gear

Abstract

This invention relates to a gear capable of suppressing resonance and reducing gear noise. The gear (1) has a plurality of meshing teeth (3) formed at regular intervals on the outer periphery of a disc-shaped disk portion (2). A plurality of weight-reducing portions (4) are arranged along the circumferential direction on the disk portion (2). The spacing between the weight-reducing portions (4) along the predetermined circumferential direction is different at least at one location from other locations in the predetermined circumferential direction. Therefore, by providing the weight-reducing portions (4), gear noise caused by changes in rigidity in the circumferential direction can be suppressed. Furthermore, since the spacing between the weight-reducing portions (4) is different at least at one location from other locations in the predetermined circumferential direction, the rigidity of the gear (1) becomes uneven, making resonance less likely. As a result, gear noise caused by resonance can be reduced.

Description

Technical Field

[0001] This utility model relates to gears equipped with structures for suppressing gear noise. Background Technology

[0002] Various technical solutions have been proposed in the past for suppressing gear noise (sound and vibration) generated when two gears mesh. For example, in the vehicle gear described in Patent Document 1 and the meshing gear of a vehicle described in Patent Document 2, a plurality of through holes are arranged in the circumferential direction between the boss portion on the central side and the edge portion with teeth, connecting the arc-shaped slits and the circular holes. These through holes are parts that can be called weight-reducing parts, and the rigidity of each part of the disc varies complexly depending on the presence or shape of the through holes. As a result, the vibration characteristics also change, and thus, gear noise can be suppressed.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-063790

[0006] Patent Document 2: Japanese Patent Application Publication No. 2011-247348 Utility Model Content

[0007] The problem to be solved by the utility model

[0008] The through holes in the gears described in Patent Documents 1 and 2 are formed by creating circular holes at one or both ends of an arc-shaped slit. Multiple through holes (three in the figures of Patent Documents 1 and 2) are provided at equal intervals along the circumference of the disk. That is, in the gear structure described in Patent Documents 1 or 2, the disk can be divided into three regions based on the through holes. However, since the through holes have the same shape, the rigidity of these regions is the same. Furthermore, the pattern of rigidity variation in the circumferential direction within each region is the same. In other words, the gear structure described in Patent Documents 1 or 2 has a periodic structure when the rigidity of the disk is observed along the circumferential direction.

[0009] However, gear noise is not only generated by the repeated meshing of teeth, but also by resonance with vibrations transmitted from the outside. Generally, resonance of a rotating body containing gears is more likely to occur when the rigidity of the rotating body is point-symmetric with respect to the center point. Such resonance can be identified by analyzing the shape (mode) of circular vibration of integer order to determine the antinodes and nodes.

[0010] As described above, the rigidity of the gears described in Patent Documents 1 and 2 varies periodically in the circumferential direction, forming a rigidity pattern that is close to point-symmetric even if it is not point-symmetric with respect to the center point. Therefore, the gear structures described in Patent Documents 1 and 2 are prone to resonance, and there is a possibility that the gear noise will increase due to resonance.

[0011] This invention was made in view of the above-mentioned technical issues, and its purpose is to provide a gear that can suppress resonance and reduce gear noise levels.

[0012] Methods for solving problems

[0013] To achieve the above objectives, the present invention relates to a gear in which multiple meshing teeth are formed at certain intervals on the outer periphery of a disc-shaped disk portion, and multiple weight-reducing portions are arranged on the disk portion along the circumferential direction. The gear is characterized in that the spacing between the weight-reducing portions in the specified circumferential direction of the disk portion is different at at least one location from other locations in the specified circumferential direction.

[0014] Effects of the utility model

[0015] In this invention, the spacing between the weight-reducing portions in the disc portion along a predetermined circumferential direction differs from that of other portions at least at one location. Therefore, by providing these weight-reducing portions, gear noise caused by variations in rigidity along the circumferential direction can be suppressed. Furthermore, because the spacing between these weight-reducing portions differs from that of other portions along the predetermined circumferential direction at least at one location, the gear's rigidity becomes uneven, making resonance less likely. As a result, gear noise caused by resonance can be reduced. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating a gear in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures:

[0018] 1 gear

[0019] 2 disks

[0020] 3 teeth

[0021] 4 Weight Loss Section

[0022] P center point Detailed Implementation

[0023] like Figure 1As shown, in an embodiment of this utility model, the gear 1 has a disc-shaped disk portion 2 mounted on a rotating shaft (not shown) and rotates integrally around the rotating shaft. Multiple meshing teeth 3 are formed at regular intervals on the outer periphery of the disk portion 2, meshing with other gears (not shown). Here, Figure 1 The gear shown is a spur gear with tooth lines that are straight lines parallel to the axis of rotation, but it is not limited to this.

[0024] Furthermore, at a predetermined distance along the radial direction from the center point P of the disk portion 2, a plurality of oblong weight-reducing portions 4 are arranged in the circumferential direction. Additionally, in the gear 1 of this invention, the spacing between the weight-reducing portions 4 in the predetermined circumferential direction of the disk portion 2 differs from that in at least one location in the predetermined circumferential direction from the other locations.

[0025] Next, the spacing between the weight-reducing parts 4 in the circumferential direction will be explained. For example, as... Figure 1 As shown, the disk portion 2 is divided into 8 equal parts in the circumferential direction. (The dividing lines are represented by double-dotted lines.) Furthermore, when a certain defined region is designated as region 1 (i), the weight-reducing portions 4 are formed clockwise in the circumferential direction in the regions numbered with prime numbers, starting from region 1. In this embodiment, since the prime numbers are in the interval from region 1 to region 8, these are the four regions: region 2 (ii), region 3 (iii), region 5 (v), and region 7 (vii). By forming the weight-reducing portions 4 with prime number numbers, the spacing between the weight-reducing portions 4 in at least one location in the defined circumferential direction is different from the other locations.

[0026] In the embodiment of this utility model, the spacing between the weight-reducing portions 4 in the predetermined circumferential direction of the disk portion 2 differs from that of other portions at least at one location in the predetermined circumferential direction. Therefore, by providing the weight-reducing portions 4, gear noise caused by variations in rigidity in the circumferential direction can be suppressed. Furthermore, since the spacing between the weight-reducing portions 4 differs from that of other portions in the predetermined circumferential direction at least at one location, the rigidity of the gear 1 becomes uneven, making it less prone to resonance. As a result, gear noise caused by resonance can be reduced.

[0027] Furthermore, the above embodiments are merely one example of implementing this utility model and do not limit the scope of this utility model. For example, in this embodiment, the weight-reducing portion 4 is formed into an oblong shape; however, it is not limited to this and can also be a perfect circle or an asymmetrical shape in the radial direction. In short, it is acceptable as long as the spacing between the weight-reducing portions 4 differs from each other at least at one location in the predetermined circumferential direction.

Claims

1. A gear, wherein a plurality of meshing teeth are formed at certain intervals on the outer periphery of a disc-shaped disk portion, and a plurality of weight-reducing portions are arranged along the circumferential direction on the disk portion, characterized in that, The spacing between the weight-reducing portions of the disc in the prescribed circumferential direction is different from that in at least one location in the prescribed circumferential direction.

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