JPH06313441A - Torque limiter provided with automatic return function - Google Patents

Abstract

PURPOSE:To facilitate the assemblage and the adjustment by simplifying the structure of a mechanism for returning, in a torque limiter automatically returning at long intervals. CONSTITUTION:A cage 4 of a roller is slidably attached to a guide roller bearing 19 attached to an inner race 1, and the cage 4 is made eccentric motion by revolution of the guide roller bearing 19. A great number of elastic members 22 are arranged on the outer periphery of the cage 4, so as to be inclined in the inner race rotating direction. When the cage 4 is made eccentric according to the rotation of the inner race 1, the difference of feeding force to act on the cage 4 from the elastic members 22 is generated between the eccentric parts of the outside diameter direction and the inside diameter direction, and the cage 4 is rotated in the direction same as that of the inner race at low speed by the difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque limiter that repeats automatic return at long time intervals.

[0002]

2. Description of the Related Art In general industrial machines, in order to prevent a fatal accident of the machine, the power transmission on the prime mover side is disconnected from the overload on the driven side, and when the driven side is restored to a normal state, it is automatically In some cases, a torque limiter that returns to the original state and repeats power transmission may be incorporated. In this torque limiter, if the motor side is rotating at a high speed and the automatic return is repeated at extremely short time intervals, the driven side will be forced to force the automatic return after a predetermined long time interval. Function is required.

Conventionally, as shown in FIGS. 12 and 13, a torque limiter which automatically returns at a long time interval as described above has been proposed.

The proposed torque limiter is provided with cylindrical surfaces 33 and engaging surfaces 34 formed on each side of a polygonal leaf spring 35 on the surfaces of the inner ring 31 and the outer ring 32 which are opposed to each other.
A roller 37 that engages with the smallest clearance between the cylindrical surface 33 and the engaging surface 34 in the pocket of the cage 36 provided between the first and the second 32.
Is incorporated.

Further, annular parts 38 and 39 provided so as to rotate together with the retainer 36 and the outer ring 32 are fitted with a slight gap, and are held by a rolling element 40 press-fitted between the inner ring 31 and the retainer 36. The annular portion 38 on the container 36 side is deformed in the radial direction so that both annular portions 38, 39 are in contact at a plurality of positions.

In the above structure, the leaf spring 35 forming the engagement surface 34 is deformed by the overload on the driven side, and when the roller 37 passes the engagement position, the cage 36 is rotated by the rotational load from the inner ring 31. Inward rolling around the annular portion 39 on the outer ring 32 side causes creep, and the roller 37 is moved to the next engagement position at a low speed. As a result, the torque transmission state is automatically restored after a long time interval, and this is repeated.

[0007]

In the above proposed torque limiter, the mechanism for returning the torque limiter again is as follows.
It has a structure in which a plurality of rolling elements 40 and their retainers are assembled between the annular portions 38, 39 fitted with each other with a slight gap. At the time of assembling, the diameters of the annular portions 38, 39 are properly adjusted. It is molded with high precision so that a press-fitting margin can be obtained, and its annular portion 3
Since the work of press-fitting the rolling element 40 between 8 and 39 is required, there is a problem in that the structure is complicated and it is easy to assemble and adjust.

Therefore, an object of the present invention is to provide a torque limiter with an automatic return function, which solves the above problems, simplifies the structure of the mechanism for re-return, and can easily perform assembly and adjustment work. There is.

[0009]

In order to solve the above problems, according to the present invention, one side is a driving side and the other side is a driven side.
Two races are fitted inside and outside, one of the facing surfaces of both races is formed with a cylindrical surface, and the other is formed with an engagement surface. A cylindrical surface and an engaging element that engages with the engaging surface are incorporated, and a surface of the engaging surface or a bearing ring having the engaging surface is formed to be elastically deformable, and between the cage and the driving-side bearing ring. A means for converting the rotation of the bearing ring into an eccentric movement of the cage, and a plurality of elastic bodies arranged in the circumferential direction at a uniform density so as to face the inside or the outside of the cage. An arc connecting the tip of the elastic body is formed concentrically with the drive wheel on the drive side, and has a diameter dimension such that when the cage is eccentric, at least one elastic body comes into contact with the peripheral surface of the cage. The structure is such that the tip of each elastic body is inclined at a minute angle in the circumferential direction with respect to the cage.

[0010]

In the above structure, with the engagement element engaged with the cylindrical surface and the engagement surface, an overload acts on the driven side, the engagement element passes through the engagement position, and the drive-side bearing ring is When spinning idle,
The rotation of the bearing ring is converted into an eccentric movement of the cage.

Due to the eccentric movement of the cage, the peripheral surface of the cage on the eccentric side strongly contacts the elastic body, but since the tip of the elastic body is inclined in the circumferential direction with respect to the cage, the wedge effect is obtained. As a result, the cage is sent out in the inclination direction of the elastic material without slipping. On the other hand, the peripheral surface of the cage on the side opposite to the eccentricity separates from the elastic body or is in weak contact, so that slippage occurs at the contact position and almost no feed force acts on the cage.

Due to the difference in the feed force acting on the peripheral surface of the retainer, the retainer rotates by a slight amount in the inclination direction of the elastic material, and the engaging element is moved to the next engaging position over a long time. .

[0013]

1 to 5 show a torque limiter with an automatic return function according to an embodiment. As shown in FIGS. 1 and 2, the inner ring 1 has an outer diameter surface formed by a cylindrical surface 7, and a hole 8 with a key groove into which an input shaft is inserted is provided in a central portion.

The outer ring 2 fitted to the outer side of the inner ring 1 has a crack 9 extending from the inner diameter surface to the outer diameter surface at one location on the peripheral surface, and the outer ring is elastically deformable in the radial direction by the separation of the peripheral surface. Is given. Also, on the inner diameter surface of the outer ring 2,
Eight recesses 10 are formed at equal intervals, and the seven recesses 1
An engagement surface 11 that is inclined in the circumferential direction is formed on the bottom surface of 0. Each of the engaging surfaces 11 forms a wedge-shaped cavity 12 with the cylindrical surface 7 of the inner ring 1.

An annular cage 4 is installed between the engaging surface 11 and the cylindrical surface 7 in a radial direction with a predetermined clearance. The cage 4 is formed in a comb tooth shape, and eight pockets 13 are formed at one end of the cage 4 so as to correspond to the recesses 10 of the outer ring 2, and the pockets 13 serve as engaging members, respectively. Roller 3 is incorporated.

As shown in FIG. 5, the diameter d of the roller 3 is smaller than the wide portion 12a of the wedge-shaped cavity 12 formed by the cylindrical surface 7 and the engaging surface 11 and larger than the narrow portion 12b. The roller 3 is formed so as to engage with the cylindrical surface 7 and the engaging surface 11 only near the narrow portion 12b.

The size of the gap between the inner ring 1 and the outer ring 2 other than near the narrow portion 12b is the diameter d of the roller 3.
It is formed to have a larger size, and has a size that allows the roller 3 to move without resistance.

A casing 5 is fitted on the outer side of the outer ring 2, and a lid member 6 is integrally connected to an end surface of the casing 5 with a bolt 14. The casing 5 and the lid member 6 are rotatably supported by bearings 15 arranged at both ends of the inner ring 1. Further, a torque transmitting recess 16 is formed on the inner side surface of the casing 5, and the recess 1
A protrusion 17 for torque transmission combined with 6 is formed on the side surface of the outer ring 2, and a bolt hole 18 for mounting the output shaft is formed on the outer side surface of the lid member 6.

On the other hand, a guide roller bearing 19 is attached to the end surface of the inner ring 1, and the inner peripheral surface of the cage 3 is in sliding contact with the outer peripheral surface of the guide roller bearing 19. The center position of the guide roller bearing 19 is set so that the cage 4 rotates eccentrically with respect to the rotation center of the inner ring 1. In this structure, the guide roller bearing 19 is rotated along with the rotation of the inner ring 1.
Revolving, the guide roller bearing 19 causes the retainer 4 to be eccentric while rotating, and the retainer 4 performs only eccentric movement with almost no rotational force transmitted.

A braking spring 20 is attached to the inner diameter surface of the casing 5 facing the outer peripheral surface of the cage 4. As shown in FIGS. 6 and 7, the braking spring 20 is formed by punching U-shaped tongue pieces on the inner peripheral surface of a cylindrical spring plate member 21 at regular intervals by a press or the like. Each of the tongue pieces protruding inward forms an elastic body 22 that is evenly arranged on the outer circumference of the cage 4.

Each of the elastic bodies 22 corresponds to the outer ring 2 described above.
Is formed to be inclined in the same direction as the inclination direction of the engaging surface 11, and the arc 23 connecting the tips of the elastic bodies 22 is concentric with the center of rotation of the inner ring 1 and at least when the cage 4 is eccentric. The size of one elastic body 22 is set so as to contact the peripheral surface of the cage 4. In addition, the inclination angle β of each elastic body 22 is such that when the cage 4 is eccentrically contacted, the wedge portion generated between the inclined elastic body 22 and the peripheral surface of the cage 4 prevents the contact portion from slipping. It is set to an angle.

A braking spring 20 forming the elastic body 22 described above.
The outer diameter surface is integrated with the inner diameter surface of the casing 5 by adhesion or the like, and is fixed so as not to rotate.

The torque limiter of this embodiment has the above-mentioned structure, and the input shaft is inserted into the hole 8 of the inner ring 1 and the output shaft is attached through the bolts attached to the bolt holes 18 of the lid member 6 for input. The inner ring 1 is rotated by the shaft.

Now, when the inner ring 1 is rotated in the direction of the arrow in FIG. 5, the roller 3 causes the narrow portion 12b of the wedge-shaped cavity 12 to move.
The outer ring 2 rotates integrally with the inner ring 1 and the torque of the outer ring 2 is transmitted to the output shaft via the casing 5 and the lid member 6.

From this state, if the load acting on the output side (outer ring 2 side) increases, the outer ring 2 expands in diameter because the peripheral surface of the outer ring 2 is separated by the cracks 9, and the amount of biting of the roller 3 is increased. Will increase.

Further, when the load applied to the output shaft increases and the roller 3 passes through the narrow portion 12b of the wedge-shaped cavity 12, the roller 3 cannot transmit torque and the inner ring 1 idles, resulting in input. Torque is not transmitted from the shaft to the output shaft.

As described above, when the transmission torque exceeds the transmission cutoff torque and the inner ring 1 idles, the guide roller bearing 19 revolves, and the retainer 4 eccentrically moves accordingly.

At this time, in the portion where the cage 4 is eccentric in the outer diameter direction, as shown in FIG. 8, the amount of bending of the elastic body 22 in contact with the peripheral surface of the cage 4 increases and the contact force also increases. In this case, since each elastic body 22 is inclined in the rotation direction of the inner ring 1, the cage 4 is not slipped at the contact position due to the wedge effect, and is sent out in the rotation direction of the inner ring 1 which is the deformation direction of the elastic body 22.

On the other hand, in the portion where the cage 4 is eccentric in the inner diameter direction, when the cage 4 is about to be sent out in the opposite direction to the above due to the same phenomenon as described above, the cage 4 as shown in FIG. 4 separates from the elastic body 22, the amount of bending of the elastic body 22 is reduced, and the contact force is also reduced, so that slight slippage occurs at the contact position.

Therefore, a difference occurs in the feeding force of the elastic body 22 between the portion of the cage 4 that is eccentric in the outer diameter direction and the portion that is eccentric in the inner diameter direction.
Move in the direction of rotation.

The above-described action similarly occurs in all the elastic bodies 22, and the cage 4 gradually rotates in the rotational direction of the inner ring 1 with eccentric movement. With the rotation of the cage 4,
The roller 3 moves in the rotation direction of the inner ring and reaches the next wedge-shaped void 12 over a certain period of time.

Then, again, the roller 3 has the wedge-shaped void 12
When it goes into the lock state, it becomes a locked state and the torque can be transmitted. When the transmitted torque exceeds the transmission cutoff torque, the same operation as described above is repeated.

The time until the above-mentioned re-restoration can be arbitrarily adjusted by adjusting the amount of interference between the peripheral surface of the cage 4 and each elastic body 22.

On the other hand, FIGS. 10 and 11 show another embodiment. In this example, the mechanism for returning the torque limiter again has the same structure as that of the above-described embodiment, and the structure using the leaf spring described in the section of the prior art is adopted for the torque limiter mechanism itself.

That is, a polygonal leaf spring 35 is incorporated on the inner diameter side of the outer ring 2, and an engaging surface 34 with which the roller 3 engages is formed on the inner surface of each side of the leaf spring 35. Further, a recess 41 is provided on the inner diameter surface of the outer ring 2, and when the transmission torque exceeds the transmission cut-off torque, the roller 3 elastically deforms the leaf spring 35 toward the recess 41, so that the space between the engagement surface 34 and the cylindrical surface 33 is separated. I'm trying to pass.

Since other structures and operations are the same as those of the above-mentioned embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted.

In the above embodiment, the inner ring 1 is set to the driving side and the outer ring 2 is set to the driven side. However, conversely, load torque may be applied to the inner ring side to rotate from the outer ring side. Similar effects can be obtained.

[0038]

As described above, the torque limiter of the present invention is
Since it is only necessary to place an elastic material on the peripheral surface of the cage that moves eccentrically, and the re-recovery time can be adjusted by adjusting the amount of interference between the cage and the elastic body, compared to the conventional structure using creep. And the structure of the return mechanism is simplified,
Assembling and adjusting operations are facilitated, and there is an effect that it is possible to form a highly accurate re-return operation at low cost.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a torque limiter of an embodiment.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged cross-sectional view showing a main part of FIG.

FIG. 5 is an enlarged sectional view showing a clutch portion of the above.

FIG. 6 is a front view of a braking spring.

FIG. 7 is a side view of the above.

FIG. 8 is a diagram showing a working state of the embodiment.

FIG. 9 is a diagram showing an operating state of the above.

FIG. 10 is a vertical sectional front view showing another embodiment.

11 is a sectional view taken along line XI-XI of FIG.

FIG. 12 is a vertical sectional front view showing a conventional example.

13 is a sectional view taken along line XIII-XIII in FIG.

[Explanation of symbols]

 1 Inner ring 2 Outer ring 3 Roller 4 Cage 5 Casing 6 Lid member 7, 33 Cylindrical surface 11, 34 Engaging surface 12 Wedge-shaped void 13 Pocket 19 Guide roller bearing 20 Braking spring 22 Elastic body 35 Leaf spring 41 Recess

Claims (2)

[Claims] Claims: 1. Two bearing rings, one of which is a driving side and the other of which is a driven side, are fitted inside and outside, and a cylindrical surface is formed on one of opposing surfaces of the two bearing rings and an engagement surface is formed on the other surface. , A retainer pocket provided between the two raceways is provided with an engaging element for engaging the cylindrical surface and the engagement surface, and the raceway having the engagement surface or the engagement surface is elastically deformed. A means for converting the rotation of the bearing ring into an eccentric movement of the retainer is provided between the retainer and the drive-side bearing ring so as to face the inside or outside of the retainer in the circumferential direction. Is provided with a large number of elastic bodies arranged at a uniform density, and the arc connecting the tips of the elastic bodies is concentric with the drive wheel on the drive side and at least with the peripheral surface of the cage when the cage is eccentric. The diameter of each elastic body is such that one elastic body comes into contact with the tip of each elastic body in the circumferential direction with respect to the cage. Torque limiter with automatic return function that is tilted at a very small angle. 2. The torque limiter with an automatic return function according to claim 1, wherein the elastic body is formed by partially punching a peripheral surface of a cylindrical leaf spring in a radial direction.