Bearing cages and bearings

Abstract

To provide a bearing cage and a bearing.SOLUTION: A bearing cage comprises: an annular base portion having a front side and a back side at an opposite side; and a plurality of cantilever portions as the plurality of cantilever portions extending from the front side of the base portion in an axial front direction of the bearing cage, arranged along a circumference of the annular base portion, and defining a plurality of pockets for housing rolling elements of the bearing. The base portion has a radial thickness larger than a radial thickness of the plurality of cantilever portions. Each of the plurality of cantilever portions comprises two projection portions and a connection portion between two projection portions. The bearing cage includes a plurality of recessed portions formed at a radial outer side of the cantilever portions in a manner that each of the recessed portions is formed by the connection portion recessed from the corresponding two projection portions, and the recessed portion further includes a recessed portion opened at an axial front side of the bearing cage, and a plurality of grooves formed at a radial inner side of the bearing cage.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure generally relates to a cage for a ball bearing and a ball bearing including such a cage. The present disclosure also relates to a one-way snap-in bearing cage and a deep groove ball bearing including such a bearing cage, particularly a bearing cage and a bearing suitable for high-speed rotation. [Background technology]

[0002] Ball bearings, especially deep groove ball bearings, are widely used due to their low rotational friction and high rotational speed performance. One-way snap-in cages have the advantages of low cost and easy installation, and are therefore commonly used with ball bearings, especially deep groove ball bearings.

[0003] A standard one-way snap-in cage includes a generally annular base and a plurality of cantilever sections extending axially from one side of the base, the cantilever sections being spaced apart around the circumference of the base to form a plurality of pockets for receiving the rolling elements of the bearing. Summary of the Invention [Problem to be solved by the invention]

[0004] Prior art one-way snap-in cages have the following drawbacks: as rotational speed increases, the cantilevered sections deflect radially outward, resulting in increased centrifugal force and the so-called umbrella effect, which deteriorates the fit between the pockets and the rolling elements and increases friction between the cage and the rolling elements, resulting in bearing degradation and / or failure.

[0005] Proper lubrication is crucial to high performance bearings, and too much or not enough grease can degrade bearing performance.

[0006] There is a constant need to reduce the parasol effect and improve bearing lubrication. [Means for solving the problem]

[0007] According to an aspect of the disclosure, there is provided a bearing cage for a ball bearing, the bearing cage comprising: a generally annular base having a front side and an opposite rear side; and a plurality of cantilever sections extending from the front side of the base in an axial forward direction of the bearing cage, the cantilever sections being arranged around the circumference of the annular base to form a plurality of pockets for accommodating rolling elements of the bearing, the base having a radial thickness greater than that of the plurality of cantilever sections, each of the plurality of cantilever sections comprising two protrusions and a connection between the two protrusions, the bearing cage further comprising at least one of the following: a recess open to the axial front side of the bearing cage; and a plurality of grooves formed in the radial inner side of the bearing cage.

[0008] In some embodiments of the present disclosure, the trunk portion has an outer diameter that is greater than the outer diameter of the plurality of cantilever portions.

[0009] In some embodiments of the present disclosure, the two protrusions have a radial thickness greater than the radial thickness of the connecting portion, and the protrusions extend beyond the connecting portion in the axial forward direction.

[0010] In some embodiments of the present disclosure, the connecting portion comprises a first segment adjacent to the trunk portion and extending at an angle to the axis of the bearing cage, and a second segment away from the trunk portion and generally parallel to the axis of the bearing cage.

[0011] In some embodiments of the present disclosure, each of the protrusions includes a contact surface forming a pocket and a curved surface facing away from the contact surface, and the recess is formed by the radially outer surface and the curved surface of the connecting portion.

[0012] In some embodiments of the present disclosure, each of the plurality of grooves is disposed between two circumferentially adjacent pockets.

[0013] In some embodiments of the present disclosure, each of the plurality of grooves is arranged in a one-to-one relationship with the plurality of cantilever portions, and each of the plurality of grooves is centrally located between two adjacent pockets in the circumferential direction.

[0014] In some embodiments of the present disclosure, each of the grooves extends to and forms a portion of the rear side of the annular stem, and each of the grooves comprises a first segment adjacent the rear side of the annular stem and a second segment that slopes away from the rear side of the annular stem, the first segment having a constant radial depth and the sloped second segment having a depth that decreases in a direction away from the rear side of the annular stem.

[0015] In some embodiments of the present disclosure, each of the grooves has a generally trapezoidal or rectangular shape with a bottom side posterior to the stem and a top side distal to the stem's posterior side; where: PI*dc / (Z*4)≦L2≦PI*dc / (Z*2) L1≦L2 where L1 is the length of the top side of the trapezoidal shape, L2 is the length of the base side of the trapezoidal shape, dc is the inner diameter of the bearing cage, and Z is the number of rolling elements in the bearing.

[0016] Some embodiments of the present disclosure include a chamfer formed on the face of the protrusion opposite the pocket formed by the protrusion.

[0017] In some embodiments of the present disclosure, the cantilever portion of the bearing cage further comprises an axial protrusion formed on the radially outer surface of the connection portion.

[0018] According to another aspect of the present disclosure, there is provided a ball bearing comprising an inner ring, an outer ring, a plurality of rolling elements disposed between the inner ring and the outer ring, and a bearing cage as defined in any one of the preceding claims, wherein the bearing cage is disposed between the inner ring and the outer ring, and each of the plurality of rolling elements is received in one of the plurality of pockets.

[0019] In some embodiments of the present disclosure, the inner ring includes, in its outer diameter surface, raceways for receiving a plurality of rolling elements and at least one circumferential groove, one of which at least partially overlaps with the groove in the axial direction of the ball bearing.

[0020] In some embodiments of the present disclosure, the inner ring includes two circumferential grooves in the outer diameter surface of the inner ring, and the raceway is disposed between the two circumferential grooves.

[0021] In some embodiments of the present disclosure, a portion of the groove extends above the raceway and has an axial dimension of L3, and a bottom of the groove is spaced from the outer diameter surface by a distance L4; where: L3>0 L4 / Dw>0.08, preferably L4 / Dw>0.12, most preferably L4 / Dw>0.16 and Dw is the diameter of the rolling element.

[0022] Other systems, methods, features, and advantages of the present disclosure will be, or become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the disclosure, and be protected by the following claims.

[0023] The disclosure can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the present disclosure. Moreover, in the figures, like reference numerals, corresponding parts are shown through different views. [Brief explanation of the drawings]

[0024] [Figure 1A] FIG. 1 is a perspective view of a bearing cage according to some embodiments of the present disclosure. [Figure 1B] 1B is a perspective view of the bearing cage of FIG. 1A from a different perspective. FIG. [Figure 1C] 1B is a perspective view of the bearing cage of FIG. 1A from a different perspective. FIG. [Figure 2] FIG. 1B is a rear view of the bearing cage of FIG. 1A. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along line BB in FIG. 2. [Figure 5] 3 is a cross-sectional view taken along line CC in FIG. 2. FIG. [Figure 6] FIG. 1 shows a cross section of a ball bearing with a bearing cage. [Figure 7] FIG. 7 is an enlarged view of the circled portion of FIG. 6. [Figure 8] FIG. 10 is a perspective view of a bearing cage according to another embodiment of the present disclosure. [Figure 9A] FIG. 10 is a perspective view of a bearing cage according to yet another embodiment of the present disclosure. [Figure 9B] FIG. 10 is a perspective view of a bearing cage according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In the following description of the present disclosure, detailed descriptions of known functions and configurations integrated herein will be omitted if it may significantly obscure the subject matter of the present disclosure.

[0026] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. As used herein, the terms "comprises," "comprising," "includes," and / or "including" identify the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the terms "and / or" and the " / " symbol mean the inclusion of one or more combinations of any or all of the associated listed items. In addition, terms such as "first," "second," etc. may be used herein to describe various elements, components, steps, or calculations; these elements, components, steps, or calculations should not be limited to these terms; rather, these terms are used only to distinguish between single elements, components, steps, or calculations. For example, a first part may be referred to as a second part, a first calculation may be referred to as a second calculation, and a first step may be referred to as a second step, all without departing from the scope of the present disclosure.

[0027] As used herein, the terms "axis", "central axis", "axis of rotation" refer to the axis about which the bearing rotates, "radius", "radially", "radially" and equivalent terms refer to the direction from the centre or axis to the periphery of the bearing cage or bearing, "axial", "axially", "axially" and equivalent terms refer to the direction along the axis of the bearing or cage, i.e. radially or perpendicular to the periphery of the bearing or bearing cage, and "forward", "forwardly", "forwardly" refer to the axial direction pointed by the cantilevered portion of the bearing cage or the axial direction in which the cantilevered portion extends from the stem.

[0028] To clarify and thereby inform the public about the use in the current claims, "at least one 、 , ···, and <n> " or "At least one< / n> 、 、···、 <n>The phrases "A, B, ..., or combinations thereof" are defined by the applicant in the broadest sense and supersede any other implied definition, either earlier or later, unless expressly claimed by the applicant. These phrases mean one or more elements selected from the group including A, B, ..., and N, i.e., any combination of one or more of A, B, ..., or N, including any one element alone or in combination with one or more of the other elements, which may also, in combination, include additional, unlisted elements.

[0029] Figures 1A-1C are perspective views of a bearing cage 100 according to some embodiments of the present disclosure. Figure 2 is a rear view of the bearing cage 100 of Figure 1A, Figure 3 is a cross-sectional view taken along line AA in Figure 2, Figure 4 is a cross-sectional view taken along line BB in Figure 2, and Figure 5 is a cross-sectional view taken along line CC in Figure 2.

[0030] As shown, bearing cage 100 includes a generally annular trunk 110 having a front side 114 and a rear side 116 opposite front side 114, and a plurality of cantilever sections 130 extending from trunk front side 114 in the axial forward direction of bearing cage 100. As shown in Figures 1A-1C, the plurality of cantilever sections 130 are preferably equally spaced from one another around the circumference of annular trunk 110.

[0031] As shown in Figures 1A-1C and 5, each cantilever portion 130 includes two protrusions 132a, 132b and a connecting portion 142 that connects the two protrusions 132a, 132b together. Each protrusion 132a, 132b includes a contact surface 133a, 133b and a curved surface 135a, 135b that faces away from the contact surface 133a, 133b. Each contact surface 133a, 133b of protrusions 132a, 132b of one cantilever portion 130 faces the contact surface 133a, 133b of protrusion 132a, 132b of the adjacent cantilever portion 130. The two facing contact surfaces 133a, 133b form a pocket 134 therebetween. Each pocket 134 serves to receive a rolling ball of the bearing, and the contact surfaces forming the pocket 134 contact the rolling balls received in the pocket. Each connecting portion 142 is radially recessed from the two protrusions (i.e., the radially outer surface of the connecting portion 142 has a shorter radial distance from the axis of the bearing cage than the radially outer surfaces of the two protrusions 132a, 132b), forming a recess 144 on the radially outer side of the cantilevered portion 130. The recess 144 is formed by the radially outer surface of the connecting portion 142 and the curved surfaces 135a, 135b of the cantilevered portion 130 and is open axially forward or from the axially front side, as best seen in FIGS. 1A and 4.

[0032] The recess 144 provides additional space for storing grease when there is excess grease in the bearing and allows grease to be replenished to the raceway when there is insufficient grease in the raceway. When the bearing rotates, grease may flow into the recess 144 from other parts of the bearing, such as the inner raceway or the outer raceway, and the more grease there is in the bearing, the more likely the grease will flow into the recess 144. Some of the grease that flows into the recess 144 may be temporarily retained within the recess 144. A dynamic equilibrium exists between the flow of grease into and out of the recess 144, and when the dynamic equilibrium is reached, the more grease there is in the bearing, the more grease there will be in the recess 144. Thus, the recess 144 can store grease when there is excess grease in the bearing and allow grease to be replenished to the bearing raceway when there is insufficient grease in the bearing raceway. The recess 144 can reduce or eliminate technical problems associated with excess grease. For example, recesses 144 can reduce heat generated during acceleration and deceleration of the bearing, which results from strong shear between the grease and rolling components such as balls and bearings. That is, recesses 144 reduce or eliminate heat generated by grease agitation.

[0033] 1A-1C, 3, and 4, trunk portion 110 has a radial thickness T1 that is greater than the radial thickness of cantilevered portion 130. The radially inner surface of trunk portion 110 and the radially inner surface of cantilevered portion 130 have the same radial distance from the axis of the bearing cage, such that they share a common radially inner surface 102. The radially outer surface of trunk portion 110 has a greater radial distance from the axis of the bearing cage than that of cantilevered portion 130.

[0034] The two protrusions 132a, 132b in the cantilever portion 130 have a radial thickness T2 that is significantly greater than the radial thickness T3 of the connecting portion 142. In addition, the protrusions 132a, 132b have a larger axial dimension such that the protrusions extend axially beyond the connecting portion 142, as shown in Figures 1A-1C, 4 and 5.

[0035] The smaller radial distance from the axis of the bearing cage to the radially outer surface of cantilevered portion 130, i.e., the smaller outer diameter of cantilevered portion 130, and the reduced material due to the presence of recess 144, result in a reduction in centrifugal force acting on cantilevered portion 130. Thus, the bearing cage has the technical advantage of reducing radially outward deflection, i.e., it can reduce or suppress the so-called parasol effect. The presence of curved surfaces 135a, 135b can further reduce the material of cantilevered portion 130, thereby further reducing or suppressing the so-called parasol effect.

[0036] In some embodiments of the present disclosure, the annular backbone 110 has an increased radial thickness T1, which increases the structural strength of the bearing cage. Additionally, as described herein, the cantilevered section configuration results in a reduction in centrifugal forces acting on the cantilevered section 130. Therefore, cage deformation, or the so-called parasol effect, can be significantly reduced or suppressed by the increased radial thickness T1 and the configuration of the cantilevered section 130.

[0037] As shown in Figures 1A-1C and 2-5, the bearing cage 100 includes a plurality of grooves 112 formed on the radially inner side 102 of the bearing cage 100. In some embodiments of the present disclosure, the plurality of grooves 112 are provided in a one-to-one relationship with the plurality of cantilever portions 130. That is, there is one groove 112 corresponding to each of the plurality of cantilever portions 130. In some embodiments of the present disclosure, each of the plurality of grooves 112 is centered between two circumferentially adjacent pockets. In some embodiments, each of the plurality of grooves is provided between two circumferentially adjacent pockets.

[0038] As shown in Figures 1A-1C and 2-5, the grooves 112 extend to the rear side 116 of the annular trunk 110, such that the grooves 112 form part of the rear side 116 of the annular trunk. That is, the grooves 112 open from the rear side 116 of the annular trunk. Each groove 112 includes a first segment 112a adjacent the rear side 116 of the annular trunk 110 and a second segment 112b that slopes away from the rear side 116 of the annular trunk 110. As shown in Figure 4, the first segment 112a has a flat bottom, while the second segment 112b has a sloped bottom.

[0039] 1A to 1C and 2 to 5, each groove 112 is circumferentially centered between two adjacent pockets 134 (and thus centered between two adjacent rolling elements 190), and the circumferential dimension of the groove 112 spans most of the circumferential space between the two adjacent rolling elements 190. Because the groove 112 is located between two adjacent pockets 134 (rolling elements 190) and spans most of the space between the two adjacent pockets 134 (rolling elements 190), it provides additional or expanded passages for grease to flow between the two rolling elements 190, facilitating the flow of grease between the two rolling elements, thereby improving the smooth flow of grease in the space between the inner ring and the bearing cage during rotation of the bearing. Furthermore, the grooves 112 can reduce or eliminate technical problems associated with excess grease. For example, grooves 112 can reduce heat generated during bearing acceleration and deceleration, which results from strong shear between the grease and rolling components such as balls and cages. That is, grooves 112 can reduce heat generated by grease agitation. In some embodiments of the present disclosure, the grease loading or total amount is carefully selected or adjusted and / or special greases are used for improved lubrication, thereby reducing heat generated by grease agitation.

[0040] As the bearing rotates, grease may flow from the inner raceway into groove 112, and if there is excess grease in the inner raceway of the bearing, grease may be more likely to flow into the groove. Some of the grease that flows into groove 112 may be temporarily retained in the groove, and some of the grease may flow back to the inner raceway. A dynamic equilibrium of grease flowing into and out of groove 112 exists, and when dynamic equilibrium is reached, the more grease there is in the inner raceway, the more grease there will be in groove 112. That is, if there is excess grease in the inner raceway, groove 112 can provide additional space to store grease. On the other hand, if there is insufficient grease in the raceway, the groove can replenish grease to the raceway.

[0041] In some embodiments of the present disclosure, the annular backbone 110 has an increased radial thickness T1. In some embodiments of the present disclosure, the gap between the annular backbone 110 and the inner ring 170 can be reduced due to the increased radial thickness T1. Although the gap between the annular backbone 110 and the inner ring 170 is reduced, grease in the inner raceway can still flow smoothly due to the presence of the grooves 112 between two adjacent rolling elements 190. That is, the structural strength of the backbone 110 can be improved (due to the increased radial thickness T1) without compromising the lubrication of the bearing.

[0042] In prior art bearing cages, mass distribution and structural strength are non-uniform along the circumference of the bearing cage. Bearing cage segments with cantilevered sections typically contain more material and have higher structural strength than bearing cage segments with pockets. Compared to prior art bearing cages, the bearing cage of the present disclosure has less material in the bearing cage segments with cantilevered sections due to the presence of grooves 112 and / or recesses 142. Thus, the bearing cage of the present disclosure has a more uniform mass and strength distribution along the circumference of the bearing cage.

[0043] As previously mentioned, the bearing cage 100 has an increased overall structural strength, which reduces the parasol effect of the bearing cage structure under high speed rotation. In the prior art, if the bearing cage had increased structural strength to suppress or reduce the parasol effect, the protrusions would tend to crack when the cage was installed. Therefore, prior art bearing cages cannot have excessively strong structural strength, which reduces the risk of protrusion cracking.

[0044] The inventors of the present disclosure have found that the presence of grooves 112 can reduce the risk of cracks occurring during cage installation. In particular, as shown in Figure 5, the minimum distance S between grooves 112 and contact surfaces 133a, 133b is a crucial factor that can affect the risk of cage cracks occurring, and an optimal distance S can significantly reduce the risk of cage cracks occurring during cage installation. That is, the bearing cage of the present disclosure can have increased structural strength for suppressing or reducing the parasol effect, while the risk of cracks occurring during cage installation remains reduced.

[0045] Furthermore, the dimensions associated with the groove 112, i.e., L1 and L2 shown in FIG. 5 and L3 and L4 shown in FIG. 7, can be carefully selected or optimized to provide the aforementioned optimal or best technical effects associated with the groove 112. As shown in FIG. 5, the groove 112 has an overall trapezoidal shape when viewed radially. The overall trapezoidal shape includes a base at the rear side 116 of the trunk 110 and an upper side away from the rear side 116 of the trunk 110. The length L1 of the upper side of the trapezoidal shape and the length L2 of the base of the trapezoidal shape are important factors that can affect the technical effects associated with the groove 112. As shown in FIG. 7, the bottom of the first segment 112a of the groove 112 is spaced a distance L4 from the outer diameter surface 173 of the inner ring 170. A portion of the groove 112 extends above the raceway 174 in the outer diameter surface 173 of the inner ring 170 and has an axial dimension L3, i.e., the axial distance between the side of the raceway 174 and the end of the second segment 112b of the groove 112. The distance L4 and the dimension L3 are also important factors that can affect the technical effectiveness of the groove.

[0046] In some embodiments of the present disclosure, L1 and L2 are defined as follows: PI*dc / (Z*4)≦L2≦PI*dc / (Z*2) L1≦L2 where dc is the diameter of the cage bore and Z is the number of rolling elements (rolling balls) in the bearing.

[0047] In some embodiments of the present disclosure, L3 and L4 are defined as follows: L3>0 L4 / Dw>0.08 Here, Dw is the diameter of the rolling element (rolling ball).

[0048] In some further embodiments of the present disclosure, L4 / Dw>0.12. In some still further embodiments of the present disclosure, L4 / Dw>0.16.

[0049] FIG. 6 is a cross-sectional view of a ball bearing 10 including a bearing cage 100. FIG. 7 is an enlarged view of the circled portion of FIG. 6. The ball bearing 10 includes an inner ring 170, an outer ring 160, a plurality of rolling elements 190 disposed between the inner ring 170 and the outer ring 160, and the bearing cage 100. The bearing cage is disposed between the inner ring and the outer ring, and each of the plurality of rolling elements is received in one of a plurality of pockets in the cage. The ball bearing includes a seal member 180 configured to seal the annular space formed between the inner ring 170 and the outer ring 160. The ball bearing has an axis x about which it rotates during operation. The axis x shown in FIG. 6 is also the axis of the bearing cage 100. As best shown in FIG. 7 , the inner ring 170 includes an outer diameter surface 173 and a raceway 174 formed therein, and the outer ring 160 includes an inner diameter surface 163 and a raceway 164 formed therein. The inner ring 170 further includes two circumferential grooves 172a and 172b formed in the outer diameter surface 173 of the inner ring 170. Each of the two circumferential grooves 172a and 172b is located on one side of the raceway 174. Similar to the groove 112 and recess 144 described above, the circumferential grooves 172a and 172b store excess grease and can resupply grease to the bearing raceway if there is insufficient grease in the bearing raceway. As clearly shown in FIG. 7 , the groove 112 has a much larger axial span than the circumferential groove 172a, and the circumferential grooves 172a and 172b are axially disposed within the axial span of the groove 112. In some embodiments, the groove 112 at least partially overlaps with the circumferential groove 172a in the axial direction. With such a configuration, grease stored in the circumferential groove 172a can easily return to the track 174 through the groove 112.

[0050] In some embodiments of the present disclosure, the bearing cage is a one-way snap-in bearing cage and the ball bearing is a deep groove ball bearing.

[0051] 1A-1C and 2-5, the grooves 112 are provided in a one-to-one relationship with the plurality of cantilever portions 130. However, the present disclosure is not so limited, and in some embodiments of the present disclosure, the bearing cage of the present disclosure may not include grooves 112 at all.

[0052] 6 and 7, the bearing of the present disclosure includes two circumferential grooves 172a, 172b in the outer diameter surface 173 of the inner ring 170. However, the present disclosure is not limited thereto, and in some embodiments, the bearing of the present disclosure may include only one circumferential groove or more than two circumferential grooves. In some embodiments, the bearing of the present disclosure may not include any circumferential grooves at all.

[0053] In the illustrated embodiment, both the groove 112 and the recess 142 have a two-segment configuration, however, the present disclosure is not limited thereto and in some embodiments, the groove 112 and / or the recess 142 may include any other suitable configuration, such as a smoothly curved surface.

[0054] In the illustrated embodiment, the cantilevered portions are preferably equally spaced apart from one another around the circumference of the annular backbone. However, the present disclosure is not limited thereto and may include any other suitable configuration. In some embodiments, the cantilevered portions are spaced apart from one another around the circumference of the annular backbone. In some embodiments, the cantilevered portions are arranged around the circumference of the annular backbone.

[0055] FIG. 8 is a perspective view of a bearing cage 200 according to another embodiment of the present disclosure. The bearing cage 200 includes a generally annular backbone 210 and a plurality of cantilevered sections 230. Each cantilevered section 230 includes two protrusions 232a, 232b and a connecting section 242 connecting the two protrusions 232a, 232b together. The bearing cage 200 is similar to the bearing cage 100 shown in FIGS. 1A-1C except for chamfers 238a, 238b formed on the protrusions 232a, 232b. The chamfers 238a, 238b are formed on the faces of the protrusions 232a, 232b opposite the pockets formed by the protrusions. The bearing cage 200 has the technical advantage of reducing the weight of the cantilever portion 230 , whereby the so-called parasol effect can be further reduced or suppressed in the bearing cage 200 .

[0056] 9A and 9B are perspective views of a bearing cage 300 according to yet another embodiment of the present disclosure. The bearing cage 300 includes a generally annular main body 310 and a plurality of cantilever portions 330. Each cantilever 330 includes two protrusions 332a, 332b and a connecting portion 342 that connects the two protrusions 332a, 332b together. The bearing cage 300 is similar to the bearing cage 100 shown in FIGS. 1A to 1C except for the axial protrusion 336 formed on the radially outer surface of the connecting portion 342. The presence of the axial protrusion 336 in the bearing cage 300 provides a technical advantage in that the structural strength of the cantilever portions 330 is improved.

[0057] Systems and methods have been described in general terms to aid in understanding the details of the invention. In some instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of the invention. In other instances, specific details have been given to provide a thorough understanding of the invention. Those skilled in the relevant art will recognize that the invention can be embodied in other specific forms, for example, to adapt to particular systems or devices or situations or materials or components without departing from the spirit or essential characteristics thereof. Therefore, the disclosures and descriptions herein are intended to be illustrative, but not limiting, of the scope of the invention. Therefore, the disclosure should not be limited except in light of the appended claims and their equivalents. [Explanation of symbols]

[0058] 10 Ball bearings 100, 200, 300... Bearing cage 102 Radial inner surface 110, 210, 310... Core 112...Groove 112a First Segment 112b Second Segment 114 Front 116...rear side 130, 230, 330...Cantilever part 132a, 132b, 232a, 232b...Protrusions 133a, 133b...Contact surface 134 Pocket 135a, 135b ··· curved surface 142, 242... Connection 144 recess 160 Outer ring 163 Inner diameter surface 164...orbital 170 Inner ring 172a, 172b...peripheral groove 173...outer diameter surface 174...orbital 180 Seal member 190 Rolling element 238a, 238b Chamfered portion 336...Axial protrusion< / n>

Claims

1. A bearing cage (100, 200, 300) for a ball bearing, comprising: a generally annular trunk (110, 210, 310) having a front side (114) and an opposite rear side (116); a plurality of cantilever portions (130, 230, 330) extending from a front side (114) of the trunk (110, 210, 310) in an axial forward direction of the bearing cage, the cantilever portions (130, 230, 330) being arranged around the circumference of the annular trunk (110, 210, 310) to form a plurality of pockets (134) for receiving the rolling elements (190) of the bearing; Equipped with the trunk portion (110, 210, 310) has a radial thickness greater than the radial thicknesses of the plurality of cantilever portions (130, 230, 330); each of the plurality of cantilever portions (130, 230, 330) comprises two protrusions (132a, 132b, 232a, 232b, 332a, 332b) and a connection portion (142, 242, 342) between the two protrusions (132a, 132b, 232a, 232b, 332a, 332b); The bearing cage (100, 200, 300) has the following features: a plurality of recesses formed on the radially outer side of the cantilever portion (130, 230, 330), each recess being formed by a connection portion recessed from two corresponding protrusions (132a, 132b, 232a, 232b, 332a, 332b), the recesses being open to the axial front side of the bearing cage (100); and a plurality of grooves (112) formed on the radially inner side (102) of the bearing cage (100); and further comprising at least one of The bearing cage (100, 200, 300), wherein the connecting portion (142, 242, 342) comprises a first segment (142a) adjacent to the main body (110, 210, 310) and extending at an angle to the axis of the bearing cage, and a second segment (142b) away from the main body and generally parallel to the axis of the bearing cage.

2. 2. The bearing cage (100, 200, 300) of claim 1, wherein the trunk portion (110, 210, 310) has an outer diameter that is greater than an outer diameter of the plurality of cantilever portions (130, 230, 330).

3. 3. The bearing cage (100, 200, 300) according to claim 1 or 2, wherein the two protrusions (132a, 132b, 232a, 232b, 332a, 332b) have a radial thickness greater than the radial thickness of the connecting portion (142, 242, 342), and the protrusions (132a, 132b, 232a, 232b, 332a, 332b) extend beyond the connecting portion (142, 242, 342) in the axial forward direction.

4. 4. A bearing cage (100, 200, 300) according to any one of claims 1 to 3, wherein each of the protrusions (132a, 132b) comprises a contact surface (133a, 133b) forming the pocket (134) and a curved surface (135a, 135b) facing away from the contact surface (133a, 133b), and the recess (144) is formed by the radially outer surface of the connection portion (142) and the curved surface (135a, 135b).

5. 5. The bearing cage (100, 200, 300) according to claim 1, wherein each of the plurality of grooves (112) is disposed between two adjacent pockets (134) in the circumferential direction.

6. 6. The bearing cage (100, 200, 300) of claim 5, wherein each of the plurality of grooves (112) is arranged in a one-to-one relationship with the plurality of cantilever portions (130, 230, 330), and each of the plurality of grooves (112) is centrally located between two adjacent pockets (134) in the circumferential direction.

7. 7. The bearing cage of claim 5, wherein each of the grooves extends to and forms part of the aft side of the annular trunk portion, and each of the grooves comprises a first segment adjacent the aft side of the annular trunk portion and a second segment inclined away from the aft side of the annular trunk portion, the first segment having a constant radial depth and the inclined second segment having a depth that decreases in a direction away from the aft side of the annular trunk portion.

8. each of the grooves has a generally trapezoidal or rectangular shape with a bottom edge at the rear side (116) of the trunk (110) and a top edge remote from the rear side (116) of the trunk (110); where: PI*dc / (Z*4)≦L2≦PI*dc / (Z*2) L1≦L2 8. The bearing cage (100, 200, 300) according to any one of claims 1 to 7, wherein L1 is the length of the top side of the trapezoidal or rectangular shape, L2 is the length of the base side of the trapezoidal or rectangular shape, dc is the inner diameter of the bearing cage, and Z is the number of rolling elements in the ball bearing.

9. 9. A bearing cage (200) according to any one of claims 1 to 8, comprising a chamfer (238a, 238b) formed on a face of the protrusion (232a, 232b) opposite the pocket formed by the protrusion.

10. 10. The bearing cage (300) of claim 1, wherein the cantilever portion (330) of the bearing cage (300) further comprises an axial protrusion (336) formed on a radially outer surface of the connecting portion (342).

11. A ball bearing (10), an inner ring (170); an outer ring (160); a plurality of rolling elements (190) disposed between the inner ring (170) and the outer ring (160); 11. The bearing cage (100, 200, 300) according to any one of claims 1 to 10, wherein the bearing cage is disposed between the inner ring (170) and the outer ring (160), and each of the plurality of rolling elements (190) is received in one of the plurality of pockets (134); and A ball bearing (10) comprising:

12. 12. The ball bearing (10) of claim 11, wherein the inner ring comprises, in an outer diameter surface (173) of the inner ring (170), raceways for receiving a plurality of the rolling elements and at least one circumferential groove (172 a, 172 b), one of the at least one circumferential groove (172 a, 172 b) at least partially overlapping with the groove (112) in the axial direction of the ball bearing.

13. 13. The ball bearing (10) of claim 12, wherein the inner ring (170) comprises two circumferential grooves (172 a, 172 b) in an outer diameter surface (173) of the inner ring (170), and the raceway (174) is disposed between the two circumferential grooves (172 a, 172 b).

14. a portion of the groove (112) extending above the raceway (174) and having an axial dimension of L3, the bottom of the groove (112) being spaced from the outer diameter surface (173) by a distance L4; where: L3>0 L4 / Dw>0.08, L4 / Dw>0.12, or L4 / Dw>0.16 14. A ball bearing (10) according to claim 12 or 13, wherein Dw is the diameter of the rolling elements.

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