JPH08219258A - Pulley structure of continuously variable transmission - Google Patents

Abstract

PURPOSE: To provide a pulley structure of a continuously variable transmission where no special machining is required on a rotary shaft. CONSTITUTION: A plurality of groove parts 15-15 are formed in the circumferential direction of an outer circumferential part of a rotary shaft 1 with appropriate intervals, a key 16 formed of the material of small coefficient of friction is fitted to each groove part 15, and a longitudinal groove part with which each key 16 is engaged is formed on the inner circumference of a sliding cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulley structure for a continuously variable transmission.

[0002]

2. Description of the Related Art FIG. 4 shows a pulley structure of a conventional continuously variable transmission.
And FIG. 5 will be described. FIG. 4 shows a half cross-section of a fixed pulley and a movable pulley that constitute a pulley of a continuously variable transmission, and FIG. 5 shows a cross-sectional view taken along the line AA of FIG. In the figure, a rotary shaft 1 driven to rotate by an engine (not shown) has a transmission main body 4 by bearings 2 and 3.
Is supported by. A fixed pulley 5 is integrally formed on the rotary shaft 1 so as to project outward, and a plurality of tooth portions 6 are formed on the outer periphery of the rotary shaft 1 so as to project outward. 6 are formed. These tooth portions 6 to 6 are provided on the outer circumference of the rotary shaft 1 at equal intervals in the circumferential direction.

The movable pulley 7 integrally has a slide cylinder portion 8 which is slidable along the rotary shaft 1 on the opposite side of the fixed pulley 5 and can be moved in and out of contact with the fixed pulley 5. A plurality of longitudinal groove portions 8a to 8a into which the tooth portions 6 to 6 are fitted are formed on the inner peripheral surface of the slide cylinder portion 8 at corresponding intervals. In the figure, 9 is a V-belt that is mounted between the fixed pulley 5 and the movable pulley 7.

A spacer 10 is press-fitted into the inner periphery of the rear end of the slide cylinder 8 and the pulley bush 1 is attached to the inner periphery of the spacer 10 and the inner periphery of the front end of the slide cylinder 8.
1 and 12 are press-fitted, respectively. These pulley bushes 11 and 12 are in sliding contact with the rotating shaft 1 to regulate the radial position of the movable pulley 7.

In such a pulley structure, the teeth 6 to 6 on the outer circumference of the rotary shaft 1 and the grooves 8a to 8a on the inner circumference of the slide cylinder 8 are provided.
In order to reduce the frictional force between and, as shown in FIG. 6, a recessed fitting portion 13 is formed on the outer peripheral portion of each tooth portion 6 facing the corresponding groove portion 8a, and the fitting portion 13 has a cross section. A structure has been proposed in which a chip material 14 formed of a material having a substantially U shape and a small friction coefficient is fixed by an adhesive or the like.

[0006]

However, in the structure in which the chip material 14 is fixed to the fitting portion 13 of each tooth portion 6 as described above, the groove processing for forming the fitting portion 13 on each tooth portion 6 is performed. However, there is a drawback that such processing is difficult and the processing cost is high.

[0007]

In order to solve the above problems, the present invention provides a fixed pulley which rotates integrally with a rotary shaft,
A pulley structure of a continuously variable transmission having a movable pulley provided with a slide cylinder that is slidable in the axial direction and capable of following and rotating with respect to the rotary shaft, wherein the outer peripheral portion of the rotary shaft is appropriately circumferentially arranged. A plurality of grooves are formed at intervals, and each of the grooves is fitted with a key formed of a material having a small coefficient of friction, while the inner circumference of the slide cylinder is a circle in which the key is received. A groove portion having a width in the circumferential direction and extending in the axial direction,
It is characterized in that a plurality of grooves are formed at intervals corresponding to the grooves of the outer peripheral portion of the rotating shaft.

[0008]

In the present invention, since the key for reducing the friction with the groove of the slide cylinder is fitted in the groove of the rotary shaft, special processing is required for the rotary shaft like the conventional pulley structure. There is no need to do it.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The basic structure of this embodiment is the same as that of the above-mentioned conventional example, and the same members are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 1, a groove portion 15 is formed in the step portion 1a formed on the outer periphery of the rotary shaft 1 by recessing it in the shape of an elongated hole in the longitudinal direction on the outer periphery thereof. As shown in FIG. 2 corresponding to FIG. 5, it is provided at three locations at equal intervals in the circumferential direction. Each groove 15 has a key 1
6 is fitted and the key 16 is formed of a material having a small friction coefficient. Examples of such a material include a material in which polyimide (PI), tetrafluoroethylene (PTFE) and graphite are mixed, Alternatively, a material obtained by mixing polyether ether ketone (PEEK), carbon fiber (CF) and tetrafluoroethylene (PTFE) is preferable.

Grooves 19 to 19 formed at three locations on the inner circumference of the slide cylinder portion 8 corresponding to the respective groove portions 15 have a width in the circumferential direction capable of receiving the key 16, respectively. The side surface of the key 16 is capable of sliding contact with the circumferential side surface of each groove portion 19.

In addition, in the mounted state, the gap between the upper surface of the key 16 and the bottom surface of the groove portion 19 of the slide cylinder 8, and further the gap between the stepped portion 1a and the inner peripheral surface of the slide cylinder 8 facing this. Is the pulley bush 1 described above in the prior art.
It is set to be larger than the gap between the rotary shafts 1 and 12 and the rotary shaft 1, so that the load in the radial direction is not applied to the key 16 or the groove portion 15.

In the present embodiment, the key 16 can surely fix the relative position with respect to the groove portion 15 without forming the recessed fitting portion 13 or the like on the tooth portion 6 as in the conventional example, so that the groove portion 15 can be fixed.
It is possible to easily process the rotating shaft 1 including the above and to reduce the manufacturing cost.

Further, the movement of the movable pulley 7 with respect to the fixed pulley 5 for changing the pulley interval, that is, the sliding of the slide cylinder portion 8 with respect to the rotating shaft 1, causes low friction due to the sliding contact between the side surface of the key 16 and the side surface of the groove portion 19. Done in the state.

Further, the rotation of the rotary shaft 1 can be surely transmitted to the slide cylinder portion 8 and the movable pulley 7 by the contact between the side surface of the key 16 and the side surface of the groove portion 19.

[0016]

According to the present invention, the key material for reducing the frictional force can surely fix the relative position with respect to the groove portion without forming a fitting portion in the tooth portion as in the conventional case, so that the rotary shaft including the groove portion can be fixed. Can be easily processed and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing a pulley structure of a continuously variable transmission according to an embodiment of the present invention, and is an exploded perspective view of essential parts showing attachment of a friction reducing key to a groove of a rotary shaft.

FIG. 2 is a cross-sectional view showing a fitted state of a slide cylinder with respect to the rotary shaft shown in FIG.

FIG. 3 is a plan view showing how the key shown in FIG. 1 is attached to a rotary shaft.

FIG. 4 is an axial half sectional view of a pulley structure of a conventional continuously variable transmission.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is an exploded perspective view showing a conventional attachment structure of a friction reducing chip material to a tooth portion of a rotary shaft.

[Explanation of symbols]

 1 rotary shaft 5 fixed pulley 7 movable pulley 8 slide cylinder 15 groove 16 key 19 groove

Claims (1)

[Claims] 1. A fixed pulley that rotates integrally with a rotating shaft,
A pulley structure of a continuously variable transmission having a movable pulley provided with a slide cylinder that is slidable in the axial direction and capable of following and rotating with respect to the rotary shaft, wherein the outer peripheral portion of the rotary shaft is appropriately circumferentially arranged. A plurality of grooves are formed at intervals, and each of the grooves is fitted with a key formed of a material having a small coefficient of friction, while the inner circumference of the slide cylinder receives a circle in which the key is received. A groove portion having a width in the circumferential direction and extending in the axial direction,
A pulley structure for a continuously variable transmission, wherein a plurality of pulley structures are formed at intervals corresponding to the grooves on the outer peripheral portion of the rotary shaft.