outer ring 2 is not necessarily a hollow annular component, and as the outer ring 2, for example, a bearing box having an outer ring raceway groove 8 directly formed on the inner circumference for rolling contact with the balls 3 may be used. In short, the outer ring (outer race) may be any outer component having an annular outer ring raceway groove 8 on the inner circumference for rolling contact with the balls 3.

[0115] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0116] Description of Reference Numerals

[0117] 1…Inner ring; 2…Outer ring; 3…Ball; 4…Crown-shaped resin retainer; 8…Outer ring raceway groove; 9, 10…Outer ring groove shoulder; 11…Annular portion; 12…Column portion; 13…Pocket; 15…Outer ring guide protrusion; 16…Ball retaining claw; 17…Outer ring guide surface; 18…Second outer ring guide surface; 20…R chamfered portion; 21…Separation groove; 22…Arc edge portion; 30…Rotation axis; 32…Eccentric shaft portion; a…The distance between the front ends of the outer ring guide protrusions; b…The inner diameter of the inner surface of the pocket (the arc diameter of the arc edge portion); c…The distance between the front ends of the ball retaining claws; C0…The rotation center of the rotation axis; C1…The center of the outer circumference of the eccentric shaft portion.

Claims

1. A ball bearing with an outer ring guide retainer, comprising: Inner circle (1); An outer ring (2) coaxially arranged radially outside the inner ring (1); a plurality of balls (3) assembled between the inner ring (1) and the outer ring (2); and a crown-shaped resin retainer (4) which retains the plurality of balls (3), An outer ring raceway groove (8) for rolling contact of the ball (3) and a pair of outer ring groove shoulders (9, 10) located on both axial sides of the outer ring raceway groove (8) are provided on the inner periphery of the outer ring (2). The crown-shaped resin retainer (4) comprises an annular portion (11) disposed opposite to the radial inner side of the outer ring groove shoulder portion (9) of one of the pair of outer ring groove shoulder portions (9, 10), and a plurality of cantilever beam-shaped column portions (12) extending axially from the annular portion (11) at intervals in the circumferential direction. An outer ring guide surface (17) is provided on the outer periphery of the annular portion (11) and is in sliding contact with the outer ring groove shoulder portion (9). The ball bearing with outer ring guide retainer is characterized in that: Each column portion (12) has an outer ring guide protrusion (15) that is in sliding contact with the other outer ring groove shoulder portion (10) of the pair of outer ring groove shoulder portions (9, 10).

2. The ball bearing with outer ring guide retainer according to claim 1, characterized in that: Each of the column portions (12) further comprises a pair of ball retaining claws (16) extending axially at intervals in the circumferential direction, and a separation groove (21) separating the pair of ball retaining claws (16) from the outer ring guide protrusion (15) in a manner that the pair of ball retaining claws (16) can be deformed circumferentially independently from the outer ring guide protrusion (15).

3. The ball bearing with outer ring guide retainer according to claim 2, characterized in that: The pair of ball retaining claws (16) are arranged to face each other on the radial inner side of the outer ring guide protrusion (15). The separation groove (21) is formed to extend in the circumferential direction between the pair of ball retaining claws (16) and the outer ring guide protrusion (15) so as to separate the pair of ball retaining claws (16) from the outer ring guide protrusion (15) in the radial direction.

4. The ball bearing with an outer ring guide retainer according to any one of claims 1 to 3, characterized in that: A second outer ring guide surface (18) is provided on the outer periphery of the outer ring guide protrusion (15) and is in sliding contact with the other outer ring groove shoulder portion (10). An R chamfered portion (20) with an arc-shaped cross section smoothly connected to the second outer ring guide surface (18) or a C chamfered portion intersecting the second outer ring guide surface (18) at an obtuse angle is provided at both ends of the second outer ring guide surface (18) in the circumferential direction.

5. The ball bearing with an outer ring guide retainer according to any one of claims 1 to 4, characterized in that: Pockets (13) for accommodating the plurality of balls (3) are formed between the column portions (12) adjacent to each other in the circumferential direction. The inner surface of the pocket (13) is formed into a cylindrical shape extending in the radial direction.

6. The ball bearing with outer ring guide retainer according to claim 5, characterized in that: The distance (a) between the front ends of the outer ring guide protrusions (15) located on both sides of the ball (3) in the circumferential direction is set to be the same as or larger than the inner diameter of the inner surface of the pocket (13).

7. A ball bearing with an outer ring guide retainer according to any one of claims 1 to 4, characterized in that: Pockets (13) for accommodating the plurality of balls (3) are formed between the column portions (12) adjacent to each other in the circumferential direction. The inner surface of the pocket (13) is formed into a spherical shape along the surface of the ball (3). The opening of the pocket (13) toward the outer periphery of the crown-shaped resin retainer (4) has a semicircular arc edge (22) open in the axial direction. The distance (a) between the front ends of the outer ring guide protrusions (15) located on both sides of the ball (3) in the circumferential direction is set to be the same as or larger than the arc diameter (b) of the arc edge (22).

8. The ball bearing with an outer ring guide retainer according to claim 2 or 3, characterized in that: The distance (c) between the front ends of the ball retaining claws (16) which are circumferentially opposed to each other with the ball (3) interposed therebetween is set to be not less than 80% and not more than 92% of the diameter of the ball (3).

9. An eccentric rotating device, characterized in that: have: A rotating shaft (30), wherein the rotating shaft (30) rotates at a fixed position; an eccentric shaft portion (32) having a cylindrical outer periphery with a position eccentric from a rotation center (C0) of the rotation shaft (30) as a center (C1), and eccentrically rotating around the rotation center (C0) of the rotation shaft (30); and A ball bearing with an outer ring guide retainer according to any one of claims 1 to 8, wherein the ball bearing with an outer ring guide retainer is mounted on the outer periphery of the eccentric shaft portion (32).

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