JP2009058007A - 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 whose load capacity can be increased by increasing the number of ball, furthermore enabling improved strength of a retainer, and a differential device using such a tandem type double-row angular ball bearing. <P>SOLUTION: The tandem type double-row angular ball bearing comprises: an inner ring 12 including double-row truck surfaces 11a and 11b, an outer ring 14 including double-row truck surfaces 13a and 13b corresponding to the truck surfaces 11a and 11b of this inner ring 12, double-row ball groups 15 and 16 which are interposed in such a manner of different pitch circle diameter between each row of the track surfaces 11a and 11b of the inner ring 12 and each row of the truck surfaces 13a and 13b of the outer ring 14, and resin retainers 19 and 20 holding each ball 27 and 28 of the ball groups 15 and 16, respectively. Furthermore, a resin constituting the resin retainers 19 and 20 by 30 weight% or more and 70 weight% or less with a resin reinforcement material is filled. <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. 4, the tandem double-row angular contact 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. 5, the differential device described in Patent Document 2 includes a differential case 101, a differential reduction mechanism (not shown) arranged 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

  The tandem double-row angular contact ball bearing has a structure in which the assembly of the inner ring 2, balls 7, 8 and cages 9, 10 can be separated from the outer ring 4, and its handling is the same as that of a tapered roller bearing. Yes, there is no change to the differential integration and handling. 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 ball bearing is advantageous in terms of torque over the roller bearing, but the load capacity is greatly reduced, and the following problems are raised. If a tandem double-row angular contact ball bearing of the same size as a tapered roller bearing is used, the load capacity is reduced. If a tandem double-row angular contact ball bearing with the same load capacity as a tapered roller bearing is used, the size increases.

  In view of the above problems, the present invention provides a tandem type double row angular contact ball bearing capable of increasing the load capacity by increasing the number of balls and improving the strength of the cage, and such a tandem type double ball bearing. A differential device using a row angular contact ball bearing is provided.

  One tandem type 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 in each row of the inner ring and the outer ring. In a tandem type double row angular contact ball bearing having a double row ball group interposed between the surfaces with different pitch circle diameters and a resin cage for holding each ball of the ball group, a resin cage Is filled with a resin reinforcing material in an amount of 30 wt% to 70 wt%.

  According to one tandem type double row angular contact ball bearing of the present invention, the resin constituting the resin cage is filled with a resin reinforcing material at 30 wt% or more and 70 wt% or less. Can be improved. For this reason, even if the thickness dimension of the pillar part between the pockets holding the ball is small, the strength as the cage can be maintained. Therefore, by reducing the wall thickness of the column portion between the pockets, the number of pockets can be increased and the number of balls can be increased.

  Another 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 in each row of the inner ring and the outer ring. In a tandem type double row angular contact ball bearing having a double row ball group interposed between the surfaces with different pitch circle diameters and a resin cage for holding each ball of the ball group, a resin cage Is filled with a resin reinforcing material in an amount of 50 wt% to 70 wt%.

  Since the resin constituting the resin cage is filled with a resin reinforcing material at 50 wt% or more and 70 wt% or less, the strength of the cage can be further improved. For this reason, it is possible to stably increase the number of balls.

  The resin reinforcing material may be a fiber reinforced plastic (FRP) such as carbon fiber or glass fiber. Here, the carbon fiber is a fiber made by carbonizing an acrylic fiber or pitch (by-products such as petroleum, coal, coal tar, etc.) at a high temperature. Carbon fibers using the former raw material are classified as PAN (Polyacrylonitrile), and carbon fibers using the latter are classified as PITCH. It is an aggregate of carbon in a broad sense. High strength is obtained by the combination of graphite. Graphite is an elemental mineral consisting of carbon. Carbon fiber is excellent in wear resistance, heat resistance, thermal stretchability, acid resistance, electrical conductivity, tensile resistance, and the like, and has an advantage of being lighter than metals such as aluminum. Further, the glass fiber is a fibrous material made by thinly stretching a molten glass and rapidly solidifying it. They are classified into long fibers and short fibers according to the fiber type, and are roughly classified into alkali glass fibers and alkali-containing glass fibers according to the composition. Glass fiber is excellent in corrosion resistance, heat resistance, moisture resistance, and electrical insulation. For this reason, it becomes a lightweight and strong raw material by mixing carbon fiber and glass fiber with resin.

  The cage is preferably a window type having a pocket for holding the ball.

  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 any of the tandem double-row angular ball bearings described above.

  In the tandem double-row angular contact ball bearing of the present invention, the number of balls can be increased (ball filling rate improved), and the load capacity can be increased. In this case, as the ball filling rate increases, the cage space becomes smaller compared to the standard product, so the width (wall thickness) of the cage column becomes smaller (absolute wall thickness decreases) and the strength increases. descend. However, by filling the resin reinforcing material with 30% by weight or more, the strength that can be used as a cage can be maintained, and stable ball holding is possible. If the filling amount (filling ratio) of the resin reinforcing material exceeds 70% by weight, the resin reinforcing material becomes brittle (decrease in ductility) and becomes brittle. Therefore, the filling amount of the resin reinforcing material is set to 70% by weight or less.

  The resin reinforcing material may be carbon fiber, glass fiber, or the like, and the resin to be used becomes a light and strong material. For this reason, it is possible to stably improve the strength of the cage.

  By making the cage a window type, the width dimension of the pillar portion between the pockets can be increased (thickened), and the strength of the cage can be improved. In addition, so-called “clogging” such as a deep groove ball bearing is not required, and the window-type cage is suitable for a cage of an angular ball bearing.

  The differential device of the present invention uses a tandem double-row angular contact ball bearing that increases the load capacity and can maintain its strength as a cage and can stably exhibit its function over a long period of time. The differential apparatus which exhibits 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.

  Balls 27 of ball groups 15 and 16 are held by cages 19 and 20, respectively. The cages 19 and 20 are formed of short cylindrical bodies in which pockets 30 and 31 are formed at a predetermined pitch along the circumferential direction, and balls (steel balls) 27 that constitute ball groups 15 and 16 in the pockets 30 and 31, 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.

  As shown in FIG. 2, one bearing 56 disposed on the pinion gear 54 side is in contact with the end surface 54a of the pinion gear 54 of the pinion shaft 55 and the end portion 33 of the inner ring 12 of the bearing 56, that is, the end surface 12a, and the outer ring. The end surface 14 a on the side opposite to the pinion gear 14 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.

  The resin constituting the resin cage is filled with a resin reinforcing material at 30 wt% or more and 70 wt% or less. Here, the resin reinforcing material may be a fiber reinforced plastic (FRP) such as carbon fiber (CF) or glass fiber (GF). Here, the carbon fiber is a fiber made by carbonizing an acrylic fiber or pitch (by-products such as petroleum, coal, coal tar, etc.) at a high temperature. Carbon fibers using the former raw material are classified as PAN (Polyacrylonitrile), and carbon fibers using the latter are classified as PITCH. It is an aggregate of carbon in a broad sense. High strength is obtained by the combination of graphite. Graphite is an elemental mineral consisting of carbon. Carbon fiber is excellent in wear resistance, heat resistance, thermal stretchability, acid resistance, electrical conductivity, tensile resistance, and the like, and has an advantage of being lighter than metals such as aluminum. Further, the glass fiber is a fibrous material made by thinly stretching a molten glass and rapidly solidifying it. They are classified into long fibers and short fibers according to the fiber type, and are roughly classified into alkali glass fibers and alkali-containing glass fibers according to the composition. Glass fiber is excellent in corrosion resistance, heat resistance, moisture resistance, and electrical insulation. For this reason, it becomes a lightweight and strong raw material by mixing carbon fiber and glass fiber with resin.

  In the tandem double-row angular contact ball bearing of the present invention, the resin constituting the cages 19 and 20 is filled with a resin reinforcing material at 30 wt% or more and 70 wt% or less. Can be improved. For this reason, even if the thickness dimension of the column part between the pockets holding the balls 27 and 28 is small, the strength as the cages 19 and 20 can be maintained. Therefore, by reducing the wall thickness of the column portion between the pockets, the number of pockets can be increased and the number of balls can be increased. That is, as the ball filling rate increases, the cage space becomes smaller than that of the standard product, so the width (thickness) of the pillars of the cages 19 and 20 becomes smaller (the absolute thickness decreases), Strength decreases. However, by filling the resin reinforcement with 30% by weight or more, the strength that can be used as the cages 19 and 20 can be maintained, and the balls 27 and 28 can be stably held. If the filling amount (filling ratio) of the resin reinforcing material exceeds 70% by weight, the resin reinforcing material becomes brittle (decrease in ductility) and becomes brittle. Therefore, the filling amount of the resin reinforcing material is set to 70% by weight or less.

  The resin reinforcing material may be carbon fiber or glass fiber, and these make the resin used light and strong. For this reason, it is possible to stably improve the strength of the cage.

  Moreover, by making the cages 19 and 20 window-shaped, the width dimension of the column portion between the pockets can be increased (thickened), and the strength of the cages 19 and 20 can be improved. In addition, so-called “clogging” such as a deep groove ball bearing is not required, and the window-type cage is suitable for a cage of an angular ball bearing.

  In the differential device of the present invention, since the load capacity is increased, the strength as the cages 19 and 20 can be maintained, and the tandem double-row angular contact ball bearing that can stably exhibit its function over a long period of time is used. A differential device that exhibits stable functions can be provided.

  The resin constituting the resin cage may be filled with a resin reinforcing material at 50 wt% or more and 70 wt% or less. Thus, if the resin reinforcing material is 50% by weight or more, the strength of the cage can be further improved. For this reason, it is possible to stably increase the number of balls.

  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 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.

  As the reinforcing material to be filled, in addition to CF and GF, an aramid fiber that is a resin fiber having high strength may be used. Here, an aramid fiber is a polyamide fiber whose molecular skeleton is composed of an aromatic (benzene ring).

Next, Example 1 is shown. In Example 1, the relationship between the filling rate of the reinforcing material and the tensile strength was examined. In this case, the tensile strength of samples (test pieces) a, b, c, and d as shown in Table 1 below was examined. Sample a has a reinforcing material filling rate of 10% by weight, sample b has a reinforcing material filling rate of 25% by weight, sample c has a reinforcing material filling rate of 30% by weight, and sample d has a reinforcing material filling rate. The filling rate is 50% by weight. Note that PA66 (polyamide 66 = nylon 66) was used as the resin, and GF was used as the reinforcing material. Each sample a, b, c, d was a test piece based on JIS.

  As shown in Table 1 and FIG. 3, the tensile strength ratio (ratio to the sample not filled with reinforcing material) is 1 for sample a, 1.4 for sample b, and 1.6 for sample c. Yes, in sample d it was 2.1. Thus, the tensile strength increases as the filling rate increases.

Next, Example 2 is shown. In this case, the standard number of balls (11) used in the conventional double row angular contact ball bearing was compared with the strength of the cage when the number of balls was increased by one more than this standard number of balls. The results are shown in Table 2 below. Table 2 shows the strength when the number of standard balls is 1 and the sample not filled with the reinforcing material is 1.

  When the reinforcement is filled at 10% by weight with the standard number of balls, the standard number of balls is the same as when the reinforcement is not filled. If only one ball is added, the reinforcement is filled at the standard number of balls. Although it did not do, it became 0.88-0.92. When the reinforcement is filled with 25% by weight with the standard number of balls, the standard number of balls is the same as when the reinforcement is not filled. If only one ball is added, the reinforcement is not filled. It became 0.88-0.92. When the reinforcing material was filled at 25% by weight with the standard number of balls, if only one ball was added, the reinforcing material was filled at 10% by weight with the standard number of balls, which was 1.67 to 1.78. When the reinforcing material was filled with 50% by weight with the standard number of balls, if only one ball was added, the reinforcing material was filled with 25% by weight with the standard number of balls, which was 1.19 to 1.24.

  Thus, if the reinforcing additive (resin reinforcing material) is 10% by weight with the standard number of balls, by filling 30% by weight of the reinforcing additive, the strength becomes higher than the cage strength of the standard number of balls, and the strength decreases. It becomes possible to prevent. Further, if the reinforcing additive in the standard number of balls is 25% by weight, filling with 50% by weight of the reinforcing additive makes the strength of the cage more than the standard number of balls and prevents the strength from being lowered. .

It is sectional drawing of the tapered roller bearing which shows embodiment of this invention. It is principal part sectional drawing of the differential apparatus using the tapered roller bearing of the said FIG. It is a graph which shows the relationship between a reinforcement filling rate and tensile strength ratio. It is sectional drawing of the conventional tapered roller bearing. It is principal part sectional drawing of the differential apparatus using the conventional tapered roller 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 30, 31 Pocket 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 double-row angular contact ball bearing comprising a double-row ball group and a resin cage that holds each ball of the ball group,
A tandem type double-row angular ball bearing, wherein a resin constituting a resin cage is filled with a resin reinforcing material in an amount of 30 wt% to 70 wt%. 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 double-row angular contact ball bearing comprising a double-row ball group and a resin cage that holds each ball of the ball group,
A tandem type double-row angular ball bearing characterized in that a resin reinforcing material is filled in a resin constituting a resin cage in an amount of 50 wt% to 70 wt%.   The tandem double-row angular contact ball bearing according to claim 1 or 2, wherein the resin reinforcing material is carbon fiber.   The tandem double-row angular ball bearing according to claim 1 or 2, wherein the resin reinforcing material is glass fiber.   The tandem type double-row angular ball bearing according to any one of claims 1 to 4, wherein the cage is a window type having a pocket for holding a ball. 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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