Bearing structure

Abstract

The objective is to provide a bearing structure that enables miniaturization of the fitting space for bearings, shafts, and housings. [Solution] The bearing structure 100 according to the present invention is a bearing structure that rotatably supports the shaft end 112, which is the end of the shaft 110, and comprises an outer race 140, an inner race 150, and rolling elements (balls 160) that roll between the outer race 140 and the inner race 150, wherein a fitting hole 114 is formed in the shaft end 112, and the outer circumferential surface 156 of the inner race 150 is fitted into the fitting hole 114.

Description

Technical Field

[0001] The present invention relates to a bearing structure including a bearing that supports a shaft.

Background Art

[0002] Vehicles are provided with bearings that support shafts. As bearings, for example, as in Patent Document 1, those including an outer ring having an outer ring raceway on the inner peripheral surface, an inner ring having an inner ring raceway on the outer peripheral surface, and a plurality of rolling elements provided between these outer ring raceway and inner ring raceway so as to be freely rollable are common. In many cases, the outer ring of the bearing is assembled to the housing, and the inner ring supports the shaft.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, vehicles have come to be equipped with various devices such as electrical components. Therefore, in order to secure space for mounting new components in the vehicle, miniaturization of existing components is required, and further miniaturization is also required in the bearing structure.

[0005] In view of such problems, an object of the present invention is to provide a bearing structure capable of reducing the fitting space of the bearing, shaft, and housing.

Means for Solving the Problems

[0006] To solve the above problems, a typical configuration of the bearing structure according to the present invention is a bearing structure that rotatably supports the end of a shaft, the shaft end, and comprises an outer race, an inner race, and rolling elements that roll between the outer race and the inner race, wherein a fitting hole is formed at the shaft end, and the outer circumferential surface of the inner race is fitted into the fitting hole.

[0007] In this application, "outer race" is almost synonymous with "outer ring," but "inner race" includes not only the annular "inner ring" but also a solid cylindrical member with a raceway surface formed on its outer surface.

[0008] The inner lace described above may be cylindrical or cylindrical in shape.

[0009] To solve the above problems, another configuration of the bearing structure according to the present invention is a bearing structure that rotatably supports a shaft with respect to a housing, comprising an outer race, an inner race, and rolling elements that roll between the outer race and the inner race, wherein the housing has a protrusion that projects toward the shaft, and the inner circumferential surface of the outer race is fitted onto the protrusion of the housing. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a bearing structure that can reduce the size of the fitting space for the bearing, shaft, and housing. [Brief explanation of the drawing]

[0011] [Figure 1] This is a diagram illustrating the bearing structure according to the first embodiment. [Figure 2] This diagram compares the bearing structure of the first embodiment with a conventional bearing structure. [Figure 3] This is a diagram illustrating the bearing structure according to the second embodiment. [Figure 4] This is a diagram illustrating the bearing structure according to the third embodiment. [Figure 5]This diagram compares the bearing structure of the third embodiment with a conventional bearing structure. [Modes for carrying out the invention]

[0012] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in these embodiments are merely illustrative to facilitate understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same function or configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to the present invention are not shown or described.

[0013] (First Embodiment) Figure 1 is a diagram illustrating a bearing structure 100 according to the first embodiment. In the bearing structure 100 of the first embodiment shown in Figure 1, the shaft end 112, which is the end of the shaft 110, is rotatably supported by a bearing 130 assembled in the housing 120.

[0014] The bearing 130 consists of an outer race 140, an inner race 150, and balls 160 which are rolling elements that roll between the outer race 140 and the inner race 150. To briefly explain the structure of the bearing 130, one side of the inner race 150 (inner ring) protrudes toward the shaft 110.

[0015] More specifically, both the outer race 140 and the inner race 150 are cylindrical, and for example, the end faces 142 and 152 opposite the shaft end 112 are aligned. On the other hand, the end face 154 of the inner race 150 protrudes more towards the shaft end 112 than the end face 144 of the outer race 140. In other words, the inner race 150 is wider than the outer race 140.

[0016] On one side, a fitting hole 114 is formed in the shaft end 112. The outer peripheral surface 156 of the protruding end face 154 of the inner race 150 is fitted into this fitting hole 114. As a result, the raceway surface 158 of the inner race 150 is disposed closer to the center of the shaft than the outer peripheral surface 116 of the shaft 110 (the outer peripheral surface within the range where the inner race 150 is fitted).

[0017] FIG. 2 is a diagram comparing the bearing structure 100 of the first embodiment with the conventional bearing structure 10. As shown in FIG. 2, the conventional bearing structure 10 includes a bearing 20 having an outer ring 22, an inner ring 24, and balls 26 as rolling elements. In the conventional bearing structure 10, the bearing 20 is assembled to the housing 12 and is fitted onto "the outer peripheral surface 14a of the shaft 14".

[0018] In contrast, in the bearing structure 100 of the first embodiment, a fitting hole 114 is formed in the shaft end 112, and the outer peripheral surface 156 of the inner race 150 is fitted into the fitting hole 114. According to such a configuration, the ball pitch diameter PDC1 in the bearing structure 100 is smaller by D than the ball pitch diameter PDC2 in the conventional bearing structure 10. That is, with respect to the thickness of the shaft 110, the ball pitch diameter PDC1 can be made smaller than that of the conventional bearing. Therefore, according to the bearing structure 100 of the first embodiment, it is possible to reduce the size of the fitting spaces of the bearing 130, the shaft 110, and the housing 120.

[0019] Also, in the bearing structure 100 of the first embodiment, since the inner peripheral surface 159 of the inner race 150 is not used for fitting, dimensional accuracy is not required. Therefore, the inner peripheral surface 159 can remain as it is with a turning finish, and the manufacturing cost can be reduced.

[0020] (Second Embodiment) FIG. 3 is a diagram for explaining the bearing structure 200 according to the second embodiment. In the following embodiments, components common to the bearing structure 100 described above are denoted by the same reference numerals, and the description thereof is omitted.

[0021] In the bearing structure 100 of the first embodiment, the inner race 150 of the bearing 130 was cylindrical. In contrast, in the bearing structure 200 of the second embodiment, the inner race 250 of the bearing 230 is cylindrical, and the outer peripheral surface 256 of the inner race 250 is fitted into the fitting hole 114. Even with such a configuration, it is possible to obtain the same effects as those of the bearing structure 100 of the first embodiment.

[0022] (Third Embodiment) FIG. 4 is a diagram for explaining a bearing structure 300 according to the third embodiment. The bearing structure 300 of the third embodiment shown in FIG. 4 rotatably supports a shaft 310 by a bearing 330 assembled to a housing 320.

[0023] The bearing 330 includes an outer race 340, an inner race 350, and balls 160 that are rolling elements that roll between the outer race 340 and the inner race 350. To briefly explain the structure of the bearing 330, one side of the outer race 340 protrudes toward the housing 320.

[0024] Specifically, both the outer race 340 and the inner race 350 are cylindrical. As an example, the end faces 344 and 354 on the side opposite to the housing 320 are aligned. On the other hand, on the end face on the housing 320 side, the end face 342 of the outer race 340 protrudes more toward the housing 320 than the end face 352 of the inner race 350. That is, the outer race 340 is wider than the inner race 350. <The

[0025] In the bearing structure 300 of the third embodiment, a convex portion 324 that protrudes toward the shaft 310 is formed on the housing 320, and the inner peripheral surface 346 of the outer race 340 is externally fitted to the convex portion 324.

[0026] Figure 5 is a diagram comparing the bearing structure 300 of the third embodiment with the conventional bearing structure 10. In Figure 5(a), the bearing structure 300 of the third embodiment has two bearings 330, each bearing 330 supporting different shafts 310a and 310b. The outer race 340 of the bearing 330 is fitted onto the protrusion 324 of the housing 320.

[0027] In Figure 5(b), a conventional bearing structure 10 is shown with two bearings 20, each supporting a different shaft 14b and 14c. The two bearings 20 are assembled between the housing 12 and shaft 14b, and between the housing 12 and shaft 14c, respectively.

[0028] In the current unit design, the distance E between shafts is determined by the reduction ratio and gear requirements, and the bearing size is determined last. If, after testing with the determined bearing size, it is found that the bearing 20 cannot meet the allowable load, then the size of bearing 20 (a larger bearing) will need to be increased. However, since the distance E between shafts is already determined, the wall thickness F of the housing 12 between the bearings 20 must be reduced, and if the wall thickness F becomes too thin, it may be necessary to redo the unit design.

[0029] In contrast, the bearing structure 300 shown in Figure 5(a) has a configuration in which the housing 320 is not positioned on the outside of the bearing 330. Therefore, the two bearings 330 can be placed close together, making it unnecessary to consider the wall thickness F during unit design.

[0030] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. [Industrial applicability]

[0031] This invention can be used as a bearing structure that includes a bearing to support a shaft. [Explanation of Symbols]

[0032] 10…Bearing structure, 12…Housing, 14…Shaft, 14a…Outer surface, 20…Bearing, 22…Outer ring, 24…Inner ring, 26…Ball, 100…Bearing structure, 110…Shaft, 112…Shaft end, 114…Mating hole, 116…Outer surface (of the area where the inner race is fitted), 120…Housing, 130…Bearing, 140…Outer race, 142…End face, 144…End face, 150…Inner race, 152…End face 154...end face, 156...outer surface, 158...raceway surface, 159...inner surface, 160...ball, 200...bearing structure, 230...bearing, 250...inner race, 256...outer surface, 300...bearing structure, 310...shaft, 320...housing, 324...protrusion, 330...bearing, 340...outer race, 342...end face, 344...end face, 346...inner surface, 350...inner race, 352...end face, 354...end face

Claims

1. A bearing structure that rotatably supports the end of a shaft, Outer lace and, Inner lace and A rolling element that rolls between the outer race and the inner race, Equipped with, A fitting hole is formed at the end of the shaft, A bearing structure characterized in that the outer circumferential surface of the inner race is fitted into the fitting hole.

2. The bearing structure according to claim 1, characterized in that the inner race is cylindrical or columnar.

3. A bearing structure that rotatably supports an axis relative to a housing, Outer lace and, Inner lace and A rolling element that rolls between the outer race and the inner race, Equipped with, The housing has a protrusion that projects toward the axis, A bearing structure characterized in that the inner circumferential surface of the outer race is fitted onto the protrusion of the housing.

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