JP2012189112A - Ball bearing retainer and ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily reduce torque due to shear resistance of an lubricating oil by a ball.SOLUTION: A ball bearing retainer for which hemispherical pockets 12 which house balls are formed in multiple locations in the circumferential direction on the opposing surfaces 11 of two ring-shaped bodies 10 which oppose one another in the axial direction, and the opposing surfaces 11 are brought into contact and the two ring-shaped bodies 10 are connected by means of connections 18 provided at both circumferential ends of the pockets 12. Recessed grooves 19 for a lubricant are provided on the inner circumferential surface of the pockets 12.

Description

  The present invention relates to a ball bearing cage made of synthetic resin that holds a ball so as to roll freely, and a ball bearing in which the cage is incorporated between an outer ring and an inner ring.

  For example, various ball bearings such as deep groove ball bearings and angular ball bearings are widely used for gear support shafts of transmissions of vehicles having motors.

  This type of ball bearing includes an inner ring having an inner race surface formed on the outer diameter surface, an outer ring disposed on the outer side of the inner ring and having an outer race surface formed on the inner diameter surface, and an inner race surface of the inner ring. A plurality of balls interposed between the outer ring and the outer raceway surface of the outer ring, and a cage that is arranged between the inner ring and the outer ring and holds the balls at equal intervals in the circumferential direction. Is configured. Either the outer ring or the inner ring is attached to a fixed part such as a housing, and the other is attached to a rotating part such as a rotating shaft.

  In particular, drive motors of electric vehicles and hybrid vehicles tend to be rotated at a high speed for the purpose of reducing the size and improving the efficiency, and a rotating portion such as a rotating shaft also rotates at a high speed. As a result, insufficient lubrication, torque (heat generation), deformation of the cage due to centrifugal force, and the like become problems. The cage deformation due to insufficient lubrication or torque (heat generation) can be solved by devising the shape of the cage, and by using a lightweight synthetic resin cage, It is possible to suppress deformation of the cage.

  Various lightweight synthetic resin cages have been proposed for the purpose of suppressing deformation of the cage due to centrifugal force. This type of cage is composed of a main part having an annular shape and a pair of elastic pieces integrally projected in a circumferentially spaced manner on one axial surface of the main part with a space between each other. Some of them have a crown shape that holds a ball so as to roll freely in a pocket recessed between the pair of elastic pieces. In this crown type cage, the ball is held from only one side, so when a large centrifugal force is applied, the ball may drop out of the pocket due to uneven deformation, and may interfere with other parts such as inner and outer rings. There is.

  In order to eliminate such concerns, various types of axial alignment type cages that hold balls from both sides have been proposed (for example, see Patent Document 1). The cage disclosed in Patent Document 1 has a structure in which a pair of annular bodies are coupled to each other in the axial direction, and an annular base portion and a column portion standing upright from the base portion are integrally formed. The ring-shaped bodies are opposed to each other so that one pillar portion is located at an intermediate point between the other pillar portions, and are joined so as to form a pocket for holding a ball between adjacent pillar portions. Is.

JP 2009-115128 A

  In recent years, in ball bearings for automobiles, torque reduction has been demanded from environmental problems such as improved fuel consumption. Of the torque in ball bearings used under oil bath lubrication, the shearing resistance of the lubricating oil by the balls accounts for a large proportion of the torque generated between the cage and the balls. Further, most of the shear resistance is generated when the oil film formed between the inner peripheral surface of the pocket and the outer diameter surface of the ball accommodated in the pocket is sheared.

  By the way, the pocket which covers a ball | bowl, when the inner peripheral surface of a pocket is formed with the single curved surface which follows the outer diameter shape of a ball | bowl like the axial direction alignment type holder | retainer disclosed by patent document 1. The area of the inner peripheral surface of this is increased as compared with the crown type cage. This is because when the lubricating oil tries to pass through a minute gap between the outer diameter surface of the ball and the inner peripheral surface of the pocket, the shearing resistance of the lubricating oil increases, and the shearing resistance increases the bearing torque (heat generation). ) Is one factor that increases.

  Therefore, the present invention has been proposed in view of the above-described problems, and the object of the present invention is to provide a ball bearing cage and ball that can easily reduce torque caused by the shear resistance of lubricating oil by the ball. It is to provide a bearing.

  As a technical means for achieving the above-described object, the present invention forms hemispherical pockets for accommodating balls on the opposing surfaces of two annular members facing in the axial direction at a plurality of locations in the circumferential direction. Is a ball bearing retainer in which two annular bodies are coupled by coupling portions provided at both ends in the circumferential direction of the pocket, and a recess for lubricating oil removal is provided on the inner peripheral surface of the pocket. It is characterized by that. The cross-sectional shape of the recess may be either an arc shape or a square shape, and is arbitrary.

  In the present invention, by providing the recess for lubricating oil removal on the inner peripheral surface of the pocket, the gap between the outer diameter surface of the ball and the inner peripheral surface of the pocket is expanded, Is easier to pass. For this reason, the shear resistance of the lubricating oil by the balls can be kept small, and the torque can be easily reduced.

  The coupling portion in the present invention is such that the outer peripheral side of the circumferential end of one annular body extends in the axial direction to form an outer convex portion, and the inner peripheral surface thereof can be brought into contact with the rolling element. In addition, the inner diameter side is recessed to form an inner diameter side recess, and the inner circumferential surface of the other annular body pocket is extended in the axial direction to form the inner diameter side convex portion. Can be brought into contact with the rolling element, and the outer diameter side is recessed to form an outer diameter side concave portion, and the outer diameter side convex portion is inserted into the outer diameter side concave portion and the inner diameter side convex portion is inserted into the inner diameter side concave portion. Thus, the outer diameter side convex portion and the inner diameter side convex portion are engaged in the axial direction, and the engagement surface of the outer diameter side convex portion and the inner diameter side convex portion is used as the base end of the outer diameter side convex portion and the inner diameter side convex portion. A structure that is inclined with respect to the axial direction so that the tip side is thicker than the side is desirable.

  In this way, by engaging the outer diameter side convex portion and the inner diameter side convex portion in the axial direction, a frictional force is generated along the engagement surface between the outer diameter side convex portion and the inner diameter side convex portion. . Further, the engagement surface between the outer diameter side convex portion and the inner diameter side convex portion is inclined with respect to the axial direction so that the distal end side is thicker than the proximal end side of the outer diameter side convex portion and the inner diameter side convex portion. As a result, the axial component of the reaction force generated in the normal direction of the engagement surface between the outer diameter side convex portion and the inner diameter side convex portion appears. High rotation speed is achieved by a synergistic effect of the frictional force generated along the engagement surface between the outer diameter side convex portion and the inner diameter side convex portion and the axial component of the reaction force generated in the normal direction of the engagement surface. Even when a larger centrifugal force is applied, it is possible to reliably prevent the two annular bodies from separating in the axial direction.

  The coupling part in the present invention preferably has a structure in which the inclination angle of the engagement surface between the outer diameter side convex part and the inner diameter side convex part is 5 ° or more. By setting the inclination angle in this way, it becomes easy to suppress deformation of the engagement surface when a large centrifugal force is applied due to high rotation, and the axial component of the reaction force is reliably applied to the engagement surface. This makes it easy to secure the coupling force between the two annular bodies. When the inclination angle of the engagement surface is smaller than 5 °, it becomes difficult to suppress deformation of the engagement surface when a large centrifugal force is applied due to high rotation, and the axial direction of the reaction force is applied to the engagement surface. It becomes difficult to ensure that the components act.

  The coupling portion in the present invention preferably has a structure in which the inner diameter side convex portion is thicker than the outer diameter side convex portion. In this way, when a large centrifugal force is applied due to high rotation, the inner diameter side convex portion made thicker than the outer diameter side convex portion is larger in mass than the outer diameter side convex portion. A convex part deform | transforms larger than an outer diameter side convex part. Here, the engagement surface of the outer diameter side convex portion and the inner diameter side convex portion is inclined with respect to the axial direction so that the distal end side is thicker than the proximal end side of the outer diameter side convex portion and the inner diameter side convex portion. Therefore, the deformation of the inner diameter side convex portion acts to increase the coupling force on the engagement surface between the outer diameter side convex portion and the inner diameter side convex portion.

  The coupling portion in the present invention has a structure in which an outer diameter side convex portion and an inner diameter side concave portion are formed at one circumferential end portion of the pocket, and an inner diameter side convex portion and an outer diameter side concave portion are formed at the other circumferential end portion. Is desirable. With such a structure, it is possible to make one annular body and the other annular body by using a kind of annular body manufactured by one mold, and the product cost can be reduced.

  In addition, it is effective that the annular body in the present invention is made of a synthetic resin in that the weight of the cage can be reduced. As the synthetic resin constituting the cyclic body, any one selected from a polyamide resin, a polyether ether ketone resin, a polyphenylene sulfide resin, a polyphthalamide resin, or a polyamideimide resin is preferable.

  A ball bearing can be configured by adding an outer ring and an inner ring that rotate relative to each other and a ball interposed between the outer ring and the inner ring to the cage having the above-described configuration.

  According to the present invention, by providing the recess for lubricating oil removal on the inner peripheral surface of the pocket, the gap between the outer diameter surface of the ball and the inner peripheral surface of the pocket is enlarged, and the gap is reduced. Lubricating oil easily passes. Therefore, the shear resistance of the lubricating oil by the balls can be kept small. As a result, it becomes easy to reduce the torque generated between the cage and the balls due to the shear resistance of the lubricating oil by the balls. As a result, it is possible to easily provide a ball bearing for automobiles that is suitable for environmental problems such as fuel efficiency improvement in recent years.

In embodiment of this invention, it is an assembly exploded perspective view which shows the state before couple | bonding two annular bodies. FIG. 2 is an assembled perspective view showing a state after two annular bodies in FIG. 1 are joined together. It is a partial expanded view which shows the two annular bodies before a coupling | bonding. It is a partial expanded view which shows the two annular bodies after a coupling | bonding. In other embodiment of this invention, it is an assembly exploded perspective view which shows the state before couple | bonding two annular bodies. FIG. 6 is an assembled perspective view showing a state after the two annular members of FIG. 5 are joined together. It is a partial expanded view which shows the two annular bodies before a coupling | bonding. It is a partial expanded view which shows the two annular bodies after a coupling | bonding. It is sectional drawing which follows the AA line of FIG. 3, and the EE line of FIG. It is sectional drawing which follows the BB line of FIG. 3, and the FF line of FIG. It is sectional drawing which follows the CC line of FIG. 4, and the GG line of FIG. It is sectional drawing which follows the DD line of FIG. 4, and the HH line of FIG. It is sectional drawing which shows the ball bearing incorporating the cage | basket of this invention.

  Embodiments of a ball bearing retainer and a ball bearing according to the present invention will be described in detail below. The ball bearing of this embodiment is particularly suitable for a sealed ball bearing as a high rotation bearing for automobiles used under oil bath lubrication in an electric vehicle or a hybrid vehicle, but is not a sealed type. Applicable to ball bearings.

  As shown in FIG. 13, the ball bearing 1 of this embodiment is disposed on the outer side of the inner ring 2 having the inner race surface 2 a formed on the outer diameter surface and on the outer side of the inner ring 2, and on the outer race surface 3 a on the inner diameter surface. Between the inner ring 2 and the outer ring 3, between the inner ring 2 and the outer ring 3, between the inner ring 2 and the outer ring 3, the inner ring 2 and the outer ring 3. A cage 5 that holds the balls 4 at equal intervals in the circumferential direction, and a seal portion 7 that is arranged in an annular space 6 formed between the inner ring 2 and the outer ring 3 and has a sealing lip made of an elastic member, The main part is composed of.

  In this embodiment, the outer ring 3 is mounted on a fixed part such as a housing, and the inner ring 2 is mounted on a rotating part such as a rotating shaft. The seal portion 7 is composed of a seal member 8b made of an elastic member such as rubber that is integrally vulcanized and bonded to the core metal 8a. The seal member 8b is an inner diameter end portion of the outer ring 3 whose base end portion is a fixed side. And has a seal lip 8c in contact with the outer diameter end of the inner ring 2 at the tip. Although the inner ring rotation type is illustrated in this embodiment, the present invention can also be applied to an outer ring rotation type in which the inner ring 2 is mounted on a fixed part such as a housing and the outer ring 3 is mounted on a rotating part such as a rotation shaft. .

  The ball bearing 1 includes a lightweight synthetic resin cage 5 for the purpose of suppressing deformation of the cage 5 due to centrifugal force under high speed rotation. As shown in FIGS. 1 and 2, this type of cage 5 has a hemispherical shape in which balls 4 (see FIG. 13) are rotatably accommodated on opposing surfaces 11 of two annular members 10 facing in the axial direction. The pockets 12 are formed at a plurality of locations in the circumferential direction, the opposing surfaces 11 of the annular body 10 are brought into contact with each other, and the two annular bodies 10 are coupled by the coupling portions 18 provided at both circumferential ends of the pocket 12. It has a symmetrical shape. The inner peripheral surface of the pocket 12 in the annular body 10 has a concave spherical shape with a single radius of curvature.

  1 to 4 show an embodiment of the present invention. FIGS. 1 and 3 show a state before two annular bodies 10 are joined together, and FIGS. 2 and 4 show two annular bodies 10 joined together. The state after having been made to show is shown. As shown in the figure, in this embodiment, a recess 19 for lubricating oil removal having an arcuate cross section is provided on the inner peripheral surface of the pocket 12. The concave portions 19 are formed in a concave groove shape extending in the radial direction at two locations on the inner peripheral surface of the pocket 12 of each annular body 10.

  5 to 8 show other embodiments of the present invention, and FIGS. 5 and 7 show a state before two annular bodies 10 are joined, and FIGS. 6 and 8 show two annular bodies 10 joined together. The state after having been made to show is shown. As shown in the figure, in this embodiment, a recess 20 for lubricating oil removal having a square cross section is provided on the inner peripheral surface of the pocket 12. The concave portion 20 is formed in a concave groove shape extending in the radial direction at two locations on the inner peripheral surface of the pocket 12 of each annular body 10.

  In the cage 5 in these embodiments, the recesses 19 and 20 for lubricating oil removal are provided on the inner peripheral surface of the pocket 12, so that a gap between the outer diameter surface of the ball 4 and the inner peripheral surface of the pocket 12 is provided. As a result, the lubricating oil easily passes through the gap. Therefore, the shear resistance of the lubricating oil by the balls 4 can be kept small, and the torque can be easily reduced.

  Here, the recesses 19 and 20 have a concave groove shape formed on the inner peripheral surface of the pocket 12 so as to pass through between the radial outer diameter side and the radial inner diameter side. And the lubricating oil more easily pass through the gap that is enlarged between the inner peripheral surface of the pocket 12. Moreover, in this embodiment, although the recessed parts 19 and 20 are provided in two places of the internal peripheral surface of the pocket 12 of each cyclic | annular body 10, about the position and number of the recessed parts 19 and 20, it is arbitrary.

  The cage 5 of the above embodiment includes the following coupling structure as means for coupling the two annular bodies 10.

  As shown in FIGS. 1, 3, 5, and 7, each of the two annular bodies 10 is formed so that the outer diameter side of one circumferential end portion of the pocket 12 extends in the axial direction to the outer diameter side. The convex portion 13 is formed and the inner diameter side concave portion 14 is formed by denting the inner diameter side, and the inner diameter side convex portion 15 is formed by extending the inner diameter side of the other circumferential end of the pocket 12 in the axial direction. In addition, the outer diameter side recess 16 is formed by denting the outer diameter side.

  As described above, the two annular bodies 10 each form the outer diameter side convex portion 13 and the inner diameter side concave portion 14 at one circumferential end portion of the pocket 12, and the inner circumferential side convex portion at the other circumferential end portion. By adopting the structure in which the portion 15 and the outer diameter side concave portion 16 are formed, one annular body 10 and the other annular body 10 can be formed by using a kind of annular body 10 manufactured by one mold. The product cost can be reduced.

  In this structure, the outer diameter side convex portion 13 of one annular body 10 is inserted into the outer diameter side concave portion 16 of the other annular body 10, and the inner diameter side convex portion 15 of one annular body 10 is inserted into the other annular body 10. By inserting into the inner diameter side concave portion 14, the outer diameter side convex portion 13 and the inner diameter side convex portion 15 are engaged in the axial direction. Further, the engagement surfaces 13a, 15a of the outer diameter side convex portion 13 and the inner diameter side convex portion 15 are thicker at the distal end side than the proximal end sides of the outer diameter side convex portion 13 and the inner diameter side convex portion 15. It is inclined with respect to the axial direction (see FIGS. 9 and 10).

  As shown in FIGS. 2, 4, 6, and 8, the opposing surfaces 11 of the two annular bodies 10 are brought into contact with each other, and the outer diameter side convex portion 13 and the inner diameter side convex portion 15 are fixed to each other with a predetermined fastening allowance. Thus, by engaging in the axial direction, a frictional force is generated along the engagement surfaces 13a and 15a of the outer diameter side convex portion 13 and the inner diameter side convex portion 15. Further, the engagement surfaces 13a, 15a of the outer diameter side convex portion 13 and the inner diameter side convex portion 15 are thicker at the distal end side than the proximal end sides of the outer diameter side convex portion 13 and the inner diameter side convex portion 15. By tilting with respect to the axial direction, an axial component of the reaction force generated in the normal direction of the engagement surfaces 13a, 15a of the outer diameter side convex portion 13 and the inner diameter side convex portion 15 appears.

  Axial component of the frictional force generated along the engagement surfaces 13a and 15a between the outer diameter side convex portion 13 and the inner diameter side convex portion 15 and the reaction force generated in the normal direction of the engagement surfaces 13a and 15a. As a result, the two annular bodies 10 can be reliably prevented from separating in the axial direction even when a large centrifugal force is applied due to high rotation.

  Thus, by providing the joint part 18 which consists of the outer diameter side convex part 13, the inner diameter side concave part 14, the inner diameter side convex part 15, and the outer diameter side concave part 16 at both ends in the circumferential direction of the pocket 12 of the annular body 10. When a large centrifugal force is applied due to high rotation, even if one annular body 10 and the other annular body 10 are spaced apart from each other in the axial direction and the pocket 12 is opened, the above-described coupling portion 18 causes the ball 4 to be opened. Can be easily maintained in the pocket 12.

  In the coupling structure of this embodiment, the inclination angle θ (see FIGS. 9 and 10) of the engagement surfaces 13a and 15a between the outer diameter side convex portion 13 and the inner diameter side convex portion 15 needs to be 5 ° or more. By setting the inclination angle θ in this way, it becomes easy to suppress deformation of the engagement surfaces 13a and 15a when a large centrifugal force is applied due to high rotation, and a reaction force is applied to the engagement surfaces 13a and 15a. An axial component can be made to act reliably, and it becomes easy to ensure the coupling force of the two annular bodies 10. If the inclination angle θ of the engagement surfaces 13a and 15a is smaller than 5 °, it becomes difficult to suppress deformation of the engagement surfaces 13a and 15a when a large centrifugal force is applied due to high rotation. It becomes difficult to reliably apply the axial component of the reaction force to the surfaces 13a and 15a.

Moreover, in this coupling structure, as shown in FIGS. 11 and 12, the inner diameter side convex portion 15 is thicker than the outer diameter side convex portion 13 (t _IN > t _OUT ). By making the inner diameter side convex portion 15 thicker than the outer diameter side convex portion 13 in this way, the inner diameter side made thicker than the outer diameter side convex portion 13 when a large centrifugal force is applied due to high rotation. Since the mass of the convex portion 15 is larger than that of the outer diameter side convex portion 13, the inner diameter side convex portion 15 is deformed larger than the outer diameter side convex portion 13. Here, the engagement surfaces 13a and 15a of the outer diameter side convex portion 13 and the inner diameter side convex portion 15 are thicker on the distal end side than the proximal end sides of the outer diameter side convex portion 13 and the inner diameter side convex portion 15. Therefore, the deformation of the inner diameter side convex portion 15 increases the coupling force between the outer diameter side convex portion 13 and the inner diameter side convex portion 15 at the engagement surfaces 13a, 15a. Works.

  The annular body 10 described above is made of a synthetic resin in order to reduce the weight of the cage 5. Synthetic resins constituting the annular body 10 include polyamide resins (PA46, PA66, PA9T, PA11, PA6, etc.), polyetheretherketone resins (PEEK), polyphenylene sulfide in consideration of cost and oil resistance. Any one selected from resin (PPS), polyphthalamide resin (PPA), and polyamideimide resin (PAI) is preferable.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 1 Ball bearing 2 Inner ring 3 Outer ring 4 Ball 5 Cage 10 Ring body 11 Opposite surface 12 Pocket 13 Outer diameter side convex part 13a Engagement surface 14 Inner diameter side concave part 15 Inner diameter side convex part 15a Engagement surface 16 Outer diameter side concave part 18 Coupling Part 19, 20 concave part θ inclination angle

Claims (10)

  Hemispherical pockets for receiving balls are formed in a plurality of locations in the circumferential direction on opposing surfaces of two annular members facing in the axial direction, and the opposing surfaces are abutted to be provided at both ends in the circumferential direction of the pockets. A ball bearing retainer in which two annular bodies are coupled by a coupling portion, wherein a concave for oil removal is provided on the inner peripheral surface of the pocket.   The ball bearing retainer according to claim 1, wherein the concave portion has an arc shape in cross section.   The ball bearing retainer according to claim 1, wherein the recess has a square cross-sectional shape.   The coupling portion extends the outer diameter side of the circumferential end of the pocket of one annular body in the axial direction to form a convex portion on the outer diameter side so that the inner circumferential surface can come into contact with the ball. The inner diameter side is recessed to form an inner diameter side concave portion, and the inner circumferential surface of the other annular body pocket is extended in the axial direction to form an inner diameter side convex portion. The outer diameter side recess is formed by allowing the ball to come into contact with the outer diameter side, and the outer diameter side convex portion is inserted into the outer diameter side concave portion and the inner diameter side convex portion is inserted into the inner diameter side concave portion. Thus, the outer diameter side convex portion and the inner diameter side convex portion are engaged with each other in the axial direction, and the engagement surface between the outer diameter side convex portion and the inner diameter side convex portion is formed between the outer diameter side convex portion and the inner diameter side convex portion. The ball bearing retainer according to any one of claims 1 to 3, wherein the ball bearing retainer is inclined with respect to the axial direction so that the distal end side is thicker than the proximal end side.   The ball bearing retainer according to claim 4, wherein the coupling portion has an inclination angle of an engagement surface between the outer diameter side convex portion and the inner diameter side convex portion of 5 ° or more.   The ball bearing retainer according to claim 4 or 5, wherein the coupling portion is formed such that the inner diameter side convex portion is thicker than the outer diameter side convex portion.   The coupling portion has an outer diameter side convex portion and an inner diameter side concave portion formed at one circumferential end portion of the pocket, and an inner diameter side convex portion and an outer diameter side concave portion formed at the other circumferential end portion. The ball bearing retainer according to any one of 4 to 6.   The ball bearing retainer according to any one of claims 1 to 7, wherein the annular body is made of a synthetic resin.   The ball bearing retainer according to claim 8, wherein the synthetic resin is any one selected from a polyamide resin, a polyether ether ketone resin, a polyphenylene sulfide resin, a polyphthalamide resin, or a polyamideimide resin.   A ball bearing comprising the cage according to claim 1, an outer ring and an inner ring that rotate relative to each other, and a ball interposed between the outer ring and the inner ring.

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