JP2009024845A - Tandem type angular ball bearing and differential device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential device superior in oil resistance, capable of preventing reduction in strength in use, and capable of lengthening the service life of a bearing; and a tandem type double row angular ball bearing suitably usable for this differential device. <P>SOLUTION: This tandem type angular ball bearing has an inner race 12 having raceway surfaces 11a and 11b, 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, ball groups 15 and 16 of double rows interposed with respectively different pitch circle diameters between the raceway surfaces of the respective rows of the inner race 21 and the outer race 14, and resin cages 19 and 20 for holding balls 27 and 28 of the ball groups 15 and 16. Resin used for the cages 19 and 20 is formed of highly oil resistant engineering plastic. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tandem 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 a tapered roller bearing. In addition, there is one in which this tandem type double row angular ball bearing is used for an automobile transfer (Patent Document 1). 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.

  FIG. 3 shows a tandem double-row angular contact ball bearing. Double-row angular contact ball bearings are single-row angular contact ball bearings combined on the back, and the inner ring and outer ring are integrated into one body, which can load axial loads in both directions, and has load capacity for moment loads. It is. As shown in FIG. 3, the inner ring 2 having double-row raceway surfaces 1a and 1b, the outer ring 4 having double-row raceway surfaces 3a and 3b corresponding to the raceway surfaces 1a and 1b of the inner ring 2, the inner ring 2 and A double row ball group 5, 6 interposed between the raceway surfaces 1a, 1b, 3a, 3b of each row of the outer ring 4 is provided, and the double row ball groups 5, 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 1 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.

By the way, since the cages 9 and 10 can be mass-produced by injection molding, those made of resin are often used.
Special table 2002-523710

  Tandem angular contact ball bearings are often used in differentials, and oils that are highly aggressive to resins (oils rich in phosphorus and sulfur) are often used for differentials. However, if the resin cage is used in oil containing a large amount of phosphorus or sulfur, there is a risk that phosphorus or sulfur may enter the resin material. As described above, when phosphorus or sulfur enters the resin material, there is a risk that the strength of the cage is extremely reduced.

  In view of the above-described problems, the present invention is excellent in oil resistance, can prevent a decrease in strength during use, and can be suitably used for a differential device capable of extending the life of a bearing and the differential device. Provided is a tandem type double row angular contact ball bearing.

  The tandem double row angular contact ball bearing of the present invention includes an inner ring having a raceway surface, an outer ring having a double row raceway surface corresponding to the raceway surface of the inner ring, and a raceway surface of each row of the inner ring and the outer ring, respectively. In a tandem angular contact ball bearing comprising a double row ball group interposed with different pitch circle diameters and a resin cage that holds the balls of the ball group, the resin used in the cage is made of high It is an oil-resistant engineering plastic.

  According to the tandem angular contact ball bearing of the present invention, an engineering plastic having oil resistance is used for the resin used in the cage. Here, the engineering plastic is an abbreviation for engineering plastics, which is mainly used in fields where the heat resistance is excellent and the strength is required among synthetic resins. Engineering plastics include general-purpose engineering plastics and super engineering plastics, and the engineering plastics used for the cage include both. Since the present invention uses engineering plastics that are particularly excellent in oil resistance, the oil resistance of the cage can be improved.

  The resin used for the cage used for the bearing can be PPS (polyphenylene sulfide resin). Here, PPS is a high-performance engineering plastic having a molecular structure in which a phenyl group (benzene ring) and sulfur are alternately repeated. Among engineering plastics, it has particularly high oil resistance and excellent strength and toughness. It is crystalline, has a continuous use temperature of 200 ° C. to 220 ° C., has a high deflection temperature under a high load (1.82 MPa) of 260 ° C. and has excellent heat resistance, and has high tensile strength and bending strength. Since the shrinkage rate during molding is as small as 0.3 to 0.5%, the dimensional stability is good, and the flame retardancy and chemical resistance are also excellent. PPS can be broadly classified into three types: a crosslinked type, a linear type, and a semi-crosslinked type. The cross-linked type is obtained by cross-linking a low molecular weight polymer to increase the molecular weight, and is mainly brittle and reinforced with glass fiber. The straight chain type has a high toughness because it has a high molecular weight by omitting the crosslinking step in the polymerization stage. The semi-crosslinked type has the characteristics of having both a crosslinked type and a linear type characteristic.

  The PPS may contain a reinforcing filler. That is, by combining the reinforcing filler with PPS to form a composite material, the characteristics of the reinforcing filler can be added in addition to the characteristics of PPS.

  The reinforcing filler can be carbon fiber. Carbon fibers include those obtained by firing acrylic fibers and those produced by carbonizing pitch (by-products such as petroleum, coal, coal tar) at high temperatures. Carbon fiber has a particularly high elastic modulus, is lightweight, and has excellent heat resistance, electrical conductivity, chemical resistance, and the like. For this reason, it is possible to provide a cage having a high elastic modulus and the like, a higher strength, and a light weight.

  The reinforcing filler can be glass fiber. Glass fiber is obtained by melting inorganic glass into a fiber shape, and is particularly tough and lightweight.

  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 angular contact ball bearing of each of the inventions.

  According to the differential device of the present invention, the tandem angular contact ball bearing of each of the inventions is rotatably supported in the differential case.

  In the tandem angular contact ball bearing of the present invention, since an engineering plastic with high oil resistance is used, a cage with high oil resistance can be provided. For this reason, it is possible to provide a cage that can prevent the intrusion of phosphorus and sulfur, has high durability, and can prevent a decrease in strength. The tandem angular ball used in this cage The life of the bearing can be extended.

  By using PPS as the resin used for the cage, it is possible to provide a cage with particularly high strength and high durability. The tandem angular ball bearing used for this cage is excellent in oil resistance and in use. The strength can be prevented from lowering, and the life can be effectively extended.

  By combining PPS with a reinforcing filler to form a composite material, the cage can be further strengthened, and the tandem angular ball bearing in which the cage is used can have a longer life.

  When the reinforcing filler is made of carbon fiber, a cage having a high elastic modulus, higher strength, and light weight can be provided. For this reason, the lifetime improvement of the tandem angular contact ball bearing used for this cage can be effectively achieved.

  When the reinforcing filler is made of glass fiber, a cage having high toughness, higher strength, and light weight can be provided. For this reason, the lifetime improvement of the tandem angular contact ball bearing used for this cage can be effectively achieved.

  In the differential device of the present invention, since a bearing using a cage that has high durability and can prevent a decrease in strength is used, the life of the bearing can be extended in the differential device. In addition, the pinion gear-side rolling bearing consisting of double-row angular ball bearings is a tandem type in which the pinion gear side ball group is positioned radially outward from the remaining ball group, so that a pinion gear with greater thrust load is applied. The number of balls in the side ball group can be increased, and the load capacity can be further increased. Therefore, a sufficient load capacity can be obtained while reducing the rotational torque.

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

  FIG. 1 shows a tandem type angular contact ball bearing of the present invention. This tandem type angular contact ball bearing has an inner ring 12 having double row raceway surfaces 11a and 11b, and a double row corresponding to the raceway surfaces 11a and 11b of the inner ring 12. Outer race 14 having raceway surfaces 13a and 13b, double row ball groups 15 and 16 interposed between raceway surfaces 11a, 11b, 13a and 13b in each row of inner ring 12 and outer ring 14, The holders 19 and 20 for holding 16 are provided.

  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.

  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 13b, and the second notch 25 is the track surface 13a.

  The ball groups 15 and 16 are held by holders 19 and 20, respectively. The cages 19 and 20 are made of a synthetic resin formed in a tapered cylindrical ring shape, and a plurality of pockets 32 for holding the balls 27 and 28 are arranged in the circumferential direction at the intermediate portion of the axial width. The windows are arranged side by side. A portion between the pockets 32 and 32 of the cages 19 and 20 is an inclined columnar partition wall 34, and a portion on the smaller diameter side and a portion on the larger diameter side of the pocket 32 have both inner and outer diameter surfaces. A small-diameter annular portion 30 and a large-diameter annular portion 31 are formed in a cylindrical surface shape. Both side surfaces of each partition wall 34 have a spherical shape corresponding to the outer diameters of the balls 27 and 28.

  By the way, the resin used for the cages 19 and 20 is 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), 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), and 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 the present embodiment, PPS (polyphenylene sulfide resin) is used among the engineering plastics. PPS is a high-performance engineering plastic having a molecular structure in which a phenyl group (benzene ring) and sulfur are alternately repeated. Particularly, among engineering plastics, it has high oil resistance and excellent strength and toughness. It is crystalline, continuous use temperature is 200 ° C to 220 ° C, deflection temperature under high load (1.82MPa) is 260 ° C or more, it is excellent in oil resistance in addition to heat resistance, and has tensile strength and bending strength. large. Since the shrinkage rate during molding is as small as 0.3 to 0.5%, the dimensional stability is good, and the flame retardancy and chemical resistance are also excellent. PPS can be broadly classified into three types: a crosslinked type, a linear type, and a semi-crosslinked type. The cross-linked type is obtained by cross-linking a low molecular weight polymer to increase the molecular weight, and is mainly brittle and reinforced with glass fiber. The straight chain type has a high toughness because it has a high molecular weight by omitting the crosslinking step in the polymerization stage. The semi-crosslinked type has the characteristics of having both a crosslinked type and a linear type characteristic.

  PPS contains a reinforcing filler. That is, by combining the reinforcing filler with PPS to form a composite material, the characteristics of the reinforcing filler are added in addition to the characteristics of PPS. In this case, the reinforcing filler is carbon fiber (CF) and contains carbon fiber with respect to PPS. Carbon fibers include those obtained by firing acrylic fibers and those produced by carbonizing pitch (by-products such as petroleum, coal, coal tar) at high temperatures. Carbon fiber has a particularly high elastic modulus, is lightweight, and has excellent heat resistance, electrical conductivity, chemical resistance, and the like. The reinforcing material filling rate of carbon fiber is usually 10 to 30%. In particular, when the number of balls is increased to increase the load capacity, the cage pillar width is reduced and the cage strength is lowered. Therefore, 30 to 70% carbon fiber reinforcement is filled.

  In the present invention, in the tandem angular ball bearing, since the engineering plastic having oil resistance is used for the resin used for the cages 19 and 20, the oil resistance of the cages 19 and 20 can be improved. Therefore, it is possible to provide the cages 19 and 20 that can prevent the intrusion of phosphorus and sulfur, have high durability, and prevent the strength from being lowered. The lifetime of the tandem angular contact ball bearing used can be extended.

  Since the resin used for the cages 19 and 20 used for the bearing is PPS (polyphenylene sulfide resin), the cages 19 and 20 having particularly high strength and high durability can be provided. The tandem angular contact ball bearings 20 and 20 are excellent in oil resistance, can prevent a decrease in strength during use, and can effectively extend the life.

  The PPS contains a reinforcing filler. That is, by combining the reinforcing filler with PPS to form a composite material, the characteristics of the reinforcing filler can be added in addition to the characteristics of PPS. For this reason, the retainers 19 and 20 can be further strengthened, and the tandem angular contact ball bearing used in the retainers 19 and 20 can have a longer life.

  Since the reinforcing filler is made of carbon fiber, it is possible to provide the cages 19 and 20 having a high elastic modulus, higher strength, and light weight. For this reason, it is possible to effectively extend the life of the tandem angular contact ball bearing in which the cages 19 and 20 are used.

  Next, a second embodiment of the tandem angular contact ball bearing of the present invention will be described. In this case, glass fiber (GF) is used as a reinforcing filler and contains glass fiber with respect to PPS. Glass fiber is obtained by melting inorganic glass into a fiber shape, and is particularly tough and lightweight. The glass fiber reinforcing material filling rate is usually 10 to 30%. In particular, when the number of balls is increased to increase the load capacity, the cage pillar width is reduced and the cage strength is lowered. Therefore, 30 to 70% carbon fiber reinforcement is filled.

  For this reason, the tandem angular ball bearing of the second embodiment also has the same effect as the tandem angular ball bearing of the first embodiment. In particular, since glass fiber has high toughness and light weight, the cages 19 and 20 having high toughness, higher strength, and light weight can be provided. For this reason, it is possible to effectively extend the life of the tandem angular contact ball bearing in which the cages 19 and 20 are used.

  Next, FIG. 2 shows a differential device using a tandem angular ball bearing according to the present invention. This differential device includes a differential case 51, a differential reduction mechanism 52 disposed in the differential case 51, and a difference. A pinion gear 54 that meshes with the ring gear 53 of the dynamic reduction mechanism 52 and a pinion shaft 55 that supports the pinion gear 54 are provided, and the pinion shaft 55 is rotatably supported in the differential case 51 via bearings 56 and 57.

  The tandem angular ball bearings shown in FIG. 1 are used for the bearings 56 and 57, respectively. 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.

  In the present invention, since the bearings 56 and 57 using the retainers 19 and 20 that have high durability and can prevent strength reduction are used, the life of the bearings 56 and 57 is extended in the differential device. be able to. Further, the pinion gear side rolling bearing 56 formed of a double row angular ball bearing is a tandem type in which the pinion gear side ball group is positioned radially outward from the remaining ball group, so that a larger thrust load acts. The number of balls of the ball group on the pinion gear side can be increased, and the load capacity can be further increased. Therefore, a sufficient load capacity can be obtained while reducing the rotational torque.

  As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the tandem angular ball bearing is a variety of machines other than the differential device. It can be used for devices, tools, etc. Further, the number of balls 27 and 28 of the ball groups 15 and 16, the diameter of the sphere, and the like can be arbitrarily changed. In the differential apparatus shown in FIG. 2, the tandem angular ball bearing is used. However, either one of the bearings 56 and 57 may be a tapered roller bearing instead of the tandem angular ball bearing.

  An immersion test was performed to measure the oil resistance of PPS. That is, a test piece (the product of the present invention, comparative product 1 and comparative product 2) is immersed in oil, and after 2000 hours, a tensile test is performed on each test piece to measure the tensile strength. The measured value of the tensile strength of each test piece before being immersed in oil was compared. The oil used was Mitsubishi Fuso Super Hypoid Gear Oil SAE90 GL-5. As a result, the product of the present invention containing 7.5% glass fiber in PPS did not change the tensile strength before and after immersion, and the tensile strength did not decrease even after immersion in oil. On the other hand, in the comparative product 1 made of PA66, the tensile strength after immersion was 28% lower than the tensile strength before the test. Further, the comparative product 2 made of PA46 had a tensile strength after the test that was 19% lower than the tensile strength before the test. Thereby, it turned out that the product of the present invention containing glass fiber in PPS has high oil resistance.

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

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

Claims (6)

An inner ring having a raceway surface, an outer ring having a double-row raceway surface corresponding to the raceway surface of the inner ring, and a double-row interlaced between the raceway surfaces of each row of the inner ring and the outer ring with different pitch circle diameters. In a tandem angular contact ball bearing comprising a ball group and a resin cage that holds the balls of the ball group,
A tandem angular contact ball bearing characterized in that the resin used for the cage is a high oil resistance engineering plastic.   2. The tandem angular contact ball bearing according to claim 1, wherein the engineering plastic is PPS.   The tandem angular contact ball bearing according to claim 2, wherein the PPS contains a reinforcing filler.   The tandem angular contact ball bearing according to claim 3, wherein the reinforcing filler is carbon fiber.   4. The tandem angular contact ball bearing according to claim 3, wherein the reinforcing filler is glass fiber. 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 angular ball bearing according to any one of claims 1 to 5.

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