CN-121630682-B - Two-stage compression high-vacuum small dry vacuum pump

CN121630682BCN 121630682 BCN121630682 BCN 121630682BCN-121630682-B

Abstract

The application discloses a two-stage compression high-vacuum small dry vacuum pump which comprises a vacuum pump body, a multi-transmission frequency converter, an acquisition assembly and a controller, wherein the vacuum pump body comprises two stages of compression cylinders which are connected in series, meshed male and female rotors are rotatably arranged in the compression cylinders, a motor for driving the male and female rotors is arranged in the compression cylinders, the motor is simultaneously connected with the two stages of compression cylinders, the acquisition assembly comprises a first sensor for acquiring actual exhaust pressure in real time and a second sensor for acquiring actual interstage pressure in real time, and the controller is connected with the transmission frequency converter and the acquisition assembly and comprises a first sub-control module and a second sub-control module. The application solves the problems that the existing high-vacuum small-sized dry vacuum pump does not synchronously control two-stage compression and has risk hidden trouble of unbalanced inter-stage rotating speed.

Inventors

CHENG GUANGMING
GAO BAOHUA
LI CUIPING
LI QINGFEI

Assignees

上海格什特螺杆科技有限公司

Dates

Publication Date: 20260508
Application Date: 20251210

Claims (1)

1. A two-stage compression high vacuum miniature dry vacuum pump, comprising: The vacuum pump body comprises two stages of compression cylinders which are connected in series, meshed male and female rotors are rotatably arranged in the compression cylinders, and motors for driving the male and female rotors are arranged in the compression cylinders; The multi-transmission frequency converter is simultaneously connected with the motors of the two-stage compression cylinders; the acquisition assembly comprises a first sensor for acquiring actual exhaust pressure in real time and a second sensor for acquiring actual interstage pressure in real time; A controller coupled to the drive frequency converter and the acquisition assembly, the controller comprising a first sub-control module and a second sub-control module, the first sub-control module increasing a first shaft frequency of the multiple drive frequency converter to increase a motor speed of a first shaft driven primary compression cylinder of the multiple drive frequency converter such that an actual exhaust pressure increases, the first sub-control module decreasing the first shaft frequency by a given increase after the first differential pressure decreases such that the motor speed of the primary compression cylinder increases by a decrease in magnitude such that an actual exhaust pressure increases by a decrease in magnitude, such that the first differential pressure is zeroed, and increasing a second shaft frequency of the multiple drive frequency converter such that a second shaft driven secondary compression cylinder of the multiple drive frequency converter increases such that the actual differential pressure is coordinated with the second differential pressure, such that the first differential pressure is zeroed; The motor is a parallel shaft double-rotor motor, and double rotors of the parallel shaft double-rotor motor are respectively and coaxially arranged with the male rotor and the female rotor; the motor is adhered with a radiator through heat-conducting glue; the radiator is an extruded radiator.

Description

Two-stage compression high-vacuum small dry vacuum pump Technical Field The invention relates to the technical field of vacuum pumps, in particular to a two-stage compression high-vacuum small dry vacuum pump. Background The small dry vacuum pump generally adopts multi-stage compression for realizing high efficiency, high vacuum degree and stable operation, and aims to improve the ultimate vacuum degree. Because the compression ratio of the single-stage compression vacuum pump is limited, the multistage serial compression vacuum pump can improve the final vacuum degree, and meanwhile, the multistage compression vacuum pump is matched with the gas flow through the volume changes of different stages, so that the efficiency loss caused by gas back leakage of the single-stage compression under low pressure is avoided. The single-stage high compression ratio can lead to the rapid rise of the gas temperature and possibly damage the sealing material, the multistage compression can gradually reduce the gas temperature, the influence of thermal stress on the pump body is reduced, the energy consumption can be reduced by 20-30% compared with the single-stage adiabatic compression, the overhigh instantaneous power of the single-stage motor is avoided, and the service lives of the bearing and the transmission part are prolonged. In a word, the core goal of adopting multistage compression in the high-vacuum small-sized dry vacuum pump is to balance vacuum degree, efficiency and reliability, the essence of the high-vacuum small-sized dry vacuum pump is that the single-stage physical limit is broken through by multistage compression, meanwhile, the heat load and energy consumption are reduced, the smaller the number of stages is, the better the number of stages is on the premise of meeting the requirement, and the two-stage compression is usually adopted in most. The electric system of the small-sized dry vacuum pump with high vacuum degree generally comprises a control system, a driving system and an executing system. The standard controller of the control system integrates control process logic and pre-alarm protection measures, and monitors the running state of the vacuum pump in real time to control the driving system to control the running of the motor of the execution system. The current two-stage compression high-vacuum small dry vacuum pump control system is a standard controller, the driving system is two frequency converters, the execution system is two permanent magnet synchronous motors, and the system is simple and practical, and has the practical defects: The permanent magnet synchronous motor of the execution system has a large volume, so that the vacuum pump with the compact structure slightly expands, and heat conduction is realized by utilizing the metal material of the motor shell, so that the heat dissipation efficiency is low, and the high-load operation is easy to overheat; the driving system directly adopts two sets of frequency converters, which is simple and convenient, but lacks integration consideration; The control system is based on a single-stage compression standard controller, a motor for controlling two-stage compression by one frequency converter is added, two sets of frequency converters also adopt a sequential start-stop control mode, the working requirement of the whole machine is basically met, but the two-stage compression is not synchronously controlled, so that the control scheme is not perfect, and the risk hidden danger of unbalance of the inter-stage rotating speed exists. Disclosure of Invention In order to overcome the defects existing in the prior art, the two-stage compression high-vacuum small dry vacuum pump is provided, so that the problem that the existing high-vacuum small dry vacuum pump does not synchronously control two-stage compression and has risk hidden trouble of unbalanced inter-stage rotating speed is solved. To achieve the above object, there is provided a two-stage compression high vacuum small dry vacuum pump comprising: The vacuum pump body comprises two stages of compression cylinders which are connected in series, meshed male and female rotors are rotatably arranged in the compression cylinders, and motors for driving the male and female rotors are arranged in the compression cylinders; The multi-transmission frequency converter is simultaneously connected with the motors of the two-stage compression cylinders; the acquisition assembly comprises a first sensor for acquiring actual exhaust pressure in real time and a second sensor for acquiring actual interstage pressure in real time; And the controller is connected with the transmission frequency converter and the acquisition component, and comprises a first sub-control module and a second sub-control module, wherein the first sub-control module increases the first shaft frequency of the multi-transmission frequency converter to increase the motor rotation speed of a first shaft driven one-stage compress