JP2008138842A - Tandem type double row angular contact ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tandem type double row angular contact ball bearing capable of preventing running-on to the shoulder of a ball (a rolling body), by enhancing axial rigidity. <P>SOLUTION: This tandem type double row angular contact ball bearing has an inner race 12 having raceway surfaces 11a and 11b of double rows, an outer race 14 having raceway surfaces 13a and 13b of double rows corresponding to the raceway surfaces 11a and 11b of the inner race 12, and ball groups 15 and 16 of double rows interposed with respectively different pitch circle diameters between the raceway surfaces 11a, 11b, 13a and 13b of the respective rows of the inner race 12 and the outer race 14. A large diameter side contact angle and a small diameter side contact angle are set to 25° to 45°. Assuming a ball diameter of a ball as DW, a groove curvature diameter of the raceway surfaces of the inner race as Di and a groove curvature diameter of the raceway surfaces of the outer race as Do, 1.04DW≤Di≤1.06DW is realized, and 1.08DW≤Do≤1.10DW is realized. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tandem type double row angular contact ball bearing.

  As the bearing, there is an angular ball bearing capable of applying a radial load and an axial load in one direction. The ball and the inner ring / outer ring have a contact angle. The larger the contact angle, the greater the load capacity of the axial load, and the smaller the contact angle, the more advantageous for high-speed rotation.

  By the way, in order to reduce rolling resistance, there is a double row angular contact ball bearing (tandem type) as an alternative to the tapered roller bearing (Patent Document 1). In addition, there is one in which this tandem type double row angular ball bearing is used for an automobile transfer (Patent Document 2). A transfer is a 4WD vehicle that transmits the power coming from the transmission to the front and rear wheels. Usually, a differential device (differential device) is also built in. I'm calling. A double row angular contact ball bearing is a structure in which a single row angular contact ball bearing is combined on the back and the inner ring and outer ring are integrated into one body, so that it can load an axial load in both directions, and has a load capacity for moment load. It is a certain bearing.

As shown in FIG. 3, the tandem type double-row angular ball bearing includes an inner ring 2 having double-row raceway surfaces 1a and 1b, and double-row raceway surfaces 3a and 3b corresponding to the raceway surfaces 1a and 1b of the inner ring 2. And an outer ring 4 and double-row ball groups 5 and 6 interposed between the raceways 1a, 1b, 3a and 3b of each row of the inner ring 2 and the outer ring 4. The double row ball groups 5 and 6 have different pitch circle diameters. The balls 7 and 8 of the ball groups 5 and 6 are held by cages 9 and 10 disposed between the inner ring 2 and the outer ring 4.
Patent No. 181547 JP 2004-183745 A

  That is, the tandem double-row angular contact ball bearing has a structure in which the assembly of the inner ring 2 and the balls 7 and 8 and the cages 9 and 10 and the outer ring 4 can be separated from each other. It is the same and easy to handle. Therefore, this tandem double-row angular ball bearing is used in place of the tapered roller bearing for the purpose of reducing torque.

  However, the tandem double-row angular contact ball bearing is inferior in axial rigidity to the tapered roller bearing of the same size. In the tandem double-row angular contact ball bearing, in order to increase the axial rigidity, it is necessary to increase the contact angle. However, increasing the contact angle makes it easier for the ball (steel ball) to ride on the shoulder. In this way, if the shoulder rises, the bearing life may be reduced.

  In view of the above problems, the present invention provides a tandem double-row angular contact ball bearing that can increase the axial rigidity and prevent the ball (rolling element) from climbing over the shoulder.

  The tandem double-row angular contact ball bearing of the present invention includes an inner ring having a double-row raceway surface, an outer ring having a double-row raceway surface corresponding to the raceway surface of the inner ring, and a raceway surface between each row of the inner ring and the outer ring. In addition, in the tandem type double row angular contact ball bearing provided with a double row ball group interposed with different pitch circle diameters, the contact angle on the large diameter side and the contact angle on the small diameter side are 25 ° or more and 45 ° or less. When the ball diameter of the balls of the ball group is set to DW, the groove curvature diameter of the raceway surface of the inner ring is Di, and the groove curvature diameter of the raceway surface of the outer ring is Do, 1.04 DW ≦ Di ≦ 1. 06DW and 1.08DW ≦ Do ≦ 1.10DW.

  According to the tandem double-row angular contact ball bearing of the present invention, the contact angle on the large diameter side and the contact angle on the small diameter side are 25 ° or more and 45 or less, and the contact angle is large. In addition, the curvature diameters of the raceway surface of the inner ring and the raceway surface of the outer ring are larger than the ball diameter of the ball (rolling element). Moreover, the curvature diameter of the raceway surface of the outer ring is larger than the curvature diameter of the raceway surface of the inner ring.

  In the present invention, the contact angle can be increased, and the axial rigidity can be increased. In addition, since the curvature diameters of the raceway surface of the inner ring and the raceway surface of the outer ring are larger than the ball diameter of the ball (rolling element), it is possible to prevent the ball from climbing over the shoulder. By the way, in general, the axial load applied to the outer ring is larger than the axial load applied to the inner ring. It is possible to effectively prevent the ball from climbing from the surface. For this reason, as a tandem type double row angular contact ball bearing, it is of high quality and exhibits its function stably over a long period of time.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a tandem double-row angular contact ball bearing according to the first embodiment. The tandem double-row angular contact ball bearing includes an inner ring 12 having double-row raceway surfaces 11a and 11b, and a raceway surface 11a of the inner ring 12; The outer ring 14 having double-row raceway surfaces 13a and 13b corresponding to 11b, and the double-row ball groups 15 and 16 interposed between the raceways 11a, 11b, 13a and 13b of each row of the inner ring 12 and the outer ring 14 With. The balls 15 and 16 have different pitch circle diameters (PCD) D1 and D2, respectively. In this case, D1> D2.

  The inner ring 12 has a first cutout portion 21 formed on the outer diameter surface thereof, and a second cutout portion 22 formed in the first cutout portion 21. And the edge part by the side of the 2nd notch of the 1st notch part 21 is made into the said track surface 11a, and the 2nd notch part 22 is made into the said track surface 11b. Further, a circumferential groove 23 is formed on the first notch 21 on the second notch 22 side.

  The outer ring 14 has a first notch 24 formed on the inner diameter surface thereof, and a second notch 25 is formed in the first notch 24. The end of the first notch 24 on the second notch side is the track surface 13a, and the second notch 25 is the track surface 13b.

  The balls of the ball groups 15 and 16 are held by cages 19 and 20, respectively. The large-diameter side retainer 19 is formed of a short cylindrical body in which pockets 40 are formed at a predetermined pitch along the circumferential direction, and balls (steel balls) 27 constituting the ball group 15 are held in each pocket 40. The small-diameter side retainer 20 includes a short cylindrical main body portion 42 in which pockets 41 are formed at a predetermined pitch along the circumferential direction, an inner flange portion 43 provided at the large-diameter side end of the main body portion 42, and And an outer casing 44. A ball (steel ball) 28 constituting the ball group 16 is held in each pocket 41. The inner flange 43 of the cage 20 is fitted in the circumferential groove 23 of the inner ring 12.

  The cages 19 and 20 are resin cages. This resin is preferably an engineering plastic. Here, the engineering plastic is an abbreviation for engineering plastics, which is excellent in heat resistance among synthetic resins and can be used in fields where strength is required. Engineering plastics include general-purpose engineering plastics and super engineering plastics. The engineering plastics used for the cages 19 and 20 include both. The following are typical examples. These are examples of engineering plastics, and engineering plastics are not limited to the following. The resin holders 19 and 20 can be formed by injection molding, for example.

  General-purpose engineering plastics include polycarbonate (PC), polyamide 6 (PA6), polyamide 66 (PA66), polyacetal (POM), modified polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), and GF reinforced polyethylene terephthalate (GF). -PET), ultra high molecular weight polyethylene (UHMW-PE) and the like. Super engineering plastics include polysulfone (PSF), polyethersulfone (PES), polyphenylene sulfide (PPS), polyarylate (PAR), polyamideimide (PAI), polyetherimide (PEI), polyetheretherketone. (PEEK), liquid crystal polymer (LCP), thermoplastic polyimide (TPI), polybenzimidazole (PBI), polymethylbenten (TPX), poly 1,4-cyclohexanedimethylene terephthalate (PCT), polyamide 46 (PA46), There are polyamide 6T (PA6T), polyamide 9T (PA9T), polyamide 11,12 (PA11,12), fluororesin, polyphthalamide (PPA) and the like.

  In this bearing, the contact angle α1 on the large diameter side and the contact angle α2 on the small diameter side are set to 25 ° or more and 45 ° or less. That is, 25 ° ≦ α1 ≦ 45 ° and 25 ° ≦ α2 ≦ 45 °. In this case, α1 <α2. Further, when the ball diameter of the balls 27 and 28 is DW, the groove curvature diameter of the raceway surfaces 11a and 11b of the inner ring 12 is Di, and the groove curvature diameter of the raceway surfaces 13a and 13b of the outer ring 14 is Do. 04DW ≦ Di ≦ 1.06DW and 1.08DW ≦ Do ≦ 1.10DW.

  In the present invention, since the contact angle α1 on the large diameter side and the contact angle α2 on the small diameter side are set to 25 ° or more and 45 or less, the contact angle can be increased and the axial rigidity can be increased. In addition, the curvature diameters of the raceways 11a and 11b of the inner ring 12 and the raceways 13a and 13b of the outer ring 14 are larger than the ball diameters of the balls (rolling elements) 27 and 28. it can. In general, the axial load applied to the outer ring is larger than the axial load applied to the inner ring. It is possible to effectively prevent the ball from climbing over the shoulder. For this reason, as a tandem type double row angular contact ball bearing, it is of high quality and exhibits its function stably over a long period of time.

  Further, since the cages 19 and 20 are resin cages, they are light in weight and have a small coefficient of friction, which is suitable for reducing torque loss and cage wear when starting the bearing. In particular, since the resin cage can be formed by injection molding, there is an advantage that even a cage having a unique shape can be easily manufactured.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the number of balls 27 and 28 of the ball groups 15 and 16 and the ball diameter Etc. can be arbitrarily changed as long as they have the same spherical diameter. The cages 19 and 20 may be iron plate cages (formed by punching a metal plate). As the metal plate, rolled steel plate such as cold rolled steel plate (SPC) and hot rolled mild steel plate (SPH), spring steel, and the like can be used. In the case of a cold rolled steel plate (SPC) or a hot rolled mild steel plate (SPH), it is preferable to subject the surface to surface hardening treatment such as carbonitriding treatment or gas soft nitriding treatment. By making the cages 19 and 20 made of iron plate, the rigidity of the cage can be increased, and the balls 27 and 28 can be stably held over a long period of time. Moreover, it is excellent in oil resistance and can prevent material deterioration due to immersion in oil. The tandem double-row angular contact ball bearing can achieve compactness without reducing the load capacity, and can be used for various machines, devices, tools, and the like. Furthermore, the difference between the pitch circle diameters D1 and D2 of the ball groups 15 and 16 can be variously changed according to the machine, device, tool, and the like to be used.

  Examples will now be described. In this case, as shown in Table 1 below, the contact angle is 15 °, the curvature diameter of the raceway surface 11a (11b) on the inner ring 12 side is 1.02 DW, and the raceway surface 13a (13b) on the outer ring 14 side. The curvature diameter of the inner ring 12 is 1.04 DW, the contact angle is 25 °, the curvature diameter of the raceway surface 11a (11b) on the inner ring 12 side is 1.02 DW, and the raceway surface 13a (13b) on the outer ring 14 side. And the curvature diameter of the raceway surface 11a (11b) on the inner ring 12 side is 1.04 DW, and the raceway surface 13a (13b) on the outer ring 14 side is set to 1.04 DW. The ratio of the shoulder diameter to 1.08 DW was examined for the ratio of the shoulder diameter. In Table 1, a positive numerical value in the shoulder climbing ratio column is a ratio that is raised, and a negative numerical value is a percentage that is not raised.

  As can be seen from this result, shoulder contact does not occur if the contact angle is as small as 15 °, but shoulder contact occurs if the contact angle is as large as 25 ° and the curvature diameter of the raceway surface is small. On the other hand, even if the contact angle is as large as 25 °, shoulder rise does not occur if the curvature diameter of the raceway surface is large.

It is a principal part expanded sectional view of the tandem type double row angular contact ball bearing which shows the embodiment of the present invention. It is principal part sectional drawing of the said tandem type double row angular contact ball bearing. It is sectional drawing of the conventional tandem type double row angular contact ball bearing.

Explanation of symbols

11 a raceway surface 11 b raceway surface 12 inner ring 13 a raceway surface 13 b raceway surface 14 outer ring 15 ball group 16 ball group 19 cage 20 cage 27 ball 28 ball

Claims (1)

An inner ring having a double-row raceway surface, an outer ring having a double-row raceway surface corresponding to the raceway surface of the inner ring, and a raceway surface in each row of the inner ring and the outer ring are interposed with different pitch circle diameters. In tandem double row angular contact ball bearings with double row balls,
The contact angle on the large diameter side and the contact angle on the small diameter side are set to 25 ° to 45 °, the ball diameter of the ball group is DW, the groove curvature diameter of the raceway surface of the inner ring is Di, and the raceway of the outer ring A tandem double-row angular contact ball bearing characterized in that 1.04 DW ≦ Di ≦ 1.06 DW and 1.08 DW ≦ Do ≦ 1.10 DW when the groove curvature diameter of the surface is Do.

Images