JPH0571821B2 - - Google Patents

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]

2. Description of the Related Art 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 conventionally known.

The general structure of a conventional electric actuator of this type will be briefly explained using FIGS. 7 to 10. The electric actuator shown by reference numeral 60 in the figures has a yoke or a fixed base on the upper part of the valve body on the driven side (not shown). (both not shown) etc. are arranged in a state in which they are interposed. Reference numeral 62 denotes an output shaft of this actuator 60, and the upper and lower plates 6 are disposed facing each other at a predetermined interval.
3 and 64, and is rotatably supported.
The lower end of the output shaft 62 passing through the lower plate 64 is connected to a valve within the valve body via a coupling (not shown). In addition, in FIG. 7, 65 is a bearing, and 66 is a spacer that also serves as a bearing. Further, 67 is a support column between the upper and lower plates 63 and 64.

70 is a motor provided on the upper surface of the upper plate 63, and a gear 7 provided on the motor shaft.
1 faces between the upper and lower plates 63 and 64,
A torque transmission gear 75 that is key-coupled to the output shaft 62 is connected to the output shaft 62 through the first, second and third stepped gears 72, 73 and 74 constituting the reduction gear mechanism. It is configured to transmit the rotation of the motor 70 while decelerating it. Note that the first and third stepped gears 72 and 74 are
As is clear from the figure, the upper and lower plates 63,
The output shaft 64 is rotatably supported on a fixed shaft 76 that is supported parallel to the output shaft 62 between the output shafts 64 and 64 .

80 is a support stand 8 on the upper surface of the upper plate 63.
With a potentiometer arranged through 1,
The potentiometer 80 is configured to detect the opening degree of the valve, etc. by detecting the rotation angle of the output shaft 62, and display or control this. 82 is a gear at the end of the detection shaft of this potentiometer 80, and 83 is integrally attached to the upper end 62a of the output shaft 62 extending through the upper plate 63 so as to mesh with this gear 82, with a set screw or the like. This is an angle transmission gear installed in the

As is clear from FIG. 10, on the upper plate 63 of the electric actuator 60 described above, there are limit switches 86 for opening and closing, which are turned on and off by cams 85, 85 provided on the output shaft 62. Furthermore, a capacitor 87 and the like are provided.

According to such an electric actuator 60, the rotation of the motor 70 is transmitted to the output shaft 62 via the gears 71 to 74 and the torque transmission gear 75, and the resulting torque is output to the shaft side of the valve. It had been. Further, the rotation angle is detected by a potentiometer 80 provided above the upper plate 63 via gears 83 and 82, and the opening degree of the valve is displayed and controlled.

By the way, in the conventional electric actuator 60 described above, which is used for driving the opening and closing of a valve, for example, a potentiometer 80 is attached to a part of the power transmission system to detect the rotation angle of the output shaft 62 and control the valve. It is common practice to display and control the opening degree and the like.

According to the conventional electric actuator 60, as described above, the upper and lower plates 63 and 64 constitute the casing in which the reduction gear mechanism and the like are housed.
A potentiometer 80 is disposed outside the gap between the two, for example above the upper plate 63, and a torque transmission gear 75 is disposed on the upper end 62a of the output shaft 62 extending through the upper plate 63. The rotation of the output shaft 62 is transmitted to the potentiometer 80 by providing a separate angle transmission gear 83 and meshing it with the gear 82 on the potentiometer 80 side.

[Problem to be solved by the invention]

However, according to the conventional electric actuator 60 as described above, the potentiometer 80 for detecting the rotation angle of the output shaft 62 is provided on the support base 81 provided above the upper plate 63, and the Separate gears 82 and 83 were provided for transmission separately from the mechanism, which not only increased the overall number of component parts and assembly man-hours, resulting in higher costs, but also increased the space occupied by the gear mechanism, especially for the actuator. There was a problem in that the entire 60 was increased in size in the height direction.

The present invention has been made in view of these circumstances, and aims to reduce the overall number of component parts, improve ease of assembly, and reduce costs. It also reduces the space occupied by the gear mechanism, and in particular reduces the overall number of components. The purpose of this invention is to obtain an electric actuator that can be downsized in the height direction.

[Means to solve the problem]

In order to meet such demands, the electric actuator according to the present invention reduces the rotation of the motor using a gear mechanism disposed in the gap between the upper and lower plates, and transmits the rotation to the driven side via the output shaft. Standing tall,
An output shaft gear, which is configured by integrally forming a torque transmission segment gear and an angle transmission segment gear, is pivotally attached to a portion located in the gap between the upper and lower plates of the output shaft. A gear mechanism that transmits rotation from the motor is meshed with the segment gear for transmitting torque of the output shaft gear, and a potentiometer for detecting the rotation angle of the output shaft is installed, with its meter shaft facing the gap between the upper and lower plates. The gear on the meter shaft of this potentiometer is configured to mesh with the angle transmission segment gear.

[Effect]

According to the present invention, the rotation of the motor shaft is decelerated by the gear mechanism and transmitted to the driven side via the torque transmission segment gear of the output shaft gear mounted on the output shaft. The segment gear for torque transmission is integrally formed with the segment gear for angle transmission, and it meshes with the gear on the meter shaft of the potentiometer in the gap between the upper and lower plates, so the rotation of the output shaft is controlled by the potentiometer. The operating angle of the driven side is detected. In the present invention, both the torque transmission segment gear and the angle transmission segment gear are integrally formed as an output shaft gear, and the gear connection with the motor and potentiometer is performed on the upper and lower plates. Since this is carried out in the space between the actuators, not only the number of component parts is small, but also the space occupied by the gear mechanism in the entire actuator is small.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

Figures 1 to 6 show an embodiment of the electric actuator according to the present invention, and in these figures, in this embodiment, the electric actuator indicated by reference numeral 1 is used to open and close a valve. Explain.

In these figures, electric actuator 1
The yoke 2 is connected between the valve body on the driven side (not shown).
A cover 4 formed in the shape of a rectangular box opening downward is screwed to the fixed base 3. The cover 4 and the fixed base 3 have an output shaft 5 with a bearing 6,
The output shaft 5 is rotatably supported via a coupling 8, and the output shaft 5 is connected via a coupling 8 to a valve in a valve body (not shown).

Reference numeral 9 denotes a lower plate formed in a substantially rectangular plate shape, and in this embodiment, it is close to the fixed base 3 and rotatably supported on the output shaft 5 with vertical movement restricted. Further, a long hole 9a formed at one end of the lower plate 9 is fitted with a pin 10 screwed into a screw hole of the fixed base 3 so as to be slidable in the length direction of the long hole 9a.

Reference numeral 11 denotes an upper plate formed in a rectangular plate shape, which is integrated with the lower plate 9 by a stay (not shown) and arranged at a predetermined interval, and is rotatably fitted to the output shaft 5. are combined.
A motor 12 is fixed on the upper plate 11 with a motor shaft 13 facing downward. A small gear 14 mounted on the motor shaft 13 meshes with a rotatable and slidable gear 16 on a gear shaft 15 whose both ends are fixed to the upper and lower plates 11 and 9. A small gear 17 is integrally formed.

A gear shaft 18 is fixedly supported by the upper and lower plates 11 and 9 parallel to the gear shaft 15, and on this gear shaft 18 is a gear 19 that meshes with the small gear 17, and a gear 19 below the gear shaft 18. The small gear 20 is integrally formed and rotatably fitted, and the small gear 20
is in mesh with a gear 22 integrally formed with a small gear 21 on the gear shaft 15 and rotatably fitted therein. A compression coil spring 23 is interposed between the gear 16 and the gear 22 to force the gear 16 upward.
A connecting/disconnecting mechanism (described later) is attached to disconnect/disconnect the meshing between the gear 19 and the gear 19.

On the other hand, a potentiometer 24 for detecting the rotation angle of the output shaft 5 is fixed on the upper plate 11, and a gear 26 is rotatably mounted on the meter shaft.

Reference numeral 28 denotes an output shaft gear mounted on the output shaft 5 by press fitting or the like, and as is clear from FIGS. 1 to 5, it is a fan-shaped torque transmitting gear that meshes with the small gear 21. The segment gear 29 and the segment gear 30 for transmitting rotational angle, which is approximately semicircular and meshes with the gear 26 on the potentiometer 24 side, are integrally formed in a stepped manner. is transmitted to the output shaft 5 side, 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. It is supported so that it can move up and down. A compression coil spring 33 is interposed between the manual disconnection pin 32 and the bottom surface of the bearing portion 31 to bias the manual disconnection pin 32 upward. and,
By pressing down this manual disconnection pin 32 against the elastic force of the compression coil spring 33, the gears 16, 17 are
descends against the elastic force of the compression coil spring 23,
The small gear 17 and the gear 19 are configured to be disengaged from each other.

Further, according to this embodiment, a stud 34 having a rectangular cross section is provided at one end of the lower plate 9, and two pins 35, 36, a long pin and a short pin, are provided on both sides of the stud 34. protrudes from the fixed base 3, and the upper end of the pin 35 is fixed to the cover 4. Note that the upper plate 11 is provided with a notch 37 into which the pin 35 is inserted. A spring shaft 38 is fitted into the shaft hole of the stud 34 via a bush with a flange so that it can move forward and backward in the axial direction. The holes are screwed together so that they can be adjusted forward and backward.

Further, in this embodiment, another plate 40 is fitted onto the bush on the spring shaft 38 so as to sandwich the stud 34 and the pins 35 and 36 between the plate 39 and the bush. 39
A compression coil spring 41 is interposed between the spring shaft 38 and the head of the spring shaft 38, with both ends thereof being held by spring receivers 42 and 43 to accumulate elastic force. Then, the motor 1 is placed on the upper plate 11 by opening the contacts.
A pair of limit switches 44, 4 for stopping 2.
5 is fixed, and the pin 35 is opposed to its contact point (not shown).

In the structure of this embodiment, when the valve is fully open or fully closed, and when there is an overload on the valve side, the upper and lower plates 11 and 9 and the entire reduction gear mechanism are connected to the output shaft 5.
horizontally rotates in the forward or reverse direction around
and one of the limit switches 44, 45
The contact point is opened by the pin 35, and the motor 12 stops. In this case, together with the stud 34, the spring shaft 3
No matter which direction the plate 8 moves, the movement of the plate 39 or the plate 40 is restricted by the pins 35 and 36, so that the compression coil spring 41 is compressed and elastic force is accumulated.

The operation of the electric actuator 1 according to the present invention having the above configuration will be described below.

That is, in the normal power transmission operation, as is clear from FIG. 3, by starting the motor 12, the rotation of the motor shaft 13 is transferred to the gear 14 on this shaft 13 and the gear shaft 15 that meshes with the gear 14. The speed is sequentially reduced through a gear 16 which is supported on a shaft and meshes with the gear 14, and a gear 17 that is integrated with the gear 14, a gear 19 that is supported on a gear shaft 18 and meshes with the gear 17, and a gear 20 that is integrated with the gear. The signal is transmitted to the gear 22 which is rotatable on the gear shaft 15. Then, due to the meshing of the small gear 21 integrated with this gear 22 and the segment gear 29, the output shaft gear 28 having this segment gear 29 is transmitted to the output shaft 5 which is attached to the shaft, and at the same time, the output is output. The gear 2 is pivotally supported on the meter shaft of the potentiometer 24 by a segment gear 30 that is integrally formed with the shaft gear 28.
6, the signal is transmitted to the potentiometer 24.

Therefore, the valve opens by a predetermined opening degree and the output shaft 5
When is rotated by a predetermined angle, the potentiometer 24 detects this due to the meshing of the gears 30 and 26 and issues a signal. As a result, motor 12
When the valve is stopped, the valve is stopped at a predetermined opening degree. In this case, a segment gear 29 for torque transmission,
Since the segment gear 30 for angle transmission is integrally formed as the output shaft gear 28 and is disposed interposed in the gap between the upper and lower plates 11 and 9, the segment gear 30 for angle transmission This means that the space occupied by the gear is reduced compared to when the gear is provided separately.

In addition, in the structure of this embodiment, if a foreign object gets stuck in the valve during the opening operation of the valve and an overload occurs, the reduction gear mechanism train stops and only the motor shaft 13 attempts to continue rotating. Upper and lower plates 11,
9 and the gear train rotate together around the output shaft 5.

As a result, the contacts of the limit switch 44 or 45 are opened by the pin 35, so 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 lower plate 9
The rotation of the spring shaft 38 causes the spring shaft 38 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.
The compression coil spring 4 is moved forward and backward by rotating the plate 39.
By adjusting the spring force No. 1, it is possible to arbitrarily set the torque at which the plate 39 and the like start rotating due to overload.

On the other hand, when the manual disconnection pin 32 is pressed down,
Its tip touches the upper surface of gear 16, and this gear 1
6 is configured to move downwardly on the gear shaft 15. Additionally, the gear 17 integrated with this gear 16 also descends, and the mesh with the gear 19 is disengaged.
As a result, rotation is no longer transmitted to the output shaft 5 and the potentiometer 24 (the gears 14 and 16 are in mesh with each other).

Here, the reason why such manual power disconnection is necessary is that when a valve equipped with an electric actuator 1 like the one in this embodiment is manually operated, the setting This is effective when making adjustments. Furthermore, when the gear train is connected to the motor 24, the holding torque (detent torque) of the motor 24 is increased by the reduction gear mechanism, so the rotational torque of the main shaft increases, and rotation transmission is interrupted. This is because automatic operation would be difficult without manual connection and disconnection.

According to the electric actuator 1 according to the present invention configured as described above, both segment gears 29 and 30 for torque transmission and angle transmission are provided.
is integrally formed as the output shaft gear 28, and the gear connection with the motor 12 and potentiometer 24 is performed within the gap between the upper and lower plates 11 and 9, so the number of component parts is small. In addition, there is an advantage that the space occupied by the gear mechanism in the entire actuator 1 is small.

In this embodiment, the present invention is applied to an electric actuator for driving the opening and closing of a valve, but the present invention can be applied to various other devices, 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 explained above, according to the electric actuator of the present invention, the segment gear for torque transmission that transmits the rotation of the motor to the output shaft via the gear mechanism and the potentiometer for detecting the rotation angle of the output shaft are gear-coupled. An output shaft gear integrally formed with a segment gear for angle transmission is pivotally attached to a portion located above the output shaft in the gap between the lower plates,
A gear mechanism for transmitting rotation from the motor is meshed with the segment gear for torque transmission, and a potentiometer for detecting the rotation angle of the output shaft is arranged so that its meter shaft faces the gap between the upper and lower plates. and the gear on the meter shaft is configured to mesh with the angle transmission segment gear, so despite the simple configuration, the angle transmission gear is configured separately and the potentiometer is connected above the upper plate. Compared to the conventional structure in which a gear is connected to the meter shaft of the meter, the space occupied by the gear mechanism can be significantly reduced, the number of component parts can be reduced, assembly performance can be improved, and the entire actuator can be made smaller and more compact. It has the excellent effect of being able to be configured as follows.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing one embodiment of the electric actuator according to the present invention, FIG. 2 is a schematic side view showing the cover broken away, and FIG.
- Developed view shown in cross section along the W-X-Y-Z line, No. 4
The figure is a developed view showing the case where the manual disconnection pin is pressed down from the state shown in Fig. 3, and Fig. 5 is the - of Fig. 1.
6 is a developed view taken along the Y-Z line in FIG. 1, FIG. 7 is a schematic side view illustrating an example of a conventional electric actuator, and FIGS. 8 and 9 are FIG. 7. - line, - line sectional view, 1st
FIG. 0 is a schematic perspective view for explaining the appearance of a conventional electric actuator. 1...Electric actuator, 5...Output shaft, 12...
Motor, 14, 17, 20, 21...Small gear, 1
6, 19, 22... Gear, 24... Potentiometer, 26... Gear, 28... Output shaft gear, 29... Segment gear for torque transmission, 30... Segment gear for angle transmission.

Claims (1)

[Scope of Claims] 1. In an electric actuator that reduces the rotation of a motor using a gear mechanism disposed in a gap between a pair of upper and lower plates and transmits it to a driven side via an output shaft, for torque transmission. An output shaft gear configured by integrally forming a segment gear and an angle transmission segment gear is pivotally attached to a portion located above the output shaft in the gap between the lower plates, and this output shaft gear A gear mechanism for transmitting rotation from the motor is meshed with the torque transmitting segment gear of the motor, and a potentiometer for detecting the rotation angle of the output shaft is connected so that its meter shaft faces the gap between the upper and lower plates. An electric actuator characterized in that the potentiometer is arranged in such a manner that a gear on a meter shaft of the potentiometer is meshed with the angle transmission segment gear.