JPH0547551U - Torque limiter - Google Patents

Abstract

(57) [Summary] [Purpose] In a torque limiter, increase the torque transmission capacity and eliminate variations and decreases in the torque transmission capacity. [Structure] A plurality of friction plates 13 and 14 are provided between a shaft member 11 and a tubular member 12, and a piston 17 of a hydraulic chamber 15 presses each friction plate 13 and 14 through a pressing spring 18 to bring them into pressure contact. At the same time, after locking the piston 17 at a predetermined position with the lock member 20, the pressure oil in the hydraulic chamber 15 is drained. The shaft member 11 and the tubular member 12 are frictionally coupled by a plurality of friction plates 13 and 14. The torque is initially set by hydraulic pressure, and after the torque is set, the pressure oil is drained to lock the piston 17 with the lock member 20.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of a torque limiter.

[0002]

[Prior Art]

 Conventionally, as a torque limiter, as shown in FIG. 6, 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 provide a shear tube. On the other hand, the shaft member 1 may be sealed with a locking member 4 that locks the 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 cylindrical member 2 and presses 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 above-mentioned conventional torque limiter has a problem that the torque transmission capability is low because the area of the friction surface is limited. In addition, since it is a type that constantly applies hydraulic pressure, if oil leaks from the filler port after refueling, the internal pressure will change and the torque transmission capacity will vary, and if oil leaks from the fitting part of the valve etc. during use. There was a problem that the internal pressure changed and the torque transmission capacity decreased.

Therefore, an object of the present invention is to provide a torque limiter which has a high torque transmission capacity and which does not fluctuate or decrease in torque transmission capacity.

[0006]

[Means for Solving the Problems]

 To achieve the above object, the present invention provides a shaft member having an axial spline on an outer peripheral surface, a tubular member having an axial spline and a locking serration on an inner peripheral surface, and a spline of the shaft member. A plurality of shaft-side friction plates that are movably guided in the axial direction, and a cylinder-side friction plate that is movably guided in the axial direction by the spline of the cylindrical member and that is alternately interposed between the shaft-side friction plates. A piston that presses the shaft-side friction plate and the cylinder-side friction plate in the axial direction for pressure contact, a pressing spring that is interposed between the piston and the friction plate closest to the piston, and the piston Is slidably fitted to the hydraulic chamber and is locked axially by the locking serrations provided on the tubular member, and unlocks the locking serrations on the tubular member when it is rotated for a certain period. Has a locking selection that is It is characterized in that a lock member for locking in place a pressing actuated piston pressure oil of the hydraulic chamber.

[0007]

[Action]

 According to the torque limiter of the present invention, pressure oil is supplied to the hydraulic chamber to cause the piston to slide in the direction of the friction plate, and the piston causes the friction plates to be pressed and pressed against each other via the pressing springs. After locking the piston in place with the lock member, drain the pressure oil from the hydraulic chamber. 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 locking serration of the locking member causes the locking serration of the locking member. Is unlocked. As a result, the lock member can escape in the axial direction, the piston moves in the counter-pressing direction by the pressure spring, and the pressure contact between the friction plates is released, and the frictional coupling between the shaft member and the tubular member is released. As a result, torque is no longer transmitted.

As described above, since the shaft member and the tubular member are frictionally coupled to each other by the plurality of friction plates, the area of the friction surface is increased and the torque transmission capability is increased. Therefore, it becomes easy to manufacture a torque limiter having a high torque capacity. Also, since the initial setting of torque is hydraulic, it is easy to set the torque, and after the torque is set, the pressure oil is drained and the piston is locked by the lock member, which may cause variations in torque transmission capacity due to oil leakage. No decrease occurs. Therefore, the torque transmission capacity equivalent to that at the time of initial setting can be maintained for a long period of time.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. As shown in FIG. 1, a shaft member 11 and a tubular member 12 are provided. This shaft member 11 is provided with a flange portion 11a, an axial convex spline 11b (see FIG. 3) is formed on the outer peripheral surface of the tip portion of the shaft member 11, and a tapered surface 11c is formed on the base portion of the shaft member 11. Are formed. The tubular member 12 is provided with a flange portion 12a, and a concave spline 12b (see FIG. 4) of the tubular member is formed on the inner peripheral surface of the base portion of the tubular member 12.

As shown in FIG. 3, a plurality of recesses 14 a are formed on the outer periphery that is slightly smaller than the inner peripheral surface of the tubular member 12, and have a recess 14 a on the inner periphery that fits into the convex spline 11 b of the shaft member 11. , 14 are provided, and the shaft side friction plates 14, ..., 14 are guided by the convex splines 11b so as to be movable in the axial direction.

As shown in FIG. 4, a plurality of protrusions 13 a are formed on the inner periphery that is slightly larger than the outer peripheral surface of the shaft member 11 and on the outer periphery have convex portions 13 a that fit into the concave splines 12 b of the cylindrical member 12. , 13 are provided on the cylinder side, and the cylinder side friction plates 13, ..., 13 are provided alternately with the shaft side friction plates 14 ,. The concave spline 12b is guided so as to be movable in the axial direction.

As shown in FIG. 1 and FIG. 2, a sleeve 16 that forms a hydraulic chamber 15 between the inner peripheral surface of the tubular member 12 and the tip portion of the tubular member 12 is integrally fitted, A flange portion 16a of the sleeve 16 is provided with an oil supply port 16b communicating with the hydraulic chamber 15. An internal thread 16c is formed on the inner peripheral surface of the sleeve 16.

A piston 17 is movably fitted in the hydraulic chamber 15 in the axial direction, and a plunger 19 is fitted to the tip of the piston 17 via a plurality of disc springs 18, 18. .. When pressure oil is supplied to the hydraulic chamber 15, the piston 17 moves to the right in the figure, and the plunger 19 moves to the right via the disc springs 18 and 18. The shaft side friction plate 14 and the cylinder side friction plate 13 are pressed to the right and brought into pressure contact with each other.

On the other hand, as shown in FIG. 2, the inner peripheral surface is axially movably fitted to the base of the shaft member 11 via the bush 23, and the female screw 16c of the sleeve 16 is fitted to the outer peripheral surface. A sleeve-shaped lock member 20 having a male screw 20a to be screwed is provided.

As shown in FIG. 5, an outer peripheral surface of the lock member 20 is formed with an axial engagement serration 20 b at a depth reaching the bottom of the male screw 20 a, and an inner peripheral surface of the sleeve 16 is formed. An axial locking serration 16d is formed at a depth reaching the bottom of the female screw 16c. Then, when the male thread 16c of the sleeve 16 is screwed into the male thread 20a of the lock member 20, the locking member 20 is axially moved at a rotational position where the locking serration 16d of the sleeve 16 overlaps with the locking serration 20b of the locking member 20. It is locked. Therefore, the movement of the lock member 20 to the left in FIG. 1 is locked. On the other hand, at the rotational position where the locking serration 16d of the sleeve 16 does not overlap the locking selection 20b of the lock member 20, the locking of the lock member 20 is released.

As shown in FIG. 2, the lock member 20 locks the piston 17 at a predetermined position at its tip, and the rear end of the lock member 20 corresponds to the taper surface 11 c of the shaft member 11. Set screw 21 is set.

According to the above configuration, when pressure oil is supplied from the oil supply port 16b of the sleeve 16 to the hydraulic chamber 15, the piston 19 moves rightward by the piston 17 via the disc springs 18 and 18 to cause the axial friction. The shaft member 11 and the tubular member 12 are frictionally coupled by pressing the plate 14 and the tubular friction plate 13 into pressure contact with each other.

When the piston 17 is moved to a predetermined position and the initial setting of the torque by the pressure contact between the friction plates 13 and 14 is completed, the male screw 20a of the lock member 20 is screwed into the female screw 16c of the sleeve 16, The front end of the lock member 20 is brought into contact with the rear end of the piston 17. The rotation position of the lock member 20 is adjusted at this contact position, and the locking serration 20b of the lock member 20 is superposed on the locking serration 16d of the sleeve 16. As a result, the lock member 20 is locked so as not to move to the left in FIGS. 1 and 2, and the piston 17 is locked at a predetermined position. When the set screw 21 of the lock member 20 is screwed into contact with the tapered surface 11c of the shaft member 11 at this position, the rotation of the lock member 20 is restricted. Since the set screw 21 is only brought into contact with the tapered surface 11c, when the engagement between the locking serration 16d and the locking serration 20b is released, the lock member 20 is moved to the left in the axial direction in FIG. It becomes possible to move in the direction.

After that, the pressure oil in the hydraulic chamber 15 is drained from the oil supply port 16b of the sleeve 16. At this time, the piston 17 does not move to the left because it is locked at a predetermined position by the lock member 20.

When the shaft member 11 and the tubular member 12 are used in this state and a load of a predetermined value or more is applied during use, and the positions of the shaft member 11 and the tubular member 12 around the axes change, the tubular member The locking serration 16b of the sleeve 16 integrated with the locking member 12 unlocks the locking serration 20b of the lock member 20.

As a result, the lock member 20 moves together with the piston 17 to the left in FIG. 1 by the urging force of the disc springs 18, 18, so that the piston 17 stops pressing the friction plates 13, 14 and the shaft members The frictional connection between 11 and the tubular member 12 is released, and torque is no longer transmitted.

In the above structure, the shaft member 11 and the tubular member 12 are frictionally coupled by the plurality of friction plates 13 and 14, so that the area of the friction surface is large and the torque transmission capability is high. Further, since the initial setting of the torque is performed not by the lock member 20 but by the piston 17 by the hydraulic pressure of the hydraulic chamber 15, the torque setting is easy. Further, since the piston 17 is locked by the lock member 20 after the torque is set, hydraulic pressure is not required, and variations in torque transmission capability due to oil leakage do not occur.

[0023]

[Effect of the device]

 As is clear from the above description, in the torque limiter of 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 is large. Therefore, it is easy to manufacture a torque limiter with high torque transmission capacity and high torque capacity. Moreover, since the initial setting of the torque is performed by hydraulic pressure, it is easy to set the torque. However, after setting the torque, the pressure oil is drained and the piston is locked by the lock member, so there is no variation or decrease in torque transmission capacity due to oil leakage, and torque transmission capacity equivalent to that at initial setting is maintained for a long time. Can be maintained.

[Brief description of drawings]

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

2 is a partially enlarged view of FIG.

FIG. 3 is a sectional view taken along line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is an enlarged view of a main part of line CC in FIG.

FIG. 6 is a sectional view of a conventional torque limiter.

[Explanation of symbols]

11 ... Shaft member, 11b ... Convex spline, 12 ... Cylindrical member,
12b ... Concave spline, 13,14 ... Friction plate, 15 ... Hydraulic chamber, 16 ... Sleeve, 16d ... Locking serration, 17
... Piston, 18 ... Disc spring, 20 ... Lock member, 20b
… Locking serrations.

Claims (1)

[Scope of utility model registration request] 1. A shaft member having an axial spline on an outer peripheral surface, a tubular member having an axial spline and a locking serration on an inner peripheral surface, and a guide movably in the axial direction by the spline of the shaft member. A plurality of shaft-side friction plates, a tube-side friction plate that is axially movably guided by a spline of the cylinder member, and is alternately interposed between the shaft-side friction plates, and the shaft-side friction plate. A piston that presses the cylinder-side friction plate in the axial direction for pressure contact, a pressing spring that is interposed between the piston and the friction plate that is closest to the piston, and the piston is slidably fitted. And a locking serration that is axially locked to the locking serration provided on the tubular member and that is unlocked from the locking serration of the tubular member when rotated a predetermined time,
A torque limiter, comprising: a lock member that locks a piston, which is pressed by the pressure oil in the hydraulic chamber, at a predetermined position.