JP2009079680A - Tandem type double-row angular ball bearing and differential device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tandem type double-row angular ball bearing capable of enhancing axial rigidity and preventing a ball from rolling on a shoulder. <P>SOLUTION: A contact angle at a large diameter side and a contact angle at a small diameter side are respectively set at 25°-45°. When a ball diameter of balls 27, 28 of groups 15, 16 of balls is set to DW and a groove curvature diameter of raceway surfaces 11a, 11b of the inner ring 12 is set to Di and a groove curvature diameter of raceway surfaces 13a, 13b of the outer ring 14 is set to Do, both groove curvature diameters satisfy the following relationship; 1.04DW≤Di≤1.06DW, and 1.08DW≤Do≤1.10DW. When a pitch circle diameter at the large diameter side is set to P1 and an external diameter of the inner ring is set to D1, they satisfy D1≥0.89P1. When a pitch circle diameter at the small diameter side is set to P2 and an internal diameter of the outer ring is set to D2, they satisfy D2≤1.10P2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  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.

  As shown in FIG. 4, the differential device described in Patent Document 2 includes a differential case 101, a differential reduction mechanism (not shown) disposed in the differential case 101, and a ring gear (see FIG. And a pinion shaft 105 that supports the pinion gear 104. The pinion shaft 105 is rotatably supported in the differential case 101 via bearings 106 and 107.

  And tandem type double row angular contact ball bearings are used for the bearings 106 and 107, respectively. One bearing 106 disposed on the pinion gear 104 side has a large-diameter side end surface 2a of the inner ring 2 (an end surface protruding to the pinion gear 104 side from the outer ring 4) press-contacts the end surface 104a of the pinion gear 104, and The end surface 4 a on the side opposite to the pinion gear is in pressure contact with a step surface 108 formed on the inner surface of the case 101.

  The other bearing 107 has a large-diameter side end surface 2a of the inner ring 2 (an end surface protruding to the side opposite to the pinion gear from the outer ring 4) press-contacts the end edge 100a of the pinion flange 100, and an end surface 4a of the outer ring 4 on the pinion gear side. The step 101 is in pressure contact with the step surface 109 formed on the inner surface of the case 101. Further, the pinion shaft 105 has a large diameter on the pinion gear 104 side to form a stepped portion 105a, and a sleeve 110 is interposed between the stepped portion 105a and the inner ring 2 of the other bearing 107.

In this case, a preload is applied to the bearings 106 and 107 via the pinion flange 100 by screwing a nut member (not shown) to the threaded portion 111 at the end of the pinion shaft 105. That is, by applying preload to the bearings 106 and 107, the rigidity of the bearing support structure is increased, the position of the pinion shaft 105 is stabilized, and the meshing with the ring gear is improved.
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, the balls 7, 8 and the cages 9, 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 compared 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, when the contact angle is increased, the ball (steel ball) is likely to climb 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 axial rigidity and prevent the ball from climbing over the shoulder, and a differential using such a tandem double-row angular contact ball bearing. Providing equipment.

  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. Tandem type double row angular contact ball bearings having a double row ball group with different pitch circle diameters and a cage for holding each ball of the ball group, the contact angle and the small diameter on the large diameter side The contact angle on the side is 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 groove curvature diameter of the raceway surface of the outer ring is Do. 1.04DW ≦ Di ≦ 1.06DW, 1.08DW ≦ Do ≦ 1.10DW, and the pitch circle diameter on the large diameter side is P1, and the inner ring outer diameter is D1. , D1 ≧ 0.89P1, and the smaller diameter pitch circle When the diameter is P2, and the inner diameter of the outer ring is D2, D2 ≦ 1.10P2.

  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. 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. Further, D1 ≧ 0.89P1 and D2 ≧ 1.10P2. That is, the shoulder height of the inner ring and the outer ring is defined.

  The cage is preferably a window type having a pocket for holding a ball. Thus, by using a window shape, interference between the ball and the shoulder can be prevented.

  The cage can be made of resin. At this time, the resin is preferably an engineering plastic. The cage may be made of metal.

  A differential apparatus of the present invention is a differential apparatus including a differential case, a differential reduction mechanism disposed in the differential case, a pinion gear meshing with a ring gear of the differential reduction mechanism, and a pinion shaft that supports the pinion gear. The pinion shaft is rotatably supported in the differential case by the tandem double-row angular ball bearing according to any one of claims 1 to 5.

  In the tandem double-row angular contact ball bearing of the present invention, the contact angle can be increased, and the axial rigidity can be increased. Moreover, 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, 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, but in the present invention, 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. It is possible to effectively prevent the ball from climbing from the surface. Further, by defining the shoulder height of the inner ring and the outer ring, it is possible to further prevent the shoulder from climbing up. 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.

  By making the cage a window type, it is possible to prevent the ball and the shoulder from interfering with each other and to enable stable rotation. Further, by making the cage made of resin, the weight is reduced and the friction coefficient is reduced, which is suitable for reducing torque loss and cage wear at the time of starting the bearing. In particular, polyamide 66 or an engineering plastic such as polyphenylene sulfide is suitable.

  By making the cage made of metal, the rigidity of the cage can be increased, and the ball 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.

  In the differential apparatus of the present invention, the tandem type double-row angular ball bearing used is of high quality and stably exhibits its function over a long period of time, so that a high quality differential apparatus can be provided.

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

  FIG. 2 shows a differential device according to the present invention. The differential device includes a differential case 51, a differential reduction mechanism 52 disposed in the differential case 51, and a pinion gear meshing with a ring gear 53 of the differential reduction mechanism 52. 54 and a pinion shaft 55 that supports the pinion gear 54, and the pinion shaft 55 is rotatably supported in the differential case 51 via bearings 56 and 57.

  As the bearings 56 and 57, tandem double-row angular ball bearings shown in FIG. 1 are used. The bearings 56 and 57 respectively include an inner ring 12 having double-row raceway surfaces 11a and 11b, an outer ring 14 having double-row raceway surfaces 13a and 13b corresponding to the raceway surfaces 11a and 11b of the inner ring 12, the inner ring 12 and A double-row ball group 15, 16 interposed between the raceway surfaces 11 a, 11 b, 13 a, 13 b of each row of the outer ring 14 is provided. The balls 15 and 16 have different pitch circle diameters P1 and P2, respectively. In this case, P1> P2.

  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. The track surface 11 a is formed in the first cutout portion 21, and the track surface 11 b is formed in the second cutout portion 22.

  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 track surface 13 b is formed in the first cutout portion 24, and the track surface 13 a is formed in the second cutout portion 25.

  The balls 27 and 28 of the ball groups 15 and 16 are held by the cages 19 and 20, respectively. The cages 19 and 20 are formed of short cylindrical bodies having pockets 30 and 31 formed at a predetermined pitch along the circumferential direction, and balls (steel balls) 27 and 22 constituting ball groups 15 and 16 in the pockets 30 and 31, respectively. 28 is held. That is, each cage 19, 20 is a partition wall that connects the large-diameter annular portions 32, 33 and the small-diameter annular portions 34, 35, and the large-diameter annular portions 32, 33 and the small-diameter annular portions 34, 35. 36, 37. The partition walls 36 and 37 are arranged at a predetermined pitch along the circumferential direction, and the pockets 30 and 31 are formed between the partition walls 36 and 37.

One of the bearings 56 disposed on the pinion gear 54 side is in contact with the end portion 33 of the inner ring 12 of the bearing 56, that is, the end surface 12a, on the end surface 54a of the pinion gear 54 of the pinion shaft 55, and the end surface of the outer ring 14 on the side opposite to the pinion gear. 14 a is in pressure contact with a step surface 58 formed on the inner surface of the case 51.

  In the other bearing 57, the end portion 33 of the inner ring 12, that is, the end surface 12 a (the end surface on the opposite flange side) is pressed against the end edge 50 a of the pinion flange 50, and the end surface 14 a of the outer ring 14 on the pinion gear side is on the inner surface of the case 51. It is in pressure contact with the formed step surface 59. A sleeve 60 is interposed between the one bearing 56 and the inner ring 12 of the other bearing 57.

  In this case, a preload is applied to the bearings 56 and 57 via the pinion flange 50 by screwing the nut member 62 into the threaded portion 61 at the end of the pinion shaft 55.

  As described above, the retainers 19 and 20 are so-called window types having window portions at a predetermined pitch in the circumferential direction, and are resin retainers. 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), 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 °. Further, when the spherical diameters of the balls 27 and 28 are DW, the groove curvature diameters of the raceway surfaces 11a and 11b of the inner ring 12 are Di, and the groove curvature diameters of the raceway surfaces 13a and 13b of the outer ring 14 are Do. 04DW ≦ Di ≦ 1.06DW and 1.08DW ≦ Do ≦ 1.10DW. Further, when the pitch circle diameter on the large diameter side is P1 and the outer diameter of the inner ring is D1, D1 ≧ 0.89P1, the pitch circle diameter on the small diameter side is P2, and the inner diameter of the outer ring is D2. , D2 ≦ 1.10P2.

  The cages 19 and 20 may be metal 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 or gas soft nitriding.

  In the tandem double-row angular contact ball bearing of the present invention, 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, so that the contact angle can be increased and axial rigidity can be increased. Can be great. Moreover, since the curvature diameters of the raceway surfaces 11a and 11b of the inner ring 12 and the raceway surfaces 13a and 13b of the outer ring 14 are larger than the ball diameters of the balls 27 and 28, it is possible to prevent the balls 27 and 28 from climbing on the shoulder. Generally, the axial load applied to the outer ring is larger than the axial load applied to the inner ring. However, in the present invention, 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. It is possible to effectively prevent the balls from climbing over the shoulder. Furthermore, by setting D1 ≧ 0.89P1 and D2 ≦ 1.10P2, the shoulder heights of the inner ring 12 and the outer ring 14 can be defined, and by this definition, it is possible to further prevent shoulder climbing. 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, by making the cages 19 and 20 window-shaped, interference between the balls 27 and 28 and the shoulder portion can be prevented, and stable rotation is possible. 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.

  By making the cages 19 and 20 made of metal, 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.

  In the differential apparatus of the present invention, the tandem type double-row angular ball bearing used is of high quality and stably exhibits its function over a long period of time, so that a high quality differential apparatus can be provided.

  As mentioned above, although it demonstrated per embodiment of this invention, this invention is not limited to the said embodiment, A various deformation | transformation is possible, for example, the number of the balls 27 and 28 of the ball groups 15 and 16, and a ball diameter Can be arbitrarily changed as long as they have the same diameter. 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 P1 and P2 of the ball groups 15 and 16 can be variously changed according to the machine, device, tool, etc. used.

Examples will now be described. In this case, as shown in the following Table 1, the sample a has a contact angle of 15 °, and the curvature diameter (groove curvature ratio) of the raceway surface 11a (11b) on the inner ring 12 side is 1.02 DW. The shoulder height (inner ring outer diameter) is φ59.65 mm, the curvature diameter of the raceway surface 13a (13b) on the outer ring 14 side is 1.04 DW, and the shoulder height (outer ring inner diameter) of the outer ring is φ70.2 mm. It is said. Sample b has a contact angle of 25 °, the curvature diameter of the raceway surface 11a (11b) on the inner ring 12 side is 1.02 DW, the shoulder height of the inner ring (inner ring outer diameter) is φ59.65 mm, and the outer ring The curvature diameter of the 14th raceway surface 13a (13b) is 1.04 DW, and the shoulder height (outer ring inner diameter) of the outer ring is φ70.2 mm. Sample c has a contact angle of 25 °, the curvature diameter of the raceway surface 11a (11b) on the inner ring 12 side is 1.04 DW, the shoulder height of the inner ring (inner ring outer diameter) is φ59.65 mm, and the outer ring The curvature diameter of the 14th raceway surface 13a (13b) is 1.08 DW, and the shoulder height (outer ring inner diameter) of the outer ring is φ70.2 mm. In the sample d, the contact angle is 25 °, the curvature diameter of the raceway surface 11a (11b) on the inner ring 12 side is 1.04 DW, the shoulder height of the inner ring (inner ring outer diameter) is φ57 mm, and the outer ring 14 side The curvature diameter of the raceway surface 13a (13b) is 1.08 DW, and the shoulder height (outer ring inner diameter) of the outer ring is φ73 mm. 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 described above, each sample was examined for raising the shoulder when the dynamic axial load rating (0.3 Cor / Y) was applied. As can be seen from the results, the sample c, which is the product of the present invention, did not raise the shoulder on the inner ring and the outer ring. That is, 1.04 DW = Di for the inner ring, 1.08 DW = Do for the outer ring, the shoulder height of the inner ring is φ59.65 mm, and the shoulder height of the outer ring is φ70.2 mm. is there.

It is sectional drawing of the tandem type | mold double row angular contact ball bearing which shows embodiment of this invention. It is principal part sectional drawing of the differential apparatus using the tandem type | mold double row angular contact ball bearing of the said FIG. It is sectional drawing of the conventional tandem type double row angular contact ball bearing. It is principal part sectional drawing of the differential apparatus using the conventional tandem type double row angular contact ball bearing.

Explanation of symbols

11a, 11b Raceway surface 12 Inner ring 13a, 13b Raceway surface 14 Outer ring 15, 16 Ball group 19, 20 Cage 27, 28 Ball 51 Differential case 52 Differential reduction mechanism 53 Ring gear 54 Pinion gear 55 Pinion shaft

Claims (6)

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 a tandem type double row angular contact ball bearing comprising a double row ball group and a cage that holds each ball of the ball group,
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 outer ring raceway When the groove curvature diameter of the surface is Do, 1.04DW ≦ Di ≦ 1.06DW, 1.08DW ≦ Do ≦ 1.10DW, and the pitch circle diameter on the large diameter side is P1, and the inner ring A tandem characterized in that D1 ≧ 0.89P1 when the outer diameter is D1, P2 is the pitch circle diameter on the small diameter side, and D2 ≦ 1.10P2 when the inner diameter of the outer ring is D2. Type double row angular contact ball bearing.   2. The tandem double-row angular contact ball bearing according to claim 1, wherein the cage is a window type having a pocket for holding a ball.   The tandem double-row angular ball bearing according to claim 1, wherein the cage is made of resin.   The tandem double-row angular contact ball bearing according to claim 3, wherein the resin is an engineering plastic.   The tandem type double-row angular contact ball bearing according to any one of claims 1 and 2, wherein the cage is made of metal. A differential device comprising a differential case, a differential reduction mechanism disposed in the differential case, a pinion gear meshing with a ring gear of the differential reduction mechanism, and a pinion shaft that supports the pinion gear,
A differential apparatus, wherein the pinion shaft is rotatably supported in a differential case by the tandem double-row angular ball bearing according to any one of claims 1 to 5.

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