JP5338959B2 - Ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball bearing, capable of preventing a retainer from getting contact with an outer ring in high speed rotation, and preventing increase in rotation torque of the bearing or occurrence of seizure. <P>SOLUTION: An outer diameter side gap C1 is set between an outer circumferential surface of the retainer 14 and an inner circumferential surface of the outer ring 11, and an inner diameter side gap C2 is set between an inner circumferential surface of the retainer 14 and an outer circumferential surface of an inner ring 12. Relation is set as the outer diameter side gap C1 is greater than the inner diameter side gap C2, and a cut 20 for lubricant inflow is provided between an end surface on the lubricant flowing in side of the inner ring 12 and the outer circumferential surface. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a ball bearing, and more particularly, to a ball bearing that supports a rotating support shaft of an automatic transmission of a motor vehicle or a hybrid vehicle drive motor, and a rotating portion of various rotating machine devices such as machine tools.

  In general, in an apparatus such as an automatic transmission of an automobile or a hybrid vehicle drive motor, the lubricating oil is supplied to the ball bearing from the outside by a forced circulation oil supply system that supplies the lubricating oil by pumping it or the like.

  As a conventional ball bearing, for example, a ball bearing 100 as shown in FIG. 16 is widely used (see, for example, Patent Document 1). This ball bearing 100 is capable of rolling between an outer ring 101 having an outer ring raceway surface 101a on the inner peripheral surface, an inner ring 102 having an inner ring raceway surface 102a on the outer peripheral surface, and between the outer ring raceway surface 101a and the inner ring raceway surface 102a. A plurality of balls 103 to be disposed, and a crown-shaped cage 104 that holds the plurality of balls 103 at substantially equal intervals in the circumferential direction.

  The crown-shaped cage 104 is formed by injection molding of synthetic resin. As shown in FIG. 17, the crown-shaped cage 104 has a predetermined interval in the circumferential direction between the annular rim portion 105 and the axial end surface of the rim portion 105. A plurality of column portions 106, pocket portions 107 formed so as to be adjacent to each other between the column portions 106 and holding the plurality of balls 103 so as to be able to roll in the circumferential direction at substantially equal intervals, and pocket portions A pair of claw portions 108 formed at both ends in the circumferential direction of the inner peripheral surface 107 and an opening 109 formed between the respective tips of the pair of claw portions 108 are provided. Then, by pushing the ball 103 into the pocket portion 107 while expanding the pair of claws 108 from the opening 109, the ball 103 is held in the pocket portion 107 so as to be able to roll through a minute gap.

JP 2003-214436 A

  However, when this type of bearing is used at high speed and the ball rotates at high speed, a so-called air curtain action occurs in which the flow rate of oil into the revolution space decreases. As a result, the oil stays and the heat removal action by the oil decreases, so that there is a problem that the bearing temperature rises due to heat generation. This increase in heat generation is a problem to be improved because it is a major factor causing a decrease in strength for a suitable resin cage in terms of self-lubricity, low friction, and the like.

  In particular, ball bearings used in hybrid vehicle drive motors rotate at a high speed of dmN 700,000 or more, so there is a strong tendency to increase the air curtain layer generated by the air around the bearings, and lubricating oil is introduced inside the bearings. It was difficult to cause seizure due to insufficient lubrication.

  The present invention has been made in view of the above-described problems, and its purpose is to reduce the air curtain action that occurs in the revolving part of the ball when rotating at high speed, and to ensure sufficient oil penetrating the bearing. The object of the present invention is to provide a ball bearing capable of suppressing heat generation.

The above object of the present invention can be achieved by the following constitution.
(1) An outer ring having an outer ring raceway groove on the inner peripheral surface, an inner ring having an inner ring raceway groove on the outer peripheral surface, a plurality of balls arranged so as to roll between the raceway grooves, and rolling the balls into pockets. A ball bearing that is oil-lubricated and has a shoulder portion formed on both axial sides of both raceway grooves of the outer ring and the inner ring. At least one of the shoulders of the outer ring and the inner ring has a diameter that increases from the axial end to the inside, and the spatial volume on one side in the axial direction is smaller than the spatial volume on the other side in the axial direction. Ball bearing.
(2) The outer peripheral surface of the shoulder portion of the inner ring on one side in the axial direction has a tapered surface formed so as to expand from the axial end portion toward the inside, and the inner peripheral surface of the shoulder portion of the outer ring on the one side in the axial direction. The ball bearing according to (1), wherein the ball bearing has a tapered surface formed so as to increase in diameter from the axial end portion toward the inside.
(3) The ball bearing according to (1) or (2), wherein both the raceway grooves are offset toward the other side in the axial direction with respect to the axial intermediate position of the bearing.
(4) The ball bearing according to any one of (1) to (3), wherein the retainer has an annular rim portion disposed on one side in the axial direction.
(5) A cage is formed between an annular rim portion, a column portion projecting in the axial direction, and a plurality of cage rim portions arranged at predetermined intervals in the circumferential direction on the axial end surface of the rim portion. (1) to (4), characterized in that it is a crown type retainer having a pocket portion that holds a plurality of balls so as to roll in a circumferential direction at substantially equal intervals. The ball bearing described.
(6) The ball bearing according to (5), wherein the cage is manufactured by a molding die having two or more resin injection gates.

  According to the ball bearing of the present invention, shoulder portions are respectively formed on both sides in the axial direction of the raceway grooves of the inner ring and the outer ring, and at least one shoulder portion of the inner ring and the outer ring on one side in the axial direction is the axis thereof. The air curtain is generated in the revolving part of the ball when rotating at high speed because the diameter of the ball is expanded from the end in the direction toward the inside and the space volume on one side in the axial direction is smaller than the space volume on the other side in the axial direction. The action can be reduced, and sufficient heat can be secured through the bearing to suppress heat generation.

  In addition, the space volume on one side in the axial direction of the present invention refers to the bearing grooves (balls) from the axial end on the one side in the axial direction in the bearing space formed between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. The axial volume on the other side in the axial direction from the axial end on the other side in the axial direction to the axial direction of both raceway grooves (rows). The space volume up to the middle position.

It is principal part sectional drawing for demonstrating 1st Embodiment of the ball bearing which concerns on this invention. It is principal part sectional drawing for demonstrating the flow of the lubricating oil of the ball bearing shown in FIG. It is principal part sectional drawing for demonstrating the 1st modification of the ball bearing of 1st Embodiment. It is principal part sectional drawing for demonstrating the 2nd modification of the ball bearing of 1st Embodiment. It is principal part sectional drawing for demonstrating the 3rd modification of the ball bearing of 1st Embodiment. It is principal part sectional drawing for demonstrating the 4th modification of the ball bearing of 1st Embodiment. It is principal part sectional drawing for demonstrating the 5th modification of the ball bearing of 1st Embodiment. It is principal part sectional drawing for demonstrating the 6th modification of the ball bearing of 1st Embodiment. It is principal part sectional drawing for demonstrating the 7th modification of the ball bearing of 1st Embodiment. It is principal part sectional drawing for demonstrating 2nd Embodiment of the ball bearing which concerns on this invention. It is principal part sectional drawing for demonstrating the 1st modification of the ball bearing of 2nd Embodiment. It is principal part sectional drawing for demonstrating 3rd Embodiment of the ball bearing which concerns on this invention. It is principal part sectional drawing for demonstrating the 1st modification of the ball bearing of 3rd Embodiment. It is principal part sectional drawing for demonstrating the 2nd modification of the ball bearing of 3rd Embodiment. It is principal part sectional drawing for demonstrating the 3rd modification of the ball bearing of 3rd Embodiment. It is principal part sectional drawing which shows the conventional ball bearing. It is a perspective view which shows the crown type holder | retainer integrated in the conventional ball bearing.

  Hereinafter, each embodiment of a ball bearing concerning the present invention is described in detail with reference to drawings. In the following description, the basic structure of the crown type cage incorporated in the ball bearing of this embodiment is the same as that of the conventional crown type cage shown in FIG.

(First embodiment)
First, a first embodiment of a ball bearing according to the present invention will be described with reference to FIG. 1 is a cross-sectional view of a main part for explaining a first embodiment of a ball bearing according to the present invention, FIG. 2 is a cross-sectional view of a main part for explaining the flow of lubricating oil in the ball bearing shown in FIG. FIG. 9 is a cross-sectional view of an essential part for explaining first to seventh modified examples of the ball bearing of the first embodiment.

  As shown in FIG. 1, the ball bearing 10 of the present embodiment is fitted in the housing 1, and is fitted on the outer ring 11 having the outer ring raceway groove 11 a on the inner circumferential surface and the rotary shaft 2, and on the outer ring surface on the inner ring raceway. The inner ring 12 having the groove 12a, the plurality of balls 13 that are rotatably arranged between the outer ring raceway groove 11a and the inner ring raceway groove 12a, and the plurality of balls 13 are held at substantially equal intervals in the circumferential direction. And a synthetic resin crown-shaped cage 14.

  The crown type retainer 14 is manufactured by an injection mold having two or more resin injection gates, and has an annular rim portion 15 and a predetermined interval in the circumferential direction on the axial end surface of the rim portion 15. A plurality of arranged pillar portions 16 projecting in the axial direction and pocket portions 17 formed so as to be adjacent to each other between the pillar portions 16 and holding the plurality of balls 13 so as to be able to roll in the circumferential direction at substantially equal intervals. And a pair of claw portions 18 formed at both ends in the circumferential direction of the inner peripheral surface of the pocket portion 17, and an opening portion 19 formed between the tips of the pair of claw portions 18. Then, by pushing the ball 13 into the pocket portion 17 while expanding the pair of claws 18 from the opening portion 19, the ball 13 is held in the pocket portion 17 so as to be able to roll through a minute gap.

Synthetic resin materials for the crown-shaped cage 14 include, for example, polybutylene terephthalate, polyphenylene sulfide (PPS), polyamideimide (PAI), thermoplastic polyimide, polyether in addition to polyamide resins such as 46 nylon and 66 nylon. Examples include ether ketone (PEEK) and polyether nitrile (PEN). Moreover, the rigidity and dimensional accuracy of the crown type cage 14 can be improved by appropriately adding 10 to 50% by weight of a fibrous filler (for example, glass fiber or carbon fiber) to these resin materials. .

  And in this embodiment, the clearance gap between the outer peripheral surface of the crown type holder | retainer 14 and the inner peripheral surface of the outer ring | wheel 11 is made into the outer diameter side clearance C1, and the inner peripheral surface of the crown type holder | retainer 14 and the outer peripheral surface of the inner ring | wheel 12 When the clearance is the inner diameter side clearance C2, the relationship of the outer diameter side clearance C1> the inner diameter side clearance C2 is satisfied, and the end surface (right end surface in FIG. 1) of the inner ring 12 and the outer peripheral surface of the inner ring 12 are satisfied. Is provided with a notch 20 for lubricating oil inflow.

  In the ball bearing 10 configured as described above, as shown by an arrow A in FIG. 2, the lubricating oil is a gap between the outer peripheral surface of the crown type retainer 14 and the inner peripheral surface of the outer ring 11 and a notch portion of the inner ring 12. 20 flows into the bearing 10, and sufficiently spreads between the outer peripheral surface of the retainer 14 and the inner peripheral surface of the outer ring 11 and between the inner peripheral surface of the retainer 14 and the outer peripheral surface of the inner ring 12. After the inside is lubricated, it flows out to the outside.

  As described above, according to the ball bearing 10 of the present embodiment, the clearance between the outer peripheral surface of the crown-shaped cage 14 and the inner peripheral surface of the outer ring 11 is the outer-diameter-side clearance C1, and the inner circumference of the crown-shaped cage 14 is set. When the clearance between the surface and the outer peripheral surface of the inner ring 12 is the inner diameter side clearance C2, the cage 14 is twisted and deformed by centrifugal force during high speed rotation in order to satisfy the relationship of outer diameter side clearance C1> inner diameter side clearance C2. Even if it does, since the holder | retainer 14 contacts the inner ring | wheel 12 ahead of the outer ring | wheel 11, it can avoid that the holder | retainer 14 contacts the groove shoulder part of the outer ring | wheel 11 which is a sharp edge.

  Further, according to the ball bearing 10 of the present embodiment, the notch 20 for lubricating oil inflow is provided between the end surface of the inner ring 12 on the lubricating oil inflow side and the outer peripheral surface of the inner ring 12, so Since the inflowing lubricating oil is sufficiently distributed between the inner peripheral surface of the cage 14 and the outer peripheral surface of the inner ring 12, an increase in rotational torque of the bearing 10 and occurrence of seizure can be prevented.

  Moreover, according to the ball bearing 10 of this embodiment, since the crown type cage 14 is manufactured by an injection mold having two or more resin injection gates, the cage has an injection having one resin injection gate. Since the roundness of the cage 14 can be improved as compared with the case of manufacturing with a molding die, the factor that the cage 14 slides on the outer ring 11 can be reduced.

  Moreover, according to the ball bearing 10 of this embodiment, since the crown type cage 14 manufactured by an injection mold is adopted as the cage, two synthetic resin annular members are recessed and fitted in the axial direction. Compared to the combined cage, the manufacturing cost can be greatly reduced.

  As a first modification of the present embodiment, as shown in FIG. 3, the end face of the outer ring 11 on the lubricating oil inflow side covers a part of the bearing opening to suppress the inflow of the lubricating oil into the bearing 10. A shielding plate (shielding member) 21 may be provided. Thereby, the inflow of the lubricating oil from the outer peripheral surface side of the crown-shaped cage 14 is suppressed, and the lubricating oil flows more effectively between the inner peripheral surface of the crown-shaped cage 14 and the outer peripheral surface of the inner ring 12. Can be made. In this case, as shown by an arrow B in FIG. 3, the lubricating oil flowing from the inner peripheral surface side of the crown-shaped cage 14 is also supplied to the outer peripheral surface side by centrifugal force, so that the outer peripheral surface side is insufficiently lubricated. There is no.

  Further, as a second modification of the present embodiment, as shown in FIG. 4, as a shielding member, the inner peripheral surface of the end portion of the outer ring 11 on the lubricating oil inflow side covers a part of the bearing opening and enters the bearing. You may make it mount | wear with the shield board 22 which suppresses inflow of this lubricating oil.

Further, as a third modification of the present embodiment, as shown in FIG.
A shielding plate 23 that covers a part of the bearing opening and suppresses the inflow of the lubricating oil into the bearing may be integrally provided in the housing 1 in which is fitted.

  As a fourth modification of the present embodiment, as shown in FIG. 6, the inner peripheral surface of the crown type retainer 14 is gradually directed toward the end surface of the inner ring 12 on the lubricating oil inflow side (notch portion 20 side). The tapered surface 24 may be reduced in diameter. As a result, it is possible to facilitate the inflow and outflow of the lubricating oil by the centrifugal force during the rotation of the bearing, so that the amount of the lubricating oil in the bearing 10 can be properly maintained, and the rotational torque of the bearing 10 is reduced. Can do.

  As a fifth modification of the present embodiment, an R chamfer 25 may be provided at the boundary between the outer peripheral surface of the inner ring 12 and the notch 20 as shown in FIG. As a result, even if the crown-shaped cage 14 is twisted and deformed by the centrifugal force during high-speed rotation and contacts the inner ring 12, the inner peripheral surface of the crown-shaped cage 14 and the R chamfer 25 are in sliding contact with each other. The rotation of the cage 14 is not easily hindered, and wear of the cage due to a sharp edge can be suppressed.

  Further, as a sixth modification of the present embodiment, as shown in FIG. 8, between the end surface on the rim portion 15 side of the crown-shaped cage 14 and the inner peripheral surface of the crown-shaped cage 14, and the crown-shaped cage The chamfered portions 26 may be provided between the end surface of the 14 rim portion 15 side and the outer peripheral surface of the crown type retainer 14. In this case, the bearing end surface on the notch portion 20 side is used as a reference surface, and the axial length of the chamfered portion 26 from the reference surface (cage chamfering length) L1 <the axial length of the notched portion 20 from the reference surface. As the inner ring chamfering length L2, the cutout portion 20 is arranged to extend inward in the axial direction from the chamfered portion 26 of the crown type retainer 14. Thereby, since the inflow of the lubricating oil into the bearing 10 is not hindered by the chamfered portion 26 of the crown type retainer 14, the lubricating oil can be efficiently flowed into the bearing 10 from the notch portion 20.

  As a seventh modification of the present embodiment, a stepped portion 27 may be provided between the notch portion 20 and the outer peripheral surface of the inner ring 12 as shown in FIG.

(Second Embodiment)
Next, with reference to FIG.10 and FIG.11, 2nd Embodiment of the ball bearing which concerns on this invention is described. FIG. 10 is a cross-sectional view of a main part for explaining a second embodiment of the ball bearing according to the present invention, and FIG. 11 is a cross-sectional view of a main part for explaining a first modification of the ball bearing of the second embodiment. . Note that portions that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  In the ball bearing 30 of the present embodiment, as shown in FIG. 10, in the bearing space formed between the inner peripheral surface of the outer ring 11 and the outer peripheral surface of the inner ring 12, the axial intermediate position P of both raceway grooves 11 a and 12 a. On the other hand, the spatial volume from the axial end 11d, 12d on the axial side, which is the side where the rim portion 15 of the cage 14 is located, to the axial intermediate position P of both raceway grooves 11a, 12a (ball train). Is smaller than the space volume from the axial ends 11e, 12e on the other axial side to the axial intermediate position P of both raceway grooves 11a, 12a (ball train).

  Further, shoulder portions 11b, 11c, 12b, and 12c are formed on both axial sides of both raceway grooves 11a and 12a of the outer ring 11 and the inner ring 12, respectively. The inner peripheral surface of the shoulder portion 11b of the outer ring 11 on one side in the axial direction, which is the side where the rim portion 15 of the retainer 14 is located, with respect to the axial intermediate position P of the both raceway grooves 11a, 12a is the axial end portion. It has the taper surface 31 formed so that it may expand from 11d toward the inside. Furthermore, the outer peripheral surface of the shoulder portion 12b of the inner ring 12 on one side in the axial direction has a tapered surface 32 formed so as to increase in diameter from the axial end portion 12d toward the inside.

  In addition, the inclination of each taper surface 31 and 32 is arbitrarily set as long as the relationship that the spatial volume on one side in the axial direction is smaller than the spatial volume on the other side in the axial direction is established.

  The ball bearing 30 is always supplied with lubricating oil from one axial direction by forced circulation oil supply by a pump (not shown) or the like. The ball bearing 30 is disposed such that one side in the axial direction where the rim portion 15 of the crown-shaped cage 14 is disposed faces the oil inflow side, and the lubricating oil flows into the bearing from one side in the axial direction, Outflow from the other direction. In FIG. 10, the arrows indicate the direction of oil flow.

  In this way, the ball bearing 30 disposed in the forced circulation oil supply path can suppress the air curtain action that occurs when used at high speed rotation, and can form an oil flow by the bearing itself. . Further, the pair of tapered surfaces 31 and 32 are inclined in the direction in which the peripheral speed at the tapered surfaces 31 and 32 increases toward the outflow side and the oil flow is accelerated by the pumping action due to the centrifugal force. The heat removal effect can be promoted.

  In addition, in this embodiment, while forming the taper surface 31 in the shoulder part 11b of the outer ring | wheel 11, and forming the taper surface 32 in the shoulder part 12b of the inner ring | wheel 12, the space volume in the axial direction one side is axially other side. However, the present invention is not limited to this, and the above relationship is established by forming a tapered surface on at least one of the shoulder portion 11c of the outer ring 11 and the shoulder portion 12c of the inner ring 12. You may do it. Further, the above relationship may be established by expanding the inner peripheral surface of the shoulder portion 11c of the outer ring 11 with a uniform diameter. In these cases, it is not necessary to form the tapered surfaces 31 and 32 on the outer ring 11 and the inner ring 12, but it is more preferable to form the tapered surfaces 31 and 32 because the above relationship can be further satisfied.

  As a first modification of the present embodiment, as shown in FIG. 11, the axial intermediate position P of both raceway grooves 11a and 12a is offset from the axial intermediate position Q of the ball bearing 30 to the other axial side. The tapered surfaces 31 and 32 of the shoulders 11b and 12b of the outer ring 11 and the inner ring 12 on one side in the axial direction may be formed longer than in the first embodiment. Thereby, the force which pushes lubricating oil into the revolution part of the ball | bowl 13 can be enlarged according to the pump effect | action by centrifugal force, and the heat removal effect by oil can be promoted more.

Further, by forming the rim portion 15 of the retainer 14 disposed between the outer ring 11 on one side in the axial direction and the shoulder portions 11b, 12b of the inner ring 12 in the axial direction, the space volume on the one side in the axial direction is increased in the axial direction. Since it is adjusted so as not to be larger than the space volume on the other side, the air curtain action due to the high-speed rotation of the bearing is reduced. In addition, the retainer 14 can make rigidity high by forming the rim | limb part 15 long in an axial direction. However, it is necessary to design the shape of the tapered surfaces 31 and 32 of the shoulder portions 11b and 12b while preventing the productivity from decreasing due to the interference between the outer ring 11 and the retainer 14 or the thinning of the end portion of the inner ring 12. is there.
Other configurations and operations are the same as those in the first embodiment.

The tapered surface formed on the shoulder of the outer ring or inner ring on one side in the axial direction so as to increase in diameter from the axial end to the inside may be formed to a position adjacent to the track groove. It may be formed up to a position slightly away from the groove.
In addition, the shape of the diameter of the shoulder of the outer ring or inner ring on one side in the axial direction from the end in the axial direction toward the inside may be a tapered shape as in the present embodiment, but a curved surface shape. You can also.

  Moreover, in the said embodiment, although the space volume in the ball bearing 10 is adjusted with the volume of the rim | limb part 15 of the crown type holder | retainer 14, as a holder | retainer, the machined type from which the axial direction width | variety from which an annular part differs differs You may make it adjust the space volume of this invention using a holder | retainer.

(Third embodiment)
Next, with reference to FIGS. 12-15, 3rd Embodiment of the ball bearing which concerns on this invention is described. FIG. 12 is a cross-sectional view of a main part for explaining a third embodiment of the ball bearing according to the present invention, and FIGS. 13 to 15 are key points for explaining first to third modifications of the ball bearing of the third embodiment. FIG. In addition, about the same or equivalent part as 1st and 2nd embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

  The ball bearing 40 according to the present embodiment is a bearing that supports a rotation support shaft such as a drive motor for a hybrid vehicle whose number of revolutions is controlled by an inverter, and as shown in FIG. 12, between the outer ring 11 and the housing 1. Insulating sleeve (insulating layer) 41 having electrical insulation is interposed. The insulating sleeve 41 includes an annular portion 42 having substantially the same width as the axial width of the outer ring 11, and a holed disc portion that extends radially inward from one side surface of the annular portion 42. 43.

  The outer ring 11 is fitted into the annular portion 42 of the insulating sleeve 41, and its axial end portion 11 e is brought into contact with the holed disk portion 43 of the insulating sleeve 41, so that the side surface ( A tapered surface 44 that gradually approaches the axial end portion 11e of the outer ring 11 is formed between the inner circumferential surface and the side surface that is in contact with the outer ring 11.

As the material of the insulating sleeve 41, various materials having electrical insulation can be used, and examples thereof include the following.
(1) Polyphenylene sulfide (PPS) resin containing glass fiber.
(2) It is formed of a polyphenylene sulfide resin containing glass fiber and a non-fibrous insulating inorganic filler, and the content of the glass fiber and the non-fibrous insulating inorganic filler with respect to the polyphenylene sulfide resin is expressed by weight ratio. Those set to 25-60% and 10-40%, respectively, and the total content of both is set to 40-70% by weight.
(3) The insulating coating includes a fiber material [A] that contributes to the reinforcement of the matrix resin and a filler [B] having a thermal conductivity of 10 W / m · K or more and a specific resistance of 10 ¹⁰ Ω · cm or more. The content of the filler [B] is 10 to 40% by weight, and the total [A + B] of both is 30 to 50% by weight. Or the content of the filler [B] is 10 to 50% by weight, and the total [A + B] of both is 20% by weight or more and less than 60% by weight.
(4) The insulating film is made of a synthetic resin composition having a specific resistance of 1 × 10 ³ Ω · cm or more and a thermal conductivity of 0.5 w / m · k or more. The synthetic resin composition is a matrix resin. A fiber material having a thermal conductivity of less than 10 w / m · k and a specific resistance of 1 × 10 ³ Ω · cm or more, a saturation magnetization of 20 emu / g or more, and a specific resistance of 1 × 10 ³ Ω · cm or more of the magnetic filler, the total of the fiber material and the magnetic filler is 50 to 75% by weight, and the insulating coating contains the nonmagnetic high thermal conductive filler, and this nonmagnetic high thermal conductivity The filler is alumina fiber, the magnetic filler is ferrite, and the fiber material is glass fiber (GF) fiber, potassium titanate whisker, aluminum borate whisker, calcium carbonate whisker (argonite), basic magnesium sulfate whisker. Car, and that is one of the aramid fiber.
(5) Polyester elastomer having a dielectric constant of 3 to 6.2 at a dielectric constant of 1 kHz, polyamide elastomer having a dielectric constant of 3.5 to 5 at a dielectric constant of 1 kHz, silicon rubber having a dielectric constant of 3 to 5 at a dielectric constant of 1 kHz, and a dielectric constant of 1 kHz. Sometimes one of a few fluororubbers.
(6) A polytetrafluoroethylene baked film including an insulating layer containing a resin binder selected from a furan resin, an epoxy resin, and a polyamide-imide resin, and a sleeve made of polyphenylene sulfide resin including glass fibers.
(7) A rolling bearing that satisfies the following five conditions:
Condition A: A thermoplastic elastomer layer is formed on the entire outer peripheral portion of the outer ring.
Condition B: The layer of the thermoplastic elastomer has a hardness of 60 to 90 [HDA] and a thickness of 0.5 to 5 mm.
Condition C: The thermoplastic elastomer layer contains a thermally conductive filler having a thermal conductivity of 10 W / m · k or more and a specific resistance of 1 × 10 ⁴ Ω · cm or more.
Condition D: Concavities and convexities are provided over the entire outer periphery of the thermoplastic elastomer layer.
Condition E: The unevenness of condition D is formed by a herringbone-shaped concave portion that continues in the width direction of the outer ring, a strip-shaped concave portion that continues in a rhombus shape, or irregularly-shaped projections that are irregularly scattered. The thermoplastic elastomer layer has a height (depth) of irregularities on the outer peripheral surface of 5 to 100 μm.
(8) Insulating coating PPS resin, glass fiber having a diameter of 5 to 9 μm, and a heat conductive material having a specific resistance of 1 × 10 ¹⁰ Ω · cm or more and a thermal conductivity of 10 W / m · k or more. It consists of a resin composition, the content rate of the glass fiber in this resin composition is 15-40 mass%, and the content rate of a heat conductive substance is 15-45 mass%.

  The rotary shaft 2 to which the inner ring 12 is fitted is formed with an oil supply hole 45 that opens on the outer peripheral surface of the rotary shaft 2, and the ball bearing 40 has a tapered surface 44 of the insulating sleeve 41 and an oil supply hole 45 of the rotary shaft 2. Are arranged at substantially the same position in the axial direction.

  As described above, according to the ball bearing 40 of the present embodiment, the insulating sleeve 41 is provided between the outer ring 11 and the housing 1 to electrically insulate between the housing 1 and the rotating shaft 2. Even if a large potential difference occurs between the housing 1 and the rotating shaft 2 due to high frequency induction during inverter control, no current flows in the ball bearing 40, and both the raceway grooves 11a, 12a and the ball 13 It is possible to prevent electrolytic corrosion generated on the rolling surface of the. Moreover, it is excellent in durability, and the ball bearing 40 suitable for using as a ball bearing for hybrid vehicle drive motors can be obtained.

Further, according to the ball bearing 40 of the present embodiment, the lubricating oil supplied from the oil supply hole 45 is guided to the ball bearing 10 side by the tapered surface 44 of the insulating sleeve 41 as shown by the arrow in FIG. Even if, for example, the ball bearing 10 is used at high speed rotation and an air curtain action occurs, sufficient oil can be secured to penetrate the ball bearing 10, increasing the rotational torque or seizure of the ball bearing 10. Can be prevented.
In addition, about another structure and effect | action, it is the same as that of the thing of 1st and 2nd embodiment.

  In FIG. 12, a cage is omitted, but a crown-type cage, a corrugated press cage, or the like can be used as the cage. In the case of a crown type cage, the direction of the rim portion is not particularly limited, but it is preferable that the rim portion is disposed on the oil supply hole side in consideration of the amount of lubricating oil penetrating the bearing. In the present embodiment, the insulating sleeve 41 is disposed on the outer ring 11 side, but is not limited thereto, and may be disposed on the inner ring 12 side, or may be disposed on both the outer ring 11 and the inner ring 12. It may be.

  As a first modification of the present embodiment, as shown in FIG. 13, instead of the tapered surface 44 of the insulating sleeve 41, the inner peripheral surface of the holed disk portion 43 of the insulating sleeve 41 is arranged on the rotating shaft 2. A stepped portion 46 facing the oil supply hole 45 may be provided.

  As a second modification of the present embodiment, as shown in FIG. 14, the axial thickness of the holed disc portion 43 of the insulating sleeve 41 is increased and the shaft of the rim portion 15 of the crown type retainer 14 is increased. The crown-shaped cage 14 is protruded outward in the axial direction from the ball bearing 10 by increasing the thickness of the direction, or the crown-shaped cage 14 is projected in the axial direction from the ball bearing 10 due to rattling during rotation. May be.

  In this modification, the rim portion 15 of the crown type retainer 14 is positioned above the oil supply hole 45 of the rotating shaft 2. Thereby, the lubricating oil supplied from the oil supply hole 45 hits the inner peripheral surface of the rim portion 15 and is easily supplied into the bearing. Moreover, since the intensity | strength of the crown type holder | retainer 14 is improved by forming the axial direction thickness of the rim | limb part 15 thick, damage can be prevented. If the raceway grooves 11a and 12a of the outer ring 11 and the inner ring 12 are formed offset to the right side in FIG. It is possible to further increase the wall thickness.

  Further, as a third modification of the present embodiment, as shown in FIG. 15, the holed disk portion 43 of the insulating sleeve 41 may be further extended radially inward to have a sealing function. . Further, in the present modification, a cored bar 47 made of metal or the like is placed in the insulating sleeve 41, and the holed disk portion 43 is reinforced. In this modification, O-rings 48 and 48 are disposed on the outer peripheral surface of the insulating sleeve 41, and the occurrence of creep with the housing 1 is prevented. Furthermore, in this modification, a chamfered portion 49 is formed at the outer peripheral corner portion of the insulating sleeve 41, and the insertability of the ball bearing 40 into the housing 1 is improved.

  In this modification, the holed disc portion 43 of the insulating sleeve 41 is arranged on the left side of the ball bearing 40, but it may be arranged on both axial sides of the ball bearing 40.

In addition, this invention is not limited to what was illustrated by said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, in each of the above embodiments, the general case where the ball bearing is used for inner ring rotation and outer ring fixing has been described, but the present invention is also applicable to the case where it is used for inner ring fixing and outer ring rotation.
Moreover, in each said embodiment, although the holder | retainer was the ball guide system, an outer ring guide or an inner ring guide may be sufficient.
The ball bearing may be a deep groove ball bearing or an angular deep groove ball bearing.
Moreover, each said embodiment can be combined in the range which can be implemented.

DESCRIPTION OF SYMBOLS 1 Housing 2 Rotating shaft 10 Ball bearing 11 Outer ring 11a Outer ring raceway groove 12 Inner ring 12a Inner ring raceway groove 13 Ball 14 Crown type cage 15 Rim part 16 Column part 17 Pocket part 19 Opening part 20 Notch part 21 Shielding plate (shielding member)
22 Shield plate (shielding member)
23 Shield plate (shield member)
24 Tapered surface 25 R Chamfered portion 26 Chamfered portion C1 Outer diameter side clearance C2 Inner diameter side clearance 30 Ball bearing 31 Tapered surface 32 Tapered surface P Intermediate position in the axial direction of the raceway groove Q Intermediate position in the axial direction of the bearing 40 Ball bearing 41 Insulating sleeve ( Insulation layer)
42 Ring part 43 Hole disc part 44 Tapered surface (guide part)
45 Refueling hole

Claims (6)

An outer ring having an outer ring raceway groove on an inner peripheral surface, an inner ring having an inner ring raceway groove on an outer peripheral surface, a plurality of balls arranged so as to be able to roll between the both raceway grooves, and rolling the balls into a pocket A ball bearing that is freely lubricated and is oil-lubricated,
Shoulder portions are respectively formed on both axial sides of both raceway grooves of the outer ring and inner ring, and at least one shoulder portion of the outer ring and inner ring on one side in the axial direction faces inward from the axial end portion. The diameter has been expanded, and
A ball bearing characterized in that a spatial volume on one side in the axial direction is smaller than a spatial volume on the other side in the axial direction. The outer peripheral surface of the shoulder portion of the inner ring on one side in the axial direction has a tapered surface formed so as to increase in diameter from the axial end portion toward the inside,
2. The ball bearing according to claim 1, wherein an inner peripheral surface of a shoulder portion of the outer ring on one side in the axial direction has a tapered surface formed so as to increase in diameter from the end portion in the axial direction toward the inside. .   The ball bearing according to claim 1, wherein the both raceway grooves are offset toward the other side in the axial direction with respect to an axial intermediate position of the bearing.   The ball bearing according to claim 1, wherein an annular rim portion of the retainer is disposed on one side in the axial direction.   A plurality of the cages are formed between an annular rim portion, a column portion projecting in the axial direction, and a plurality of columns arranged at predetermined intervals in the circumferential direction on the axial end surface of the rim portion. 5. A crown-shaped cage having a pocket portion that holds a plurality of balls in a circumferential direction so as to be able to roll at substantially equal intervals. 5. Ball bearing.   The ball bearing according to claim 5, wherein the cage is manufactured by a molding die having two or more resin injection gates.

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