Spherical slide bearing

Abstract

To provide a spherical slide bearing that can prevent a crease from generating without any impact on sliding motion.SOLUTION: A spherical slide bearing (1) of the present disclosure includes: an inner ring (2) in which a slide surface (2a) of a convex spherical surface is formed; an outer ring (4) in which a slide surface (4a) of a concave spherical surface is formed; and a sheet-like slide member (6) affixed to an inner diameter surface of the outer ring (4). In the spherical slide bearing (1), a groove (20) recessed on a radial outside is provided in an axial end in the inner diameter surface of the outer ring (4).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an oil-free spherical plain bearing that functions as both a radial bearing that supports radial loads and a thrust bearing that supports axial loads. [Background technology]

[0002] A spherical plain bearing is known that includes an inner ring with a convex spherical surface and an outer ring with a concave spherical sliding surface (see, for example, Patent Document 1). In such a spherical plain bearing, the sliding portion is spherical and can withstand thrust loads in addition to radial loads. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-327737 Summary of the Invention [Problem to be solved by the invention]

[0004] In an oil-free spherical plain bearing such as that disclosed in Patent Document 1, a sheet-like sliding member is affixed to the spherical surface of the outer ring of the spherical plain bearing. In this case, if the difference between the inner diameter of the outer ring and the spherical diameter (i.e., the diameter of the concave spherical surface of the outer ring) increases, the contact area in the curved state increases, making the sliding member more susceptible to wrinkling. Generally, rectangular sliding members are affixed to the spherical surface of the outer ring with adhesive, and wide sliding members with deep spherical grooves are prone to wrinkling at both end faces of the sliding member, which can prevent proper attachment. If a load is applied when wrinkles have formed, excessive surface pressure will be generated in the wrinkled areas, potentially causing the sliding member to peel off.

[0005] In response to this, it is possible to prevent wrinkles from occurring by providing slits 102 at both ends of the sheet-like sliding member 100, as shown in Figure 8. However, providing slits 102 makes it impossible to adhere the sliding member 100 uniformly. Furthermore, gaps are generated where the sliding member 100 and slits 102 meet, and adhesive flows into these gaps, which may impair the sliding properties of the bearing or cause the sheet to peel off.

[0006] An object of the present invention is to provide a spherical plain bearing that can prevent wrinkles from occurring in the sliding member without affecting sliding motion. [Means for solving the problem]

[0007] The spherical plain bearing of the present invention comprises an inner ring formed with a convex spherical sliding surface, an outer ring formed with a concave spherical sliding surface, and a sheet-like sliding member attached to the inner diameter surface of the outer ring, wherein a recessed portion recessed radially outward is provided at an axial end portion of the inner diameter surface of the outer ring. The recessed portion is, for example, a V-shaped or U-shaped groove.

[0008] With this configuration, a recess is provided in the spherical portion of the outer ring of the spherical plain bearing, allowing the sheet-shaped sliding member to be attached along the recess. As a result, the sheet-shaped sliding member can be prevented from wrinkling. Furthermore, because the recess is shaped to be recessed radially outward of the outer ring, it does not affect sliding motion.

[0009] In the present invention, the recesses may be provided in an odd number and spaced apart circumferentially. If recesses are located on a diagonal line, the strength of the outer ring along that diagonal line may be reduced. With this configuration, because there are an odd number of recesses, they are not located on a diagonal line, and therefore reduction in the strength of the outer ring can be suppressed.

[0010] In the present invention, the recesses may be provided at both axial ends of the inner diameter surface of the outer ring, with the recesses at one axial end and the recesses at the other axial end being provided at the same circumferential position. With this configuration, both end portions of the sliding member that are prone to wrinkling can be attached so that they are aligned with the recesses. As a result, wrinkling of the sheet-like sliding member can be effectively prevented.

[0011] In the present invention, the recesses may extend from the axial end toward the center, and the circumferential width thereof may gradually decrease from the axial end toward the center. With this configuration, the width of the recesses is set larger at the end of the sliding member, which is prone to wrinkling, so that the end of the sliding member can be attached along the wider recesses. As a result, the occurrence of wrinkles in the sheet-like sliding member can be effectively prevented. [Effects of the Invention]

[0012] The spherical plain bearing of the present invention can prevent wrinkles from occurring in the sliding member without affecting sliding motion. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a longitudinal cross-sectional view showing a spherical plain bearing according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the outer ring of the spherical plain bearing. [Figure 3] FIG. [Figure 4] FIG. 2 is a vertical cross-sectional view showing the outer ring. [Figure 5] FIG. 10 is a front view showing a modified example of the outer ring. [Figure 6] FIG. 4 is a longitudinal cross-sectional view showing a spherical plain bearing according to a second embodiment of the present invention. [Figure 7] FIG. 2 is a vertical cross-sectional view showing the outer ring. [Figure 8] FIG. 10 is a plan view showing an example of a sliding member that has been treated to prevent wrinkles. [Figure 9] FIG. 10 is a plan view showing another example of a sliding member having anti-wrinkle measures. DETAILED DESCRIPTION OF THE INVENTION

[0014] A preferred embodiment of the present invention will now be described with reference to the drawings. In the following description, the terms "axial direction," "radial direction," and "circumferential direction" refer to the "axial direction," "radial direction," and "circumferential direction" of the wheel bearing, respectively.

[0015] Figure 1 shows a spherical plain bearing 1 according to a first embodiment of the present invention. Spherical plain bearing 1 is used in situations where mounting errors on a shaft that undergoes low-speed oscillating motion, or shaft deflection or torsion due to load are not elastically tolerable. The spherical plain bearing 1 of this embodiment is an oil-free, i.e., self-lubricating, radial spherical plain bearing. This spherical plain bearing 1 has a spherical sliding surface and can withstand thrust loads in addition to radial loads.

[0016] As shown in FIG. 1, the spherical plain bearing 1 comprises an inner ring 2 having a convex spherical sliding surface 2a formed thereon, an outer ring 4 having a concave spherical sliding surface 4a formed thereon, and a sheet-like sliding member 6 attached to the sliding surface 4a, which is the inner diameter surface of the outer ring 4.

[0017] The inner ring 2 and outer ring 4 are made of, for example, high-carbon chromium bearing steel, and the sliding surface 2a of the inner ring 2 is hard chrome plated. However, the materials for the inner ring 2 and outer ring 4 are not limited to this. In this embodiment, the outer ring 4 has a two-piece structure split along the axial direction. The two-piece outer ring 4 is integrated with a snap ring 10 fitted into a groove 8 provided on its outer periphery.

[0018] The sheet-like sliding member 6 is made, for example, of a synthetic resin with high self-lubricating properties, and is adhered along the sliding surface 4a of the concave spherical outer ring 4. This forms a spherical plain bearing 1 having a concave spherical sliding surface 4a of the outer ring 4 to which the sliding member 6 is adhered. The sliding member 6 is adhered along the sliding surface 4a of the outer ring 4, for example, with an adhesive. However, the material of the sliding member 6 and the adhesion method are not limited to this.

[0019] The spherical plain bearing 1 of this embodiment is used, for example, in a vehicle suspension system. The outer ring 4 of the spherical plain bearing 1 is fitted into a mounting groove 12a formed in a housing 12 of an actual suspension system, and is fixed in the axial direction by an end plate 14. The inner ring 2 of the spherical plain bearing 1 is fitted onto a shaft 16. In this way, the spherical plain bearing 1 is assembled into the actual system.

[0020] The recessed portion 20 of the present invention will be described using Figures 2 to 4. Figures 2 to 4 are a perspective view, a front view, and a longitudinal cross-sectional view, respectively, of the outer ring 4 of the spherical plain bearing 1 of this embodiment. As shown in Figure 2, a recessed portion 20 recessed radially outward is provided at the axial end of the inner diameter surface 4a of the outer ring 4. The recessed portion 20 of this embodiment is a groove 20 recessed radially outward.

[0021] As shown in Fig. 3, in this embodiment, the groove 20 is V-shaped when viewed in the axial direction. However, the groove 20 is not limited to a V-shape. For example, as shown in a modified example in Fig. 5, the groove 20 may be U-shaped. Furthermore, the groove 20 may have a shape other than a V-shape or U-shape.

[0022] As shown in Fig. 3, a plurality of grooves 20 are provided spaced apart in the circumferential direction. In this embodiment, an odd number of grooves 20, five in the illustrated example, are provided spaced apart in the circumferential direction. The five grooves 20 are arranged at equal intervals in the circumferential direction. However, the number of grooves 20 is not limited to the illustrated example.

[0023] As shown in Fig. 4, in this embodiment, the grooves 20 are provided at both axial ends of the inner diameter surface 4a of the outer ring 4. The grooves 20 at one axial end and the grooves 20 at the other axial end are provided at the same circumferential position. In other words, the grooves 20 at one axial end and the grooves 20 at the other axial end are provided side by side in the axial direction. However, the circumferential positions of the grooves 20 at one axial end and the grooves 20 at the other axial end may be offset from each other.

[0024] The grooves 20 extend from the axial ends toward the center. In this embodiment, the circumferential width of the grooves 20 gradually decreases from the axial ends toward the center. However, the circumferential width of the grooves 20 may be constant.

[0025] Next, the attachment of the sheet-like sliding member 6 will be described. As described above, the sliding member 6 is attached to the inner diameter surface 4a of the outer ring 4 with an adhesive. At this time, the occurrence of wrinkles can be prevented by aligning the sliding member 6 with the grooves 20 in the inner diameter surface 4a of the outer ring 4 and smoothing out any wrinkles. Furthermore, when attaching the sliding member 6, it can be pressed with an inner ring 2 having an outer diameter surface that matches the irregularities of the grooves 20 in the outer ring 4, or it can be fixed by pressing it with the jaws of a chuck device that match the shape of the grooves 20.

[0026] Unlike the examples shown in Figures 8 and 9 in which slits 102 and 103 are provided in sliding member 100, in the present embodiment shown in Figure 1, there is no need to provide slits in sliding member 6, so no gaps occur at the joint between sliding member 6 and the slits. In addition, there is no need for a process of providing slits in sliding member 6. However, to make it easier to align sliding member 6 with groove 20, V-shaped slit 102 shown in Figure 8 or linear slit 103 shown in Figure 9 may be provided.

[0027] The groove 20 shown in Figure 3 is recessed, and does not affect sliding motion. As shown in Figure 2, the outer ring 4 of the spherical plain bearing 1 has a split structure in which V-shaped grooves 20 are provided diagonally in the outer ring 4 in order to fit the inner ring 2, and when a load is applied using a press or similar machine, the outer ring 4 is split into two at the V-shaped groove, with a split line 22 formed on the inner diameter surface 4a of the outer ring 4. The presence of these V-shaped grooves 20 and split line 22 does not affect sliding motion, so providing grooves 20 on the inner diameter surface 4a of the outer ring 4 does not affect sliding motion.

[0028] According to the above configuration, grooves 20 are provided on the inner diameter surface 4a of the outer ring 4 of the spherical plain bearing 1, so that the sheet-like sliding member 6 can be attached along the grooves 20. As a result, it is possible to prevent wrinkles from forming in the sheet-like sliding member 6. Furthermore, because the grooves 20 are shaped to be recessed radially outward, they do not affect sliding motion.

[0029] As shown in Figure 3, an odd number of grooves 20 are provided, spaced equally apart around the circumference. The more grooves 20 there are, the easier it is to prevent wrinkles from occurring. However, because the load capacity of the spherical plain bearing 1 varies with contact area, increasing the number of grooves 20 reduces the load capacity. In particular, if grooves 20 are located on diagonal line D, there is a risk that the strength of the outer ring 4 will decrease along diagonal line D. With this configuration, because there are an odd number of grooves 20 and they are not located on diagonal line D, it is possible to prevent wrinkles from occurring while also suppressing a decrease in the strength of the outer ring 4.

[0030] As shown in Fig. 4, grooves 20 are provided at both axial ends of the inner diameter surface 4a of the outer ring 4, with the groove 20 at one axial end and the groove 20 at the other axial end being provided at the same position in the circumferential direction. With this configuration, both end portions of the sliding member 6, which are prone to wrinkling, can be attached along the grooves 20. As a result, the occurrence of wrinkling in the sliding member 6 can be effectively prevented.

[0031] The grooves 20 extend from the axial ends toward the center, and their circumferential width gradually decreases from the axial ends toward the center. With this configuration, the width of the grooves 20 is set larger at the ends of the sliding member 6, which are prone to wrinkling, so the ends of the sliding member 6 can be attached along the wider grooves 20. As a result, the occurrence of wrinkles in the sliding member 6 can be effectively prevented.

[0032] Figure 6 shows a spherical plain bearing according to a second embodiment of the present invention. In the example of Figure 6, a thrust spherical plain bearing 30 is combined with the radial spherical plain bearing 1 of the first embodiment shown in Figure 1. As the structure of the radial spherical plain bearing 1 is the same as that of the first embodiment shown in Figure 1, common reference numerals are used and a description thereof will be omitted.

[0033] The thrust spherical plain bearing 30 comprises an inner ring 32 having a convex spherical sliding surface 32a formed thereon, an outer ring 34 having a sliding surface 34a, which is the inner diameter surface of a concave spherical surface, and a sheet-like sliding member 36 attached to the inner diameter surface 34a of the outer ring 34.

[0034] The inner ring 32 is attached to a small-diameter shaft 16a formed at the end of the shaft body 16, and the sliding surface 32a is formed as a convex hemispherical surface. The outer ring 34 has a concave spherical sliding surface 34a formed along the outer periphery of the sliding surface 32a of the inner ring 32. The materials of the inner ring 32, outer ring 34, and sliding member 36 are the same as those in the first embodiment. In the second embodiment, both radial and thrust loads are supported by the radial spherical plain bearing 1 and the thrust spherical plain bearing 30. Therefore, the second embodiment can support a greater thrust load than the first embodiment.

[0035] As shown in Figure 7, a recess 40 recessed radially outward is provided at the axial end of the inner diameter surface 34a of the outer ring 34 of the thrust type spherical plain bearing 30. Like the recess 20 of the first embodiment, the recess 40 of the second embodiment is a V-shaped groove 40 recessed radially outward.

[0036] In the second embodiment, a plurality of grooves 40 are also provided at equal intervals in the circumferential direction. An odd number of grooves 40 are preferably provided at intervals in the circumferential direction. The grooves 40 are provided at both axial ends of the inner diameter surface 34a of the outer ring 34, and the grooves 40 at one axial end and the grooves 40 at the other axial end are provided at the same circumferential position.

[0037] The grooves 40 extend from the axial ends toward the center, and their circumferential widths gradually decrease from the axial ends toward the center, i.e., the grooves 40 have the largest circumferential widths at the axial ends.

[0038] In the second embodiment, the grooves 40 are also provided on the inner diameter surface 34a of the outer ring 34 of the spherical plain bearing 30, and therefore the same effects as those of the second embodiment are achieved.

[0039] The present invention is not limited to the above-described embodiment, and various additions, modifications, and deletions are possible without departing from the spirit and scope of the present invention. For example, in the above-described embodiment, the groove 20 is V-shaped or U-shaped when viewed from the axial direction, but it may also be rectangular. Therefore, such configurations are also included within the scope of the present invention. [Explanation of symbols]

[0040] 1 Radial spherical plain bearing (spherical plain bearing) 2,32 Inner circle 2a, 32a Inner ring sliding surface 4,34 outer ring 4a, 34a Sliding surface of outer ring (inner diameter surface) 6,36 Sliding member 20,40 recess (groove) 30 Thrust spherical plain bearing (spherical plain bearing)

Claims

1. A spherical plain bearing comprising an inner ring formed with a convex spherical sliding surface, an outer ring formed with a concave spherical sliding surface, and a sheet-like sliding member attached to the inner diameter surface of the outer ring, a spherical plain bearing in which a recessed portion recessed radially outward is provided at an axial end portion of the inner diameter surface of the outer ring;

2. 2. The spherical plain bearing according to claim 1, wherein the recess is a V-shaped or U-shaped groove.

3. 3. The spherical plain bearing according to claim 1, wherein an odd number of the recesses are provided and spaced apart in the circumferential direction.

4. 3. The spherical plain bearing according to claim 1 or 2, wherein the recesses are provided at both axial ends of the inner diameter surface of the outer ring, A spherical plain bearing in which the recessed portion at one axial end and the recessed portion at the other axial end are provided at the same position in the circumferential direction.

5. 3. The spherical plain bearing according to claim 1, wherein the recess extends from an end portion in the axial direction toward a center portion, A spherical plain bearing whose circumferential width gradually decreases from the axial ends to the center.

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