Cage for rolling bearing

Abstract

[Cage for rolling bearing] The cage 18 for rolling bearing is intended to ensure the circumferential spacing of at least one row of balls and comprises a plurality of cells 24 for the balls of said row. The cage comprises an annular heel 20 and separation portions 22 extending from the heel and delimiting between them said cells. The cage further comprises at least one reinforcing ring 25 which is embedded at least partly inside the heel 20 and which extends, inside said cage, only in the heel. Reference: Figure 4

Description

Title of the invention: Cage for rolling bearing Technical field of the invention

[0001] The present invention relates to the field of rolling bearing cages intended to ensure the circumferential spacing of at least one row of balls, and in particular cages intended for applications at high rotational speeds. State of the prior art

[0002] Conventionally, a cage comprises an annular heel and separation portions extending from the heel and delimiting between them cells for housing the balls. The separation portions are generally provided with claws to delimit the cells and to ensure the retention of the cage on the balls. For more details on the design of such a cage, one can for example refer to patent FR-B1-2 911 934.

[0003] For reasons of cost and weight, this type of cage is generally made of synthetic material.

[0004] In applications with high rotational speeds or high temperatures, deformations of the cage may occur which cause contact with the bearing rings and / or an enlargement of the size of the cells, which may lead to the balls separating from the cage.

[0005] To overcome these drawbacks, one solution is to increase the thickness of the heel of the cage. However, this may be incompatible with the specifications of the specifications of certain applications.

[0006] Another solution is to reduce the separation portions of the cage to the radial dimension so that these portions are less sensitive to centrifugal effects. However, this can result in loss of the balls.

[0007] The present invention aims to remedy these drawbacks. Summary of the invention

[0008] The invention relates to a rolling bearing cage intended to ensure the circumferential spacing of at least one row of balls and comprising a plurality of cells for the balls of said row.

[0009] The cage comprises an annular heel and separating portions extending from the heel and delimiting between them said cells.

[0010] According to a general characteristic, the cage further comprises at least one reinforcing ring which is embedded at least partly inside the heel and which extends, inside said cage, entirely into the heel.

[0011] The reinforcement ring makes it possible to increase the mechanical resistance of the cage. The reinforcement ring only stiffens the cage when it deforms.

[0012] The reinforcing ring makes it possible to limit deformations of the cage in applications of the cage at high rotational speeds or at high temperatures. By stiffening the cage, the reinforcing ring also allows for better responsiveness during significant accelerations.

[0013] Preferably, the heel is provided with a first front face and a second opposite front face from which the separation portions extend. The first and second front faces axially delimit the axial thickness of the heel. Said reinforcing ring is entirely located, inside said cage, between the first and second front faces.

[0014] In one embodiment, the cage comprises a plurality of recesses spaced apart from each other in the circumferential direction. Each recess may extend into the thickness of one of the separating portions and be open radially on the inner side. The recesses may extend from the first front face of the heel.

[0015] The recesses can be used to ensure the centering of the reinforcement ring in the associated manufacturing mold. The recesses also make it possible to obtain a substantially constant thickness of the cage.

[0016] Said reinforcing ring may be flush with the bottom of each recess. Alternatively, said reinforcing ring may remain radially spaced from the bottom of each recess.

[0017] In one embodiment, the reinforcing ring is open at a point on its circumference. The reinforcing ring is thus provided with first and second opposite ends, delimiting the ring in the circumferential direction and which are spaced from each other.

[0018] The opening may be located circumferentially in the area of ​​one of the separating portions. Alternatively, the opening may be located circumferentially between two successive separating portions.

[0019] Alternatively, the first and second ends of the ring could bear against each other.

[0020] In another variant, the reinforcing ring could be annular, i.e. continuous in the circumferential direction.

[0021] Said reinforcement ring may have a square, rectangular or circular profile in cross section.

[0022] Preferably, the heel and the separation portions of the cage are made in a single piece by molding at least one synthetic material.

[0023] Said reinforcing ring may have, on its outer surface, hollow elements, for example grooves and / or striations, for attaching the heel thereto.

[0024] The invention also relates to a bearing comprising an inner ring, an outer ring, at least one row of balls arranged between said rings and a cage as defined previously. Brief description of the figures

[0025] The present invention will be better understood upon studying the detailed description of the embodiment, taken as a non-limiting example and illustrated by the appended drawings in which:

[0026] [Fig-1] is a partial perspective view of a rolling bearing according to an exemplary embodiment of the invention,

[0027] [Fig.2] is a perspective view of the bearing cage of [Fig. 1],

[0028] [Fig.3] is a front view of the cage of [Fig.2],

[0029] [Fig.4] is a sectional view along axis IV-IV of [Fig.3], and

[0030] [Fig.5]

[0031] [Fig.6]

[0032] [Fig.7]

[0033] [Fig.8] are sectional views of cages for rolling bearings according to other exemplary embodiments of the invention. Detailed description of the invention

[0034] As can be seen in [Fig. 1], the rolling bearing 10 comprises an outer ring 12, an inner ring 14, a plurality of balls 16 arranged radially between the rings and a cage 18 for maintaining the regular circumferential spacing of the balls. The outer ring 12 and inner ring 14 are here solid. The term "solid ring" means a ring whose shape is obtained by machining with chip removal (turning, grinding) from tubes, bars, forged and / or rolled blanks.

[0035] As illustrated more visibly in Figures 2 and 3, the cage 18 comprises an annular axial portion or heel 20 intended to be arranged axially on one side of the balls, and fingers or separation portions 22 extending axially from the heel 20 and spaced apart from each other in the circumferential direction. The separation portions 22 delimit between them cells 24 in which the balls are arranged. Each cell 24 is delimited in the circumferential direction by two successive separation portions 22. Each cell 24 is open radially inwards and outwards and also open axially on the side opposite the heel 20. The separation portions 22 and the cells 24 are here respectively identical to each other.

[0036] The heel 20 and the separation portions 22 of the cage are advantageously made in a single piece by molding a synthetic material, such as for example polyamide, in particular PA 66 or PA 46, or a polyetheretherketone (PEEK).

[0037] As will be described in more detail below, the cage 18, with axis 18a, also comprises a reinforcing ring 25 partially embedded inside the heel 20. The reinforcing ring 25 can be made of metallic material, for example steel, or aluminum, or an alloy, or can also be made of rigid synthetic material.

[0038] Referring now to [Fig.4], the heel 20 of the cage is provided with a first front face 20a and a second opposite front face 20b delimiting the axial thickness of said heel. The front faces 20a, 20b here extend radially.

[0039] The separation portions 22 of the cage extend axially from the front face 20b of the heel on the side opposite the front face 20a. The separation portions 22 are in the form of pins projecting axially relative to the heel 20. Each separation portion 22 is delimited radially by an inner surface aligned with the bore of the heel 20.

[0040] Each separation portion 22 has, on each side in the circumferential direction, a spherical wall connecting to the spherical wall of the adjacent separation portion 22 to form the associated cell 24.

[0041] Each separation portion 22 comprises two claws 26 extending axially opposite the heel 20 and extending circumferentially in opposite directions. The claws 26 of each separation portion 22 each axially and circumferentially extend one of the spherical walls of said separation portion. For a given cell 24, the spherical walls and the claws 26 of the separation portions 22 tend to envelop the associated ball.

[0042] Each claw 26 extends towards the claw 26 of the adjacent separation portion 22 to delimit the associated cell 24. The free ends of the two adjacent claws 26 of two adjacent separation portions 22 are spaced apart by a distance less than the diameter of the associated ball. The claws 26 are capable of ensuring the axial retention of the cage 18 by snap-fastening onto the ball disposed in the associated cell 24. The cage 18 is retained axially on the balls by the claws 26. The claws 26 of each separation portion 22 are separated in the circumferential direction by a recess 28 so that they each have a relatively small circumferential thickness and a certain flexibility allowing the cage 18 to be snap-fastened onto the rolling elements.

[0043] The cage 18 also comprising a plurality of recesses 30 spaced apart from each other in the circumferential direction, here in a regular manner. Each recess 30 extends in the radial thickness of one of the separation portions 22 and is open radially on the inner side. Each recess 30 extends radially from the inner surface of the associated separation portion 22. Each recess 30 extends axially from the front face 20a of the heel to the associated separation portion 22 while remaining axially at a distance from the recess 28. Each recess 30 has a generally rectangular shape.

[0044] As indicated previously, the cage 18 also comprises the reinforcing ring 25 partially embedded inside the heel 20. The reinforcing ring 25 is coaxial with the axis 18a of the cage. Inside the cage 18, the reinforcing ring 25 extends only in the heel 20. In other words, inside the cage 18, the reinforcing ring 25 does not extend inside the separation portions 22. Inside the cage 18, the reinforcing ring 25 is entirely located between the front faces 20a, 20b of the heel considering the axial direction.

[0045] As can be seen in particular in [Fig. 2], the reinforcing ring 25 is open here at a point on its circumference. The reinforcing ring 25 is provided with first and second opposite ends and delimiting the ring in the circumferential direction. The opening of the reinforcing ring 25 is located circumferentially in the area of ​​one of the separation portions 22. The opening of the reinforcing ring 25 is thus located in the axial extension of this separation portion 22.

[0046] Referring again to [Fig. 4], the reinforcing ring 25 is provided with a first front face 25a and a second opposite front face 25b delimiting the axial thickness of said ring. The front faces 25a, 25b here extend radially. In the illustrated embodiment, the reinforcing ring 25 is flush with the front face 20a of the heel. The front face 25a of the reinforcing ring is flush with this front face 20a. The remainder of the reinforcing ring 25 is embedded inside the heel 20.

[0047] Alternatively, it is possible to provide other arrangements of the reinforcing ring 25 inside the heel 20 of the cage.

[0048] For example, the front face 25a of the reinforcing ring could be embedded inside the heel 20 and the bore of said ring could be flush with the bottom of each recess 30.

[0049] Another possible arrangement is illustrated in [Fig.5] which differs from the first example illustrated only in that the reinforcing ring 25 is located in the center of the heel 20 of the cage considering the radial direction.

[0050] Yet another possible arrangement is illustrated in [Fig.6] which differs from the first example illustrated only in that the outer surface of the reinforcing ring 25 is flush with the outer surface of the heel 20 of the cage.

[0051] In the embodiment illustrated in [Fig.7], the reinforcing ring 25 is flush with the bottom of each cell 24. More precisely, the front face 25b of the reinforcing ring is flush with the bottom of each cell 24.

[0052] In the embodiments illustrated above, the reinforcement ring 25 has a square profile in cross section. Alternatively, the reinforcement ring 25 may present other profiles, for example a triangular, rectangular or even circular profile as illustrated in [Fig.8].

[0053] In the embodiments described above, the reinforcing ring 25 is embedded only partially inside the heel 20. This facilitates the positioning and holding of the reinforcing ring 25 inside the associated manufacturing mold before overmolding of the synthetic material of the heel 20 and the separation portions 22.

[0054] As a variant, it remains possible to provide that the reinforcing ring 25 is entirely embedded inside the heel 20.

[0055] In the illustrated embodiments, a single reinforcing ring 25 is embedded inside the heel 20. Alternatively, it could be possible to provide several reinforcing rings embedded inside the heel 20.

[0056] In the illustrated embodiments, the reinforcing ring 25 is in the form of a flat ring. Alternatively, the reinforcing ring could comprise undulations in the radial direction and / or in the axial direction. In another variant, the reinforcing ring could be in the form of a winding of turns.

Claims

Claims

1. Cage (18) for a rolling bearing intended to ensure the circumferential spacing of at least one row of balls and comprising a plurality of cells (24) for the balls of said row, the cage comprising an annular heel (20) and separation portions (22) extending from the heel and delimiting between them said cells, characterized in that it further comprises at least one reinforcing ring (25) which is embedded at least partly inside the heel (20) and which extends, inside said cage, only in the heel.

2. Cage according to claim 1, in which the heel (20) is provided with a first front face (20a) and a second opposite front face (20b) from which the separation portions (22) extend, the first and second front faces (20a, 20b) axially delimiting the axial thickness of the heel, and said reinforcing ring (25) being entirely located, inside said cage, between the first and second front faces (20a, 20b).

3. Cage according to claim 2, in which said reinforcing ring (25) is flush with the first front face (20a) of the heel.

4. A cage according to any preceding claim, comprising a plurality of recesses (30) spaced apart from each other in the circumferential direction, each recess (30) extending within the thickness of one of the separating portions (22) and being radially open on the inner side.

5. A cage according to claim 4 dependent on claim 2 or 3, wherein the recesses (30) extend from the first front face (20a) of the heel.

6. Cage according to claim 4 or 5, in which said reinforcing ring (25) is flush with the bottom of each recess (30).

7. Cage according to any one of the preceding claims, in which said reinforcing ring (25) is made of metallic material.

8. A cage according to any preceding claim, wherein said reinforcing ring (25) is open at a point on its circumference, the opening being located circumferentially in the area of one of the separating portions ().

9. Cage according to any one of the preceding claims, in which said reinforcing ring (25) has a square, or rectangular or circular profile in cross section.

10. Rolling bearing comprising an inner ring (12), an outer ring (14), at least one row of balls (16) arranged between said rings and a cage (18) according to any one of the preceding claims.

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