JP6031867B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device, and more particularly to a power transmission device suitable for a continuously variable transmission (CVT) such as an automobile.

  Some power transmission devices such as continuously variable transmissions for automobiles include a primary pulley and a secondary pulley each having a pair of conical surface sheave surfaces, and a power transmission chain wound around both pulleys.

  As a power transmission chain, a chain including a plurality of links and a plurality of first pins and a plurality of second pins that connect these links so as to be bent is known (Patent Document 1). In the power transmission device including such a power transmission chain, the first pin is sandwiched between the pair of sheave surfaces of the pulley, and the power is transmitted by the force between the both end surfaces of the first pin and each sheave surface. Power is transmitted between the chain and the pulley.

JP 2011-69411 A

  According to the power transmission device of Patent Document 1, when the power transmission chain is broken, the broken power transmission chain may move to the outer diameter side of the pulley and come into contact with the housing vigorously. In this case, the broken power transmission chain may break through the housing or be pinched between the pulley and the housing, thereby obstructing (locking) the rotation of the pulley.

  An object of the present invention is to prevent the broken power transmission chain from coming into contact with the housing vigorously, thereby preventing the housing from being pierced or the rotation of the pulley being locked.

The power transmission device according to the present invention includes a pair of pulleys, a power transmission chain wound around the pair of pulleys, and a housing that houses at least a part of the pair of pulleys and the power transmission chain. The power transmission chain includes a plurality of links, a plurality of first pins and a plurality of second pins that connect the plurality of links so as to be bendable to each other, and at least one of the first pins and the second pins pins are adapted to be held between the sheave surfaces of a pair of said pulleys, the radially outward end portion of each of the pulleys, the sheave surface than the sheave surface of the outer diameter side end portion A restricting portion is provided that restricts the movement of the power transmission chain to the outer diameter side end portion of the pulley , which is disposed so as to protrude inside .

  According to the power transmission device of the present invention, it is possible to suppress the broken power transmission chain from coming into contact with the housing vigorously, thereby suppressing the housing from being pierced or the pulley rotation being locked. .

FIG. 1 is a side view showing a first embodiment of a power transmission device according to the present invention. FIG. 2 is a front view of FIG. FIG. 3 is a plan view showing a part of one embodiment of a power transmission chain used in the power transmission device. FIG. 4 is an enlarged side view of the link and the pin. FIG. 5 is a front view showing a second embodiment of the power transmission device according to the present invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 show a first embodiment of a power transmission device according to the present invention.

  As shown in FIGS. 1 and 2, the power transmission device (1) includes a pair of pulleys (2), a power transmission chain (3) wound around both pulleys (2), and a pair of pulleys ( 2) and a housing (4) for housing at least a part of the power transmission chain (3).

  As shown in FIG. 2, each pulley (2) includes a fixed sheave (2a) fixed to the pulley shaft (2e) and a movable sheave (2b) supported on the pulley shaft (2e) so as to be movable in the axial direction. And. The fixed sheave (2a) and the movable sheave (2b) have conical face-like sheave surfaces (2c) and (2d) that face each other.

  As shown in detail in FIGS. 3 and 4, the power transmission chain (3) includes a plurality of links (11), a plurality of first pins (14) and a plurality of first pins (14) that connect the plurality of links (11) together. The second pin (15).

  The link (11) has a front through hole (12) located on the front side in the chain traveling direction and a rear through hole (13) located on the rear side in the chain traveling direction.

  As shown in FIG. 4, the front through-hole (12) includes a rear first pin insertion portion (16) and a front second pin insertion portion (17). A first pin (14) is movably fitted to the first pin insertion portion (16). The second pin (15) is fixed to the second pin insertion portion (17).

  The rear through hole (13) includes a rear first pin insertion portion (18) and a front second pin insertion portion (19). The first pin (14) is fixed to the first pin insertion portion (18). A second pin (15) is movably fitted in the second pin insertion part (19).

  The links (11) are overlapped so that the front through-hole (12) of one link (11) on the rear side in the traveling direction and the rear through-hole (13) on the other link (11) on the front side in the traveling direction correspond to each other. ing. Each first pin (14) and each second pin (15) are fitted into a plurality of front through holes (12) and rear through holes (13) overlapping in the chain width direction.

  The first pin (14) and the second pin (15) are relatively rolled and brought into contact with each other, whereby the links (11) can be bent. The locus of the contact position between the first pin (14) and the second pin (15) with respect to the first pin (14) is an involute of a circle. In this embodiment, the rolling contact surface (14a) of the first pin (14) is an involute curve, and the rolling contact surface (15a) of the second pin (15) is a flat surface (the cross-sectional shape is a straight line). Yes.

  In FIG. 4, positions A and B are lines (dots in the cross section) where the first pin 14 and the second pin 15 are in contact with each other in the straight part of the chain 3 and the distance between AB. Is the pitch.

  The pulley (2) is made of alloy steel for machine structure, steel for carburizing, or the like. The link (11) is made of, for example, spring steel or carbon tool steel. The material of the link (11) is not limited to spring steel or carbon tool steel, but may of course be other steel such as bearing steel. In the link (11), the front and rear insertion parts (12) and (13) may be independent through holes (links with columns), and the front and rear insertion parts (12) and (13) have one through hole (no columns). Link). As the material of the first pin (14) and the second pin (15), appropriate steel such as bearing steel is used.

  Both end surfaces of the first pin (14) are sandwiched between a pair of opposed sheave surfaces (2c) (2d) of the pulley (2), and both end surfaces of the first pin (14) and each sheave surface (2c) ) (2d), the power is transmitted between the power transmission chain (3) and the pulley (2). The movable sheave (2b) is pressed to the fixed sheave (2a) side by a hydraulic actuator (not shown), so that a clamping force for clamping the power transmission chain (3) is applied to the pulley (2). It is done.

  The inclination angle of the sheave surfaces (2c) and (2d) of the pulley (2) is normally 11 °. Correspondingly, both side surfaces of the power transmission chain (3) (both end surfaces of the first pin (14)) are also formed to have an inclination angle of 11 °.

  In FIG. 2, when the movable sheave (2b) of the pulley (2) is moved toward or away from the fixed sheave (2a), the winding diameter of the power transmission chain (3) in the pulley (2) is large when approaching, It becomes smaller at the time of separation.

  In the pair of pulleys (2) not shown in FIG. 2, the fixed sheave is opposite to the fixed sheave (2a) shown in the figure, with the power transmission chain (3) in between and the opposite side in the axial direction. Is arranged. The movable sheave moves in the opposite direction to the movable sheave (2b) of the pulley (2) shown. As a result, the gear ratio of the power transmission device (1) changes steplessly.

  As shown in FIG. 2, the fixed sheave (2a) of the pulley (2) and the outer diameter side ends (2f) (2g) of the movable sheave (2b) are vertical surfaces. At the outer diameter side ends (2f) (2g) of the sheaves (2a) (2b), annular rubber regulating members (21) (22) are provided. The regulating members (21) and (22) have a square cross section and are integrated with the fixed sheave (2a) and the movable sheave (2b) by vulcanization adhesion. The restricting members (21) and (22) are arranged so as to protrude inward from the sheave surfaces (2c) and (2d) at the outer diameter side end.

  In a state where the fixed sheave (2a) and the movable sheave (2b) are closest, the restriction member (21) provided on the fixed sheave (2a) and the restriction member (22) provided on the movable sheave (2b) The inner method is slightly smaller than the length of the first pin (14). Therefore, in this state, if the power transmission chain (3) tries to move from the position indicated by the solid line in FIG. 1 upward (in the radial direction of the pulley (2)) indicated by the two-dot chain line, the first pin ( The both end surfaces of 14) and the restricting members (21) and (22) exert a frictional force by contacting each other.

  According to the power transmission device (1) of the first embodiment, when the broken power transmission chain (3) moves in the outer diameter direction of the pulley (2), the power transmission chain (3) is connected to each regulating member (21). Since a frictional force is received in contact with (22), the force in the moving direction is reduced. That is, the restricting members (21) and (22) restrict the movement of the broken power transmission chain in the pulley outer diameter direction. Therefore, the energy when the power transmission chain (3) collides with the housing (4) can be reduced. That is, it is possible to suppress the power transmission chain (3) from coming into contact with the housing (4) vigorously. Therefore, there is a possibility that the broken power transmission chain (3) may break through the housing (4) or be pinched between the housing (4) and the pulley (2) and the pulley (2) cannot be rotated. Decrease.

  FIG. 5 shows a second embodiment of the power transmission device according to the present invention.

  In FIG. 5, annular recesses (23) and (24) are formed in the vertical surfaces of the outer diameter side ends (2f) and (2g) of the fixed sheave (2a) and the movable sheave (2b) of the pulley (2). O-rings (25) and (26) as restricting members are fitted in the recesses (23) and (24), respectively. The O-rings (25) and (26) have a circular cross section and are made of rubber. The O-rings (25) and (26) are arranged so as to protrude inward from the sheave surfaces (2C) and (2D) at the outer diameter side end.

  In the state where the fixed sheave (2a) and the movable sheave (2b) are closest, the inner method of one O-ring (25) and the other O-ring (26) is more than the length of the first pin (14). It has been made slightly smaller. Therefore, in this state, if the power transmission chain (3) moves from the position indicated by the solid line in FIG. The both end faces of 14) and the O-rings 25 and 26 are brought into contact with each other to exert a frictional force.

  According to the power transmission device (1) of the second embodiment, when the broken power transmission chain (3) is detached from the pulley (2), the power transmission chain (3) contacts the O-rings (25) and (26). Since the frictional force is received, the force in the moving direction is reduced. Therefore, the energy when the power transmission chain (3) collides with the housing (4) can be reduced. That is, it is possible to suppress the power transmission chain (3) from coming into contact with the housing (4) vigorously. Therefore, there is a possibility that the broken power transmission chain (3) may break through the housing (4) or be pinched between the housing (4) and the pulley (2) and the pulley (2) cannot be rotated. Decrease.

  In each of the above embodiments, the restricting members (21), (22), (25) and (26) may be made of a softer material than the first pin (14). An elastic body such as a metal or a metal (for example, aluminum) may be used. Further, the shapes of the regulating members (21), (22), (25), and (26) are not limited to those of the above-described embodiment, and can be changed as appropriate.

(1): Power transmission device, (2): Pulley, (2a): Fixed sheave, (2b): Movable sheave, (2c) (2d): Sheave surface, (3): Power transmission chain, (11): Link, (14): 1st pin, (15): 2nd pin, (21) (22): Restriction member (regulation part), (25) (26): O-ring (regulation part)

Claims (2)

A pair of pulleys, a power transmission chain wound around the pair of pulleys, and a housing that houses at least a part of the pair of pulleys and the power transmission chain;
The power transmission chain includes a plurality of links, and a plurality of first pins and a plurality of second pins that connect the plurality of links in a bendable manner.
At least one of the first pin and the second pin is sandwiched between a pair of sheave surfaces of each pulley;
Wherein the outer diameter side end portion of each of the pulleys, than the sheave surface of the outer diameter side end portion are arranged protruding inside between the sheave surfaces, said outside diameter side end portion in said pulley A power transmission device provided with a restriction portion for restricting movement of the power transmission chain. The power transmission device according to claim 1, wherein the restricting portion is formed of an elastic body.

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