JPH0235251A - Motor-driven actuator - Google Patents

Abstract

PURPOSE:To decrease the number of parts used and reduce the man-hours for assembling by fitting a gear formed in a single piece from a torque transmitting segment gear and an angle transmitting segment gear on an output shaft, and meshing the angle transmitting segment gear with a gear on a potentiometer shaft. CONSTITUTION:When a motor 12 is started, rotation of motor shaft 13 is decelerated by gears 14, 16, 17, 19 and transmitted to a gear 22 and further to an output shaft 5 by means of meshing of a small gear 21 with a torque transmitting segment gear 29, and at the same time, to a potentiometer 24 by means of meshing of an angle transmitting segment gear 30 with a gear 26. When a valve is opened to a certain degree of opening to rotate the output shaft 5 for a certain angle, the meter senses it through meshing of the gears 30, 26 and emits a signal, and the motor 12 is stopped to cause stop of the valve at a certain degree of opening. Because the gears 29, 30 are formed in a single piece, the space occupied by gears is shrunk compared with the case where a separate angle transmitting gear is provided. There is no need for screw fitting the angle transmitting gear.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric actuator that reduces the rotation of a motor using a gear mechanism and outputs it as torque via an output shaft.

[Conventional technology]

As a type of actuator that outputs the rotation of a drive source as torque, an electric actuator that reduces the rotation of a motor using a gear mechanism and transmits the rotation to a driven side via an output shaft is known. When using this type of electric actuator to open and close a valve, for example, a potentiometer is installed in the transmission system to detect the rotation angle of the output shaft and display or control the opening degree of the valve. things are being done.

In this case, in the past, a potentiometer was attached to the outside of the casing housing the gear reduction mechanism, and an angle transmission gear separate from the torque transmission gear was provided on the output shaft protruding from the casing. By meshing with the gear on the potentiometer side, the rotation of the output shaft was transmitted to the potentiometer.

[Problem to be solved by the invention]

In this way, conventional electric actuators require a separate gear to transmit the rotation angle of the output shaft to the potentiometer, which increases the number of parts and assembly man-hours, increases costs, and increases the space occupied by the gear. Not only does this make the entire actuator larger, especially in the height direction, but since this gear was fixed to the output shaft with a set screw, it easily loosened and lacked shaft stability. There was a problem in that it was troublesome because it had to be tightened and loosened.

[Means to solve the problem]

In order to solve such problems, in the present invention, a gear integrally formed with a segment gear for torque transmission and a segment gear for angle transmission is mounted on the output shaft, and the segment gear for angle transmission and the gear on the potentiometer shaft are integrated. and meshed together.

[For production]

The rotation of the motor shaft is decelerated by a gear mechanism and transmitted to the driven side via the output shaft. An angle transmission segment gear is integrally formed on the torque transmission segment gear of the second output shaft and meshes with the gear of the potentiometer, so the rotation of the output shaft is transmitted to the potentiometer and the operating angle of the driven side is detected. Ru. Since both segment gears are integrally formed, the number of parts is small and the space occupied by the gears is small.

〔Example〕

This embodiment shows an example in which the present invention is applied to open and close a valve, and FIG. 1 is a plan view thereof, and FIG. 2 is a longitudinal sectional view thereof. In the figure, an actuator 1 includes a fixed base 3 connected to a driven-side valve body (not shown) by a yoke 2, and the fixed base 3 has a rectangular box shape that opens downward. A fitted cover 4 is screwed onto the screw 1. The output shaft 5 is attached to the cover 4 and the fixed base 3 with bearings 6 and 7.
The output shaft 5 is rotatably supported via the
It is connected to a valve in a valve body (not shown) via a coupling 8. Reference numeral 9 denotes a lower plate formed in a rectangular plate shape, which is close to the fixed head 3 and rotatably supported by the output shaft 5 with its movement regulated. An elongated hole 9a formed at one end of the elongated hole 9a is fitted with a bottle 10 screwed into a tapped hole of the fixed base 3 so as to be slidable in the length direction of the elongated hole 9a. Reference numeral 11 denotes an upper plate formed in a rectangular plate shape and integrated with the lower plate 9 by a stay (not shown), which is rotatably fitted to the output shaft 5, and is connected to the upper plate 9. 1 to IIJ, the morph 12 is fixed with the motor shaft 13 facing downward. A small gear 14 attached to the motor shaft 13 meshes with a rotatable and slidable gear 16 on a gear shaft 15-to which has both ends fixed to a plate 11.9 below the gear 16. A small gear 17 is integrally formed. 18
is a gear shaft fixedly supported by the lower plate 11.9 extending downward from the gear shaft 15, and this gear shaft 18
A gear 19 that meshes with the small gear 17 and a small gear 20 below it are integrally formed and rotatably fitted on the top, and the small gear 20 is connected to the small gear 21 on the gear shaft 15. It meshes with a gear 22 that is integrally formed and rotatably fitted. A compression coil spring 23 is interposed between the gear 16 and the gear 22 to spring the gear 16 upward.
6 is attached with a connecting/disconnecting mechanism (described later) that moves the mechanism to connect/disconnect the engagement between the gears 17 and 19.

On the other hand, a potentiometer 24 is fixed to the upper plate (11, ):, and a gear 26 is attached to the shaft thereof. Reference numeral 28 denotes an output shaft gear mounted on the output shaft 5, which meshes with a fan-shaped torque transmission segment gear 29 that meshes with the small gear 21 and the gear 26 of the potentiometer 24! It is integrally formed with a segment gear 30 for transmitting rotation angle in a 12-circular shape in a stepped manner,
The rotation of the small gear 21 is transmitted to the output shaft 5, and the rotation of the output shaft 5 is transmitted to the potentiometer 24.

A bottomed cylindrical bearing portion 31 is integrally formed with the cover 4 above the gear 16, and a manual disconnection pin 32 whose tip faces near the top surface of the gear 16 is attached to the bearing portion 31. The manual connection/disconnection pin 32 is supported to be movable up and down, and a compression coil spring 33 is interposed between the manual connection/disconnection pin 32 and the bottom surface of the bearing portion 31 to bias the manual connection/disconnection pin 32 upward. By doing this, the manual disconnection pin 32 is connected to the compression coil spring 3.
When pressed down against the elastic force of the compression coil spring 23, the gears 16 and 17 descend against the elastic force of the compression coil spring 23, and the small gear 17 and the gear 19 are disengaged. .

A stud 34 having a rectangular cross section is protruded from one end of the lower play 1-9, and two long and short wooden pins 35, 36 are protruded from the fixed base 3 on both sides of the stud 34. The upper end of the pin 35 is fixed to the cover 4. In addition, pin 3 is included in upper plays 1 to 11.
A notch 37 into which 5 is inserted is provided. A spring shaft 38 is fitted into the shaft hole of the stud 34 via a brim 1 with a flange so that it can move forward and backward in the axial direction.
A threaded hole of a rectangular plate-shaped play 1-39 is screwed into the threaded end portion of the plate so as to be adjustable in forward and backward movement. Further, on the bushing on the spring shaft 38, another plate 40 is attached to the plate 39.
The stud 34 and pins 35 and 36 are fitted between the plate 39 and the head of the spring shaft 38, and a compression coil spring 41 is fitted with spring receivers at both ends. It is sandwiched between 42 and 43 and stored with elastic force. A pair of switches 1 to 44 and 45 are fixed on the upper plate 11 to stop the motor I2 when the contacts are opened, and the pins 35 are opposed to the contacts. With this configuration, when the valve is fully open or fully closed, or when there is an overload on the valve side, the lower plate 11.9 and the entire gear reduction mechanism move in the forward direction or the direction around the output shaft 5. The motor 12 is horizontally rotated in the opposite direction, and the contact point of either limit switch 4/1.45 is opened by the pin 35, and the motor 12 is stopped. In this case, no matter which direction the spring shaft 38 moves with the stud 34, the plate 39 or the plate 40 will move against the pin 35.
36 restricts the movement of the compression coil spring 4.
1 is compressed and elastic force is accumulated.

The operation of the electric actuator configured as above will be explained. When the motor 12 is started, the rotation of the motor shaft 13 is reduced by the gears 14, 16, 17 1920 and transmitted to the gear 22, and then the small gear 21 and the segment gear 29
It is transmitted to the output shaft 5 by the meshing with the segment gear 3° and the gear 26, and is also transmitted to the potentiometer 24 by the meshing of the segment gear 3° and the gear 26. When the valve opens by a predetermined opening degree, the output shaft 5
When rotates by a predetermined angle, the potentiometer 24 detects this due to the meshing of the gear 30.26 and issues a signal.
The motor 12 stops and the valve stops at a predetermined opening degree. In this case, since the segment gear 29 for torque transmission and the segment gear 30 for angle transmission are integrally formed, the space occupied by the gears is smaller than when the angle transmission gear is provided separately. Further, there is no need to screw the angle transmission gear.

If the valve is overloaded due to foreign matter biting the valve during its opening operation, the reduction gear train will stop and only the motor shaft 13 will continue to rotate, causing damage to the upper and lower plates 11, 9 and the gear train. rotate around the output shaft 5 in unison. As a result, the contact of limit switch 44 or 45 is
5, the motor 12 is stopped and the coils of the motor 12 are prevented from being burnt out due to overload. In this case, the rotation of the lower plate 9 causes the spring shaft 3 to move in the forward or reverse direction via the stud 34, but the compression coil spring 41 is compressed no matter which direction it moves, so the plate 39 By adjusting the spring force of the compression coil spring 41 by rotating it forward and backward, it is possible to arbitrarily set the torque at which the plate 39 and the like begin to rotate due to overload.

Also, when the manual disconnection pin 32 is pushed down, the gears 16 and 17
is lowered and the gears 17 and 19 are disengaged, cutting off the transmission of rotation.

Although this embodiment shows an example in which the present invention is implemented for opening and closing a valve, it can be implemented in various other types of equipment and the same effects can be obtained. Further, the segment gear 28 is not limited to a spur gear, but may be a bevel gear, an internal gear, or the like.

〔Effect of the invention〕

As is clear from the above description, in the electric actuator according to the present invention, a gear integrally formed with a segment gear for torque transmission and a segment gear for angle transmission is mounted on the output shaft, and a segment gear for angle transmission and a potentiometer are mounted on the output shaft. By meshing with the gear on the shaft, the space occupied by the gear is significantly reduced compared to the conventional case where a gear for angle transmission is provided separately, and the entire actuator can be made smaller and more compact. In addition, there is no need to install a set screw for the angle transmission gear, which tends to loosen and is troublesome during disassembly and assembly, improving reliability and workability.

[Brief explanation of the drawing]

1 and 2 show an embodiment of an electric actuator according to the present invention, FIG. 1 being a plan view thereof, and FIG. 2 being a longitudinal sectional view thereof. ■... Actuator, 5... Output shaft, 12...
・ ・ ・Motor, 14, 17.20 21 ・ ・
・Small gear, 16, 19.22...Gear, 24...
・Potentiometer, 26...Gear, 2nd...
Output shaft gear, 29... Segment gear for torque transmission, 30... Segment gear for angle transmission. Patent applicant Yamatake Honeywell Co., Ltd. Agent
Masaki Yamakawa (and 2 others) ■ Procedural auxiliary equipment (voluntary) Showa d″3.9.) loFl

Claims (1)

[Claims] In an electric actuator in which rotation of a motor is reduced by a gear mechanism and transmitted to a driven side via an output shaft, a gear integrally formed with a segment gear for torque transmission and a segment gear for angle transmission is mounted on the output shaft. , An electric actuator characterized in that the angle transmission segment gear and a gear on a potentiometer shaft are meshed with each other.