JP2007192334A - Power transmission mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission mechanism for reducing the number of part items of a driven rotary member, for easily radiating heat of from a bearing compared to a power transmission mechanism of a patent document 1. <P>SOLUTION: This power transmission mechanism has a resin pulley rotatably supported by a housing of a rotary apparatus via the bearing and connected to an external driving source via an endless belt, and the driven rotary member joined to the pulley and a main shaft of the rotary apparatus and transmitting rotation of the pulley to the main shaft of the rotary apparatus. The pulley has a driven rotary member joining part and a bearing locking part. The driven rotary member joining part and the bearing locking part are a metallic integral part. The driven rotary member joining part has a torque cutoff mechanism of cutting off the transmission of torque when the torque transmitted to the driven rotary member from the pulley exceeds a predetermined value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission mechanism.

The pulley of the rotating device is supported by a housing of the rotating device through a bearing and rotatably connected to an external driving source through an endless belt, and the pulley and the rotating device main shaft are coupled to the rotation of the pulley. The outer ring of the bearing and the pulley are integrally formed by insert molding, and the driven rotating member is a torque that interrupts the torque transmission when the torque transmitted from the pulley to the driven rotating member exceeds a predetermined value. A power transmission mechanism having a shut-off mechanism is disclosed in Patent Document 1.
JP 2003-035321 A

The power transmission mechanism of Patent Document 1 has the following problems.
1. When the bearing and the resin pulley are integrally formed, the heat conductivity of the resin is smaller than that of the metal, so that it is difficult to dissipate the heat generated by the bearing, and the durability of the bearing is reduced.
2. Since the torque cut-off mechanism is disposed on the driven rotating member, the number of parts of the driven rotating member is large and the manufacturing cost is high.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a power transmission mechanism in which heat generation from a bearing is easily radiated and the number of parts of a driven rotating member is small compared to the power transmission mechanism of Patent Document 1. To do.

In order to solve the above-mentioned problem, in the present invention, a resin pulley that is rotatably supported by a housing of a rotating device via a bearing and connected to an external drive source via an endless belt, a pulley, and a main shaft of the rotating device And a driven rotation member that transmits rotation of the pulley to the main shaft of the rotating device, and the pulley has a driven rotation member coupling portion and a bearing locking portion, and the driven rotation member coupling portion and the bearing locking The part is a metal integrated part, and the driven rotary member coupling part has a torque cutoff mechanism that cuts off torque transmission when the torque transmitted from the pulley to the driven rotary member exceeds a predetermined value. A power transmission mechanism is provided.
In the power transmission mechanism according to the present invention, since the bearing is locked to the resin pulley via the metal bearing locking portion, the heat generated in the bearing is radiated through the metal bearing locking portion. Can do. Therefore, the durability of the bearing does not decrease. Since the torque shut-off mechanism is disposed in the driven rotary member coupling portion of the pulley, the driven rotary member has a small number of parts and a low manufacturing cost. By making the driven rotating member coupling part and the bearing locking part as an integral part, the number of parts can be reduced as compared with the case where both parts are separate parts.

In a preferred embodiment of the present invention, the resin pulley and the metal integrated part are integrally formed by insert molding.
The metal integrated part and the resin pulley formed of the driven rotating member coupling part and the bearing locking part are integrally formed by insert molding, so that the metal integrated part can be firmly coupled to the resin pulley. .

In a preferred embodiment of the present invention, a concave portion or a convex portion is formed in a contact portion between the bearing locking portion and the resin pulley.
By forming the concave portion or the convex portion in the contact portion of the bearing locking portion with the resin pulley, the connection between the resin pulley after the insert molding and the metal integrated part is further strengthened. As a result, the coupling between the resin pulley and the metal integral part breaks before the torque shut-off mechanism is activated, and a slip occurs between the metal integral part and the resin pulley and the torque transmission is interrupted. Occurrence of the situation is prevented, and torque interruption by the torque interruption mechanism is ensured.

In a preferred aspect of the present invention, the torque interrupting mechanism is a fragile portion formed in the driven rotating member coupling portion.
By using the torque interrupting mechanism as a weak part formed in the driven rotating member coupling part, the configuration of the torque interrupting mechanism can be simplified.

In a preferred embodiment of the present invention, the metal integral part is made of sintered metal.
By manufacturing the metal integral part with sintered metal, the manufacturing cost can be reduced even with a complicated shape.

In a preferred aspect of the present invention, the metal integral part is surface-treated before insert molding.
Before insert molding, the metal integrated part is subjected to metal plating treatment such as galvanization, chrome plating, nickel plating, etc., coating treatment such as cation painting, anion painting, etc. Corrosion resistance can be improved.

In the preferable aspect of this invention, the end surface of the bearing latching | locking part is exposed outside.
By exposing the end face of the bearing locking portion to the outside, the heat generated in the bearing is effectively radiated to the outside, and the durability of the bearing is improved.

In a preferred embodiment of the present invention, the coupling portion between the driven rotating member and the pulley is a leaf spring.
If the coupling portion of the driven rotating member with the pulley is a leaf spring, when the fragile portion formed in the driven rotating member coupling portion is broken and the torque transmission is interrupted, the broken piece of the coupling portion coupled to the leaf spring is the plate. As the spring returns, it is quickly separated from the broken piece of the coupling portion connected to the pulley, so that it is possible to avoid the generation of abnormal noise and the occurrence of unpleasant torque shock due to the interference of both broken pieces.

In a preferred aspect of the present invention, when the torque transmission is interrupted, the leaf spring returns toward the driven rotating member along the main shaft of the rotating device and leaves the pulley.
When the weakened portion formed in the driven rotating member coupling portion is broken and the torque transmission is interrupted, the leaf spring returns to the driven rotating member direction along the main axis of the rotating device, and is coupled to the leaf spring by moving away from the pulley. It is possible to reliably avoid interference between the broken part of the coupling part and the broken part of the coupling part coupled to the pulley.

In the power transmission mechanism according to the present invention, since the bearing is locked to the resin pulley via the metal bearing locking portion, the heat generated in the bearing is radiated through the metal bearing locking portion. Can do. Therefore, the durability of the bearing does not decrease. Since the torque shut-off mechanism is disposed in the driven rotary member coupling portion of the pulley, the driven rotary member has a small number of parts and a low manufacturing cost. By making the driven rotating member coupling part and the bearing locking part as an integral part, the number of parts can be reduced as compared with the case where both parts are separate parts.

A power transmission mechanism according to an embodiment of the present invention will be described.
As shown in FIGS. 1 to 3, the power transmission mechanism A is made of a resin that is rotatably supported by a housing 100 of a rotating device via a bearing 101 and connected to an external drive source (not shown) via an endless belt (not shown). The pulley 1 and the driven rotating member 2 coupled to the pulley 1 and the main shaft 102 of the rotating device and transmitting the rotation of the pulley 1 to the main shaft 102 of the rotating device are provided.

The pulley 1 has a driven rotating member coupling portion 3 and a bearing locking portion 4. The driven rotating member coupling portion 3 and the bearing locking portion 4 are an integral part made of sintered metal. The resin pulley 1 and the sintered metal integral part are integrally formed by insert molding. Prior to insert molding, the sintered metal integrated part is subjected to a surface treatment by applying a metal plating process such as galvanizing, chrome plating or nickel plating, or a coating process such as cation coating or anion coating. The driven rotation member coupling portion 3 includes a plurality of female screw portions 3 a and a radiating arm-shaped weak portion 3 b that connects the female screw portion 3 a to the bearing locking portion 4. The bearing locking portion 4 is a ring-shaped member, and the outer ring of the bearing 101 is press-fitted and fixed. Both end surfaces of the bearing locking portion 4 are exposed to the outside.
The driven rotating member 2 has a plurality of leaf springs 5. The leaf spring 5 is elastically deformed and has one end screwed to the driven rotating member 2 and the other end screwed to the female screw portion 3 a of the driven rotating member coupling portion 3.

The power transmission mechanism A transmits the rotational power of the external drive source to the main shaft 102 of the rotating device via the pulley 1, the leaf spring 5, and the driven rotation member 2.
When the torque transmitted from the pulley 1 to the driven rotating member 2 exceeds a predetermined value, the fragile portion 3b of the driven rotating member coupling portion 3 is broken and the torque transmission from the pulley 1 to the driven rotating member 2 is interrupted. As shown in FIG. 4, when the weakened portion 3b formed in the driven rotating member coupling portion 3 is broken and the torque transmission is interrupted, the leaf spring 5 returns to the driven rotating member 2 along the main shaft 102 of the rotating device. Then, move away from the resin pulley 1.

In the power transmission mechanism A, since the bearing 101 is locked to the resin pulley 1 via the metal bearing locking portion 4, the heat generated by the bearing 101 is radiated through the metal bearing locking portion 4. can do. Therefore, the durability of the bearing 101 is not lowered. Since the fragile portion 3b, which is a torque interruption mechanism, is disposed in the driven rotation member coupling portion 3 of the pulley, it is not necessary to provide the torque interruption mechanism in the driven rotation member 2. Therefore, the driven rotating member 2 has a small number of parts and a low manufacturing cost. By making the driven rotating member coupling part 3 and the bearing locking part 4 as an integral part, the number of parts is reduced as compared with the case where both parts are separate parts.

The metal integrated part composed of the driven rotating member coupling part 3 and the bearing locking part 4 and the resin pulley 1 are integrally formed by insert molding, whereby the metal integral part is firmly coupled to the resin pulley. ing.
By using the weakening part 3b formed in the driven rotating member coupling part 3 as the torque interruption mechanism, the configuration of the torque interruption mechanism is simplified.
By making a metal integral part with sintered metal, the manufacturing cost is reduced even in a complicated shape.
By surface-treating the metal integrated part before insert molding, the corrosion resistance of the metal integrated part is improved.

By exposing the end face of the bearing locking portion 4 to the outside, the heat generated by the bearing 101 is effectively radiated to the outside, and the durability of the bearing 101 is improved.
Since the coupling portion of the driven rotating member 2 with the resin pulley 1 is a leaf spring 5, as can be seen from FIG. 4, when the fragile portion 3b formed in the driven rotating member coupling portion 3 is broken and the torque transmission is interrupted, The broken piece of the coupling portion 3 coupled to the leaf spring 5 is quickly separated from the broken piece of the coupling portion 3 coupled to the resin pulley 1 as the leaf spring 5 returns. As a result, it is possible to avoid the generation of abnormal noise and the occurrence of unpleasant torque shock due to the interference between both broken pieces.
When the fragile portion 3b formed in the driven rotating member coupling portion 3 is broken and the torque transmission is interrupted, the leaf spring 5 returns to the driven rotating member 2 along the main shaft 102 of the rotating device and separates from the resin pulley 1. Accordingly, it is possible to reliably avoid interference between the broken piece of the coupling portion 3 coupled to the leaf spring 5 and the broken fragment of the coupling portion 3 coupled to the resin pulley 1.

On the outer peripheral surface of the bearing locking portion 4 that is the contact portion of the bearing locking portion 4 with the resin pulley 1, a spiral groove, a single or a plurality of grooves extending in the axial direction, a single or a plurality of recesses, and a spiral protrusion A single or a plurality of protrusions extending in the axial direction, a single or a plurality of protrusions, or the like may be formed.
By forming a concave portion or a convex portion on the outer peripheral surface of the bearing locking portion 4 that is a contact portion of the bearing locking portion 4 with the resin pulley 1, the driven rotating member coupling portion 3 and the bearing locking after the insert molding are formed. The connection between the metal integrated part composed of the portion 4 and the resin pulley 1 is further strengthened. As a result, before the fragile portion 3b breaks, the coupling between the resin pulley 1 and the metal integral part breaks down, and slip occurs between the metal integral part and the resin pulley 1 so that torque transmission is interrupted. Is prevented, and torque interruption due to breakage of the fragile portion 3b is secured.

The present invention relates to a resin pulley that is rotatably supported by a housing of a rotating device via a bearing and connected to an external drive source via an endless belt, and is coupled to a pulley and a main shaft of the rotating device to rotate the pulley. It can be widely used in a power transmission mechanism including a driven rotating member that transmits to the main shaft of a rotating device and a torque blocking mechanism that blocks torque transmission when the torque transmitted from the pulley to the driven rotating member exceeds a predetermined value. .

It is sectional drawing of the power transmission mechanism which concerns on the Example of this invention. It is an II-II arrow line view of FIG. It is the III-III arrow line view of FIG. It is sectional drawing of the power transmission mechanism which concerns on the Example of this invention.

Explanation of symbols

A power transmission mechanism 1 pulley 2 driven rotating member 3 driven rotating member coupling portion 3a screw portion 3b weakened portion 4 bearing locking portion 5 leaf spring 100 housing 101 bearing 102 main shaft

Claims (9)

The pulley of the rotating device is supported by a housing of the rotating device through a bearing and rotatably connected to an external driving source through an endless belt, and the pulley and the rotating device main shaft are coupled to the rotation of the pulley. The pulley includes a driven rotation member coupling portion and a bearing locking portion, and the driven rotation member coupling portion and the bearing locking portion are metal integrated parts, and the driven rotation member The power transmission mechanism, wherein the coupling portion has a torque cutoff mechanism that cuts off torque transmission when the torque transmitted from the pulley to the driven rotating member exceeds a predetermined value. The power transmission mechanism according to claim 1, wherein the resin pulley and the metal integrated part are integrally formed by insert molding. The power transmission mechanism according to claim 2, wherein a concave portion or a convex portion is formed in a contact portion between the bearing locking portion and the resin pulley. The power transmission mechanism according to any one of claims 1 to 3, wherein the torque interrupting mechanism is a fragile portion formed in the driven rotating member coupling portion. The power transmission mechanism according to any one of claims 1 to 4, wherein the metal integrated part is made of sintered metal. The power transmission mechanism according to claim 2 or 3, wherein the metal integrated part is surface-treated before insert molding. The power transmission mechanism according to claim 1, wherein an end surface of the bearing locking portion is exposed to the outside. The power transmission mechanism according to claim 4, wherein the coupling portion between the driven rotating member and the pulley is a leaf spring. 9. The power transmission mechanism according to claim 8, wherein when the torque transmission is interrupted, the leaf spring returns toward the driven rotating member along the main shaft of the rotating device and leaves the pulley.

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