gear

Abstract

To provide a gear capable of suppressing noise.SOLUTION: A damper 300 is equipped with a first cylindrical member 310 to be fitted with an inner peripheral surface of an outer ring 100, a second cylindrical member 320 to be fitted with an outer peripheral surface of an inner ring 200, and a plurality of elastic shock absorbers 330 to be fixed to an inner peripheral surface of the first cylindrical member 310 and an outer peripheral surface of the second cylindrical member 320. At an end portion of a cylinder portion 311 in the first cylindrical member 310, an outward flange portion 312 provided so as to face an end surface of the outer ring 100 is provided. Between the end surface of the outer ring 100 and the outward flange portion 312, an elastic body 332 is sandwiched while being compressed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a gear. [Background technology]

[0002] For example, in the case of gears installed in the drive units of automobiles, a technique for providing a cushioning elastic body to suppress noise is known. That is, a technique is known in which the gear includes an outer ring, an inner ring, and an annular elastic body provided between the outer ring and the inner ring. However, while this technique is effective in reducing abnormal noise by reducing vibrations caused by rotational fluctuations, it is unable to sufficiently suppress high-frequency abnormal noise caused by meshing of the teeth (gears), and there is still room for improvement. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-362346 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a gear capable of suppressing noise. [Means for solving the problem]

[0005] The present invention employs the following means to solve the above problems.

[0006] That is, the gear of the present invention has the following features: an outer ring having a plurality of teeth on an outer periphery; an inner ring disposed concentrically inside the outer ring; an annular damper disposed between the outer ring and the inner ring; Equipped with A gear having a rotation prevention structure provided between an inner peripheral surface of the outer ring and an outer peripheral surface of the inner ring, the rotation prevention structure limiting relative rotation between the outer ring and the inner ring within a certain range, The damper is a first cylindrical member fitted to an inner peripheral surface of the outer ring; a second cylindrical member fitted onto an outer peripheral surface of the inner ring; an annular elastic buffer fixed to an inner circumferential surface of the first cylindrical member and an outer circumferential surface of the second cylindrical member; In addition to providing The end of the cylindrical portion of the first cylindrical member is provided with an outward flange portion that faces the end face of the outer ring, and an elastic body is sandwiched in a compressed state between the end face of the outer ring and the outward flange portion.

[0007] According to the present invention, the provision of an elastic buffer reduces vibrations caused by rotational fluctuations between the outer ring and the inner ring, thereby reducing abnormal noise. Furthermore, the elastic buffer is sandwiched in a compressed state between the end face of the outer ring and the outward flange portion provided at the end of the first cylindrical member, which also provides the effect of suppressing high-frequency abnormal noise caused by meshing of the teeth.

[0008] The elastic buffer and the elastic body may be provided integrally. [Effects of the Invention]

[0009] As described above, according to the present invention, noise can be suppressed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front view of a gear according to an embodiment of the present invention. [Figure 2] FIG. 2 is a front view showing a state in which the gear damper according to the embodiment of the present invention has been removed. [Figure 3] FIG. 3 is a schematic cross-sectional view of a gear according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following detailed description of the present invention will be given by way of example with reference to the accompanying drawings, although the dimensions, materials, shapes, relative positions, etc. of the components described in the examples are not intended to limit the scope of the present invention unless otherwise specified.

[0012] (Example) A gear according to an embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a front view of the gear according to the embodiment of the present invention. Figure 2 is a front view of the gear according to the embodiment of the present invention with the damper removed. Figure 3 is a schematic cross-sectional view of the gear according to the embodiment of the present invention. Note that Figure 3 is a cross-sectional view taken along line AA in Figure 1. The outer ring and inner ring in Figure 3 correspond to the cross-sectional view taken along line AA in Figure 2. Hereinafter, the central axis of the gear will be referred to as the "central axis."

[0013] <Gear configuration> The gear 10 according to this embodiment is a so-called helical gear. This gear 10 includes an outer ring 100 having a plurality of teeth 110 on its outer periphery, an inner ring 200 concentrically disposed inside the outer ring 100, and an annular damper 300 disposed between the outer ring 100 and the inner ring 200. The tooth traces of the plurality of teeth 110 extend obliquely relative to the central axis. The outer ring 100 and the inner ring 200 are made of a hard material. While metals such as iron are preferably used as this material, other hard materials such as resins may also be used.

[0014] A rotation prevention structure is provided between the inner peripheral surface of outer ring 100 and the outer peripheral surface of inner ring 200, which limits the relative rotation between outer ring 100 and inner ring 200 to a certain range. More specifically, a plurality of protrusions 120 are provided at circumferential intervals on the inner peripheral surface of outer ring 100, and a plurality of protrusions 220 are also provided at circumferential intervals on the outer peripheral surface of inner ring 200. In this embodiment, all of the plurality of protrusions 120 have the same dimensions and shape and are provided at equal intervals in the circumferential direction. Similarly, all of the plurality of protrusions 220 have the same dimensions and shape and are provided at equal intervals in the circumferential direction. Furthermore, a protrusion 220 is arranged between adjacent protrusions 120, and a gap is formed between the protrusions 120 and the protrusions 220. With the above configuration, the outer ring 100 and the inner ring 200 are allowed to rotate relative to each other within a certain range, and when an external force causes rotational motion and the protrusions 120 and 220 come into contact, the outer ring 100 and the inner ring 200 rotate together.

[0015] A large diameter portion 130 to which damper 300 is fixed is provided on the inner peripheral surface of outer ring 100. Furthermore, a small diameter portion 230 to which damper 300 is fixed is provided on the outer peripheral surface of inner ring 200. As a result, damper 300 is fixed in the annular gap between outer ring 100 and inner ring 200 with its outer peripheral surface fitted to the inner peripheral surface of large diameter portion 130 and its inner peripheral surface fitted to the outer peripheral surface of small diameter portion 230.

[0016] The gear 10 according to this embodiment has a tilt suppression structure that suppresses the tilt of the outer ring 100 relative to the inner ring 200 (tilt relative to the central axis) while allowing the outer ring 100 and the inner ring 200 to rotate relative to each other within a certain range. A tilt suppression structure is formed by sliding against vertical wall surface 150 and wall surface 250 provided on inner ring 200 and perpendicular to the central axis. In this embodiment, the inner surface of an inward flange portion provided on the end of outer ring 100 opposite the side to which damper 300 is fixed plays the role of wall surface 150. In addition, the end face of the end of inner ring 200 opposite the side to which damper 300 is fixed plays the role of wall surface 250.

[0017] By having such a tilt suppression structure, tilt of the outer ring 100 relative to the inner ring 200 (tilt relative to the central axis) is suppressed. That is, in a helical gear, when an external force (a force in the rotational direction) acts on the multiple teeth 110 of the outer ring 100, a force that twists the outer ring 100 acts on the outer ring 100. This acts to tilt the outer ring 100 relative to the inner ring 200, but by having the tilt suppression structure, tilt of the outer ring 100 can be suppressed. This suppresses the generation of abnormal noise.

[0018] <Damper> The damper 300 will now be described in more detail. The damper 300 comprises a first cylindrical member 310 fitted onto the inner circumferential surface (large diameter portion 130) of the outer ring 100, and a second cylindrical member 320 fitted onto the outer circumferential surface (small diameter portion 230) of the inner ring 200. The first cylindrical member 310 comprises a cylindrical portion 311 and an outward flange portion 312 provided at the end of the cylindrical portion 311. The outward flange portion 312 is provided so as to face the end face of the outer ring 100.

[0019] The damper 300 also includes an annular elastic buffer 330 fixed to the inner circumferential surface of the first cylindrical member 310 and the outer circumferential surface of the second cylindrical member 320. The elastic buffer 330 is made of an elastomer material (such as rubber) and is directly fixed to the inner circumferential surface of the first cylindrical member 310 and the outer circumferential surface of the second cylindrical member 320 by vulcanization bonding or the like. The elastic buffer 330 also includes a buffer main body 331 disposed so as to fill the annular gap between the inner circumferential surface of the first cylindrical member 310 and the outer circumferential surface of the second cylindrical member 320, and an elastic body 332 sandwiched in a compressed state between the end face of the outer ring 100 and the outward flange portion 312. The buffer main body 331 and the elastic body 332 are integrally formed. That is, the outward flange portion 312 is covered with the elastomer material, thereby forming the buffer main body 331 and the elastic body 332 integrally. The elastic body 332 is preferably provided so as to contact the tooth 110 of the outer ring 100, and is also preferably provided so as to be able to contact the mating tooth 500 that meshes with the tooth 110. Note that Fig. 3 also shows an enlarged cross-sectional view of the circled portion in the figure, and in this enlarged view, the position of the mating tooth 500 when the tooth 110 meshes with the mating tooth 500 is indicated by a thick dotted line. The thickness of the elastic body 332 (thickness in the left-right direction in the figure) should preferably be set in the range of 0.5 mm to 3 mm.

[0020] <Advantages of the gear (helical gear) according to this embodiment> The gear 10 according to this embodiment can transmit rotational motion between a member (such as a rotating shaft) to which the inner ring 200 is fixed and a member (such as a gear) that meshes with the teeth 110 of the outer ring 100. In the case of low torque, rotational motion is transmitted between the outer ring 100 and the inner ring 200 via the damper 300. Furthermore, by providing an anti-rotation structure, rotational motion is transmitted directly between the outer ring 100 and the inner ring 200 when torque exceeding a certain level is applied. Furthermore, the damper 300 reduces vibrations caused by rotational fluctuations, thereby reducing abnormal noise. Furthermore, the elastic body 332 is sandwiched in a compressed state between the end face of the outer ring 100 and the outward flange portion 312 provided at the end of the first cylindrical member 310, thereby suppressing high-frequency abnormal noise caused by meshing of the teeth. In other words, suppressing tooth vibrations that occur when the teeth mesh effectively suppresses high-frequency abnormal noise. [Explanation of symbols]

[0021] 10 Gears 100 outer ring 110 teeth 120 protrusions 130 Large diameter part 150 Wall 200 Inner Circle 220 protrusion 230 Small diameter section 250 Wall 300 Damper 310 First cylindrical member 311 Cylindrical part 312 Outward flange 320 Second cylindrical member 330 Elastic buffer 331 Buffer body 332 Elastic Body 500 teeth

Claims

1. an outer ring having a plurality of teeth on an outer periphery; an inner ring disposed concentrically inside the outer ring; an annular damper disposed between the outer ring and the inner ring; Equipped with A gear having a rotation prevention structure provided between an inner peripheral surface of the outer ring and an outer peripheral surface of the inner ring, the rotation prevention structure limiting relative rotation between the outer ring and the inner ring within a certain range, The damper is a first cylindrical member fitted to an inner peripheral surface of the outer ring; a second cylindrical member fitted onto an outer peripheral surface of the inner ring; an annular elastic buffer fixed to an inner peripheral surface of the first cylindrical member and an outer peripheral surface of the second cylindrical member; In addition to providing a first cylindrical member having an end portion at a cylindrical portion thereof, the end portion being provided with an outward flange portion opposed to an end face of the outer ring, and an elastic body being sandwiched in a compressed state between the end face of the outer ring and the outward flange portion.

2. 2. The gear according to claim 1, wherein the elastic buffer body and the elastic body are integrally provided.

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