CN216198960U

CN216198960U - Totally-enclosed direct-current frequency conversion dry-type scroll vacuum pump

Info

Publication number: CN216198960U
Application number: CN202122594863.4U
Authority: CN
Inventors: 赵洪健; 张文卓; 陈建国; 王邦国; 何荣国
Original assignee: Dalian University
Current assignee: Dalian University
Priority date: 2021-10-27
Filing date: 2021-10-27
Publication date: 2022-04-05
Anticipated expiration: 2031-10-27

Abstract

The utility model discloses a totally-enclosed direct-current variable-frequency dry-type scroll vacuum pump, and belongs to the technical field of vacuum pumps. Including drive main shaft pivoted motor, motor and main shaft all are located the casing, and the base is connected to the chassis bottom, are equipped with cooling mechanism on the main shaft, and the eccentric shaft is connected at the main shaft top, and the eccentric shaft moves the vortex dish through self-lubricating bearing connection, move the vortex dish and pass through floating bearing and main tributary branch and prop sliding connection, the casing is connected to the main tributary branch bottom, and the main tributary branch top is connected and is decided the vortex dish, decides the vortex dish middle part and is equipped with the gas vent, gas vent department is equipped with one-way exhaust mechanism. The utility model has the beneficial effects that: the fully-closed structure is adopted, so that the vacuum pump can meet more and more complex environments, and simultaneously, the vibration and noise generated in the working engineering of the vortex vacuum pump can be reduced. A variable-frequency air cooling mechanism is adopted to dissipate heat of a main shaft of a main heat-generating component of the vacuum pump and the movable scroll plate.

Description

Totally-enclosed direct-current frequency conversion dry-type scroll vacuum pump

Technical Field

The utility model relates to a totally-enclosed direct-current variable-frequency dry-type scroll vacuum pump, and belongs to the technical field of vacuum pumps.

Background

The working cavity of the scroll vacuum pump is formed by the meshing installation of a pair of scroll disks with the same structure and 180 degrees of phase difference. In the working process, the crankshaft drives the movable scroll plate to rotate around the main shaft under a certain eccentricity. Meanwhile, the anti-rotation mechanism ensures the phase difference between the movable scroll and the fixed scroll, and the crescent volume formed by the mutual meshing of the movable scroll and the fixed scroll generates periodic change, thereby realizing the air suction, compression and exhaust circulation of the scroll vacuum pump and achieving the purpose of forcibly conveying gas.

The main moving part of the scroll vacuum pump is only one movable scroll plate, so that the power transmission is simple, and the moving part in the pump and the pump cavity almost have no friction, so that the scroll vacuum pump has the advantages of stable operation, high volume efficiency, low vibration noise, high reliability and the like. Based on this, the scroll vacuum pump has been widely accepted in the industries of semiconductors, scientific instruments, medical equipment and the like.

In recent years, due to the limitation of application occasions, the traditional vacuum system is difficult to meet the requirements of cleanness, oil free and corrosion resistance, and the dry type scroll vacuum pump is vigorously developed and popularized. In the working process of the dry type scroll vacuum pump, no metal is contacted with metal in the pump cavity, and no friction exists in the pumping cavity element, so that the dry type scroll vacuum pump has the advantages of stable operation, low energy consumption, high reliability, compact structure and long service life.

With the rapid development of science and technology in China, the requirements of high and new technology products on vacuum degree and vibration noise performance are increasingly strict. For example, during the pharmaceutical process, too high a vacuum level may cause the drug to react, fail, or even deteriorate. In the processing process of semiconductor materials, the vacuum degree can seriously affect the quality of products, the materials can be oxidized due to the overhigh vacuum degree, and the products can be damaged due to the overlow vacuum degree. Most of the current dry-type scroll vacuum pumps are fixed frequency, the vacuum degree of the system can only be adjusted through a ball valve, electric energy is wasted, noise is large, and the development direction of green energy conservation is not met. More importantly, the vacuum pump is difficult to realize accurate control of the vacuum degree.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects in the prior art, the utility model aims to provide a totally-enclosed direct-current variable-frequency dry-type scroll vacuum pump which saves energy and realizes the adjustment of vacuum degree.

The technical scheme of the utility model is as follows: a totally-enclosed direct-current frequency conversion dry-type scroll vacuum pump comprises a motor for driving a main shaft to rotate, wherein the motor and the main shaft are both positioned in a machine shell, the bottom of the machine shell is connected with a base, the main shaft is provided with a cooling mechanism, the top of the main shaft is connected with an eccentric shaft, the eccentric shaft is connected with a movable scroll plate through a self-lubricating bearing, the movable scroll plate is connected with the main support in a sliding way through the floating bearing, the bottom of the main support is connected with the casing, the top of the main support is connected with the fixed scroll plate, the middle part of the fixed scroll plate is provided with an exhaust port, the exhaust port department is equipped with one-way exhaust mechanism, decides the vortex dish side top and is equipped with the air inlet, moves the tooth a top and the sealed swing joint of deciding the vortex dish, decides the tooth b bottom of vortex dish and moves the sealed swing joint of vortex dish, is fixed with on the main tributary and prevents the rotation spacer pin, prevent that rotation spacer pin top extends to in the bottom recess of moving the vortex dish.

The cooling mechanism is a turbofan.

The one-way exhaust mechanism comprises a reed valve block located at the exhaust port, one end of the reed valve block is arranged at the top of the exhaust port side through a fastening bolt, a limiter is arranged at the top of the reed valve block, and the end part of the limiter is fixed through the fastening bolt.

The motor is a brushless DC motor, the brushless DC motor is connected with a power supply through a controller, the controller is connected with a processor, a vacuum degree standard value is preset in the processor, the processor is connected with a pressure sensor, and the detection end of the pressure sensor is located at an air inlet.

And a stator bushing made of nitrile rubber is arranged outside the motor.

The fixed scroll is provided with a sealing groove, a sealing strip is installed in the sealing groove, and the sealing strip is made of stainless steel-butyronitrile materials with self-lubricating performance.

Based on the technical means, the utility model can obtain the following gain effects: (1) this frequency conversion vortex vacuum pump adopts totally closed structure, makes the vacuum pump can satisfy more, more complicated environment, can reduce vibration and the noise that produces in the work engineering of vortex vacuum pump simultaneously. (2) The main shaft of the vacuum pump, the movable scroll plate, the main support and other connecting parts are all bearings with self-lubricating performance, and the inner lining is made of Polytetrafluoroethylene (PTFE) material. The bearing can effectively reduce the friction between the main shaft and each component in the motion process, improve the wear resistance and ensure the reliability when the oil is not available. (3) When the main shaft rotates, the movable scroll is driven to generate radial disturbance, the floating bearing can balance the disturbance, the leakage of compressed gas generated by axial and radial gaps is reduced, and the backflow of the gas is reduced. (4) A variable-frequency air cooling mechanism is adopted to dissipate heat of a main shaft of a main heat-generating component of the vacuum pump and the movable scroll plate. The turbofan rotates along with the main shaft, reduces the temperature of the main shaft and the movable scroll plate, and prolongs the service life of the movable scroll plate and the main shaft. Under the condition of high rotation frequency of the vacuum pump, the friction between parts is strong and the temperature is high due to the fact that the rotation speed of the main shaft is high. The rotating speeds of the fan and the main shaft are consistent, and the cooling capacity is obviously enhanced.

Drawings

FIG. 1 is a block diagram of the present invention;

FIG. 2 is a structural view of the exhaust mechanism of the present invention;

FIG. 3 is an electrical control schematic of the present invention;

FIG. 4 is a diagram of an orbiting scroll structure;

fig. 5 is a structural view of a turbofan.

The reference numbers in the figures are as follows: 1. the air exhaust mechanism comprises 1.1 parts of reed valve plates, 1.2 parts of fastening bolts, 1.3 parts of a limiting stopper, 2 parts of a fixed scroll, 3 parts of a movable scroll, 4 parts of a main support, 5 parts of a shell, 6 parts of a cooling mechanism, 7 parts of a base, 8 parts of a main shaft, 9 parts of a stator bushing, 10 parts of a motor, 11 parts of a self-lubricating bearing, 12 parts of a floating bearing, 13 parts of an anti-rotation limiting pin, 14 parts of a pressure sensor, 15 parts of an air inlet.

Detailed Description

The utility model will be further illustrated with reference to the following specific examples shown in figures 1 to 5:

a totally-enclosed direct-current frequency conversion dry-type scroll vacuum pump comprises a motor 10 for driving a main shaft 8 to rotate, wherein the motor 10 and the main shaft 8 are both positioned in a casing 5, the bottom of the casing 5 is connected with a base 7, a turbofan is arranged on the main shaft 8 and rotates synchronously with the main shaft, the temperature is reduced in the system operation process, the top of the main shaft 8 is connected with an eccentric shaft, the eccentric shaft is connected with a movable scroll 3 through a self-lubricating bearing 11, a lining of the self-lubricating bearing 11 is made of Polytetrafluoroethylene (PTFE) material, the bearing can effectively reduce the friction between the main shaft and each component in the main shaft movement process, the wear resistance is improved, the reliability in oil-free operation is ensured, the movable scroll 3 is in sliding connection with a main support 4 through a floating bearing 12, the floating bearing 12 provides reverse thrust for the movable scroll 3 in the operation process, the bottom of the main support 4 is connected with the casing 5, the top of the main support 4 is connected with the fixed scroll 2, the middle part of the fixed scroll 2 is provided with an exhaust port, the exhaust port is provided with a one-way exhaust mechanism 1, the one-way exhaust mechanism 1 comprises a reed valve block 1.1 positioned at the exhaust port, one end of the reed valve block 1.1 is arranged at the top of the exhaust port side through a fastening bolt 1.2, the top of the reed valve block 1.1 is provided with a limiter 1.3, the end part of the limiter 1.3 is fixed through the fastening bolt 1.2, the limiter 1.3 can prevent the reed valve block 1.1 from overtravel, the reed valve block is made of stainless steel and has good rigidity, the fastening bolt 1.2 is fixed to ensure that the reed valve block 1.1 can exhaust well and can be tightly closed after exhaust, the air return phenomenon is prevented, the top of the side of the fixed scroll 2 is provided with an air inlet 15, the top of the tooth a of the movable scroll 3 is in sealing movable connection with the fixed scroll 2, the bottom of the tooth b of the fixed scroll 2 is in sealing movable connection with the movable scroll 3, an anti-rotation limiting pin 13 is fixed on the main support 4, the top of the anti-rotation limiting pin 13 extends into a groove at the bottom of the movable scroll 3, and the anti-rotation limiting pin 13 is matched with the groove at the bottom of the movable scroll 3, so that the movable scroll 3 can only make revolution translation along with the eccentric shaft in a plane.

The motor 10 is a brushless DC motor, the brushless DC motor is connected with a power supply through a controller, the controller is connected with a processor, a vacuum degree standard value is preset in the processor, the processor is connected with a pressure sensor 14, and the detection end of the pressure sensor 14 is positioned at an air inlet 15. A pressure sensor 14 at an air inlet 15 detects the internal pressure of the system, data are transmitted to a processor, the processor adjusts the pulse duty ratio through a controller according to the vacuum degree requirement set by a user, the rotation frequency of the motor is changed to realize accurate adjustment of the vacuum degree of a pumped area, the rotation frequency of the motor is changed by changing voltage, and when the voltage is increased, the rotation speed of the motor is increased; when the voltage decreases, the motor speed decreases. The controller can change the voltage of the motor by adjusting the duty ratio of the pulse width modulation signal, thereby realizing the adjustment of the rotation frequency of the motor. According to the vacuum degree requirement set by the user, the controller outputs a voltage pulse signal to drive the motor to rotate, and a pressure sensor probe at the air inlet senses the pressure (P) of the working area_a). Degree of vacuum (V)_r) Obtained according to the following formula:

P_v＝P_atm-P_a

P_vis the relative pressure, P_atmIs atmospheric pressure, P_aIs a work areaThe pressure of (a).

And a stator bushing 9 made of nitrile rubber is arranged outside the motor 10. The bushing has excellent heat resistance and wear resistance. The motor can still be protected at the temperature of 90 ℃, and the noise of the motor under the high-frequency operation is reduced.

The fixed scroll 2 is provided with a sealing groove, a sealing strip is installed in the sealing groove, and the sealing strip is made of stainless steel-butyronitrile materials with self-lubricating performance. The sealing strip has good strength and lubricating performance. The leakage of compressed gas is prevented, and the friction loss between the movable scroll and the fixed scroll is reduced, thereby improving the volumetric efficiency of the vacuum pump.

Under the action of the anti-rotation mechanism, the movable vortex plate revolves around the main shaft in a plane. The gas enters a crescent closed area between the movable vortex plate and the fixed vortex plate from the gas inlet. The contact point between the movable and the fixed scroll plates moves along the curved surface of the scroll so as to realize the suction, compression and exhaust of the vacuum pump. The vacuum degree is gradually increased to be close to the set vacuum degree requirement. The controller reduces the duty ratio of the pulse, reduces the rotating speed of the driving motor and enables the driving motor to stably run, and the vacuum degree of the working area is stabilized at the vacuum degree required by a user. The main shaft adopted by the vacuum pump is a motor section and an eccentric shaft section which are integrally formed. The main shaft has excellent strength and rigidity, and ensures that the vacuum pump has good reliability in the long-term working process.

When the pressure inside the scroll pump is lower than the atmospheric pressure, the exhaust mechanism can eliminate the phenomena of insufficient compression ratio and air return. The tail part of a reed valve plate 1.1 of the exhaust mechanism is arranged on the end surface of the fixed scroll through a fastening bolt 1.2. The head of the valve plate is circular, and the diameter of the valve plate is 2mm larger than the size of the exhaust hole. In the exhaust process, the reed valve block 1.1 is deformed and opened by the impact of gas, and the limiter 1.3 protects the reed valve block 1.1 from being damaged by the impact of gas. The reed valve plate 1.1 is made of stainless steel and has good rigidity. The reed valve plate can exhaust well and can be tightly closed after exhausting by controlling the opening height of the limiter, so that the reed valve plate can exhaust fully and can prevent the air return phenomenon.

The wind power of the turbine fan blades is strong, the propagation distance is long, and the heat dissipation effect is better. The turbine fan blades are arranged on the main shaft through a shaft end retainer ring, a bearing and screws and rotate along with the main shaft, so that the cooling and the cooling of the movable scroll plate of the main heat generating component of the vacuum pump are realized. Under the high rotation frequency of the vacuum pump, the friction between parts is strong, and the temperature is high. The fan rotates along with the main shaft, so that the rotating speed of the fan is obviously improved, the cooling capacity is obviously enhanced, and the reliability of parts such as the main shaft, the movable scroll plate and the like is improved. Under the low-frequency rotation frequency, the friction between the movable scroll plate of the vacuum pump and each component is relatively weak, the heat of the movable scroll plate is not high, the heat dissipation function is met, and meanwhile, the energy loss of the fan can be effectively reduced, and the energy consumption is reduced.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A totally-enclosed direct-current frequency conversion dry-type scroll vacuum pump is characterized by comprising a motor (10) for driving a main shaft (8) to rotate, wherein the motor (10) and the main shaft (8) are both positioned in a casing (5), the bottom of the casing (5) is connected with a base (7), the main shaft (8) is provided with a cooling mechanism (6), the top of the main shaft (8) is connected with an eccentric shaft, the eccentric shaft is connected with a movable scroll (3) through a self-lubricating bearing (11), the movable scroll (3) is in sliding connection with a main support (4) through a floating bearing (12), the bottom of the main support (4) is connected with the casing (5), the top of the main support (4) is connected with a fixed scroll (2), the middle of the fixed scroll (2) is provided with an exhaust port, the exhaust port is provided with a one-way exhaust mechanism (1), the top of the side of the fixed scroll (2) is provided with an air inlet (15), and the top of a tooth a of the movable scroll (3) is in sealing connection with the fixed scroll (2), the bottom of the tooth b of the fixed scroll (2) is movably connected with the movable scroll (3) in a sealing manner, an anti-rotation limiting pin (13) is fixed on the main support (4), and the top of the anti-rotation limiting pin (13) extends into a groove at the bottom of the movable scroll (3).

2. A totally enclosed direct current variable frequency dry scroll vacuum pump according to claim 1, wherein the cooling down mechanism (6) is a turbofan.

3. The totally-enclosed direct-current frequency conversion dry scroll vacuum pump according to claim 1, wherein the one-way exhaust mechanism (1) comprises a reed valve block (1.1) located at the exhaust port, one end of the reed valve block (1.1) is arranged at the top of the exhaust port side through a fastening bolt (1.2), a limiter (1.3) is arranged at the top of the reed valve block (1.1), and the end of the limiter (1.3) is fixed through the fastening bolt (1.2).

4. A totally enclosed direct current frequency conversion dry type scroll vacuum pump according to claim 1, wherein the motor (10) is a dc brushless motor, the dc brushless motor is connected with a power supply through a controller, the controller is connected with a processor, a vacuum standard value is preset in the processor, the processor is connected with a pressure sensor (14), and a detection end of the pressure sensor (14) is located at the air inlet (15).

5. A totally enclosed direct current variable frequency dry scroll vacuum pump according to claim 1, wherein a stator bushing (9) of nitrile rubber is provided outside the motor (10).

6. A totally-enclosed direct-current frequency conversion dry-type scroll vacuum pump as claimed in claim 1, wherein the fixed scroll (2) is provided with a sealing groove, a sealing strip is installed in the sealing groove, and the sealing strip is made of stainless steel-butyronitrile material with self-lubricating property.