JPH0612835U - Torque limiter - Google Patents

Abstract

(57) [Abstract] [Purpose] To increase the torque capacity and prevent the set torque from decreasing in the torque limiter. [Structure] Friction plates 13 and 14 guided by splines 11b and 12b are provided between a shaft member 11 and a cylindrical member 12, and each friction plate 13 and 14 is guided by a piston 17 via a fall member 19 in an upright posture. After being pressed and brought into pressure contact, the hydraulic piston 17 is locked by the lock member 18. And
When the positions of the shaft member 11 and the tubular member 12 around the axes change during use, the overturning member 19 falls over and the friction plates 13,
A gap is formed between the fourteen.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a torque limiter capable of increasing torque capacity.

[0002]

[Prior art]

 Conventionally, as a torque limiter, as shown in FIG. 5, an inner peripheral surface of a cylindrical member 2 is fitted on an outer peripheral surface of a shaft member 1, and pressure oil is supplied to a hydraulic passage 2a of the cylindrical member 2 to supply a shear tube. On the other hand, there is a shaft member 1 that is sealed with a locking member 4 that locks an end of the shear tube 3 (see Japanese Patent Publication No. 63-30527).

The pressure oil in the hydraulic passage 2 a reduces the diameter of the inner peripheral surface of the tubular member 2 and presses it against the outer peripheral surface of the shaft member 1. As a result, the shaft member 1 and the tubular member 2 are frictionally coupled and torque is transmitted. When the shaft member 1 and the tubular member 2 are loaded with a load equal to or more than a predetermined value and the inner peripheral surface of the tubular member 2 slips, and the positions of the shaft member 1 and the tubular member 2 around the axes change, the locking is performed. The end of the shear tube 3 is cut by the member 4, and the pressure oil in the hydraulic passage 2a is discharged to the outside. As a result, the frictional coupling between the shaft member 1 and the tubular member 2 is released and torque is no longer transmitted.

[0004]

[Problems to be solved by the device]

 However, the conventional torque limiter has a problem that the torque capacity per a predetermined size is relatively small because the area of the friction surface is limited by the shaft diameter and the shaft length. Also, since it is necessary to always apply hydraulic pressure, there is a problem that the set torque is likely to decrease due to hydraulic pressure leakage.

Therefore, an object of the present invention is to provide a torque limiter which has a large torque capacity per predetermined size and which does not cause a decrease in set torque.

[0006]

In order to achieve the above object, the present invention provides a shaft member having a spline on an outer peripheral surface, a tubular member having a spline on an inner peripheral surface, and a spline of the shaft member in the axial direction. A plurality of shaft-side friction plates that are movably guided and cannot rotate and a shaft member that is movably guided in the axial direction by the spline of the tubular member, and are non-rotatably provided alternately between the shaft-side friction plates. A cylinder side friction plate, a hydraulic piston for axially pressing the shaft side friction plate and the cylinder side friction plate into pressure contact, a lock member for locking the hydraulic piston at a predetermined pressing position, and the shaft side friction plate The longitudinal direction is set in the axial direction between the cylinder side friction plate, or between the part rotating with the shaft member and the cylinder side friction plate, or between the part rotating with the cylinder member and the shaft side friction plate. The shaft is installed in a standing posture A fall member that falls so that the longitudinal direction is in the circumferential direction when the axial positions of the material and the tubular member change, and a holding member that holds the fall member and biases the fall member to the standing position. It is characterized by having a vessel.

[0007]

[Action]

 According to the torque limiter of the present invention, the overturning member is set in an upright posture in which the longitudinal direction is in the axial direction, and the friction pistons are pressed by the hydraulic pistons to make pressure contact, and then the hydraulic pistons are locked by the locking members. Lock it. When the shaft member or the tubular member is loaded with a load of a predetermined value or more during use and the positions of the shaft member and the tubular member around the axis change, the tipping member falls and the longitudinal direction is directed in the circumferential direction. Since the pressing force on the adjacent friction plates is released, a gap is created between the friction plates, the frictional coupling between the shaft member and the tubular member is released, and torque is not transmitted.

[0008]

【Example】

 Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. As shown in FIG. 1, the torque limiter of this embodiment includes a shaft member 11 and a tubular member 12. The shaft member 11 has a flange portion 11a, and a spline 11b is formed on the outer peripheral surface of the shaft member 11. The tubular member 12 has a flange portion 12a, and a spline 12b is formed on the inner peripheral surface of the tubular member 12.

A plurality of shaft-side friction plates 13 are formed on the outer periphery that is slightly smaller than the inner peripheral surface of the cylindrical member 12, and have on the inner periphery a spline 13 a that fits into a spline 11 b formed on the shaft member 11. , 13 are arranged between the cylindrical member 12 and the shaft member 11. The shaft side friction plates 13, ..., 13 are guided by the splines 11b of the shaft member 11 so as to be movable in the axial direction.

A plurality of cylinder-side friction plates 14, ..., Which have an inner diameter slightly larger than the outer diameter of the shaft member 11 and a spline 14a fitted on the spline 12b of the cylinder member 12 on the outer peripheral side. 14 is arranged between the tubular member 12 and the shaft member 11. The cylinder side friction plates 14, ..., 14 are alternately interposed between the shaft side friction plates 13, ..., 13 and are guided by the splines 12b so as to be movable in the axial direction. .

A sleeve 16 that forms a hydraulic chamber 15 with the outer peripheral surface of the shaft member 11 is integrally fitted on the flange 11 a side of the shaft member 11, and the sleeve 16 has the above-mentioned hydraulic pressure. An oil pressure inlet 16a leading to the chamber 15 is provided.

A piston 17 is fitted in the hydraulic chamber 15 so as to be movable in the axial direction, and a tip portion of the piston 17 comes into contact with an axial friction plate 13 closest to the piston 17. When the piston 17 moves to the right in the figure, the piston 17 presses the shaft-side friction plates 13 and the cylinder-side friction plates 14 to the right and presses them.

A male screw 17a is formed on the outer peripheral surface of the piston 17 on the front side, and a female screw 18a of a lock member 18 is screwed to the male screw 17a. When the piston 17 is hydraulically moved to a predetermined pressing position, the lock member 18 is screw-operated to bring the rear end face 18b into contact with the front end face 16b of the sleeve 16, thereby allowing the piston 17 to move. Can be locked in the pressed position.

As shown in detail in FIGS. 2 and 3, a circular arc-shaped outer peripheral surface is provided in the space S between the axial side friction plate 13 and the cylinder side friction plate 14 which are closest to and adjacent to the piston 17. A plurality of so-called sprag-shaped overturning members 19 having wide portions 19a, 19a on both sides in the longitudinal direction and a narrow portion 19b constricted inward in the longitudinal direction are arranged at equal intervals on the circumference. ing.

At the time of setting, each of the overturning members 19 causes the outer peripheral surfaces of the wide width portions 19a, 19a to come into contact with the facing surfaces 13a, 14a of the friction plates 13, 14 as shown in FIG. The space S is held by interposing 19a in an upright posture in the axial direction.

The tumbling members 19 are held by a cage 20 at equal intervals on the circumference. Then, the spring claws 20a, 20a of the retainer 20 are fitted into the narrow width portion 19b to urge each of the falling members 19 in the standing posture.

According to the above configuration, at the time of setting, after the wide portion 19a of the overturning member 19 is set to the standing position, the pressure oil is supplied from the hydraulic pressure inlet 16a of the sleeve 16 to the hydraulic chamber 15. Then, the piston 17 moves to the right, presses the shaft side friction plate 13 and the cylinder side friction plate 14 into pressure contact, and frictionally couples the shaft member 11 and the cylinder member 12. Then, when the piston 17 is moved to a predetermined position and the initial setting of the torque by pressing the friction plates 13 and 14 is completed, the lock member 18 is screwed to lock the piston 17 at the pressing position, Stop supplying pressure oil. The tipping member 19 provided between the friction plates 13 and 14 is pushed by the piston 17 and is stretched against the friction plates 13 and 14 to hold the space S.

When the use is started in this state and the shaft member 11 and the tubular member 12 are subjected to a load of a predetermined value or more during use and the positions of the shaft member 11 and the tubular member 12 around the axes change, The positions of the friction plates 13 and 14 around the axis also change. Then, as shown in FIG. 4, the tipping member 19 that is stretched between the friction plates 13 and 14 changes the position of the friction plates 13 and 14 around the axis thereof, and thus the spring claw 20a of the retainer 20. Against the urging force of 20a, it falls down with the narrow portion at the center in the longitudinal direction as the center and the longitudinal direction facing the circumferential direction. As a result, the tipping member 19 ceases to be stretched between the friction plates 13 and 14, so that the friction plates 13 and 14 come close to each other and the space S becomes narrow, so that the space between the friction plates 13 and 14 is reduced. A gap is generated, the frictional connection between the shaft member 11 and the tubular member 12 is released, and torque is not transmitted between the shaft member 11 and the tubular member 12.

On the other hand, at the time of resetting, when the lock member 18 is screw-operated to move the piston 17 to the left and, as shown in FIG. 3, the space between the friction plates 13 and 14 is expanded to the space S, The overturning member 19 is automatically returned to the standing posture by the urging force of the spring claws 20a, 20a of the retainer 20. After that, in the same manner as described above, the piston 17 may be hydraulically moved to lock the piston 17 with the lock member 18.

Since the shaft member 11 and the tubular member 12 are frictionally coupled by the plurality of friction plates 13 and 14, the area of the friction surface can be made larger than that of the conventional example, and the torque transmission for a predetermined size can be achieved. You can improve your ability. Further, since the initial setting of the torque is performed not by the lock member 18 but by the piston 17 by the hydraulic pressure of the hydraulic chamber 15, the torque setting is easy. Furthermore, since the piston 17 is locked by the lock member 18 after the torque is set, hydraulic pressure is not required, and variations in torque transmission capability due to oil leakage do not occur. The overturning member may be provided between the portion that rotates together with the shaft member and the cylinder side friction plate, or between the portion that rotates together with the cylinder member and the shaft side friction plate.

[0021]

[Effect of device]

 As is clear from the above description, the torque limiter of the present invention presses the friction plate by the pressing operation of the hydraulic piston to bring it into pressure contact, then locks the hydraulic piston with the lock member, and causes the friction by the upright overturning member. While the pressing force is generated between the plates, when the position around the axis of the shaft member and the cylinder member changes during use, the above-mentioned overturning member falls and the pressing force between the friction plates is released, and between the friction plates. A gap is created and the frictional connection between the shaft member and the cylinder member is released to prevent torque from being transmitted.

Therefore, according to the present invention, since the shaft member and the tubular member are frictionally coupled by the plurality of friction plates, the area of the friction surface of the friction coupling can be made larger than that of the conventional example, and the predetermined size can be achieved. The torque transmission capacity per hit can be improved, making it easy to manufacture a torque limiter with a high torque capacity. Moreover, since the initial setting of torque is performed by the hydraulic piston, torque setting is easy. Furthermore, after the torque is set, the hydraulic piston is locked by the lock member, so hydraulic pressure is not required, and variations in torque transmission capacity due to oil leakage do not occur, and torque transmission capacity equivalent to that at initial setting is achieved. Can be maintained for a long time.

[Brief description of drawings]

FIG. 1 is a side sectional view of a torque limiter of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a plan view of the falling member in the standing position.

FIG. 4 is a plan view of the falling member in the falling position.

FIG. 5 is a sectional view of a conventional torque limiter.

[Explanation of symbols]

11 ... Shaft member, 11b ... Spline, 12 ... Cylindrical member, 1
2b ... Splines, 13, 14 ... Friction plates, 15 ... Hydraulic chambers, 17 ... Hydraulic pistons, 18 ... Lock members, 19 ... Falling members, 19a ... Wide parts, 19b ... Narrow parts, S ... Spaces.

Claims (1)

[Scope of utility model registration request] 1. A shaft member having an outer peripheral surface with a spline, a cylindrical member having an inner peripheral surface with a spline, and a plurality of non-rotatable shaft side frictions which are axially movably guided by the spline of the shaft member. A non-rotatable cylinder-side friction plate, which is guided by a spline of the cylinder member so as to be movable in the axial direction and is alternately interposed between the shaft-side friction plates, and the shaft-side friction plate and the cylinder-side friction plate. A hydraulic piston that axially presses and presses the lock, a lock member that locks the hydraulic piston at a predetermined pressing position, a portion between the shaft side friction plate and the cylinder side friction plate, or a portion that rotates together with the shaft member. Between the shaft-side friction plate and the shaft-side friction plate, or between the shaft member and the shaft-side friction plate that rotate together with the shaft-shaped member. When the position of changes, A torque limiter comprising: a falling member that falls down in a circumferential direction; and a retainer that holds the falling member and biases the falling member to an upright position.