JP2000074162A - Concentric speed reducer and valve device with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten the reliance upon setting of the rotation checking torque while setting the profile low. SOLUTION: An internal gear 2 and epicyclic external gear 3 are installed in a casing 1, and the rotation of an input shaft 4 having an eccentric circle part 11 is transmitted to an external gear 3 through the eccentric circle part 11, and the external gear 3 is left revolving and rotating round its own axis. The rotation is transmitted to the output shaft (valve stem) 5 through a hole 7, pin 6, output boss 14, when deceleration is made by an epicyclic gearing mechanism. The internal gear 2 is fitted to the casing 1 at the whole circumference of the oversurface by means of projection-recess fitting, wherein the fitting is maintained by a spring 18. If the torque from the input shaft 4 is below a certain value, the fitting will not be put loose, and the torque from the input shaft 4 is transmitted to the output shaft 5 upon being decelerated. If any reason causes the output shaft 5 to remain at a standstill, the torque working in the projection/recess fitting becomes over the specified value, and the internal gear 2 is depressed against the action of the spring 18, and the fitting is set off. Accordingly the eccentric motions of the external gear 3 rotate the internal gear 2 while no force is transmitted to the pin 6, and the output shaft 5 remains at a standstill. That is, the torque is shut off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentric shaft reducer in which an input shaft and an output shaft are on the same shaft center, and a valve device provided with the same.

[0002]

2. Description of the Related Art For example, a large-scale opening / closing valve V such as a butterfly valve or a ball valve shown in FIG. 1 is provided with a speed reducer D in order to improve its operability. At this time,
When the operating shaft and the output shaft (valve shaft) are at the same shaft center, operability can be improved and downsizing can be achieved, so that the concentric shaft reducer D is used.

FIG. 9 shows an example of the concentric shaft reducer D. In this reducer D, an internal gear 2 is fixed in a casing 1 and a planetary external gear is attached to the internal gear 2. 3, the input shaft 4 and the output shaft 5 on the axis of the internal gear 2 are rotatably supported and guided into the casing 1, and the input shaft 4 is provided with an eccentric circle portion 11, The planetary external gear 3 is rotatably fitted into the circular portion 11, and an output boss 14 keyed to the output shaft 5 is provided with a pin 6 parallel to the output shaft 5 around its axis. The output shaft 5 is guided into the through hole 7 of the planetary external gear 3, and the output shaft 5 is rotated at a reduced speed by the rotation of the input shaft 4 via the planetary external gear 3, the pin 6, and the output boss 14 (details). See the examples below).

In this valve device with a speed reducer D, the input shaft 4
When rotating the output shaft (valve shaft) 5 to open and close the valve by rotating the input shaft 4, the input shaft 4 can be rotated with a small force because the reduction gear D is interposed. Even if the valve element cannot move due to some reason such as the presence of an object, or if the valve is opened or closed, if the input shaft 4 is kept rotating, the valve element, the damage to the valve seat and the gear 2, 3 will be caused.

As a preventive means, a stopper is provided on the output shaft 5 side so that the output shaft 5 cannot rotate more than a required angle. It receives torque from the input shaft 4. For this reason, conventionally, as shown in FIG. 9, a torque limiter 8 is attached to a valve shaft (input shaft) 4, and the friction between the friction plate 8a and the input shaft 4 and the valve shaft 5 causing the above-mentioned breakage due to slippage exceeding a required torque. The rotation of is prevented. Since the input shaft 4 rotates more than one rotation, a stopper having a predetermined angle cannot be provided.

[0006]

When the torque limiter 8 is attached to the valve shaft 4, the height of the torque limiter 8 increases accordingly, and it is difficult to obtain a required speed reducer D for burying in soil. Also, once the friction plate 8a slips, its operating force set value changes, and its set value also differs depending on the degree of oil lubrication on the slip surface. Lack of reliability.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a speed reducer that can be reduced in height and has a high reliability in damage prevention operation.

[0008]

According to the present invention, in order to achieve the above object, a torque limiter mechanism is provided between the casing and the internal gear in the above-described concentric shaft reducer. . With this configuration, the height can be suppressed as much as possible without increasing the height.

As the torque limiter mechanism, the above-mentioned friction plate method can be adopted.
The engagement can be disengaged by a rotational force equal to or greater than the required torque, and can be a means for preventing torque transmission. With such meshing, there is no change in the operation set value.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is as follows.
An internal gear is fixed in a casing, an external planetary gear is meshed with the internal gear, and an input shaft and an output shaft on an axis of the internal gear are rotatably supported and guided into the casing. Providing an eccentric circular portion on the input shaft, rotatably fitting the planetary external gear into the circular portion, and providing an output boss integrated with the output shaft with a pin parallel to the output shaft around the axis of the output boss; The above-described known concentric shaft reducer which guides the pin into the through hole of the planetary external gear, and rotates the output shaft through the planetary external gear, the pin, and the output boss by the rotation of the input shaft. In, the internal gear in the casing,
In addition to being rotatable around its axis, the rotation preventing means is provided between the casing and the internal gear, and the rotation preventing means stops the rotation of the internal gear when an excessive rotation torque acts on the internal gear. Any configuration that is acceptable may be employed.

The above-described rotation preventing means (torque limiter)
The internal gear can be moved in the axial direction, and irregularities are formed so as to fit each other on the opposing surfaces of the internal gear and the casing in the axial direction, and the irregularities fit between the casing and the internal gear. It is possible to adopt a configuration in which a spring that biases in a full direction is provided, and when a rotation torque greater than a predetermined value acts on the internal gear, the internal gear moves in the axial direction against the spring to release the fitting of the unevenness. To rotate.

[0012] In this configuration, when the cross-sectional shape of the unevenness in the rotation direction of the internal gear is made trapezoidal, and the inclination of the oblique side on the same side and the oblique side on the other side in the rotation direction of the trapezoid are made different, The rotation prevention torque differs depending on the rotation direction, that is, the larger the inclination, the higher the rotation prevention torque. For example, the closing direction of the valve is set to the higher torque side.

The concentric shaft reducer of each of the above structures can be attached to a valve. At this time, the concentric shaft reducer is interposed between the operation shaft of the valve and the valve shaft, the input shaft is used as the operation shaft, and the valve shaft is output. Axis.

[0014]

This embodiment relates to a butterfly valve device shown in FIG. 1, and has a speed reducer D having the structure shown in FIGS.

In the speed reducer D, an internal gear 2 is provided in a casing 1 so as to be rotatable about its axis and to be movable in the axial direction, and an external planetary gear 3 is meshed with the internal gear 2. ing. Here, the number of teeth of the internal gear 2 is Z ₂ , the number of teeth of the external gear 3 is Z _3, and when the external gear 3 revolves in one direction while the internal gear 2 is fixed, the external gear 3 3 rotates in the opposite direction at a rotation speed of (Z ₂ −Z ₃ ) / Z ₃ with respect to the number of revolutions. That is, the motor rotates at a reduction ratio of (Z ₂ −Z ₃ ) / Z ₃ .

The input shaft 4 and the output shaft (valve shaft) 5 have the same axis as the internal gear 2 and are guided into the casing 1. The input shaft 4 is rotatably supported on the casing 1 by a bearing 10, and the tip thereof forms an eccentric circle 11. The external gear 3 is fitted to the eccentric part 11 via a bearing 12. Therefore, the rotation of the input shaft 4 causes the external gear 3 to revolve in the internal gear 2 and to rotate by the difference in the number of teeth.

The output shaft 5 is connected to the output boss 1 via a key 13.
4 and its output boss 14 is connected to the bush 1
The casing 5 is rotatable via the casing 5. Instead of connecting the keys 13, a spline connection may be used. The output boss 14 has a pin 6 erected about an axis parallel to the output shaft 5, and the pin 6 is guided to a through hole 7 of the external gear 3. For this reason, as shown in FIG.
, The output boss 14 (output shaft 5) transmits only the rotation of the external gear 3 through the pin 6. In this way, the rotation of the input shaft 4 is applied to the output shaft 5 by (Z ₂ −Z ₃ ) /
It is transmitted at the speed reduction ratio of Z _3. The position and the diameter of the pin 6 and the position and the diameter of the through hole 7 are appropriately selected based on the amount of eccentricity of the eccentric circular portion 11 so that a smooth deceleration operation is performed.

The upper surface of the internal gear 2 and the opposing surface of the casing 1 (the rear surface of the casing lid 1a) are irregular surfaces having a trapezoidal cross section, as shown in FIG. It is shorter in the circumferential direction than the convex surface 17 on the side. One of the slopes 16a, 17a of the convex surfaces 16, 17 has a large inclination with respect to the other slopes 16b, 17b. For example, the former is 60 degrees, and the latter is 30 degrees. The direction in which the valve element moves by the action of the torque is defined as the closing direction of the valve. Slopes 16a, 16b,
The inclination degrees of 17a and 17b are appropriately selected according to the rotation prevention torque value. By this selection, an arbitrary rotation preventing torque value can be obtained.

The casing 1 facing the lower surface of the internal gear 2
A coiled spring 18 is interposed at equally spaced positions around the inside, and the uneven surface is engaged with this spring 18. The biasing force of the spring 18 is appropriately set according to the rotation preventing torque. With this setting, the rotation prevention torque value can be set arbitrarily. The spring 18 is covered with a covered cylindrical cover 19 so that rotation of the gear 2 is not hindered.

The bearing 10 has the pin 6 fitted in a flange 10a at the lower end thereof, and rotates integrally with the output shaft 5, and a pointer plate 20 is screwed to the bearing 10. For this reason,
The degree of opening and closing of the valve V can be confirmed by checking the pointer plate 20 and the scale 21 on the upper surface of the casing 1 (lid 1a). (FIG. 3
reference).

In this embodiment, the input shaft 4 is rotated with a torque smaller than the engaging force of the springs 18 on the uneven surfaces 16 and 17, as shown in FIGS. The engagement of the surfaces 16, 17 is maintained and the internal gear 2
Does not rotate, the output shaft 5 rotates at the reduction ratio described above,
Valve V is opened and closed.

On the other hand, when the valve V is in the open / closed state, or when the valve body does not move for some reason, and when the input shaft 4 is further turned, the uneven surfaces 16, 17
6 and 7, the internal gear 2 descends against the spring 18 and the engagement between the concave and convex surfaces 16 and 17 is released. Thus, the eccentric movement of the external gear 3 rotates the internal gear 2, and the pin 6
Is not transmitted, and the output shaft 5 that takes out the rotational force via the pin 6 does not rotate. In this way, damage to the speed reducer D and the valve V is prevented.

[0023]

As described above, according to the present invention, since the torque limiter mechanism is incorporated in the casing, the height can be reduced. Further, since the torque limiter mechanism is performed by engaging and disengaging the engagement of the concave and convex surfaces, the rotation preventing action of the required torque or more becomes stable and highly reliable.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment.

FIG. 2 is a fragmentary front view of the same embodiment;

FIG. 3 is a partially cut plan view of a main part of the embodiment.

FIG. 4 is a cutaway plan view of a main part of the embodiment.

FIG. 5 is a sectional view of a main part of the embodiment.

FIG. 6 is a plan view of the essential part for explaining the operation of the embodiment.

FIG. 7 is a sectional view of an essential part for explaining the operation of the embodiment.

FIG. 8 is a diagram illustrating the operation of the embodiment.

FIG. 9 is a cutaway front view of a main part of a conventional example.

[Explanation of symbols]

 Reference Signs List 1 casing 2 internal gear 3 planetary external gear 4 input shaft 5 output shaft (valve shaft) 6 pin 7 through hole 10 bearing 11 eccentric circular portion 14 output boss 16 internal gear side convex portion 17 casing side convex portion 16a, 16b , 17a, 17b Slope 18 Internal gear pressing spring D Reduction gear V valve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H063 BB16 BB32 BB43 DB35 DB36 DC01 FF09 GG05 3J027 FA36 FA50 FB18 FB21 FB31 GB03 GC03 GD03 GD08 GD12 GE11 GE27 3J068 BA02 BB02 CB03 EE06 GA11 GA19

Claims (4)

[Claims] An internal gear 2 is fixed in a casing 1,
An external planetary gear 3 meshes with the internal gear 2, and an input shaft 4 and an output shaft 5 on the axis of the internal gear 2 are rotatably supported and guided into the casing 1, and the input shaft 4
The planetary external gear 3 is rotatably fitted into the circular portion 11, and the output boss 14 integrated with the output shaft 5 is provided with a pin 6 parallel to the output shaft 5 around its axis. The pin 6 is guided into the through hole 7 of the planetary external gear 3, and the output shaft 5 is reduced through the planetary external gear 3, the pin 6, and the output boss 14 by the rotation of the input shaft 4. In the concentric shaft reducer D to be rotated, the internal gear 2 is rotatable around the axis in the casing 1, and the casing 1 and the internal gear 2 are rotated.
The rotation preventing means is provided between the internal gear 2 and the internal gear 2 when an excessive rotation torque is applied to the internal gear 2.
A concentric shaft reducer characterized by allowing rotation of the shaft. 2. The internal gear 2 is made movable in the axial direction, and irregularities 16 and 17 are formed so as to be fitted to each other on the opposing surfaces of the internal gear 2 and the casing 1 in the axial direction. Between the internal gear 2 and the irregularities 16,
A spring 18 is provided to urge the internal gear 2 in a direction in which the internal gear 2 is fitted. The concentric shaft reducer according to claim 1, wherein the concentric shaft reducer is rotated by releasing the fitting of the unevenness (16, 17). 3. The cross-section of the irregularities 16, 17 in the rotational direction of the internal gear 2 is trapezoidal, and the oblique sides 16a, 17a on the same side and the oblique sides 16b, 17b on the other side in the rotational direction of the trapezoid. The concentric shaft reducer according to claim 2, wherein the inclination of the concentric shaft reducer is different from that of the concentric shaft reducer. 4. A concentric shaft reducer D according to any one of claims 1 to 3, interposed between an operation shaft of the valve V and the valve shaft, the input shaft 4 being an operation shaft, and the valve shaft being an output shaft. 5. A valve device with a speed reducer, characterized in that: