JPH038416B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a variable speed pulley, and more particularly to a centrifugal thrust type variable speed pulley that utilizes centrifugal force. (Prior art) Variable speed V-pulleys that utilize centrifugal force have been widely known, and are disclosed in Japanese Patent Publication No. 51-6815 and Japanese Patent Application Laid-Open No. 1983-1989.
-47064 Publication, Japanese Patent Application Laid-Open No. 51-54158, Jitsukiaki
Some examples are shown in Japanese Utility Model Application No. 47-22065 and Japanese Utility Model Application Publication No. 51-58269. For example, in a variable speed pulley consisting of a fixed V-pulley piece and a movable V-pulley piece, as typified by Japanese Patent Publication No. 51-6815, the movable V-pulley piece has a shroud plate on the back side and rotates inside. It is constructed by housing a weight that moves by centrifugal force to move the movable V-pulley piece in the axial direction relative to the fixed V-pulley piece and change the effective diameter of the pulley. Steel balls are used, and usually a radial guide is attached, and each ball is inserted into this guide so that the ball moves in the radial direction along the guide groove as the pulley rotates. It's getting old. (Problems to be Solved by the Invention) However, in the conventional speed change pulley that uses centrifugal force as described above, the portion between the guide portions becomes a gap, making it impossible to obtain a large thrust, and therefore the V-belt In order to extract the centrifugal force necessary to transmit power in combination with the It was necessary to increase the turning radius. For this reason, the above-mentioned conventional transmission has the disadvantage that it is difficult to put it into practical use in a low rotation range, and the transmission pulley itself requires a large space. Therefore, the present invention addresses the above-mentioned facts and
The challenge is to eliminate these difficulties, and among others,
By eliminating the guide such as the conventional steel ball guide and enlarging the gap and filling it with a large number of small metal balls, etc., the movement of the balls in the space is made more active than in the past, thereby reducing the effect of centrifugal force. The purpose is to improve efficiency. (Means for Solving the Problems) Therefore, the characteristics of the pulley of the present invention that is suitable for the above purpose will be explained based on the embodiment shown in FIG. A movable V pulley piece 2 is disposed so as to be slidable in the axial direction facing the V pulley piece 1, and an extending portion 2a extending rearward is formed on the outer edge of the movable V pulley piece 2.
A movable V is inscribed in the inner surface of the extension part 2a of the pulley piece 2 on the extension of the axis on the back side of the pulley piece 2.
A sliding support 3 for the pulley piece 2 is provided integrally with the shaft. In this case, the sliding support 3
and the extending portion 2a of the V-pulley piece 2 as a sliding portion, and between the back side of the sliding support 3 and the spring receiver 4 provided on the inner surface of the extending portion 2a of the movable V-pulley piece. V between fixed V pulley piece 1 and movable V pulley piece 2
The return spring 1 has a thrust force in the direction in which the groove width widens.
A centrifugal force imparting material 9 consisting of a large number of small metal balls is placed in a space surrounded by the axial extension of the fixed V-pulley piece 1, the back surface of the movable V-pulley piece 2, and the inner surface of the sliding support 3. The applying material 9 is disposed so as to be freely movable within the space, thereby generating pressure on the back side of the movable V-pulley piece 2 by the centrifugal force during rotation of the pulley. Fixed V
A thrust force can be generated in the direction toward the pulley piece 1, and the thrust force can be automatically adjusted according to the number of rotations of the pulley. It is important that the centrifugal force imparting material 9 be able to move automatically within the space as described above, and such a centrifugal force imparting material is also effective in reducing space loss. be. (Function) The speed change pulley configured as described above has a low rotational speed and when the groove width between the fixed V pulley piece 1 and the movable V pulley piece 2 is maximum, the centrifugal force imparting material in the space is is substantially satisfied, and the centrifugal thrust caused by the rotation and the return thrust caused by the return spring 10 are kept in balance. Then, when the rotational speed increases and the thrust due to centrifugal force increases against the thrust of the return spring 10, the movable V-pulley piece 2 moves toward the fixed V-pulley piece 1, and the effective diameter of the belt 5 increases. At this time, as mentioned above, the loss in the space is reduced, a larger thrust is obtained than in the conventional system, and it becomes possible to use the system at a low rotation speed or with a smaller pulley diameter. (Embodiments) Hereinafter, embodiments of the present invention will be described further based on the accompanying drawings. Figures 1A and 1B show a first embodiment of the present invention, in which a movable V-pulley piece 2 is provided facing the extension of the axis A of the fixed V-pulley piece 1, and the extended axis A sliding support 3 of a movable V-pulley piece is rotated integrally in the rotation direction by a key or spline 7, and a stop spring 1 is rotated in the thrust direction.
2 and 13. An extending portion 2a extending rearward is formed on the outer edge of the movable V-pulley piece 2, and the outer circumferential surface of the sliding support 3 is disposed within the inner circumferential surface of the extending portion 2a. The movable V-pulley piece 2 and the sliding support body 3 are configured to move freely in the thrust direction and rotate together in the rotating direction by a sliding key 6. Further, a spring receiver 4 is provided on the inner circumferential surface of the extending portion 2a of the movable V pulley piece 2, which is integrated with a key 8 in the rotational direction and fixed by a stop ring 11 in the thrust direction.
A return spring 10 is interposed between the back side of the sliding support body 3 and the opposing sliding support body 3. This return spring 10 is arranged so as to generate a thrust in a direction that always opens the V groove width between the fixed V pulley piece 1 and the movable V pulley piece 2. Therefore, in the illustrated example, in the above structure, a ball bearing is installed in a space surrounded by the extension of the axis A of the fixed V-pulley piece 1, the back surface of the movable V-pulley piece 2, and the inner surface of the sliding support 3. A large number of small steel balls 14, such as the steel balls of ). Usually, it is preferable that the small steel balls 4 occupy approximately 80% of the volume of the space when the groove width of the fixed V-pulley piece 1 and the movable V-pulley piece 2 is at its maximum.
It is loaded with this guideline in mind. But of course,
This amount is appropriately determined depending on the required centrifugal force. FIG. 1A shows the case where the groove width of the fixed V-pulley piece 1 and the movable V-pulley piece 2 is at its maximum, and the centrifugal thrust due to rotation and the return thrust due to the return spring 10 are in a balanced state. In addition, B is a case where the rotation speed is increased and the thrust due to the centrifugal force increases against the thrust of the return spring 10, and the movable V-pulley piece 2 moves by the required distance x toward the fixed V-pulley piece 1. . The amount of the moving distance x of the movable V-pulley piece 2 depends on the tension on the tight and loose sides of the V-belt that occurs during power transmission, the V-angle, the friction coefficient of the belt, the thrust of the other speed change pulley, etc., and the pulley of the present invention. It is determined by the rotation speed of the return spring 10, the thrust of the return spring 10, the shape and width of the ball insertion space, etc. Now, regarding the embodiment shown in FIG.
In the figure, the moving distance x of the movable V pulley piece 2 is x = {2 [(D ₁ ³ − D ₂ ³ )/3 − D ₂ ² (D ₁ − D ₂ )]−2/3
(D ₁ ³ −y ³ )+2y ² (D ₁ −y)}/(D ₁ ² −y ² )tanθ/2

...() Centrifugal thrust FX is Fx=7.8Kπ ³・N ² (D ₁ ² −y ² ) ² /36/9.8/10″
...() becomes. However, in the formula, D ₁ is the upper limit radius of the centrifugal force imparting material (ball) during rotation when the groove width is maximum, D ₂ is the lower limit radius at that time, and y is the centrifugal force imparting material (ball) when the groove width is minimum. (ball) lower limit radius, θ is the apex angle of the space, N is the pulley rotation speed (rpm), and K is the space filling ratio (usually 0.58) occurring between the balls. Also, the specific gravity of the ball is 7.8. Next, the pitch radius (Rx) of the belt is Rx = Ro + x / 2tanΦ / 2 ... () However, Ro is the minimum pitch radius of the belt, and Φ is the belt V angle. From the above formula, when the rotation speed N is fixed, The centrifugal thrust (Fx) changes depending on the value of (D ₁ ² −y ² ).
Also, the relationship between D ₁ and y is expressed as D ₁ D ₂ in equation ().
When fixed, the relationship between the moving distance x and y of the movable V-pulley piece 2 changes depending on the size of the spatial apex angle θ. As for the value of , when θ is increased, y becomes smaller, and conversely, when θ is smaller, y becomes larger. Therefore, D ₁ , D ₂ , the minimum pitch radius of the belt Ro
Also, by fixing the belt V angle Φ, load H ((Ps), and rotation speed N (rpm) and varying only θ, calculate the moving distance x of the movable V pulley piece, centrifugal thrust Fx, and belt pitch radius Rx. The results are as shown in Tables 1 and 2 and Figure 6 below.

【table】

【table】

[Table] Comparing each thrust force Fx in the above table with that of the conventional centrifugal thrust type with one steel ball, the former is the same as that of the present invention for the same pulley diameter, the same rotation speed, and the same travel distance of the movable V-pulley piece. Only about 1/5 of the thrust is produced,
In this respect, the present invention has the advantage that it is possible to obtain a thrust force that is 2 to 5 times larger, and that it is easy to adjust the thrust force between them. In addition, in the embodiment shown in FIG. 1, the centrifugal force imparting material is a small steel ball (ball), but in this case,
In order to improve the sliding between each ball inside the space,
It is desirable to include a lubricant. In addition, since the balls directly contact the back side of the movable V-pulley piece 2 and the inner surface of the extension portion 2a and the inner surface of the sliding support 3, it is possible to provide the sliding portion with wear resistance. desirable. Further, the hardness of the ball may be lower than that of a normal bearing, or the ball may be hardened to a slightly higher hardness than a normal ball by quenching. By the way, the centrifugal force imparting material made of metal globules of the liver and kidney of the present invention may be spherules made of metal powder solidified with resin, in addition to spherules made of copper, iron, stainless steel, etc. You may use a mixture of different ones. It is essential that these be able to move freely in space, thereby producing a thrust effect similar to that of liquid. In addition, although the space for accommodating the centrifugal force imparting material has a triangular cross section in FIG. It is also preferable to have the shape of FIGS. 2, 3, and 4 all show variations of the space shape, and in FIG. 2, the back side of the movable V-pulley piece 2 and the inner surface of the sliding support 3 are both rounded The third example is an arc shape with
In the figure, the inner surface of the sliding support 3 is a surface perpendicular to the axis, and the back side of the movable V pulley piece 2 is involute-shaped.
An example is shown in which both the back side of the pulley piece 2 and the inner surface of the sliding support body 3 are formed into a stepped shape so that the outer circumference is narrow and the area closer to the axis is wider. Of course, other shapes than those described above are also possible. In addition, in the embodiments shown in FIGS. 1 to 4,
Both ends of the return spring 10 have no locking parts and are interposed in an oven state, but this design can also be changed, and in FIG. Locked by 15,
A so-called spring lock method is adopted. In this case, the movable V-pulley piece 2 twists and rotates in the axial direction at the x point due to the return force of the spring, and moves from side to side, but the thrust force is the same as in the case described above. Thus, the present invention is implemented according to the embodiments described above, and a large thrust is obtained to facilitate practical application in a low rotation range. (Effects of the Invention) As described above, the present invention provides a variable speed pulley that utilizes centrifugal force, in which a sliding support is attached to the movable V-pulley piece to support it, and a large number of sliding supports are attached to the movable V-pulley piece, and a large number of sliding supports are provided in the space formed by the shaft and both. Compared to conventional methods, it is loaded with a centrifugal force imparting material made of small metal balls.
There is little loss of void space, so the same pulley diameter,
A larger thrust can be obtained at the same rotation speed and the same travel distance of the movable V-pulley piece.
It has the advantage of being able to be used with a small pulley diameter, and is expected to have a significant effect as a centrifugal thrust type variable speed pulley, greatly improving conventional variable speed pulleys.

[Brief explanation of the drawing]

Figures 1A and 1B are side sectional views of essential parts of an example of the speed change pulley of the present invention, where A is the case where the V groove width is maximum, and B is the V groove width.
The case with the minimum groove width is shown. Figures 2 to 4 are side sectional views of essential parts showing various modified embodiments of the speed change pulley of the present invention, and Figure 5 is also a modified embodiment, with the upper half showing the minimum V-groove width and the lower half showing the modified embodiment. The section shows the maximum V-groove width. FIG. 6 is a chart showing the relationship between the moving distance of the movable V-pulley piece and the thrust force. 1... Fixed V pulley piece, 2... Movable V pulley piece, 3... Sliding support, 4... Spring receiver, 5
... V-belt, 9 ... centrifugal force imparting material, 10 ... return spring, A ... shaft.

Claims (1)

[Claims] 1. A movable V-pulley piece is disposed on the axial extension of the fixed V-pulley piece so as to be able to slide in the axial direction opposite to the fixed V-pulley piece, and a rearward extending portion is formed on the outer edge of the movable V-pulley piece. At the same time, on the back side of the movable V pulley piece, a sliding support body is provided integrally with the shaft so as to be inscribed on the inner surface of the extension part of the movable V pulley piece on the extension of the shaft, and the sliding support body and the movable V pulley piece A sliding part is formed between the fixed V pulley piece and the movable V pulley piece, and a sliding part is formed between the fixed V pulley piece and the movable V pulley piece. V between
A return spring is interposed so as to have a thrust in the direction in which the groove width widens, and a return spring is provided in the space surrounded by the axial extension of the fixed V-pulley piece, the back surface of the movable V-pulley piece, and the inner surface of the sliding support. A centrifugal force imparting material consisting of a large number of small metal balls is housed so that it can move freely inside.
The centrifugal force exerted by the centrifugal force imparting material during the pulley rotation generates pressure on one back side of the movable V-pulley to generate a thrust force in one direction of the fixed V-pulley, and the thrust force is automatically adjusted according to the rotation speed of the pulley. A centrifugal thrust variable speed pulley that is characterized by its ability to move freely.