JPH0972389A - Hollow shaft reduction gear with overload protecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate a torque regulating work and repair of an overload protection device. SOLUTION: An engaging recessed part 13 and a handling recessed part 14 are formed in a drive plate 8 brought into a detent state and axially movably mounted on the end part of a hollow output shaft 2 exposed from a gear case 1 to the outside and an opposite surface to a driven plate 11 fixed to the end part of a driven shaft 7 protruded from the end part of the output shaft 2 in such a manner to correspond to the drive plate 8. A ball 15 is held between the recessed parts 13 and 14 and the drive plate 8 is energized through the force of a spring 16 in a direction in which the drive plate approaches the driven plate 11. When overload torque is exerted on the driven shaft 7, the ball 15 is escaped from an engaging recessed part 13 against the energizing force of the spring 16, and the drive plate 11 is slipped over the drive plate 8. The energization force of the spring 16 is regulated by a regulating nut 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow shaft reducer provided with an overload protection device.

[0002]

2. Description of the Related Art A conventional hollow shaft reducer has a structure in which a driven shaft is inserted and connected to an output shaft formed in the hollow of the speed reducer. As shown in FIG. 22 is
By penetrating the inside of the gear case 21, the bearings 23, 23
It is rotatably supported.

A worm wheel 33 meshing with a worm 26 connected to a drive source is attached to the output shaft 22, and the rotation of the worm 26 causes the output shaft 22 to rotate at a reduced speed. In the gear case 21, facing the worm wheel 33,
The plate 31 is provided so as to rotate integrally with the output shaft 22 and slide in the axial direction.

A hemispherical hole 25 is formed on the surface of the worm wheel 33 facing the plate 31, and a hemispherical hole 34 corresponding to the hemispherical hole 25 is also formed on the plate 31, and a ball is formed between them. 35 is interposed. The plate 31 is constantly urged toward the worm wheel 33 by a spring 36, and holds the ball 35 between the hemispherical holes 25 and 34 of the worm wheel 33 and the plate 31. When the worm wheel 33 is rotated by the drive source via the worm 26, the drive torque is transmitted to the output shaft 22 via the balls and the plate 31.

When an overload torque is applied to the driven shaft connected to the output shaft 22, the plate 31 moves in the direction away from the worm wheel 33 against the biasing force of the spring 36, and the plate 31 or The ball 35 escapes from the hemispherical hole of the worm wheel 33,
A slip occurs between 3 and plate 31.

[0006]

In the conventional hollow shaft reducer configured as described above, it is difficult to adjust the transmission torque because the overload protection device is provided in the gear case. There was a problem that the gear case had to be disassembled when performing the adjustment.
Further, when repairing the overload protection device or replacing parts, it is necessary to disassemble the gear case, which makes the work difficult.

Therefore, the present invention solves the above-mentioned problems of the prior art, and provides a hollow shaft reducer with an overload protection device which can easily perform torque adjustment work and repair of the overload protection device. The purpose is to provide.

[0008]

In order to achieve the above object, the first hollow shaft reducer with an overload protection device of the present invention is a hollow output shaft rotatably supported through a gear case. And a driven shaft which is inserted into the output shaft so as to be rotatable only with respect to the output shaft, and an end portion of the output shaft which protrudes from the gear case to the outside so that rotation is prevented and axial movement is possible. The mounted drive plate, the driven plate fixed to the end of the driven shaft protruding from the end of the output shaft so as to face the drive plate, and one of the facing surfaces of the drive plate and the driven plate. An engaging recess formed on the other side, a holding recess formed on the other side, a ball held between the engaging recess and the holding recess, a spring urging the drive plate toward the driven plate, The fixed position of the driven packing plate is adjusted in the axial direction of the driven shaft and a spring pressure adjusting mechanism for adjusting the spring pressure of the spring. The engaging recess and the holding recess are formed in a shape that allows the ball to be released from the engaging recess when the ball is held in the holding recess when an overload acts on the driven shaft.

The spring pressure adjusting mechanism is screwed to a male screw portion formed on the tip side of the driven plate at the end portion of the driven shaft and the male screw portion to move the driven plate. It is preferable to provide an adjusting nut for preventing the above.

The second hollow shaft reducer with an overload protection device of the present invention is a hollow output shaft that penetrates through the gear case and is rotatably supported, and only rotates with respect to the output shaft. Of the driven shaft that is inserted into the output shaft, the drive plate that is fixed to the end of the output shaft that projects outward from the gear case, and the driven shaft that projects from the end of the output shaft. A driven plate that is fixed to the end so as not to rotate and is movable in the axial direction so as to face the drive plate, an engaging recess formed in one of the facing surfaces of the drive plate and the driven plate, and the other in the other. A holding recess, a ball held between the engaging recess and the holding recess, a spring for urging the driven plate toward the drive plate, and a spring pressure adjusting mechanism for adjusting the spring pressure of the spring. It is provided. The engaging recess and the holding recess are formed in a shape that allows the ball to be released from the engaging recess when the ball is held in the holding recess when an overload acts on the driven shaft.

The spring pressure adjusting mechanism is screwed to a male screw portion formed on the tip side of the driven plate at the end portion of the driven shaft and the male screw portion to compress the spring. It is preferable to provide an adjusting nut for adjusting

[0012]

In the first hollow shaft reducer with the overload protection device, the rotation of the output shaft is transmitted to the drive plate, and from the drive plate, it is transmitted to the driven plate through the balls to drive the driven shaft. It is driven to rotate. Then, when an overload torque is applied to the driven shaft, the balls held between the engaging recess formed in one of the drive plate and the driven plate and the holding recess formed in the other drive plate The plate is moved in the direction away from the driven plate against the biasing force of the spring, and is released from the engagement recess while being held in the holding recess, and the driven plate is slipped with respect to the drive plate.

In the first type, when the fixed position of the driven plate is adjusted in the axial direction of the driven shaft by the spring pressure adjusting mechanism, the compression amount of the spring changes and the drive plate is biased toward the driven plate. The spring pressure changes and the magnitude of the load torque that the driven plate slips can be adjusted.

The spring pressure adjusting mechanism prevents the movement of the male screw portion formed on the tip side of the driven plate at the end portion of the driven shaft and the driven plate screwed to the male screw portion. In the case of being constituted by an adjusting nut, by rotating the adjusting nut, the fixed position of the driven plate changes in the axial direction of the driven shaft,
The magnitude of the load torque that the driven plate slips from the drive plate is continuously adjusted.

Further, in the second hollow shaft reducer with the overload protection device, the rotation of the output shaft is driven by the drive plate through the ball and the driven plate, similarly to the first shaft. Transmitted to the shaft. When an overload torque is applied to the driven shaft, the balls held between the engaging recess formed in one of the drive plate and the driven plate and the holding recess formed in the other are driven by the driven plate. The plate is moved in the direction away from the drive plate against the biasing force of the spring, and is released from the engagement recess while being held in the holding recess, and the driven plate is slipped with respect to the drive plate.

In the second aspect, the magnitude of the load torque that the driven plate slips is adjusted by adjusting the spring pressure with the spring pressure adjusting mechanism. In the second one, the spring pressure adjusting mechanism has a male screw portion formed on the tip side of the position of the driven plate at the end portion of the driven shaft, and the compression of the spring screwed to the male screw portion. When it is composed of an adjusting nut that adjusts the amount, the amount of compression of the spring changes by rotating the adjusting nut, and as a result, the spring pressure that biases the driven plate toward the drive plate changes. The magnitude of the load torque at which the driven plate slips from the drive plate is continuously adjusted.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a first embodiment of a hollow shaft reducer with an overload protection device of the present invention, in which a gear case 1 has a hollow output shaft 2 penetrating the inside thereof and bearings 3 and 3.
It is rotatably supported by.

At the center of the hollow output shaft 2, a worm wheel 5 is fixed by a key 4, and the worm wheel 5 meshes with a worm 6 rotated by a drive source such as a motor. A driven shaft 7 is inserted into the hollow output shaft 2 so as to be rotatable only with respect to the hollow output shaft 2. A disk-shaped drive plate 8 is attached to the end of the hollow output shaft 2 exposed from the gear case 1.

The drive plate 8 has a key 10 fitted in a key groove 9 formed in the hollow output shaft 2.
With respect to the hollow output shaft 2, the rotation is stopped, and the output shaft 2 is mounted so as to be movable only in the axial direction. Further, the end of the driven shaft 7 projects from the end of the hollow output shaft 2, and a disk-shaped driven plate 11 is attached to the end so as to face the drive plate 8. ing.

Drive plate 8 and driven plate 1
A conical engagement concave portion 13 and a hemispherical holding concave portion 14 are formed on the surface facing 1 respectively so as to face each other, and a steel ball 15 is fitted between the concave portions 13 and 14. Is held.

Driven plate 1 of drive plate 8
A disc spring 16 is arranged on the surface opposite to the surface facing 1 and the drive plate 8 is biased toward the driven plate 11 side by the elastic force of the disc spring 16.

The driven plate 11 is attached to the driven shaft 7 with its rotation being restricted by a key 12. Further, on the tip side of the end of the driven shaft 7 with respect to the part where the driven plate 11 is mounted,
A male screw part 17 is formed, and the driven plate 11 is driven by the driven plate 7 by an adjusting nut 18 screwed therein.
The movement in the axial direction is restricted so as not to slip out from the end.

The male screw portion 17 and the adjusting nut 18 constitute a spring pressure adjusting mechanism for adjusting the fixed position of the driven plate 11 in the axial direction of the driven shaft 7 to adjust the spring pressure of the disc spring 16. .

In the above-mentioned structure, when the worm 6 connected to the drive source is rotationally driven, the rotation of the worm 6 is decelerated and transmitted to the hollow output shaft 2 via the worm wheel 5. Then, as the hollow output shaft 2 rotates, the drive plate 8 rotates.

As shown in FIG. 2, the live plate 8 is
Since the disc spring 16 is pressed against the opposing driven plate 11 side, when the torque applied to the driven shaft 7 is less than or equal to the rated value, it is formed on the opposing surfaces of the drive plate 8 and the driven plate 11. The rotation is transmitted to the driven plate 11 via the ball 15 sandwiched between the engaged recess 13 and the holding recess 14, and the rotation is transmitted to the driven shaft 7 connected by the key 12 and the driven plate 11. Transmitted.

When the load torque exceeds the rated value, the balls 15 move in the direction of separating the drive plate 8 from the driven plate 11 against the urging force of the disc spring 16, as shown in FIG. Let drive plate 8
And slips out between the drive plate 8 and the driven plate 11.

In this embodiment, the drive plate 8
The engaging recess 13 on the side is formed in a conical shape, while the holding recess 14 on the side of the driven plate 11 is formed in a hemispherical shape, so that when the overload torque is applied, the ball 1
No. 5 comes out from the conical surface of the engagement recess 13 on the drive plate 8 side, but the holding recess 14 on the driven plate 11 side
The ball 15 remains held in the holding recess 14 of the driven plate 11 and does not fall downward. Therefore, if the recesses 13 and 14 of the drive plate 8 and the driven plate 11 are rotated to the opposite positions, the ball 15 can be held again between the recesses 13 and 14 by the biasing force of the disc spring 16.

The magnitude of the torque transmitted to the driven shaft 7 is adjusted by rotating the adjusting nut 18, and
If the positions of the driven plate 11 and the drive plate 8 are displaced to the right in FIG. 1 by 8 and the disc spring 16 is displaced to the right in FIG. The limit torque that slips with respect to 8 increases, and the torque is reduced by displacing to the left.

Next, FIG. 4 shows a second embodiment of the present invention. This embodiment is different from the first embodiment described above only in the internal structure of the hollow reducer, and the other parts have the same structure. Therefore, in FIG. 4, the members in FIG. The same members as those in FIG. 2 are given the same numbers as those in FIG. In this embodiment, a driven spur gear 5A, which is a hollow output shaft 2A supported by bearings 3A and 3A, is fixed to a gear case 1A by a key 4A, and the driven spur gear 5A has a drive side spur gear. 6A is engaged.

The drive side spur gear 6A is a gear case 1A.
Is fixed to a drive shaft 6B supported by bearings 3B and 3B, and the hollow output shaft 2A is rotationally driven by rotationally driving the drive shaft 6B by an external drive source (not shown). The rotation of the output shaft 2A is performed by the drive plate 8, the balls 15,
It is transmitted to the driven shaft 7 via the driven plate 11.

FIG. 5 shows a third embodiment of the present invention. In this embodiment, a disk-shaped drive plate 8'is integrally provided at the end of the output shaft 2'of the hollow shaft reducer (not shown). On the other hand, at the end of the driven shaft 7 ′ protruding from the end of the output shaft 2 ′, the key 1
The disk-shaped driven plate 11 'is stopped from rotating with respect to the driven shaft 7'by 2'and is attached so as to be movable only in the axial direction.

A plurality of hemispherical holding recesses 14 'for holding the balls 15' are formed in the drive plate 8'in the circumferential direction, and the driven plate 11 'faces the holding recesses 14'. A conical engagement recess 13 'with which the ball 15' is engaged is formed at the position.

The driven plate 1 at the end of the driven shaft 7 '
A disc spring 16 ′ for urging the driven plate 11 ′ toward the drive plate 8 ′ side is mounted on the tip side of the mounting position of 1 ′. The disc spring 16 ′ has a male screw portion 1 on the tip side of the driven shaft 7 ′ with the pressing ring 20 interposed therebetween.
The adjustment nut 18 'screwed to the 7'is pressed so as not to come off from the shaft end of the driven shaft 7'. Male screw part 1 formed on the tip side of the driven shaft 7 '.
The 7'and the adjusting nut 18 'screwed to the 7'constitute a spring pressure adjusting mechanism for adjusting the spring pressure of the disc spring 16'.

In this embodiment, when the hollow output shaft 2'rotates, the drive plate 8'provided integrally with the hollow output shaft 2'rotates to the driven shaft 7'through the ball 15 'and the driven plate 11'. Transmitted. And the driven shaft 7 '
If the load torque applied to the ball becomes excessive, the ball 15 '
The driven plate 11 ′ is separated from the drive plate 8 ′ against the urging force of the disc spring 16 ′, disengaged from the engagement recess 13 and the driven plate 11 ′ is slipped with respect to the drive plate 8 ′. At this time, the ball 15 '
Is held between the holding recess 14 ′ and the surface of the driven plate 11 ′ facing the drive plate 8 ′, and does not drop downward.

The magnitude of the load torque with which the ball 15 'is disengaged from the engaging recess 13 can be adjusted by adjusting the spring pressure of the disc spring 16' by the adjusting nut 18 '. In this embodiment, the drive plate 8'is formed integrally with the hollow output shaft 2 ', but these are separate bodies,
The drive plate 8'may be fixed to the output shaft 2'by a key or the like.

In each of the above-described embodiments, the disc spring is used to hold the ball between the holding recess of the drive plate and the engaging recess of the driven plate, but the present invention is not limited to this. Instead, other types of springs such as compression coil springs can be used. Further, the spring pressure adjusting mechanism for adjusting the spring pressure of the disc spring is composed of a male screw portion formed on the tip end side of the driven shaft and an adjusting nut screwed to the male screw portion. The spring pressure adjusting mechanism is not limited to the configurations of these embodiments, and in the first and second embodiments described above, the position for fixing the driven plate to the driven shaft is adjusted. Anything is possible as long as it is possible.

For example, as another spring pressure adjusting mechanism, a plate facing the driven plate is fixed to the tip end side of the driven plate at the end of the driven shaft, and a plurality of adjusting bolts abutting the driven plate are attached to the plate. It is possible to provide a structure in which a screw hole for screwing is provided concentrically with the driven shaft, and the fixing position of the driven plate is adjusted in the axial direction by adjusting the adjusting bolt.

Further, in the third embodiment, the spring pressure adjusting mechanism may be one that can adjust the compression amount of the spring for urging the driven plate. For example, the shaft of the driven shaft. A plate or the like for preventing the spring from coming off may be attached to the end, and a disc spring may be arranged on the driven shaft between the driven plate and the plate and the amount of compression thereof may be adjusted by a shim or the like.

Further, as a coupling means between the output shaft and the drive plate and between the driven plate and the driven shaft,
A means such as a spline may be used instead of the means using a key. Further, as an example of the hollow shaft reducer with an overload protection device of the present invention, an example of a reducer using a worm reducer and a spur gear has been shown, but the present invention is not limited to these examples. Instead, it can be applied to various types of hollow shaft reducers such as a helical gear, a bevel gear, and a hypoid gear.

In each of the embodiments described above, the engaging recess for engaging the ball is formed in a conical shape, and the retaining recess for holding the ball is formed in a hemispherical shape. The recess may have a shape in which the ball moves the drive plate or the driven plate against the spring when the overload torque acts, and the engagement state is released, such as a quadrangular pyramid-shaped recess. It may be one. Further, the holding recess may have any shape as long as it can hold the ball when an overload torque acts, and may be, for example, a cylindrical hole having a depth such that a part of the ball projects.

[0041]

As described above, a ball is interposed between the end of the hollow output shaft exposed to the outside of the gear case and the end of the driven shaft protruding from the end of the output shaft. Since the drive plate and the driven plate for transmitting the torque are arranged and the spring pressure adjusting mechanism for adjusting the urging force of the ball spring is provided in the engaging recess, the transmission torque can be easily adjusted.

When the spring pressure adjusting mechanism has a structure for adjusting the spring pressure by rotating an adjusting nut screwed with a male screw portion formed on the tip side of the end of the driven shaft, the transmission torque The size of can be precisely adjusted.

Further, according to the hollow shaft reducer with the overload protection device of the present invention, when overload torque acts and slip occurs between the drive plate and the driven plate, these plates are restored to their original positions. The work of returning to the position can be easily performed. At that time, it is possible to visually confirm that the ball has engaged with the engagement concave portion and also to confirm by the engagement sound, so that the ball and the engagement concave portion can be reliably engaged.

Further, the parts constituting the overload protection device such as the drive plate, the driven plate, the ball and the spring can be easily attached and detached without disassembling the gear case. The parts replacement work can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a hollow shaft reducer with an overload protection device of the present invention.

FIG. 2 is a cross-sectional view of an essential part of the first embodiment showing a state during normal torque transmission.

FIG. 3 is a cross-sectional view of an essential part of the first embodiment showing a state in which overload torque is applied.

FIG. 4 is a sectional view showing a second embodiment of the hollow shaft reducer with the overload protection device of the present invention.

FIG. 5 is a cross-sectional view of essential parts showing a third embodiment of the hollow shaft reducer with the overload protection device of the present invention.

FIG. 6 is a partial cross-sectional view showing an example of a conventional hollow shaft reducer with an overload protection device.

[Explanation of symbols]

 1,1A Gear case 2,2A, 2 'Output shaft 7,7' Driven shaft 8,8 'Drive plate 11,11' Driven plate 13,13 'Engagement recess 14,14' Holding recess 15,15 'Ball 16 , 16 'Belleville spring 17, 17' Male screw part 18, 18 'Adjustment nut

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[Procedure amendment]

[Submission date] September 26, 1995

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (4)

[Claims] 1. A hollow output shaft that is rotatably supported through the gear case, a driven shaft that is inserted into the output shaft so as to be rotatable only with respect to the output shaft, and an outside of the gear case. A drive plate that is mounted on the protruding end of the output shaft so as not to rotate and is movable in the axial direction, and an end of the driven shaft protruding from the end of the output shaft that faces the drive plate. Driven plate fixed in place, an engaging recess formed in one of the facing surfaces of the drive plate and the driven plate, and a holding recess formed in the other surface, and a ball held between the engaging recess and the holding recess. A spring for urging the drive plate toward the driven plate, and a spring for adjusting the spring pressure of the spring by adjusting the fixed position of the driven plate in the axial direction of the driven shaft. A pressure adjusting mechanism, and the engagement recess and the holding recess are formed in a shape that allows the ball to be released from the engagement recess when the ball is held in the holding recess when an overload acts on the driven shaft. Hollow shaft reducer with overload protection device. 2. The spring pressure adjusting mechanism is screwed to a male screw portion and the male screw portion formed on the tip side of the position of the driven plate at the end portion of the driven shaft, and the spring force adjusting mechanism of the driven plate. The hollow shaft reducer with an overload protection device according to claim 1, further comprising an adjusting nut for preventing movement. 3. A hollow output shaft rotatably supported by penetrating the inside of the gear case, a driven shaft inserted into the output shaft so as to be rotatable only with respect to the output shaft, and an outside of the gear case. A drive plate fixed to the end of the output shaft protruding to the end of the drive shaft, and a drive plate fixed to the end of the driven shaft protruding from the end of the output shaft so as to be axially movable and opposed to the drive plate. A mounted driven plate, an engaging recess formed in one of the facing surfaces of the drive plate and the driven plate, and a holding recess formed in the other surface, and a ball held between the engaging recess and the holding recess. A spring for urging the driven plate toward the drive plate, and a spring pressure adjusting mechanism for adjusting the spring pressure of the spring, wherein the engagement recess and the holding recess are overloaded on the driven shaft. There overload protector with a hollow shaft reduction gear, characterized in that it is formed into a can escape shape from the engagement recess in a state in which the ball is held in the holding recess when acted. 4. The spring pressure adjusting mechanism is screwed to a male screw portion formed on a tip side of a position of the driven plate at an end portion of the driven shaft and the male screw portion, and The hollow shaft speed reducer with an overload protection device according to claim 3, further comprising an adjusting nut for adjusting a compression amount.