JPH0614566U - Torque limiter with automatic return function - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] The present invention is a torque limiter with an automatic return function for transmitting torque by engaging an engaging element between a cam surface and a cylindrical surface provided between raceways. , It is possible to easily change the amount of torque that can be transmitted. A cam plate 7 and a disc spring 8 that pressurizes the cam plate 7 are attached to a spring seat 6 provided on the inner diameter surface of the outer ring 2.
9 is incorporated, and a cam surface 11 forming a wedge-shaped space with the cylindrical surface 5 of the inner ring 1 is formed on the surface of the cam plate 7.
A roller 13 as an engaging element is incorporated in a cage 14 provided between the inner and outer rings 1 and 2, and an annular member 1 connected to the cage 14 by a cylindrical roller 22 press-fitted between the inner ring 1 and the cage 14.
6 is brought into contact with the annular portion 19 associated with the outer ring 2, and the rolling motion of the annular portions 19 causes creep which causes the cage 14 to rotate at a low speed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a torque limiter having a function of automatically returning.

[0002]

[Prior art]

 In propeller propulsion systems of small ships and compressor circuits of refrigeration compressors, etc., when the driven side recovers to the normal state by disconnecting the power transmission on the driven side against overload on the driven side, it returns to the original state. A torque limiter that 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, as a torque limiter that automatically returns at such a long interval, there is a torque limiter previously proposed by the applicant in Japanese Patent Application No. 4-111281.

In this proposal, as shown in FIGS. 7 and 8, a cylindrical surface 5 and a cam surface 11 composed of a polygonal leaf spring 30 are formed on the opposing surfaces of the inner ring 1 and the outer ring 2, In the pocket 15 of the cage 14 provided between the inner and outer rings 1 and 2, the roller 13 that engages with the smallest clearance of the cylindrical surface 5 and the cam surface 11 is incorporated.

Further, the retainer 14 and the outer ring 2 are provided with annular portions 31 and 32 to be fitted with a clearance respectively, the rolling element 33 is incorporated between the inner ring 1 and the retainer 14, and the rolling element 33 is press-fitted to hold it. The container 14 is rolled and guided, and the annular portion 31 is deformed in the radial direction so that the annular portions 31 and 32 are brought into contact with each other at a plurality of positions.

In the above structure, when the leaf spring 30 forming the cam surface 11 is deformed and the roller 13 passes through the engagement position, the cage 14 is rotated by the inner ring 1 via the rolling element 33 to cause the outer ring to rotate. The second circular ring portion 32 rolls to cause creep, and the roller 13 is moved to the next engagement position at a low speed.

[0008]

[Problems to be solved by the device]

 In the proposed torque limiter, the torque is transmitted by the engagement between the roller 13 and the deformable leaf spring 30, so that the magnitude of the torque that can be transmitted is determined by the strength of the elastic force of the leaf spring 30. Therefore, in order to increase the torque transmitted without changing the outer diameter of the limiter, it is necessary to increase the thickness of the leaf spring 30 to increase the elastic force. However, if the spring thickness is increased in this way, deformation will occur. As a result, the bending stress generated inside becomes large, and the life of the leaf spring 30 is shortened.

Further, when the thickness of the leaf spring 30 is increased, the bending stress is increased, and therefore, when the engagement between the roller 13 and the leaf spring 30 is repeated, bending stress due to deformation is repeatedly generated inside the spring. There is also a problem that the leaf spring 5 is easily fatigued by doing so.

Therefore, the present invention aims to provide a torque limiter with an automatic return function that can easily change the torque transmission force without causing a decrease in the life of a spring or the like.

[0011]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention has a structure in which each cam surface is formed of a plate material facing the engaging element and a deformable pressing member for pressing the plate material toward the engaging element. I did.

[0012]

[Action]

 In the above structure, when the pressing force of the pressure member that acts on the plate material is changed, the pressing force that acts on the engaging element when engaging with the cam surface changes, and the amount of torque that can be transmitted is changed. You can

[0013]

【Example】

 1 to 3 show a torque limiter of the embodiment. As shown in FIGS. 1 and 2, one end of the inner ring 1 and the outer ring 2 are 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. It is held coaxially by the guide of No. 4.

The center portion of the outer diameter surface of the inner ring 1 is formed by a cylindrical surface 5 coaxial with the inner and outer rings. On the other hand, on the inner diameter surface of the outer ring 2, eight spring seats 6 are formed at equal intervals in the circumferential direction, and a cam plate 7 and two disc springs 8 and 9 are incorporated in each spring seat 6. ing .

The cam plate 7 is movably fitted inside the spring seat 6, and the elastic force of the disc springs 8 and 9 incorporated on the back surface of the cam plate 7 always applies a pressing force in the direction toward the center of the inner ring 1. Has been. Further, a stopper 10 that engages with the cam plate 7 is provided at the opening of the spring seat 6 to prevent the cam plate 7 from coming out of the spring seat 6. Further, on the side of the disc springs 8 and 9, a retaining piece 24 is attached to prevent the cam plate 7 and the disc springs 8 and 9 from moving in the axial direction.

The inner surface of each cam plate 7 is arranged so as to face the center of the inner ring 1, and the inner surface forms a cam surface 11 that forms a wedge-shaped space with the cylindrical surface 5. Further, a recess 12 into which a roller 13 described later is fitted is formed in the center of the inner surface of each cam plate 7, and the cam surface 11 and the cylinder are inserted between both sides of the recess 12 and the cylindrical surface 5. The minimum clearances a, a between the surfaces 5 are formed. The size of the minimum clearance a is set to be smaller than the diameter d of the roller 13.

An annular cage 14 is provided between the inner ring 1 and the outer ring 2, and a large number of pockets 15 are provided on the circumferential surface of the cage 14 at equal intervals in correspondence with the cam surface 11. Each of the pockets 15 has a roller 13 as an engaging element incorporated therein.

The outer diameter dimension d of the roller 13 is formed to be smaller than the minimum clearance a between the cam surface 11 and the cylindrical surface 5, and only when the clearance is close to the minimum clearance a. It is adapted to engage with the cylindrical surface 5.

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

Further, an engaging member 18 having an L-shaped cross section is integrally press-fitted into the tip portion of the outer ring 2, and the engaging member 18 is fitted into the annular member 16 into an annular ring. The part 19 is formed.

The annular member 16 and the annular portion 19 are fitted with each other through a slight gap δ, and the fitted gap δ is defined by the inner diameter of the annular member 16 and the outer diameter of the annular portion 19. Nominal size of dimension It is set to a value less than a few hundredths of the dimension D.

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. 1 and 3. The cylindrical roller bearing 20 comprises 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 cage 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, and each cylindrical roller 22 is assembled between the annular member 16 and the inner ring in a press-fitted state. By the press-fitting of the cylindrical roller, the annular member 16 is deformed with the cylindrical roller 22 as the apex, and the annular member 16 makes point or line contact with the annular portion 19 of the outer ring 2 at the deformed portion. It is like this.

The torque limiter of this embodiment has the above-mentioned structure, and its operation will be described below. The inner ring 1 is connected to the prime mover side, the outer ring 2 is connected to the driven side, and the outer ring 2 is fixed with the rollers 13 fitted in the recesses 12 of the cam plate 7, as shown in FIGS. 2 and 5. Then, when the inner ring 1 is rotated, the roller 13 is engaged between the recess 12 and the cylindrical surface 5 to form a clutch, and the outer ring 2 rotates integrally with the inner ring 1.

When the torque applied to the outer ring 2 increases from the engaged state of the clutch, the cam plate 7 bends toward the inner side of the spring seat 6 and the torque that can be applied increases. Then, when the overload is continued, the roller 13 passes through the minimum clearance portion a and is discharged to the outside of the recess 12 acting as the clutch, and the clutch function is lost.

At this time, the magnitude of the torque that can be transmitted by the engagement of the roller 13 is determined by the force of the roller 13 pushing back the cam plate 7 to the outer diameter side, that is, the force of elastically deforming the disc springs 8 and 9. It Therefore, when the thickness of the disc springs 8 and 9 or the number of disc springs is changed to change the elastic force acting on the cam plate 7 from the disc springs, the amount of torque that can be transmitted can be arbitrarily changed. You can

In this case, since the spring force of the disc spring can be proportionally changed by changing the number of sheets and the plate thickness, it is possible to accurately set the transmission torque. Further, as a combination method of the disc springs 8 and 9, in addition to the front face butting method as shown in FIG. 2, the disc springs 8 and 9 may be back to each other as shown in FIG. It is also possible to mount the three disc springs 8, 9a, 9b in a combination of the front and the back as shown in FIG.

On the other hand, when the roller 13 is released from the recess 12 and the motor side continues to rotate with the torque transmission being released, and the inner ring 1 and the outer ring 2 rotate relative to each other, the rotational load of the inner ring 1 becomes a cylindrical roller 22. Is transmitted to the annular member 16 via. Therefore, the annular member 16 makes an inscribed rolling motion around the outer diameter of the annular portion 19 of the outer ring 2 to cause creep. That is, when the cylindrical roller 22 makes one round inside the annular member 16, the annular member 16 and the annular portion 19 rotate relative to each other 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 speed lower than the rotation of the inner ring 1, and the roller 13 is rotated by a small distance per rotation. Move it. Therefore, 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 return with a sufficient time margin can be repeated.

In the above embodiments, the disc spring is used as the means for pressurizing the cam plate 7, but instead of the disc spring, another spring material such as a coil spring or a leaf spring, or a rubber is used. Etc. can also be used. Further, instead of the elastic member, a working fluid such as pressure oil or high-pressure air may be enclosed in the back surface of the cam plate 7, and the cam plate 7 may be pressed by the fluid pressure.

Further, in the above embodiment, the inner ring 1 is on the driving side and the outer ring 2 is on the driven side. Conversely, even 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.

[0031]

【effect】

 As described above, in the present invention, the cam surface is formed of the plate material and the pressing member, so that the force acting on the engaging element at the time of engagement with the cam surface can be arbitrarily changed, and the torque that can be transmitted can be changed. The effect is that it can be changed easily.

[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.

6A and 6B are cross-sectional views showing a method of combining disc springs, respectively.

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

FIG. 8 is a vertical side view of the above.

[Explanation of symbols]

 1 Inner ring 2 Outer ring 5 Cylindrical surface 6 Spring seat 7 Cam plate 8, 9 Disc spring 11 Cam surface 13 Roller 14 Cage 16 Ring member 19 Ring part 22 Cylindrical roller a Minimum clearance

Claims (1)

[Scope of utility model registration request] 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. In the provided cage, an engaging element that engages with the narrow portion of the cylindrical surface and the cam surface is incorporated to elastically deform each of the cam surfaces, and the cage is configured to rotate the drive-side bearing ring. In a torque limiter with an automatic return function, which is connected to a decelerating means for decelerating and transmitting to a retainer, each cam surface is provided with a plate member facing the engaging member and a deformable member for pressing the plate member toward the engaging member. A torque limiter with an automatic return function characterized by being formed from a pressure member.