Bearing cage and bearing

Abstract

The present invention relates to a bearing cage and a bearing, the bearing cage comprising: a generally annular armature part having a front side and an opposite rear side;a plurality of cantilevered parts extending from the front side of the reinforcement part in an axially forward direction of the bearing cage, the cantilevered parts being arranged along a circumference of the annular reinforcement part, defining a plurality of pockets for receiving rolling elements of the bearing, the reinforcement part having a radial thickness which is greater than that of the plurality of cantilevered parts, each of the plurality of cantilevered parts comprising two forked parts and a connecting part between the two forked parts, the bearing cage further comprising: a plurality of recesses formed in a radially outside side of the cantilevered parts, each of the recesses being defined by a connecting part in recess relative to two associated forked parts, the recess being open from the axially front side of the bearing cage;and / or a plurality of grooves (112) formed in the radially inner side (102) of the bearing cage. Figure 1.;

Description

Title of the invention: Bearing cage and bearing Technical field of the invention

[0001] The present invention relates, in general, to a cage for a ball bearing and to a ball bearing comprising such a cage. The invention also relates to a one-way press-fit bearing cage and a deep groove ball bearing comprising such a bearing cage, in particular a bearing cage and a bearing adapted for high rotational speed. Prior art

[0002] The use of a ball bearing, particularly a deep groove ball bearing, is widespread due to its low rotational friction and high performance in terms of rotational speed. A one-way press-fit cage has the advantage of low cost and easy installation, so it is normally used with a ball bearing, particularly a deep groove ball bearing.

[0003] A typical one-way snap-fit ​​cage comprises a generally annular frame and a plurality of cantilevered sections extending from one side of the frame in an axial direction. The cantilevered sections are spaced apart along the circumference of the annular frame, defining a plurality of pockets for receiving rolling elements of the bearing.

[0004] A unidirectional press-fit cage according to the prior art has the following disadvantages: as the rotational speed increases, the cantilevered parts flex radially outwards due to increased centrifugal force, producing an effect known as the umbrella effect. The umbrella effect deteriorates the matching relationship between the pockets and the rolling elements, resulting in increased friction between the cage and the rolling elements, a deterioration in performance, and / or bearing failure.

[0005] Proper lubrication is essential for high bearing performance, and excessive or insufficient lubrication will impair bearing performance.

[0006] It is still necessary to reduce the umbrella effect and improve the lubrication of a bearing. Summary of the invention

[0007] The invention relates, according to one aspect, to a bearing cage for a ball bearing, the bearing cage comprising: a generally annular armature part having a front side and an opposite rear side; a plurality of cantilevered parts extending from the front side of the armature part in a direction axially forward of the bearing cage, the cantilevered parts being arranged along a circumference of the annular reinforcement part, defining a plurality of pockets for receiving rolling elements of the bearing, the reinforcement part having a radial thickness which is greater than that of the plurality of cantilevered parts, each of the plurality of cantilevered parts comprising two forked parts and a connecting part between the two forked parts, the bearing cage further comprising: a plurality of recesses formed in a radially outside side of the cantilevered parts, each of the recesses being defined by a connecting part in recess relative to two associated forked parts, the recess being open from the axially front side of the bearing cage; and / or a plurality of grooves formed in the radially inside side of the bearing cage.

[0008] In certain embodiments of the present invention, the reinforcement part has an outside diameter greater than that of the plurality of cantilevered parts.

[0009] In certain embodiments of the present invention, the two forked parts have a radial thickness which is greater than that of the connecting part, and the forked parts extend beyond the connecting part in the axially forward direction.

[0010] In certain embodiments of the present invention, the connecting part comprises a first segment which is adjacent to the armature part and extends in an inclined manner with respect to an axis of the bearing cage, and a second segment which is away from the armature part and essentially parallel to the axis of the bearing cage.

[0011] In certain embodiments of the present invention, each of the forked parts comprises a contact surface defining the pockets and a curved surface oriented opposite to the contact surface, the recess being defined by a radially external surface of the connecting part and the curved surface.

[0012] In certain embodiments of the present invention, each of the plurality of grooves is positioned between two adjacent pockets in the circumferential direction.

[0013] In certain embodiments of the present invention, each of the plurality of grooves is positioned in pairing with the plurality of cantilevered parts, and each of the plurality of grooves is centered between two adjacent pockets in the circumferential direction.

[0014] In certain embodiments of the present invention, each of the grooves extends to the rear side of the annular reinforcement portion and forms part of the rear side of the annular reinforcement portion, each of the grooves comprising a first segment adjacent to the rear side of the annular reinforcement part and a second inclined segment away from the rear side of the annular reinforcement part, the first segment having a constant radial depth and the second inclined segment having a decreasing depth in the direction away from the rear side of the annular reinforcement part.

[0015] In certain embodiments of the present invention, each of the grooves has a generally trapezoidal shape comprising a lower edge in the rear side of the reinforcement part and an upper edge away from the rear side of the reinforcement part,

[0016] where

[0017] PI*dc / (Z *4)<=L2<=PI*dc / (Z *2),

[0018] L1<=L2,

[0019] where L1 is a length of the upper edge of the trapezoidal shape, L2 is a length of the lower edge of the trapezoidal shape, de is an inner diameter of the bearing cage, and Z is the number of rolling elements in the bearing.

[0020] In certain embodiments of the present invention, chamfers are formed on the surfaces of the forked parts opposite the pockets defined by the forked parts.

[0021] In certain embodiments of the present invention, the cantilevered parts of the bearing cage further comprise an axial projection formed on a radially external surface of the connecting part.

[0022] The invention relates, according to another aspect, to a ball bearing comprising: an inner ring; an outer ring; a plurality of rolling elements arranged between the inner ring and the outer ring; and a bearing cage according to any one of the preceding claims, the bearing cage being positioned between the inner ring and the outer ring, each of the plurality of rolling elements being received in one of the plurality of pockets.

[0023] In certain embodiments of the present invention, the inner ring comprises a raceway for receiving the plurality of rolling elements and at least one circumferential groove in an external diametrical surface of the inner ring, the or one of the circumferential groove(s) being at least partially superimposed with the grooves in an axial direction of the ball bearing.

[0024] In certain embodiments of the present invention, the inner ring comprises two circumferential grooves in the outer diametrical surface of the inner ring, the raceway being positioned between the two circumferential grooves.

[0025] In certain embodiments of the present invention, a portion of the groove extends above the rolling path, and has an axial dimension L3, and a bottom of the groove is spaced from the outer diametral surface by a distance L4,

[0026] where

[0027] L3>0,

[0028] L4 / Dw>0.08, preferably L4 / Dw>0.12 and most preferably L4 / Dw>0.16,

[0029] where Dw is a diameter of the rolling elements.

[0030] Other systems, methods, features, and advantages of the invention will be or will become apparent to those skilled in the art upon examination of the figures and the detailed description that follow. It is intended that such additional systems, methods, features, and advantages are all included in this description, fall within the scope of the invention, and are protected by the following claims. Brief description of the figures

[0031] The invention can be better understood by referring to the following drawings and description. The components in the drawings are not necessarily to scale, the important thing being to illustrate the principles of the invention. Furthermore, in the figures, identical reference numbers designate corresponding parts in all the different views.

[0032] [Fig. 1] represents a perspective view of a bearing cage according to certain embodiments of the present invention;

[0033] [Fig.2] is a first perspective view of the bearing cage of [Fig. 1] from a front viewpoint;

[0034] [Fig.3] is a second perspective view of the bearing cage of [Fig.1] from a rear view point;

[0035] [Fig.4] represents a rear view of the bearing cage of [Fig.1];

[0036] [Fig.5] is a cross-sectional view taken along line AA of [Fig.4];

[0037] [Fig.6] is a cross-sectional view taken along line BB of [Fig.4];

[0038] [Fig.7] is a cross-sectional view taken along line CC of [Fig.4];

[0039] [Fig.8] is a cross-sectional view of a ball bearing comprising a cage of bearing;

[0040] [Fig.9] is an enlarged view of the circled part of [Fig.8];

[0041] [Fig. 10] is a perspective view of a bearing cage according to another embodiment of the present invention;

[0042] [Fig. 11] represents a first perspective view of a bearing cage according to yet another embodiment of the present invention; and

[0043] [Fig. 12] represents a second perspective view of a bearing cage according to the embodiment of [Fig. 11]. Detailed description of the invention

[0044] The preferred embodiment of the present invention will be described in more detail below with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations included herein will be omitted where it might cause confusion as to the subject matter of the present invention.

[0045] As used in this document, the singular forms "a / an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "includes," "comprising," "includes," and / or "containing," as used in this document, specify the presence of the features, integers, steps, operations, elements, and / or components mentioned, 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 in this document, the term "and / or" and the symbol " / " are intended to include all combinations of one or more of the aforementioned elements. Furthermore, although the terms first, second, etc.While the terms *a* may be used in this document to describe various elements, components, steps, or calculations, these elements, components, steps, or calculations shall not be limited by them, as these terms are used only to distinguish one element, component, step, or calculation from another. For example, a first component could be called a second component, just as a first calculation could be called a second calculation; similarly, a first step could be called a second step; without departing from the scope of this invention.

[0046] As used in this document, the terms "axis," "center axis," and "axis of rotation" refer to the axis around which the bearing rotates; the terms "radial," "radially," "radial direction," and their equivalents refer to the direction from the center or axis to the circumference of the bearing cage or bearing; the terms "axial," "axially," "axial direction," and their equivalents refer to the direction along the axis of the bearing or cage, i.e., the direction perpendicular to the radial direction or the circumference of the bearing cage or bearing; the terms "front," "forward," and "front direction" refer to an axial direction in which the cantilevered portion of the bearing cage is oriented or to the axial direction along which the cantilevered portions extend from the part frame.

[0047] In order to clarify usage in the pending claims and to advise the public by this document, the expressions "at least one of , , ... And <n>» or "at least one of< / n> , , .. <n>, or combinations thereof" are defined by the Applicant in the most general sense, replacing any other prior or subsequent implied definition, unless expressly stated otherwise by the Applicant, as meaning one or more selected element(s) from the group comprising A, B, ... and N, i.e. any combination of one or more of the elements A, B, ... or N including any element alone or in combination with one or more of the other elements which may also include, in combination, additional elements not mentioned.

[0048] Figures 1 to 3 show perspective views of a bearing cage 100 according to certain embodiments of the present invention. Figure 4 shows a rear view of the bearing cage 100 of Figure 1, Figure 5 is a cross-sectional view taken along line AA of Figure 4, while Figure 6 is a cross-sectional view taken along line BB of Figure 4. Figure 7 is a cross-sectional view taken along line CC of Figure 4.

[0049] As illustrated, the bearing cage 100 comprises a generally annular reinforcement portion 110 having a front side 114 and a rear side 116 opposite the front side 114, and a plurality of cantilevered portions 130 extending from the front side 114 of the reinforcement portion in an axially forward direction of the bearing cage 100. As illustrated in [Fig. 1] to 3, the plurality of cantilevered portions 130 are preferably spaced equidistant from each other along the circumference of the annular reinforcement portion 110.

[0050] As illustrated in [Fig. 1] to 3, 5, each of the cantilevered parts 130 comprises two forked parts 132a, 132b and a connecting part 142 between the two forked parts 132a, 132b and connecting the two forked parts 132a, 132b to each other. Each of the forked parts 132a, 132b has a contact surface 133a, 133b and a curved surface 135a, 135b oriented opposite to the contact surface 133a, 133b. Each of the contact surfaces 133a, 133b of a forked portion 132a, 132b of a cantilevered portion 130 faces a contact surface 133a, 133b of an adjacent forked portion 132a, 132b of a cantilevered portion 130. Two facing contact surfaces 133a, 133b define a pocket 134 between them. Each pocket 134 is designed to receive a rolling ball from the bearing, and the contact surfaces defining the pocket 134 will be in contact with the rolling ball received in the pocket.Each of the connecting parts 142 is radially recessed relative to the two fork parts (i.e., the radially outer surface of the connecting part 142 is at a smaller radial distance from the axis of the bearing cage than the radially outer surface of the two fork parts 132a, 132b), forming a recess 144 in a radially outer side of the cantilevered parts 130. The recess 144 is defined by a . radially outer surface of the connecting part 142 and the curved surfaces 135a, 135b of the cantilevered parts 130 and is open in the axially forward direction or from the axially forward side, as best illustrated on [Fig.1] and 6.

[0051] The recesses 144 can provide additional spaces for grease storage when there is excess grease in the bearing and can add grease to the raceway when there is insufficient grease in the raceway. During bearing rotation, grease can flow from other parts of the bearing, such as the inner and outer raceways, into the recesses 144, and grease may be more likely to flow into the recesses 144 when there is more grease in the bearing. Part of the grease flowing into the recesses 144 may be temporarily blocked in the recesses 144. There will be a dynamic balancing of the grease flowing into and out of the recesses 144, and the more grease there is in the bearing, the more grease there will be in the recesses 144 when a dynamic balance is reached.Thus, the recesses 144 can store grease when there is excess grease in the bearing, and add grease to the bearing raceway when there is insufficient grease in the raceways. The recesses 144 can mitigate or eliminate the technical problem associated with excess grease. For example, the recesses 144 can reduce the heat generated during bearing acceleration and deceleration resulting from high shear between the grease and rotating parts, such as the balls and the bearing cage, when there is excess grease in the bearing. In other words, the recesses 144 can reduce or eliminate the heat generated by grease churning.

[0052] As clearly illustrated in [Fig. 1] to 3, 5, 6, the reinforcement portion 110 has a radial thickness T1, which is greater than that of the cantilevered portions 130. The radially inner surface of the reinforcement portion 110 and the radially inner surface of the cantilevered portion 130 are located at the same radial distance from the axis of the bearing cage and therefore share a common radially inner surface 102. The radially outer surface of the reinforcement portion 110 is located at a greater radial distance from the axis of the bearing cage than the cantilevered portions 130.

[0053] In the cantilevered part 130, the two forked parts 132a, 132b have a radial thickness T2, which is much greater than a radial thickness T3 of the connecting part 142. In addition, the forked parts 132a, 132b have a greater axial dimension such that they extend beyond the connecting part 142 in the axial direction, as illustrated in [Fig.1] to 3, 6, 7.

[0054] The reduced radial distance from the axis of the bearing cage to the radially outer surface of the cantilevered parts 130, i.e., the reduced outer diameter of the cantilevered parts 130, as well as the reduced amount of material due to the presence of the recesses 144, results in a reduction of the centrifugal force acting on the cantilevered parts 130. Consequently, the bearing cage has the technical advantage of reduced outward radial deflection, i.e., the so-called umbrella effect can be reduced or eliminated. The presence of the curved surfaces 135a, 135b can further reduce the amount of material in the cantilevered parts 130 and, therefore, further reduce or eliminate the so-called umbrella effect.

[0055] In certain embodiments of the present invention, the annular reinforcement portion 110 has an increased radial thickness Tl, which increases the structural strength of the bearing cage. Furthermore, as described herein, the structure of the cantilevered parts results in a reduction of the centrifugal force acting on the cantilevered parts 130. Consequently, cage deformation, i.e., the so-called umbrella effect, can be considerably reduced or eliminated by the combination of the increased radial thickness Tl and the structure of the cantilevered parts.

[0056] As illustrated in [Figs. 1 to 7], the bearing cage 100 is provided with a plurality of grooves 112 formed in the radially inner side 102 of the bearing cage 100. In some embodiments of the present invention, the plurality of grooves 112 are paired with the plurality of cantilevered parts 130. In other words, one groove 112 corresponds to each of the plurality of cantilevered parts 130. In some embodiments of the present invention, each of the plurality of grooves 112 is centered between two adjacent pockets in the circumferential direction.

[0057] As illustrated in [Fig. 1] to [Fig. 7], the grooves 112 extend to the rear side 116 of the annular reinforcement portion 110, such that the grooves 112 form part of the rear side 116 of the annular reinforcement portion. In other words, the grooves 112 are open from the rear side 116 of the annular reinforcement portion. Each of the grooves 112 comprises a first segment 112a adjacent to the rear side 116 of the annular reinforcement portion 110 and a second inclined segment 112b away from the rear side 116 of the annular reinforcement portion 110. As illustrated in [Fig. 6], the first segment 112a has a flat bottom while the second segment 112b has an inclined bottom.

[0058] As illustrated in [Fig. 1] to 7, each of the grooves 112 is centered between two adjacent pockets 134 (and therefore centered between two adjacent rolling elements 190) in the circumferential direction, and the circumferential dimension of the grooves 112 covers most of the circumferential spacing between the two adjacent rolling elements 190. Since the groove 112 is positioned between two adjacent pockets 134 (adjacent rolling elements 190) and covers most of the circumferential spacing between the two adjacent pockets 134 (adjacent rolling elements 190), it provides an additional passage or widens the passage for the flow of grease, e.g., the flow of grease between the two rolling elements 190, facilitating smooth grease flow between the two rolling elements 190 and thus improving the smooth flow of grease in the space between the inner ring and the bearing cage during bearing rotation.Furthermore, the grooves 112 can reduce or eliminate the technical problem associated with excess grease. For example, the grooves 112 can decrease the heat generated during the acceleration and deceleration of the bearing resulting from high shear between the grease and the rotating parts, such as the balls and the cage. In other words, the grooves 112 can decrease the heat generated by the churning of the grease. In some embodiments of the present invention, the amount of grease introduced is carefully chosen or adjusted and / or a special grease is used to improve lubrication, so as to decrease the heat generated by the churning of the grease.

[0059] During bearing rotation, grease can flow from the inner raceway to the grooves 112, and the grease may be more likely to flow into the grooves when there is excess grease in the inner raceway of the bearing. Some of the grease flowing into the groove 112 may be temporarily trapped in the groove, and some of the grease may return to the inner raceway. There will be a dynamic balancing of the grease flowing into and out of the grooves 112, and the more grease there is in the inner raceway, the more grease will be in the grooves 112 when a dynamic equilibrium is reached. In other words, the grooves 112 can provide additional space for grease storage when there is excess grease in the raceway.On the other hand, the grooves can add grease to the raceway when there is not enough grease in the raceways.

[0060] In certain embodiments of the present invention, the annular reinforcement portion 110 has an increased radial thickness Tl. In certain embodiments of the present invention, the gap between the annular reinforcement portion 110 and the inner ring 170 can be reduced due to the increased radial thickness Tl. Although the gap between the annular reinforcement portion 110 and the inner ring 170 is reduced, the Grease in the inner raceway can still flow smoothly due to the presence of grooves 112 between two adjacent rolling elements 190. In other words, the structural strength of the frame 110 can be improved (thanks to the increased radial thickness Tl) without compromising bearing lubrication.

[0061] In the bearing cage of the prior art, the mass distribution and structural strength are irregular along the circumference of the bearing cage. The bearing cage segments with an overhanging portion normally contain more material and exhibit greater structural strength compared to the bearing cage segments with a pocket. Compared to the bearing cage of the prior art, the bearing cage of the present invention has less material in the bearing cage segments with an overhanging portion due to the presence of the grooves 112 and / or recesses 142. Thus, the bearing cage of the present invention exhibits a more regular mass distribution and structural strength along the circumference of the bearing cage.

[0062] As described above, the bearing cage 100 exhibits increased overall structural strength and therefore a reduced umbrella effect at high rotational speeds due to the structure of the bearing cage. In the prior art, the fork portion can be subject to cracking during cage assembly if the bearing cage has increased structural strength to suppress or reduce the umbrella effect, and the bearing cage of the prior art therefore cannot have excessively high structural strength so as to reduce the risk of cracking of the fork portion.

[0063] The inventor of the present invention has discovered that the presence of grooves 112 can reduce the risk of cage cracking during cage assembly. In particular, the minimum distance S between the grooves 112 and the contact surfaces 133a, 133b, as illustrated in [Fig. 7], is a crucial factor that can influence the risk of cage cracking, and an optimal distance S can significantly reduce the risk of cage cracking during cage assembly. In other words, the bearing cage of the present invention can exhibit increased structural strength to suppress or reduce the umbrella effect, and the risk of cage cracking during cage assembly will nevertheless remain low.

[0064] Furthermore, the dimensions associated with the grooves 112, i.e. L1, L2 illustrated in [Fig. 7], L3, L4 illustrated in [Fig. 9], can be carefully chosen or optimized to obtain the optimal technical effects described above in relation to the grooves 112. As illustrated in [Fig. 7], the groove 112 has an overall trapezoidal shape when viewed in a radial direction. The overall trapezoidal shape has a lower edge in the rear side 116 of the part reinforcement 110 and an upper edge far from the rear side 116 of the reinforcement part 110. The length L1 of the upper edge of the trapezoidal shape and the length L2 of the edge of the trapezoidal shape are important factors that can influence the technical effects related to the grooves 112. As illustrated in [Fig.9], the bottom of the first segment 112a of the groove 112 is spaced from the outer diametral surface 173 of the inner ring 170 by a distance L4. Part of the groove 112 extends above the raceway 174 into the outer diametral 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 influence the technical effects of the grooves.

[0065] In certain embodiments of the present invention, L1, L2 are defined as follows:

[0066] PI*dc / (Z *4)<=L2<=PI*dc / (Z *2);

[0067] L1<=L2,

[0068] where de is the diameter of the cage bore, and Z is the number of rolling elements (rolling balls) in the bearing.

[0069] In certain embodiments of the present invention, L3, L4 are defined as follows:

[0070] L3>0 ;

[0071] L4 / Dw>0.08,

[0072] where Dw is the diameter of the rolling elements (rolling balls).

[0073] In certain other embodiments of the present invention, L4 / Dw>0.12. In still other embodiments of the present invention, L4 / Dw>0.16.

[0074] Figure 8 shows a cross-sectional view of a ball bearing 10 comprising a bearing cage 100. Figure 9 shows an enlarged view of the circled portion of Figure 8. The ball bearing 10 comprises an inner ring 170; an outer ring 160; a plurality of rolling elements 190 arranged between the inner ring 170 and the outer ring 160; and a bearing cage 100, the bearing cage being positioned between the inner and outer rings, each of the plurality of rolling elements being received in one of the plurality of pockets of the cage; and a pair of sealing elements 180 designed to seal an annular space formed between the inner ring 170 and the outer ring 160. The ball bearing includes an axial x-axis, about which the ball bearing rotates during its operation. The axial x shown in [Fig.8] is also the axis of the bearing cage 100. As best illustrated in [Fig.9], the inner ring 170 comprises an outer diametral surface 173 and a bearing race 174 formed in the outer diametral surface 173, the outer ring 160 comprises a . inner diametral surface 163 and a raceway 164 formed in the inner diametral surface 163. The inner ring 170 further includes two circumferential grooves 172a, 172b formed in the outer diametral surface 173 of the inner ring 170. Each of the two circumferential grooves 172a, 172b is located on one side of the raceway 174. The circumferential grooves 172a, 172b can store excess grease and add grease to the raceways of the bearing when there is not enough grease in the raceways of the bearing, similarly to the grooves 112 and the recesses 144 as described above. As clearly illustrated in [Fig.9], the groove 112 has a much greater axial extent than the circumferential groove 172a, and the circumferential groove 172a, 172b is positioned within the limits of the axial extent of the grooves 112 in the axial direction.In some embodiments, the grooves 112 are at least partially superimposed with the circumferential groove 172a in the axial direction. Thanks to such a configuration, the grease stored in the circumferential groove 172a can easily return to the raceway 174 via the grooves 112.

[0075] In certain embodiments of the present invention, the bearing cage is a one-way press-fit bearing cage and the ball bearing is a deep groove ball bearing.

[0076] In the embodiments illustrated in [Fig. 1] to 7, the grooves 112 are paired with the plurality of cantilevered parts 130. However, the present invention is not limited to this and, in some embodiments of the present invention, the bearing cage of the present invention may not include a groove 112.

[0077] In the embodiments shown in [Fig. 8] and [Fig. 9], the bearing of the present invention comprises two circumferential grooves 172a, 172b in the outer diametral surface 173 of the inner ring 170. However, the present invention is not limited to this, and in some embodiments, the bearing of the present invention may comprise a single circumferential groove or more than two circumferential grooves. In some embodiments, the bearing of the present invention may not comprise any circumferential groove at all.

[0078] In the illustrated embodiments, both the grooves 112 and the recesses 142 have a two-segment configuration. However, the present invention is not limited to this and, in certain embodiments, the grooves 112 and / or the recesses 142 may include any other suitable configuration, such as a smooth curved surface.

[0079] In the illustrated embodiments, the plurality of cantilevered parts are preferably spaced equidistant from each other along the circumference conference of the annular reinforcement section. However, the present invention is not limited to this and may include any other suitable configuration. In some embodiments, the plurality of cantilevered parts are spaced apart along the circumference of the annular reinforcement section. In some other embodiments, the plurality of cantilevered parts are arranged along the circumference of the annular reinforcement section.

[0080] Figure 10 is a perspective view of a bearing cage 200 according to another embodiment of the present invention. The bearing cage 200 comprises a generally annular frame portion 210 and a plurality of cantilevered portions 230. Each of the cantilevered portions 230 comprises two forked portions 232a, 232b and a connecting portion 242 between the two forked portions 232a, 232b and connecting the two forked portions 232a, 232b to each other. The bearing cage 200 is similar to the bearing cage 100 illustrated in Figures 1 to 3, except for chamfers 238a, 238b formed on the forked portions 232a, 232b. The chamfers 238a, 238b are formed on the surfaces of the forked parts 232a, 232b opposite the pockets defined by the forked parts.The 200 bearing cage has the technical advantage of reduced weight of the cantilevered parts 230, and the so-called umbrella effect can therefore be further reduced or eliminated in the 200 bearing cage.

[0081] Figures 11 and 12 are perspective views of a bearing cage 300 according to yet another embodiment of the present invention. The bearing cage 300 comprises a generally annular frame portion 310 and a plurality of cantilevered portions 330. Each of the cantilevered portions 330 comprises two forked portions 332a, 332b and a connecting portion 342 between the two forked portions 332a, 332b and connecting the two forked portions 332a, 332b to each other. The bearing cage 300 is similar to the bearing cage 100 illustrated in [Fig. 1] to 3, except for an axial projection 336 formed on the radially external surface of the connecting part 342. The bearing cage 300 has the technical advantage of improved structural resistance of the cantilevered parts 330 due to the existence of the axial projection 336.

[0082] Systems and methods have been described in general terms to facilitate understanding of the details of the invention. In some cases, well-known structures, materials, and / or operations have not been specifically illustrated or described in detail to avoid obscuring aspects of the invention. In other cases, specific details have been given to enable a complete understanding of the invention. The person skilled in the art will realize that the invention can be implemented in other specific forms, for example, to adapt it to a particular system, apparatus, situation, material, or component, without to depart from the spirit or essential features thereof. Therefore, the disclosures and descriptions made herein are for illustrative purposes only, and not for limiting the scope of the invention. The invention shall not be limited otherwise than by the attached claims and their equivalents.< / n>

Claims

Demands

1. Bearing cage (100, 200, 300) for a ball bearing, comprising: a generally annular armature part (110, 210, 310) comprising a front side (114) and an opposite rear side (116); a plurality of cantilevered parts (130, 230, 330) extending from the front side (114) of the reinforcement part (110, 210, 310) in an axially forward direction of the bearing cage, the cantilevered parts (130, 230, 330) being arranged along a circumference of the annular reinforcement part (110, 210, 310), defining a plurality of pockets (134) intended to receive rolling elements (190) of the bearing, the reinforcement part (110, 210, 310) having a radial thickness which is greater than that of the plurality of cantilevered parts (130, 230, 330), each of the plurality of cantilevered parts (130, 230, 330) comprising two forked parts (132a, 132b, 232a, 232b, 332a, 332b) and a connecting part (142, 242, 342) between the two forked parts (132a, 132b, 232a, 232b, 332a, 332b), each of the forked parts (132a, 132b) comprising a contact surface (133a, 133b) defining the pockets (134) and a curved surface (135a, 135b) oriented opposite to the contact surface (133a, 133b), the bearing cage (100, 200, 300) further comprising: a plurality of recesses formed in a radially external side of the cantilevered parts (130, 230, 330); and a plurality of grooves (112) formed in the radially inner side (102) of the bearing cage (100), characterized in that Each of the recesses is defined by a radially external surface of the connecting part (142) and the curved surface (135a, 135b), and by a connecting part recessed with respect to two associated forked parts (132a, 132b, 232a, 232b, 332a, 332b), the recess being open from the axially front side of the bearing cage (100), each of the plurality of grooves (112) being positioned between two adjacent pockets (134) in the circumferential direction, and positioned in pairing with the plurality of cantilevered parts (130, 230, 330), each of the plurality of grooves (112) being centered between two adjacent pockets (134) in the circumferential direction, and the connecting part (142, 242, 342) comprises a first segment (142a) which is adjacent to the reinforcement part (110, 210, 310) and extends inclinedly with respect to an axis of the bearing cage, and a second segment (142b) which is away from the reinforcement part and essentially parallel to the axis of the bearing cage.

2. Bearing cage (100, 200, 300) according to claim 1, wherein the reinforcement part (110, 210, 310) has an outside diameter greater than that of the plurality of cantilevered parts (130, 230, 330).

3. Bearing cage (100, 200, 300) according to any one of the preceding claims, wherein the two forked parts (132a, 132b, 232a, 232b, 332a, 332b) have a radial thickness that is greater than that of the connecting part (142, 242, 342), and the forked parts (132a, 132b, 232a, 232b, 332a, 332b) extend beyond the connecting part (142, 242, 342) in the axially forward direction.

4. Bearing cage (100, 200, 300) according to any one of claims 5 and 6, wherein each of the grooves (112) extends to the rear side (116) of the annular reinforcement portion (110, 210, 310) and forms part of the rear side (116) of the annular reinforcement portion (110, 210, 310), each of the grooves (112) comprising a first segment (112a) adjacent to the rear side (116) of the annular reinforcement portion (110, 210, 310) and a second inclined segment (112b) distant from the rear side (116) of the annular reinforcement portion (110, 210, 310), the first segment (112a) having a constant radial depth and the second inclined segment (112b) having a decreasing depth in the direction moving away from the rear side (116) of the annular frame part (110, 210, 310).

5. Bearing cage (100, 200, 300) according to any one of the preceding claims, wherein each of the grooves has an overall trapezoidal or rectangular shape comprising a lower edge in the rear side (116) of the reinforcement portion (110) and an upper edge away from the rear side (116) of the reinforcement portion (110), where PI*dc / (Z *4)<=L2<=PI*dc / (Z *2), L1<=L2, where L1 is a length of the upper edge of the trapezoidal or rectangular shape, L2 is a length of the lower edge of the trapezoidal or rectangular shape, de is an inner diameter of the bearing cage, and Z is the number of rolling elements in the ball bearing.

6. Bearing cage (200) according to any one of the preceding claims, wherein chamfers (238a, 238b) are formed on the surfaces of the forked parts (232a, 232b) opposite the pockets defined by the forked parts.

7. Ball bearing (10) comprising: an inner ring (170); an outer ring (160); a plurality of rolling elements (190) arranged between the inner ring (170) and the outer ring (160); and a bearing cage (100, 200, 300) according to any one of the preceding claims, the bearing cage being positioned between the inner ring (170) and the outer ring (160), each of the plurality of rolling elements (190) being received in one of the plurality of pockets (134).

8. Ball bearing (10) according to claim 12, wherein the inner ring comprises a raceway for receiving the plurality of rolling elements and at least one circumferential groove (172a, 172b) in an outer diametral surface (173) of the inner ring (170), the or one of the circumferential groove(s) (172a, 172b) being at least partially superimposed with the grooves (112) in an axial direction of the ball bearing.

9. Ball bearing (10) according to claim 12, wherein the inner ring (170) comprises two circumferential grooves (172a, 172b) in the outer diametral surface (173) of the inner ring (170), the raceway (174) being positioned between the two circumferential grooves (172a, 172b).

10. 10. Ball bearing (10) according to any one of claims 12 and 13, wherein a portion of the groove (112) extends above the raceway (174) and has an axial dimension L3, and a bottom of the groove (112) is spaced from the outer diametral surface (173) by a distance L4, where L3>0, L4 / Dw>0.08, preferably L4 / Dw>0.12 and most preferably L4 / Dw>0.16, where Dw is a diameter of the rolling elements.

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