CN2083671U

CN2083671U - Differential electric carrying device

Info

Publication number: CN2083671U
Application number: CN 90216805
Authority: CN
Inventors: 钱强华
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-07-21
Filing date: 1990-07-21
Publication date: 1991-08-28

Abstract

The utility model discloses an electric carrying device used for gas and liquid control system, adopting a differential speed change mechanism. An execution signal from a servo amplifier is compared with a control signal, and then two direct current torque motors can respectively drive two contrarotational driving gears to output the difference value of the signals via planet gears. Due to the adoption of a differential drive mechanism and the direct current torque motors, the utility model has simple and compact mechanical structure, the size of the signals can be controlled, and speed can be adjusted automatically. The utility model is suitable for controlling the water supplying flowrate and the ventilative flowrate of power stations or large boilers.

Description

Differential electric carrying device

The utility model relates to the actuator of gas, liquid control system, particularly electric actuator.

At present, DDZ series electric actuator is generally used in the flow control of be used for the feedwater of power station or large-scale boiler for domestic, ventilating.This kind final controlling element is because motor is a synchronous machine, therefore, can only do a kind of running of speed or stop (speed ratio on reducing gear is decided) and can not change its rotating speed with the size of signal between signal has or not, thereby cause overshoot; Even the employing frequency control of motor speed, when rotating speed was lower than below 1 rev/min, motor just can not rotate, and time constant is big, and the blind area is big, and sensitivity is lower, caused the stove fluctuating temperature bigger.

The purpose of this utility model: provide a kind of and have and the corresponding governing speed of control signal for overcoming above-mentioned deficiency, promptly water level rises and can turn down the electric actuator of water supply valve gradually, to reduce fluctuating temperature, controlled device is operated in efficiently under the situation.

The utility model is realized as follows:

1. the controlled signal of servoamplifier divides two passes that its difference is promoted two DC servo motors runnings respectively with the execution signal and after set value signal is compared, and makes driving gear obtain kinetic energy by driving gear;

2. two～three pairs of planetary pinions can be arranged on the planet carrier of electric actuator, arbitrary planetary pinion is all intermeshed, and each planetary pinion respectively with a driving gear engagement, forms a differential rotating mechanism, make it to export difference at output shaft.

The utility model is owing to adopt differential transmission mechanism and DC torque actuating motor, and mechanical structure is simply compact, and Transmitted chains is short, and inertia is little, helps regulating the speed automatically by the control signal size.

The utility model is described in further detail below in conjunction with embodiment:

Fig. 1 is a differential type electric actuator structural representation.

1,2 is driving gear; 1 ', 2 ' be driving gear; 3,4 ' be a pair of planetary pinion; 4,3 ' be that another is to planetary pinion; 5 is output shaft; 6 is planet carrier; 7,8 is DC servo motor; 9 is handwheel.

Fig. 2 is a differential type electric actuator profile of tooth top view.

Fig. 3 is a differential type electric actuator schematic diagram.

As figure, the 7th, by the DC torque actuating motor that switching signal drove of controll plant, through driving gear 1 and the driving gear 1 that links to each other ', obtain kinetic energy from motor, and rotate with dextrad; The 8th, carry out the DC torque actuating motor that switching signal drove of control, through driving gear 2 and the driving gear 2 that links to each other ' obtain kinetic energy from motor, and with left-handed rotation; 3,4 ' and 4,3 ' be two pairs of planetary pinions, be contained on the planet carrier 6 that connects together with output shaft 5; Arbitrary to planetary pinion, as: 3 ', 4 intermesh, and the differential type speed changer is formed with driving gear 2 ' (or 1 ') engagement respectively in planetary pinion 3 ' (or 4).Its working principle is as follows:

In the schematic diagram: gear 1 ' be dextrorotation, 4 is left-handed by drive, 2 ' left-handed, 3 ' quilt is driven dextrorotation.Like this, 4 and 3 ' be counterrotating, if driving gear 1 ' equal with 2 ' rotating speed, then 4 revolutions cross how many teeth promptly are inverted 3 ' offset, therefore, 3 ', 4 two gears only understand axial rotation, as the planetary pinion fulcrum 6 because of there not being 4 active force, so output shaft 5 can not rotate; Only become when changeing fast greatly because of signal at 1 ' driving gear, 4 are driven and are also changeed fast, and 3 ' change fast because of 2 ' not, so 4 numbers of teeth that turn over 3 ' can not deduct fully, this remainder makes 4 to become active, drive 3 ' 2 ' on turn right; Bearing 6 of 4 fulcrums is subjected to active force and makes 5 to turn right; If 2 ' faster than 1 ', then make 5 to anticlockwise.5 rotating speed is decided by 1 ' and 2 ' speed discrepancy.

Fig. 4 is the servoamplifier skeleton diagram.

Among the figure, controlled, carry out, three signals of definite value are made description below: in acting on boiler liquid level control, controlled is boiler liquid level, claims liquid level signal, what carry out liquid level control is modulating valve, so carry out signal valve position signal, set value signal is a specified altitude to boiler liquid level to be arranged, and is framing signal.Its controlled signal is with after set value signal is compared, with its difference pushing motor; Carry out signal with its difference is promoted another motor after controlled signal is compared.Be that example is explained as follows now with a passage:

With the differential transformer is position transducer, its primary winding is encouraged by the oscillator in the NE5520 intergrated circuit, secondary is sent 5520 accent that are situated between back to, the row operation of going forward side by side is amplified and output 0-10 milliampere level electric current, as want display position, can be by the NE5535 intergrated circuit from 5520 input signals, indicate the microampere meter of position scale with driving, directly demonstration (also can show with numeral after the A/D conversion) is imported 5G33 differential amplifier from 5520 output and set value signal (or controlled signal) ratio of components than the networking with milliampere level signal, because of differential amplifier has bipolarity output, so energy driving power amplifier reaches the two-way function that promptly increases and decreases the DC servo motor driving current from former basis and makes electrical motor gearshift.

Claims

1, the planetary electric actuator of a kind of employing, has motor, planetary pinion and servoamplifier, it is characterized in that adopting differential speed change, the Twin channel servoamplifier, the driving gear (1 ') of two DC servo motors (8), two counterrotatings of (7) transmission and (2 '), and press to carry out in the servoamplifier with two signalling channels of control and rotate; Planet carrier (6) a pair of planetary pinion of taking up an official post intermeshes, each planetary pinion respectively with a driving gear engagement.

2, electric actuator as claimed in claim 1 is characterized in that adopting the DC torque actuating motor.