Cage segment, cage and ball bearing
By dividing the cage into segments and setting bosses on the segments to accommodate the ball diameter, the high cost and unstable operation of thin-section ball bearings are solved, achieving low-cost manufacturing and stable assembly.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AB SKF SKF PATENT DEPARTMENT
- Filing Date
- 2024-12-10
- Publication Date
- 2026-06-12
AI Technical Summary
The cages of existing thin-section ball bearings are expensive to manufacture and their dimensions change significantly due to thermal expansion and contraction, leading to unstable bearing operation and inconvenient assembly.
The cage is divided into multiple segments, each with a boss. The width of the boss is adapted to the diameter of the ball to ensure the stability of the position between the cage and the ball during bearing operation. The segments are manufactured using small molds and assembled into a complete cage.
It reduces the manufacturing cost of the cage, improves the operating stability and assembly convenience of the bearing, and avoids the impact of dimensional changes caused by thermal expansion and contraction.
Smart Images
Figure CN122191195A_ABST
Abstract
Description
Technical Field
[0001] The present invention provides a cage segment, a cage, and a ball bearing. Background Technology
[0002] Bearings are widely used in various fields, and their structures and models are also diverse. There exists a type of thin-section ball bearing with relatively large diameters for both the inner and outer rings, but relatively thin walls for both rings; this type is typically used in large rotating structures.
[0003] The cages used in these types of bearings are typically large in size and relatively thin. The conventional method for manufacturing cages is to injection mold them as a single unit. However, this requires developing large molds, resulting in high manufacturing costs. Furthermore, these large cages are prone to significant dimensional changes due to thermal expansion and contraction, leading to decreased bearing operational stability and inconvenient cage assembly.
[0004] Therefore, there is a need in the art for an improved cage that is suitable for such large-diameter, thin-section ball bearings, while reducing costs, facilitating assembly, and not affecting bearing operation. Summary of the Invention
[0005] In response to the problems and needs mentioned above, this disclosure proposes a novel technical solution that solves the aforementioned problems and brings about other technical effects by adopting the following technical features.
[0006] A cage segment for forming a ball bearing cage, the ball bearing defining an axial direction, a radial direction, and a circumferential direction, the cage segment comprising: a plurality of pockets, each pocket being formed as a spherical pocket having a sphere center; wherein a boss projecting in the radial direction is formed on at least one of the outer and inner circumferential surfaces of the cage segment, the boss having a spherical side surface continuing with the inner surface of the pocket, and the geometric center of the boss being located on a section passing through the sphere center of the pocket and perpendicular to the axial direction, wherein the width d of the portion where the top surface of the boss intersects the spherical side surface satisfies the following relationship with the ball diameter Dw: d = 0.05 × Dw - 0.30 × Dw.
[0007] By placing bosses at specific locations along the cage segments, and ensuring these bosses have a width appropriate to the ball diameter, the relative position between the cage and the balls can be ensured during bearing operation, preventing abnormal radial runout or misalignment. Therefore, even if the cage is manufactured in sections, the overall bearing operation can be guaranteed without affecting its performance. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of a ball bearing according to a preferred embodiment of the present invention;
[0009] Figure 2This is a schematic diagram of a cage segment according to a preferred embodiment of the present invention;
[0010] Figure 3-6 The specific features of the protrusions on the cage segment according to a preferred embodiment of the present invention are shown;
[0011] Figure 7 This is a schematic diagram of the connection structure of the cage segment according to a preferred embodiment of the present invention;
[0012] Figure 8 The diagram illustrates the angular relationship between the end pockets of adjacent cage segments in a bearing according to a preferred embodiment of the present invention. Detailed Implementation
[0013] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.
[0014] Compared to the embodiments shown in the accompanying drawings, feasible embodiments within the scope of this disclosure may have fewer components, other components not shown in the drawings, different components, components arranged differently, or components with different connections, etc. Furthermore, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.
[0015] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by those skilled in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Where the number of components is not specified, the number of components may be one or more; similarly, terms such as “a,” “the,” and “described” do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “install,” “set,” “connect,” or “link” are not limited to physical or mechanical installation, setting, or connection, but may include electrical installation, setting, or connection, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate the relative positional relationship of the equipment during use or as shown in the accompanying drawings; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0016] For ease of explanation, the direction of the bearing's axis of rotation is referred to as the axial direction, and the direction perpendicular to this axial direction is referred to as the radial direction. The term "inner / inward" refers to the direction toward the inside of the bearing, while the term "outer / outward" refers to the direction toward the outside of the bearing. Furthermore, in different embodiments, the same reference numerals are used to refer to components having the same or similar structure and function.
[0017] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
[0018] As previously stated, this invention proposes a cage that is particularly suitable for large-diameter bearings such as thin-section ball bearings (e.g.,...). Figure 1 (As shown). For example, the pitch circle diameter Dm of a typical thin-section bearing is 0.25m≤Dm≤1m, where the bearing pitch circle is defined as the diameter of the circle passing through the center line of the bearing balls.
[0019] To address the issue of cage manufacturing costs, this invention proposes dividing the cage into segments, each with the same structure. This allows for the mass production of multiple segments using smaller and simpler molds, compared to manufacturing the entire cage using a single large mold. These segments can be molded from materials such as rubber, resin, or polymers (e.g., nylon). These cage segments are then assembled together during bearing assembly to form a complete cage. Furthermore, segments of the same or similar length can be used to assemble cages with different diameters to accommodate bearings of varying diameters, eliminating the need to redesign cage molds for different diameter bearings.
[0020] In addition, due to the large size of thin-section ball bearings and the large number of balls they contain, the cage assembled from multiple segments also faces the problem of unstable position between the cage and the balls during bearing operation (especially the positional deviation between the two in the radial direction), which will further cause instability in bearing operation.
[0021] Therefore, as Figure 2-4 As shown, the present invention proposes an optimized cage segment 1.
[0022] Specifically, the cage segment 1 includes a plurality of pockets 10, each pocket 10 being formed as a spherical pocket with a ball center. For example, when the total number of balls in the bearing is Z, the number of pockets X contained in each cage segment can be: 3≤X≤(Z-2) / 2.
[0023] Bosses 13 protruding in the radial direction are formed on the outer peripheral surface 11 and the inner peripheral surface 12 of the cage segment 1, thereby providing a retaining effect on the rolling balls on both the inner and outer radial sides. It should be understood that although in the preferred embodiment shown in the figures, the bosses 13 are formed on both the outer peripheral surface 11 and the inner peripheral surface 12, depending on specific requirements, the bosses 13 may also be formed on only one of the outer peripheral surface 11 and the inner peripheral surface 12.
[0024] The boss 13 has a spherical side surface 130 that is continuous with the inner surface of the pocket 10 (e.g., Figure 4 As shown in the enlarged perspective view, the spherical side 130 of the boss 13 and the inner surface of the pocket 10 are both components of the same spherical surface. Furthermore, the specific shape of the boss 13 can be set as needed, and a simple geometric shape is generally more conducive to the manufacturing and molding of the retainer segment mold.
[0025] The present invention further proposes that, regardless of the geometry of the boss 13, its position should be located at a specific position on the bearing carrier segment to provide effective retention for the rolling balls. See further details. Figure 5 The geometric center (not shown) of the boss 13 should be located on a section 101 passing through the center of the ball in the pocket and perpendicular to the axial direction, so that after the bearing is assembled, the boss 13 can substantially hold the ball along the axial direction and in the diameter direction of the ball. Furthermore, the width d of the portion where the top surface 131 of the boss intersects with the spherical side surface 130 satisfies the following relationship with the ball diameter Dw: d = 0.05 × Dw - 0.30 × Dw. That is, the present invention proposes that the boss 13 should be designed according to the specific diameter of the ball to provide sufficient holding width for the ball along the axial direction. It should be understood that, for simplicity, Figure 5 The ball is not shown, but Figure 6 The ball is indicated by a dashed circle.
[0026] In summary, by placing bosses at specific locations within the cage segments, and ensuring these bosses have a width appropriate to the ball diameter, the relative positional stability between the cage and the balls can be ensured during bearing operation, preventing abnormal radial runout, misalignment, or other issues. Therefore, even if the cage is manufactured in segments, the overall bearing operation can be guaranteed without affecting its performance.
[0027] More preferably, see Figure 6 The bearing includes an outer ring OR and an inner ring IR. Correspondingly, bosses 13 are provided on both the outer circumferential surface 11 and the inner circumferential surface 12 of the cage segment 1. Specifically, when an outer boss 13 is provided on the outer circumferential surface 11 and an inner boss 13 is provided on the inner circumferential surface 12 of the cage segment 1, the diameter of the arc surface containing the top surface of the outer boss 13 is the outer diameter Dc1, and the diameter of the arc surface containing the top surface of the inner boss 13 is the inner diameter dc1. The outer ring of the ball bearing has an outer ring shoulder inner diameter Dk, and the inner ring has an inner ring shoulder outer diameter dk. The cage segment 1 has an inner diameter dc and an outer diameter Dc.
[0028] Furthermore, this invention proposes that the inner diameter dc, outer diameter Dc, outer boss outer diameter Dc1, inner boss inner diameter dc1, outer ring shoulder inner diameter Dk, inner ring shoulder outer diameter dk, and ball diameter Dw of cage segment 1 satisfy the following:
[0029] 1.15×(Dc-dc)<(Dc1-dc1) / 2<0.95×(Dk-dk) / 2.
[0030] Therefore, this invention comprehensively considers the requirements of the cage for bearing assembly and operation, and designs the relationship between the thickness of the cage segment, the height of the boss and the inner and outer ring shoulders of the bearing, so as to facilitate assembly and better retain the rolling balls, without affecting the operation of the bearing.
[0031] As previously described, the boss 13 of the cage segment 1 has a spherical side surface 130 extending from the inner surface of the pocket. In addition to the spherical side surface 130, the boss 13 also has other side surfaces, a top surface, and a bottom surface. Generally, the overall shape of the boss can be set as needed. In a preferred embodiment of the invention, the other side surfaces, top surface, and bottom surface of the boss 13 conform to a frustum shape, particularly a regular frustum shape, such as... Figure 5 As shown.
[0032] Furthermore, the top surface 131 of the boss has two side edges A and B extending in the circumferential direction, and the two side edges A and B are at an equal distance ds from the cross-section 101, and the distance ds satisfies the following relationship with the diameter Dw of the rolling ball: ds = 0.025×Dw - 0.15×Dw. Therefore, it can be understood that the axial width d of the boss 13 is d = 2ds. In other words, when the boss 13 is in the shape of a frustum of a pyramid, the top surface 131 of the boss is symmetric with respect to the cross-section 101. At the same time, when the boss 13 has the preferred width d as described above, the boss 13 has a better holding effect on the rolling ball. Further preferably, the side surface 132 of the boss 13 opposite to its spherical side surface 130 has an angle of 10 - 90 degrees with respect to the bottom surface of the boss, preferably an angle of 30 degrees (see Figure 3 ). This relatively inclined boss design enables the boss to better withstand the force from the rolling ball and prevents cracking at the root of the boss (i.e., near the bottom surface).
[0033] Of course, the boss can also have other shapes. For example, according to a preferred embodiment not shown, except for the spherical side surface, the other side surfaces, the top surface and the bottom surface of the boss conform to the shape of a frustum of a cone, and the top surface of the boss is partially circular, and its center is located on the cross-section 101. Preferably, the generatrix of the frustum of the cone has an angle of 10 - 90 degrees with respect to the bottom surface of the boss, preferably an angle of 30 degrees.
[0034] Further preferably, the width W of the top surface 131 of the boss in the cross-section 101 satisfies the following relationship with the diameter Dw of the rolling ball of the ball bearing: 0.05×Dw < W. This ensures that the boss 13 has sufficient width in the circumferential direction to increase its own strength, and further increase its holding force on the rolling ball.
[0035] In addition, since the bearing often rotates at high speed for a long time, the cage is also prone to fatigue failure due to frequent stress. According to research, the cage often fails at the root of the pocket claw. Therefore, the present invention further proposes an improvement scheme for this fatigue failure situation.
[0036] According to a preferred embodiment, as Figure 2-5 shown, each pocket 10 has a pair of claws 15 extending from the first side surface 141 of the cage segment body 14, and in the circumferential direction, a pair of bosses 13 are formed on both sides of each pocket 10, such that the pair of bosses 13 are formed corresponding to the pair of claws 15, and the bottom surface of each boss 13 at least partially covers the root of the corresponding claw 15 (as Figure 5 shown). This root is the part where the claw 15 is connected to the first side surface 141. Thus, since the boss 13 is located at the root of the claw, it provides a strengthening structure for the root of the claw, enhancing the anti-fatigue performance of the claw, and further increasing the life of the entire cage.
[0037] Furthermore, the present invention optimizes the position of the pocket in the cage segment and the structure of the cage segment itself.
[0038] Specifically, the distance C of the second side 142 of the cage segment body 14 opposite to the first side 141 from the center of the pocket ball satisfies the following relationship with the diameter Dw of the rolling ball: C>0.60×Dw.
[0039] The inner diameter dc, outer diameter Dc of cage segment 1 and the diameter Dw of the rolling ball satisfy the following relationship:
[0040] 0.3×Dw<(Dc-dc) / 2<0.5×Dw.
[0041] like Figure 8 As shown, the diameter R of the center plane of cage segment 1 and the diameter Dw of the rolling ball satisfy the following relationship:
[0042] R = (0.05 ~ 0.15) × Dw.
[0043] This ensures that the bearing segments have optimized strength and flexibility, thereby ensuring the stability of the bearing during operation.
[0044] As mentioned earlier, the cage segment 1 is assembled to form a complete cage. For some low-speed bearings, the cage segment only needs to be placed tightly against the bearing, meaning that it is not necessary to connect the cage segments.
[0045] For some high-speed bearings, a certain degree of connection strength is required between the cage segments to prevent undesirable wobble caused by loose cage segments. Therefore, such as Figure 7 As shown, cage segment 1 includes a first end face 16 and a second end face 17 located at both ends of cage segment 1 in the circumferential direction. The first end face 16 includes a slot 160, and the second end face 17 includes an insert 170 that conforms to the shape of the slot 160, so that adjacent cage segments 1 can be assembled together. It should be understood that, in addition to the cylindrical insert and slot shown, slots and inserts of any other shape can be provided as needed.
[0046] Furthermore, regardless of how the cage segments are connected, adjacent cage segments 1 have a mating surface. It should be understood that this mating surface is a virtual surface; for example, in low-speed bearings as described above, this mating surface coincides with the end faces of the cage segments that are in close contact; or in high-speed bearings where adjacent cage segments are engaged by slots or inserts, this mating surface is a radial surface 102 passing through the geometric center of the insert (e.g., ...). Figure 8(As shown). Therefore, those skilled in the art will understand that regardless of how the cage segments are assembled, there is a mating surface between adjacent cages. Furthermore, the present invention also proposes that the centers of the two pockets on both sides of the mating surface and immediately adjacent to the mating surface have equal angular distances a and b between them and the mating surface, such as... Figure 8 As shown. This further optimizes the matching relationship between the ends of adjacent cage segments and ensures that the pockets at the ends of the cage segments are also in the correct position.
[0047] The present invention also proposes a ball bearing comprising a cage composed of cage segments as described above.
[0048] The exemplary embodiments of this disclosure have been described in detail above with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of this disclosure, and various combinations can be made to the various technical features and structures proposed in this disclosure without exceeding the protection scope of this disclosure, which is determined by the appended claims.
Claims
1. A cage segment (1) for forming a ball bearing cage, the ball bearing defining an axial direction, a radial direction, and a circumferential direction, the cage segment (1) comprising: Multiple pockets (10), each pocket (10) being formed as a spherical pocket with a sphere center; In this design, a radially projecting boss (13) is formed on at least one of the outer peripheral surface (11) and the inner peripheral surface (12) of the cage segment (1). The boss (13) has a spherical side surface (130) that is continuous with the inner surface of the pocket (10), and the geometric center of the boss (13) is located on a section (101) that passes through the center of the pocket and is perpendicular to the axial direction. Among them, the width d of the part where the top surface (131) of the boss intersects with the spherical side surface (130) satisfies the following relationship with the diameter Dw of the rolling ball: d = 0.05 × Dw - 0.30 × Dw.
2. The cage segment (1) as described in claim 1, wherein, The cage segment (1) has an inner diameter dc and an outer diameter Dc; The boss (13) is provided on both the outer peripheral surface (11) and the inner peripheral surface (12) of the cage segment (1), namely, the outer boss on the outer peripheral surface (11) of the cage segment (1) and the inner boss on the inner peripheral surface (12) of the cage segment, wherein the diameter of the arc surface where the top surface of the outer boss is located is the outer diameter Dc1 of the outer boss, and the diameter of the arc surface where the top surface of the inner boss is located is the inner diameter dc1 of the inner boss; The ball bearing has an outer ring shoulder inner diameter Dk and an inner ring shoulder outer diameter dk; Among them, the inner diameter dc, outer diameter Dc, outer boss outer diameter Dc1, inner boss inner diameter dc1, outer ring shoulder inner diameter Dk, inner ring shoulder outer diameter dk and ball diameter Dw of the cage segment (1) satisfy the following: 1.15×(Dc-dc)<(Dc1-dc1) / 2<0.95×(Dk-dk) / 2.
3. The cage segment (1) as described in claim 1, wherein, Except for the spherical side surface (130), the other sides, top surface, and bottom surface of the boss (13) conform to the shape of a quadrangular frustum, and among them, The top surface (131) of the boss has two sides extending in the circumferential direction, and the two sides are equidistant from the cross section (101) by a distance ds, and this distance ds satisfies the following relationship with the diameter Dw of the rolling ball: ds = 0.05 × Dw - 0.30 × Dw. Preferably, the side (132) of the boss (13) opposite to its spherical side (130) has an angle of 10-90 degrees with respect to the bottom surface of the boss, preferably an angle of 30 degrees; or Except for the spherical side surface, the other side surface, top surface and bottom surface of the boss conform to the shape of a truncated cone, and the center of the top surface of the boss is located on the cross section (101); preferably, the generatrix of the truncated cone has an angle of 10-90 degrees with respect to the bottom surface of the boss, preferably an angle of 30 degrees.
4. The cage segment (1) as described in claim 3, wherein, The width W of the top surface (131) of the boss in the cross section (101) satisfies the following relationship with the ball diameter Dw of the ball bearing: 0.05×Dw <W。 5. The cage segment (1) as claimed in claim 1, wherein, Each pocket (10) has a pair of claws (15) extending from a first side (141) of the cage segment body (14), and a pair of bosses (13) are formed on both sides of each pocket (10) in the circumferential direction, such that the pair of bosses (13) are formed correspondingly to the pair of claws (15), and the bottom surface of each boss (13) at least partially covers the root of the corresponding claw (15), wherein the root is the portion where the claw (15) connects to the first side (141).
6. The cage segment (1) as described in claim 5, wherein, The distance C of the second side (142) of the cage segment body (14) opposite to the first side (141) from the center of the pocket ball satisfies the following relationship with the diameter Dw of the rolling ball: C>0.60×Dw.
7. The cage segment (1) as claimed in claim 1, wherein, The cage segment (1) has an inner diameter dc and an outer diameter Dc, and the inner diameter dc, the outer diameter Dc and the ball diameter Dw satisfy the following relationship: 0.3×Dw < (Dc-dc) / 2 < 0.5×Dw; and / or The cage segment (1) has a center plane diameter R, and the center plane diameter R and the ball diameter Dw satisfy the following: R = (0.05 ~ 0.15) × Dw.
8. The cage segment (1) as claimed in any one of claims 1-7, comprising a first end face (16) and a second end face (17) located at both ends of the cage segment (1) in the circumferential direction, the first end face (16) comprising a slot (160) and the second end face (17) comprising an insert (170) conforming to the shape of the slot (160) such that adjacent cage segments (1) can be assembled together.
9. A cage for a ball bearing, comprising a plurality of cage segments (1) as described in claims 1-8; preferably, adjacent cage segments (1) have a mating surface, wherein, The centers of the two pockets on both sides of the joint surface and adjacent to the joint surface have equal angular distances from the joint surface.
10. A ball bearing comprising the cage as claimed in claim 9.