JPH04131527A - Torque limiter - Google Patents

Abstract

PURPOSE:To reduce assembling space considerably by installing rolling members between a first cam surface and the outer circumferential surface of a second outer ring, and between a second cam surface and the shaft surface respectively, and pressing the rolling members with elastic members in the direction of wedging in the gaps either between the first cam surface and the second outer ring, or between the second cam surface and the shaft. CONSTITUTION:Cages 9 and 10 are respectively installed between a first outer ring 4 and a second outer ring 5, and between the second outer ring 5 and a shaft 1. Rollers 11 and rollers 12 are installed in pockets 9a and pockets 9b respectively of the cages 9 and 10. Elastic members 15 and 16 are provided respectively between holding surfaces 13, 14 formed on the first outer ring 4 and the second outer ring 5 and rollers 11, 12 so as to press respective rollers in the direction of wedging the rollers 11, 12 respectively in between the first cam surface 7 and the second outer ring 5, or between the second cam surface 8 and the shaft 1. By adjusting the wedge angle of the first cam surface 7 and the spring force of the elastic member 15, on and off torque can be set relative to the rotation of the second outer ring 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a torque limiter that can transmit different torques for rotation in both directions.

[Prior Art] Conventionally, there is a torque limiter that utilizes the basic structure of a one-way clutch, which was proposed by the present applicant in U.S. Pat. No. 63-55348.

As shown in FIGS. 5 and 6, this torque limiter consists of an outer ring 41 having a plurality of clutch cam surfaces 42 on its inner peripheral surface.
A shaft 43 is inserted into the inside of the clutch cam surface 42 and a roller 44 is assembled between the clutch cam surface 42 and the shaft 43.
4 is pressed in the biting direction between the clutch cam surface 42 and the shaft 43 by a pressing spring 45.

In the above structure, by appropriately setting the spring force of the pressing spring 45 and the angle of the clutch cam surface 42 on which the roller 44 acts, on/off torque can be generated for rotation of the shaft 43 in one direction. .

[Problem to be solved by the invention]

By the way, how to open and close the lid of a Western-style toilet! When raising the lid on the side or in the lid opening/closing mechanism of OA equipment,
A small torque is sufficient to allow smooth rotation, but when lowering the lid, a large torque is required to hold the lid so that it does not fall suddenly, and different holding torques are required for the forward and reverse rotation directions. is required.

In order to generate the necessary torque in such a lid opening/closing mechanism using a torque limiter with the above structure, the rotating shaft that opens and closes the lid must be equipped with at least two torque limiters that act in the forward and reverse rotational directions. , it is necessary to assemble a one-way clutch that switches the rotation of the rotating shaft, but this has the disadvantage that the opening/closing mechanism itself becomes larger due to the increased number of parts, and the manufacturing cost increases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a torque limiter that can set different torques for forward and reverse directions of rotation by itself, and that can make the torque transmission mechanism more compact.

[Means for Solving the Problems] In order to solve the above problems, a first means of the present invention provides a first outer ring around the shaft and a first outer ring fitted between the first outer ring and the shaft. Two outer rings are provided, and a plurality of first cam surfaces and second cam surfaces are formed on the inner peripheral surfaces of the first outer ring and the second outer ring, respectively, and the first cam surfaces and the second cam surfaces are respectively inclined in opposite directions with respect to the rotational direction of the shaft. between the surface and the outer peripheral surface of the second outer ring, and between the second cam surface and the shaft surface,
A rolling element is incorporated in each, and the rolling element is pressed by an elastic member between the first cam surface and the second outer ring, or between the second cam surface and the shaft.

Further, a second means of the present invention is to provide a first outer ring around the shaft and a second outer ring that fits between the first outer ring and the shaft,
A plurality of cam surfaces forming wedge-shaped spaces with respect to the outer peripheral surface of the second outer ring are formed on the inner peripheral surface of the first outer ring, and between the cam surface and the second outer ring, rolling elements and An elastic member is incorporated to press the rolling element in a direction to bite the rolling element between the cam surface and the second outer ring, and between the shaft and the inner circumferential surface of the second outer ring,
An engaging element that engages between the shaft and the second outer ring shaft and rotates them together when the shaft rotates in the biting direction of the rolling element, and an elastic member that presses the engaging element in the direction of engagement. We adopted a configuration that incorporates the following.

(Operation) In the first means described above, since the first cam surface and the second cam surface are inclined in opposite directions, the first cam surface and the second cam surface are inclined in opposite directions. One of the cam surfaces or the second cam surface locks and the other operates to generate on/off torque.

In this case, by changing the biting angle of the first cam surface and the second cam surface with respect to the rolling element and the spring force of the corresponding elastic member, different torques can be generated in the forward and reverse rotation directions. I can do it.

On the other hand, in the second means, when the shaft is rotated in the direction in which the engager engages, the shaft and the second outer ring rotate together. At this time, when the torque loaded on the first outer ring is larger than the limiter torque set by the cam surface and the rolling elements, the rolling elements slip between the first outer ring and the second outer ring, and no torque is transmitted. In the opposite case, the shaft, the second outer ring, and the first outer ring rotate together to transmit torque.

On the other hand, when the shaft rotates in the opposite direction to the above, the engager is not engaged, so the shaft idles with respect to the second outer ring and the first outer ring, and no torque is transmitted.

[Example〕 1 and 2 show an embodiment of the invention.

As shown in the figure, a small-diameter second outer ring 5 and a large-diameter first outer ring 4 are provided in parallel around a shaft 1 consisting of a rotating shaft 2 and an inner ring 3. A housing 6 is fitted onto the outer peripheral surface to fix the first outer ring 4.

On the inner circumferential surfaces of the first outer ring 4 and the second outer ring 5, a plurality of first cam surfaces 7 and second cam surfaces 8, which are inclined in a direction opposite to the rotational direction of the shaft 1, are provided along the circumferential direction. It is formed.

In this case, the first cam surface 7 forms a wedge-shaped space with respect to the outer peripheral surface of the second outer ring 5, and the second cam surface 8 forms a wedge-shaped space with respect to the surface of the shaft 1.

Between the first outer ring 4 and the second outer ring 5 and between the second outer ring 5 and the shaft 1, cages 9 and 10 are provided, and each cage S,
Rollers 11 and 12 as rolling elements are housed in the ten pockets 9a and 10a, respectively. Moreover, between each roller 11.12 and the holding surface 13.14 provided on the first outer ring 4 and the second outer ring 5, the roller 11.12 is connected to the first cam surface 7 and the second outer ring 5, or the holding surface 13.14 provided on the first outer ring 4 and the second outer ring 5, respectively. An elastic member 15, 16 is provided between the two cam surfaces 8 and the shaft 1 to press in the direction of biting.

One end of the first outer ring 4 and the second outer ring 5 is closed by a housing 6, and the other end is closed by a presser cover 17 that fits between the housing 6 and the shaft 1.

Further, the rotating shaft 2 and the inner ring 3 constituting the shaft 1 are coupled by a radial pin 18 so as to rotate together.

Note that the shaft 1 is not constructed in this way, and the inner ring 3 is
Alternatively, only the rotating shaft 2 may be incorporated into the second outer ring 5 without the above.

In the above structure, in the case of the first cam surface 7, when the second outer ring 5 rotates in the direction opposite to the arrow A, the roller 11 bites between the first cam surface and the second outer ring, When the rotation is transmitted to the second outer ring 5 and the second outer ring 5 rotates in the direction of the arrow A, the roller 11 moves to the wide part of the wedge-shaped space and the second outer ring 5 rotates in the direction of the arrow A.
will end up idling. In this case, by adjusting the rust angle of the first cam surface 7 and the spring force of the elastic member 15,
On/off torque can be set for the rotation of the second outer ring 5 in the direction of arrow A. For this reason, M1 cam surface 7
constitutes a one-way torque limiter with a reverse rotation prevention function that can set the torque when the roller is idling.

The same is true for the second cam surface 8, and the second cam surface 8 constitutes a one-way torque limiter that can set a torque with respect to the rotation of the shaft 1 in the direction of arrow B.

In this case, since the first outer ring 4 and the second outer ring 5 are separate members independent of each other, the wedge angle of the first cam surface 7 and the second cam surface 8 and the spring force of the elastic members 15 and 16 can be adjusted arbitrarily. can be varied, thereby allowing different limiter torques to be set.

The torque limiter of the embodiment has the above-described structure, and in order to be used in the opening/closing mechanism of the lid of a toilet or OA equipment, the limiter torque of the first cam surface 7 is set to a large torque value that can hold the lid, and The limiter torque of the second cam surface 8 is set to a small torque value that allows the lid to rotate smoothly, and the housing 6 and the lid are connected so that the rotation of the shaft 1 in the direction of arrow B coincides with the direction in which the lid is raised. .

In this state, when the lid is raised and the shaft 1 is rotated in the direction of arrow B, the second cam surface 8 and the roller 12 operate in a idling state, but the second outer ring 5 rotates due to the torque, and the first cam Since it is locked to surface 7, the lid has a second cam surface 8.
A small torque generated by the roller 12 is added to assist the operation of the lid.

Conversely, when the lid is lowered and the shaft 1 rotates in the direction opposite to the direction of arrow B, the second cam surface 8 locks, the second outer ring 5 rotates integrally with the shaft 1, and the outer roller 11 idles. Then, the first cam surface 7 is activated. Therefore, when operating the lid, a large torque is applied from the first cam surface 7, thereby preventing the lid from falling suddenly.

On the other hand, FIGS. 3 and 4 show a second embodiment.

In this example, the inclination of the second cam surface 26 of the second outer ring 23 is increased, and the spring force of the elastic member 32 is set to be strong.
A roller 30 is engaged between the second cam surface 26 and the surface of the shaft 21, and the two are set to rotate together.

In addition, the shaft 21 is made integral with the inner ring, and a locking part 33 is provided on the outer periphery of the cage 27 to rotate the cage integrally with the second outer ring 23. An elastic member 32 is housed in the recess 28.

Further, the roller 30 and the elastic member 32 installed between the second outer ring 23 and the shaft 1 are inserted into the housing 24 during rotation.
An inner lid 34 is provided to prevent the drawer from being pulled out.

In the above structure, as shown in FIG. 3, when the shaft 21 rotates clockwise, the roller 30 connects with the second cam surface 26 and
When the shaft 21 rotates counterclockwise, the roller 30 becomes uncoupled and the second outer ring 23 rotates idly. Therefore, the second cam surface 26
The rollers 30 and 30 transmit or interrupt torque with respect to the forward and reverse rotation of the shaft 21, and also constitute a launch.

On the other hand, the first cam surface 25 and the roller 2S constitute a one-way torque limiter that can set torque for clockwise rotation of the second outer ring 23, as in the first embodiment described above.

In the torque limiter configured as described above, when the shaft 21 rotates clockwise, the roller 30 is engaged and the clutch is engaged, and the shaft 21 and the second outer ring 23 rotate together.

In this case, when the load torque applied to the housing 24 from the outside is larger than the limiter torque set by the pressing force applied to the roller 29 from the elastic member 31, the roller 29 is connected to the first cam surface 25 and the second outer ring. overruns between 23 and 23.

Therefore, the second outer ring 23 slips and the torque of the shaft 21 is not transmitted.

Conversely, if the load torque is smaller than the limiter torque,
The roller 29 is pressed against the first cam surface 2 by the elastic member 31.
5 and the second outer ring 23, the shaft 21 and the second outer ring 2
3 and the first exporter 22 rotate together, and torque is transmitted.

On the other hand, when the shaft 21 rotates counterclockwise, the roller 3
0 is not engaged and the clutch is not established, the shaft 21 and the second outer ring 23 idle, and no torque is transmitted from the shaft 21.

Therefore, by using the above torque limiter, it is possible to arbitrarily set the transmission torque in one direction of rotation, but it is not possible to change it to a constant low transmission torque (torque when the clutch is slipping) in the opposite direction. , it is possible to switch to different torque values according to changes in rotation.

By the way, in the first embodiment described above, the roller 1
2 is inserted between the second cam surface 8 and the shaft 1 to generate the required limiter torque, an inner ring 3 whose outer diameter surface is formed with high dimensional accuracy is provided on the shaft 1, and the inner ring 3 is rotated. The second outer ring 23 and the shaft 21 are simply moved by the roller 30 by the action of the clutch, as in the second embodiment. The locking structure does not require high dimensional accuracy for the shaft 21, which eliminates the need for the inner ring, bottle, and bottle hole machining for the shaft, and has the advantage of being able to be manufactured at low cost. There is.

Note that the structure of the one-way launch in the second embodiment is not limited to the illustrated type.

That is, any one-way launch with low idling torque can be used, and sprags can also be used as engagement elements in place of the rollers 30.

(Effects of the Invention) As described above, the torque limiter of the present invention can independently set different transmission torques for forward and reverse rotations of the shaft, so different limiter torques are required depending on the rotation direction. When used in a rotation transmission mechanism, compared to conventional torque limiters that function only in one direction, it has the effect of reducing the number of parts and making the assembly space much more compact.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view of the first embodiment of the present invention, Fig. 2 is a longitudinal sectional side view thereof, Fig. 3 is a longitudinal sectional front view of the second embodiment, Fig. 4 is a longitudinal sectional side view thereof, and Fig. 5. is a longitudinal sectional front view of the conventional example,
FIG. 6 is a longitudinal sectional side view thereof. 1.21...shaft, 2...rotating shaft, 3...inner ring, 4.22...
・First outer ring, 5.23...Second outer ring, 7.25
......First cam surface, 8.26...Second cam surface, 9.10.27...Cage 11.12.2S, 30...・Roller, 15.1
6.31.32...Elastic body.

Claims (2)

[Claims] (1) A first outer ring and a second outer ring that fits between the first outer ring and the shaft are provided around the shaft, and the inner circumferential surfaces of the first outer ring and the second outer ring are respectively provided in the rotational direction of the shaft. A plurality of first cam surfaces and second cam surfaces are formed which are inclined in opposite directions to the outer ring, and a rolling element is provided between the first cam surface and the outer peripheral surface of the second outer ring, and between the second cam surface and the shaft surface. A torque limiter in which a rolling element is pressed by an elastic member in a direction to bite between the first cam surface and the second outer ring, or between the second cam surface and the shaft. (2) A first outer ring and a second outer ring that fits between the first outer ring and the shaft are provided around the shaft, and on the inner peripheral surface of the first outer ring,
A plurality of cam surfaces are formed to form a wedge-shaped space with respect to the outer peripheral surface of the second outer ring, and a rolling element is provided between the cam surface and the second outer ring, and the rolling element is connected between the cam surface and the second outer ring. An elastic member is installed between the shaft and the inner circumferential surface of the second outer ring, and the shaft is rotated in the direction in which the rolling elements are bitten, so that the shaft and the second outer ring shaft are pressed together. A torque limiter that incorporates an engaging element that engages between them and rotates them together, and an elastic member that presses the engaging element in the direction of engagement.