JP2016125657A - Resin gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin gear having a built-in attenuation mechanism for impact caused by the engagement with the mating gear with a simple structure.SOLUTION: A resin gear comprises: a ring-shaped resin member 1 having teeth formed on the outer peripheral surface; a metallic bush 3 disposed in the center of the ring-shaped resin member 1; and a rubber elastic material 4 disposed between the ring-shaped resin member 1 and the metallic bush 3. On the outer peripheral surface of the metallic bush 3, a plurality of first projecting pieces 5 radially extending on the outside in a radial direction are disposed; and on the inner peripheral surface of the ring-shaped resin member 1, a plurality of second projection pieces 6 extending to the radial direction inner side are disposed. The second projecting piece 6 is positioned adjacent to the first projection piece 5; the tip of the first projecting piece 5 is slidably abutted on the inner peripheral surface of the ring-shaped resin member 1; a clearance is formed between the tip of the second projecting piece 6 and the outer peripheral surface of the metallic bush 3; and clearances formed in such a manner are filled with the rubber elastic material 4 without gaps so as to have an integral structure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin gear incorporating a damping mechanism.

  Japanese Patent Application Laid-Open No. 2001-193794 discloses a gear provided with a damping mechanism. This damping mechanism (particularly FIG. 22) is configured to include a rotating shaft and a substantially cylindrical gear arranged so as to cover the outer periphery thereof. A plurality of first projecting pieces extending radially outward in the radial direction are provided on the outer peripheral surface of the rotating shaft. A plurality of second projecting pieces extending inward in the radial direction are also provided on the inner peripheral surface of the gear. The first projecting piece and the second projecting piece are provided such that the second projecting piece is located between the first projecting pieces. With this arrangement, a damper chamber is formed between the first projecting piece and the second projecting piece, and the elastic member is accommodated in the damper chamber. Further, a gap A is formed between the elastic member housed in the damper chamber and each of the first projecting piece and the second projecting piece. Further, gaps B are also formed between the tip of the first projecting piece and the inner peripheral surface of the gear and between the tip of the second projecting piece and the outer peripheral surface of the rotating shaft.

  In the damping mechanism configured as described above, when the rotation shaft rotates relative to the gear, first, the gap A decreases with the relative rotation, and then the first protrusion or the second The projecting piece comes into contact with the elastic member. When the relative rotation amount between the rotating shaft and the gear is further increased, the elastic member is elastically deformed, and an elastic force corresponding to the magnitude of the relative rotation amount is generated. Therefore, the relative rotation between the rotating shaft and the gear is counter-biased by this elastic force.

  A technique similar to Patent Document 1 is also disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 04-054347) and Patent Document 3 (Japanese Patent Laid-Open No. 60-192145).

JP 2009-241352 A Japanese Patent Laid-Open No. 04-054347 JP-A-60-192145

  The technique disclosed in Patent Document 1 has a large number of parts / members for constituting a damping mechanism. In addition, since there are many parts and members, the number of steps for assembling the damping mechanism by attaching it to the rotating shaft is also complicated.

  The problem to be solved by the present invention is to provide a resin gear having a built-in damping mechanism for impact generated by meshing with the mating gear.

In order to solve the above-described problems, a resin gear according to the present invention includes a ring-shaped resin member having teeth formed on an outer peripheral surface, a metal bush disposed in the center of the ring-shaped resin member, and the ring. It is comprised by the rubber elastic material arrange | positioned between a resin member and a metal bush. A plurality of first protrusions radially extending outward in the radial direction are disposed on the outer peripheral surface of the metal bush, and a plurality of first protrusions extending radially inward are provided on the inner peripheral surface of the ring-shaped resin member. A second projecting piece is disposed. The first projecting piece and the second projecting piece are provided such that the second projecting piece is located between the first projecting pieces, and the tip of the first projecting piece is the inner peripheral surface of the ring-shaped resin member. A gap is formed between the tip of the second protrusion and the outer peripheral surface of the metal bush. And the rubber elastic material is filled without gaps in the gap formed between the outer peripheral surface of the metal bush, the inner peripheral surface of the ring-shaped resin member, and the outer edges of the first projecting piece and the second projecting piece, The ring-shaped resin member and the metal bush are integrated with each other through a rubber elastic material.
In the resin gear according to the present invention, in the above configuration, a gap is formed between the tip of the first protruding piece and the inner peripheral surface of the ring-shaped resin member, and the tip of the second protruding piece is a metal bush. It may be in contact with the outer peripheral surface so as to be slidable.

The resin gear according to the present invention is rotationally driven with a metal bush fixed to the rotary shaft. If the impact when the resin gear meshes with the mating gear exceeds a predetermined magnitude, the rubber elastic material is compressed between the first projecting piece and the second projecting piece and elastically deformed, and the tip of the first projecting piece And the inner peripheral surface of the ring-shaped resin member, or between the tip of the second protrusion and the outer peripheral surface of the metal bush. That is, the metal bush rotates relative to the ring-shaped resin member. The impact force generated by the elastic force at this time alleviates the impact.
Since the tip of the first projecting piece is slidably in contact with the inner peripheral surface of the ring-shaped resin member, or the tip of the second projecting piece is slidably contacted with the outer peripheral surface of the metal bush. Therefore, the ring-shaped resin member and the center of the metal bush are always kept in agreement. Also, there is a rubber elastic material interposed between the tip of the second protrusion and the outer peripheral surface of the metal bush, or between the tip of the first protrusion and the inner peripheral surface of the ring-shaped resin member. The impact in the radial direction applied to the resin gear is alleviated.

The resin gear according to the present invention can be manufactured as follows.
In other words, a rubber elastic material is filled in a gap formed between the outer peripheral surface of the metal bush, the inner peripheral surface of the ring-shaped resin member, and the outer edges of the first and second projecting pieces, and vulcanized. By doing so, the ring-shaped resin member and the metal bush are integrated with each other through the rubber elastic material. Then, teeth are formed by cutting on the outer peripheral surface of the ring-shaped resin member with reference to the center of the metal bush.

  As described above, the resin gear according to the present invention has a structure in which a ring-shaped resin member and a metal bush are integrated through a rubber elastic material, thereby incorporating a damping mechanism. . By simply mounting the resin gear on the rotating shaft, the impact damping function can be exerted, and the assembly man-hour of the damping mechanism when mounting the gear on the rotating shaft becomes unnecessary.

They are the perspective view (a) which shows embodiment of the resin-made gears concerning this invention, and the cross-sectional perspective view (b) cut | disconnected in radial direction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view (a) showing an embodiment of a resin gear according to the present invention and a cross-sectional perspective view (b) when the resin gear is cut in the radial direction.

Teeth 2 are formed on the outer peripheral surface of the ring-shaped resin member 1, and a metal bush 3 is disposed in the center of the ring-shaped resin member 1. A rubber elastic material 4 is disposed between the ring-shaped resin member 1 and the metal bush 3.
A plurality of first protrusions 5 extending radially outward in the radial direction are arranged on the outer peripheral surface of the metal bush 3. A plurality of second protrusions 6 extending inward in the radial direction are arranged on the inner peripheral surface of the ring-shaped resin member 1. In this embodiment, four first projecting pieces 5 and second projecting pieces 6 are arranged at equal angles, and the first projecting piece 5 and the second projecting piece 6 have the second projecting piece 6 as the first projecting piece. It is provided so as to be positioned between one protruding piece 5. The tip of the first protrusion 5 abuts on the inner peripheral surface of the ring-shaped resin member 1 so as to be slidable. On the other hand, there is a gap between the tip of the second protrusion 6 and the outer peripheral surface of the metal bush 3. Is formed. And the rubber elastic material 4 is a space | gap in the space | gap formed between the outer peripheral surface of the metal bush 3, the inner peripheral surface of the ring-shaped resin member 1, and the outer edge of the 1st protrusion piece 5 and the 2nd protrusion piece 6. The ring-shaped resin member 1 and the metal bush 3 are integrated via a rubber elastic material 4.

  The ring-shaped resin member 1 can be obtained by preparing a ring-shaped reinforcing fiber base as described below, and holding the resin on the ring-shaped reinforcing fiber base and molding the resin into a predetermined shape.

First, a ring-shaped short fiber aggregate is formed by using a paper compaction apparatus capable of performing papermaking and compression continuously, and the short fiber aggregate is compressed in the axial direction to form a ring-shaped reinforcing fiber. A substrate is formed. As the short fibers (fiber chops), para-aramid fibers, meta-aramid fibers, carbon fibers, glass fibers, boron fibers, ceramic fibers, ultra-high strength polyethylene fibers, polyketone fibers, polyparaphenylenebenzobisoxazole fibers, wholly aromatic At least one selected from group polyester fibers, polyimide fibers, and polyvinyl alcohol fibers can be selected, and the fiber length is preferably 2 mm to 6 mm, more preferably 3 mm. When the fiber length is less than 2 mm, the mechanical properties of the ring-shaped resin member 1 are deteriorated. On the other hand, when the fiber length exceeds 6 mm, it becomes difficult to dissociate the fiber bundle when dissociating and dispersing the fiber bundle in water during papermaking.
In addition to the above short fibers, fine fibers obtained by fibrillation of aramid fibers are included so that the freeness of the fine fibers is 100 ml or more and 400 ml or less, and the fine fiber content is 30% by mass or less of the total fibers. It is desirable to blend. As a desirable embodiment, it is preferable to mix fibrillated aramid fine fibers which are cleaved in the fiber axis direction by mechanical shearing of para-aramid fibers. When the freeness exceeds 400 ml, fibrillation is insufficient, which is not preferable for imparting strength for maintaining the shape of the ring-shaped reinforcing fiber substrate. Further, when the freeness is less than 100 ml, not only the fiber axis direction is cleaved but also the fiber is sheared in the radial direction to become a powder state, so that the entanglement of the fibers becomes worse, and the shape of the ring-shaped reinforcing fiber base material is reduced. It is not preferable in giving strength for maintaining. Preferably, 5 to 10% by mass of fibrillated fine fibers capable of imparting an appropriate strength is blended.
The ring-shaped reinforcing fiber base material may be provided with an approximately convex portion corresponding to the second protruding piece 6 at the stage of papermaking.

The ring-shaped reinforcing fiber base material is placed in a molding die, and the ring-shaped reinforcing fiber base material is impregnated and held with resin, and the ring-shaped resin member 1 is manufactured by heat and pressure molding.
As the resin, various materials such as a thermosetting resin and a thermoplastic resin can be used. For example, epoxy resin, polyaminoamide resin, phenol resin, unsaturated polyester resin, polyimide resin, polyethersulfone resin, polyetheretherketone resin, polyamideimide resin, polyamide resin, polyester resin, polyphenylene sulfide resin, polyethylene resin, polypropylene A combination of one or more resins selected from resins can be used. Among these, a polyaminoamide resin is preferable from the viewpoint of the strength and heat resistance of the cured resin.
Post-processing is performed on the molded ring-shaped resin member 1, and the shape of the second projecting piece 6 is adjusted. This is done as needed.

The ring-shaped resin member 1 manufactured as described above and a separately prepared metal bush 3 are integrated via a rubber elastic member 4.
The metal bush 3 is made of sintered metal or the like, and the rubber elastic member 4 is made of fluorine rubber, nitrile butadiene rubber, hydrogenated nitrile butadiene rubber or the like. Preferably, hydrogenated nitrile butadiene rubber is selected.
When the metal bush 3 is arranged at the center of the ring-shaped resin member 1, the first projecting piece 5 comes into contact with the inner peripheral surface of the ring-shaped resin member 1, so that the ring-shaped resin member 1 and the metal bush 3 are The center position matches. On the other hand, a gap is formed between the tip of the second projecting piece 6 and the outer peripheral surface of the metal bush 3. The first projecting piece 5 and the second projecting piece 6 are arranged so that the second projecting piece 6 is located between the first projecting pieces 5, and the outer peripheral surface of the metal bush 3 and the ring-shaped resin member 1 The rubber elastic material 4 (the material before vulcanization) is filled without gaps in the gap formed between the peripheral surface and the outer edges of the first projecting piece 5 and the second projecting piece 6. At this time, since the first projecting piece 5 is in contact with the inner peripheral surface of the ring-shaped resin member 1, the rubber elastic material does not enter the interface between the two, and the slidable state is maintained. Then, vulcanization is performed, and the ring-shaped resin member 1 and the metal bush 3 are integrated through the rubber elastic material 4.
In this embodiment, a gap is formed between the tip of the second projecting piece 6 and the outer peripheral surface of the metal bush 6, and the rubber elastic material 4 is filled in the gap. The integration between the ring-shaped resin member 1 and the metal bush 3 is strong.

  After the vulcanization, teeth 2 are formed on the outer peripheral surface of the ring-shaped resin member 1 by cutting. Since this cutting is performed with reference to the center of the metal bush 3, the ring-shaped resin member 1 and the center (axial center) of the metal bush 3 are made to be a highly accurate resin gear. be able to. Therefore, it is excellent in that a highly accurate resin gear can be obtained as compared with the embodiment in which the vulcanization process is performed after the teeth 2 are formed on the outer peripheral surface of the ring-shaped resin member 1.

  In the above embodiment, a gap is formed between the tip of the second protrusion 6 and the outer peripheral surface of the metal bush 3, and this gap is filled with the rubber elastic material 4. Instead, a gap may be formed between the tip of the first projecting piece 5 and the inner peripheral surface of the ring-shaped resin member 1, and the rubber elastic material 4 may be filled in the gap. In this case, the tip of the second projecting piece 6 abuts on the outer peripheral surface of the metal bush 3 so as to be slidable.

  The rubber elastic material 4 is filled up to the same thickness as the ring-shaped resin member 1 and the metal bush 3. In order to prevent the rubber elastic member 4 from slipping out in the axial direction of the resin gear, a slip-out preventing protrusion is projected from at least one of the inner peripheral surface of the ring-shaped resin member 1 and the outer peripheral surface of the metal bush 3, The prevention protrusions may be allowed to enter the rubber elastic material 4 in the thickness direction.

DESCRIPTION OF SYMBOLS 1 Ring-shaped resin member 2 Tooth 3 Metal bush 4 Rubber elastic material 5 1st protrusion 6 2nd protrusion

Claims (3)

A ring-shaped resin member having teeth formed on the outer peripheral surface; a metal bush disposed in the center of the ring-shaped resin member; and a rubber elastic material disposed between the ring-shaped resin member and the metal bush. Configured,
A plurality of first protrusions extending radially outward are disposed on the outer peripheral surface of the metal bush, and a plurality of first protrusions extending radially inward are provided on the inner peripheral surface of the ring-shaped resin member. The second projecting piece is disposed, and the first projecting piece and the second projecting piece are provided so that the second projecting piece is located between the first projecting pieces,
The tip of the first projecting piece slidably contacts the inner peripheral surface of the ring-shaped resin member, and a gap is formed between the tip of the second projecting piece and the outer peripheral surface of the metal bush. A space formed between the outer peripheral surface of the bush, the inner peripheral surface of the ring-shaped resin member, and the outer edges of the first projecting piece and the second projecting piece is filled with the rubber elastic material without a gap, and the ring-shaped resin A resin gear, wherein the member and the metal bush are integrated with each other through a rubber elastic material. A ring-shaped resin member having teeth formed on the outer peripheral surface; a metal bush disposed in the center of the ring-shaped resin member; and a rubber elastic material disposed between the ring-shaped resin member and the metal bush. Configured,
A plurality of first protrusions extending radially outward are disposed on the outer peripheral surface of the metal bush, and a plurality of first protrusions extending radially inward are provided on the inner peripheral surface of the ring-shaped resin member. The second projecting piece is disposed, and the first projecting piece and the second projecting piece are provided so that the second projecting piece is located between the first projecting pieces,
The tip of the second projecting piece slidably contacts the outer peripheral surface of the metal bush, and a gap is formed between the tip of the first projecting piece and the inner peripheral surface of the ring-shaped resin member. A space formed between the outer peripheral surface of the bush, the inner peripheral surface of the ring-shaped resin member, and the outer edges of the first projecting piece and the second projecting piece is filled with the rubber elastic material without a gap, and the ring-shaped resin A resin gear, wherein the member and the metal bush are integrated with each other through a rubber elastic material. A method for producing the resin gear according to claim 1 or 2,
Fill the gap formed between the outer peripheral surface of the metal bush, the inner peripheral surface of the ring-shaped resin member, and the outer edges of the first and second projecting pieces without any gaps, and vulcanize. The ring-shaped resin member and the metal bush are integrated through a rubber elastic material,
Thereafter, a tooth is formed on the outer peripheral surface of the ring-shaped resin member by cutting on the basis of the center of the metal bush, and the resin gear manufacturing method is characterized.

Images