JP2007292195A - Deep groove ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deep groove ball bearing provided with a steel retainer reducing rotational torque of the bearing. <P>SOLUTION: The deep groove ball bearing is provided with an outer ring 2 formed with a circular outer side rolling face 2a on an inner circumference, an inner ring 3 formed with a circular inner side rolling face 3a on an outer circumference, and a plurality of balls housed so as to freely roll between both rolling faces via the retainer 5. The retainer 5 is formed from a steel plate by press working, it is composed of two annular retaining plates 7 applied with diamond-like carbon treatment on surfaces, and ball retaining parts 8 rectangularly swelling in plural portions at equal intervals in a circumferential direction of the annular retaining plates 7. Since the ball retaining parts 8 face each other at an opening side to form polygonal pockets 9, there is point contact between inner circumferential faces of the pocket 9 and the balls 4, a contact width S can be minimized, slide resistance between the balls 4 and the retainer 5 is suppressed, and the rotational torque of the bearing can be reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a deep groove ball bearing that supports a rotating member such as a gear, and more particularly to a deep groove ball bearing provided with a steel plate cage that reduces the rotational torque of the bearing.

  Conventionally, a deep groove ball bearing is generally used as a rolling bearing for supporting rotating members such as motor shafts and gears of automobile transmissions in order to have a small rotational torque and exhibit desired durability against misalignment among rolling bearings. Frequently used. For this deep groove ball bearing, a steel plate cage that is easy to assemble and low in cost is conventionally used. 3 and 4 are typical examples of such cages.

  The cage 50 is formed by pressing a steel plate, and a ball 52 is sandwiched between two annular holding plates 51 and 51 so as to be able to rotate. As shown in FIG. 4A, the two annular holding plates 51 are each formed with a ball holding portion 53 that swells in a hemispherical shape at a plurality of positions at equal intervals in the circumferential direction. In addition, these two annular holding plates 51 face each ball holding portion 53 on the opening side, hold the balls 52 in the pockets 54 formed thereby, and between the ball holding portions 53. It is fixed with rivets 55.

  In this corrugated cage 50, each ball holding portion 53 of the annular holding plate 51 has a distance from the center C of the opening surface of the ball holding portion 53 that is slightly longer than the radius r of the ball 52 at the bottom. However, it is formed so that this distance becomes longer as it becomes a peripheral part. In addition, the radius of curvature of the inner peripheral surface is set to be substantially the same as or slightly larger than the radius r of the ball 52 at the bottom of the ball holding portion 53, and the radius of curvature (r + α) becomes larger toward the peripheral portion. Accordingly, since the distance from the center C of the opening surface is increased at the peripheral edge portion of the inner peripheral surface of the ball holding portion 53, the clearance with the ball 52 is increased.

Further, at the bottom of the inner peripheral surface of the ball holding portion 53, the curvature radius is substantially along the outer peripheral surface of the ball 52, so that the ball 52 can be reliably held at the center of the pocket 54. For this reason, there is no fear that the ball 52 contacts the edge of the joint of the ball holding portions 53, 53 constituting the pocket 54, and the ball 52 is formed at the bottom of the ball holding portions 53 on both sides constituting the pocket 54. Since it rotates around the axis line connecting them, the portion with the smallest peripheral speed of the ball 52 is held only by the bottom portion of the ball holding portion 53, thereby reducing the traction force.
JP 2001-241449 A

  However, in such a conventional corrugated cage 50, since the pocket 54 is formed by the ball holding portion 53 that swells in a hemispherical shape, the ball 52 rotates on the R surface of the pocket 54 while slipping. is doing. Therefore, as shown in FIG. 4B, since the ball 52 is in sliding contact with a certain contact width (contact area) S, a sliding resistance is generated between the ball 52 and the cage 50, and the rotational torque of the bearing is reduced. There were limits. In recent years, for example, transmission bearings have been required to reduce torque in order to improve vehicle fuel efficiency. However, it has been a challenge to reduce the rotational torque of such bearings.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a deep groove ball bearing provided with a steel plate cage that reduces the rotational torque of the bearing.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer ring having an arcuate outer rolling surface formed on the inner periphery, and an arcuate inner surface facing the outer rolling surface on the outer periphery. In a deep groove ball bearing comprising an inner ring formed with a rolling surface and a plurality of balls accommodated between the rolling surfaces via a cage, the cage is pressed from a steel plate by pressing. It is composed of two formed annular holding plates, and ball holding portions bulging in a rectangular shape are formed at a plurality of equally spaced locations in the circumferential direction of the annular holding plates, and these ball holding portions are open side A polygonal pocket is formed by facing each other.

  In this way, in the deep groove ball bearing provided with the steel plate cage, the cage is composed of two annular holding plates formed by pressing from the steel plate, and the annular holding plates are equally spaced in the circumferential direction. A ball holding portion that swells in a rectangular shape is formed at a plurality of locations, and these ball holding portions face each other on the opening side to form a polygonal pocket, so that the inner peripheral surface of the pocket is in point contact with the ball Thus, the contact width can be reduced as much as possible, the slip resistance between the ball and the cage can be suppressed, and the rotational torque of the bearing can be reduced.

  Preferably, if the surface of the cage is subjected to diamond-like carbon treatment as in the invention described in claim 2, the sliding friction between the ball and the cage can be remarkably suppressed. Rotational torque can be reduced.

  In addition, if the ball is made of ceramic as in the third aspect of the invention, torque loss caused by the deformation of the ball on the rolling surfaces of the inner ring and the outer ring can be reduced.

  Further, if the deep groove ball bearing is for an automobile transmission as in the fourth aspect of the invention, an improvement in fuel efficiency can be expected by reducing the rotational torque of the bearing, and minute wear powder is mixed in the lubricating oil. Even under such conditions, wear can be suppressed and sufficient durability against wear powder biting can be exhibited.

  The deep groove ball bearing according to the present invention includes an outer ring in which an arc-shaped outer rolling surface is formed on the inner periphery, and an inner ring in which an arc-shaped inner rolling surface facing the outer rolling surface is formed on the outer periphery, In a deep groove ball bearing comprising a plurality of balls that are slidably accommodated between both rolling surfaces via a cage, the cage is formed of two annular holding plates formed by pressing from a steel plate. Constructed, a ball holding portion that bulges in a rectangular shape is formed at a plurality of equally spaced locations in the circumferential direction of the annular holding plate, and these ball holding portions are confronted on the opening side to form a polygonal pocket As a result, the inner peripheral surface of the pocket can make point contact with the ball to reduce the contact width as much as possible, the slip resistance between the ball and the cage can be suppressed, and the rotational torque of the bearing can be reduced. Can do.

  An outer ring having an arcuate outer rolling surface formed on the inner periphery, an inner ring having an arcuate inner rolling surface facing the outer rolling surface on the outer periphery, and a cage between the two rolling surfaces In a deep groove ball bearing comprising a plurality of balls accommodated so as to be freely rollable via a steel plate, the retainer is formed by pressing from a steel plate and the surface thereof is subjected to diamond-like carbon treatment, and two annular holding plates The ball holding portions that bulge in a rectangular shape are formed at a plurality of equally spaced locations in the circumferential direction of the annular holding plate, and the ball holding portions are opposed to each other on the opening side to form a polygonal pocket. Is formed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a deep groove ball bearing according to the present invention, FIG. 2 (a) is a sectional view taken along the line II-II in FIG. 1, and FIG. FIG.

  The deep groove ball bearing 1 includes an outer ring 2 having an arc-shaped outer rolling surface 2a formed on the inner periphery and an inner ring formed with an arc-shaped inner rolling surface 3a facing the outer rolling surface 2a on the outer periphery. 3, a plurality of balls 4 accommodated between both rolling surfaces, a cage 5 that holds these balls 4 in a freely rolling manner, and seals 6, 6 attached to both ends of the outer ring 2. A predetermined type of lubricating grease is sealed inside the bearing to constitute a sealed deep groove ball bearing 1.

  The outer ring 2, the inner ring 3 and the ball 4 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching. On the other hand, the cage 5 is formed by subjecting a strip steel such as a cold rolled steel plate (JIS standard SPCC system or the like) to plastic processing such as press working or drawing.

  As shown in FIG. 2 (a), the cage 5 is configured such that the ball 4 is sandwiched between two annular holding plates 7 and 7 so as to be able to rotate. Each of the two annular holding plates 7 and 7 is formed with a ball holding portion 8 that bulges in a rectangular shape at a plurality of positions at equal intervals in the circumferential direction. Further, these two annular holding plates 7 and 7 are configured such that each ball holding portion 8 is opposed to the opening side, and the balls 4 are held in the substantially hexagonal pockets 9 formed thereby, Each ball holding portion 7 is fixed by a rivet 10.

  In this cage 50, each ball holding portion 8 of the annular holding plate 7 is formed such that the distance L between the opposing surfaces of the ball holding portion 8 is slightly larger than the diameter 2r of the ball 4. That is, a predetermined pocket clearance 2 e is provided in the pocket 9. And the inner peripheral surface which has a flat surface makes point contact with the ball | bowl 4, and the cage | basket 5 is guided to a rolling element. Thereby, the contact width S with the ball 4 can be reduced as much as possible as compared with the conventional corrugated cage, the slip resistance between the ball 4 and the cage 5 is suppressed, and the rotational torque of the bearing is reduced. be able to. Here, the shape of the hexagonal pocket 9 is illustrated, but the present invention is not limited to this, and the cage 5 according to the present invention has a flat surface in which the inner peripheral surface of the pocket 9 is in point contact with the ball 4. For example, it may be a polygon such as an octagon.

  Further, as means for reducing the rotational torque of the bearing, it is preferable to subject the surface of the cage 5 to DLC (diamond-like carbon) treatment and to form the balls 4 from ceramic. As a result, sliding friction between the ball 4 and the cage 5 can be remarkably suppressed, and torque loss (hysteresis loss) caused by deformation of the ball 4 on the rolling surfaces of the inner and outer rings (not shown) can be reduced. This can further reduce the rotational torque of the bearing. In particular, under conditions where minute wear powder is mixed in the lubricating oil, such as automobile transmission bearings, wear can be suppressed and sufficient durability against wear powder biting. Can be demonstrated.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The deep groove ball bearing according to the present invention can be applied to, for example, a deep groove ball bearing provided with a steel plate cage used in a transmission or the like.

It is a longitudinal cross-sectional view which shows one Embodiment of the rolling bearing which concerns on this invention. (A) is the II-II arrow directional cross-sectional view of FIG. (B) is the principal part enlarged view of (a). It is a longitudinal cross-sectional view which shows the conventional cage for deep groove ball bearings. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3.

Explanation of symbols

1 ... Deep groove ball bearing 2 ... Outer ring 2a ... Outer rolling surface 2b ... Inner diameter 3 ... .... Inner ring 3a ... Inner rolling surface 4 ... Ball 5 ... Retainer 6 ... Seal 7 ...・ ・ ・ ・ ・ Rolling holding plate 8 ・ ・ ・ ・ ・ ・ ・ ・ Ball holding part 9 ・ ・ ・ ・ ・ ・ ・ ・ Pocket 10 ・ ・ ・ ・ ・ ・ Rivet C ・ ・ ・ ・ ・ ・ ・ ・ Ball holding Center of the opening surface of the part e ... Pocket clearance L ... Distance r between pocket facing surfaces ... Ball radius S ... .... Contact width α ..... curvature radius

Claims (4)

An outer ring having an arcuate outer raceway formed on the inner circumference;
An inner ring in which an arc-shaped inner rolling surface facing the outer rolling surface is formed on the outer periphery;
In a deep groove ball bearing comprising a plurality of balls accommodated so as to be freely rollable between both rolling surfaces through a cage,
The cage is composed of two annular holding plates formed by pressing from a steel plate, and a ball holding portion is formed that bulges in a rectangular shape at a plurality of equally spaced locations in the circumferential direction of the annular holding plate. A deep groove ball bearing characterized in that the ball holding portions are opposed to each other on the opening side to form a polygonal pocket.   The deep groove ball bearing according to claim 1, wherein the surface of the cage is subjected to diamond-like carbon treatment.   The deep groove ball bearing according to claim 1, wherein the ball is made of ceramic.   The deep groove ball bearing according to claim 2 or 3, wherein the deep groove ball bearing is for an automobile transmission.

Images