JP2003314557A - Cage and rolling bearing incorporating this cage - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a cage which is low in torque and excellent in durability and quietness, and a rolling bearing incorporating the cage. A crown-shaped cage (2) is capable of holding a plurality of spherical rolling elements (4) at predetermined intervals so as to freely roll, and has a plurality of openings (F) formed in a part in the circumferential direction. And a plurality of projections 8a and 8b are provided at predetermined intervals on the inner surface of at least three or more pockets. These projections are provided at respective symmetrical positions with respect to a plane W extending in the axial direction of the cage 2 through the center M of the pocket and the axis of the cage, and are also provided on the inner periphery from the outer edge E1 of the crowned cage. It extends over the edge E2, and the cross section of each projection has the same shape as each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cage for holding a plurality of rolling elements at predetermined intervals so that they can roll freely, and a rolling bearing incorporating the cage.

[0002]

2. Description of the Related Art Conventionally, various rolling bearings have been known as mechanical elements for rotating and supporting a rotating body, and these rolling bearings are, for example, corrugated cages or cage-shaped holdings depending on their applications. Container, crown-shaped cage, etc. are incorporated. Each of such cages is configured to be capable of rollingly holding a plurality of rolling elements at predetermined intervals, and is formed of, for example, a steel material or a resin material.

[0003]

By the way, in recent years, rolling bearings have been required to have high quietness, and there is a problem that it is difficult for rolling bearings incorporating a conventional cage to sufficiently satisfy the requirements. Has occurred. This problem will be described by taking a crown-shaped cage as an example.
As shown in FIGS. 3 (a) and 3 (b), the crown-shaped cage 100 is provided with a plurality of pockets 104 for holding the plurality of rolling elements 102 at equal intervals and rotatably. The inner diameter D1 of each pocket 104 is set to be slightly larger than the diameter D2 of the rolling element 102. Therefore, pocket 1
04 and the rolling element 102, a pocket clearance Ps is formed, and as a result, in the operating state and the stationary state of the rolling bearing, the crown cage 100 (or the rolling element 102).
Can be freely moved in the directions of arrows S1, S2 and S3 (see FIGS. 4A to 4C) by filling the pocket clearance Ps. In this case, in particular, as shown in FIG. 4C, the amount by which the crown cage 100 (or the rolling element 102) moves in the axial direction S3 of the rolling bearing becomes larger than Ps and larger than S1 and S2. turn into.

Crown-shaped cage 100 (or rolling element 102)
When the amount of movement of the rolling bearing increases, an abnormal noise called a cage noise may occur during the operation of the rolling bearing. This abnormal noise is particularly likely to occur when a lubricant (grease or the like) is filled in the rolling bearing. As a method of preventing the generation of abnormal noise, a method of reducing the inner diameter D1 of each pocket 104 to reduce the pocket clearance Ps can be considered. But,
In this method, the contact area (friction amount) between the rolling element 102 and the pocket 104 is increased, so that not only the torque during the operation of the rolling bearing is increased, but also the crown-shaped cage 100 and the rolling element due to wear and abrasion are increased. It affects the durability of the bearing. Further, according to this method, a larger amount of the lubricant attached to the surface of the rolling element 102 is scraped off at the edge portion (edge portion on the opening side) of the pocket 104. Therefore, the lubrication state between the rolling elements 102 and the pockets 104 deteriorates, and not only the rolling elements 102 and the pockets 104 but also the wear and wear of the inner and outer raceway surfaces of the rolling bearing easily progress. As a result, the quietness of the rolling bearing may be impaired. The present invention has been made to solve such a problem, and an object thereof is to provide a cage excellent in durability and quietness while achieving low torque, and a rolling bearing incorporating the cage. Especially.

[0005]

In order to achieve such an object, the cage of the present invention is capable of holding a plurality of rolling elements at predetermined intervals and rotatably, and partly. It has a plurality of pockets in which openings are formed, and a plurality of protrusions are provided at predetermined intervals on the inner surface of at least three or more pockets. Further, the rolling bearing of the present invention,
It is possible to hold a plurality of rolling elements, a track member that supports a shaft that rotates or oscillates due to the rolling movement of these rolling elements, and each rolling element so as to be rollable at predetermined intervals and partially. A retainer having a plurality of pockets formed with openings is provided, and a plurality of protrusions are provided at predetermined intervals on the inner surface of at least three or more pockets.
In this case, the plurality of protrusions are respectively provided at symmetrical positions with respect to a plane extending in the axial direction of the cage through the center of the pocket and the axial center of the cage, and at the same time, from the outer peripheral edge to the inner peripheral edge of the cage. The protrusions extend over the same length, and the cross sections of the respective protrusions have the same shape. The projection amount of the plurality of projections is set so that the rolling element is held in contact with only the pocket surface edge of the opening and the crown of each projection when the rolling element is held in the pocket. . Further, the opening is formed along the axial direction,
The plurality of protrusions are provided on the inner surface of the pocket facing the opening. The cross sections of the plurality of protrusions are, respectively,
It is possible to select an arc shape, a trapezoidal shape, or a triangular shape.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a cage and a rolling bearing incorporating the cage according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, a crown type cage and a ball bearing incorporating the crown type cage will be described as an example, but the present invention is not limited to this, and the technical idea of the present invention is that the rolling element is a pocket. The present invention can be applied to all types of cages that are retained by, and bearings in which these cages are incorporated (for example, rolling bearings including thrust bearings and radial bearings).

As shown in FIGS. 1 (a) and 1 (b), the crown-shaped cage 2 of the present embodiment is capable of holding a plurality of rolling elements (balls) 4 at predetermined intervals and in a rollable manner. It is possible and the substantially annular cage-shaped cage 2 has a plurality of pockets 6 each having an opening F formed in a part in the circumferential direction.
A plurality of protrusions 8a, 8b are provided on the inner surface of the device at predetermined intervals. In the present embodiment, as an example,
The case where two protrusions 8a and 8b are provided on the inner surface of each pocket 6 is shown. In addition, the plurality of protrusions 8a, 8b
The number of pockets 6 provided with is at least three out of the total number of cage pockets. The opening F is formed along the circumferential direction, and the two protrusions 8a and 8b are provided on the inner surface of the pocket 6 facing the opening F.
As is apparent from FIG. 1 (b) in which the crown-shaped cage 2 is developed on a plane, these protrusions 8a and 8b form the center M of the pocket 6 and the axial center of the cage 2 (XX in FIG. 3). Through the outer peripheral edge E1 of the crown-shaped cage 2 and the inner peripheral edge E2 of the crown-shaped cage 2 respectively. 8
The cross sections of a and 8b have the same shape.

In this embodiment, the two protrusions 8a,
The cross sections of 8b each have an arc shape. In this case, the protrusion amount of each projection 8a, 8b is such that the rolling element 4 holds the rolling element 4 in the pocket 6 and the rolling element 4 has pocket surface edges Fa, Fb of the opening F and the crown Ta of each projection 8a, 8b. , Tb are set in contact with and held. In addition, the arc size (the size of the arc), the arc center (the center of curvature), the projection angle (the direction of the projection), etc. for defining the projection amount of each of the projections 8a and 8b are determined by the crown cage 2 and the crown shape. It is possible to set the optimum value depending on the purpose of use, environment of use, purpose of use, etc. of the rolling bearing in which the cage 2 is incorporated.

In such a structure, the pocket face edges Fa, Fb of the opening F and the crown T of each projection 8a, 8b are formed.
When the inscribed circle R that contacts a and Tb is defined, this inscribed circle R becomes the virtual pocket diameter. The inner surface of the other pocket 6 not provided with the protrusions 8a and 8b can be set to various well-known inner surface shapes such as a spherical surface, a cylindrical surface shape, and a conical surface shape. That is, the shape of the inner surface of the other pocket 6 is such that the surface of the rolling element 4 relative to the inner surface of the other pocket 6 in a state where the rolling element 4 is held in the pocket 6 in which the virtual pocket (inscribed circle R) is defined. It is possible to select an arbitrary inner surface shape as long as it does not touch.

The crown-shaped cage 2 as described above can be integrally molded by injection molding. However, when using a molding method (for example, an axial draw method) of separating the molded product from the mold in the axial direction of the cage, the protrusions 8a, 8b
It is necessary to perform the detaching work in consideration of the protrusion angle (direction of the protrusion). That is, when the molded product (that is, the crown-shaped cage 2) is separated from the mold, it is preferable to perform the separation work so that an unexpected external force is not applied to the protrusions 8a and 8b.

Further, the respective projections 8a, 8b contacting the rolling element 4
The contact parts (specifically, the crown portions Ta and Tb) of the rolling bearings are worn and worn by the long-term use of the rolling bearing, are damaged by the collision between the rolling elements 4 and the protrusions 8a and 8b during the bearing assembly, and Deformation and the like due to the rolling element 4 and the projections 8a and 8b being pressed against each other are likely to occur. Therefore, in order to improve the durability of this contact portion, it is preferable to form the contact portion in a planar shape.

Although not shown in particular, it goes without saying that the technique of the present invention can be applied to a rolling bearing incorporating the above-mentioned cage. In this case, the rolling bearing is provided with a raceway member that supports a shaft that rotates or oscillates due to the rolling movement of each rolling element 4. By combining this raceway member and a cage, it is possible to reduce the torque. It is possible to realize a rolling bearing which is excellent in durability and quietness while being achieved. As a track member,
For example, the outer ring and the inner ring are applicable. Further, the sealing plate (contact type or non-contact type seal or shield) is arbitrarily selected according to the purpose of use and environment of use of the rolling bearing.

As described above, according to this embodiment, the two projections 8a, 8b are provided on the inner surface of each pocket 6 at a predetermined interval, so that the rolling element 4 becomes the pocket surface edges Fa, Fb in the pocket 6. Head Ta, T of each protrusion 8a, 8b
Since it is held in contact with only b, the contact area (friction amount) between the rolling element 4 and the inner surface of the pocket 6 can be reduced. As a result, it is possible to reduce the torque of the rolling bearing during operation, and it is possible to prevent the durability of the crown cage 2 and the rolling bearing from being deteriorated due to wear and abrasion. Further, two protrusions 8 are provided on the inner surface of each pocket 6.
By providing a and 8b, a gap (space) is formed between the rolling element 4 and the inner surface of the other pocket 6 where these protrusions 8a and 8b are not provided, and the lubricant is added to this gap during the bearing operation. It is possible to always retain. In this case, it is possible to suppress the problem that the lubricant adhering to the surface of the rolling element 4 is scraped off more by the outer peripheral edge E1 and the inner peripheral edge E2 of the pocket surface edges Fa and Fb. Becomes As a result, the lubricity between the inner surface of the pocket 6 and the rolling element 4 can always be stabilized, so that not only the rolling element 4 and the pocket 6 but also the wear and wear of the raceway surfaces of the inner and outer races of the rolling bearing can be prevented. Can be reduced. Further, according to such an effect, it is possible to realize a cage excellent in durability and quietness while achieving a low torque, and a rolling bearing incorporating the cage.

The present invention is not limited to the above-described embodiment, but can be modified in various ways as follows. As a first modification, for example, as shown in FIG. 2A, the two protrusions 8a and 8b may each have a trapezoidal cross section. In this case, each protrusion 8a, 8b
The sectional shape of is composed of three sides, and the crown portions Ta and Tb thereof are planar, and the rolling elements 4 are in contact with these planar crown portions Ta and Tb. Note that, also in this modified example, each of the protrusions 8a, 8b is similar to the above-described embodiment.
The protrusion amount, the trapezoidal size (the size of the trapezoid), the trapezoid center, and the protrusion angle (the direction of the protrusion) for defining the protrusion amount are incorporated in the crown-shaped cage 2 and the crown-shaped cage 2. The optimum value can be set according to the purpose of use of the rolling bearing, the environment of use, the application, etc.

As a second modification, for example, as shown in FIG. 2B, the two protrusions 8a and 8b may each have a triangular cross section. In this case, each protrusion 8a, 8b
The cross-sectional shape of is composed of two sides, and its tops Ta, Tb are tapered, and these tops Ta, T are tapered.
The rolling element 4 comes into contact with b. Note that, also in this modified example, similarly to the above-described embodiment, each protrusion 8a,
The protrusion amount of 8b, and the triangular size (triangle size), the center of the triangle, and the protrusion angle (direction of the protrusion) for defining the protrusion amount are determined by the crown-shaped cage 2 and the crown-shaped cage 2. It is possible to set the optimum value according to the purpose of use, environment of use, application, etc. of the rolling bearing to be incorporated. In addition, in the above-described embodiment, the first and second modifications,
It is assumed that the two protrusions 8a and 8b are provided on the inner surface of each pocket 6, but the present invention is not limited to this, and the crown-shaped cage 2 and the rolling element incorporating the crown-shaped cage 2 are not limited thereto. It is possible to set the optimum number (for example, an even number of 2 or more) according to the purpose of use, the environment of use, the application of the bearing.

[0016]

According to the present invention, it is possible to realize a cage excellent in durability and quietness while achieving a low torque, and a rolling bearing incorporating this cage.

[Brief description of drawings]

1A and 1B are views showing a structure of a cage according to an embodiment of the present invention, FIG. 1A is a partial perspective view of a cage in which a plurality of pockets are formed, and FIG. The figure which shows the state in which the virtual pocket diameter is comprised in the pocket by several protrusions.

FIG. 2 (a) is a diagram showing a structure of a pocket of a cage according to a first modification of the present invention, and FIG. 2 (b) is a structure of a pocket of a cage according to a second modification of the present invention. FIG.

FIG. 3A is a perspective view of a conventional crown-shaped cage, and FIG.
FIG. 4 is a diagram showing a state in which the rolling elements are held in the pocket of the cage shown in FIG.

FIG. 4A to FIG. 4C are views showing how the crown-shaped cage (or rolling element) moves.

[Explanation of symbols]

2: Crown type cage 4: Rolling element 6: Pocket 8a, 8b: protrusion E1: Outer edge of crown cage E2: Inner peripheral edge of crown type cage F: Opening M: Center of pocket W: A plane extending in the axial direction of the cage XX: Cage axis

Claims (14)

[Claims] 1. A retainer capable of holding a plurality of rolling elements at a predetermined interval so as to be rollable, and having a plurality of pockets each having an opening formed in at least three pockets. A retainer characterized in that a plurality of protrusions are provided at predetermined intervals on the inner surface of the retainer. 2. The plurality of protrusions are respectively provided at symmetrical positions with respect to a plane extending in the axial direction of the cage, passing through the center of the pocket and the axial center of the cage, and at the same time, from the outer peripheral edge to the inner peripheral side of the cage. The cage according to claim 1, wherein the cage extends along the edge, and the cross sections of the respective protrusions have the same shape. 3. The projection amount of the plurality of projections is set such that the rolling element is held in contact with only the pocket surface edge of the opening and the crown of each projection when the rolling element is held in the pocket. The cage according to claim 1 or 2, wherein the cage is provided. 4. The opening is formed along the axial direction, and the plurality of protrusions are provided on the inner surface of the pocket facing the opening. The cage described in. 5. The cage according to claim 1, wherein each of the plurality of projections has an arc shape in cross section. 6. The cage according to claim 1, wherein each of the plurality of protrusions has a trapezoidal cross section. 7. The cage according to claim 1, wherein each of the plurality of protrusions has a triangular shape in cross section. 8. A plurality of rolling elements, a track member that supports a shaft that rotates or oscillates due to the rolling motion of these rolling elements, and each rolling element can be rotatably held at predetermined intervals. In a rolling bearing including a retainer having a plurality of pockets, some of which have openings, a plurality of protrusions are provided at predetermined intervals on the inner surface of at least three or more pockets. Characteristic rolling bearing. 9. The plurality of protrusions are respectively provided at symmetrical positions with respect to a plane extending through the center of the pocket and the axial center of the retainer in the axial direction of the retainer, and at the same time, from the outer peripheral edge of the retainer to the inner periphery. 9. The rolling bearing according to claim 8, wherein the rolling bearing extends along the edge, and the cross sections of the respective protrusions have the same shape. 10. The projection amount of the plurality of projections is set such that the rolling element is held in contact with only the pocket surface edge of the opening and the crown of each projection when the rolling element is held in the pocket. The rolling bearing according to claim 8 or 9, characterized by being provided. 11. The opening is formed along the axial direction, and the plurality of protrusions are provided on the inner surface of the pocket facing the opening. Rolling bearing described in. 12. The rolling bearing according to claim 8, wherein each of the plurality of protrusions has an arc shape in cross section. 13. The rolling bearing according to claim 8, wherein each of the plurality of protrusions has a trapezoidal cross section. 14. The rolling bearing according to claim 8, wherein each of the plurality of protrusions has a triangular shape in cross section.