Rotary shaft fixing and supporting structure

Abstract

To provide a fixing support structure of a rotary shaft capable of dispensing with caulking work in assembling, and capable of preventing looseness of a nut by securing strength.SOLUTION: The ring 92 including the annular portion side 92a covering the outer periphery of the nut 90 and the claw portion side 92c extending inward in the radial direction on the axial end side of the nut 90, and the snap ring 94 fixing the ring 92 on the axial end side of the ring 92 are provided, the male spline side 90b is formed on the outer periphery of the nut 90, the female spline side 92a is formed on the inner periphery of the annular portion side 92b, and the engagement groove side 92c engaging with the claw portion side 80b is formed on the shaft 80. Thus, loosening of the nut 90 due to rotational fluctuation is regulated by engagement of the claw part 92c and the engaging groove 80b via spline fitting of the nut 90 and the ring 92, so that caulking work in assembling is dispensed with, and strength is secured to prevent loosening of the nut 90.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This relates to a fixing and supporting structure for a rotating shaft, in which the axial position of an object to be fastened on the rotating shaft is fixed by fastening a nut to the threaded portion at the end of the rotating shaft. [Background technology]

[0002] There is known a fixing and supporting structure for a rotating shaft in which the axial position of an object to be fastened on the rotating shaft is fixed by fastening a nut to a threaded portion at the end of the rotating shaft. For example, one such structure is described in Patent Document 1. Patent Document 1 discloses a structure in which the axial position of a gear fitted to the shaft is fixed by fastening a nut to a threaded portion at the end of the rotating shaft, thereby preventing the gear from coming loose. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-200015 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the fixed support structure for a rotating shaft described in Patent Document 1, if the nut loosens due to fluctuations in the rotation of the shaft, there is a risk that the gear (the object to be fastened) fixed to the shaft may also loosen. To prevent the nut from loosening, a nut with a crimping portion is used, and after fastening the nut, a crimping operation is performed to fit the nut into a groove formed in the shaft. However, this method requires time to deform the crimping portion of the nut, which increases costs. Furthermore, because the amount of deformation of the crimping portion is limited, there is an issue of insufficient strength under high loads.

[0005] The present invention was made against the background of the above circumstances, and its purpose is to provide a fixing and supporting structure for a rotating shaft that does not require crimping work during assembly, and that can ensure strength and prevent the nut from loosening. [Means for solving the problem]

[0006] The gist of the present invention is a fixed support structure for a rotating shaft, in which a threaded portion is provided on the axial end of the rotating shaft and a nut is fastened to the threaded portion to fix the axial position of an object to be fastened on the rotating shaft, the structure comprising: (a) a ring having an annular portion covering the outer periphery of the nut and claw portions extending radially inward on the axial end side of the nut, and a snap ring that fixes the ring on the axial end side of the ring; and (b) a male spline is formed on the outer periphery of the nut, a female spline is formed on the inner periphery of the annular portion, and grooves that engage with the claw portions are formed on the rotating shaft. [Effects of the Invention]

[0007] According to the rotating shaft fixing and support structure of the present invention, there is provided a ring having an annular portion covering the outer periphery of the nut and claws extending radially inward on the axial end side of the nut, and a snap ring fixing the ring on the axial end side of the ring, wherein male splines are formed on the outer periphery of the nut, female splines are formed on the inner periphery of the annular portion, and grooves are formed on the rotating shaft for engaging with the claws. As a result, loosening of the nut due to rotational fluctuations is restricted by the engagement between the claws and the grooves via the spline fit between the nut and the ring, eliminating the need for crimping during assembly and ensuring strength to prevent loosening of the nut.

[0008] Preferably, the thickness of the claws can be suitably changed to improve strength and to cope with cases where a high load is applied to the nut. Also, preferably, the number of the claws and grooves of the multiple rings can be suitably changed to reduce the load per location, which also allows the nut to cope with cases where a high load is applied to the nut. [Brief explanation of the drawings]

[0009] [Figure 1] 1(a) is a view from the shaft end side in the axial direction, and FIG. 1(b) is a cross-sectional view taken along line A-C1 in FIG. 1(a). [Figure 2] 2A and 2B are diagrams illustrating an embodiment of the present invention of a fixed support structure for a rotating shaft, in which (a) is a diagram viewed in the axial direction from the shaft end side, and (b) is a cross-sectional view taken along line B-C2 shown in FIG. 2A. [Figure 3] 3A and 3B are diagrams illustrating the shape and structure of the ring in FIG. 2, where FIG. 3A is a diagram viewed in the axial direction from the shaft end side, and FIG. 3B is a cross-sectional view of BB shown in FIG. 3A. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. [Example]

[0011] FIG. 1 is a diagram illustrating a conventional fixed support structure for a rotating shaft (hereinafter referred to as a shaft support structure) 20, in which (a) is a view in the axial direction from the shaft end side, and (b) is a cross-sectional view of A-C1 in FIG. 1(a) as viewed from the left side of the paper.

[0012] The shaft support structure 20 supports, for example, a rotating shaft (hereinafter referred to as shaft) 40 in the vehicle 10 so as to be rotatable relative to a housing 30 inside the vehicle 10. The shaft support structure 20 includes the shaft 40, a bearing 50, a spacer 52, and a nut 60.

[0013] As shown in Figures 1(a) and 1(b), a bearing 50 having a plurality of rollers 50a is fitted to the shaft 40, thereby supporting the shaft 40 so as to be rotatable about the axis C1 relative to the housing 30. In Figure 1(b), the cross section of the shaft 40 is indicated by diagonal lines. The bearing 50 is positioned in the direction of the axis C1 by a spacer 52 fitted to the outer periphery of the shaft 40, and the axial position of the bearing 50 on the shaft 40 is fixed, i.e., the bearing 50 is fixed so as not to move in the direction of the axis C1, by fastening a nut 60 to a male thread 40a formed on the outer periphery of the shaft 40 with a female thread 60a formed on the inner periphery. The bearing 50 and the spacer 52 correspond to the fastened object in this invention.

[0014] The nut 60 is provided with a cylindrical crimping portion 60b, located closer to the shaft end than the female thread 60a, to prevent loosening. In addition, crimping grooves 40b (four locations in the figure) that are recessed from the cylindrical shape are formed on the outer peripheral surface of the shaft 40 that contacts the crimping portion 60b. After the nut 60 is fastened to the shaft 40, a crimping operation is performed in which the crimping portion 60b is tightened toward the crimping grooves 40b, and the crimping portion 60b deforms and the inner peripheral portion fits into the crimping grooves 40b, restricting the rotation of the nut 60 and preventing loosening.

[0015] In the conventional example, the time required to deform the crimped portion 60b of the nut 60 is required, leading to increased costs. Furthermore, the amount of deformation of the crimped portion 60b is limited, resulting in insufficient strength under heavy loads. This is because the crimped groove 40b acts as a wall to restrict rotation when the nut 60 is rotated. However, if the amount of deformation of the crimped portion 60b is too great, it will undergo plastic deformation and lose its strength, so it is necessary to reduce the depth of the crimped groove 40b.

[0016] Therefore, in the shaft support structure of this embodiment, loosening of the nut is prevented by the structure explained later with reference to FIGS.

[0017] Fig. 2 is a diagram illustrating the shaft support structure 70 of this embodiment, where Fig. 2(a) is a diagram viewed in the axial direction from the shaft end side, and Fig. 2(b) is a cross-sectional view taken along line B-C2 in Fig. 2(a) as viewed from the left side of the page. Fig. 3 is a diagram illustrating the shape and structure of the ring in Fig. 2, where Fig. 3(a) is a diagram viewed in the axial direction from the shaft end side, and Fig. 3(b) is a cross-sectional view taken along line BB in Fig. 3(a) as viewed from the left side of the page. In the following explanation, parts common to the conventional example in Fig. 1 are designated by the same reference numerals, and explanations thereof will be omitted.

[0018] The shaft support structure 70 includes a shaft 80 , a bearing 50 , a spacer 52 , a nut 90 , a ring 92 , and a snap ring 94 .

[0019] As shown in FIGS. 2(a) and 2(b), the shaft 80 is supported by the bearing 50 for relative rotation about the axis C2 relative to the housing 30, as in the case of FIG. 1. In FIG. 2(b), the cross section of the shaft 80 is indicated by diagonal lines. The bearing 50 is positioned in the direction of the axis C2 by a spacer 52 fitted to the outer periphery of the shaft 80. The axial position of the bearing 50 on the shaft 80 is fixed, i.e., the bearing 50 is immovable in the direction of the axis C2, by fastening a nut 90 to a male thread 80a formed on the outer periphery of the shaft 80 with a female thread 90a formed on the inner periphery. The nut 90 also has a male spline 90b formed on the outer periphery in a direction parallel to the axis C2. The shaft 80 also has engagement grooves 80b (four in the figure) formed from the shaft end in the direction of the axis C2, which engage with claw portions 92c of a ring 92 (described later). The male thread 80a corresponds to the "thread portion" in this invention, and the engagement grooves 80b correspond to the "groove" in this invention.

[0020] 3, the ring 92 is a substantially disk-shaped component having an annular portion 92a, and female splines 92b that fit into male splines 90b of the nut 90 are formed on the inner peripheral surface of the annular portion 92a that covers the outer periphery of the nut 90. A portion of the disk-shaped portion of the ring 92 that is on the axial end side of the nut 90 is hollowed out, and as shown in FIG. 3(a), claw portions 92c (four portions in the figure) that extend radially inward and engage with the engaging grooves 80b of the shaft 80 when the nut 90 is attached are formed.

[0021] 2(b), the ring 92 is attached to the axial end side (right side of the drawing) of the nut 90 so that the female splines 92b fit into the male splines 90b of the nut 90 and the claws 92c fit into and engage with the engagement grooves 80b of the shaft 80. As a result, the rotation of the nut 90 is regulated by the engagement between the claws 92c of the ring 92 and the engagement grooves 80b of the shaft 80 via the spline fit between the nut 90 and the ring 92.

[0022] Preferably, the strength can be improved by suitably changing the thickness T of the claw portion 92c. Also, preferably, the load per location can be reduced by suitably changing the number of claw portions 92c and engagement grooves 80b.

[0023] The snap ring 94 is a ring with spring properties, and is fitted into a fixing groove 80c of the shaft 80 on the axial end side of the ring 92, fixing the ring 92 so that it does not move in the direction of the axis C2.

[0024] As described above, this embodiment includes the ring 92 having the annular portion 92a covering the outer periphery of the nut 90 and the claw portions 92c extending radially inward on the axial end side of the nut 90, and the snap ring 94 that secures the ring 92 on the axial end side of the ring 92, and the male spline 90b is formed on the outer periphery of the nut 90, the female spline 92b is formed on the inner periphery of the annular portion 92a, and the engagement groove 80b that engages with the claw portions 92c is formed in the shaft 80. As a result, loosening of the nut 90 due to rotational fluctuations is regulated by the engagement between the claw portions 92c and the engagement groove 80b via the spline fit between the nut 90 and the ring 92, eliminating the need for crimping during assembly and ensuring strength to prevent loosening of the nut 90.

[0025] Furthermore, according to this embodiment, the thickness T of the claw portions 92c can be suitably changed to improve strength and accommodate cases where a high load is applied to the nut 90. Furthermore, the number of claw portions 92c and engagement grooves 80b can be suitably changed to reduce the load per location, which also allows the nut 90 to accommodate cases where a high load is applied.

[0026] The above describes in detail an embodiment of the present invention based on the drawings, but what has been described above is merely one embodiment, and the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0027] 50: bearing (object to be fastened), 52: spacer (object to be fastened), 70: shaft support structure (fixed support structure for rotating shaft), 80: shaft (rotating shaft), 80a: male screw (threaded portion), 80b: engagement groove, 90: nut, 90b: male spline, 92: ring, 92a: annular portion, 92b: female spline, 92c: claw portion, 94: snap ring

Claims

[Claim 1] A fixing and supporting structure for a rotating shaft, in which a threaded portion is provided at an end of the rotating shaft, and a nut is fastened to the threaded portion to fix the axial position of a fastened object on the rotating shaft, a ring having an annular portion covering the outer periphery of the nut and claw portions extending radially inward on the axial end side of the nut; and a snap ring fixing the ring on the axial end side of the ring, A male spline is formed on the outer periphery of the nut, a female spline is formed on the inner periphery of the annular portion, and a groove that engages with the claw portion is formed on the rotating shaft. A fixed support structure for a rotating shaft.

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