JPS6321799Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a speed change pulley for drive devices for general industry, agricultural machinery, motorcycles, automobiles, etc.
More specifically, one V-shaped pulley piece is fixed to the shaft, a spiral groove is provided on the inner surface of the other V-shaped pulley piece, and a spiral groove is provided on the outer surface of the shaft opposite to the spiral groove, and a spiral groove is provided on the outer surface of the shaft in opposition to the spiral groove. This relates to a speed change pulley in which balls are interposed at appropriate intervals in order to reduce screw resistance in spiral grooves located opposite to each other, and the movable V-shaped pulley piece is moved against the shaft by the torque generated in the belt when the belt is running, causing twisting of the spring. This causes the movable V-shaped pulley piece to move along the spiral groove in the axial direction in a direction that increases the lateral pressure against the V-belt, thereby reducing the force of the spring itself and the torsion of the spring (in the direction of decreasing the number of turns). ), etc., to increase the lateral pressure on the V-belt, and as the torque increases, the amount of twist between the shaft and the movable V-shaped pulley piece increases, and that twist increases the lateral pressure on the belt. The V-belt can run while automatically adjusting the belt side pressure according to the torque, which increases the durability of the V-belt and at the same time reduces energy consumption. It is something that you have.

In conventional speed change pulleys, the belt side pressure is usually large when running at high speeds, the belt side pressure is large when running at low speeds, and the belt side pressure is small when running at low speeds.

However, under normal conditions, the load torque is generally large at low speeds and small at high speeds.In other words, it is necessary to increase the belt side pressure when running at low speeds, and conversely reduce the side pressure at high speeds. However, in contrast, the conventional mechanism using a speed change pulley has the completely opposite effect, which not only limits the scope of use of the belt speed change mechanism. There are many problems such as lack of belt durability.

Therefore, in order to address these problems, we used a bullet that accumulates elasticity when wound tightly, and the effective diameter of the drive pulley and driven pulley automatically changes in response to changes in driving force and load. A transmission device that automatically obtains the best transmission ratio for driving force and load has been proposed in Japanese Patent Application Laid-open No. 7153/1983.

However, the variable speed pulley described in the above publication has a threaded cylindrical body attached to the shaft, a fixed pulley piece is fixed thereon, and a threaded movable pulley piece is fitted and attached along the cylindrical screw. Since it has a structure in which the sides are locked with springs, there is a drawback that when a load is applied to the pulley, the movable pulley pieces do not easily slide, making it difficult to slip and easily causing damage.

The present invention was devised to solve this problem, and the shaft is moved against the repulsive elastic force in the torsional direction of the spring in response to the torque generated on the pulley through the balls in the spiral groove inside the speed change pulley. lateral pressure is applied to the side surface of the belt by the screw thrust generated by the twisting of the movable V-shaped pulley piece.

In designing a transmission mechanism using a normal speed change pulley, the spring pressure, which is an important element in the design, has to be designed to a required spring pressure at low speeds.

In such a case, if the vehicle were to be driven at high speed under such conditions, the spring pressure would be excessive and the usable range would be extremely restricted and narrow.

On the other hand, with the method of the present invention, the belt side pressure can be adjusted almost automatically according to the torque applied to the drive device at both low and medium speeds, expanding the range of usage conditions and improving the durability of the belt. Not only that, but it also has a great effect on reducing energy consumption, and has the advantage of being applicable to a wide range of fields including general industry, agricultural machinery, motorcycles, automobiles, and others.

Hereinafter, the speed change pulley of the present invention and the transmission mechanism using the pulley 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 the transmission belt variable speed pulley according to the present invention is combined with a corresponding general fixed pulley and a V-belt is wound between both pulleys. In the figure, A indicates a variable speed pulley which is the main body of the present invention, and B indicates a fixed pulley used in combination with this pulley. Of these, the variable speed pulley consists of a pair of pulley pieces, a movable pulley piece 1 and a fixed pulley piece 2. Both of these pulley pieces 1 and 2 are fitted onto the shaft S, facing each other, and A belt 7 is held in the opposing V gap, and the movable pulley piece 1 is placed on its back so that the side surface of the V belt 7 can be pressed by the spring force of a spring 3, which will be described later. The other movable pulley piece 1 has a cylindrical part extending above the shaft S, and the inner surface of the cylindrical part cooperates with the surface of the shaft S facing it to provide a plurality of systems for each other. Spiral grooves G, g are provided, and a plurality of balls B are housed in the spiral grooves G, g, so that the ball can be slid relative to the shaft S via the balls B. It's summery.

On the other hand, on the side of the movable pulley 1, a spring retainer 5 is further attached to the end of the shaft S to hold the bolt 12.
It is fitted under positional restriction via a washer 11 attached to the shaft S, and a rotation prevention key 9 is inserted into this so that it is integrated with the shaft S.

Between the movable pulley 1 and the spring presser 5 arranged as described above, a spring 3 is interposed between the base of the cylindrical part on the side of the movable pulley and the inner surface of the spring presser 5, and one of the springs One end is attached to a protruding claw 4 of a spring rotation stopper provided on the side of the movable pulley 1, and the other end is attached to another spring rotation stopper provided on the inner surface of the spring presser 5. In the figure, the spring 3 is also attached to a protruding claw 6. They are each locked in the direction of unwinding due to the torque generated while the belt is running, and the movable pulley piece 1 as described above is pressed against the side surface of the V-belt 7.

In addition, 8 is a fixed V pulley for belt winding that corresponds to the speed change pulley, and its inner surface is connected to the shaft.
A rotation stopper key 10 is inserted between the shaft S' and the shaft S', and its extended cylindrical portion is fixed to the shaft S' by a set bolt 13.

C is the distance between the shafts of both the variable speed and fixed pulleys as described above.

Thus, the torque generated in the V-belt 7 during running is transmitted from the fixed pulley piece 2 and the movable pulley piece 1 to the spring 3 held by the stopper protrusion 4, and through the other spring-locking stopper protrusion 6 to the spring presser 5. Torque is further transmitted to the shaft S through the rotation locking key 9.

Therefore, when a load is applied to the belt 7 wound between the pulleys 7 and 7 during running, and when that torque is transmitted to the movable pulley piece 1, the torque causes the spring to twist, that is, Due to the torsion of the movable pulley piece relative to the shaft S or pulley 2, the movable pulley piece 1 moves in the axial direction via the spiral groove G and the ball B in g, depending on the balance between the torque generated on the pulley piece and the amount of torsion of the spring. , and acts to change the value of W, that is, a force acts to push the V-belt 7 up to the top surface of the pulley. However, when the distance between the shafts of the V-pulleys is fixed, the belt length As a result, since the position of the belt 7 on the pulley is fixed, the lateral pressure on the V-belt 7 inevitably increases.

The force is caused by the torque generated between the belt 7 and the movable V-shaped pulley piece 1, the spring pressure, the torsion pressure of the spring, the pressure against the side pressure of the belt, the increase in spring pressure due to the decrease in free length due to the torsion of the spring, etc. It is fixed at a certain point by balance.

That is, each balance can be adjusted by the spring constant in the compression direction of the spring, the spring constant in the torsion direction, the pitch of the spiral groove, the V-groove angle, the free length of the spring, the winding pitch, etc.
Therefore, with this method, it is possible to apply a belt side pressure that substantially corresponds to the torque.

Moreover, as mentioned above, 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 even when the load decreases, the spring It quickly returns to its original position due to the torsional repulsion force corresponding to the amount of twisting, has good load response, has less torsional resistance than the action in the tightening direction, and has no risk of spring breakage.

In addition, in a normal speed change transmission mechanism, in most cases, the torque is small at high speeds and high at low speeds.

However, with normal speed change pulleys, the belt side pressure is high at high speeds and low at low speeds, regardless of the torque, so the required spring pressure and the actual spring pressure are completely opposite, resulting in Due to the design and durability of the V-belt, as mentioned above, the range of use is limited, or the V-belt is used at the expense of a certain amount of service life.

However, in contrast, when using the variable speed pulley of the present invention, when the load torque is large and at low speeds (same as high torque at high speeds),
It has the effect of increasing the belt side pressure.In particular, the speed change pulley of the present invention has a ball inside the spiral groove, and in response to the torque generated on the pulley through the ball, it moves against the shaft against the rebound elastic force in the torsional direction of the spring. Since the screw thrust generated by the twisting of the movable V-pulley piece applies side pressure to the belt side pressure, the pitch is different from that of a screw, and the feed is smoother, so when a load is applied to the pulley. The sliding of the movable V-pulley pieces is good, reducing the chance of breakage, which naturally expands the range of uses and range of belts.Since the average belt side pressure can be lowered, the lifespan of the belt can be extended, and energy savings can be achieved. It has the advantage of being able to produce great effects in terms of aspects as well.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the normal state in which the variable speed pulley for a transmission belt according to the present invention is used in combination with a general fixed pulley, and the belt is wound between both pulleys, and Fig. 2 shows the spring shown in Fig. 1. It is a detailed perspective view of a locking part. A... Variable speed pulley, B... Fixed pulley, 1...
Movable pulley piece, 2...Fixed pulley piece, 3...Spring, 4...Movable pulley one side spring rotation stopper projection claw, 5...Spring retainer, 6
...Spring retaining side spring rotation stopper projection claw, 7...V belt, B...ball, G
...Movable pulley side spiral groove, g...Shaft side spiral groove, S...shaft.

Claims (1)

[Scope of utility model registration request] In a V-shaped variable speed pulley, in which a pair of V-shaped pulleys consisting of a fixed pulley piece and a movable pulley piece are mounted oppositely to the shaft so that their effective diameters can be changed, one fixed pulley piece is fixed to the shaft and the other A plurality of spiral grooves are provided on the inner surface of the extending cylindrical portion of the movable pulley piece facing to those of the internal shaft, and a plurality of spiral grooves are provided at predetermined positions of the spiral grooves facing each other between the shaft and the cylindrical portion of the movable pulley piece. In addition to housing the ball, the spring is secured to the spring rotation stopper protruding pawl provided between the side of the movable pulley piece having a cylindrical portion and the side of a spring retainer separately fixed to the shaft. A speed change pulley for a power transmission belt, characterized in that the pulley is interposed so that it acts only in the direction of winding and loosening due to the torque generated during running.