EA002335B1 - An electrically operated valve or damper actuator having an electric motor directly coupled to the actuator drive shaft - Google Patents

Abstract

1. An electrically operated actuator for operating a valve or damper having an actuating shaft that has an operational torque requirement greater than 10 Nm, said electrically operated actuator comprising: (i) a housing, (ii) a drive shaft rotatably mounted within the housing and having a first end which extends from the housing for direct coupling to the actuating shaft of the valve or damper, (iii) an electric motor capable of developing a torque greater than 10 Nm axially mounted on the drive shaft, and (iv) means for controlling the operation of the motor. 2. An actuator according to claim 1 wherein the electric motor is a variable speed, permanent magnet, constant torque electric motor. 3. An actuator according to claim 2 wherein the electric motor is a high torque, direct current motor operated by pulse width modulation. 4. An actuator according to claim 3 wherein the electric motor is adapted to provide an infinitely variable output speed of the drive shaft over a predetermined speed range. 5. An actuator according to claim 3 wherein the electric motor is adapted to provide a constant torque over a predetermined speed range. 6. An actuator according to claim 1 wherein the rotor is rotatably mounted on the drive shaft and wherein the actuator further inclues a clutch for coupling the rotor to the drive shaft. 7. An actuator according to claim 6 wherein the clutch inclues a drive sleeve slidably mounted on the drive shaft but not rotatable with respect to the drive shaft, drive pins on the drive sleeve, drive pins on the rotor and spring means for normally biasing the drive sleeve towards the rotor so that the drive pins are engaged. 8. An actuator according to claim 7 and further including cam means adapted to engage the drive sleeve and move the drive sleeve away from the rotor against the action of the spring means to disengage the drive pins. 9. An actuator according to claim 8 wherein the other end of the drive shaft is connected to a hand wheel adapted to rotate the drive shaft when the drive pins are disengaged. 10. An actuator according to claim 1 wherein the means for controlling the operation of the electric motor is a motor drive control comprising circuitry to drive and protect the motor and a human interface control adapted to set the operational parameters of the actuator. 11. An actuator according to claim 10 wherein the control means inclues a microprocessor programmed to allow the operational parameters to be set and to generate an alarm when any setting is exceeded. 12. An actuator according to claim 10 wherein the human interface control allows the operational parameters to be set from a local or remote location.

Description

Field of Invention

This invention relates to electrically driven primary devices, more specifically, to electrically actuated actuators for opening, closing and / or changing the position of valves and gate valves in order to regulate the flow of fluid in networks and pipelines.

Known level

Automatic regulation of fluid flows in industrial networks and pipelines is widely applicable in areas such as power generation, oil, oil and gas processing, pulp and paper, chemical, food, petrochemical, water treatment and water treatment industries. To date, the actuators used single-speed asynchronous AC motors, which were connected to the actuator via a worm gear combined with the actuator.

One of the drawbacks of such known systems is that a combination of various motors and gearboxes is required to provide the required output speeds, resulting in an increase in equipment fleet. In addition, usually to change the required speed, it is necessary to replace the components or model of the engine, because each combination of motor and gearbox has its own constant output speed.

Another disadvantage of the known systems is that to provide a given output torque in a wide speed range, a large gamut of engines is required. In order to reduce costs, it is common practice to limit the number of engines used, which leads to a decrease in torque when speeds increase.

Another disadvantage of the known systems is that when a gearbox is present, wearing surfaces (and friction losses) appear between the motor and the drive output shaft.

Known actuators vary in the degree of availability of electronic and mechanical functions within the system for setting up equipment and for field adjustment. However, the presence of these functions entails some problems, including disassembling for physical adjustments, which causes downtime, and all work related to access to parts requires disconnecting the supplied voltage for safety reasons, as well as tolerances.

Most well-known mechanisms have the ability to manually control them in case of power failure. At such moments, it is important to consciously control these actions manually in order to maintain position indication and not lose the original calibration. Some standard actuators now available have sophisticated gear systems to provide position indication.

Summary of the invention

According to one feature of the invention, there is an electrically controlled actuator for acting on the shutter or valve with a moment of driving the actuator rod of the actuator more than 10 Nm and consisting of (I) a hollow housing, (II) a drive shaft that is mounted for rotation in the housing and which has one the end protrudes from the housing for articulation with the drive rod of the shutter or shutter, (III) an electric motor with a rotor and a stator, capable of creating a torque of more than 10 Nm and installed in the housing, with a rotor, with clearly mounted on the shaft, and a stator fixedly secured within the housing, (IV) operation control devices of the motor.

In a preferred embodiment of the invention, there is a single coupling device for the electric motor and the drive shaft — a coupling.

A preferred variable speed electric motor with a constant magnet and constant torque is a high torque DC motor controlled by pulse width modulation (PWM).

A PWM-controlled DC motor with a permanent magnet provides any variable output speed (in increments of 1 rpm) in the speed range from minimum to maximum. Thus, one embodiment of the invention can replace from 6 to 12 different actuators for combinations of DC motors and gearboxes of the prior art. The speed of the electric motor can be changed in a predetermined range by changing the PWM duty cycle settings (from the remote control on the equipment, on the remote control or from a remote location). Two embodiments of the present invention can replace 24 different combinations of a DC motor and gearboxes of the prior art (nomenclature of one supplier), which leads to a smaller stock of spare parts and makes it possible to avoid changing the circuit to change the speed / torque ratio.

Permanent magnet DC motor provides constant torque across the entire speed range.

With the axial location of the electric motor and the direct connection of the shaft, the wearing surfaces in the gearbox, which is required in known systems, disappear. This invention provides an improved mechanical efficiency, since friction losses inherent in the built-in gearboxes of known systems disappear. An advantage of the invention is that positioning and adaptive control during manual operations are achieved without complex gears.

The electric motor consists of a stator and a rotor. The stator is connected to a three-phase solid-state semiconductor switching device, which is powered by a DC voltage from a three-phase rectifier. By turning on the solid-state device, the electric motor turns into an alternating current motor. Thus, the switching device acts as an inverter.

By controlling a solid-state switching device using a pulse-width modulated (PWM) signal, you can smoothly change the speed of the electric motor from minimum to maximum. An electric motor can also be developed for a given speed range with the required torque.

The microprocessor controls the PWM signal for speeds that are set as operating parameters, and supports these speeds using a rotor position sensor.

If the speed starts to drop due to the load applied to the shaft, the microprocessor linearly changes the PWM signal, as a result, a higher voltage is applied to the stator, which allows you to change the speed and maintain more torque at a fixed constant speed.

The use of this electric motor as the main element of the actuator allows one designed node to ensure the creation of the required high torque at the output in the entire range of output speeds.

The actuator according to this invention has a motor control unit and a microprocessor control unit via an operator interface. The motor control unit contains all the circuits needed to control the motor and its protection.

The microprocessor is programmed to control the pulse-width modulation unit of the electric motor, which makes it possible to change the speed of the electric motor in the entire range of its speeds. A program is also sewn into the microprocessor, which allows you to set all operating parameters and issue an alarm signal when any setting is exceeded.

In one of the embodiments of the invention, the actuator has a control unit for the operator interface, containing circuits that allow you to set all the parameters both in place and remotely.

This control unit is connected to the microprocessor so that the operation of the actuator meets the requirements of the control system, the functional element of which is the actuator. According to these schemes, field bus operations are also possible through a matching interface.

Brief Description of the Drawings

FIG. 1 is a perspective view of an electrically controlled shutter actuator in accordance with one embodiment of the invention;

FIG. 2 is a section along the ΙΙ-ΙΙ axis of FIG. one;

FIG. 3 is a section along the ΙΙΙ-ΙΙΙ axis of FIG. one;

FIG. 4 is an enlarged vertical side view of the disconnecting cam and the latch, the drive fingers of the drive sleeve in engagement with the drive fingers of the rotor;

FIG. 5 is a view, as in FIG. 4, the drive fingers of the drive coupling in disengagement with the drive fingers of the rotor;

FIG. 6 is a block diagram of a first actuator operation control system according to FIG. 1-5;

FIG. 7 is a block diagram of a second actuator operation control system according to FIG. 1-5.

The ways of carrying out the invention

The actuator 10 of the embodiment of FIG. 1-5 consists of a housing 11 formed by a shaft compartment 12, an end compartment 13 closed by an end cover 14, a control compartment 15 closed by a control compartment cover 16, an auxiliary compartment 66 (see FIGS. 1 and 3) closed by a cover 67, and compartment sensor position 68 (see Fig. 1 and 3), closed by a cover 69. The shaft 17 is supported by a bearing 18 in the lower section of the housing 11 and a bearing 19 in the upper section of the housing 11.

The shaft 17 is driven by an electric motor 21, the stator 22 of which is mounted on the housing 11. The rotor 23 is articulated with the shaft 17 by means of a coupling 24.

The shaft 17, when the electric motor 21 is not working, for example, in case of power outages, can also be turned manually using the hand wheel 20.

The shaft compartment 12 is closed by the top cover 25 and the base of the drive 26. In the top cover 25 there is a hole in the center for the hub 28 of the hand wheel 20. Bearing 19a is mounted in the skirt 27 of the top cover 25. In the hub 28 there is a hole in the center for the shaft 17, as well as a bearing 19 between them. The hub 26 is sealed relative to the shaft 17 by the gland 29 and relative to the upper cover 25 by the gland 30. In this case, the hand wheel 20 is fixed on the hub 28 by a pin 31.

At the base of the actuator 26 there is a hole in the center for the end of the shaft 17 resting on the bearing 18. The base of the actuator 26 is sealed relative to the shaft 17 with an oil seal 34. The base of the actuator 26 is fixed to the housing 11 with screws (not shown).

In FIG. 3, 4 and 5 it is seen in detail that the motor 21 is located above the base of the drive 26, and the stator 22 is mounted on the skirt 35 of the housing 11. The stator 22 is mounted on the skirt 35 with screws 65. The rotor 23 is mounted to rotate on the shaft 17 in the bearing 36. The hub 37 of the rotor 23 has a plurality of protruding driver fingers 38 engaged with the carrier legs 39 on the driver sleeve 40, which is slidably mounted on the shaft 17 at the keys 41.

On the underside of the drive sleeve 40, there is a cam flange 43, onto which a cam 46 is attached, mounted on a separation shaft 47. The latch 44, which is mounted to rotate about an axis 45 on the cam 46, is biased by a spring 48 secured to the cam 46 by screws 49. Disengaging the shaft 47 is biased by the return spring 50. In FIG. 4, the actuator is shown in mechanical drive mode.

The disconnecting shaft 47 is rotated by the handle 54 (see FIG. 1) so that the carrier legs 39 can disengage from the carrier fingers 38, as shown in FIG. 4 for the case of driving the shaft 17 manually.

In FIG. 5, the actuator is shown in manual mode, the driving tabs 39 of the driving sleeve 40 are disengaged from the driving fingers 38 of the hub 37 of the rotor due to the contact of the shank 51 of the latch 44 with the shoulder 52 of the hub 37 of the rotor and the head 53 of the cam 46 with the shelf of the cam 43 of the driving sleeve 40.

The shaft position sensor disk 55 is mounted on the shaft 17 above the drive sleeve 40. A spring 56 between the disk 55 and the drive sleeve 40 pushes the drive sleeve 40 downward when the tail 51 of the latch 44 leaves the shoulder 52 when the rotor 23 rotates. The shaft 55 position sensor disk comes to the level of the head of the shaft position sensor 58, fixed in the hole of the housing 11 with screws 59.

In FIG. 3 shows the end compartment 13 with a terminal box 60 mounted on the housing 11 with screws 61. On the cover of the control compartment 16 there is a window 62 and switches / buttons 63.

In FIG. 6 and 7 show operation control and power indication systems for the actuator according to FIG. 1-5. The lines 100 supply power to the three-phase network to the power supply unit 101, which then feeds the inverter 102 through the line 103. From the inverter 102, power is supplied to the electric motor 21, which rotates the shaft 17.

In the absence of mains power in the case of manual mode, emergency power is supplied from the battery to the shaft position determination circuit 117, which allows fixing any rotation of the shaft (manually) in the absence of power. The battery switch 118 turns off the battery power, if rotation of the shaft is not detected during the specified period. Any rotation of the shaft manually automatically triggers the battery circuit through switch 118.

The microprocessor 104 receives the temperature signals of the electric motor 21 along the line 105, the position of the shaft 17 - along the line 106, the temperature of the inverter 102 - along the line 107 and the rotor speed - along the line 115.

All control functions are processed by microprocessor 104, which alternately delivers the signals of the required speed and torque settings to the programmable logic device (UPL) 113.

FIG. 6 - local control is carried out from the remote control 119, and remote - from block 111.

Before putting the device into operation from the remote control 119, the following parameters are set:

- access code,

- mode: OFF-LOCAL-

REMOTE CALIBRATION,

- reaching or holding,

- emergency close, open or stop,

- “close by torque” or “close by limit”,

- opening speed, rpm

- closing speed, rpm,

- setting of the opening torque, Nm,

- setting closing torque, Nm,

- the stroke limit is open (speed to a fully open position) 100%,

- the limit is closed (completely closed) 0%.

Local control is carried out through two buttons on the remote control - for the open and close functions - in the LOCAL or CALIBRATION modes.

The LCD 110 displays all indications and settings. When all these control parameters are entered, the device can work safely.

FIG. 7 - local control is carried out from the hand-held remote control (IR source) 108, and remote control from block 111.

Local indication 112 - there are two switches on the control input of the device, one selects control by OFF of the Local or Remote modes, and the other by STOP commands to close or open.

Before entering the device into operation from a hand-held remote control (IR source) 108, the following parameters are set:

- access code,

- reaching or holding,

- emergency close, open or stop,

- “close by torque” or “close by limit”,

- opening speed, rpm

- closing speed, rpm,

- setting of the opening torque, Nm,

- setting closing torque, Nm,

- the stroke limit is open (speed to a fully open position) 100%,

- the limit is closed (completely closed) 0%.

The LCD 110 displays all indications and settings. When all these control parameters are entered, the device can work safely.

Local indication (116 in Fig. 6 and 112 in Fig. 7) is three LEDs and a sixteen segment alphanumeric liquid crystal display (LCD) 110. The LEDs indicate CLOSED-ALARM-OPEN.

On the LCD 110 during an online survey, when the set values are requested, all settings are displayed and, in addition, the position in the process dynamics, together with the words closing or opening, depending on the direction, and open or closed at the end of each move.

The following alarm information is displayed:

- opening of the torque release (in abbreviated form (up to 16 segments)),

- closing the torque release,

- motor temperature,

- temperature of the electronic part,

- battery discharge.

Remote control and display 111 - standard control functions open - stop - close, as with local control. Indication:

- completely closed

- completely open

- remote installed

- the voltage is normal,

- refusal

- indication of position 4-20 mA.

Additionally, remote control is possible in cases

- analog position control (for devices for changing the position of valves),

- fieldbus connection for remote calibration, control and online polling.

All control parameters are stored by microprocessor 104.

Custom software has been developed to manage the working and procedural functions that must be implemented for the normal operation of the device in accordance with the specified functional requirements.

The programmable logic device (UPL) 113 is programmed to activate the power-on block when receiving a signal from the rotor position determination circuits via line 114. Then the power-on block activates an inverter that drives the electric motor 21. The duration of the power-on pulse is determined by the PWM signal received from microprocessor 104. The longer the signal lasts, the higher the speed of the electric motor.

The PWM speed signal is determined by the specified settings of the microprocessor 104 for the required opening and closing speeds.

Design and construction can be changed in detail without departing from the scope or scope of this invention.

Claims (12)

CLAIM 1. Electrically controlled actuator of the gate or valve with the moment of moving the drive rod of the valve or gate more than 10 Nm and consisting of (I) a hollow body, (II) a drive shaft that is rotatably mounted in the body and at which one end protrudes from the body for joints with a drive stem of the gate or damper, (III) an electric motor with a rotor and a stator, capable of creating a torque of more than 10 Nm and installed in the housing, with a rotor coaxially mounted on the shaft, and a stator fixedly mounted inside enclosures, (IV) motor control devices. 2. The actuator according to claim 1, wherein the electric motor is a variable-speed electric motor with a permanent magnet and a constant torque. 3. The actuator according to claim 2, wherein the electric motor is a high-torque DC motor controlled by pulse-width modulation (PWM). 4. The actuator according to claim 3, characterized in that the electric motor provides a variable speed at the output of the drive shaft in a given range of speeds. 5. The actuator according to claim 3, wherein the electric motor provides a constant torque in a predetermined speed range. 6. The actuator according to claim 1, wherein the rotor is mounted for rotation on the drive shaft and in the actuator there is a coupling for coupling the rotor and the drive shaft. 7. The actuator according to claim 6, characterized in that the coupling has a drive sleeve installed with the possibility of sliding over the drive shaft, but without the possibility of rotation relative to the drive shaft, the drive fingers on the drive sleeve, the drive fingers on the rotor and the spring device for the usual displacement of the drive sleeve in the direction of the rotor, so that the driver fingers are engaged. 8. The actuator according to claim 7, consisting of a cam device for connecting the drive sleeve and pulling the drive sleeve from the rotor, counteracting the spring device to disengage the driver fingers. 9. The actuator of claim 8, wherein the second end of the drive shaft is connected to a handwheel for turning the drive shaft when the driver pins are disengaged. 10. The actuator according to claim 1, wherein the motor control device is an electric motor control unit consisting of motor control and protection circuits and an operator interface control unit for setting operating parameters of the actuator. 11. The actuator of claim 10, wherein the control device contains a microprocessor programmed to be able to set operating parameters and issue alarms when any setpoint is exceeded. 12. The actuator according to claim 10, characterized in that the control unit via the operator interface allows setting the operating parameters on site or remotely.