JPH0573322U - 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 cylindrical member 12, and each friction plate 13 and 14 is pressed into pressure contact with a piston 22 of a hydraulic chamber 15 via a ball 24. , The piston 22 is locked in place by the locking member 26. When the positions of the shaft member 11 and the tubular member 12 are changed during use, the balls 24 allow the balls to escape.
The friction plates 13 and 14 are engaged with each other to release the pressure contact between the friction plates 13 and 14, and the frictional coupling between the shaft member 11 and the cylindrical member 12 is released.

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. 11, 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 the shear tube 3 with the pressure oil. On the other hand, there is a shaft member 1 which is fixed by a locking member 4 for locking the end portion 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.

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 uses 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 such as the valve during use, the internal pressure will change. However, there was a problem that the torque transmission capacity was reduced due to the change of the torque.

[0005]

[Problems to be solved by the device]

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

[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 on an inner peripheral surface, and an axial member that moves axially by a spline of the shaft member. A plurality of shaft-side friction plates that are freely guided, a cylinder-side friction plate that is guided by the 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. Between the piston and the friction plate that is closest to the piston, and is arranged so as to be able to roll at a predetermined pitch on the circumference. A rolling element held by a cage, at least one of an interposing surface of the piston on which the rolling element is interposed, and an interposing surface of the friction plate, which are formed at the same pitch as the rolling element. Rolling element relief concave that allows rolling elements to escape axially When, is characterized in that the piston is provided with a hydraulic chamber which is slidably fitted, and a lock member for locking the piston is pressed actuated by pressure oil of the hydraulic chamber at a predetermined position.

[0007]

[Action]

 According to the present invention, after the rolling element is set in the middle of the pitch of the rolling element relief recess, pressure oil is supplied to the hydraulic chamber to slide the piston in the direction of the friction plate, and the piston moves the rolling element through the rolling element. Then, the friction plates are pressed against each other for pressure contact, and the piston is locked at a predetermined position by a lock member, and then the pressure oil in the hydraulic chamber is drained. When the shaft member or the cylinder member is loaded with a load of a predetermined value or more during use and the positions of the shaft member and the cylinder member around the axis change, the rolling elements are installed on the interposition surface of the piston and the friction plate. Roll over the surface and fit into the recess for the rolling element to escape. As a result, the pressure contact between the friction plates by the rolling elements is released, the frictional coupling between the shaft member and the tubular member is released, and torque is not 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. Also, since the initial setting of torque is performed by hydraulic pressure, 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. Does not occur. Therefore, it is possible to maintain the same torque transmission capability as that at the time of initial setting for a long time. Further, since the torque releasing mechanism is a rolling type of rolling element, a difference in releasing torque depending on the forward and reverse directions of torque is unlikely to occur. Further, since the rolling elements are in rolling contact, the friction torque is small and the influence on the opening torque (set torque) is small. Furthermore, since the shaft member and the tubular member are basically connected only by the friction plate, the sliding type in which the shaft member and the tubular member move in the axial direction can be applied.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. The parts having the same configurations and functions as those of the techniques of FIGS. 11 and 12 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, a shaft member 11 and a tubular member 12 are provided. The shaft member 11 is provided with a flange portion 11a, and an axial convex spline 11b (see FIG. 2) is formed on the outer peripheral surface of the tip portion of the shaft member 11. The tubular member 12 is provided with a flange portion 12a, and an axial concave spline 12b (see FIG. 3) is formed on the inner peripheral surface of the base portion of the tubular member 12.

As shown in FIG. 2, a plurality of recesses 14a are formed on the outer periphery that is slightly smaller than the inner peripheral surface of the tubular member 12, and have a recess 14a that fits into the convex spline 11b of the shaft member 11 on the inner periphery. , 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. 3, 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 have on the outer periphery a convex portion 13 a that fits into the concave spline 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, between the tip portion of the tubular member 12 and the base portion of the shaft member 11, the inner peripheral surface is fitted to the outer peripheral surface of the shaft member 11, and the outer peripheral surface is the tubular member 12. A piston 22 which is fitted to the inner peripheral surface of the cylinder member 12 and forms a hydraulic chamber 15 with the inner peripheral surface of the cylindrical member 12 is provided movably in the axial direction. A refueling port 12c leading to the is provided.

A plunger (friction plate) 23 is attached to the tip of the piston 22. When pressure oil is supplied to the hydraulic chamber 15, the piston 22 moves to the right in the figure, and the shaft side friction plate 14 is moved through the plunger 23 and a ball (rolling element) 24 described later. The cylinder side friction plate 13 is pressed to the right and brought into pressure contact. The plunger 23 may be integrated with the piston 22.

A large number of balls 24 are rollably interposed at a predetermined pitch on the circumference between the plunger 23 of the piston 22 and the friction plate 14 closest to the plunger 23. There is. The balls 24 are held at a predetermined pitch by a retainer 25 (see FIG. 4), and the retainer 25 is provided with a handle portion 25a extending outward in the radial direction. The handle portion 25a is fitted into a radial long hole 12e formed in the tubular member 12 so as to be rotatable around an axis with a width of the above pitch, and the front portion is exposed to the outside. A seal and pressure contact member 27 is pressed against the inner wall of the elongated hole 12e.

As shown in detail in FIGS. 4 to 7, the ball-inserted surface of the plunger 23 and the ball-inserted surface of the friction plate 14 are fitted with the ends of the balls 24 to guide them in the circumferential direction. Raceway grooves 23a and 14b are formed respectively for this purpose. .., 23b having a square or V-shape at the same pitch as the pitch of the balls 24 are formed on the ball interposing surface of the plunger 23, and the raceway grooves 23a, 14b of each interposing surface are formed. When the ball 24 is fitted into the ball escape recess 23b, the ball 24 moves (is released) in the axial direction. A roller may be used instead of the ball 24. The ball escape recess 23b may have a circular shape as shown in FIGS. 8 and 9.

As shown in FIG. 1, a lock member 26 fitted to the outer peripheral surface of the base portion of the shaft member 11 is provided, and the outer peripheral surface of the lock member 26 has an inner peripheral surface of the tip portion of the tubular member 12. A male screw 26a is formed on the surface to be screwed with the screw 12d. The lock member 26 locks the piston 22 at a predetermined position at its tip.

According to the above configuration, the ball 24 is set by the retainer 25 in the orbital recesses 23a and 14b in the middle of the pitch of the ball escape groove 23b (the state of FIGS. 4 and 5), and then the tubular member When pressure oil is supplied from the oil supply port 12c of 12 to the hydraulic chamber 15, the piston 22 moves to the right in the drawing, and the shaft side friction plate 14 and the cylinder side friction plate 13 are moved through the plunger 23 and the ball 24. The shaft member 11 and the tubular member 12 are frictionally coupled by pressing and pressing.

When the piston 22 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 26 a of the lock member 26 is screwed into the female screw 12 d of the tubular member 12. The tip of the lock member 26 is brought into contact with the rear end of the piston 22 by advancing. As a result, the piston 22 is locked at a predetermined position by the lock member 26.

After that, the pressure oil in the hydraulic chamber 15 is drained from the oil supply port 12c of the tubular member 12. At this time, the piston 22 does not move to the left because it is locked by the lock member 26 at a predetermined position.

When the shaft member 11 and the tubular member 12 are started to be used in this state and a load larger than a predetermined value is applied to the shaft member 11 and the tubular member 12 during use, the positions of the shaft member 11 and the tubular member 12 around the axes are changed. The roller 24 rolls in the raceway groove 23a on the interposing surface of the plunger 23 and the track recess 14b on the interposing surface of the friction plate 14 and fits into the ball escape recess 23b (states of FIGS. 6 and 7).

As a result, the ball 24 escapes to the left in FIG. 1, so that the ball 24 stops the pressure contact between the friction plates 13 and 14, and the frictional coupling between the shaft member 11 and the tubular member 12 is released, and the torque is reduced. It will not be transmitted.

In order to restore the transmission of the torque, the lock member 26 is moved backward to move the piston 22 leftward in the drawing, and then the handle portion 25a of the retainer 25 is rotated from the outside about the axis. Then, the balls 24 come out of the ball escape recesses 23b. Therefore, if the balls 24 are set in the middle of the pitches of the ball escape recesses 23b, the shaft member 11 and the tubular member 12 can be frictionally joined again by the procedure described above. it can.

In the above structure, 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 is large and the torque transmission capability is high. Further, since the initial setting of the torque is performed not by the lock member 26 but by the piston 22 by the hydraulic pressure of the hydraulic chamber 15, the torque setting is easy. Furthermore, after the torque is set, the piston 22 is locked by the lock member 26, so that hydraulic pressure is not required and variations in torque transmission capability due to oil leakage do not occur.

On the other hand, since the torque is released by the rolling method of the ball 24, a difference in the open torque depending on the forward and reverse directions of the torque is unlikely to occur. Further, since the balls 24 are in rolling contact, the friction torque is small and the influence on the opening torque (set torque) is small.

FIG. 10 shows a second embodiment, in which a sleeve 30 is fitted on the outer peripheral surface of the base portion of the shaft member 11, and the rear end portion of the sleeve 30 is brought into contact with the flange portion 11a. Further, the inner peripheral surface is fitted to the outer peripheral surface of the shaft member 11, the outer peripheral surface is fitted to the inner peripheral surface of the sleeve 30, and a piston 31 that forms a hydraulic chamber 15 between the inner peripheral surface and the inner peripheral surface of the sleeve 30. Is provided movably in the axial direction, and the sleeve 30 is provided with an oil supply hole 30 a communicating with the hydraulic chamber 15. A male screw 31a is formed on the outer peripheral surface of the tip of the piston 31, and a screw 32a is screwed onto the male screw 31a to form the inner peripheral surface of the lock member 32.

With the above configuration, when pressure oil is supplied from the oil supply port 30a of the sleeve 30 to the hydraulic chamber 15, the piston 31 moves to the right in the figure, and the shaft side friction is caused via the plunger 23 and the ball 24. 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 31 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 lock member 32 is screwed backward. As a result, the rear end of the lock member 32 comes into contact with the front end of the sleeve 30 and stretches, and the piston 31 can be locked at a predetermined position by the lock member 32.

[0029]

[Effect of the device]

 As is clear from the above description, the torque limiter of the present invention is used when the shaft member or the tubular member is loaded with a load more than a predetermined value during use and the positions of the shaft member and the tubular member around the axis change. , The rolling element rolls on the interposition surface of the piston and the interposition surface of the friction plate and fits into the rolling element escape groove, and the frictional connection between the shaft member and the tubular member is released by releasing the pressure contact of each friction plate by the rolling element. It is designed so that the torque is not transmitted when it is unwound. As described above, since the shaft member and the tubular member are frictionally coupled by the plurality of friction plates, the area of the friction surface is increased and the torque transmission capability can be increased. Also, since the initial setting of the torque is done hydraulically, it is easy to set the torque. Moreover, after the torque is set, the pressure oil is drained and the piston is locked by the lock member, so there is no variation or reduction in torque transmission capacity due to oil leakage, and torque transmission capacity equivalent to that at initial setting is maintained for a long period of time. Can be maintained over time. Further, since the torque release is a rolling type rolling element, a difference in the release torque depending on the direction of the torque is unlikely to occur. Further, since the rolling elements are in rolling contact, the friction torque is small and the influence on the opening torque (set torque) is small. Further, since the shaft member and the tubular member are basically connected only by the friction plate, the sliding type in which the shaft member and the tubular member move in the axial direction can be applied.

[Brief description of drawings]

FIG. 1 is a side sectional view of a torque limiter according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

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

FIG. 4 is an enlarged view of a main part of FIG. 1 when a ball is set.

5 is a front view of the plunger of FIG.

FIG. 6 is an enlarged view of a main part of FIG. 1 when a ball escapes.

FIG. 7 is a front view of the plunger of FIG.

FIG. 8 is a front view of a modified plunger when the ball is set.

9 is a front view of FIG. 8 when the ball is released.

FIG. 10 is a side sectional view of the torque limiter of the second embodiment.

FIG. 11 is a sectional view of a conventional torque limiter.

[Explanation of symbols]

11 ... Shaft member, 11b ... Spline, 12 ... Cylindrical member, 1
2b ... spline, 13,14 ... friction plate, 15 ... hydraulic chamber,
22, 31 ... Piston, 23 ... Plunger, 23b ... Ball escape recess, 24 ... Ball (rolling element), 25 ... Retainer,
25a ... Handle part, 26, 32 ... Lock member.

Claims (1)

[Scope of utility model registration request] 1. A shaft member having an axial spline on the outer peripheral surface, a tubular member having an axial spline on the inner peripheral surface, and a plurality of sheets guided by the spline of the shaft member so as to be movable in the axial direction. The shaft-side friction plate, the cylinder-side friction plate guided by the spline of the cylinder member so as to be movable in the axial direction, and alternately provided between the shaft-side friction plates, and the shaft-side friction plate and the cylinder-side friction plate. A piston that is pressed in the axial direction to be in pressure contact, the piston, and the friction plate that is closest to the piston are provided so as to be rollable at a predetermined pitch on the circumference,
At least one of the rolling element held by the cage, the piston interposing surface on which the rolling element is interposed, and the friction plate interposing surface are formed at the same pitch as the rolling element, and the rolling element is formed. A rolling element escape recess capable of escaping the moving body in the axial direction; a hydraulic chamber into which the piston is slidably fitted; A torque limiter characterized by having.