JP2005214330A - Four-point contact ball bearing and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce frictional torque, prevent abrasion and improve the life by improving the surface roughness of rolling surfaces of inner and outer rings, and to prevent temperature rise and generation of abnormal sound of a bearing by restraining the rolling surface from being out of shape. <P>SOLUTION: This four-point contact ball bearing 1 includes: an outer ring 2 provided with an outer rolling surface 2a formed on the inner periphery; an inner ring 3 provided with an inner rolling surface 3a formed opposite to the outer rolling surface 2a on the outer periphery; and a plurality of balls 5 stored to freely roll between the outer rolling surface 2a and the inner rolling surface 3a. The respective rolling surfaces 2a, 3a are formed Gothic arch-like in section to come into contact with the ball 5 in two points. The outer ring 2 and the inner ring 3 are formed of two ring members 6, 7, 8, 9 abutted on each other, and the respective rolling surfaces 2a, 3a are provided with a superfinishing surface having a predetermined surface roughness. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a ball bearing that rotatably supports an assist motor shaft of an electric power steering, and more particularly, a ball bearing that is held so that the balls contact each other between the inner ring and the outer ring, and the balls contact the inner ring and the outer ring at two points. The present invention relates to a four-point contact ball bearing having a running surface and a manufacturing method thereof.

  Generally, in rolling bearings, it is necessary to secure a lubricating oil film having a sufficient thickness compared to the surface roughness on the contact surface between the inner ring and outer ring and the rolling elements in order to reduce friction torque, prevent wear, and improve the service life. . Therefore, in a general rolling bearing such as a deep groove ball bearing, after the rolling surface is formed into a predetermined shape by grinding, super finishing is further performed to reduce the surface roughness.

  Among ball bearings, there are multi-point contact ball bearings such as a three-point contact ball bearing and a four-point contact ball bearing. In such a multi-point contact ball bearing, a rolling contact surface that contacts the ball at two points is formed on at least one of the inner ring and the outer ring. As the cross-sectional shape of the rolling contact surface that makes contact with the ball at two points, a Gothic arch, an ellipse, a V-shape or the like is appropriately employed depending on the application and use conditions. In particular, four-point contact ball bearings are single-row bearings and can carry radial loads and bidirectional thrust loads. Is widely used in applications where high-speed rotation is used, and where double-row angular ball bearings such as double-row angular ball bearings cannot be used due to lack of space. Further, this four-point contact ball bearing has the convenience that the range of the axial clearance relative to the radial clearance can be suppressed, so that the backlash of the device after assembly can be suppressed.

  A typical example of such a four-point contact ball bearing is shown in FIG. The four-point contact ball bearing 50 includes an inner ring 51, an outer ring 52, and a plurality of balls 53 that are rotatably held by a cage 54 between the inner and outer rings 51, 52. The inner ring 51 is composed of a pair of ring members 55 and 56 that are joined together. Each of the ring members 55 and 56 is formed with rolling surfaces 55a and 56a having an arcuate cross-sectional shape with a predetermined radius of curvature, and the rolling surfaces 55a and 56a cooperate with each other to form a cross-sectional shape of the Gothic arch. The rolling surface 51a which has is formed.

  On the other hand, the outer ring 52 is composed of one ring member, and a rolling surface 52a having a Gothic arch cross-sectional shape is formed on the ring member. The surface roughness of the rolling surface 52a is adjusted by barrel processing. Each ball 53 is held between the inner ring 51 and the outer ring 52 so as to be in contact with the rolling surface 51a of the inner ring 51 at two points and in contact with the rolling surface 52a of the outer ring 52 at two points. ing.

Thus, when the rolling surface 52a having a cross-sectional shape made of a Gothic arch is formed in the outer ring 52 constituted by one ring member, superfinishing is performed on the rolling surface 52a of the outer ring 52. Although it is difficult to carry out efficiently, the surface roughness of the rolling surface 52a of the outer ring 52 can be improved by barrel processing, and the friction torque of the four-point contact ball bearing 50 is reduced, wear is prevented, and durability is improved. Can do.
Japanese Patent Laid-Open No. 11-62990

  However, in the conventional four-point contact ball bearing 50, the outer ring 52 formed of one ring member is formed into a predetermined shape by grinding the gothic arch-shaped rolling surface 52a, and then barrel processing is performed. Although it is possible to improve the surface roughness of the rolling surface 52a, the processing time becomes long, and it is not easy to stably secure the bus bar shape and the surface roughness of the rolling surface 52a.

  The present invention has been made in view of such a conventional problem, and improves the surface roughness of the rolling surface of the inner and outer rings, reduces friction torque, prevents wear and improves the life, and forms the rolling surface. An object of the present invention is to provide a four-point contact ball bearing that suppresses collapse and prevents the bearing from rising in temperature and generating abnormal noise.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer ring having an outer rolling surface formed on the inner periphery and an inner rolling surface facing the outer rolling surface on the outer periphery. And a plurality of balls accommodated in a freely rolling manner between the outer raceway surface and the inner raceway surface, and each of the raceway surfaces has a cross-sectional shape in contact with the ball at two points. In the formed four-point contact ball bearing, the outer ring and the inner ring are constituted by a pair of ring members that are abutted with each other, and super-finished surfaces having a predetermined surface roughness are formed on the respective rolling surfaces. Adopted the configuration.

  In this way, the outer ring and the inner ring are configured by a pair of ring members that are abutted with each other, and the superfinished surface having a predetermined surface roughness is formed on each rolling surface, so that a predetermined bus bar is formed. The shape can be obtained and the surface roughness can be reduced. Therefore, it is possible to provide a four-point contact ball bearing that can reduce friction torque, prevent wear, improve the life, and prevent the bearing from being heated and generating abnormal noise.

  Further, in the invention according to claim 2, since the pair of ring members constituting the outer ring and the inner ring are integrated by the connecting means, the handling of the bearing is simplified, and at the time of assembling the bearing in an apparatus or the like. This misalignment can be suppressed.

  Further, as the connecting means, as in the invention according to claim 3, through holes extending in the axial direction are formed in the outer ring and the inner ring, respectively, and fixing bolts are fitted into the through holes, and the pair of nuts are inserted with nuts. These ring members may be integrally fastened. Further, as in a fourth aspect of the invention, a plurality of circular grooves are formed on the outer peripheral surface of the outer ring and the inner peripheral surface of the inner ring so as to straddle the butting surfaces of the pair of ring members. A retaining ring may be fitted to the base. Further, as in the invention according to claim 5, a pair of annular grooves are formed on the outer peripheral surface of the outer ring and the inner peripheral surface of the inner ring with the butting surfaces of the pair of ring members interposed therebetween, and these annular grooves A connecting ring having a substantially U-shaped cross section may be fitted to the.

  Preferably, as in the invention described in claim 6, if the rolling surfaces of the outer ring and the inner ring are formed in the cross-sectional shape of the Gothic arch, the range of the axial clearance with respect to the radial clearance of the bearing is set. Since it can suppress, the backlash of the apparatus after an assembly can be suppressed.

  According to a seventh aspect of the present invention, there is provided a method invention according to claim 7, wherein an outer ring having an outer rolling surface formed on the inner periphery, and an inner ring having an inner rolling surface opposed to the outer rolling surface formed on the outer periphery. And a plurality of balls accommodated in a freely rolling manner between the outer rolling surface and the inner rolling surface, and each rolling surface is formed in a cross-sectional shape in contact with the ball at two points. In the method of manufacturing a point contact ball bearing, after a pair of ring members constituting the outer ring and the inner ring are connected to each other in a state of being abutted with each other and formed into a predetermined arc-shaped cross-sectional shape by grinding, super finishing Or the pair of ring members are separated, the pair of ring members are individually superfinished, and then the respective butted surfaces of the ring members are cut by a predetermined amount by grinding, Again, the pair of ring members The butt.

  By adopting such a manufacturing method, it is possible to efficiently reduce the surface roughness of each rolling surface without breaking the predetermined bus bar shape formed by grinding.

  In the invention according to claim 8, an annular groove having a V-shaped cross section is formed in advance in the center of the width of the outer peripheral surface of the outer ring material and the inner peripheral surface of the inner ring material, each of which is composed of one ring member. Then, after forming a predetermined arc-shaped cross-sectional shape by grinding, super-finishing is performed, and then a wedge jig is put in the annular groove to separate each of the pair of ring members. Since the butt surface is cut by a predetermined amount by grinding, at least the number of processing steps in the previous process can be reduced, the process of connecting a pair of ring members can be omitted, and position shift at that time can be prevented Therefore, the dimensional accuracy can be further improved.

  In addition, the method invention according to claim 9 of the present invention includes an outer ring having an outer rolling surface formed on the inner periphery, and an inner ring having an inner rolling surface opposed to the outer rolling surface on the outer periphery. And a plurality of balls accommodated in a freely rolling manner between the outer rolling surface and the inner rolling surface, and each rolling surface is formed in a cross-sectional shape in contact with the ball at two points. In the method of manufacturing a point contact ball bearing, a pair of ring members constituting the outer ring and the inner ring are connected in a state of being abutted with each other in advance through a spacer having a predetermined thickness, and a predetermined arc shape is obtained by grinding. After being formed into a cross-sectional shape, superfinishing was performed, and then the spacer was removed to form a rolling surface having a predetermined cross-sectional shape.

  By adopting such a manufacturing method, it is only necessary to grind a pair of ring members to a predetermined width dimension in the previous process as in the prior art, and the butt surfaces of the pair of ring members are superfinished of rolling surfaces. Grinding may not be performed after the processing, and it is possible to prevent the rolling surface from being damaged in the width grinding process.

  The four-point contact ball bearing according to the present invention includes an outer ring having an outer rolling surface formed on the inner periphery, an inner ring having an inner rolling surface facing the outer rolling surface on the outer periphery, and the outer rolling In a four-point contact ball bearing comprising a plurality of balls accommodated in a freely rollable manner between a surface and an inner rolling surface, wherein each rolling surface is formed in a cross-sectional shape in contact with the ball at two points. The outer ring and the inner ring are composed of a pair of ring members that are faced to each other, and a predetermined superfinished surface is formed on each rolling surface, so that a predetermined bus bar shape can be obtained, and The surface roughness can be reduced. Therefore, it is possible to provide a four-point contact ball bearing that can reduce friction torque, prevent wear, improve the life, and prevent the bearing from being heated and generating abnormal noise.

  Moreover, the manufacturing method of the four-point contact ball bearing according to the present invention includes an outer ring in which an outer rolling surface is formed on the inner periphery, and an inner ring in which an inner rolling surface facing the outer rolling surface is formed on the outer periphery. And a plurality of balls accommodated in a freely rolling manner between the outer rolling surface and the inner rolling surface, and each rolling surface is formed in a cross-sectional shape in contact with the ball at two points. In the method for manufacturing a point contact ball bearing, a pair of ring members constituting the outer ring and the inner ring are connected in a state of being abutted with each other and formed into a predetermined arcuate cross-sectional shape by grinding, and then superfinishing is performed. Or the pair of ring members are separated, the pair of ring members are individually subjected to post-superfinishing, and then the respective butted surfaces of the ring members are cut by a predetermined amount by grinding, Shaped on rolling surface with predetermined cross-sectional shape Since the, without disturbing a predetermined generatrix shape formed by grinding, can be a surface roughness of the rolling surfaces efficiently reduced. In addition, it is not necessary to make a significant process change by simply modifying a part of the conventional manufacturing process, and a desired four-point contact ball bearing can be manufactured online as in the prior art.

  Moreover, the manufacturing method of the four-point contact ball bearing according to the present invention includes an outer ring in which an outer rolling surface is formed on the inner periphery, and an inner ring in which an inner rolling surface facing the outer rolling surface is formed on the outer periphery. And a plurality of balls accommodated in a freely rolling manner between the outer rolling surface and the inner rolling surface, and each rolling surface is formed in a cross-sectional shape in contact with the ball at two points. In the method of manufacturing a point contact ball bearing, a pair of ring members constituting the outer ring and the inner ring are connected in a state of being abutted with each other in advance through a spacer having a predetermined thickness, and a predetermined arc shape is obtained by grinding. Since the superfinishing is performed after the cross-sectional shape is formed, and then the spacer is removed and formed on the rolling surface having a predetermined cross-sectional shape, the pair of ring members is formed in the previous step as in the prior art. Just grinding to the specified width May, may not be grinding the abutment surfaces of the pair of ring members after superfinished the rolling surface, can bruise like the rolling run face width grinding step can be prevented.

  An outer ring having an outer rolling surface formed on the inner periphery, an inner ring having an inner rolling surface facing the outer rolling surface on the outer periphery, and rolling freely between the outer rolling surface and the inner rolling surface. A four-point contact ball bearing in which each rolling surface is formed in a cross-sectional shape of a Gothic arch that contacts the ball at two points. Each of the rolling surfaces is formed with a superfinished surface having a predetermined surface roughness.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of a four-point contact ball bearing according to the present invention.
The four-point contact ball bearing 1 is accommodated between an outer ring 2 having an outer rolling surface 2a formed on the inner periphery, an inner ring 3 having an inner rolling surface 3a formed on the outer periphery, and both rolling surfaces 2a and 3a. The ball 5 is held by the cage 4 so as to be freely rollable.

  The outer ring 2 is composed of a pair of outer ring members 6 and 7 that face each other. Rolling surfaces 6a and 7a each having an arcuate cross-sectional shape having a predetermined radius of curvature are formed on the inner circumferences of the outer ring members 6 and 7, respectively. The rolling surfaces 6a and 7a cooperate with each other to form Gothic. A cross-sectional shape of the arch, that is, a rolling surface 3a having a circular arc surface having a pair of centers of curvature offset by an equal distance in the axial direction with respect to the width center of the bearing is formed. On the other hand, the inner ring 3 is also composed of a pair of inner ring members 8 and 9 that are abutted with each other, and the inner ring member 8 and 9 has an arcuate cross-sectional shape having a predetermined radius of curvature on the outer periphery thereof. Each rolling surface 8a, 9a is formed, and each rolling surface 8a, 9a cooperates with each other to form a rolling surface 3a having a Gothic arch cross-sectional shape.

  The outer ring 2 and the inner ring 3 are respectively provided with through holes 10 and 10 extending in the axial direction. Fixing bolts 11 and 11 are fitted into the through holes 10 and 10, and the outer ring members 6 and 7 are fitted with nuts 12 and 12. The inner ring members 8 and 9 are fastened together. Thereby, since the pair of outer ring members 6 and 7 constituting the outer ring 2 and the pair of inner ring members 8 and 9 constituting the inner ring 3 are integrated by the connecting means, the handling of the bearing becomes simple, Misalignment when assembling a bearing in a device or the like can be suppressed.

  The pair of outer ring members 6 and 7 constituting the outer ring 2 are superfinished after forming the inner peripheral surface into a predetermined arc-shaped cross-sectional shape by grinding in a state in which the outer ring members 6 and 7 are abutted with each other in advance by a connecting jig or the like. Process to reduce surface roughness. Then, it isolate | separates into a pair of outer ring members 6 and 7, and each abutment surface 6b of each outer ring member 6 and 7 is cut by predetermined amount by grinding. After this width grinding, the pair of outer ring members 6 and 7 are integrally combined again to form an outer rolling surface 2a having a Gothic arch cross-sectional shape, that is, an outer rolling surface 2a that is in contact with the ball 5 at two points. Will be formed.

  On the other hand, the inner ring 3 also has a pair of inner ring members 8 and 9 which are formed in a predetermined arcuate cross-sectional shape by grinding the outer peripheral surface in a state in which the pair of inner ring members 8 and 9 are abutted with each other in advance. Finish the surface to reduce the surface roughness. Then, it separates into a pair of inner ring members 8 and 9, and each abutting face 8b and 9b of each inner ring member 8 and 9 is cut by predetermined amount by grinding. After this width grinding, the pair of inner ring members 8 and 9 are integrally combined again, and the inner rolling surface 3a having a Gothic arch cross-sectional shape, that is, the inner rolling surface 3a in contact with the ball 5 at two points is formed. Will be formed.

  Accordingly, the same level as that of a general ball bearing such as a deep groove ball bearing, that is, the surface roughness of the rolling surface is 0.2 to 0.4 Ra after grinding, and is 0. 0 after superfinishing. It becomes possible to regulate to the range of 05-0.1Ra. Therefore, the surface roughness of each rolling surface 2a, 3a can be efficiently reduced without destroying the predetermined bus bar shape formed by grinding, while reducing friction torque and preventing wear and improving the life, It is possible to provide a four-point contact ball bearing that prevents the temperature rise of the bearing and the generation of abnormal noise. In addition, it is not necessary to make a significant process change by simply modifying a part of the conventional manufacturing process, and a desired four-point contact ball bearing can be manufactured online as in the prior art. In addition, although what made each rolling surface 2a, 3a the cross-sectional shape of the Gothic arch was illustrated here, of course, not only this but an elliptical or V-shaped cross-sectional shape may be sufficient, for example.

  In addition to this, for example, in the case of the outer ring 2, the inner peripheral surface is ground in a state where the pair of outer ring members 6 and 7 constituting the outer ring 2 are abutted in advance with a connecting jig or the like. Are formed into a predetermined arcuate cross-sectional shape, separated into a pair of outer ring members 6, 7, and after the pair of outer ring members 6, 7 are separately superfinished, each outer ring member 6 , 7 may be cut by a predetermined amount by grinding.

  In addition, a spacer having a predetermined thickness is interposed between the butting surfaces 6b and 7b of the pair of outer ring members 6 and 7, and the inner circumferential surface is integrated with a connecting jig or the like so that the inner peripheral surface is predetermined by grinding. An arcuate cross-sectional shape may be formed, and the pair of outer ring members 6 and 7 may be superfinished integrally, and then the spacer may be removed. In such a manufacturing method, it is only necessary to grind a pair of ring members to a predetermined width dimension in the previous process as in the prior art, and it is not necessary to grind the butted surfaces of the pair of ring members after superfinishing the rolling surfaces. Also good. Therefore, it is possible to prevent the rolling surface from being scratched or the like in the width grinding process without strict handling.

  Furthermore, as another superfinishing process, for example, in the case of the outer ring 2, an annular groove having a V-shaped cross section is formed in advance on the outer peripheral surface (width central portion) of the outer ring material made of one ring member, and the inner peripheral surface is ground. After forming a predetermined arc-shaped cross-sectional shape with, and further superfinishing, insert a wedge jig into the annular groove to separate it into a pair of ring members, and grind the butted surfaces of these pair of ring members A predetermined amount may be cut at. By this method, at least the processing man-hours of the previous process can be reduced, the process of connecting the pair of ring members can be omitted, and displacement at that time can be prevented, thereby further improving the dimensional accuracy. Can do.

  FIG. 2 is a longitudinal sectional view showing a second embodiment of the four-point contact ball bearing according to the present invention, and FIG. 3 is a fragmentary view of the main part of FIG. This second embodiment differs from the first embodiment described above only in the means for fixing the pair of ring members, and the same parts and parts as those in the first embodiment are denoted by the same reference numerals and details thereof are described. The detailed explanation is omitted.

  This four-point contact ball bearing 12 is accommodated between an outer ring 13 having an outer rolling surface 2a formed on the inner periphery, an inner ring 14 having an inner rolling surface 3a formed on the outer periphery, and both rolling surfaces 2a, 3a. The ball 5 is held by the cage 4 so as to be freely rollable.

  The outer ring 13 includes a pair of outer ring members 15 and 16 that are abutted with each other. Rolling surfaces 6a and 7a each having an arcuate cross-sectional shape having a predetermined radius of curvature are formed on the inner circumferences of the outer ring members 15 and 16, respectively. The rolling surfaces 6a and 7a cooperate with each other to form Gothic. A rolling surface 2a having an arch cross-sectional shape is formed. On the other hand, like the outer ring 13, the inner ring 14 is also composed of a pair of inner ring members 17 and 18 that are abutted with each other, and the inner ring members 17 and 18 have an arcuate cross-sectional shape having a predetermined radius of curvature on the outer periphery. Each rolling surface 8a, 9a is formed, and each rolling surface 8a, 9a cooperates with each other to form a rolling surface 3a having a Gothic arch cross-sectional shape.

  In the present embodiment, a plurality of circular grooves 19 are formed on the outer peripheral surface of the outer ring 13 so as to straddle the butted surfaces 6b and 7b. Further, the circular groove 19 is formed so that the cross section has a dovetail shape and the opening is narrower than the bottom. A metal retaining ring 20 is fitted in the circular groove 19. The retaining ring 20 is set to have a slightly larger wire diameter than the opening of the circular groove 19 and is press-fitted with a squeeze. Thereby, since the retaining ring 20 is fitted in a slightly plastically deformed state, the pair of outer ring members 15 and 16 are firmly integrated without play. On the other hand, the inner ring 14 is also formed with a plurality of circular grooves 21 on the inner peripheral surface so as to straddle the butted surfaces 8b and 9b. The retaining ring 20 is fitted into the circular groove 21, and the pair of inner ring members 17 and 18 are firmly integrated without play.

  FIG. 4 is a longitudinal sectional view showing a third embodiment of the four-point contact ball bearing according to the present invention. The third embodiment is different from the above-described embodiment only in the means for fixing the pair of ring members, and the same parts are denoted by the same reference numerals and detailed description thereof is omitted.

  This four-point contact ball bearing 22 is accommodated between an outer ring 23 having an outer rolling surface 2a formed on the inner periphery, an inner ring 24 having an inner rolling surface 3a formed on the outer periphery, and both rolling surfaces 2a, 3a. The ball 5 is held by the cage 4 so as to be freely rollable.

  The outer ring 23 is composed of a pair of outer ring members 25 and 26 that are butted against each other. Rolling surfaces 6a and 7a each having an arcuate cross-sectional shape having a predetermined radius of curvature are formed on the inner circumferences of the outer ring members 25 and 26, and the rolling surfaces 6a and 7a cooperate with each other to form Gothic. A rolling surface 2a having an arch cross-sectional shape is formed. On the other hand, like the outer ring 23, the inner ring 24 is also composed of a pair of inner ring members 27 and 28 which are abutted with each other, and the inner ring members 27 and 28 have an arcuate cross-sectional shape having a predetermined radius of curvature on the outer periphery. Each rolling surface 8a, 9a is formed, and each rolling surface 8a, 9a cooperates with each other to form a rolling surface 3a having a Gothic arch cross-sectional shape.

  In the present embodiment, a pair of annular grooves 29 and 29 are formed on the outer peripheral surface of the outer ring 23 with the butting surfaces 6b and 7b interposed therebetween. A connecting ring 30 having a substantially U-shaped cross section is fitted in the annular grooves 29 and 29. By elastically deforming the connecting ring 30 and mounting it in the annular groove 29, the pair of outer ring members 25 and 26 are firmly integrated without play. On the other hand, the inner ring 24 also has a pair of annular grooves 31 formed on the inner peripheral surface with the butted surfaces 8b and 9b interposed therebetween. A connecting ring 32 is attached to the annular groove 31, and the pair of inner ring members 27 and 28 are firmly integrated without play. In this example, the connection rings 30 and 32 made of steel plate and having the surface hardened are elastically deformed and attached to the annular grooves 29 and 31. However, the present invention is not limited to this example. The ring-shaped groove may be plastically deformed and caulked and attached, and the pair of ring members may be firmly integrated without play.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The four-point contact ball bearing according to the present invention is a four-point contact ball bearing that is used in an environment where thrust space in both the left and right directions is applied, the bearing space is restricted, and quietness is required at high speed rotation. Applicable to.

It is a longitudinal section showing a 1st embodiment of a four-point contact ball bearing concerning the present invention. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the four-point contact ball bearing which concerns on this invention. It is the principal part arrow line view which looked at FIG. 2 from upper direction. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the four-point contact ball bearing which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional four-point contact ball bearing.

Explanation of symbols

1, 12, 22 ... Four-point contact ball bearings 2, 13, 23 ... Outer ring 2a ... ..Outer rolling surface 3, 14, 24 ... Inner ring 3a ... Inner rolling surface 4 ... ······································ Balls 6, 7, 15, 16, 25, 26 ··· Outer ring members 6a, 7a, 8a , 9a... Rolling surfaces 6b, 7b, 8b, 9b... Butting surfaces 8, 9, 17, 18, 27, 28 .. Inner ring member 10. ... through hole 11 ... fixing bolt 12 ... nuts 19, 21 ... ............ Circular groove 20 ............ Stop Rings 29, 31 ..... Annular grooves 30, 32 ..... Connection ring 50 .....・ Four-point contact ball bearings 51 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rings 51a, 52a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling surface 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... outer ring 53 ... ball 54 ... cage 55, 56 ...・ ・ ・ ・ ・ ・ Ring members 55a and 56a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling surface

Claims (9)

An outer ring having an outer rolling surface formed on the inner periphery, an inner ring having an inner rolling surface facing the outer rolling surface on the outer periphery, and rolling freely between the outer rolling surface and the inner rolling surface. A four-point contact ball bearing formed in a cross-sectional shape in which each rolling surface is in contact with the ball at two points, respectively.
The four-point contact characterized in that the outer ring and the inner ring are composed of a pair of ring members that are abutted with each other, and a superfinished surface having a predetermined surface roughness is formed on each rolling surface. Ball bearing.   The four-point contact ball bearing according to claim 1, wherein a pair of ring members constituting the outer ring and the inner ring are integrated by a connecting means.   The four points according to claim 2, wherein a through hole extending in the axial direction is formed in each of the outer ring and the inner ring, a fixing bolt is fitted into the through hole, and the pair of ring members are fastened together with a nut. Contact ball bearing.   A plurality of circular grooves are formed on the outer peripheral surface of the outer ring and the inner peripheral surface of the inner ring so as to straddle the butting surfaces of the pair of ring members, and a retaining ring is fitted to these circular grooves. The four-point contact ball bearing described.   A pair of annular grooves are formed on the outer peripheral surface of the outer ring and the inner peripheral surface of the inner ring with the butting surfaces of the pair of ring members interposed therebetween, and a connecting ring having a substantially U-shaped cross section is fitted into these annular grooves. The four-point contact ball bearing according to claim 2.   The four-point contact ball bearing according to any one of claims 1 to 5, wherein rolling surfaces of the outer ring and the inner ring are formed in a cross-sectional shape of a Gothic arch. An outer ring having an outer rolling surface formed on the inner periphery, an inner ring having an inner rolling surface facing the outer rolling surface on the outer periphery, and rolling freely between the outer rolling surface and the inner rolling surface. A plurality of balls accommodated in a four-point contact ball bearing formed in a cross-sectional shape in which each rolling surface is in contact with the ball at two points,
A pair of ring members constituting the outer ring and the inner ring are connected in a state of being butted against each other and formed into a predetermined arcuate cross-sectional shape by grinding, and then superfinishing is performed, or the pair of rings The ring members are separated, and the pair of ring members are individually superfinished, and then the respective butting surfaces of the ring members are cut by a predetermined amount by grinding, and again the pair of ring members are A method of manufacturing a four-point contact ball bearing, characterized in that they are matched.   An annular groove having a V-shaped cross section is formed in advance in the center of the width of the outer peripheral surface of the outer ring material and the inner peripheral surface of the inner ring material, each of which is composed of one ring member, and a predetermined arc-shaped cross section is obtained by grinding. After forming into a shape, superfinishing is performed, and then a wedge jig is inserted into the annular groove to separate each of the pair of ring members, and the butted surfaces of the pair of ring members are cut by a predetermined amount by grinding. The manufacturing method of the four-point contact ball bearing of Claim 7 which was made to do. An outer ring having an outer rolling surface formed on the inner periphery, an inner ring having an inner rolling surface facing the outer rolling surface on the outer periphery, and rolling freely between the outer rolling surface and the inner rolling surface. A plurality of balls accommodated in a four-point contact ball bearing formed in a cross-sectional shape in which each rolling surface is in contact with the ball at two points,
A pair of ring members constituting the outer ring and the inner ring are connected in a state of being abutted with each other in advance through a spacer having a predetermined thickness, and formed into a predetermined arc-shaped cross-sectional shape by grinding, and then superfinishing A method of manufacturing a four-point contact ball bearing, characterized in that a processing is performed and then the spacer is removed to form a rolling surface having a predetermined cross-sectional shape.

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