JPH02300520A - Torque limiter - Google Patents

Abstract

PURPOSE:To obtain a stable torque and to facilitate the setting of a torque while making a starting torque satisfactory by providing friction means and bearing plates which are alternately arranged on both sides of a flange section, and a pair of springs disposed between each adjacent friction means. CONSTITUTION:When a first member 10 is rotated, second plates 32, 32' on the second member 20 side make contact with both surfaces of a flange section 12, and first plates 31, 31' on the first member 10 side make contact with the outer surface thereof while third plates 33, 33' make contact with the outside thereof. Further, press contact forces are given by springs 34, 34' in the contact parts, and accordingly, the rotation of the first member 10 may be transmitted to the second member 20 under a torque corresponding to friction forces on several contact surfaces. At this time, since the first member 10 having the flange section 12 receives, on its both sides, pressing forces by the pressing springs 34, 34', the springs 34, 34' are balanced with equal pressures so as to absorb the forces, thereby it is possible to set the setting value of the torque to be constant.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention transmits torque from one member to another, and when the load exceeds a set value, slip occurs and torque transmission is canceled. This relates to torque limiters.

(Prior art) There are devices for controlling torque transmission that manage friction.
The inventions described in No. 524 and No. 51-22135 are publicly known.

The above-mentioned torque control device uses friction (in some cases, shallow uneven engagement) between the input end member and the output side member.

) to manage the transmittable torque by causing slippage at a set value.

(Technical issues) However, with torque management using friction, it is difficult to change or adjust the torque once it has been set, and it is difficult to maintain a constant set value due to variations in the machining accuracy of the friction surface and variations in frictional resistance. In particular, precise torque management is difficult. To solve this problem, a torque limiter in which the frictional force is set by the pressing force of a spring has been developed, and some applications have already been filed. The present invention was made as a result of this development, and its purpose is to provide a torque limiter that can provide stable torque, is easy to set torque, and has very good starting torque.

(Technical Means) The object is to provide a first member having a hollow shaft shape that is rotatable around an axis and has a flange-like part projecting radially outward in the middle part; a second member having an inner diameter capable of accommodating the brim; a pair of bearing plates provided on the second member for pivotally supporting the first member on the second member; a pair of friction means each engaged with the second member and consisting of a plurality of plates arranged alternately on both sides of the brim portion; and a pair of springs interposed in a compressed state between the bearing plate and the friction means. This can be achieved by a configuration that includes the following.

(Example) A description will be given below with reference to the drawings. In each figure, 10 is the first
The member 20 is a second member, and both members are combined so as to be rotatable around the l axis. The illustrated first member 10 has a hollow tubular shaft portion 11, and a circular flange-like collar portion 12 protruding radially outward is integrally provided at the intermediate portion thereof.

The second member 20 has a cylindrical shape with an inner diameter capable of accommodating the brim portion 12, and is provided with a pair of bearing plates 21 and 22 at both ends, with one bearing plate 21 being integrally formed. , the other bearing plate 22 can be adjusted in position on the shaft by means of threads 23.24. Reference numerals 25 and 26 indicate bearing holes for bearing the shaft portion 11.

Friction means 30, 30' are provided on both sides of the collar 12,
A first plate 31.31' is provided with a projection 14 in the shaft hole 15 that engages with a guide groove 13.13' formed in the shaft portion 11 so as to be movable in the axial direction of the first member 10; a second plate 32.32' having a protrusion 17 protruding from its outer periphery that engages with a guide groove 16 formed on the inner surface so as to be movable in the axial direction of the member 20;
The third one has the same structure as the one and has a spring receiving groove 18 on the outer surface.
a third plate 33;
．． 33' and the bearing plates 21, 22 under the elastic force of the springs 34, 34' interposed in a compressed state, the flanges 12 on the first member side, the plate 31, and the plate 3 on the second member side
2.33 are arranged alternately.

A plurality of plates 12 constituting friction means 30, 30'
．． 31 to 33, concentric annular irregularities 35 and 36 are formed on the frictional surfaces of the brim 12 on the first member side and the first plate 31, and the plate 3 on the second member side contacts with the concentric annular irregularities -35 and 36.
2.33 has a line contact part 37.38.3 extending in the radial direction.
9 are provided to protrude radially. Since the arrangement of each plate, the annular unevenness, and the line contact portion described above are symmetrical with respect to the brim portion 12, the same parts are indicated by adding a dash to the reference numerals.

The length of the pair of pressure springs 34, 34' can be changed by moving the bearing plate 22 in the axial direction, thereby changing the spring acting force and adjusting the pressing force of the entire friction means.

In each figure, 40 is a rotating shaft inserted into the first member 10, and 41
42 is a keyway provided in the shaft portion 11 for engagement with the pin 41. In the above configuration, only an example in which the brim portion 12 is provided on the first member 10 has been described, but it is also possible to provide the brim portion 12 on the second member 20, and in that case as well, it is possible to provide the brim portion 12 on the second member 20. (Similar effects can be obtained. Other changes such as simplification or expansion of the structure are free.

(Function) If the first member 10 is now rotated, the second plates 32, 32' on the second member 20 side will come into contact with both surfaces of the brim portion 12, and the Plate 31.
31', and a third plate 33.33' on the second member side is in contact with the outer side thereof, and each contact portion is connected to a spring 34.3.
4', and the rotation of the first member 10 is applied to the second member 2 with a torque corresponding to the frictional force of a large number of contact surfaces.
0 can be transmitted.

At this time, since the first member 10 having the flange-like portion 12 receives pressure from the pressure springs 34, 34' from both sides, the springs 34, 34' are balanced with the same pressure, and the line contact surface is pressed with high precision. Even if there is variation, this is absorbed and the torque setting value remains constant. In addition, torque adjustment is done using bearing plate 2.
This is done in two steps. Torque transmission is through line contact part 37.3
8.39.37', 38', and 39', the variation in frictional force is extremely small. In a structure that obtains friction force through surface contact, even if the surface flatness and surface roughness are precisely finished, the torque generated by static friction and dynamic friction will vary, causing fluctuations in the starting torque. According to the configuration of the invention, the annular irregularities 35, 36, 35', 36'
Coupled with the improvement in flatness, the torque value to be managed becomes extremely accurate.

(Effects) Since the present invention is constructed and operates as described above, it exhibits the following effects.

■The fluctuation range of the set torque can be made very small.

- Since the friction means consists of a plurality of plates, the torque fluctuation range is small regardless of whether the rotation speed is low or high, and the starting torque characteristics are also very good when slip occurs from the torque transmission state.

■Friction value is set by stress concentration due to line contact, and stress relaxation is achieved by friction means consisting of multiple plates, so a large frictional force can be obtained with a small compressive load.

■The required torque can be obtained by increasing or decreasing multiple plates.

■Radial and concentric contact suppresses torque variations caused by simple line contact.

[Brief explanation of drawings]

The drawings show an embodiment of the torque limiter of the present invention, and FIG. 1 is an exploded perspective view, FIG. 2 is a vertical sectional view, and FIG. 3 is a second
It is a sectional view taken along the line A-A. lO...first member, 12...flange-shaped part, 20...second member, 21.22...bearing plate, 30.30'...
Friction means, 31.31'...first plate, 32.3
2'...Second plate, 33.33'...Third plate, 34.34'...Spring.

Claims (3)

[Claims] (1) A first member that is rotatable around an axis, has a hollow shaft shape, and has a flange-shaped part protruding radially outward in the middle part, and a first member that is rotatable about the same axis and accommodates the flange-shaped part. a pair of bearing plates provided on the second member for pivotally supporting the first member on the second member; and a pair of bearing plates movable in the axial direction and respectively engaged with the first member and the second member. A torque limiter comprising a friction means consisting of a plurality of plates arranged alternately on both sides of a flange-like part, and a pair of springs interposed in a compressed state between the bearing plate and the friction means. . (2) The torque limiter according to claim 1, wherein the friction means comprises a first plate engaged with the first member and a second plate engaged with the second member. (3) The torque limiter according to claim 2, wherein the first plate and the second plate are configured to contact each other at a line contact portion extending in the radial direction.