JPS631822A - Encapsulated liquid torque limiter - Google Patents

Abstract

PURPOSE:To eliminate the necessity for stopping a drive unit immediately after interruption of transmission of torque, by encapsulating liquid in a cylinder bore and a discharge path thereby transmitting the torque without retreating a piston. CONSTITUTION:Force is applied in the retreating direction onto a piston 42 by the function of convex concave faces 48 of a ball 46, but since oil is encapsulated in a cylinder bore 40 and a discharge path 62 and the opening of the discharge path 62 is closed by a piston 72, the piston 42 does not retreat, nor a detection ring 30 retreat while resisting against the energizing force of a belleville spring 34. Consequently, the rotary driving force of a drive unit is normally transmitted to a driven device through the engagement between the ball 46 and the concave face 48, thus eliminating the necessity for stopping the drive unit immediately after interruption of transmission of torque.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a torque limiter that is provided between a driving device and a driven device, and transmits torque below a set value, but does not transmit torque exceeding the set value. It is.

A type of conventional torque limiter transmits torque by engaging an engaging concave portion and an engaging convex portion, and when the transmitted torque exceeds a set value, the engaging convex portion resists the urging force of the urging means. There are some cases in which torque is not transmitted by separating from the engagement recess. This type of torque limiter is generally
A first rotating body and a second rotating body that are provided to be relatively rotatable around the axis and not relatively movable in the axial direction, and a detection device that is provided to be relatively movable in the axial direction but not relatively rotatable with respect to the second rotating body. a member, a biasing means for biasing the sensing member toward the first rotary body, and a biasing means provided on the sensing member and the first rotary body, respectively, and engaging with each other to cause the sensing member and the first rotary body to move toward each other. An engaging concave portion and an engaging convex portion that transmit torque to a rotating body and separate from each other while causing the detection member to retreat against the urging means when the transmitted torque exceeds a set value. Constructed to include.

This type of torque limiter has a simple structure and -
Even if the state is such that torque is not transmitted, it is possible to return to the state where torque is transmitted by engaging the engagement recess and the engagement protrusion.

However, if the drive device continues to rotate after the transmission torque exceeds the set value and the engagement convex part disengages from the engagement concave part, the engagement concave part and the engagement convex part will repeatedly engage and disengage. A shocking load is applied to the drive device, and a shocking driving force is applied to the driven device, which may cause damage to the drive device, torque limiter, or driven device. , the generation of noise is unavoidable.

Therefore, in this type of torque limiter, a limit switch or the like detects the movement of the detection member when the engagement protrusion disengages from the engagement recess, and immediately stops the drive device.

Problems to be Solved by the Invention However, in this case, an electric control device is required to detect the movement of the detection member and immediately stop the drive device, resulting in a problem of increased equipment cost.

In view of this point, the present invention provides a torque limiter in which torque is not transmitted when the engagement protrusion is disengaged from the engagement recess, but there is no need to immediately stop the drive device after the torque transmission is cut off. It was done in order to

Means for Solving the Problems Therefore, the present invention provides the first rotating body, the second rotating body,
In a torque limiter equipped with a detection member, a biasing means, an engagement recess, and an engagement protrusion, a cylinder bore parallel to the axial direction is formed in the first rotating body, and a piston is fitted into the cylinder bore in a fluid-tight and slidable manner. At the same time, the piston is provided with the above-mentioned engaging convex portion, while the second rotary body always closes the opening of the discharge passage extending from the cylinder bore, so that the engaging convex portion is completely removed from the engaging concave portion. The main feature is that a closing means is provided to open the discharge passage when the first rotary body and the second rotary body rotate relative to each other by an angle greater than the angle required for separation, and a liquid is sealed in the cylinder bore and the discharge passage. be.

Function: While the torque limiter configured as described above is in a torque transmitting state, a force in the backward direction is applied to the piston by the action of the engagement recess and the engagement protrusion, but there is no liquid in the cylinder bore and discharge passage. Since the piston is enclosed, the piston does not move back, which hinders the transmission of torque.

When the transmitted torque exceeds the set value, the detection member is moved backward against the biasing means by the action of the engagement recess and the engagement protrusion, and the engagement protrusion is disengaged from the engagement recess. Accordingly, the first rotating body and the second rotating body rotate relative to each other by a certain angle, and the closing means opens the discharge passage. At this point, the biasing force of the biasing means is acting on the piston via the detection member, so if the discharge passage is opened, the piston will quickly retreat while discharging the liquid in the cylinder due to this biasing force. The engaging convex portion does not engage with the engaging concave portion.

Effects of the Invention As described above, the present invention takes advantage of the fact that in an enclosed state, a liquid that acts similar to a rigid body easily flows out when the discharge passage is opened, and it is as if the liquid had never existed from the beginning. It is something. In order to open the discharge port, the relative rotation between the first rotating body and the second rotating body is used. In this case, the first rotating body and the second rotating body can continue to rotate relative to each other without any problem.

Therefore, it is not necessary to detect the movement of the detection plate and immediately stop the drive device as in the conventional case, and an electric control device for this purpose is not required, resulting in an effect of reducing equipment costs. Further, it is also possible to prevent noise from being generated due to repeated engagement and disengagement between the engagement protrusion and the engagement recess.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a front view showing a main part of a torque limiter according to an embodiment of the present invention in cross section. In this figure, reference numeral 10 indicates a shaft driven by a drive device (not shown) such as a motor. A drive rotating body 14 is fixed to this shaft 10 by a key 12. This drive rotating body 14 has a small diameter portion 1
6, and a driven rotating body 18 is rotatably supported on this small diameter portion 16 via a radial bearing metal 20. The driven rotor 1 has a larger diameter than the large diameter portion of the drive rotor 14. It is sandwiched from both sides by the large diameter portion of the drive rotor 14 and the NAND 26 via the thrust bearing metals 22 and 24, and is immovable relative to the drive rotor weight 4 in the axial direction.

A detection ring 30 serving as a detection member is slidably fitted on the outer circumferential surface of the large diameter portion of the drive rotary body 14 . A key (not shown) is provided between the detection ring 30 and the drive rotary body 14, thereby preventing relative rotation between the two. An adjustment nut 32 is screwed into a threaded portion formed on the outer circumferential surface of the drive rotor 14.
A disc spring 34 as a biasing means is disposed between the detection ring 2 and the detection ring 30, and biases the detection ring 30 toward the driven rotating body 18. This biasing force can be adjusted by rotating the adjustment nut 32. Further, a thrust bearing metal 36 is disposed between the 'l★ know ring 30 and the driven rotating body 18.

A plurality of axial cylinder bores 40 (three in the illustrated example) are provided in the portion of the driven rotating body 18 that faces the detection ring 30
(Solid) As shown in FIG. 2, the angular intervals between the two are slightly different. A piston 42 is fluid-tightly and slidably fitted into each cylinder bore 40, and its forward end position is defined by a shoulder surface 44. A ball 46 is rotatably attached to the front end of the piston 42, and when the piston 42 is at the forward end position, the ball 46 engages with a concave spherical surface 48 as an engagement recess formed in the detection ring 30. It is made to be. The ball 46 serves as an engaging protrusion.

Plug 54 and piston 4 forming the rear wall of cylinder bore 40
2, a tension coil spring 56 is attached via spring retainers 58 and 60,
The piston 42 is always urged in the backward direction. A discharge passage 62 extends from the cylinder bore 40 and opens at a position facing the end surface of the large diameter portion of the drive rotor 14 .

A countersunk hole is formed at the opening of the discharge passage 62, and an O-ring 64 is disposed inside the countersunk hole. The counterbore hole is formed to a depth such that the O-ring 64 slightly protrudes from the end face of the driven rotating body.

A cylinder bore 70 is formed in the axial direction in a portion of the driving rotary body 14 facing the O-ring 64, and a piston 72 is fitted into the cylinder bore in a fluid-tight and slidable manner. The forward end position of the piston 72 is also defined by the shoulder surface 76, and at this forward end position, the piston 72 is just aligned with the O-ring 64.
The discharge passage 62 is closed by contacting the discharge passage 62.

A through hole is formed in the portion of the thrust bearing metal 22 that corresponds to the cylinder bore 70, so that the piston 72 can be inserted into the O-ring 6.
4, an annular groove 78 is formed in the circumferential direction from this through hole with a width slightly larger than the outer diameter of the O-ring 64.

A plurality of radial grooves 80 further extend from this annular groove 78, and communicate the annular groove 78 with a gap 82 between the driving rotary body 14 and the driven rotary body 18. piston 72
is constantly biased in the backward direction by a tension coil spring 88 disposed between the plug 86 and the plug 86.

A discharge passage 90 is extended from the cylinder bore 70,
It is opened on the outer circumferential surface of the drive rotary body 14. A countersunk hole is formed in this opening, into which an O-ring 92 is fitted, and although the discharge passage 90 is normally closed by the inner peripheral surface of the detection ring 30, the ball 46 is removed from the concave spherical surface 48. It is designed to be opened when the detection ring 30 is retracted to the point where it is about to be completely detached.

Although not shown, the driving rotary body 14 and the driven rotary body 18 each have an oil supply passage for supplying oil to the cylinder bores 70 and 40, respectively, and a check valve provided at the opening of the oil supply passage. an exhaust passage for allowing air to flow out from the cylinder bores 40, 70 and the exhaust passage 62°90 when oil is supplied from the plug, and a plug for closing the opening of the exhaust passage. The cylinder bore 40.
70 and discharge passages 62.90 are filled with oil.

When using this torque limiter, the driven rotating body 1
The rotating body of the driven device is connected to the driven rotating body 18 by using a plurality of bolt holes 94 formed in the end face of the drive unit 8 opposite to the detection ring 30 .

When the shaft 10 is rotated by a drive device such as a morph in this state, the drive rotor 14 rotates integrally, and this rotation is transmitted to the detection ring 30 by a key (not shown). Then, the rotation of the detection ring 30 is caused by the concave spherical surface 48.
By the engagement between the ball 46 and the ball 46, the force is transmitted to the driven rotating body 18, and from there to the driven device, causing the driven device to rotate. At this time, the convex spherical surface of the ball 46 and the concave spherical surface 4
A force in the backward direction is applied to the piston 42 due to the action of Piston 42
does not retreat. Further, the detection ring 30 does not move backward against the biasing force of the disc spring 34. Therefore, normally, the rotational driving force of the driving device is transmitted to the driven device by the engagement between the ball 46 and the concave spherical surface 48. Ru.

However, if the rotation of the driven device is prevented for some reason, the retraction force of the detection ring 30 based on the action of the convex spherical surface and the concave spherical surface 48 of the ball 46 will overcome the biasing force of the disc spring 34. The detection ring 30 moves back. The detection ring 30 detects that the transmitted torque exceeds the set value.

Accordingly, the driven rotating body 18 rotates by a small angle relative to the detection ring 30 and the driving rotating body 14. Therefore, although the piston 72 also moves relative to the Q-ring 64, its front end surface does not come off the O-ring 64.
The passage 62 continues to be closed.

Then, just before the ball 46 completely leaves the concave spherical surface 48, the discharge passage 9 is closed by the detection ring 30.
0 is opened and oil is allowed to flow out from the cylinder bore 70. This causes piston 72 to be retracted by tension coil spring 88 and away from O-ring 64 to open exhaust passage 62 . That is, these cylinder bores 70° pistons 72. Tension coil spring 88. The discharge passage 90, the detection ring 30, and the like constitute a closing means that normally closes the discharge passage 62 and opens it when the detection ring 3° retreats. When the discharge passage 62 is opened, oil is allowed to flow out from the cylinder bore 40, so the piston 42 is quickly moved backward by the biasing force of the disc spring 34, and after the detection ring 30 contacts the thrust bearing metal 36, is further moved back a small distance by the biasing force of the tension coil spring 56.

In other words, the ball 46 is retracted from the thrust bearing metal 36, and the piston 72 is also retracted from the thrust bearing metal 22, so that from now on, the driving rotation is performed while the driven rotary body 18 is stopped. Even if the body 14 and the detection ring 30 continue to rotate, the ball 4
6 does not engage the concave spherical surface 48, nor does the piston 72 contact the O-ring 64. Further, since the annular groove 78 is formed in the thrust bearing metal 22 as described above, the thrust bearing metal 22 does not come into sliding contact with the O-ring 64. Furthermore, the pores discharged from the cylinder bore 40 are supplied from the annular groove 78 between the thrust bearing metal and the driven rotating body 18 to lubricate these sliding surfaces, and further pass through the radial groove 80 and the gap 82 to the thrust bearing metal. Since the contact surface between the metal 36 and the detection ring 30 is lubricated, generation of frictional heat is effectively suppressed. The same applies to the oil discharged from the cylinder bore 70.

In this way, after the present torque limiter is in a state where torque transmission is cut off, the drive rotating body 14 and the detection ring 30 are
Since there is no problem even if the drive unit continues to rotate, there is no need to immediately stop the drive unit, and an electrical control unit for this purpose can be omitted.

Further, after the problem on the driven device side is resolved, the driven rotating body 18 and the detection ring 30 are reengaged via the balls 46, but as described above, the plurality of cylinder bores 40 are unequal. Due to their angular spacing, they can only engage in one relative phase position, and the drive and driven devices are always coupled in a fixed relative phase.

FIG. 3 shows parts of another embodiment of the present invention that differ from the above embodiment. In this embodiment, a relatively small ball 9 is attached to the front end of the piston 72 provided on the drive rotary body 14 side.
6 is attached, and when the piston 72 is at the forward end position, this ball 96 closes the opening of the discharge passage 62 formed in the driven rotating body 18. Further, the fitting clearance between the piston 72 and the cylinder bore 70 is intentionally made slightly larger, so that the ball 96 does not open the discharge passage 62 due to the minute relative rotation between the driving rotor 14 and the driven rotor 18. It is like that.

However, if the load on the driven rotating body 18 becomes excessive and the detection ring 30 retreats by a relatively small distance, the driven rotating body 18 and the driving rotating body 14 rotate relative to each other by a small fixed angle.
The ball 96 opens the discharge passage 62, and the piston 42 and the ball 46 move to 11! , allow to retreat. Therefore, in this embodiment, there is no need for the detection ring 30 to be retracted until the ball 46 leaves the concave spherical surface 48.

FIG. 4 shows yet another embodiment of the invention. In this embodiment, no piston is provided on the driving rotary body 14 side, and the discharge passage 62 is directly closed by the thrust bearing metal 22. That is, a circumferential groove 100 shown in FIG. 5 is formed on the surface of the thrust bearing metal 22 that contacts the driven rotating body 18, but this! 100 is cut in a part, and a closing protrusion 102 is formed in that part, and as shown in an enlarged view in FIG. 62, and in this embodiment, the closing protrusion 102 serves as the closing means.

This closing protrusion 102 does not retract like the piston 72 in the above embodiment even in the torque transmission cutoff state, so it comes into contact with the O-ring 64 every time the drive rotating body 14 rotates once. Since the corner portion 104 is rounded, the O-ring 64 will not collapse fJ6.

Further, in this embodiment, a lock nut 108 is provided in addition to the nut 26, and the thrust bearing metal 22
．． Driven rotating body 18. After properly adjusting the gap between the thrust bearing metal 24 and the nut 26, the nut 26 can be completely fixed to the drive rotor 14.

A lock nut 110 is also provided for the detection ring 30.

Since other parts are the same as those in the previous embodiment, corresponding parts are given the same reference numerals to indicate correspondence, and detailed explanation will be omitted.

The three embodiments of the present invention have been described above based on the drawings, but
It goes without saying that the present invention can be implemented in various other forms with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view of a torque limiter according to an embodiment of the present invention. FIG. 2 is a side view of a torque limiter that is an embodiment of the present invention. 3 and 4 are front sectional views showing essential parts of torque limiters which are different embodiments of the present invention. FIG. 5 is a view taken along arrow A in FIG. 4. Figure 6 is B- in Figure 5.
It is a sectional view of B. 14; Driving rotating body 18: Driven rotating body 30: Detection ring 34: Belleville spring 40 cylinder bore 42: Piston 46: Ball
48: Engagement recess 62: Discharge passage 70 Niji cylinder bore 72: Piston 90: Discharge passage 9
6: Ball 100: Groove 102: Closure protrusion

Claims (1)

[Claims] A first rotating body and a second rotating body that are provided to be relatively rotatable around one axis but not relatively movable in the axial direction, and provided to be movable relative to the second rotating body in the axial direction but not relatively rotatable. a sensing member; a biasing means for urging the sensing member toward the first rotating body; and a biasing means provided on the sensing member and the first rotating body, respectively, so that the sensing member and the first rotating body are engaged with each other. an engaging concave portion and an engaging convex portion that transmit torque between the first and second points, and separate from each other while retracting the detecting member against the urging means when the transmitted torque exceeds a set value; Of the first and second rotating bodies,
In a torque limiter that is connected to a driving device and the other is connected to a driven device to transmit torque below a set torque, a cylinder bore parallel to the axial direction is formed in the first rotating body, and a piston is inserted into the cylinder bore. is fluid-tightly and slidably fitted to provide the engagement convex portion on the piston, while the second rotating body always closes the opening of the discharge passage extending from the cylinder bore, A closing means is provided for opening the discharge passage when the first rotary body and the second rotary body rotate relative to each other by an angle greater than an angle necessary for the engagement protrusion to completely disengage from the engagement recess, and the cylinder bore and the discharge passage are closed. A liquid-filled torque limiter characterized by having a passage filled with liquid.