JP2021179224A - gear - Google Patents

Abstract

To provide a gear that can suppress rattling noise while maintaining strength of the gear.SOLUTION: A gear 1 includes: a gear body 3 including multiple tooth parts 9 in the outer periphery thereof; and a low elastic member 5 provided at least inside of the tooth part 9 so as not to be exposed from a tooth surface 9f, and having an elastic modulus that is lower than the gear body 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to gears.

The gear includes a metal bush, a resin member provided around the metal bush and having teeth formed on the outer periphery thereof, and an elastic member provided between the metal bush and the resin member. Is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2017-015100

By the way, in recent years, with the increasing demand for noise reduction, it is required to suppress the rattling noise (also referred to as meshing noise) generated when the gears mesh with each other. Various measures can be considered to suppress the rattling noise, but the strength of the gear may decrease due to the measures.

One aspect of the present invention is to provide a gear capable of suppressing rattling noise while maintaining the strength of the gear.

The gear according to one aspect of the present invention includes a gear body having a plurality of tooth portions on the outer periphery, and a low elastic member provided at least inside the tooth portions so as not to be exposed from the tooth surface and having a lower elastic modulus than the gear body. , Equipped with.

In this gear, since the low elasticity member exists inside the tooth portion, the tooth portion itself in which the tooth striking sound is generated can have the damping effect thereof, and the tooth striking sound can be effectively suppressed. Further, since the low elasticity member is provided so as not to be exposed from the tooth surface, it is possible to suppress the decrease in the tooth surface strength due to the presence of the low elasticity member inside the tooth portion, and by extension, the tooth surface strength can be suppressed. , It is possible to prevent the strength of the gear from being lowered. Therefore, it is possible to suppress the rattling noise while maintaining the strength of the gear.

In the gear according to one aspect of the present invention, the low elasticity member may be arranged only inside the tooth portion. This configuration makes it easier to maintain the strength of the gear.

In the gear according to one aspect of the present invention, the low elasticity member may be provided inside all the tooth portions among the plurality of tooth portions. With this configuration, the rattling noise can be further suppressed. In addition, it becomes easy to secure the symmetry around the axis of the gear.

In the gear according to one aspect of the present invention, the low elasticity member may be provided inside every N tooth portion (N is an integer of 1 or more). This configuration makes it easier to maintain the strength of the gear. In addition, it becomes easy to secure the symmetry around the axis of the gear.

In the gear according to one aspect of the present invention, the low elasticity member may be provided so as to be exposed from at least one of the end face and the top face of the tooth portion. In this configuration, for example, the low elasticity member can be easily filled inside the tooth portion, and the low elasticity member can be easily provided.

According to the present invention, it is possible to provide a gear capable of suppressing rattling noise while maintaining the strength of the gear.

FIG. 1 is a perspective view of a gear according to the first embodiment. FIG. 2A is a perspective view showing a method of manufacturing the gear of FIG. FIG. 2B is a perspective view showing the continuation of FIG. 2A. FIG. 3A is a cross-sectional view showing a continuation of FIG. 2B. FIG. 3B is a cross-sectional view showing a continuation of FIG. 3A. 4 (a) is a perspective view showing the continuation of FIG. 3 (b). FIG. 4B is a perspective view showing the continuation of FIG. 4A. FIG. 4 (c) is a perspective view showing the continuation of FIG. 4 (b). FIG. 5 is a perspective view of the gear according to the second embodiment. FIG. 6A is a perspective view showing a method of manufacturing the gear of FIG. FIG. 6B is a perspective view showing the continuation of FIG. 6A. 7 (a) is a perspective view showing the continuation of FIG. 6 (b). 7 (b) is a perspective view showing the continuation of FIG. 7 (a). FIG. 8 is an enlarged perspective view showing a part of the gear according to the modified example. FIG. 9 is an enlarged perspective view showing a part of the gear according to another modified example. FIG. 10 is an enlarged perspective view showing a part of the gear according to another modified example.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicate description will be omitted.

[First Embodiment]
The first embodiment will be described. As shown in FIGS. 1 and 2, the gear 1 according to the first embodiment is a metal gear and is used as a gear for a vehicle or an industrial use. For example, the gear 1 can be used for a balance shaft gear, a camshaft gear, or the like in an engine. The gear 1 includes a gear body 3 and a low elasticity member 5. The gear 1 is a spur gear.

The gear body 3 is, for example, a member attached to a rotating shaft (not shown). The gear body 3 is a member that meshes with other gears. The gear body 3 is made of a metal such as stainless steel. The gear main body 3 has a main body portion 7 and a plurality of tooth portions 9. The main body 7 is annular. The main body 7 is provided with a through hole 7h. The through hole 7h penetrates one end surface of the main body 7 and the other end surface. A rotation shaft is inserted into the through hole 7h. A plurality of tooth portions 9 are provided on the outer periphery of the main body portion 7. A plurality of tooth portions 9 are formed at predetermined intervals in the circumferential direction of the main body portion 7. A hole 11 is provided in each of the plurality of tooth portions 9. The hole 11 penetrates one end surface 9a and the other end surface 9b of the tooth portion 9. The hole 11 here is a circular hole. The holes 11 are provided only in the tooth portion 9 and not in the main body portion 7.

The low elasticity member 5 is a member that attenuates the rattling noise generated when the gear 1 meshes with another gear. The low elasticity member 5 is provided in the holes 11 of the plurality of tooth portions 9. That is, the low elasticity member 5 is provided at least inside the tooth portion 9 so as not to be exposed from the tooth surface 9f. The low elastic member 5 has a lower elastic modulus than the gear body 3. The low elasticity member 5 is made of rubber, for example. The rubber is butadiene rubber, chloroprene rubber, butyl rubber, styrene butadiene rubber, nitrile rubber, ethylene propylene rubber, acrylic rubber, fluororubber, epichlorohydrin rubber, silicone rubber and the like. The rubber is preferably fluororubber or silicone rubber from the viewpoint of durability and heat resistance.

In the illustrated example, the low elasticity member 5 is provided inside all the tooth portions 9 among the plurality of tooth portions 9. The low elasticity member 5 is provided only inside the tooth portion 9, and is not provided in the main body portion 7. The low elasticity member 5 is filled inside the hole 11 without a gap. The low elasticity member 5 is provided so as to be flush with the end face 9a and the end face 9b of the tooth portion 9. The low elasticity member is provided so as to be exposed from the end face 9a and the end face 9b of the tooth portion 9.

Subsequently, an example of a method for manufacturing the gear 1 will be described.

The method for manufacturing the gear 1 according to the present embodiment includes a metal member processing step, a hole processing step, an elastic member forming step, and a gear cutting process. Hereinafter, each step will be described in order.

<Metal member processing process>
In the metal member processing step, as shown in FIG. 2A, the annular metal member 20 is formed. In the metal member processing step, the metal member 20 is cut to adjust the dimensions of the metal member 20. In the metal member processing process, the metal member 20 is machined by a machine tool such as a lathe. Specifically, in the metal member processing step, the outer diameter portion and the inner diameter portion side surface of the metal member 20 are scraped, and the metal member 20 is processed to a predetermined size. After cutting the metal member 20, the metal member 20 is washed.

<Hole processing process>
In the hole processing step, as shown in FIG. 2B, hole processing is performed to form a plurality of holes 11 on the outer peripheral portion of the metal member 20. For example, in the hole drilling process, a plurality of holes 11 are formed on the outer peripheral portion of the metal member 20 so as to be lined up along the circumferential direction by using a drill of a machine tool such as a drilling machine.

<Elastic member forming process>
In the elastic member forming step, the low elastic member 5 is formed in the hole 11 of the metal member 20. For example, in the elastic member forming step, as shown in FIG. 3A, the metal member 20 in which the plurality of holes 11 are formed is arranged in the lower mold 31. Subsequently, as shown in FIG. 3B, the rubber material G is pushed into the hole 11 by the upper mold 32, and the rubber material G is injected and filled in the hole 11. Then, the filled rubber material G is vulcanized and heated. As a result, as shown in FIG. 4A, the low elasticity member 5 is formed in the hole 11 of the metal member 20. If necessary, burrs on the low elasticity member 5 are removed.

<Tooth cutting process>
In the gear cutting step, as shown in FIGS. 4 (b) and 4 (c), the gear cutting of the metal member 20 is performed by combining the phases of the position of the low elasticity member 5 and the position of the tooth portion 9. conduct. Applicable gear cutting includes finishing with a hobbing or shaving machine. By the gear cutting process, the tooth portion 9 including the low elasticity member 5 is formed so that the low elasticity member 5 is exposed from the end face 9a and the end face 9b and the low elasticity member 5 is not exposed from the tooth surface 9f. NS. The gear 1 is manufactured by the above steps. The method for manufacturing the gear 1 is not limited to the above-mentioned method, and various known methods can be used.

As described above, in the gear 1 according to the present embodiment, since the low elastic member 5 exists inside the tooth portion 9, the tooth portion 9 itself in which the tooth striking sound is generated can have the damping effect thereof. , The tooth-beating sound can be effectively suppressed. Further, since the low elasticity member 5 is provided so as not to be exposed from the tooth surface 9f, it is possible to suppress the decrease in the tooth surface strength due to the presence of the low elasticity member 5 inside the tooth portion 9. As a result, it is possible to prevent the strength of the gear 1 from being lowered. Therefore, it is possible to suppress the rattling noise while maintaining the strength of the gear 1.

In the gear 1, the low elasticity member 5 is arranged only inside the tooth portion 9. In this configuration, it becomes easy to maintain the strength of the gear 1.

In the gear 1, the low elasticity member 5 is provided inside all the tooth portions 9 among the plurality of tooth portions 9. With this configuration, the rattling noise can be further suppressed. Further, it becomes easy to secure the symmetry around the axis of the gear 1.

In the gear 1, the low elasticity member 5 is provided so as to be exposed from the end face 9a and the end face 9b of the tooth portion 9. In this configuration, the low elasticity member 5 can be easily filled inside the tooth portion 9 and the low elasticity member 5 can be easily provided as compared with the case where the low elasticity member 5 is not exposed at all.

A verification test on the effect of reducing the rattling noise of the gear 1 will be described. In the verification test, the gear 1 is used as Example 1, and the gear similar to that of Gear 1 except that the low elastic member 5 and the hole 11 are not provided is used as a comparative example, and the toothing noise (dB) of Example 1 and the comparative example is measured. And compared. A known measurement method was used to measure the beating sound (the same applies to the following verification test). The rotation speeds of Example 1 and Comparative Example at the time of measuring the tooth beating sound were both set to 6000 rpm. As a result of the verification test, it was confirmed that in Example 1, the rattling noise could be reduced by about 20% as compared with the comparative example.

[Second Embodiment]
The second embodiment will be described. In the description of the present embodiment, the differences from the first embodiment will be described, and duplicate description will be omitted.

As shown in FIG. 5, the gear 101 according to the second embodiment is provided with the low elasticity member 5 so as to be exposed from the top surface 9y of the tooth portion 9, and the gear 1 described above (FIG. 1). See). Each of the plurality of tooth portions 9 is provided with a hole 12 that communicates with the hole 11. The hole 12 opens in the apical surface 9y of the tooth portion 9 and extends along the radial direction. The hole 12 here is a circular hole having a smaller diameter than the hole 11. The low elasticity member 5 is further provided in the holes 12 of the plurality of tooth portions 9. The low elasticity member 5 is filled inside the hole 12 without a gap. The low elasticity member 5 is provided so as to be flush with the top surface 9y of the tooth portion 9.

In the method for manufacturing the gear 101 of the present embodiment, as shown in FIGS. 6A and 6B, a drill DR of a machine tool such as a drilling machine is used in the hole drilling process, and the hole 11 is formed in the metal member 20. After forming the hole 12, the hole 12 is formed so as to communicate with the hole 11 of the metal member 20. In the elastic member forming step, the rubber material is pushed into the holes 11 and 12 by the upper and lower dies, the rubber material is injected and filled in the holes 11 and 12, and the rubber material is vulcanized and heated. As a result, as shown in FIG. 7A, the low elasticity member 5 is formed in the holes 11 and 12 of the metal member 20. In the tooth cutting process, the tooth portion 9 including the low elasticity member 5 is such that the low elasticity member 5 is exposed from the end face 9a, the end face 9b and the top surface 9y, and the low elasticity member 5 is not exposed from the tooth surface 9f. (See FIG. 7 (b)).

As described above, even in the gear 101 according to the present embodiment, it is possible to suppress the rattling noise while maintaining its strength. Further, in the gear 101, the low elasticity member 5 is provided so as to be exposed from the top surface 9y of the tooth portion 9. In this configuration, the low elasticity member 5 can be more easily filled inside the tooth portion 9, and the low elasticity member 5 can be more easily provided.

[Modification example]
Although the embodiments have been described above, one aspect of the present invention is not necessarily limited to the above embodiments, and various changes can be made without departing from the gist thereof.

In the above embodiment, the low elasticity member 5 is provided only inside the tooth portion 9, but the low elasticity member 5 is formed inside the tooth portion 9 and the main body portion 7 as in the gear 201 shown in FIG. May be good. For example, the low elasticity member 5 may extend radially inward from the inside of the tooth portion 9 and reach the inside of the main body portion 7.

In the above embodiment, the size and range of the low elasticity member 5 are not particularly limited. For example, as in the gear 301 shown in FIG. 9, the low elasticity member 5 may be provided so that a portion exposed on the end surface 9a and the end surface 9b and a portion exposed on the top surface 9y are connected to each other. The low elasticity member 5 of the gear 301 has a plate shape and is configured to be embedded in the tooth portion 9 while being exposed to the end surface 9a, the end surface 9b, and the top surface 9y.

A verification test on the effect of reducing the rattling noise of the gear 301 will be described. Here, the gear 301 is set as the second embodiment, and the tooth striking sound (dB) of the second embodiment and the above comparative example is measured and compared. The rotation speeds of Example 2 and Comparative Example at the time of measuring the tooth beating sound were both set to 6000 rpm. As a result of the verification test, it was confirmed that in Example 2, the rattling noise could be reduced by about 10% as compared with the comparative example.

Further, for example, as in the gear 401 shown in FIG. 10, the low elasticity member 5 may extend radially inward from the gear 301 (see FIG. 9) and reach the inside of the main body 7. A verification test on the effect of reducing the rattling noise of the gear 401 will be described. Here, the gear 401 was set as Example 3, and the tooth striking sound (dB) of Example 3 and the above comparative example was measured and compared. The rotation speeds of Example 3 and Comparative Example at the time of measuring the tooth beating sound were both set to 6000 rpm. As a result of the verification test, it was confirmed that in Example 3, the rattling noise could be reduced by about 8% as compared with the comparative example.

In the above embodiment, the low elasticity member 5 is provided inside all the tooth portions 9, but the low elasticity member 5 is provided inside every N tooth portions (N is an integer of 1 or more). May be good. In this configuration, it becomes easy to maintain the strength of the gear 1. Further, it becomes easy to secure the symmetry around the axis of the gear 1. The low elasticity member 5 may be provided inside at least one of the plurality of tooth portions 9.

In the above embodiment, the low elasticity member 5 may not be exposed from at least one of the end surface 9a, the end surface 9b, and the top surface 9y of the tooth portion 9. In the above embodiment, the embodiment in which the gear 1 is a spur gear has been described as an example, but the gear 1 may be a helical gear or the like. In the above embodiment, the embodiment in which the low elasticity member 5 is formed of rubber has been described as an example, but the low elasticity member 5 is not limited to rubber. The low elastic member 5 may be a member having a lower elastic modulus than the gear body 3.

In the above embodiment, the embodiment in which the gear 1 is a metal gear has been described as an example, but the gear according to one aspect of the present invention may be a resin gear. The gear body in the resin gear includes an annular metal bush and an annular resin member provided around the metal bush and having teeth on the outer periphery. In this case, the low elastic member has a lower elastic modulus than the resin member.

Various materials and shapes can be applied to each of the configurations in the above-described embodiments and modifications, without being limited to the above-mentioned materials and shapes. Each configuration in the above embodiment or modification can be arbitrarily applied to each configuration in another embodiment or modification. A part of each configuration in the above-described embodiment or modification can be appropriately omitted without departing from the gist of one aspect of the present invention.

1,101,201,301,401 ... Gear, 3 ... Gear body, 5 ... Low elasticity member, 9 ... Tooth part, 9a, 9b ... End face, 9f ... Tooth surface, 9y ... Top surface.

Claims (5)

A gear body with multiple teeth on the outer circumference,
A gear comprising a low elastic member provided at least inside the tooth portion so as not to be exposed from the tooth surface and having a lower elastic modulus than the gear body. The gear according to claim 1, wherein the low elasticity member is arranged only inside the tooth portion. The gear according to claim 1 or 2, wherein the low elasticity member is provided inside all the tooth portions among the plurality of the tooth portions. The gear according to claim 1 or 2, wherein the low elasticity member is provided inside every N tooth portion (N is an integer of 1 or more) among the plurality of the tooth portions. The gear according to any one of claims 1 to 4, wherein the low elasticity member is provided so as to be exposed from at least one of an end surface and a top surface of the tooth portion.

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