JPH0537064Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an automatic balancing device for a rotating body.

(b) Prior art A conventional method for correcting the unbalance of a rotating body is to attach correction weights to the rotating body by welding, plastic deformation, etc., as shown in, for example, Japanese Utility Model Application Publication No. 70302/1983. There is a way. In other words, rotate the rotating body using a balance tester,
The magnitude and direction of the unbalance are detected, and a weight of a predetermined weight is attached to a predetermined location accordingly.

(c) Problems that the invention aims to solve However, in addition to the problem that correcting the unbalance of a rotating body as described above requires a large number of man-hours,
Even if the unbalance of a rotating body such as a road wheel is corrected as described above, this is only to prevent unbalance from occurring when the rotating body is installed in the tester. If it is installed in a tester, there is a problem in that the mounting relationship is different from that of the tester, which may cause imbalance. Furthermore, in the case of a rotating body that changes over time, such as a vehicle tire, the unbalance may gradually increase even if the balance is corrected once. It can also occur due to wear, deformation of the connecting part, etc.

Incidentally, as a solution to the above-mentioned problems, there is a method disclosed in Japanese Patent Application Laid-open No. 73673/1983. That is, three 1/3 arc-shaped ring ballasts are provided inside a ring-shaped container, a plurality of balls are arranged between the inner peripheral surface of the ring container and the ring ballast, and the ring ballast is A force is applied in the center direction using a spring. As a result, when the rotation speed is high, the ring ballast moves toward the outer circumference due to centrifugal force, allowing the ball to move and automatically correcting the balance, while when the rotation speed decreases, the ball is restrained by the spring. A balanced state is maintained. However, in the case of what is shown here, what is the specific structure of the ring-shaped container, and how is the ring ballast,
It is unclear whether balls, springs, etc. will be incorporated inside, and therefore it is also unclear how each part will be maintained and inspected. Further, the inner circumferential surface of the ring ballast along which the outer circumferential side of the ball is guided is a flat surface when viewed in radial cross section, and makes point contact with the ball. Therefore, there is a problem that the ball does not necessarily move smoothly during high speed rotation.

The present invention aims to solve these problems.

(d) Means for solving the problem The present invention is such that the ball, the pressing member, and the spring are held by a casing and a cover attached to the casing, and the annular raceway surface with which the ball comes into contact has an arcuate cross section. By doing so, the above problem is solved. In other words, the rotating body automatic balance device according to the present invention includes a casing 18 that is provided to rotate integrally with the rotating bodies 10 and 12 around the rotation axis thereof, and a casing 18 that is provided on the casing 18 concentrically with the rotation axis. an annular raceway surface 22; two or more balls 34 movably guided along the annular raceway surface 22; Pressing member 30 divided into arc shapes
and a spring 32 that applies a force in the direction of the center of rotation to the pressing member 30, so that the ball 34 moves along the annular raceway surface 22 when the rotational speed of the rotating bodies 10, 12 exceeds the set rotational speed. ball 34
is released from the pressing member 30, and the rotating bodies 10, 12
When the rotational speed of
In the automatic rotating body balance device configured to be restrained against the ball 30 , the ball 34 is held within the annular raceway surface 22 by a cover 26 attached to the side surface of the casing 18 with screws 24 , and the pressing member 30 and the spring 32 is configured to be held on the outer periphery of the ball 34, and the annular raceway surface 22 of the casing 18 is formed in an arc shape having a radius larger than the radius of the ball 34 in the radial cross section. It is a feature.

(E) Effect When the rotating body rotates at a rotational speed higher than the set speed, two or more balls provided on the annular raceway become unrestrained and can move freely along the annular raceway. Become. This causes two or more balls to automatically move to balanced positions. If the rotational speed of the rotating body decreases in this state,
The ball is restrained against the annular raceway surface by the pressing member. Therefore, the ball is fixed to the annular raceway surface in a balanced state. In this way, the balance is automatically corrected every time the rotational speed of the rotating body exceeds the set rotational speed, so there is no need for initial balance correction work, and any unbalance that occurs over time is automatically corrected. will be done. When the screws are loosened and the cover is removed, the ball, pressing member, and spring can be taken out, making maintenance and inspection of the parts easy. Further, since the ball moves along the annular raceway surface of the casing having an arcuate cross section, the ball moves smoothly during high speed rotation.

(F) Embodiment Figures 1 and 2 show embodiments of the present invention. In this embodiment, the rotating body whose balance is to be corrected is a propeller shaft of an automobile. An automatic balance device 14 is provided between the flange 10 at the rear end of the propeller shaft and the flange 12 of the final drive device.
and 12 and a casing 18 connected by bolts 16 so as to rotate together. The approximately disk-shaped casing 18 has flanges 10 and 12
placed concentrically with. The casing 18 has an annular groove 20, and a wall surface on the outer peripheral side of the groove 20 forms an annular raceway surface 22 centered on the rotation axis. The annular raceway surface 22 has a cross section with a predetermined radius of curvature (that is, a radius slightly larger than the radius of a ball 34, which will be described later). A cover 26 is attached to the casing 18 with screws 24 so as to cover the groove 20. The cover 26 has an annular groove 28 in which a pressure member 30 and a spring 32 are provided. The pressing members 30 are quarter-arc shaped members, and four pressing members 30 are arranged around the entire circumference of the groove 28. The pressing members 30 are each pressed toward the center of the rotating shaft by two springs 32. Further, as shown in FIG. 1, the inner peripheral side cross section of the pressing member 30 is
The shape is such that it constitutes a continuous surface with the annular raceway surface 22 of. Two steel balls 34 are inserted into the groove 20.

Next, the operation of this embodiment will be explained. When the automatic balancing device 14 is at rest and rotating at a low rotational speed, the balls 34 are pressed radially inwardly by the springs 32 via the pressing member 30 and against the casing 18. is in a restrained state.

When the automatic balance device 14 starts to rotate at a higher speed than the predetermined set rotation speed from this state, the centrifugal force acting on the pressing member 30 increases, and the pressing member 30 compresses the spring 32 and rotates outward in the radial direction. The player then moves away from the ball 34. Therefore, the ball 34 is released from the restraint state and becomes freely movable along the annular raceway surface 22 having an arcuate cross section. At sufficiently high rotational speeds, the two balls 34 will automatically move to a balanced position. This principle itself is shown, for example, in "Mechanical Vibration Theory" (written by Den Hartske), page 261. Therefore, even if there is an imbalance before the set rotational speed is reached, the balance is automatically corrected when the set rotational speed is exceeded. When the rotation speed decreases from this state and becomes smaller than the set rotation speed, the pressing member 3
The centrifugal force acting on the ball 34 is reduced, and the ball 34 is again restrained by the spring 32 and the pressing member 30. The ball 34 is in a balanced position until just before it is restrained by the pressing member 30, and since it is restrained in that position, the balanced state is maintained even if the rotational speed decreases. That will happen.

After all, each time the rotational speed of the flanges 10 and 12, which are rotating bodies, exceeds the set rotational speed, the balance is corrected by the automatic balance device 14, and this state is maintained even after the rotational speed decreases. Therefore, there is no need for balance correction work, and since the balance is constantly corrected, unbalances that occur over time can also be corrected, and the flanges 10 and 12 are always rotated in a balanced state. be able to.

(g) Effects of the invention As explained above, according to the invention, the ball, pressing member, and spring are held by the cover attached to the side of the casing, making maintenance and inspection of these parts easy. Also, since the radial cross section of the annular raceway surface is arc-shaped, the ball can move smoothly during high-speed rotation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an automatic rotating body balancing device according to an embodiment of the present invention, and FIG. 2 is a front view of the automatic rotating body balancing device shown in FIG. 1. 10, 12...flange (rotating body), 22...
Annular raceway surface, 30...pressing member, 32...spring, 34...ball.

Claims (1)

[Claims for Utility Model Registration] A casing 18 that is provided to rotate integrally with the rotating bodies 10 and 12 about their rotational axes.
, an annular raceway surface 22 provided on the casing 18 concentrically with the rotation axis, two or more balls 34 movably guided along the annular raceway surface 22, and an annular raceway surface 22 provided on the balls 34. a pressing member 30 that is arranged so as to touch from the outer peripheral side and is divided into a plurality of arc shapes; a spring 32 that applies a force in the direction of the rotation center on the pressing member 30;
When the rotational speed of the rotating bodies 10, 12 exceeds the set rotational speed, the ball 34 is released from the pressing member 30 so that the ball 34 moves along the annular raceway surface 22, and the rotational speed of the rotating bodies 10, 12 decreases. In an automatic rotating body balance device configured such that the ball 34 is restrained against the annular raceway surface 22 by the pressing member 30 when the rotational speed is smaller than the set rotational speed, The ball 34 is held within the annular raceway surface 22 by the cover 26 attached to the casing 18, and the pressing member 30 and the spring 32 are held on the outer periphery of the ball 34. An automatic rotating body balance device characterized in that it is formed in an arc shape having a radius larger than the radius of the ball 34 in a directional cross section.