CN113048151A

CN113048151A - Cage for a rolling bearing and rolling bearing

Info

Publication number: CN113048151A
Application number: CN201911368108.5A
Authority: CN
Inventors: 雷飞
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2021-06-29

Abstract

The invention relates to a cage for a rolling bearing and a rolling bearing, the cage having a cage ring (41) and cage webs projecting from at least one axial end face of the cage ring (41), wherein pockets (43) for receiving rolling bodies (3) of the rolling bearing are formed between two adjacent cage webs, wherein each cage web has a support beam (44) projecting from the cage ring (41) and a catch (42) projecting at least partially to both circumferential sides from an end of the support beam (44), wherein a radially thickened bead (48) of the cage web is formed in a rolling body circumferential support region of the cage web; the rolling bearing comprises the retainer.

Description

Cage for a rolling bearing and rolling bearing

Technical Field

The invention relates to the field of bearings. The invention relates in particular to a cage for a rolling bearing and to a rolling bearing comprising such a cage.

Background

A conventional rolling bearing includes an outer ring and an inner ring that are concentrically arranged, and includes rolling bodies arranged between the outer ring and the inner ring. The rolling bearing further comprises a cage to isolate the rolling bodies and to guide and retain the rolling bodies within the bearing. One common cage design is the snap cage design, which designs one end of the cage to be open, and the cage can be axially mounted on the premise of providing sufficient axial limit, simplifying the assembly process of the rolling bearing such as a ball bearing. For example, US patent document US 6,416,230B 1 discloses a snap-type cage for deep groove ball bearings. For another example, chinese patent document CN 101978181 also discloses a ball bearing retainer and a ball bearing including the same. Patent document WO 2015/090304 a1 also discloses a snap-type holder.

However, with the development of automobile electrification, the requirements for the rotational speed of rolling bearings such as deep groove ball bearings are increasing. Cages according to the current solution, in particular nylon cages, can exhibit cage breakage in some applications at high rotational speeds. The main reason for failure due to breakage is that the centrifugal force of the cage is proportional to the square of the rotational speed, and at high rotational speeds the centrifugal force increases substantially, and the load borne by the cage exceeds the strength limit of the material, particularly nylon material.

Disclosure of Invention

The object of the present invention is to provide a light cage, in particular a snap cage, with a completely new design, which has low friction properties and is suitable for high rotational speed applications.

This object is achieved by a cage for a rolling bearing. The cage is designed as a snap-in cage, i.e. the cage has a cage ring and cage webs projecting from at least one axial end face of the cage ring, wherein pockets for receiving rolling bodies of a rolling bearing are formed between two adjacent cage webs.

According to the inventive design, each cage bar comprises a support beam projecting from the cage ring and a catch projecting from the end of the support beam at least partially to both sides in the circumferential direction, wherein the reinforcement of the cage bar is embodied in the radial direction in the circumferential support region of the rolling bodies of the cage bar.

In the context of the invention, the rolling bearing comprises an outer ring and an inner ring which are arranged coaxially and rolling bodies which are arranged between the outer ring and the inner ring. The present invention is not limited to the structure and materials of the outer race and the inner race. A cage is coaxially disposed between the outer race and the inner race to isolate the individual rolling bodies and to guide and retain the rolling bodies within the rolling bearing. The rolling bodies can be designed as any type of rolling bodies that are adapted to the cage, preferably as spherical rolling bodies, i.e. balls.

In the context of the present description, unless otherwise stated, "axial", "circumferential" and "radial" relate to the axis of rotation or the center axis of the outer ring, inner ring and cage of the rolling bearing.

The cage is configured as a snap-in cage as described above. The cage can be used for a rolling bearing with a single row of rolling bodies, in which case circumferentially distributed cage bars project from one axial end face of the cage ring in the same axial direction, whereby a row of circumferentially distributed pockets is formed on the axial side. The cage can also be used for rolling bearings with double rows of rolling elements, in which case two rows of circumferentially distributed cage bars project in each case from the two axial end faces of the cage ring in opposite axial directions, whereby a row of circumferentially distributed pockets is formed on each axial side of the cage ring. In the case of cages for double row rolling elements, the pockets of the cage in both rows can be arranged in axial alignment, one after the other, and also in axial non-alignment, i.e. in the circumferential direction, with a corresponding offset.

The reinforcing rib is configured in the rolling body circumferential supporting area of the retainer beam, so that the strength of the retainer beam in the rolling body circumferential supporting area can be enhanced. Meanwhile, under the condition of thinner design of the supporting beam part, namely under the condition that the supporting beam has smaller radial thickness, the area of a circumferential supporting surface for limiting or supporting the rolling body in the circumferential direction is properly increased by locally arranging the reinforcing ribs on the beam of the retainer, and the support stability of the rolling body is favorably ensured in the light weight design of the retainer. At the same time, the cage ring can also be designed to be thin, so as to reduce the overall weight of the cage.

The cage designed according to the invention is preferably produced in one piece. The holder may be made of a metallic material or a non-metallic material. The non-metallic cage material is, for example, a polymer or a composite thereof, such as nylon.

In a particularly preferred embodiment, the cage is a nylon cage. The nylon material holder has better toughness after obtaining certain humidity. In addition, the nylon cage is lighter than a metal cage, has small centrifugal force, and is suitable for high-rotation-speed application occasions.

In a preferred embodiment, the circumferential support surface of the rolling body, which is formed by the support beams, the catches and the reinforcing ribs, is spherical. In this case, the rolling bodies can be designed in particular as balls. The contour of the circumferential support surface of the cage is thereby matched to the contour of the rolling body, which can provide better circumferential support for the rolling body. The opening formed by the two catches of the same pocket is designed such that the opening is smaller than the ball diameter while ensuring assembly. The two catches and the holder ring jointly realize an axial limiting function.

In this case, the reinforcing rib may include two arc-shaped sections extending from the two catches, respectively, toward the cage ring along the contour of the rolling element circumferential support surface, and a connecting section connecting the two arc-shaped sections in the circumferential direction. The two arc segments do not extend to the cage ring. In this way, the strength of the cage bar, in particular of the circumferential support region of the cage bar, can be advantageously ensured and the rolling bodies can be provided with circumferential support surfaces by the stiffening webs on each cage bar, which are designed like an H.

In this case, the support beam preferably extends in an arc-like manner at an angle to the axial direction and the latching jaws extend substantially at the same radial level, i.e. approximately in a circumferential plane. The radial height can be adapted to the radial position of the rolling bodies of the rolling bearing as required. The design of the clamping jaw can also ensure the circumferential support stability of the rolling body. In this case, the arc-shaped structure of the support beam can effectively avoid stress concentration.

In an advantageous embodiment, the support beam extends from the cage ring obliquely to the axial direction toward the radial inside, and the reinforcement is formed on the radial inside of the cage beam. This design is particularly advantageous for meeting the axial assembly requirements of the cage. In particular, the cage can be designed to be lightweight, and the support beams can be designed to be particularly lightweight. Therefore, when the cage is installed, when rolling bodies such as balls enter the pocket, the clamping claws on two sides of the pocket elastically deform towards the outer side of the pocket along the circumferential direction, and the supporting beams and the clamping claws can also deform inwards along the radial direction, so that the rolling bodies can enter the pocket conveniently, and the cage has better installation performance. In this case, the size of the opening formed by the two catches of each pocket can also be made smaller than in the prior art, owing to the good elasticity of the cage in the radial direction, thus providing better axial retention capability.

Particularly advantageously, the distance of the outer circumferential surface of the catch from the center axis of the cage is less than or equal to the pitch circle radius of the cage. The guidance of the cage is thereby effected only by the inner limiting points and not by the outer limiting points. Compared with the existing retainer scheme, the whole contact area of the retainer and the rolling body is smaller, the friction force is smaller, and the whole efficiency of the bearing is improved. Furthermore, this makes it possible, on the one hand, to achieve better installation performance as described above, and, on the other hand, to reduce the weight of the cage while ensuring sufficient support.

In an alternative and advantageous embodiment, the supporting beam extends from the cage ring obliquely to the axial direction towards the radial outside, the reinforcing rib being configured radially outside the cage ring. This design is also particularly advantageous for meeting the axial assembly requirements of the cage. In particular, the cage can be designed to be lightweight, and the support beams can be designed to be particularly lightweight. Therefore, when the cage is installed, when the rolling bodies such as the balls enter the pocket, the clamping claws on the two sides of the pocket elastically deform towards the outer side of the pocket along the circumferential direction, and the supporting beams and the clamping claws can also deform outwards along the radial direction, so that the rolling bodies can enter the pocket conveniently, and the cage has better installation performance. In this case, the opening formed by the two catches of each pocket can also be made smaller than in the prior art designs, owing to the good elasticity of the cage in the radial direction, thus providing better axial retention capability.

Particularly advantageously, the distance of the inner circumferential surface of the catch from the center axis of the cage is greater than or equal to the pitch circle radius of the cage. The guidance of the cage is thereby effected only by the outer limiting points and not by the inner limiting points. Compared with the existing retainer scheme, the whole contact area of the retainer and the rolling body is smaller, the friction force is smaller, and the whole efficiency of the bearing is improved. Furthermore, this makes it possible, on the one hand, to achieve better installation performance as described above, and, on the other hand, to reduce the weight of the cage while ensuring sufficient support.

The above-mentioned object is also achieved by a rolling bearing. The rolling bearing comprises a cage having the above-mentioned features. The rolling bearing can be designed in particular as a ball bearing.

Through the structural design and material selection of the retainer according to the scheme of the invention, the structure of the retainer is further lightened on the premise of meeting the strength requirement, and compared with the design of the current high-speed retainer, the weight is reduced by about 36 percent, so that the centrifugal force of the retainer under the working condition of high rotating speed is obviously reduced, and the high-speed performance of the retainer is obviously improved. Meanwhile, the weight of the retainer is reduced, the consumption of raw materials is less, and the cost advantage is better. In addition, only the inner limiting position or the outer limiting position is arranged, so that the contact area between the retainer and the rolling body is smaller, the friction force is smaller, and the overall efficiency of the bearing is improved. Furthermore, due to the light and thin design of the cage according to the invention, the cage has better elasticity and therefore better assembly properties. In addition, the retainer according to the invention can adopt a similar mold scheme with the current retainer, the mold scheme is less changed, and the cost advantage is also provided in design.

Drawings

A preferred embodiment of the invention is schematically illustrated in the following with reference to the accompanying drawings. The attached drawings are as follows:

fig. 1 is a perspective, partially sectional view of a rolling bearing according to a preferred embodiment;

fig. 2 is a perspective view of the cage according to fig. 1;

fig. 3 is a perspective view of the cage according to fig. 1, viewed from a different perspective than fig. 2;

fig. 4 is a partial sectional view of the cage according to fig. 1; and

fig. 5 is a perspective partial sectional view of the cage according to fig. 1.

Detailed Description

Fig. 1 shows a perspective, partially sectional view of a rolling bearing according to a preferred embodiment. As shown in fig. 1, the rolling bearing includes an outer ring 2 and an inner ring 1 which are coaxially arranged, and a row of rolling bodies 3 arranged between the outer ring 2 and the inner ring 1. The rolling bodies are embodied here as balls 3. The rolling bearing further comprises a cage 4 integrally made of nylon material to isolate the balls 3 and guide the balls 3.

The cage 4 according to the present embodiment is illustrated by fig. 2 to 5.

Fig. 2 and 3 show perspective views of the cage, each viewed from a different perspective. As shown in the drawing, the cage 4 has a cage ring 41 and a cage bar projecting from one axial end face of the cage ring 41, the cage bar here having a substantially flat configuration and extending substantially in the axial direction of the bearing. A pocket 43 for accommodating the balls 3 and restricting the axial displacement of the cage 4 is formed between two adjacent cage beams.

Each of the retainer beams includes a support beam 44 extending from the retainer ring 41 and a catch 42 extending from an end of the support beam 44 at least partially toward both circumferential sides. It will be understood that the support beam 44 connects the two catches 42 and the holder ring 41 belonging to the two pockets, respectively. In the present embodiment, the support beam 44 extends from the holder ring 41 obliquely to the axial direction toward the radially inner side in an arc shape, and the arc structure avoids stress concentration. The catches 42 in this case extend substantially at the same radial level.

The opening formed by the two catches 42 of the same pocket 43 is designed here such that the opening is smaller than the diameter of the ball 3 while ensuring assembly. Whereby the two catches 42 and the holder ring 41 together fulfill an axial stop function.

In the rolling body circumferential support region of the cage bar, a reinforcement 48 is formed, which thickens the cage bar in the radial direction. The bead 48 is configured radially inward of the cage beam. The rolling element circumferential support surface 45, which is formed by the support beams 44, the catches 42 and the reinforcing ribs 48, is spherical, thereby matching the structure of the ball 3.

Fig. 4 shows a partial section through the cage according to fig. 1, and fig. 5 shows a three-dimensional partial section through the cage according to fig. 1. Fig. 4 and 5 show the structure of the reinforcing bead in an enlarged manner. The reinforcing rib 48 comprises two arc-shaped sections which extend from the free ends of the two catches 42 along the contour of the rolling element circumferential support surface 45 in each case toward the cage ring 41, and a connecting section which connects the two arc-shaped sections in the circumferential direction. The two arc segments do not extend to the cage ring 41, but end in a substantially axial middle section of the arc-shaped support beam 44. In other embodiments, the arcuate section of the reinforcing bar may also originate from the middle section of the grab, i.e. not from the free end of the grab.

The strength of the cage beams, in particular the circumferential support regions of the cage beams, can thus advantageously be ensured and the balls 3 provided with circumferential support surfaces 45 by the stiffening webs 48 on each cage beam, which are of H-shaped design. The support beams 44 are designed to be thin, i.e. with a small thickness in the radial direction, and the cage 4 has a better elasticity. Therefore, when the cage 4 is installed, when the balls 3 enter the pocket 43, the support beam 44 and the catches 42 can also deform radially inward while the catches 42 on both sides of the pocket 43 elastically deform outward of the pocket in the circumferential direction, thereby facilitating the entry of the balls 3 into the pocket 43 and providing better installation performance. In addition, compared with the existing retainer scheme, the whole contact area of the retainer 4 and the balls 3 is smaller, the friction force is smaller, and the whole efficiency of the bearing is improved. The distance of the outer peripheral surface 46 of the catch 42 from the center axis of the cage 4 is smaller than or equal to the pitch circle radius of the cage 4. The guidance of the cage 4 is thereby effected only by the inner limiting points and not by the outer limiting points. This makes it possible, on the one hand, to achieve better installation performance as described above and, on the other hand, to reduce the weight of the cage while ensuring sufficient support. Through the structural design and material selection of the retainer according to the scheme of the invention, on the premise of meeting the strength requirement, the structure of the retainer is further lightened, so that the centrifugal force of the retainer under the working condition of high rotating speed is obviously reduced, and the high-speed performance of the retainer is obviously improved.

Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.

List of reference numerals

1 inner ring

2 outer ring

3 rolling element

4 holding rack

41 cage ring

42 grab

43 pocket

44 support beam

45 circumferential support surface for rolling body

46 outer peripheral surface of the gripper

47 inner peripheral surface of the chuck

48 reinforcing ribs

Claims

1. Cage for a rolling bearing, having a cage ring (41) and cage webs projecting from at least one axial end face of the cage ring (41), wherein pockets (43) for receiving rolling bodies (3) of the rolling bearing are formed between two adjacent cage webs, characterized in that,

each of the cage bars having a support beam (44) extending from the cage ring (41) and a catch (42) extending from the end of the support beam (44) at least partially on both sides in the circumferential direction,

wherein a reinforcing rib (48) thickening the cage bar in the radial direction is formed in the rolling body circumferential support region of the cage bar.

2. Cage according to claim 1, characterized in that the cage (4) is a nylon cage.

3. Cage according to claim 1, characterized in that the rolling element circumferential support surface (45) formed by the support beam (44), the catch (42) and the reinforcement rib (48) is spherical.

4. Cage according to claim 3, characterized in that the reinforcing ribs (48) comprise two arc-shaped sections which extend from the two catches (42) respectively along the contour of the rolling element circumferential support surface (45) towards the cage ring (41) and a connecting section which connects the two arc-shaped sections in the circumferential direction.

5. Cage according to claim 3, characterized in that the support beams (44) extend arcuately obliquely to the axial direction and the catches (42) extend at the same radial height.

6. Cage according to claim 5, characterized in that the supporting beams (44) extend obliquely to the axial direction from the cage ring (41) towards the radial inside, the reinforcing ribs (48) being configured radially inside the cage beams.

7. Cage according to claim 6, characterized in that the distance of the outer circumferential surface (46) of the catch (42) from the central axis of the cage (4) is smaller than or equal to the pitch circle radius of the cage (4).

8. Cage according to claim 5, characterized in that the supporting beams (44) extend obliquely to the axial direction from the cage ring (41) towards the radial outside, the reinforcing ribs being configured radially outside the cage beams.

9. The cage of claim 8, wherein the distance of the inner peripheral surface of the catch relative to the central axis of the cage is greater than or equal to the pitch circle radius of the cage.

10. Rolling bearing, characterized in that it comprises a cage according to any one of the preceding claims.