JPH0617837A - Torque limiter with automatic reset function - Google Patents

Abstract

PURPOSE:To enable the change of creep rotation of a holder by simple structural change in a torque limiter with automatic reset function constituted in such a way that both annular parts provided in relation to bearing rings and a holder are fitted in contact and creep is generated between both of them to decelerate the rotation of the holder. CONSTITUTION:A roller 18 to be engaged with a cylindrical face 8 and a polygonal cam face 12 is integrated into a holder 16 provided between an inner and an outer wheels 1, 2, and a rolling element 28 is pressed in between the inner wheel 1 and an annular member 19 connected to the holder 16. An annular part 21 to be fitted to the annular member 19 is formed at a clearance adjusting ring 4 thrusted into the outer wheel 1, and the fitting faces of both parts are formed into axial inclined faces 22, 23. In this structure, the annular member 19 rolls in internal contact around the annular part 21 so as to generate creep, but a fitting clearance generating the creep is changed by advancing/retreating the clearance adjusting ring 4 to change the rotating speed of the holder 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque limiter having a function of automatically returning.

[0002]

2. Description of the Related Art In a propeller propulsion machine of a small boat or a liquid compression circuit of a refrigerator compressor, when the driven side recovers to a normal state by disconnecting the power transmission on the driven side against overload on the driven side. Therefore, a torque limiter that returns to the original state and repeats torque transmission is required.

Further, in the above torque limiter, if the automatic return is repeated at extremely short time intervals while the prime mover side is rotating at a high speed, the follower side is forced to force a predetermined long time. A function that automatically returns at a time interval is required.

Conventionally, the applicant of the present invention has previously proposed a torque limiter which automatically returns at such a long interval as described in Japanese Patent Application No.
There is one proposed by -111281.

In this proposal, as shown in FIG. 7, a cylindrical surface 8 and a cam surface 12 composed of a polygonal leaf spring 11 are formed on the surfaces of the inner ring 1 and the outer ring 2 which are opposed to each other. The roller 18 that engages with the minimum clearance between the cylindrical surface 8 and the cam surface 12 is incorporated in the pocket of the cage 16 provided between the two.

Further, circular ring portions 31 and 32 are provided in relation to the cage 16 and the outer ring 2 to be fitted with a clearance, and the circular ring of the cage 16 is formed by the rolling element 28 press-fitted between the inner ring 1 and the cage 16. The part 31 is deformed in the radial direction so that the two annular parts 31, 32 are brought into contact with each other at a plurality of positions.

In the above structure, when the leaf spring 11 forming the cam surface 12 is deformed and the roller 18 passes through the engaging position, the cage 16 causes the circular load 32 of the outer ring 2 to move by the rotational load from the inner ring 1. Inscribed in the center, rolling and causing creep,
The roller 18 is moved to the next engagement position at a low speed.

[0008]

As described above, the torque limiter proposed above can repeat the cycle of torque transmission and cancellation at long time intervals. Now, let's change the time interval of automatic recovery. Then, it is necessary to change the distance between the positions where the rollers 18 are normally engaged.
However, since such a change in the engaging position requires changing the interval between the cam surfaces 12 and the interval between the rollers 18, the design of the shape of the leaf spring 11, the inner diameter surface of the outer ring 2, and the shape of the cage 16 are changed. However, there is a problem that the time and cost for the change increase.

Therefore, an object of the present invention is to provide a torque limiter capable of arbitrarily adjusting the time interval of automatic return with a simple structure.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention forms a cylindrical surface and a polygonal cam surface on opposing surfaces of inner and outer fitting races, and both races are formed. In the pocket of the cage installed between the two, the engaging element that engages with the minimum clearance of the cylindrical surface and the cam surface is provided, and the surface of the minimum clearance of the cam surface is made of an elastic material. A ring portion that is fitted to each other with a clearance is provided in relation to each of the bearing ring and the cage, and the ring portion that is related to the cage is eccentrically in the radial direction so that both of the ring portions roll in contact with each other. In the torque limiter with an automatic return function equipped with the eccentricity imparting means, the structure is provided with the clearance adjusting means for changing the fitting clearance between the both annular portions.

Further, as the clearance adjusting means, one of the both annular portions is provided so as to be movable back and forth in the axial direction toward the other,
That is, the fitting surfaces of the both annular portions are configured as inclined surfaces that are inclined in the axial direction.

[0012]

The function of the creep speed between the two annular parts that make contact rolling motion is proportional to the amount of eccentricity of the annular parts, that is, the size of the fitting clearance between the two annular parts. That is, when the fitting clearance (eccentricity amount) between both is δ and the circular constant is π, while one ring portion is inscribed or circumscribed about the other ring portion and makes one rotation, The one annular portion moves by an amount of δπ. Therefore, when the fitting clearance δ is changed, the creep rotation speed of the retainer is changed, and the time interval at which the engagement element automatically returns can be adjusted.

[0013]

1 to 6 show a torque limiter according to an embodiment. As shown in FIG. 1, an outer ring 2 has a threaded portion 3 formed at one end thereof, and a clearance adjustment ring 4 which also serves as a cover plate of an inner member is attached to the threaded portion 3 so as to be movable back and forth in the axial direction. There is. A bearing box 5 is press-fitted into the other end of the outer ring 2, and the inner ring 1 is inserted inside the bearing box 5 and the clearance adjusting ring 4. The inner ring 1 and the outer ring 2 are rotatably supported by bearings 6 and 7 incorporated between the adjusting ring 4 and the inner ring 1 and between the bearing box 5 and the inner ring 1, respectively. It is arranged coaxially by the guide.

The outer diameter surface of the central portion of the inner ring 1 is a cylindrical surface 8
And the inner diameter surface 9 of the outer ring 1 facing the cylindrical surface 8.
8 are formed with spring seats 10 at equal intervals in the circumferential direction, and leaf springs 11 forming a substantially octagonal rectangular ring are incorporated in each spring seat 10.

The leaf spring 11 is formed of spring leafs 11a divided into eight equal parts, and when assembled in the outer ring 2, the inner surface of each spring leaf 11a is between the cylindrical surface 8 of the inner ring 1. A cam surface 12 forming a wedge-shaped space is formed. Also,
The spring plates 11a are assembled with a slight interference fit between the spring seats 10 of the outer ring 2, and the spring plates 11a are not deformed between the spring plates 11a and the inner diameter surface 9 of the outer ring 2. An allowance 13 is provided. Furthermore, leaf spring 1
A protrusion 14 directed toward the cylindrical surface 8 of the inner ring 1 is formed in the center of the inner ring 1, and the minimum clearance 1 between the protrusion 14 and the cylindrical surface 8
The dimension a of 5 is set to be smaller than the outer diameter dimension d of the roller 18 described later.

An annular retainer 16 is provided between the leaf spring 11 and the cylindrical surface 8 of the inner ring 1, and a plurality of pockets are provided on the peripheral surface of the retainer 16 at equal intervals corresponding to the cam surface 12. 1
7 is provided, and a roller 18 as an engaging element is incorporated in each pocket 17 thereof.

This roller 18 is formed so that the outer diameter dimension d is smaller than the gap other than the minimum clearance 15 between the cam surface 12 and the cylindrical surface 8, and as shown in FIG.
Only in the vicinity of 5, the cam surface 12 and the cylindrical surface 8 are engaged. Further, the outer diameter dimension d of the roller 18 is set to be smaller than the gap formed between the leaf spring 11 and the cylindrical surface 8 when the leaf spring 11 bends toward the recess 13 side so that the roller 18 can pass through the gap. It has become.

The tip of the retainer 16 projects toward the bearing 6, and the projecting portion 16a is connected to an annular member 19 coaxial with the inner and outer rings. The annular member 19 has an uneven portion 20 provided on the inner diameter surface and the outer diameter surface of the protruding portion 16a.
And the retainer 16 are tightly fitted to the retainer 16, and the annular member 19 and the retainer 16 are immovable in the axial direction by the engagement, but relatively rotate with a predetermined torque in the rotating direction. Connected as much as possible.

On the other hand, on the inner surface of the clearance adjusting ring 4 which is attached to the tip of the outer ring 2 via the screw portion 3, an annular portion 21 which fits inside the annular member 19 is formed. The fitting surfaces of the annular portion 21 and the annular member 19 are inclined surfaces 22 and 23 that are inclined in the axial direction, respectively, as shown in FIG.
And a fitting clearance δ is provided between the inclined surfaces 22 and 23. In this structure, when the clearance adjusting member 4 is screwed into the threaded portion 3 of the outer ring 2 and is moved in the axial direction, the inclined surfaces 22 and 23 approach each other as shown in FIG. 6, and the fitting clearance δ changes. The fitting clearance δ is usually set to a value equal to or less than 1/300 of the nominal diameter D of the inner diameter of the annular member 19 and the outer diameter of the annular portion 21.

In FIG. 1, the clearance adjustment ring 4
The end surface 24 of the outer ring 2 is an insertion hole for an operating wrench.
At the end of the stop screw 25 for fixing the adjustment ring 4
Is installed.

The inner diameter surface of the annular member 19 and the inner ring 2
Circumferential grooves 26, 27 are formed on the outer diameter surface of each of them, and three rolling elements 28 made of steel balls or the like are press-fitted between the grooves 26, 27. Each rolling element 28
Are arranged at intervals of 120 degrees in the circumferential direction by the ball retainer 29, and rollingly guide the annular member 19 with respect to the inner ring 1 by rolling on the circumferential grooves 26, 27. Further, by press-fitting the rolling elements 28, the annular member 19 is deformed with each rolling element 28 as an apex as shown in FIG. 3, and the deforming member 30 makes point contact or line contact with the annular portion 21 integrated with the outer ring 2. It comes in contact.

The torque limiter of this embodiment is constructed as described above, and the inner ring 1 is connected to the prime mover side, and the outer ring 2 is connected to the driven side. As shown in FIGS. 8 and the cam surface 12 of the leaf spring 11 are fixed to the outer ring 2 with the roller 18 abutting, and the inner ring 1 is rotated in the direction of the arrow, the roller 18 is engaged with the cylindrical surface 8 and the cam surface 12, and the clutch is opened. When established, the outer ring 2 rotates integrally with the inner ring 1.

From this state, when the torque applied to the outer ring 2 becomes large, the cam surface 12 of the rectangular ring-shaped leaf spring 11 forming the clutch is bent toward the recess 13 as shown in FIG. When it continues, the roller 18 passes through the minimum clearance portion 15 and is discharged to the opposite side of the cam surface 12 and loses the clutch function.

When the prime mover side continues to rotate while the above torque transmission is released and the inner ring 1 and the outer ring 2 rotate relative to each other,
When the annular member 19 comes into contact with the annular portion 21, the annular portion 2
Inward rolling motion centered on the outer diameter of No. 1 causes creep. That is, while the annular member 19 makes one revolution of the annular portion 21, the annular member 19 relatively rotates by an amount πδ obtained by multiplying the fitting clearance δ by the circumferential ratio π.

The rotation direction of this creep is the same as the rotation direction of the inner ring 1 due to the inscribed rolling, and the rotation number of the creep, that is, the rotation number Nc of the cage 16 is the rotation number of the inner ring 1 is N. The pitch circle diameter of the moving body 28 is D _P , and the rolling body 28 is
If the diameter of D is D _W , it is expressed by the following equation. N _C = (δ / D) × {(D _P −D _W ) / (2 × D _P )} × N ...... In this case, the value of the fitting clearance δ is 1 / of the nominal diameter D as described above. Since the value is set to 300 or less, the cage 1
6 rotates at a rotational speed of 1/600 or less with respect to the rotational speed of the inner ring 1. Therefore, after the driven side (outer ring) stops due to an abnormal situation, the roller 18 reaches the next engagement position after a long time, and the cycle of automatic return with a sufficient time margin is repeated. be able to.

On the other hand, here, the clearance adjusting member 4 is attached to the outer ring 2
Screw inside the sloping surface, as shown in FIG.
When the fitting clearance is set to δ / 2 by bringing them close to each other, the creep rotation speed of the retainer 16 becomes 1/2 of the rotation speed Nc from the relationship of the above equation. Therefore, the roller 18 moves toward the next engagement position at half speed, and the time required to reach the engagement position is doubled.
As described above, the time until the roller automatically returns increases or decreases in proportion to the size of the fitting clearance δ. Therefore, by moving the clearance adjustment ring 4 forward and backward, the time interval for automatic return can be freely changed. it can.

In the above structure, since the clearance adjusting ring 4 is movably attached to the end portion of the outer ring 2 via the screw, a simple modification from the conventional structure is required, and the shapes of the leaf spring 11 and the cage 16 are changed. It is possible to modify the torque limiter at low cost as compared with the method of changing the cam surface 12 and the distance between the rollers 18 by changing the above.

In the above example, the inner ring 1 is on the drive side and the outer ring 2 is on the driven side, but conversely, the outer ring 2 is on the drive side and the inner ring 1 is on the drive side.
Even if is set to the driven side, the same effect as described above can be obtained. In this case, the stationary side inner ring 1 is provided with a circular ring portion 21 that fits with the circular ring member 19 connected to the retainer 16, and the circular ring member 19 is provided between the rotary side outer ring 2 and the circular ring member 19. The rolling element 28 that deforms is pressed.

[0029]

As described above, according to the present invention, since the fitting clearance between the cage that generates creep and the ring portion of the bearing ring is changed, it is possible to change the shape of the cam surface and the interval between the engaging elements. The creep rotation speed of the cage can be changed, and there is an effect that the time interval of automatic restoration can be freely adjusted by a simple structure change and 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 sectional view showing a clutch portion of the above.

FIG. 5 is an enlarged cross-sectional view showing a creep occurrence portion of the above.

FIG. 6 is a cross-sectional view showing the operating state of FIG.

FIG. 7 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Inner ring 2 Outer ring 4 Clearance adjusting ring 8 Cylindrical surface 11 Leaf spring 12 Cam surface 16 Cage 18 Roller 19 Ring member 21 Ring part 22, 23 Inclined surface 28 Rolling element δ Fitting clearance

Claims (2)

[Claims] 1. The surface of the bearing ring that fits inside and outside,
A cylindrical surface and a polygonal cam surface are formed, and an engaging element that engages with the minimum clearance between the cylindrical surface and the cam surface is provided in the pocket of the retainer that is installed between the two bearing rings. The surface of the minimum clearance of the surface is made of elastic material, and the annular ring part that is related to the driven side race and the cage is fitted to each other with a gap. In a torque limiter with an automatic return function, which is provided with an eccentricity imparting means for eccentrically eccentrically rolling the two annular portions in contact with each other, a gap adjusting means for changing a fitting gap of the both annular portions is provided. A characteristic torque limiter with an automatic return function. 2. The clearance adjusting means is provided so that one of the two annular portions can be moved back and forth in the axial direction toward the other, and the fitting surfaces of the both annular portions are inclined surfaces inclined in the axial direction. The torque limiter with an automatic return function according to claim 1, wherein the torque limiter is configured.