JPS6311421Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a speed change pulley used in drive devices for automobiles, motorcycles, agricultural machinery, and other general industries, in which one V-shaped pulley piece is equipped with a rotatable bush inside. By attaching it movably in the axial direction and pressing the side with a spring, and attaching it so that the shaft and pulley piece are connected in the rotational direction via the spring, power can be transmitted during belt drive, and the drive pulley or The purpose of this is to change the effective diameter of a variable speed pulley attached to a driven pulley by changing the distance between both shafts and adjusting belt tension using a tension pulley or an idler pulley.

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 rotational direction of the shaft due to the pressing force of the spring on the side of the belt, and one or both pulley pieces are held in the thrust direction of the shaft. Splines or key grooves are formed so that the pieces can be moved, but forming splines or key grooves in this way has problems such as high material and processing costs.

Therefore, the method described in Japanese Utility Model Application Publication No. 50-20981 has been proposed as a solution to the provision of such splines and keyways, but most of these methods do not move the spring in the tightening direction or in the tightening or loosening direction. Since the spring acts in both directions, there is a problem in that the bent portion of the spring may break if a large load is applied.

The present invention was devised to solve these conventional problems and to provide a variable speed pulley simply and inexpensively.One of the movable pulley pieces of a pair of V-shaped pulley pieces is connected to a spline or a keyway. The spring end can be freely moved in the thrust direction and rotational direction between the shaft and the internal bushing which has no locking part, and the end of the spring is held in pressure contact with the locking protrusion provided on the stepped boss part of the pulley piece. This is characterized in that the stepped boss portion of the pulley piece and the spring end are in pressure contact with each other in the direction of rotation, allowing the effective diameter of the pulley to be freely changed.

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

The figure is a cross-sectional view showing a normal state in which a V-belt is wound around a speed change pulley according to the present invention.
is one V-shaped pulley piece fixed to the shaft S by a bolt 2, and 3 is the other pulley piece attached at a position opposite to the pulley piece 1, and this pulley piece 3 rotates in the shaft rotation direction, It is a movable pulley piece that can move in the thrust direction (axial direction), and a bush 4 that can rotate together with the pulley piece 3 is installed inside the pulley piece, and a stepped boss portion 3 is provided on the outer surface of the bush 4. ' is formed. A flange-shaped stopper 6 is provided on the right side of the movable pulley piece 3 on the shaft S, and is fixed to the shaft S with bolts 7. The movable pulley 3 is configured to be able to move in the axial direction when a spring 5 having the movable pulley 3 is inserted and pressed.

In order to prevent the movable pulley piece 3 from rotating unrestrictedly, the spring 5 is held in pressure contact with the locking protrusion 9 of the stopper 6 and the stepped boss portion 3' of the movable pulley piece 3 by the locking protrusion 8 at both ends thereof. When the winding is tightened, the spring press-contact end portion rides over the locking protrusion and idles, acting only in the direction of loosening the winding.

The present invention has a simple structure as described above.Next, its working mechanism will be explained. First, when the V-shaped speed change pulley and driven pulley of the above structure are wound around the V-belt 10 and driven, the V-belt 10 Usually, V-shaped pulley pieces 1 and 3 are used as shown in the accompanying drawings.
When the V-belt 10 is placed at a certain point in between and rotated by applying initial tension and load during driving, the belt is brought to a balanced position by the pressure applied by the spring 5 to the pulley piece according to the belt tension generated during the rotation. 10 moves and its position is determined. Then, the torque generated between the side surface of the belt 10 and the pulley piece 3 is transmitted to the spring 5 through the locking protrusion 8,
Further, torque can be transmitted to the shaft S through the locking protrusion 9 of the flange stopper 6.

On the other hand, or conversely, from the shaft S there is a locking protrusion 9,
Torque can be transmitted to the spring 5, the locking protrusion 8, the pulley piece 3, and the side surface of the belt 10, and as a result, power can be transmitted without providing conventional splines or keyways.

As described above, in the present invention, a movable pulley piece is equipped with a rotatable bush, and a spring is inserted between the movable pulley piece and the stopper by pressing the locking protrusion. The belt can be moved to a balanced position, and the effective diameter of the speed change pulley can be easily changed by adjusting the belt tension.
The ends of the springs are held in pressure contact with the locking protrusions, so when the spring is tightened, the spring ends ride over the locking protrusions and spin idly, and the spring acts only in the direction of unwinding, thus creating a large load. There is no risk of spring breakage during transmission, and there is no need to form springs or keyways that are found in conventional speed change pulleys, so the structure is simple and low cost, making it an economical improvement over conventional speed change pulleys. , it is a practically extremely useful speed change pulley.

[Brief explanation of the drawing]

The figure is a cross-sectional view of the speed change pulley for a power transmission belt according to the present invention in a normal state. 1... Fixed pulley piece, 3... Movable pulley piece, 4
...Button, 5...Spring, 6...Stopper, 10...V belt, S...shaft.

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, one V-shaped variable speed pulley piece is fixedly attached to the shaft, and the other V-shaped pulley piece is fixedly attached to the shaft. A rotatably movable pusher is installed inside to rotate in the direction of rotation of the shaft and movable in the axial direction, and a spring is inserted between the movable pulley piece and a stopper fixed to one side of the pulley. A speed change pulley for a power transmission belt, characterized in that both ends are held in pressure contact with the movable pulley piece and the locking protrusion of the stopper, respectively.