JP2019173790A - Deep groove ball bearing - Google Patents

Abstract

To provide a deep groove ball bearing capable of improving assembling characteristic of a cage into a space between an outer ring and an inner ring while preventing an expansion of a claw at the cage under an application of high speed operation.SOLUTION: A deep groove ball bearing 10 used under environment of dmn value of a product between a pitch circle diameter dm(mm) and a revolution speed n(min) more than 70 thousands is set such that an outer diameter of a cage 14 is larger than a pitch circle diameter of a ball, a size of a clearance in a radial direction between an inner peripheral surface of the cage 14 and an inner peripheral surface of an outer ring is smaller than a size of a clearance in a radial direction between an outer peripheral surface of the cage 14 and an inner peripheral surface of the outer ring 12, an inlet side end part of the outer peripheral surface of the inner ring 11 when the cage 14 is assembled is formed with an inner ring 11 tapered surface 17 of which diameter is reduced as an outer diameter of the inner ring 11 is faced outside in an axial direction, and an extremity end side end part at the inner peripheral surface of the cage 14 is formed with a cage tapered surface 16 of which diameter is expanded to the outer ring 12 side as the inner diameter of the cage 14 is faced to the extremity end side of the cage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a deep groove ball bearing that improves the ease of assembling a cage while preventing deformation under a high-speed use environment.

  In recent years, multistage transmissions have been promoted for the purpose of reducing the fuel consumption of automobiles. With this multistage operation, the planetary gear mechanism 1 shown in FIG. 3 may be used. The planetary gear mechanism 1 includes a sun gear 2 disposed on the rotational axis, a ring gear 3 disposed on the outermost periphery, and a planetary gear 4 interposed between the sun gear 2 and the ring gear 3. The ring gear 3 is held in a housing 5 such as a gear box by a large-diameter deep groove ball bearing 30.

The deep groove ball bearing 30 has a resin crown-shaped cage (hereinafter referred to as a cage) for holding a plurality of balls at equal intervals in the circumferential direction. The deep groove ball bearing 30 may be used in a high-speed use environment where the dmn value, which is the product of the pitch circle diameter dm (mm) and the rotational speed n (min ⁻¹ ), is 700,000 or more. At this time, a large centrifugal force acts on the cage, and the centrifugal force may cause a phenomenon in which the claw portion opens radially outward. If the claw portion opens radially outward, the claw portion and the ball may interfere with each other.

  In order to prevent the opening of the claw portion of the cage under a high-speed use environment, for example, in Patent Document 1 below, a protrusion is formed on the outer peripheral surface of the resin crown-shaped cage. By reinforcing the cage with this protrusion, the rigidity is increased and the opening of the claw portion to the outer diameter side during high-speed rotation of the bearing is prevented as much as possible.

JP 2000-170772 A

  In the ball bearing according to Patent Document 1, since the protrusion is formed on the outer peripheral surface of the cage, the gap between the outer peripheral surface and the inner peripheral surface of the outer ring is reduced. For this reason, even if it can suppress a deformation | transformation of the nail | claw part of a holder | retainer, interference with the outer peripheral surface of the nail | claw part of a holder | retainer and the inner peripheral surface of an outer ring | wheel tends to arise, and there exists a possibility of causing damage to a holder | retainer.

  In addition, during high-speed rotation, the bearing tends to generate a high temperature due to heat generation. At this time, the linear expansion coefficient of the resin constituting the cage is larger than the linear thermal expansion coefficient of the iron constituting the outer ring. There is a possibility that the radial gap between the surface and the inner peripheral surface of the outer ring becomes small, and the two interfere with each other to cause damage to the cage.

  Moreover, in recent years, bearings have become thinner due to demands for space saving, and the initial clearance between the outer diameter of the cage and the inner diameter of the outer ring when the bearing is stopped (at room temperature) has become smaller. And the outer ring are likely to interfere with each other.

  In order to avoid interference between the cage and the outer ring, as shown in FIG. 6, an inner ring 21, an outer ring 22 provided on the radially outer side of the inner ring 21, and an inner ring 21 and an outer ring 22 are provided. In the deep groove ball bearing 20 having a plurality of balls 23 and a rolling element guide type cage 24 that holds the plurality of balls 23 at predetermined intervals in the circumferential direction, the cage 24 is used as a general rolling element guide. Compared to the cage of the mold, it can be considered to have a shape with a reduced inner diameter without changing the outer diameter. Thus, by reducing the inner diameter of the cage 24, the thickness in the radial direction of the cage 24 can be increased to increase the rigidity, and the deep groove ball bearing 20 is caused by centrifugal force during high-speed rotation. It can be expected that the deformation of the claw portion 25 is prevented.

  However, when the inner diameter of the cage 24 is reduced, there is a problem that the assemblability of the cage 24 is lowered. That is, since the radial clearance between the inner circumferential surface of the cage 24 and the outer circumferential surface of the inner ring 21 is small, when the cage 24 is assembled between the inner ring 21 and the outer ring 22 from the axial direction, FIG. As shown, the axial centers of the inner ring 21 and the cage 24 must be matched with high accuracy. If there is a misalignment between the two, as shown in FIG. 8, the tip of the claw portion 25 of the retainer 24 comes into contact with the end surface of the inner ring 21, causing a problem that the retainer 24 cannot be assembled smoothly.

  Accordingly, an object of the present invention is to improve the assembling property of the cage between the inner and outer rings while preventing the claw portion of the cage from spreading in a high-speed use environment.

In order to solve the above-described problems, in the present invention, an inner ring, an outer ring provided on the radially outer side of the inner ring, and a plurality of balls provided to be interposed between the inner ring and the outer ring, A dmn value that is a product of a pitch circle diameter dm (mm) and a rotational speed n (min ⁻¹ ), and a cage that is incorporated between the inner ring and the outer ring and holds the plurality of balls. Is a deep groove ball bearing used in a usage environment of 700,000 or more, the outer diameter of the cage is larger than the pitch circle diameter of the balls, and the inner circumferential surface of the cage and the outer circumferential surface of the inner ring When the size of the gap in the radial direction is smaller than the size of the gap in the radial direction between the outer circumferential surface of the cage and the inner circumferential surface of the outer ring, and the cage is incorporated in the outer circumferential surface of the inner ring The outer diameter of the inner ring shrinks toward the outer side in the axial direction. An inner ring taper surface is formed, and a cage taper surface that expands toward the outer ring side as the inner diameter of the cage moves toward the tip side of the cage at the tip side end portion of the inner circumferential surface of the cage A deep groove ball bearing characterized in that is formed.

  Thus, the size of the radial gap between the inner peripheral surface of the cage and the outer peripheral surface of the inner ring is smaller than the size of the radial gap between the outer peripheral surface of the cage and the inner peripheral surface of the outer ring. In addition, by substantially reducing the inner diameter of the cage, the thickness in the radial direction of the cage can be increased and the rigidity can be increased. At the time of high-speed rotation of the bearing, the claw portion caused by centrifugal force Can be prevented from being deformed.

  In addition, by forming the cage taper surface on the cage and the inner ring taper surface on the inner ring, when the cage is assembled from the axial direction between the inner ring and the outer ring, there is a misalignment between the two. Also, the center misalignment is corrected by sliding the cage taper surface and the inner ring taper surface in contact with each other. Thereby, the tolerance | permissible_quantity with respect to the initial amount of misalignment becomes large, and a holder | retainer can be smoothly integrated between an inner and outer ring | wheel.

  In the said structure, it is preferable that the taper angle of the said retainer taper surface with respect to an axial direction is 5 to 45 degree | times. Moreover, it is preferable that the taper angle of the inner ring tapered surface with respect to the axial direction is not less than 5 degrees and not more than 45 degrees. Thus, by defining the range of both taper angles, the cage taper surface slides smoothly with respect to the inner ring taper surface, and the misalignment between the inner ring and the cage can be corrected more quickly.

  In each configuration, the taper angle of the cage taper surface with respect to the axial direction and the taper angle of the inner ring taper surface with respect to the axial direction are the same, or the taper angle of the cage taper surface with respect to the axial direction and the axial direction. The difference from the taper angle of the inner ring tapered surface is preferably 3 degrees or less. Thus, by making the taper angles of both tapered surfaces the same or making the difference between the two taper angles 3 degrees or less, the cage taper surface slides smoothly with respect to the inner ring taper surface, and the inner ring and the cage core The deviation can be corrected more rapidly.

  In each said structure, it is preferable that the axial direction dimension of the said holder shall be 1.2 to 2.0 times the diameter of the said ball | bowl. Thereby, the rigidity of the cage can be improved by extending the back surface of the cage outward in the axial direction, and deformation of the cage during high-speed rotation can be further suppressed.

  In the present invention, it is possible to improve the assembling property of the cage between the inner and outer rings while preventing the claw portion of the cage from spreading in a high-speed use environment.

Sectional drawing which shows one Embodiment of the deep groove ball bearing which concerns on this invention The perspective view which shows the crown-shaped cage employ | adopted as the deep groove ball bearing shown in FIG. Sectional drawing which shows the example of application to the planetary gear mechanism of the deep groove ball bearing shown in FIG. Sectional drawing which shows the assembly process (before assembly) of the cage to the deep groove ball bearing shown in FIG. Sectional drawing which shows the assembly process (during assembly) of the cage to the deep groove ball bearing shown in FIG. Sectional drawing which shows an example of the deep groove ball bearing which concerns on a prior art Sectional drawing which shows the assembly process (before assembly) of the cage to the deep groove ball bearing shown in FIG. Sectional drawing which shows the assembly process (during assembly) of the cage to the deep groove ball bearing shown in FIG.

An embodiment of a deep groove ball bearing 10 according to the present invention is shown in FIG. The deep groove ball bearing includes an inner ring 11, an outer ring 12 provided on the radially outer side of the inner ring 11, a plurality of balls 13 provided between the inner ring 11 and the outer ring 12, and a plurality of balls 13. And a retainer 14 that retains at predetermined intervals in the circumferential direction. The deep groove ball bearing 10 is assumed to be used in a high-speed use environment in which the dmn value, which is the product of the pitch circle diameter dm (mm) and the rotation speed n (min ⁻¹ ), is 700,000 or more.

  Here, a direction parallel to the rotation axis of the deep groove ball bearing 10 is referred to as an axial direction, a direction orthogonal to the rotation axis is referred to as a radial direction, and a direction along an arc centered on the rotation axis is referred to as a circumferential direction.

  The retainer 14 is a rolling element guide type crown retainer guided by the balls 13. The outer diameter of the cage 14 is larger than the pitch circle diameter (PCD) of the balls 13. The axial dimension of the cage 14 is 1.2 to 2.0 times the diameter of the ball 13. The material of the cage 14 is a polyamide resin. As shown in FIG. 2, the retainer 14 is formed with pockets 18 for holding the balls 13 at predetermined intervals in the circumferential direction. The pocket 18 penetrates in the radial direction of the cage 14 and opens to one side in the cage axial direction. A pair of claw portions 15 are formed on both sides in the circumferential direction of the opening of each pocket 18. The claw portion 15 extends in the axial direction from the annular portion 19 arranged on one side in the axial direction to the side approaching the ball 13.

  The cage 14 has a shape in which the inner diameter is reduced without changing the outer diameter, compared to a general rolling element guide type cage. As a result, the size g1 of the radial gap between the inner peripheral surface of the cage 14 and the outer peripheral surface of the inner ring 11 is equal to the radial gap between the outer peripheral surface of the cage 14 and the inner peripheral surface of the outer ring 12. It is smaller than the size g2. Thus, by reducing the inner diameter of the cage 14, the thickness in the radial direction of the cage 14 can be increased and the rigidity can be increased, and due to the centrifugal force during the high-speed rotation of the deep groove ball bearing 10. It is possible to prevent the claw portion 15 from being deformed.

  As shown in FIG. 1 and FIG. 2, a cage taper surface that expands toward the outer ring 12 as the inner diameter of the cage 14 moves toward the cage tip side at the tip side end portion of the inner circumferential surface of the cage 14. 16 is formed. Specifically, the cage taper surface 16 is provided on the tip side end portion of the inner peripheral surface of the claw portion 15. The taper angle of the cage taper surface 16 with respect to the axial direction is α. In this embodiment, the taper angle α is 25 degrees, but the taper angle α is appropriately changed within a range of 5 degrees to 45 degrees, preferably within a range of 20 degrees to 30 degrees. can do.

  An inner ring tapered surface 17 whose diameter decreases as the outer diameter of the inner ring 11 moves outward in the axial direction (side away from the ball 13) is formed at the inlet side end of the inner ring 11 when the retainer 14 is incorporated. Has been. The axial length of the inner ring tapered surface 17 is longer than the axial length of the cage tapered surface 16. The back surface 14 a of the retainer 14 is located on the axially outer side from the axial center of the inner ring tapered surface 17. The taper angle of the inner ring tapered surface 17 with respect to the axial direction is β. The taper angle β according to this embodiment is 25 degrees, but the taper angle β is appropriately within a range of 5 degrees to 45 degrees, preferably within a range of 20 degrees to 30 degrees. Can be changed.

  The taper angle α of the cage taper surface 16 and the taper angle β of the inner ring taper surface 17 are preferably substantially the same. In this way, the cage taper surface 16 slides smoothly with respect to the inner ring taper surface 17, and the misalignment between the inner ring 11 and the cage 14 can be corrected more quickly. Here, “same” means not only the case where both taper angles α and β are exactly the same, but also the difference (α−β) between both taper angles α and β is, for example, within a range of ± 1 degree, preferably Including the case of within the range of ± 3 degrees, more preferably within the range of ± 5 degrees.

  The deep groove ball bearing 10 according to the present invention can be applied to, for example, the planetary gear mechanism 1 shown in FIG. The planetary gear mechanism 1 includes a sun gear 2 disposed on the rotational axis, a ring gear 3 disposed on the outermost periphery, and a planetary gear 4 interposed between the sun gear 2 and the ring gear 3. The ring gear 3 is held in a housing 5 such as a gear box by a large diameter deep groove ball bearing 10.

  The deep groove ball bearing 10 that holds the ring gear 3 rotates at a high speed as the diameter increases. In this way, even when used in a high-speed environment, by configuring the deep groove ball bearing 10 as described above, the deformation of the claw portion 15 due to the centrifugal force at the time of high-speed rotation of the bearing is suppressed. Damage to the cage 14 due to deformation can be prevented.

  The cage 14 according to this embodiment has a reduced inner diameter, and since the radial gap between the inner circumferential surface of the cage 14 and the outer circumferential surface of the inner ring 11 is small, it is between the inner ring 11 and the outer ring 12. When the cage 14 is assembled in the axial direction, as shown in FIG. 4, it is originally necessary to align the axial centers of the inner ring 11 and the cage 14 with high accuracy.

  In the deep groove ball bearing 10 according to this embodiment, the cage taper surface 16 is formed on the cage 14 and the inner ring taper surface 17 is formed on the inner ring 11, so that as shown in FIG. When the cage 14 is assembled from the axial direction between the two, even if there is a misalignment between the two, the misalignment is corrected by sliding the retainer tapered surface 16 and the inner ring tapered surface 17 in contact with each other. Is done. Thereby, the tolerance | permissible_quantity with respect to the initial amount of misalignment becomes large, and the holder | retainer 14 can be smoothly integrated between the inner and outer rings 11 and 12.

  The deep groove ball bearing 10 shown in the above embodiment is merely an example, and it is possible to incorporate the cage 14 between the inner and outer rings 11 and 12 while preventing the claw portion 15 of the cage 14 from expanding in a high-speed use environment. As long as the problem of the present invention of improving can be solved, it is allowed to appropriately change the shape, number, arrangement, material, etc. of each member.

  For example, in the above embodiment, a polyamide resin is used as the material of the cage 14, but as the material, polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS) resin, thermoplastic polyimide resin, polyamideimide resin A resin such as a polyamide resin such as nylon 66 resin or nylon 46 resin can also be used.

  Further, in addition to the above configuration, the axial dimension of the cage 14 is 1.2 to 2.0 times the diameter of the ball 13, so that the back surface 14a of the cage 14 is extended outward in the axial direction. The rigidity of the cage 14 is further improved. Thereby, the deformation | transformation of the holder | retainer 14 at the time of high speed rotation can further be suppressed.

DESCRIPTION OF SYMBOLS 10 Deep groove ball bearing 11 Inner ring 12 Outer ring 13 Ball 14 Cage 15 Claw part 16 Cage taper surface 17 Inner ring taper surface α Tapered angle β (of the taper surface of the cage) Taper angle (of the inner ring taper surface)

Claims (6)

An inner ring, an outer ring provided on the radially outer side of the inner ring, a plurality of balls provided between the inner ring and the outer ring, and the inner ring and the outer ring, A deep groove ball that is used in a usage environment having a dmn value that is a product of a pitch circle diameter dm (mm) and a rotation speed n (min ⁻¹ ) of 700,000 or more. In bearings,
The outer diameter of the cage is larger than the pitch circle diameter of the balls,
The size of the radial gap between the inner circumferential surface of the cage and the outer circumferential surface of the inner ring is smaller than the size of the radial gap between the outer circumferential surface of the cage and the inner circumferential surface of the outer ring. ,
An inner ring taper surface that is reduced in diameter as the outer diameter of the inner ring moves outward in the axial direction is formed at the inlet side end portion when the retainer is incorporated in the outer peripheral surface of the inner ring,
Of the inner peripheral surface of the retainer, a distal end side end portion is formed with a retainer taper surface that increases in diameter toward the outer ring as the inner diameter of the retainer moves toward the retainer distal end side. Deep groove ball bearing.   The deep groove ball bearing according to claim 1, wherein a taper angle of the cage taper surface with respect to an axial direction is not less than 5 degrees and not more than 45 degrees.   The deep groove ball bearing according to claim 2, wherein a taper angle of the inner ring taper surface with respect to the axial direction is not less than 5 degrees and not more than 45 degrees.   The deep groove ball bearing according to claim 3, wherein a taper angle of the cage tapered surface with respect to the axial direction is the same as a taper angle of the inner ring tapered surface with respect to the axial direction.   The deep groove ball bearing according to claim 3, wherein a difference between a taper angle of the cage taper surface with respect to the axial direction and a taper angle of the inner ring taper surface with respect to the axial direction is 3 degrees or less.   The deep groove ball bearing according to any one of claims 1 to 5, wherein an axial dimension of the cage is 1.2 to 2.0 times a diameter of the ball.

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