JPS6323642Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a speed change pulley used in drive devices for automobiles, motorcycles, agricultural machinery, and other general industries, and includes a bushing in which two V-shaped pulley pieces can be rotatably moved. At the same time, by pressing each side with a spring and attaching the shaft and pulley piece in a rotational direction through each spring, power is transmitted while the belt is driven, and the drive pulley or driven pulley The purpose of this is to change the effective diameter of the speed change pulley attached to the transmission pulley by changing the distance between both shafts, adjusting the tension of the belt using a tension pulley or an idler pulley, etc.

A normal speed change pulley has a general configuration of a pair of V
The V-belt is held between variable-speed pulley pieces, and one or both pulley pieces prevent idling in the direction of rotation of the shaft due to the pressing force of the spring on the side of the belt, and one or both of the pulley pieces in the direction of thrust of the shaft. Splines or keyways are formed so that the pulley pieces can move, but splines and keyways have problems such as high material and processing costs.

The inventor of the present invention has focused on such conventional problems, conducted various studies to solve them, and has proposed several speed change pulleys. It was devised to provide an inexpensive variable speed pulley, and its feature is that both pulley pieces of a pair of V-shaped pulley pieces are connected between the shaft and an internal bushing that does not have a rotational stop such as a spline or keyway. A long-life variable speed pulley in which the end of each pulley piece and the end of the spring are integrated in the rotational direction so that the pulley can freely move in the thrust direction and rotational direction, and the effective diameter of the pulley can be freely changed. It is in.

Hereinafter, embodiments of the speed change pulley of the present invention will be described in more detail with reference to the accompanying drawings.

Figure 1 of the attached drawings shows the speed change pulley according to the present invention.
A cross-sectional view showing the normal state with the belt wrapped around it.
In the figure, reference numerals 1 and 1' indicate pulley pieces facing each other, and between these pulley pieces and the shaft 4 there are bushes 2 and 2', which are movable in the rotation direction and the thrust direction. Each locking protrusion 7, 7' provided at the end of the piece is engaged with one end of the spring 3, 3', and the other end of the spring 3, 3' is engaged with the locking protrusion 7, 7' provided at the end of each pulley piece. It engages with the locking projections 6, 6' of the flange-like stoppers 5, 5'. (See Fig. 2), the flange-like stopper 5, 5' is connected to the shaft 4 through which the pulley pieces 1, 1' are inserted.
The pulley pieces 1, 1' are fixed in the V groove formed by the pulley pieces 1, 1' with pressure applied in the thrust direction by the springs 3, 3'. It is designed to apply pressure to the inserted V-belt 8.

In the above configuration, one of the left and right springs 3, 3' is right-handed and the other is left-handed.
The winding directions are opposite to each other, and when torque is generated on the pulley, both springs always act only in the direction of unwinding.

Next, the working mechanism of the speed change pulley according to the present invention as described above will be explained. First, the V-shaped speed change pulley and the driven pulley having the above structure are wound around the V belt 8 and driven.

At this time, the V-belt 8 is normally located above between the V-shaped pulley pieces 1 and 1' as shown in FIG.
When belt 8 is rotated with initial tension and load applied,
The belt position is determined at a position that is balanced by the belt tension generated during the rotation and the pressure applied by the springs 3, 3' to the pulley pieces.

In this way, the torque generated between the side surface of the belt 8 and the pulley pieces 1, 1' is transmitted to the springs 3, 3' through the locking projections 7, 7', and further to the locking projections 6, 3' of the flange-like stoppers 5, 5'. Torque can be transmitted to the shaft 4 through the shaft 6. In addition, conversely, the pulley is arranged as follows: shaft 4 → locking projections 6, 6' → springs 3, 3' → locking projections 7, 7' → pulley piece 1,
Torque can be transmitted from 1' to belt 8. Therefore, it is possible to provide a speed change pulley that transmits power without having conventional splines or keyways.

Thus, in the present invention, as described above, each of the pair of speed change pulley pieces is made into a movable pulley piece, a rotatable bush is provided inside, and a spring is inserted between the locking protrusion of the side stopper. This has the advantage that the belt position can be set at a balanced position by the pressure from the spring, and the effective diameter of the speed change pulley can be easily changed by adjusting the belt tension. There is no need to form splines or keyways, the structure is simple, the cost is low, and it is extremely useful as an improvement over conventional speed change pulleys. Moreover, as mentioned above, in the present invention, each locking protrusion receives the pressing force from both ends of the spring, so that when torque is generated on the pulley, the spring acts only in the direction of winding and loosening, and when the load is reduced, The spring quickly returns to its original position due to the torsional repulsion force that corresponds to the amount of torsion of the spring, and has good load response.The torsional resistance force is lower than that in the tightening direction, and there is no risk of spring breakage. In addition, since both pulley pieces can be rotated, unlike moving only one, there is no problem of belt alignment, which is good.
It has the advantage of avoiding uneven wear of the belt and extending the life of the belt, and has a remarkable practical effect.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the speed change pulley for a power transmission belt according to the present invention in a normal state, and FIG. 2 is a perspective view showing details of the engaging portion of the spring end. 1, 1'...pulley piece, 2, 2'...butsu,
3, 3'...Spring, 4...Shaft, 5,
5'...stopper, 8...V belt.

Claims (1)

[Scope of utility model registration request] In a V-shaped variable speed pulley in which a pair of V-shaped pulley pieces are mounted oppositely on the shaft to change the effective diameter, each of the two opposing V-shaped pulley pieces is equipped with a pusher that can be rotated inside. The shaft rotates in the shaft rotation direction and is movable in the axial direction, and between each pulley piece and each locking protrusion of a stopper fixed to the side of each pulley piece, one side is wound clockwise and the other side is wound leftward. springs with different winding directions are inserted, and both ends of the springs are engaged with each of the movable pulley pieces and the locking protrusions of the stopper, so that when torque is generated on the pulley, the springs wind only in the direction in which they unwind. A speed change pulley for a transmission belt, characterized in that it is configured to function.