JP2553112B2 - Torque limiter - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a torque limiter used in a torque transmission mechanism.

[Prior art and its problems]

Conventionally, a torque limiter of this kind has a rotation transmitting member rotatable with respect to a shaft, a friction member and a pressing plate that presses the friction member from both sides and rotates integrally with the shaft, and a pressing spring that applies pressure to the pressing plate. There is known a torque limiter which is composed of the following and limits the transmission torque by the frictional force between the side surface of the rotation transmission member and the friction member (for example, Japanese Patent Laid-Open No. 62-62).
224727). However, the conventional torque limiter described above has a problem in that the frictional force between the disc-shaped rotation transmitting member and the frictional member varies, and the torque limiting accuracy is unstable due to the variation.

[Means for solving problems]

In order to solve the above-mentioned problems, the torque limiter of the present invention has an outer member having one of a cylindrical surface and an inclined cam surface formed on the inner circumference, and an inner member having the other formed on the outer circumference, The cylindrical surface and the inclined cam surface are opposed to each other, a plurality of rolling elements arranged between them, a cage provided with a pocket for accommodating the rolling elements one by one, and the rolling element inclined with respect to the cylindrical surface. A spring which presses a wedge surface formed by the cam surface and a gap in the direction of rotation between the rolling element and the pocket, and the inclined cam surface of the inner member and the outer member. A torque setting elastic member is provided between the member on the holding side and the retainer, and when a torque equal to or greater than the set torque is applied, the retainer is attached to the member on the side having the inclined cam surface until the clearance in the rotation direction disappears. Relative rotation to the rolling element Those constructed as to disengage with Jo surface. As a result, the transmission torque is accurately sensed by the elastic deformation of the torque setting elastic member, and when the torque exceeds the torque limit value, the clutch composed of the rolling element and the wedge-shaped surface is released and the torque is cut off. High accuracy of restriction.

【Example】

1 and 2 show a torque limiter according to a first embodiment of the present invention, and FIG. 1 is a sectional view taken along line XX of FIG. This embodiment is applied to a separation roller used in a paper feeding section of a copying machine or the like. The torque limiter 1, the outer member 2, the inner member 3, the rolling elements 4, the cage 5, and the spring 6 are the main components, and the outer member 2 has a cylindrical surface 7 formed on the inner periphery thereof. The outer circumference of the inner member 3 is cylindrical, and inclined cam surfaces 8 are formed at three positions at equal intervals. The retainer 5 has a pocket 9 for accommodating the rolling element 4.
Is formed corresponding to the inclined cam surface 8, and the spring 6 is incorporated in the recess 10 provided in the pocket wall portion. The spring 6 presses the rolling element 4 against the wedge-shaped surfaces 20, 20 'formed by the cylindrical surface 7 and the inclined cam surface 8. A rolling direction clearance A is provided between the rolling element 4 and the wall surface 11 of the pocket. A torque setting elastic member 12 is provided between the inner member 3 and the cage 5, and
A stopper 13 is formed on the inner circumference of the stopper 13 to prevent unnecessary relative rotation with the inner member 3. Outer member
2, the cage 5 and the inner member 3 are slidably fitted to the respective members so as to be rotatable relative to each other. The boss portion 14 of the retainer 5 is fitted to the input shaft 15 and the set bolt 16
It is fixed at 15. On the other hand, the outer member 2 is integrally connected to the separating roller 17. 18 is a positioning plate and 19 is a retaining ring. Next, the operation of this torque limiter will be described. The input shaft is rotating in the direction of arrow B shown in FIG. Separation roller
When the load torque of 17 is less than or equal to the set torque, the torque setting elastic member is less flexed, and the rolling elements 4 and the wall surface of the pocket
There is a gap in the direction of rotation between 11 and. The rotational force of the input shaft 15 causes the inner member 3 to rotate rightward from the cage 5 via the torque setting elastic member 12. At this time, the inclined cam surface 8
The rolling element 4 is pressed by the spring 6 against the wedge-shaped surfaces 20 and 20 'formed by the cylindrical surface 7 and the cylindrical surface 7, and the clutch is actuated to transmit the rotational force to the outer member 2 to be integrated with the outer member 2. The combined separation roller 17 rotates to the right. Next, when a torque equal to or larger than the set torque is applied to the separation roller 17, the torque setting elastic member 12 bends and the direction of rotation between the rolling element 4 and the wall surface 11 of the pocket is changed as shown in FIG. The cage 2 rotates to the right relative to the inner member 3 until the clearance disappears, the pocket wall surface 11 presses the rolling element 4 to disengage it from the wedge-shaped surfaces 20, 20 ', and the separation roller 17 moves. Rotates to the left due to the load torque. Thereby, the torque setting elastic member 12 accurately sets the limiting torque. 4 and 5 show a second embodiment of the present invention. In this embodiment, the cylindrical surface and the inclined cam surface are arranged opposite to the torque limiter of the first embodiment. That is,
An inclined cam surface 38 is formed on the inner circumference of the outer member 32. The inner member 33 is integrally formed with the shaft 45, and a cylindrical surface is formed on the outer periphery of the shaft 45.
37 are formed. The cage 35 is integrally coupled to the separation roller 47, and is rotatable relative to the input shaft 45. A torque setting elastic member 42 is provided between the retainer 35 and the outer member 32, one end of which is attached to the outer member 32 and the other end of which is attached to the retainer 35. The torque setting elastic member 42 is a torsion coil spring. Rolling element
A rotation direction clearance A is provided between 34 and the wall surface 41 of the pocket of the retainer 35 as in the first embodiment, and the rolling element 34 uses the spring 36 to allow the inclined cam surface 38 and the cylindrical surface. It is pressed against the wedge-shaped surfaces 50, 50 'formed by 37 and. The rotational force of the input shaft 45 is transmitted to the outer member 32 via the rolling elements 34, and further via the torque setting elastic member 42, the cage 35,
It is transmitted to the separation roller 47. Incidentally, 51 is a retaining ring that prevents the outer member 32 and the retainer 35 from separating. In the present embodiment, the retainer 35 is a separation roller 47 whose output side is
The spring 36 and wedge-shaped surfaces 50, 50 'are oriented in the opposite direction to that of the first embodiment. The operation is the same as that of the first embodiment, so the description is omitted. FIGS. 6 and 7 show a third embodiment, which is applied between two shafts for transmitting a rotational force, and the structure is almost the same as that of the second embodiment. . The boss portion 74 of the cage 65 is fitted to the output shaft 77, and is fixed in the rotational direction by the key 82. 76 is a holding bolt for the key 82. The torque setting elastic member 72 is a torsion coil spring, and both ends thereof are engaged with the slits 83 and 84 provided in the outer member 62 and the cage 65, respectively. Other configurations are the same as those in the second embodiment.

【effect】

Since the present invention is configured as described above, it has the following effects. (I). The torque setting elastic member senses the transmitted torque by bending, and when the torque exceeds a torque limit value, the torque limiter has a high accuracy because it is a torque limiter having a structure for releasing the clutch including the rolling elements and the wedge-shaped surface. (B). Since the components are in the shape of a relatively simple ring, they can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view of a torque limiter according to a first embodiment of the present invention, FIG. 2 is a vertical sectional view showing a first embodiment of the present invention, and FIG. 3 is a first embodiment of the present invention. Illustration of operation of example, 4th
FIG. 5 is a lateral sectional view of a torque limiter according to a second embodiment of the present invention, FIG. 5 is a side view of a partial vertical section of the second embodiment, and FIG. 6 is a torque according to a third embodiment of the present invention. FIG. 7 is a horizontal sectional view of the limiter, and FIG. 7 is a vertical sectional view of the third embodiment. 1,31,61 …… Torque limiter 2,32,62 …… Outer member 3,33,63 …… Inner member 4,34,64 …… Rolling element 6,36,66 …… Bane 7,37 , 67 …… Cylindrical surface 8,38,68 …… Inclined cam surface 12,42,72 …… Torque setting elastic member 20,20 ′, 50,50 ′, 80,80 ′ …… Wedge surface

Claims (1)

(57) [Claims] 1. An outer member having one of a cylindrical surface and an inclined cam surface formed on the inner circumference, an inner member having the other formed on the outer circumference, and the cylindrical surface and the inclined cam surface opposed to each other. , A plurality of rolling elements arranged between them, a cage having pockets for accommodating the rolling elements one by one, and the rolling elements facing a wedge-shaped surface formed by the cylindrical surface and the inclined cam surface. Between the rolling member and the pocket, which is provided with a pressing spring, and which has a rotational gap between the rolling member and the pocket, and between the inner member and the outer member having the inclined cam surface and the retainer. A torque setting elastic member is provided to the cage, and when a torque equal to or greater than the set torque is applied, the cage rotates relative to the member having the inclined cam surface until the rotation direction clearance is eliminated, and the rolling element and the wedge-shaped surface are formed. It is characterized in that the engagement of Torque limiter.