JP2000291662A - Ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing capable of reducing the deformation of a cage caused by the centrifugal force while using an inexpensive crown-shaped cage, and capable of being used under high speed rotation. SOLUTION: A rolling element 3 is placed between an inner ring 1 and an outer ring 2, and held by a cage 4. The cage 4 has the shape of a crown, and one side surface of an annular body 6 has a pocket 5 partially opened for holding the rolling element 3 inside. A pitch circular diameter PCD of the pocket 5 of the cage 4 is larger than a center Q of a radial thickness of a circumferential wall cross section of the annular body 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball bearing requiring a high rotational speed, and more particularly to an improvement in a cage of a type called a crown.

[0002]

2. Description of the Related Art In home electric appliances and various devices, ball bearings having a crown-shaped cage are often used from the viewpoint of cost reduction. For example, in a motor for a vacuum cleaner, the upper limit rotational speed is improved in order to improve the suction force and reduce the size. The motor generally uses a deep groove ball bearing having an inner diameter of about 8 mm. The retainer of this ball bearing was a corrugated retainer made of an annular part of an iron plate, but was replaced with a low-cost crown retainer made of resin. Crowned cages can be manufactured inexpensively by injection molding, and when assembling ball bearings, it is only necessary to insert the cage between races in which balls are arranged at equal intervals in the circumferential direction. Costs can be reduced.

[0003]

However, the crown-shaped cage has an asymmetrical shape in the left and right directions, and is made of resin and is easily deformed by an external force as compared with a metal cage. Therefore, when used under high-speed rotation, the cage is deformed by centrifugal force,
It may hinder smooth rotation.

An object of the present invention is to provide a ball bearing which can reduce deformation of the cage due to centrifugal force while using an inexpensive crown-shaped cage, and can be used under higher speed rotation.

[0005]

According to a first aspect of the present invention, a ball bearing has a retainer for retaining a rolling element interposed between an inner ring and an outer ring. A cage, that is, a ball bearing that is a cage having a pocket partially opened on one side surface of an annular body and holding a rolling element therein at a plurality of circumferential positions of the annular body; The pitch circle diameter of the pocket is larger than the center of the radial thickness of the peripheral wall section of the annular body. The deformation of the crown cage due to the centrifugal force is determined by the torsional stiffness of the portion serving as the bottom wall of the pocket and the centrifugal force acting on the column portion between the pockets. On the other hand, by making the pitch circle diameter of the pocket larger than the center of the radial thickness of the circumferential wall cross section of the annular body as described above, in other words, the circumferential wall cross section is closer to the inner diameter side than the pitch circle diameter. By biasing, the cross-sectional area of the pocket bottom wall part increases,
The torsional stiffness of the pocket bottom wall is increased. Also,
The radius of the column from the bearing rotation center is reduced, and the centrifugal force acting on the column is reduced. For this reason, the deformation of the cage due to the centrifugal force is reduced, and the cage can be used under higher-speed rotation.

A ball bearing according to a second aspect of the present invention comprises:
A retainer for holding the rolling element interposed between the inner ring and the outer ring, the retainer having a pocket partially open on one side of the annular body and holding the rolling element therein; In a ball bearing provided at a plurality of positions in a circumferential direction of a body, a flange is formed on an outer peripheral surface of the annular body of the retainer on a pocket bottom side. In this way, by forming a flange around the pocket bottom side of the retainer,
The cross-sectional area of the pocket bottom wall portion of the retainer increases, and the torsional stiffness increases. Therefore, the deformation of the retainer due to the centrifugal force acting on the column is suppressed. Further, since the flange is provided on the outer diameter side, even if the retainer is deformed due to centrifugal force, the deformation causes the flange to separate from the outer ring, and the flange comes into sliding contact with the outer ring and becomes a resistance to rotation or holds. There is no wear of the vessel.

In the present invention, the retainer may have a shape in which the radial thickness of the cross section of the peripheral wall of the annular body decreases from the side face on the pocket bottom side to the side face on the pocket open side. In this way, by forming the shape in which the radial thickness of the cross section of the peripheral wall of the retainer decreases from the side surface on the pocket bottom side toward the side surface on the pocket open side, the pocket bottom wall portion where torsional stiffness is required The cross-sectional area of the column increases, and the mass at the tip of the column, where a reduction in centrifugal force is required, will decrease,
The effect of preventing the cage from being deformed by increasing the torsional stiffness and reducing the centrifugal force is further improved.

[0008] In the present invention, the retainer may have an end face concave portion that is concave from the distal end to the proximal end side in the pillar portion between the pockets of the annular body. By providing the end portions with recesses in the pillar portion in this way, the mass of the pillar portion on which the centrifugal force acts is reduced, and the deformation due to the centrifugal force is further reduced.

In the present invention, the retainer may have a peripheral concave portion that is recessed from an outer diameter surface or an inner diameter surface of the annular body in a pillar portion between pockets of the annular body. As described above, even when the peripheral portion is provided on the pillar portion, the mass of the pillar portion on which the centrifugal force acts is reduced, and the deformation due to the centrifugal force is further reduced.

In the present invention, the retainer may be a molded product of a synthetic resin composition, and the synthetic resin composition may be composed of only a synthetic resin or a combination of a synthetic resin and fibers. Even when the retainer is a molded product of a synthetic resin composition composed of only a synthetic resin, the above-described configurations of the present invention can suppress deformation due to centrifugal force. Further, since the composition is composed only of a synthetic resin, it can be manufactured at low cost. When the cage is a molded body of a synthetic resin composition comprising a synthetic resin and fibers, the strength of the cage is increased by the reinforcing action of the fibers, and the deformation due to centrifugal force can be further reduced.

In the present invention, the retainer is made of a synthetic resin,
It may be a molded article of a synthetic resin composition comprising fibers and lubricating oil. As described above, when the synthetic resin composition contains the lubricating oil, the lubrication performance in the ball bearing during high-speed rotation can be enhanced. Further, since the fibers are included, the strength of the retainer also increases.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. This ball bearing comprises an inner ring 1 and an outer ring 2
And a plurality of rolling elements 3 arranged in the circumferential direction are interposed between
These rolling elements 3 are held by a so-called crown-shaped holder 4. The inner ring 1 and the outer ring 2 have raceway grooves 1a and 2a having a circular arc cross section on which the rolling elements 3 roll, and this ball bearing is a deep groove ball bearing. Inner and outer rings 1 and 2 and rolling elements 3
Is made of steel, for example, and the retainer 4 is a molded body of a synthetic resin composition.

The retainer 4 has pockets 5 for holding the rolling elements 3 therein at a plurality of circumferential positions of the annular body 6 as shown in a perspective view in FIG. Each pocket 5
Part of the annular body 6 is open to one side. The inner surface of each pocket 5 has a concave spherical shape along the outer surface of the rolling element 3. The portion between the adjacent pockets 5 and 5 of the annular body 6 becomes the pillar 7. In this embodiment, in the cage 4 having such a configuration, the pitch circle diameter PCD of the pocket 5 is used.
Is made larger than the diameter formed by the center Q of the radial thickness of the cross section of the peripheral wall of the annular body 6. Accordingly, the radial thickness H from the position corresponding to the pitch circle diameter PCD of the retainer 4 to the retainer inner diameter surface and the entire radial thickness W of the retainer 4 are as follows: H> W / 2 Has become. The outer diameter surface and the inner diameter surface of the retainer 4 are cylindrical surfaces. The pitch circle diameter PCD of the pocket 5 is a diameter of a circle passing through the center of the rolling element 3 held in each pocket 5, and when the inner surface of the pocket 5 is spherical as in this example, , The diameter of a circle passing through the center of curvature of the spherical inner surface of each pocket 5.

According to the ball bearing having this configuration, the deformation of the retainer 4 due to the centrifugal force caused by the rotation of the bearing is determined by the torsional stiffness of the pocket bottom wall portion 6a and the centrifugal force acting on the column portion 7. You. On the other hand, in this embodiment, the pitch circle diameter PCD of the pocket 5 is larger than the center Q of the radial thickness of the circumferential wall cross section of the annular body 6, and the circumferential wall cross section has an inner diameter smaller than the pitch circle diameter PCD. As a result, the sectional area of the pocket bottom wall portion 6a is larger than that of a crown-shaped cage in which the center of the cross section of a general peripheral wall is matched with the pitch circle diameter PCD. The radius from is reduced. Therefore, the torsional stiffness of the pocket bottom wall portion 6a increases, and the centrifugal force acting on the column portion 7 decreases.
For this reason, the deformation of the retainer 4 due to the centrifugal force is reduced, and the retainer 4 can be used under higher speed rotation.

FIGS. 3 to 11 show various modifications of the retainer 4 used in the ball bearing shown in FIG. The cage 4 of each of these modified examples will be described in terms of a common configuration. In each case, the pocket 5 for holding the rolling element 3 is provided with an annular body 6.
Are provided at a plurality of positions in the circumferential direction, and each pocket 5
Is partially open on one side surface of the annular body 6. The inner surface of each pocket 5 has a concave spherical shape along the outer surface of the rolling element 3. Adjacent pockets 5,5 of annular body 6
The portion between them becomes the pillar 7. In each case, the pitch circle diameter PCD of the pocket 5 of the cage 4 is the same as in the example of FIG.
Is larger than the center Q of the radial thickness of the cross section of the peripheral wall of the annular body 6.

The cage 4 in the example of FIG. 3 has a flange 8 formed on the outer peripheral surface of the annular body 6 on the pocket bottom side. Due to the formation of the flange 8, the outer diameter of the annular body 6 on the pocket open side is smaller than the outer diameter of the pocket bottom side. When the flange 8 is formed in this manner, the flange 8 increases the cross-sectional area of the pocket bottom wall portion of the retainer 4 and increases the torsional rigidity. Therefore, the deformation of the retainer 4 due to the centrifugal force acting on the column 7 is further reduced. Further, since the flange 8 is provided on the outer diameter side, even if the retainer 4 is deformed so that the tip of the column portion 7 bends to the outer diameter side due to centrifugal force, the flange 8 is deformed in a direction away from the outer ring, The flange 8 does not come into sliding contact with the outer race 2 to cause rotation resistance, and the cage 4 does not wear. When the flange 8 is provided, the pitch circle diameter PCD of the pocket 5 of the retainer 4 (FIG. 1)
May be matched with the center of the radial thickness of the cross section of the peripheral wall excluding the flange 8 of the annular body 6.

The cage 4 in the example of FIG. 4 has a shape in which the radial thickness d of the cross section of the peripheral wall of the annular body 6 decreases from the side face 4a on the bottom side of the pocket to the side face 4b on the open side of the pocket. It is. Specifically, the outer diameter surface of the annular body 6 is a conical surface having a smaller diameter toward the side surface 4b on the pocket opening side, and the inner diameter surface is a cylindrical surface. The inner and outer surfaces of the annular body 6 may be conical surfaces. As described above, the radial thickness d of the cross section of the peripheral wall of the retainer 4 is the side surface 4a on the pocket bottom side.
Of the pocket bottom wall portion 6a where torsional stiffness is required is increased, and the column tip end side where a reduction in centrifugal force is required. Is reduced, and the effect of preventing cage deformation due to an increase in torsional stiffness and a reduction in centrifugal force is further improved. In the retainer 4 in the example of FIG. 4, as shown in FIG. 5, a flange 8 may be formed on the outer peripheral surface of the annular body 6 on the pocket bottom side.

The retainer 4 in the example shown in FIG. 6 has an end face concave portion 9 which is recessed from the distal end to the proximal end side in each pillar portion 7 between pockets of the annular body 6. The end face concave portion 9 has a depth equal to or greater than the axial depth of the pocket 5.
Further, the annular body 6 is formed with a flange 8 on the outer peripheral surface on the side of the pocket bottom side. More specifically, the end face concave portion 9 has a depth to a side surface position of the flange 8,
Due to the formation of the end face concave portion 9, the column portion 7 has a shape divided into two in the circumferential direction of the retainer. The flange 8
Need not necessarily be provided. Thus, by providing the end face concave portion 9 in the pillar portion 7, the pillar portion 7 on which the centrifugal force acts is provided.
Is reduced, and deformation due to centrifugal force is further reduced.

In the example of FIG. 6, the end face recess 9 is
As shown in the example, the pocket 5 may be shallower than the axial depth. In the example of FIG. 7, the formation of the end surface concave portion 9 causes the column portion 7 on the tip side from the bottom surface of the end surface concave portion 9 to become a pair of claw-like portions 7 along the concave curved surface of the pocket inner surface.
a. When the end face concave portion 9 is shallower than the axial depth of the pocket 5 as in the example of FIG. 7, the peripheral wall of the annular body 6 of the retainer 4, as shown in each example of FIGS. The cross section may have a shape in which the thickness in the radial direction decreases from the side face on the pocket bottom side to the side face on the pocket open side. 8 and 9, the outer surface of the annular body 6 is a conical surface, and the inner surface is a cylindrical surface. The example of FIG. 8 is an example in which there is no flange on the outer diameter,
The example of FIG. 9 is an example in which a flange 8 is formed on the outer peripheral surface of the annular body 6 on the pocket bottom side.

As shown in the examples of FIGS. 10 and 11, the retainer 4 is provided on the pillar 7 which is a portion between the pockets of the annular body 6, with a peripheral surface recessed from the outer diameter surface of the annular body 6. It may have the concave portion 10. The example of FIG. 10 is the example of FIG. 3, that is, the example in which the outer surface and the inner surface of the annular body 6 are cylindrical surfaces and the flange 8 is provided, and the peripheral surface recess 10 is provided. 11 is an example of FIG. 5, that is, an example in which the outer diameter surface of the annular body 6 is a conical surface, the inner diameter surface is a cylindrical surface, and the flange 8 is provided, and the peripheral surface concave portion 10 is provided. Things. As shown in FIGS. 10 and 11,
Even when the peripheral surface concave portion 10 is provided, the mass of the column portion 7 on which the centrifugal force acts is reduced, and the deformation due to the centrifugal force is further reduced. In addition, the peripheral surface concave portion 10 may be provided in the column portion 7 so as to be concave from the inner diameter surface of the annular body 6.

An example of the material of the retainer 4 in each of the above embodiments will be described. The retainer 4 may be a molded body of a synthetic resin composition consisting of only a synthetic resin, in which case the material cost is low. The retainer 4 may be a molded article of a synthetic resin composition comprising a synthetic resin and fibers. In this case, the strength of the retainer is increased by the reinforcing action of the fibers, and the deformation due to centrifugal force can be further reduced. Carbon fibers or the like are used as fibers to be mixed in the cage 4. Also,
The retainer 4 may be a molded body of a synthetic resin composition comprising a synthetic resin, fibers, and a lubricating oil. In this case, in addition to the reinforcing effect of the fibers, the lubrication performance in the ball bearing during high-speed rotation is enhanced. Can be

[0022]

According to the ball bearing of the present invention, deformation of the cage due to centrifugal force can be reduced while using an inexpensive crown-shaped cage, and the ball bearing can be used under higher speed rotation.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a ball bearing according to an embodiment of the present invention.

FIG. 2 is a perspective view of the retainer.

FIG. 3 is a perspective view of a modified example of the retainer.

FIG. 4 is a perspective view of another modified example of the retainer.

FIG. 5 is a perspective view of still another modified example of the retainer.

FIG. 6 is a perspective view of still another modified example of the retainer.

FIG. 7 is a perspective view of still another modified example of the retainer.

FIG. 8 is a perspective view of still another modified example of the retainer.

FIG. 9 is a perspective view of still another modified example of the retainer.

FIG. 10 is a perspective view of still another modified example of the retainer.

FIG. 11 is a perspective view of still another modified example of the retainer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Inner ring 2 ... Outer ring 3 ... Rolling element 4 ... Retainer 5 ... Pocket 6 ... Annular body 7 ... Column part 8 ... Flange part 9 ... End face concave part 10 ... Peripheral surface concave part PCD ... Pitch circle diameter Q ... Peripheral wall cross section Center of radial thickness

Claims (7)

[Claims] 1. A retainer for holding a rolling element interposed between an inner ring and an outer ring, the retainer being partially open on one side surface of an annular body to hold the rolling element therein. In a ball bearing having pockets at a plurality of positions in a circumferential direction of the annular body, a pitch circle diameter of the pockets of the retainer is larger than a center of a radial thickness of a cross section of a peripheral wall of the annular body. And ball bearings. 2. A retainer for holding a rolling element interposed between an inner ring and an outer ring, the retainer being partially open on one side surface of an annular body to hold the rolling element therein. A ball bearing having a plurality of pockets at a plurality of positions in a circumferential direction of the annular body, wherein a flange is formed on an outer peripheral surface of the annular body of the retainer on a pocket bottom side. 3. The cage according to claim 1, wherein the retainer has a shape in which a radial thickness of a cross section of a peripheral wall of the annular body decreases from a side surface on a pocket bottom side to a side surface on a pocket open side. Ball bearings. 4. The holding device according to claim 1, wherein the retainer has an end recessed from a distal end to a proximal end in a pillar portion between pockets of the annular body. Ball bearings. 5. The retainer according to claim 1, wherein a pillar portion which is a portion between pockets of the annular body has a peripheral concave portion recessed from an outer diameter surface or an inner diameter surface of the annular body.
The ball bearing according to any one of the above. 6. The molded article of a synthetic resin or a synthetic resin composition comprising a synthetic resin and fibers.
A ball bearing according to claim 5. 7. The molded article of a synthetic resin composition comprising a synthetic resin, fibers, and a lubricating oil.
A ball bearing according to claim 5.