JPH07293576A - Torque limiter - Google Patents

Abstract

PURPOSE:To provide the torque limiter which cuts off power at the time of over loading, and concurrently hold surely a power cut-off position. CONSTITUTION:In the torque limiter 1 which can connect a torque limiter shaft 3 to a transmission shaft 6 in such a way that they can be connected to/ disconnected from each other with an engaging member 4 pressed by a pressing member 10 energized by a press spring 8, the pressing member 10 is slidably inserted in the torque limiter shaft 3 in a state that a hold ball 7 is loosely coupled in its support cylinder 13, and a hold cylinder 20 provided with an escape groove 7a internally coupling the hold ball 7 in a state of power transmission is provided in such a way that it can be slid in the support cylinder 13 and the torque limiter shaft 3. A weak tension spring 15 is provided between the support cylinder 13 and the hold cylinder 20, when the aforesaid engaging member 4 is moved to the direction that power is cut off, against the press spring 8 at the time of over loading, the hold ball 7 is fitted in a hold groove 3a formed in the torque limiter shaft 3 at the inner circumferential surface of the hold cylinder 20, and the pressing action of the engaging member 4 caused by the press spring 8 is thereby released, so that power is kept at a cut-off condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque limiter capable of keeping a torque limiter shaft and a transmission shaft in a power cut state at the time of overload.

[0002]

2. Description of the Related Art Conventionally, as a torque limiter for transmitting power by engaging an engaging member formed between a torque limiter shaft and a transmission shaft in a meshed state by a pressing spring at a time of normal load. A cam surface type or a ball hole surface type engaging member that meshes in a concave-convex shape at the time of overload is in a non-transmission state while repeating intermittent power supply due to the pressing force of the pressing spring and overload.

[0003]

In the above-mentioned conventional torque limiter, the power transmission is not reliably cut off at the time of overload, and intermittent engagement is repeated, and this intermittent engagement causes wear of the engaging member at an early stage. Moreover, there is a problem that it is accompanied by noise. Therefore, the present invention solves the above-mentioned problems of the prior art, can surely cut off the power by the set load, can surely maintain the cut state, and can easily perform the return transmission thereof, which is easy to handle. The purpose is to provide a torque limiter.

[0004]

A torque limiter 1 of the present invention presses a torque limiter shaft 3 and a transmission shaft 6 into a pressing spring 8.
Engaging member (ball 4) by the pushing member 10 biased by
In a torque limiter that presses against and connects so as to be separable, the pushing member 10 is held by the support cylinder 13 on the holding ball 7.
Is slidably inserted into the torque limiter shaft 3 in a loosely fitted state, and the holding cylinder 20 having the escape groove 7a into which the holding ball 7 is fitted in the power transmission state is provided with the supporting cylinder 13.
Further, the torque limiter shaft 3 is slidably provided, and a tension spring 15 weaker than the pressing spring 8 is provided between the support cylinder 13 and the holding cylinder 20, so that the engagement member 4 can be operated when overloaded.
Is moved in the power cutting direction against the pressing spring 8,
By the movement of the holding cylinder 20, the holding ball 7 is fitted into the holding groove 3a formed in the torque limiter shaft 3 on the inner peripheral surface thereof, so that the pressing of the engaging member 4 by the pressing spring 8 is released and the power is cut off. Configured to hold.

[0005]

[Operation] With the above configuration, the engaging member (ball 4) 4
Is engaged with the torque limiter shaft 3 and is rotationally transmitted at a set torque. When an overload is generated on the transmission shaft 6 side and the torque exceeds a set torque, the engagement member 4 disengages the transmission shaft 6 against the pressing spring 8 and disconnects the power. At this time, the holding ball 7 is fitted into the holding groove 3a and is fixed by the holding cylinder 20 so that the pushing member 10 is held properly at the power cut position.

Further, by pushing the holding cylinder 20 to the original position, the holding ball 7 is released into the escape groove 7a, whereby the holding of the pushing member 10 is released and the torque limiter 1 is put into the transmission state again.

[0007]

EXAMPLES Examples of the present invention will be described with reference to the drawings. 1 shown in FIG. 1 is a torque limiter of a type conveniently installed in a path for transmitting power from a prime mover to a binding machine in a binder (not shown) of an agricultural machine,
Axial core line A- of the same figure of the support shaft 2 rotatably supported on the machine body
The configuration above A represents the power transmission state, and the configuration below it represents the power disconnection state.

A torque limiter shaft 3 is provided at the shaft end of the support shaft 2.
Is fixed by a bolt, and a shaft plate 5 is projected and fixed in a flange shape at the central portion of the outer circumference of the torque limiter shaft 3, and an appropriate number of ball holes 4a are opened in the shaft plate 5 and Hold the ball 4 as an engaging member in a loosely fitted state,
An input pulley 5a is fixed to one outer surface thereof. Further, a transmission shaft 6 having a sprocket 6a is fitted on the torque limiter shaft 3 on the left side of the shaft plate 5 via a metal bush 6d, and a shaft plate 6c is fixed to an end of the transmission shaft 6. Further, the shaft plate 6c is formed with a conical hole-shaped engagement hole 6b for engaging the ball 4 in a power transmitting state, and a stopper ring 6e provided on the torque limiter shaft 3 is provided on the shaft 6. It is adapted to come into contact with the end portion to prevent lateral movement of the transmission shaft 6.

The torque limiter shaft 3 on the right side is provided with a holding groove 3a into which a holding ball 7 described later is fitted and locked, and a screw portion 3 in which a nut 9 is screwed so that the pressing force of a pressing spring 8 can be adjusted.
Slide the pushing member 10 that forms b and has a pushing surface 11 capable of pushing the ball 4 and a support cylinder 13 having a holding hole 12 for holding the holding ball 7 by a proper number of loose fits. It is possible to insert. A tension spring 15 having a pressing force weaker than that of the pressing spring 8 is provided on the support cylinder 13 and the torque limiter shaft 3, and a relief groove 7a for the holding ball 7 is provided on the inner peripheral surface in a power transmitting state. Holding tube 2
0 is slidably inserted.

The pressing spring 8 is fitted onto the holding cylinder 20, and the right end of the pressing spring 8 is positioned by a pressing piece 21 having a slit 21a that engages with the nut 9.
0 is pressed with an appropriate pressing force, whereby the ball 4 is engaged with the engaging hole 6b of the shaft plate 6c provided on the transmission shaft 6 side, and power transmission with a predetermined torque set is possible. Two
Reference numeral 5 is a grip cover for covering the spring cover 8a and the pressing piece 21, and is attached by a screw 26 to a projecting piece 20a fixed to the end of the holding cylinder 20 projecting movably in the slit 21a. [Power transmission state] With the above configuration, the power input from the pulley 5a drives the shaft plate 5 as shown in the upper half of FIG. 1, and is adjusted by the nut 9 screwed to the end of the torque limiter shaft 3. By pushing the ball 4 by the pushing member 10 pushed by the pushing spring 8 which fits the ball 4 into the engaging hole 6b, the sprocket 6a provided on the transmission shaft 6 can be attached to an arbitrary driven portion with an appropriate set torque. Transmission can be done through. [Power non-transmission state] At this time, if an overload occurs on the driven portion side of the binding machine (not shown) or the like, the rotation of the transmission shaft 6 output via the sprocket 6a decreases, and the transmission state is changed to a stop state. If so, the ball 4 is attached to the shaft plate 6 provided on the transmission shaft 6.
When the pushing member 10 is pushed in the direction of the right arrow F against the pushing spring 8 by being pushed by the slope of the engaging hole 6b of FIG.
As shown below the shaft core line AA of the ball 4 and the shaft plate 6
c, that is, the engagement with the transmission shaft 6 is released, and the transmission is disconnected.

In this case, the pushing member 10 moves to a position where the holding ball 7 is fitted into the holding groove 3a, and
Allow the free extension of the tension spring 15 and slide the holding cylinder 20 to the right. Then, the relief groove 7a of the holding cylinder 20
The holding ball 7 is extruded by the inclined surface formed inside and is fitted into the holding groove 3a properly, and the holding ball 7 maintains the fitted state on the inner peripheral surface of the holding cylinder 20.

As a result, the pushing member 10 securely holds the ball 4 in the power-off state without pressing it strongly. Therefore, it is possible to prevent troubles such as breakage caused by driving the driven portion in the overloaded state and early wear of the engaging portion and the like formed by the ball 4 and the engaging hole 6b. Also, after removing the overload factor of the driven part,
By pushing the grip cover 25 in the direction of the arrow G and sliding the holding cylinder 20 to the transmission position (upper half state of FIG. 1) against the tension spring 15, the holding ball 7 is fitted and retracted into the escape groove 7a. This releases the holding ball 7. Then, the pushing member 10 is pushed by the pushing spring 8 so that the ball 4 is again engaged with the engaging hole 6b of the transmission shaft 6 to return to the transmission state.

Incidentally, the transmission of the torque limiter 1 may be carried out by inputting it to the transmission shaft 6 side and transmitting the output of the torque limiter shaft 3 side contrary to the structure described above. Further, it is possible to configure the support shaft 2 as a transmission shaft on the input or output side without providing the pulley 5a.

[0014]

In the torque limiter according to the present invention, the torque limiter shaft 3 and the transmission shaft 6 are connected to each other by pressing the engaging member 4 by the pressing member 10 biased by the pressing spring 8. In the torque limiter, the push-out member 10 is slidably inserted into the torque limiter shaft 3 in a state in which the holding ball 7 is loosely fitted in the support cylinder 13, and the holding ball 7 is internally fitted in a power transmission state. The holding cylinder 20 having 7a is attached to the support cylinder 13 and the torque limiter shaft 3.
Is provided slidably, and a tension spring 15 weaker than the pressing spring 8 is provided between the support cylinder 13 and the holding cylinder 20 so that the engaging member 4 resists the pressing spring 8 in the power cutting direction at the time of overload. When the holding cylinder 20 is moved, the holding ball 7 is fitted into the holding groove 3a formed in the torque limiter shaft 3 by the movement of the holding cylinder 20 to release the pressing of the engaging member 4 by the pressing spring 8. The power is maintained in a disconnected state.

Therefore, when an overload occurs on the driven side, the pushing member 10 is pushed by the engaging member (ball 4) against the pushing spring 8 and the holding member including the holding balls 7 and the like disengages the power. Therefore, the power can be surely cut off, and the wear of the power connecting / disconnecting portion such as the engaging member 4 can be prevented. Further, since the power disconnection holding mechanism is composed of the pushing member 10 and the holding tube 20 slidably fitted on the torque limiter shaft 3, it is easy to manufacture and can be assembled into a compact and compact structure. The return operation can be facilitated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure and action of a torque limiter, in which an upper half shows a power transmission state and a lower half shows a power non-transmission state.

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

[Explanation of symbols]

1 Torque limiter 2 Support shaft 3 Torque limiter shaft 3a Holding groove 4 Engaging member (ball) 5 Shaft plate 6 Transmission shaft 6a Sprocket 6b Engagement hole 6c Shaft plate 6d Metal bush 6e Stopper ring 7 Holding ball 7a Relief groove 8 Pressing spring 10 Pushing member 13 Support tube 15 Tension spring 20 Holding tube 21 Pressing piece 21a Slit 25 Grip cover

Claims (5)

[Claims] 1. A torque limiter for connecting a torque limiter shaft (3) and a transmission shaft (6) by a pressing member (8) biased by a pressing spring (8) to press the engaging member (4) so that the engaging member (4) can be connected and disconnected. 10 is slidably inserted into the torque limiter shaft 3 in a state in which the holding ball 7 is loosely fitted in the support cylinder 13, and the holding cylinder 20 having the escape groove 7a for internally fitting the holding ball 7 in the power transmission state is provided. The support cylinder 13 and the torque limiter shaft 3 are slidably provided,
A tension spring 15 that is weaker than the pressing spring 8 is provided between the support cylinder 13 and the holding cylinder 20, and when the engaging member 4 is moved in the power cutting direction against the pressing spring 8 when overloaded, the holding spring 15 is held. By the movement of the cylinder 20, the holding ball 7 is formed on the inner peripheral surface thereof.
The torque limiter is configured to release the pressure of the engagement member 4 by the pressure spring 8 to hold the power in a disconnected state by fitting the lever into the holding groove 3a formed in the torque limiter shaft 3. 2. A shaft plate 6c is provided on a hollow transmission shaft 6 which is loosely fitted and supported on a torque liter shaft 3, and a shaft plate 5 having a pulley 5a is fixed to one surface of the shaft plate 6c, and is fixed to a support cylinder 13 on the other surface. The pushing members 10 face each other, and the balls 4 fitted in the ball holes 4a provided in the shaft plate 5 are fitted and supported. The balls 4 are engaged holes provided on the surface of the shaft plate 6c in a power transmission state. 6. The structure according to claim 1, which is configured to be fitted in 6b.
Torque limiter described. 3. The pushing member 10 is fixed to a support cylinder 13 supported by the torque limiter shaft 3, and one end thereof is supported via a pressing piece 21 supported by a nut 9 screwed to the torque limiter shaft 3. The torque limiter according to claim 1, wherein the torque limiter is configured to be pressed against the shaft plate 5 by the pressing spring 8. 4. A cylindrical holding groove 3a into which a ball 7 is fitted is formed on the outer surface of the torque limiter shaft 3 in the circumferential direction, and the ball 7 is formed in a portion of the holding cylinder 20 facing the holding groove 3a.
2. The torque limiter according to claim 1, wherein the escape groove 7a is formed, and the escape groove 7a is formed with an inclined surface on the pushing member 10 side. 5. A grip cover 25 is provided so as to cover the nut 9 for adjusting the pressing force of the pressing member 10 screwed onto the end of the torque limiter shaft 3, and the holding cylinder 20 is moved by this grip cover 25. Ball 7 fitted in holding groove 3a
The torque limiter according to claim 1, wherein the torque limiter is configured to be released into the relief groove 7a provided on the inner surface of the holding cylinder 20.