JPH0650358A - Torque limitter equipped with automatic reset function - Google Patents

Abstract

PURPOSE:To immesiately transmit torque in the normal and reverse revolution directions, as for a torque limitter equipped with automatic reset function for carrying out the torque transmission by the engagement of an engagement element between a cam surface made of elastic member and a cylindrical surface. CONSTITUTION:A cylindrical surface 5 is formed on an inner race 1, and a cam surface 9 consisting of a polygonal leaf spring 7 is formed on an outer race 2, and a roller 13 is assembled in a retainer 14 installed between the inner and outer races. A recessed place 10 for the fitting of the roller 13 is formed at the center of each side of the leaf spring 7, and each min. gap (a), (a) for the engagement of the roller is formed on both the sides of the recesed place 10. With this structure, a torque is transmitted when the leaf spring 7 is deformed and the roller 13 slips off from the recessed place 10, and after the roller 13 slips off from the recessed place 10, the retainer 14 performs rolling movement around the annular part of the outer race 2, and a creep is generated, and the roller 13 is shifted to the next recessed place at a low speed.

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 ship or a hydraulic circuit of a refrigerator compressor, when the driven side is restored to a normal state by disconnecting the power transmission on the driven side against an overload on the driven side, Therefore, a torque limiter that returns to the original state and repeats torque transmission is required.

Further, in the torque limiter described above, 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 FIGS. 8 and 9, a cylindrical surface 5 and a cam surface 9 composed of a polygonal leaf spring 7 are formed on the surfaces of the inner ring 1 and the outer ring 2 facing each other. Inner and outer rings 1,
A roller 13 that engages with the minimum clearance between the cylindrical surface 5 and the cam surface 9 is incorporated in the pocket of the cage 14 provided between the two.

Further, the retainer 14 and the outer ring 2 are provided with annular portions 30 and 31 to be fitted respectively with a clearance, a rolling element 32 is incorporated between the inner ring 1 and the retainer 14, and the retainer is press-fitted into the retainer. 14 is rolled and guided, and the annular portion 30 is deformed in the radial direction so that the annular portions 30 and 31 are brought into contact with each other at a plurality of positions.

In the above structure, when the leaf spring 7 forming the cam surface 9 is deformed and the roller 13 passes the engagement position, the cage 14 is attached to the annular portion 31 of the outer ring 2 by the rotational load from the inner ring 1. On the other hand, the roller 13 makes a rolling motion to cause creep, and the roller 13 is moved to the next engagement position at a low speed.

[0008]

In the structure proposed above, the inner ring 1 is moved in the direction of the arrow from the state where the roller 13 is in contact with the cam surface 9 and the cylindrical surface 5 as shown in FIG. 9, that is, the minimum clearance portion. When the roller 13 rotates in the direction toward, the roller 13 immediately engages and torque can be transmitted to the outer ring 2. However, when the roller 13 rotates in the opposite direction, the roller 13 moves to the next engagement position at a low speed due to the creep phenomenon. ,
It takes a long time to transmit the torque. However, some types of torque limiters may be required to have a function that can immediately transmit torque to the driven side regardless of whether the drive side rotates in the forward or reverse direction.The above characteristics apply to those limiters. There is a problem in doing.

Therefore, according to the present invention, the torque can be immediately transmitted to the driven side in response to the rotation of the drive side in the forward and reverse directions, and further, after the torque transmission state is disconnected, the torque is transmitted again at a long time interval. It is an object of the present invention to provide a torque limiter that can be repeatedly activated.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cylindrical surface on one of the facing surfaces of a bearing ring fitted inside and outside, and a circular surface on the other side in the circumferential direction with respect to the cylindrical surface. A plurality of inclined cam surfaces are formed, and an engaging element that engages with the narrow portion of the cylindrical surface and the cam surface is incorporated in the cage provided between the both races, and the surface of each cam surface is elastic. In a torque limiter with an automatic return function, which is formed of a material, and is connected to a speed reducer that reduces the rotation of the drive-side bearing ring and transmits the speed to the cage, the surface of the elastic material of each cam surface is
A recess is provided in which the engaging element fits, and narrow portions are formed on both sides of the recess so that the engaging element engages with the cylindrical surface.

[0011]

In the above structure, when the engaging element is fitted in the recess and the engaging element moves in either forward or reverse direction, the engaging element engages with the narrow portions on both sides of the recess to transmit torque. Be done.

When the engaging element passes through the narrow portion,
The retainer is guided to the next recess, but the retainer is decelerated by the decelerating means with respect to the drive-side orbital ring to be rotationally driven, so that the engaging element moves at a low speed and takes a long time. Move to the next recess.

[0013]

1 to 3 show a torque limiter according to an embodiment. As shown in FIGS. 1 and 2, one end of the inner race 1 and the outer race 2 is rotatably supported by the bearing 3 and the engaging member 18, and the other end is rotatably supported by the bearing 4 and the bearing housing 23. Four
It is held coaxially by the guide.

The outer diameter surface of the central portion of the inner ring 1 is formed by a cylindrical surface 5, and the notch 6 is formed at eight locations at equal intervals in the circumferential direction on the inner diameter surface of the outer ring 2 facing the cylindrical surface 5. Has been done,
A leaf spring 7 having a substantially octagonal ring shape is incorporated in each notch 6.

The leaf spring 7 is formed of eight equally divided spring plates 8. The inner surface of each spring plate 8 forms a wedge surface with the cylindrical surface 5 of the inner ring 1 to form a cam surface. 9 is formed. The spring plates 8 are assembled in a slightly interference fit between the notches 6 of the outer ring 2, and the spring plates 8 are deformed between the spring plates 8 and the inner diameter surface of the outer ring 2. Is provided to allow the above.

A recess 10 is formed at the center of each spring plate 8 so as to be bent in a mountain shape toward the outer ring 2, and a roller 13 as an engaging member, which will be described later, is fitted into the recess 10. Has become. The inner surface of the recess 9 has inclined surfaces 11 and 1 inclined in opposite directions at an angle θ with respect to the circumferential direction.
2, each spring plate 8 is slightly bent in a state where the roller 13 is fitted between the inclined surfaces 11 and 12 and the cylindrical surface 5, and the roller 13 is pressed toward the inner ring 1 by the elastic force. . Further, the minimum clearances a, a between the cam surface 9 and the cylindrical surface 5 are provided between both sides of the recess 10 and the cylindrical surface 5.
Are formed, and the dimensions of the minimum clearances a, a are set to be smaller than the diameter dimension of the roller 13.

A retainer 14 is provided between the leaf spring 7 and the cylindrical surface 5, and a large number of pockets 15 are provided on the peripheral surface of the retainer 14 at equal intervals corresponding to the cam surface 9. And each of the pockets 15 has a roller 13 as an engaging member.
Is incorporated.

The outer diameter dimension d of the roller 13 is formed smaller than the minimum clearance a between the cam surface 9 and the cylindrical surface 5, and only in the vicinity of the minimum clearance a is the cam surface 9 and the cylinder. It is adapted to engage the surface 5 and also the spring plate 8
Is set to be smaller than the gap formed between the spring plate 8 and the cylindrical surface 5 when it bends to the side of the roller 24, and the gap is set to the roller 1
3 can pass through.

The tip of the retainer 14 projects toward the bearing 3, and the projecting portion has a circular ring member 16 coaxial with the inner and outer rings.
Are connected. The annular member 16 is tightly fitted to the retainer 14 by fitting the inner diameter surface and the uneven portion 17 provided on the outer diameter surface of the protruding portion, and is retained by the fitting to the annular member 16. The device 14 is immovable in the axial direction, but is connected so as to be relatively rotatable with a predetermined torque in the rotational direction.

An engaging member 18 having an L-shaped cross section is integrally press-fitted at the tip of the outer ring 2, and the engaging member 1
8, an annular portion 19 fitted inside the annular member 16
Are formed.

The annular member 16 and the annular portion 19 are fitted with each other through a slight clearance δ, and the fitting clearance δ.
Is set to a value of several hundredths or less of the nominal diameter dimension D of the inner diameter dimension of the annular member 16 and the outer diameter dimension of the annular portion 19.

On the other hand, a cylindrical roller bearing 20 is incorporated between the annular member 16 and the cylindrical surface 5 of the inner ring 1 as shown in FIGS. The cylindrical roller bearing 20 is composed of an annular roller cage 21 and three cylindrical rollers 22 arranged by the roller cage 21 at intervals of 120 degrees in the circumferential direction. The container 14 is rotationally guided with respect to the inner ring 1.

The diameter of the cylindrical roller 22 is larger than the distance between the annular member 16 and the inner ring 1, so that each cylindrical roller 22 is assembled between the annular member 16 and the inner ring in a press-fitted state. It is set, and by press fitting the cylindrical roller,
The annular member 16 is deformed with the cylindrical roller 22 as an apex, and the annular member 16 comes into line contact with the annular portion 19 of the outer ring 2 at the deformed portion.

The torque limiter of this embodiment has the structure as described above, and its operation will be described below.

The inner ring 1 is connected to the prime mover side, and the outer ring 2 is connected to the driven side. With the rollers 13 fitted in the recesses 10 of the leaf spring 7 as shown in FIGS. When the inner ring 1 is rotated counterclockwise, the roller 13 is engaged with the inclined surface 11 on the left side of the recess 10 and the cylindrical surface 5 to establish a clutch having a Strat angle θ, and the outer ring 2 is integrated with the inner ring 1. To rotate. On the contrary, when the inner ring 1 rotates clockwise from the state of FIG. 5, the roller 13 is caught between the cylindrical surface 5 and the inclined surface 12 on the right side of the recess 10, and the clutch having the strut angle θ is established. That is, regardless of whether the inner ring 1 rotates in the left or right direction, the clutch is established and torque can be immediately transmitted to the outer ring 2.

When the torque applied to the outer ring 2 is increased from the above-mentioned engaged state of the clutch, the leaf spring 7 bends toward the recess 24 as shown in FIG. 6, and the torque that can be applied decreases as the strut angle θ decreases. Then, when the overload continues, the roller 13 passes through the minimum clearance portion a and is discharged to the outside of the recess 10 acting as a clutch, and the clutch function is lost.

A movement of the discharged roller 13 in the circumferential direction is restricted by a retainer 14, and the retainer 14 comes into contact with the outer ring 2 via an annular member 16 and an annular portion 19 to be freely rotated. Therefore, the roller 13 and the cage 14 do not rotate together with the rotation of the inner ring 1.

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,
The rotating load of the inner ring 1 is passed through the cylindrical rollers 22 and the annular member 16
Be transmitted to. Therefore, the annular member 16 is the annular portion 1 of the outer ring 2.
Inward rolling motion centering around the outer diameter of 9 causes creep. That is, the inside of the annular member 16 is
When the circle makes one round, the annular member 16 and the annular portion 19 relatively rotate by an amount πδ obtained by multiplying the fitting clearance δ by the pi. In this case, since the value of the fitting clearance δ is set to a small value as described above, the cage 14 rotates at a low speed relative to the rotation of the inner ring 1, and the roller 13 is rotated by a small distance per rotation. To move. For this reason, after the driven side has stopped due to an abnormal situation, the roller 13 reaches the next engagement position after a long time, and automatic restoration with a sufficient time margin can be repeated.

On the other hand, when the roller 13 reaches the next recess 10 and the torque transmission is changed from the released state to the connected state, the roller 13 once passes through the minimum clearances a on both sides of the recess 10. Sometimes it transmits some torque. Then, when the roller 13 enters the recess 10 and comes out of the recess 10, a regular torque transmission capability is obtained and a predetermined torque is transmitted. Therefore, the roller 13 has a cushion-like torque transmission capacity before transmitting the torque at the regular position (the position where the roller 10 exits the recess 10), and the torque can be gradually increased to be transmitted, so that the torque can be smoothly transmitted. Can communicate.

FIG. 7 shows another embodiment. In this example, the leaf spring 7 is formed of a spring plate 8a facing the roller 13 and a spring plate 8b incorporated on the back surface thereof. Further, a recess 10 into which the roller 13 is fitted is formed in the inner spring plate 8a, and the outer spring plate 8b is brought into contact with the back surface of the recess 10.

In this structure, since the elastic force of the entire leaf spring 7 can be increased by the two spring plates 8a and 8b, the torque transmission capability can be increased.

In each of the above-mentioned embodiments, the inner ring 1 is on the driving side and the outer ring 2 is on the driven side. Conversely, if the outer ring 2 is on the driving side and the inner ring 1 is on the driven side, the same operation as described above is achieved. Obtainable. Further, two or four or more cylindrical rollers 22 may be incorporated at equal intervals.

[0033]

As described above, according to the present invention, the surface of the elastic material forming the cam surface is provided with the recess into which the engaging member is fitted, and the torque is transmitted when the engaging member comes out of the recess. Therefore, the torque can be immediately transmitted to the driven side regardless of the rotation of the drive-side bearing ring in any direction.

When the torque transmission is released,
Since the engaging element moves at a low speed by the deceleration means, it is possible to restart at a long time interval and to repeat the automatic return with a time margin.

[Brief description of drawings]

FIG. 1 is a sectional 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 the creep occurrence portion of the above.

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

FIG. 6 is a sectional view showing an operating state of the above clutch.

FIG. 7 is a cross-sectional view showing another embodiment.

FIG. 8 is a vertical sectional front view showing a conventional example.

FIG. 9 is a vertical sectional side view of the above.

[Explanation of symbols]

 1 Inner ring 2 Outer ring 5 Cylindrical surface 7 Leaf spring 8 Leaf spring 9 Cam surface 10 Recesses 11, 12 Inclined surface 13 Roller 14 Retainer 16 Ring member 19 Ring part 8a, 8b Spring plate a Minimum clearance

Claims (2)

[Claims] 1. A cylindrical surface is formed on one of opposing surfaces of a bearing ring fitted inside and outside, and a plurality of cam surfaces inclined in the circumferential direction with respect to the cylindrical surface is formed on the other side, and between the two bearing rings. The cage provided is assembled with an engaging element that engages with the narrow portion of the cylindrical surface and the cam surface, and the surface of each cam surface is formed of an elastic material.
In a torque limiter with an automatic return function, in which a deceleration means for decelerating the rotation of a drive-side bearing ring and transmitting it to the cage is connected to the cage, the engaging member is fitted to the surface of the elastic material of each cam surface. A torque limiter with an automatic return function, characterized in that a recessed portion is provided, and a narrow portion where an engaging element engages with a cylindrical surface is formed on both sides of the recessed portion. 2. The torque limiter with an automatic return function according to claim 1, wherein the inner surface of the recess is provided with inclined surfaces which are inclined in directions opposite to each other with respect to the circumferential direction.