CN112610461A

CN112610461A - Electric diaphragm pump with self-protection function

Info

Publication number: CN112610461A
Application number: CN202011425869.2A
Authority: CN
Inventors: 王圣双
Original assignee: Jiashan Frontier Machinery Co ltd
Current assignee: Jiashan Frontier Machinery Co ltd
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2021-04-06
Anticipated expiration: 2040-12-09
Also published as: CN112610461B

Abstract

An electric diaphragm pump with self-protecting function is composed of motor, torque regulator and diaphragm pump. The torque adjusting mechanism comprises a shell, an end cover, an air pressure linkage mechanism, an air pressure adjusting assembly and a pressure adjusting valve. The pneumatic linkage mechanism comprises a driving assembly, a driven shaft, a first sealing cavity and a second sealing cavity. The drive assembly includes a guide shaft, a flat key, and a burr shaft. The grinding disc shaft is arranged on the guide shaft in a sliding mode through the flat key and is arranged at intervals with the driven shaft. The grinding disc shaft penetrates through the first sealing cavity and extends into the second sealing cavity. When the torque loaded by the driven shaft exceeds the rated torque, gas is input into the second sealing cavity through the air pressure adjusting mechanism, so that the grinding disc shaft is pushed to move towards the direction of the guide shaft, the grinding disc shaft is separated from the driven shaft, the motor idles, and the purpose of protecting the motor and the diaphragm pump is achieved.

Description

Electric diaphragm pump with self-protection function

Technical Field

The invention relates to the technical field of diaphragm pumps, in particular to an electric diaphragm pump with a self-protection function.

Background

The electric diaphragm pump is a novel pump, and can be applied to industries such as petrifaction, ceramics, metallurgy and the like due to breakthrough development on the material of the diaphragm. Its advantages are no need of irrigation and water, and high self-sucking power. The working principle is that an upper one-way ball valve and a lower one-way ball valve are arranged in a left pump cavity and a right pump cavity of the diaphragm pump, a motor drives diaphragms on plungers at the left end and the right end of the diaphragm pump to reciprocate, the four one-way ball valves are forced to be alternately opened and closed, the volume in the working cavity is changed, and therefore liquid is continuously sucked and discharged.

In the electric diaphragm pump in the prior art, the driven shaft of the motor is directly connected with the diaphragm pump, so that the diaphragm pump is driven to work. However, when the pressure inside the diaphragm pump is too high, the bearing of the motor may bear a large load, and when the load is too high, the motor may be damaged quickly. The method adopted at present is to damage the bearing of the motor and replace the bearing in time, thereby protecting the motor and the diaphragm pump. However, the cost is high, and the work is stopped to disassemble and replace the workpiece, which affects the working efficiency.

Disclosure of Invention

In view of the above, the present invention provides an electric diaphragm pump with a self-protection function to solve the above technical problems.

An electric diaphragm pump with self-protecting function includes a torque adjusting mechanism. The torque adjusting mechanism comprises a shell, an air pressure linkage mechanism arranged in the shell and an air pressure adjusting assembly arranged on the shell. The pneumatic linkage mechanism comprises a driving assembly arranged on the motor, a driven shaft arranged at an interval with the driving assembly, a first sealing cavity arranged on the driving assembly, and a second sealing cavity arranged on the driven shaft. The driving assembly comprises a guide shaft arranged in the shell, two flat keys respectively arranged on two sides of the guide shaft, and a grinding disc shaft arranged on the two flat keys in a sliding manner. The guide shaft drives the grinding disc shaft to rotate. The two flat keys are respectively arranged on two sides of one end of the guide shaft and are positioned between the guide shaft and the grinding disc shaft, one side surface of each flat key is tightly attached to the outer side surface of the guide shaft, and the other side surface of the opposite side is tightly attached to the inner side surface of the grinding disc shaft. One end of the grinding disc shaft is arranged on the two flat keys in a sliding mode and is located in the first sealing cavity, and the end face of the other end of the grinding disc shaft is a plane end and penetrates through the first sealing cavity to extend into the second sealing cavity. The end face of one end of the driven shaft is a plane end and is arranged at an interval with the plane end of the grinding disc shaft, and the other end of the driven shaft extends out of the shell. And gas enters the first sealing cavity or the second sealing cavity through the air pressure adjusting mechanism and drives the grinding disc shaft to make reciprocating translation so as to enable the grinding disc shaft to be in contact with or disconnected from the driven shaft.

Further, the electric diaphragm pump having the self-protection function further includes a motor that drives the torque adjusting mechanism, and a diaphragm pump provided on the torque adjusting mechanism.

Furthermore, the torque adjusting mechanism further comprises an end cover arranged at one end of the shell, and the driven shaft penetrates through the end cover.

Furthermore, the air pressure adjusting mechanism comprises a first air pipe arranged on the first sealed cavity and connected with the first sealed cavity and the barrel, a second air pipe arranged on the second sealed cavity and communicated with the second sealed cavity, an electromagnetic valve arranged on the first air pipe and the second air pipe, and a temperature sensor arranged outside the shell.

Further, the temperature sensor is used for detecting the temperature of the joint of the driven shaft and the grinding disc shaft.

Further, the torque adjusting mechanism further comprises a pressure adjusting valve arranged on the air pressure adjusting assembly, and the pressure adjusting valve is used for adjusting the air pressure intensity passing through the air pressure adjusting assembly.

Further, first seal chamber includes that a cover is established the first bearing in the guide shaft outside, a cover is established the first sealing washer support in the guide shaft outside, a setting is in just be located on the first sealing washer support with first lip seal between the first bearing, a cover is established the second sealing washer support in the mill axle outside, and a setting is in second lip seal on the second sealing washer support.

Further, the second sealing component comprises a third sealing ring support, a thrust ball bearing, a second bearing and a third lip-shaped sealing ring, wherein the third sealing ring support is arranged on the outer side of the driven shaft in a sleeved mode, the thrust ball bearing is arranged on the outer side of the driven shaft in a sleeved mode, the second bearing is arranged on the outer side of the driven shaft in a sleeved mode, and the third lip-shaped sealing ring is arranged on the third sealing ring support.

Further, the arrangement direction of the flat key is parallel to the axial direction of the guide shaft.

Compared with the prior art, the electric diaphragm pump with the self-protection function provided by the invention has the advantages that the torque adjusting mechanism is arranged between the motor and the diaphragm pump, and specifically, the torque adjusting mechanism comprises a shell arranged on the motor, an end cover arranged on one end of the shell, an air pressure linkage mechanism arranged on the motor and positioned in the shell, an air pressure adjusting assembly arranged on the shell, and a pressure adjusting valve arranged on the air pressure adjusting assembly. The pneumatic linkage mechanism comprises a driving assembly arranged on the motor, a driven shaft arranged at an interval with the driving assembly, a first sealing cavity arranged on the driving assembly, and a second sealing cavity arranged on the driven shaft. The driving assembly comprises a guide shaft, two flat keys and a grinding disc shaft. The grinding disc shaft is arranged on the two flat keys in a sliding mode and penetrates through the first sealing cavity. When the torque loaded by the driven shaft exceeds the rated torque, high-pressure gas is input into the second sealing cavity through the air pressure adjusting assembly, so that the grinding disc shaft is pushed to move towards the direction of the guide shaft, the grinding disc shaft is separated from the driven shaft, the motor idles, and the purpose of protecting the motor and the diaphragm pump when the torque is too large is achieved. The output torque of the grinding disc shaft is related to the air pressure charged by the first air pipe, the output torque of the grinding disc shaft is larger when the charged air pressure is larger, and the output torque of the grinding disc shaft is opposite to the output torque of the grinding disc shaft. The pressure of air charged into the first air pipe is adjusted through a pressure adjusting valve arranged on the first air pipe, so that the torque is adjustable.

Drawings

Fig. 1 is a schematic structural diagram of an electric diaphragm pump with a self-protection function according to the present invention.

Fig. 2 is a schematic cross-sectional view illustrating a torque adjusting mechanism of the electric diaphragm pump having the self-protection function of fig. 1.

Detailed Description

Specific examples of the present invention will be described in further detail below. It should be understood that the description herein of embodiments of the invention is not intended to limit the scope of the invention.

Fig. 1 to 2 are schematic structural views of an electric diaphragm pump with a self-protection function according to the present invention. The electric diaphragm pump having the self-protection function includes an electric motor 10, a torque adjusting mechanism 20 provided on the electric motor 10, and a diaphragm pump 30 provided on the torque adjusting mechanism 20. It is contemplated that the electric diaphragm pump with self-protection function may further include other functional modules, such as assembly components, mounting components, control modules, electrical connection components, etc., which are well known to those skilled in the art and will not be described herein.

The output end of the motor 10 is connected with the torque adjusting mechanism 20, and the motor 10 is used for driving the torque adjusting mechanism 20. Which is per se prior art and will not be described in further detail herein.

The torque adjusting mechanism 20 includes a housing 21 disposed on the motor 10, an end cap 22 disposed on one end of the housing 21, a pneumatic linkage 23 disposed on the motor 10 and located in the housing 21, a pneumatic adjusting assembly 24 disposed on the housing 21, and a pressure regulating valve 25 disposed on the pneumatic adjusting assembly 24.

The housing 21 is a hollow cylindrical structure, and is used to connect the motor 10 and the diaphragm pump 30, and the interior of the housing is used to accommodate the pneumatic linkage mechanism 23. One end of the shell 21 is arranged in the output direction of the motor 10, the output end of the motor extends into the shell 21, and the other end of the shell 21 is provided with the end cover 22.

The end cap 22 is disposed at one end of the housing 21 and connected to the diaphragm pump 30, thereby connecting the torque adjusting mechanism 20 to the diaphragm pump 30.

The pneumatic linkage 23 includes a driving unit 231 disposed on the motor 10, a driven shaft 232 disposed apart from the driving unit 231, a first sealed chamber 233 disposed on the driving unit 231, and a second sealed chamber 234 disposed on the driven shaft 232.

The driving assembly 231 includes a guide shaft 2311 provided on an output side of the motor 10, two flat keys 2312 provided on both sides of the guide shaft 2311, respectively, and a grinding disc shaft 2313 slidably provided on both the flat keys 2312.

One end of the guide shaft 2311 is disposed at the output end of the motor 10, so that the guide shaft 2311 is driven to rotate by the output end of the motor 10. The two flat keys 2312 are respectively disposed at both sides of the other end of the guide shaft 2311. The flat key 2312 is a guide flat key and is located between the guide shaft 2311 and the grinding disc shaft 2313. One side of each flat key 2312 abuts against the outer side of the guide shaft 2311, and the other side of the opposite side abuts against the inner side of the burr shaft 2313. The arrangement direction of the two flat keys 2312 is parallel to the axial direction of the guide shaft 2311. The flat key 2312 is used for movably coupling the disc shaft 2313 and transmitting torque to the disc shaft 2313 through the flat key 2312, so that the disc shaft 2313 rotates with the guide shaft 2311. The grinding disc shaft 2313 is slidably arranged on the two flat keys 2312 and penetrates through the first sealing cavity 233, one end of the grinding disc shaft 2313 is slidably arranged on the two flat keys 2312 and is located in the first sealing cavity 233, and the end face of the other end of the grinding disc shaft 2313 is a flat end and is located in the second sealing cavity 234. Under the action of the pneumatic adjusting assembly 24, the grinding disc shaft 2313 is repeatedly translated along the axial direction of the guide shaft 2311 by the two flat keys 2312, and the principle of the pneumatic adjusting assembly 24 will be described below.

One end of the driven shaft 232 penetrates through the end cover 22 and is connected with the diaphragm pump 30, the end face of the other end is a plane end and is arranged at an interval with the plane end of the grinding disc shaft 2313, and the driven shaft 232 is located in the shell 21. When the grinding disc shaft 2313 axially moves towards the driven shaft 232 and abuts against the driven shaft 232, the plane ends of the grinding disc shaft 2313 and the guide shaft 2311 are tightly attached to each other, so that when the grinding disc shaft 2313 rotates, static friction force is generated between the grinding disc shaft 2313 and the driven shaft 232, and the driven shaft 232 is driven to rotate.

The first seal chamber 233 includes a first bearing 2331 fitted around the outside of the guide shaft 2311, a first seal ring holder 2332 fitted around the outside of the guide shaft 2311, a first lip seal 2333 provided on the first seal ring holder 242, a second seal ring holder 2334 fitted around the outside of the grinding disc shaft 2313, and a second lip seal 2335 provided on the second seal ring holder 2334.

The first bearing 2331 is sleeved outside the guide shaft 2311 and located between the guide shaft 2311 and the housing 21, and the first bearing 2331 is used for supporting the rotation of the guide shaft 2311 and reducing friction, so that the rotation of the guide shaft 2311 is facilitated. The first sealing ring support 2332 is sleeved on the outer side of the guide shaft 2311, and the first sealing ring support 2332 is used for accommodating and fixing the first lip-shaped sealing ring 2333. The first lip seal 2333 is disposed within the first seal support 2332 and between the first seal support 2332 and the first bearing 2331. The second gasket holder 2334 is sleeved outside the grinding disc shaft 2313 and is located between the grinding disc shaft 2313 and the housing 21. The second seal ring holder 2334 is configured to receive and secure the second lip seal ring 2335. The second lip seal 2335 is disposed within the second seal support 2334 and between the second seal support 2334 and the grinding disc shaft 2313. A sealed cavity, i.e. the first sealed cavity 233, is formed between the first and second lip seals 2334, 2335 by the sealing action of the first and second lip seals 2334, 2335.

Second seal chamber 234 includes that a cover establishes third sealing washer support 2341 in the driven shaft 232 outside, a cover establish thrust ball bearing 2342 in the driven shaft 232 outside, a cover establish the second bearing 2343 in the driven shaft 232 outside, and one set up third lip seal circle 2344 on the third sealing washer support 2341.

Third sealing washer support 2341 cover is established the driven shaft 232 outside, and is located the driven shaft 232 with between the shell 21, third sealing washer support 2341 is used for setting up thrust ball bearing 2342, second bearing 2343 and third lip seal circle 2344. Thrust ball bearing 2342 cover is established the driven shaft 232 outside, and is located the driven shaft 232 with between third sealing washer support 2341. The thrust ball bearing 2342 is used for bearing the axial load after the flat ends of the grinding disc shaft 2313 and the guide shaft 2311 are attached to each other, so that the driven shaft 232 is more stable. Second bearing 2343 cover is established the driven shaft 232 outside, and is located driven shaft 232 with between third sealing washer support 2341. The second bearing 2343 is used to support the driven shaft 232 to rotate and reduce friction, thereby facilitating the rotation of the driven shaft 232. The third lip seal 2344 is provided on the third seal ring support 2341, and is located between the third seal ring support 2341 and the driven shaft 232. A sealed cavity, i.e., the second sealed cavity 234, is formed between the second and

third lip seals

2335, 2344 by the sealing action of the second and

third lip seals

2335, 2344.

The air pressure adjusting assembly 24 includes a first air pipe 241 disposed on the first sealed chamber 233 and communicated with the first sealed chamber 233, a second air pipe 242 disposed on the second sealed chamber 234 and communicated with the second sealed chamber 234, an electromagnetic valve 243 disposed on the first and

second air pipes

241, 242, and a temperature sensor 243 disposed outside the housing 21.

One end of the first air pipe 241 is communicated with the first sealed cavity 233, and the other end is connected with the electromagnetic valve 243, so that the electromagnetic valve 243 is communicated with the first sealed cavity 233, and air can enter the first sealed cavity 233 through the first air pipe 241. The second air pipe 242 has one end connected to the second sealing chamber 234 and the other end connected to the solenoid valve 243, so as to connect the solenoid valve 243 to the second sealing chamber 234, and allow air to enter the second sealing chamber 234 through the second air pipe 242. The solenoid valve 243 is connected to the first and second air pipes 43 and 44 and a cylinder (not shown), respectively. The solenoid valve 243 is used to control the gas flow direction, but is prior art and will not be described herein. The temperature sensor 243 is disposed on the outer side wall of the housing 21 and connected to a control module (not shown), and the temperature sensor 243 is located between the grinding disc shaft 2313 and the driven shaft 232, so that the temperature sensor 243 can detect the temperature of the grinding disc shaft 2313 and the driven shaft 232 during the bonding operation and transmit the temperature to the control module.

When the grinding disc type air compressor works, the motor 10 is started and drives the guide shaft 2311 and the grinding disc shaft 2313 to rotate, the air cylinder leads high-pressure air into the electromagnetic valve 243, and the high-pressure air is controlled to enter the first sealing cavity 233 from the first air pipe 241 through the electromagnetic valve 243. Because the grinding disc shaft 2313 is slidably arranged on the guide shaft 2311 through the two flat keys 2312, the high-pressure gas can push the grinding disc shaft 2313 to move towards the driven shaft 232, so that the plane end of the grinding disc shaft 2313 and the plane end of the driven shaft 232 are tightly attached to each other, static friction force is generated between the grinding disc shaft 2313 and the driven shaft 232, and the driven shaft 232 is driven to rotate, so that the purpose of driving the diaphragm pump 30 is achieved. When the torque loaded on the driven shaft 232 exceeds the rated torque, dry friction is generated between the grinding disc shaft 2313 and the driven shaft 232, so that the contact surface between the grinding disc shaft 2313 and the driven shaft 232 can generate heat quickly by friction, and heat can be transferred to the shell 21. And the temperature sensor 243 detects high temperature, and transmits a signal to the control module, and the control module controls the electromagnetic valve 243 to change the output direction of high-pressure gas, so that the high-pressure gas enters the second sealing cavity 234 through the second gas pipe 242, and at this time, the high-pressure gas pushes the grinding disc shaft 2313 to move towards the direction of the guide shaft 2311, so that the grinding disc shaft 2313 is separated from the driven shaft 232, and the motor 10 idles, thereby achieving the purpose of protecting the motor and the diaphragm pump when the torque is too large. When the temperature sensor 243 detects that the temperature is reduced to a specified range, a signal is transmitted to the control module, and the control module controls the electromagnetic valve 243 to change the output direction of the high-pressure gas and circulate in sequence, so that the electric diaphragm pump has a self-protection function.

The pressure regulating valve 25 is disposed on the first air pipe 241, and the pressure regulating valve 25 is used for regulating the pressure of air passing through the first air pipe 241. The output torque (M) of the disc shaft 2313 is equal to the torque (L) multiplied by the force (F) of the disc shaft 2313, and the torque (L) is the rotation torque of the motor 10, which is a constant value, so that the output torque (M) of the disc shaft 2313 is only related to the magnitude of the force (F) of the disc shaft 2313. The force (F) of the grinding disc shaft 2313 is equal to the cross-sectional area (S) of the grinding disc shaft 2313 multiplied by the air pressure (P) charged into the first air pipe 241, and the cross-sectional area (S) of the grinding disc shaft 2313 is also constant, so that the force (F) of the grinding disc shaft 2313 is only related to the air pressure (P) charged into the first air pipe 241. From this, it is possible to obtain the relationship between the pressure level charged in the first air pipe 241 and the output torque of the grinding disc shaft 2313, and the output torque of the grinding disc shaft 2313 is larger when the pressure level charged is larger, and vice versa. Therefore, the pressure of the first air pipe 241 is adjusted by the pressure adjusting valve 25, so as to adjust the torque.

The diaphragm pump 30 is disposed on the torque adjusting mechanism 30, and the driven shaft 232 extends into the diaphragm pump 30, so that the driven shaft 232 rotates to drive the diaphragms at the left and right ends in the diaphragm pump 30 to reciprocate, thereby changing the volume in the cavity of the diaphragm pump 30, and continuously sucking and discharging liquid. The structure and the working principle are the prior art, and are not described in detail herein.

Compared with the prior art, the electric diaphragm pump with the self-protection function provided by the invention has the advantages that the torque adjusting mechanism 20 is arranged between the motor 10 and the diaphragm pump 30, and specifically, the torque adjusting mechanism 20 comprises a shell 21 arranged on the motor 10, an end cover 22 arranged on one end of the shell 21, an air pressure linkage mechanism 23 arranged on the motor 10 and positioned in the shell 21, an air pressure adjusting assembly 24 arranged on the shell 21, and a pressure adjusting valve 25 arranged on the air pressure adjusting assembly 24. The pneumatic linkage 23 includes a driving unit 231 disposed on the motor 10, a driven shaft 232 disposed apart from the driving unit 231, a first sealed chamber 233 disposed on the driving unit 231, and a second sealed chamber 234 disposed on the driven shaft 232. The drive assembly 231 includes a guide shaft 2311, two flat keys 2312, and a burr shaft 2313. Said grinding disc shaft 2313 is slidingly arranged on both said flat keys 2312 and passes through said first sealed chamber 233. When the torque loaded on the driven shaft 232 exceeds the rated torque, high-pressure gas is input into the second sealed cavity 234 through the gas pressure adjusting assembly 24, so that the grinding disc shaft 2313 is pushed to move towards the direction of the guide shaft 2311, the grinding disc shaft 2313 is separated from the driven shaft 232, the motor 10 is idle, and the purpose of protecting the motor 10 and the diaphragm pump 30 when the torque is too large is achieved. The output torque of the grinding disc shaft 2313 is related to the air pressure charged by the first air pipe 241, when the charged air pressure is larger, the output torque of the grinding disc shaft 2313 is larger, and vice versa. The pressure of the air charged into the first air pipe 241 is adjusted by the pressure adjusting valve 25 provided on the first air pipe 241, thereby achieving torque adjustment.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, and any modifications, equivalents or improvements that are within the spirit of the present invention are intended to be covered by the following claims.

Claims

1. The utility model provides an electronic diaphragm pump with self preservation protects function which characterized in that: the electric diaphragm pump with the self-protection function comprises a torque adjusting mechanism, wherein the torque adjusting mechanism comprises a shell, an air pressure linkage mechanism arranged in the shell and an air pressure adjusting assembly arranged on the shell, the air pressure linkage mechanism comprises a driving assembly arranged on the motor, a driven shaft arranged at an interval with the driving assembly, a first sealing cavity arranged on the driving assembly and a second sealing cavity arranged on the driven shaft, the driving assembly comprises a guide shaft arranged in the shell, two flat keys respectively arranged at two sides of the guide shaft and a grinding disc shaft arranged on the two flat keys in a sliding manner, the guide shaft drives the grinding disc shaft to rotate, the two flat keys are respectively arranged at two sides of one end of the guide shaft and are positioned between the guide shaft and the grinding disc shaft, one side face of each flat key is tightly attached to the outer side face of the guide shaft, the other side face of the opposite side face of each flat key is tightly attached to the inner side face of the grinding disc shaft, one end of the grinding disc shaft is arranged on the two flat keys in a sliding mode and located in the first sealing cavity, the end face of the other end of the grinding disc shaft is a plane end and penetrates through the first sealing cavity to extend into the second sealing cavity, the end face of one end of the driven shaft is a plane end and arranged at intervals with the plane end of the grinding disc shaft, the other end of the driven shaft extends out of the shell, and gas enters the first sealing cavity or the second sealing cavity through the air pressure adjusting mechanism and drives the grinding disc shaft to make reciprocating translation so that the grinding disc shaft is in contact with or disconnected with the driven shaft.

2. The electric diaphragm pump with self-protecting function of claim 1, wherein: the electric diaphragm pump with the self-protection function further comprises a motor for driving the torque adjusting mechanism, and a diaphragm pump arranged on the torque adjusting mechanism.

3. The electric diaphragm pump with self-protecting function of claim 1, wherein: the torque adjusting mechanism further comprises an end cover arranged at one end of the shell, and the driven shaft penetrates through the end cover.

4. The electric diaphragm pump with self-protecting function of claim 1, wherein: the air pressure adjusting mechanism comprises a first air pipe, a second air pipe, an electromagnetic valve and a temperature sensor, wherein the first air pipe is arranged on the first sealed cavity and connected with the first sealed cavity, the second air pipe is arranged on the second sealed cavity and communicated with the second sealed cavity, the electromagnetic valve is arranged on the first air pipe and the second air pipe, and the temperature sensor is arranged outside the shell.

5. The electric diaphragm pump with self-protecting function of claim 4, wherein: the temperature sensor is used for detecting the temperature of the joint of the driven shaft and the grinding disc shaft.

6. The electric diaphragm pump with self-protecting function of claim 1, wherein: the torque adjusting mechanism also comprises a pressure adjusting valve arranged on the air pressure adjusting assembly, and the pressure adjusting valve is used for adjusting the air pressure intensity passing through the air pressure adjusting assembly.

7. The electric diaphragm pump with self-protecting function of claim 1, wherein: first seal chamber includes that a cover is established the first bearing in the guide shaft outside, a cover is established the first sealing washer support in the guide shaft outside, a setting is in just be located on the first sealing washer support with first lip seal between the first bearing, a cover is established the second sealing washer support in the mill axle outside, and a setting is in second lip seal on the second sealing washer support.

8. The electric diaphragm pump with self-protecting function of claim 1, wherein: the second sealing assembly comprises a third sealing ring support, a thrust ball bearing, a second bearing and a third lip-shaped sealing ring, wherein the third sealing ring support is arranged on the outer side of the driven shaft in a sleeved mode, the thrust ball bearing is arranged on the outer side of the driven shaft in a sleeved mode, the second bearing is arranged on the outer side of the driven shaft in a sleeved mode, and the third lip-shaped sealing ring is arranged on the third sealing ring.

9. The electric diaphragm pump with self-protecting function of claim 1, wherein: the arrangement direction of the flat key is parallel to the axial direction of the guide shaft.