CN210715029U

CN210715029U - Diaphragm pump with high sealing performance

Info

Publication number: CN210715029U
Application number: CN201921592679.2U
Authority: CN
Inventors: 李才荣
Original assignee: Guangdong Boquan Environmental Protection Technology Co Ltd
Current assignee: Guangdong Boquan Environmental Protection Technology Co Ltd
Priority date: 2019-09-24
Filing date: 2019-09-24
Publication date: 2020-06-09
Anticipated expiration: 2029-09-24

Abstract

The utility model discloses a diaphragm pump with strong sealing performance, which comprises a pump shell, a pump body, a motor, an eccentric wheel, a bearing bracket, a pump shell bracket, a diaphragm, three pistons, an intermediate plate, an O-shaped sealing ring and a triangular sealing ring; the diaphragm adopts a structure that a sealing flange is plugged into a diaphragm sealing groove on the bearing frame, the structure is compact, soft rubber is not easy to deform, and the sealing effect is good; the piston is provided with two rings of annular sealing rib structures, so that the strength of the piston is increased, the injection molding deformation of the piston is reduced, and the sealing effect is enhanced; the contact surface of the piston and the diaphragm adopts an arc structure, so that the contact area of the piston and the diaphragm is reduced, and the tensile strength of the diaphragm and the collision noise between the piston and the diaphragm during the working of the diaphragm pump are favorably reduced; the thickness of the central part of the pump shell bracket is thickened, the strength of the pump shell bracket is enhanced, and the sealing effect between the diaphragm and the middle plate is enhanced; the utility model discloses a plurality of structure cooperation is sealed, promotes the sealed reliability of diaphragm pump, avoids the infiltration, reduces the noise of pump, increases the life of diaphragm pump.

Description

Diaphragm pump with high sealing performance

Technical Field

The utility model relates to a diaphragm pump field indicates a diaphragm pump that leakproofness is strong especially.

Background

The diaphragm pump depends on the eccentric angle of the eccentric wheel, and converts the rotating motion of the motor into the reciprocating motion of the piston through the tight connection between the motor shaft, the eccentric wheel, the bearing frame and the piston, thereby changing the volume of the working cavity to suck and discharge water, in the prior art, the sealing between the water inlet cavity and the outside of the pump shell usually adopts the structure that the edge of the diaphragm sheet is inwards bent into a sealing folded edge and is sealed through the rigid extrusion between the sealing folded edge and the pump shell, because the material of the diaphragm sheet is usually harder rubber (Shore hardness is 87 degrees), and the working cavity of the middle plate is in a higher temperature state (different from 40 ℃ to 80 ℃) when the pump works, the diaphragm sheet of the structure is in a higher temperature cavity for a long time, is easy to age and deform in the reciprocating motion process driven by the piston, the sealing effect of the sealing folded edge is changed along with the lengthening of the service time, and gaps are easy to generate, resulting in water leakage or seepage, directly declaring the premature end of life of the pump.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides a diaphragm pump that multiple sealing method, sealing reliability are strong.

In order to achieve the above object, the utility model adopts the following technical scheme: a diaphragm pump with strong sealing performance comprises a pump shell, a pump body, a rear end cover arranged at the rear end of the pump body, a front end cover arranged at the front end of the pump body, a motor arranged in the pump body, an eccentric wheel, a bearing frame, a pump shell support, a diaphragm, three pistons, an intermediate plate, an O-shaped sealing ring and a triangular sealing ring; the inner part of the front end cover is provided with a cavity, the eccentric wheel is tightly matched with the bearing inner ring, the bearing outer ring is tightly matched with the bearing frame to form a bearing frame assembly which is arranged in the cavity of the front end cover, the eccentric wheel is tightly connected with the output end of the motor, the top of the bearing frame is provided with three cylindrical supporting seats, the top ends of the cylindrical supporting seats are provided with a screw hole, and the periphery of the screw hole is provided with a circle of annular diaphragm; the top of the cylindrical supporting seat protrudes out of the top end of the front end cover; the pump shell support is arranged at the top end of the front end cover, three through holes are formed in the pump shell support, the diameter of each through hole is larger than that of the cylindrical support seat, and the top end of the cylindrical support seat penetrates out of the through hole; the diaphragm is arranged on the top surface of the pump shell support, the diaphragm is provided with three through holes, a circle of diaphragm sealing flange is arranged on the bottom surface of the diaphragm and the periphery of the through hole, the diaphragm sealing flange is matched with a diaphragm sealing groove on the cylindrical support seat, and a circle of middle plate positioning flange is annularly arranged on the periphery of the top surface of the diaphragm; the piston is arranged on the top surface of the diaphragm, a stepped hole is arranged in the middle of the piston, and the piston and the diaphragm are fixed on the cylindrical supporting seat through bolts penetrating through the stepped hole in the middle of the piston, the through hole in the diaphragm and the screw hole of the cylindrical supporting seat; the middle plate is arranged on the top surfaces of the diaphragm and the pistons, three working cavities are arranged on the inner side of the middle plate, and the three pistons are respectively arranged in the three working cavities of the middle plate; the periphery of the bottom surface of the middle plate is provided with a circle of grooves, and the grooves are matched with the middle plate positioning flanges on the top surface of the diaphragm; a circle of triangular annular steps are arranged on the periphery of the top surface of the middle plate, and a triangular sealing ring is sleeved above the triangular annular steps; the top of the middle plate is provided with a circle of annular groove, and an O-shaped sealing ring is arranged in the annular groove; the pump shell is arranged on the outer side of the middle plate, the pump shell support, the diaphragm and the front end cover are assembled into a whole through bolts, the middle plate and the pump shell are sealed together to form a water outlet cavity in the center of the pump shell, a pump shell water inlet cavity is arranged on the periphery of the water outlet cavity, a water inlet pipe orifice and a water outlet pipe orifice are arranged on the upper portion of the pump shell, the water inlet pipe orifice is communicated with the pump shell water inlet cavity, the water outlet pipe orifice is communicated with the pump shell water outlet cavity, three working cavities of the middle plate are respectively provided with a suction valve, the suction valves are one-way valves which can only conduct from the pump shell water inlet cavity to the middle plate working cavity in one way, the water outlet pipe orifice is communicated with the pump shell water outlet cavity.

Furthermore, the diaphragm is 2mm in thickness and is integrally formed by injection molding of soft rubber TPV 201-87.

Furthermore, a piston positioning column is arranged on the top surface of the diaphragm, and a piston positioning hole is arranged on the contact surface of the piston and the diaphragm.

Furthermore, two rings of annular sealing ribs are arranged on the periphery of the stepped hole of the piston and the contact surface of the piston and the diaphragm, and the contact surface of the piston and the diaphragm is arc-shaped.

Further, the thickness of the periphery of the pump casing support is 6mm, and the thickness of the central part of the pump casing support is 0.3-0.4mm thicker than that of the periphery.

Furthermore, the triangular sealing ring is made of soft rubber, ageing deformation caused by temperature and service life lengthening is not prone to occurring, the cross section of the triangular sealing ring is square, the triangular annular step is combined with the triangular sealing ring with the square cross section, sealing reliability of the diaphragm pump is improved, and water seepage from a water inlet cavity of the pump shell to the outside is effectively avoided.

Furthermore, the O-shaped sealing ring is made of soft rubber, the cross section of the O-shaped sealing ring is circular, and the annular groove is combined with the O-shaped sealing ring with the circular cross section, so that the reliability of isolation between the water inlet cavity and the water outlet cavity is improved.

Furthermore, three positioning bulges are arranged on the bottom surface of the diaphragm, positioning concave holes matched with the positioning bulges are arranged on the top surface of the pump shell support, and during installation, the positioning bulges are plugged into the positioning concave holes to be installed in place.

Furthermore, three pistons, three through holes on a pump shell support, three cylindrical supporting seats on the top of the bearing frame, three through holes on the diaphragm and three working cavities of the middle plate are uniformly distributed at included angles of 120 degrees.

Furthermore, the upper part of the pump shell is also provided with a pressure relief mechanism, and the pressure relief mechanism is characterized in that a water outlet cavity of the pump shell is communicated with a water inlet cavity when the pressure is too high so as to reduce the pressure of the water outlet cavity and protect the diaphragm pump; the pressure relief mechanism comprises a pressure regulating valve plate, a spring seat, a pressure relief spring, a pressure relief cover and a pressure relief cover, wherein the pressure regulating valve plate, the spring seat, the pressure relief spring, the pressure relief cover and the pressure relief cover are sequentially arranged from bottom to top, and the pressure relief cover is fixed on the pump shell through bolts.

Furthermore, a bottom plate is arranged on the bottom surface of the pump body, and a plurality of shock pads are arranged on the bottom plate.

The beneficial effects of the utility model reside in that: the diaphragm of the utility model adopts the structure that the sealing flange is plugged into the diaphragm sealing groove of the cylindrical supporting seat of the bearing frame, the structure is compact, and the sealing effect is good; the water seepage from the working cavity of the middle plate to the diaphragm can be effectively avoided; the top surface of the middle plate is provided with a sealing structure of a triangular annular step combined with a triangular sealing ring with a square cross section, the triangular sealing ring is made of soft rubber, ageing deformation caused by temperature and service time extension is not easy to generate, the sealing reliability of the diaphragm pump is improved, water seepage from a water inlet cavity of a pump shell to the outside can be effectively avoided, the assembly requirement is simplified, and the working efficiency is improved; the piston is provided with two rings of annular sealing rib structures, so that the sealing effect of the piston is improved, the strength of the piston is increased, the injection molding deformation of the piston is reduced, the contact surface of the piston and the diaphragm adopts an arc structure, the contact area of the piston and the diaphragm is reduced, and the tensile strength of the diaphragm and the collision noise between the piston and the diaphragm during the operation of the diaphragm pump are reduced; the thickness of the central part of the pump shell support is thickened, the strength of the pump shell support is enhanced, and meanwhile, the sealing effect between the diaphragm and the middle plate can be enhanced; the utility model discloses a plurality of structure cooperation, multiple sealing mode promote the sealed reliability of diaphragm pump, avoid the infiltration, increase the life of diaphragm pump.

Drawings

Fig. 1 is an explosion diagram of the whole structure of the utility model.

Fig. 2 is a schematic structural view of the top surface of the diaphragm of the present invention.

Fig. 3 is a schematic view of the bottom structure of the diaphragm of the present invention.

Fig. 4 is a schematic structural view of the top surface of the pump casing bracket of the present invention.

Fig. 5 is a schematic view of the bottom structure of the piston of the present invention.

Fig. 6 is a schematic structural view of the top surface of the middle plate of the present invention.

Fig. 7 is a schematic view of the bottom structure of the middle plate of the present invention.

Detailed Description

Referring to fig. 1-7, the present invention relates to a diaphragm pump with high sealing performance, which comprises a pump housing 1, a pump body 2, a rear end cap 21 disposed at the rear end of the pump body, a front end cap 22 disposed at the front end of the pump body, a motor (not shown) disposed inside the pump body, an eccentric wheel 28, a bearing 23, a bearing frame 24, a pump housing support 3, a diaphragm 4, three pistons 5, a middle plate 6, an O-shaped sealing ring 68, and a triangular sealing ring 65; a cavity is arranged in the front end cover 22, the eccentric wheel 28 is tightly matched with the inner ring of the bearing 23, the outer ring of the bearing 23 is tightly matched with the bearing frame 24 to form a bearing frame assembly which is arranged in the cavity of the front end cover 22, the eccentric wheel 28 is connected with the output end of the motor, three cylindrical supporting seats 25 are arranged at the top of the bearing frame 24, a screw hole 251 is arranged at the top end of each cylindrical supporting seat 25, and a circle of diaphragm sealing grooves 252 are arranged at the periphery of each screw; the top of the cylindrical support seat 25 protrudes out of the top end of the front end cover 22; the pump shell support 3 is arranged at the top end of the front end cover 22, three through holes 31 are formed in the pump shell support 3, the diameter of each through hole 31 is larger than that of the cylindrical support seat 25, and the top end of the cylindrical support seat 25 penetrates out of the through hole 31; the diaphragm 4 is arranged on the top surface of the pump shell bracket 3, the diaphragm 4 is provided with three through holes 41, a circle of diaphragm sealing flange 42 is arranged on the bottom surface of the diaphragm 4 and the periphery of the through holes, the diaphragm sealing flange 42 is matched with a diaphragm annular positioning groove 252 on the cylindrical supporting seat 25, and a circle of middle plate positioning flange 43 is annularly arranged on the periphery of the top surface of the diaphragm 4; the piston 5 is arranged on the top surface of the diaphragm 4, a stepped hole 51 is arranged in the middle of the piston 5, and the piston 5 and the diaphragm 4 are fixed on the cylindrical support seat 25 through the stepped hole 51 in the middle of the piston 5, the through hole 41 in the diaphragm 4 and the screw hole 251 of the cylindrical support seat by the bolt 7; the middle plate 6 is arranged on the top surfaces of the diaphragm 4 and the pistons 5, three working cavities are arranged on the inner side of the middle plate 6, and the three pistons 5 are respectively arranged in the three working cavities of the middle plate 6; a circle of grooves 61 are formed in the periphery of the bottom surface of the middle plate 6, and the grooves 61 are matched with the middle plate positioning flanges 43 on the top surface of the diaphragm 4; a circle of triangular annular steps 64 are arranged on the periphery of the top surface of the middle plate 6, and a triangular sealing ring 65 is sleeved above the triangular annular steps 64; the top of the middle plate 6 is provided with a ring of annular groove 69, and an O-shaped sealing ring 68 is arranged in the annular groove 69; the pump shell 1 is arranged on the outer side of the middle plate 6, the pump shell 1, the pump shell bracket 3, the diaphragm 4 and the front end cover 22 are assembled into a whole through bolts 7, the number of the bolts 7 is 6, and 6 mounting holes are uniformly distributed in the pump shell 1, the pump shell bracket 3 and the front end cover 22; the middle plate 6 is sealed with the pump case 1 to form a water outlet cavity at the center of the pump case 1, the periphery of the water outlet cavity is a water inlet cavity of the pump case 1, the upper part of the pump case 1 is provided with a water inlet pipe orifice 11 and a water outlet pipe orifice 12, the water inlet pipe orifice 11 is communicated with the water inlet cavity, the water outlet pipe orifice 12 is communicated with the water outlet cavity, three working cavities of the middle plate 6 are respectively provided with a suction valve 62, the suction valve 62 is a one-way valve which can only be conducted from the water inlet cavity of the pump case 1 to the working cavity of the middle plate 6 in a one-way, the water outlet pipe orifice is communicated with the water outlet cavity of the pump case 1, the central part of the top of the middle plate 6 (namely the back of the working cavity) is provided with a discharge valve 63, the discharge valve 63 is a one-way valve which can be conducted from the working cavity of the middle plate 6 to the water outlet cavity of the pump case, the suction valve 62 is opened, and the water in the water inlet pipe orifice 11 is sucked into the working cavity of the intermediate plate 6 through the water inlet cavity of the pump shell 1; the working cavity of the middle plate 6 is also provided with a plurality of drain holes 67, the drain holes 67 are shielded by the drain valve 63 from the outside, the drain valve 63 is also made of soft rubber, when the piston 5 and the diaphragm move upwards under the driving of the motor, water in the working cavity is pressed out to the drain holes 67, the drain valve 63 is opened, and the water flows to the water outlet cavity of the pump shell 1 and completes water flow pressurization through the water outlet pipe orifice 12.

In some embodiments, the membrane sheet 4 has a thickness of 2mm and is integrally injection-molded from TPVs 201-87 (an imported soft rubber), and the membrane sheet 4 made of the material will not age, deform and cause water seepage and leakage even after long-term use.

In some embodiments, piston positioning post 44 is disposed on the top surface of diaphragm 4, and piston positioning hole 52 is disposed on the contact surface between piston 5 and diaphragm 4, so that when mounting, piston positioning post 44 is completely inserted into piston positioning hole 52 of piston 5 for mounting.

In some embodiments, two rings of annular sealing ribs 53 are arranged on the periphery of the stepped hole 51 of the piston 5 and the contact surface of the piston 5 and the diaphragm 4, and the contact surface of the piston 5 and the diaphragm 4 is arc-shaped, so that the contact area of the piston 5 and the diaphragm 4 is reduced, and the tensile strength of the diaphragm 4 and the collision noise between the piston 5 and the diaphragm 4 during the operation of the diaphragm pump are reduced.

In some embodiments, the pump casing support 3 has a thickness of 6mm around its circumference, and the pump casing support 3 has a thickness of 0.3 to 0.4mm in the central portion thereof, thereby enhancing the strength of the pump casing support 3 and enhancing the sealing effect between the diaphragm 4 and the intermediate plate 6.

In some embodiments, the triangular sealing ring 65 is made of soft rubber, is not easy to age and deform due to the increase of temperature and service time, has a square cross section, and is combined with the triangular sealing ring with the square cross section, so that the sealing reliability of the diaphragm pump is improved, and water seepage from a water inlet cavity of the pump shell to the outside is effectively avoided;

in some embodiments, the O-ring seal 68 is made of a soft rubber material with a circular cross-section, and the annular groove 69 in combination with the O-ring seal 68 with a circular cross-section improves the reliability of the isolation between the inlet chamber and the outlet chamber.

In some embodiments, three positioning protrusions 45 are disposed on the bottom surface of the diaphragm 4, and positioning concave holes 32 adapted to the positioning protrusions are disposed on the top surface of the pump casing support 3, so that the positioning protrusions 45 are inserted into the positioning concave holes 32 to be mounted in place during mounting.

In some embodiments, three pistons 5, three through holes 31 in the pump housing frame 3, three cylindrical support seats 25 at the top of the bearing frame 24, three through holes 41 in the diaphragm 4, and three working chambers of the intermediate plate 6 are uniformly distributed at an angle of 120 ° with respect to each other.

In some embodiments, the upper portion of the pump case 1 is further provided with a pressure relief mechanism, when the pressure of the water outlet cavity of the pump case 1 is too high, the pressure relief mechanism is communicated with the water inlet cavity, and the pressure relief mechanism comprises a pressure regulating valve plate 13, a spring seat 14, a pressure relief spring 15, a pressure relief cover 16 and a pressure relief cover 16, which are sequentially arranged from bottom to top, and the pressure relief cover 16 is fixed on the pump case through a bolt 7.

In some embodiments, the bottom surface of the pump body 2 is provided with a bottom plate 26, and the bottom plate 26 is provided with a plurality of shock absorbing pads 27.

In some embodiments, the water inlet nozzle 11 and the water outlet nozzle 12 may be a threaded connection interface or a direct-insertion connection interface.

The above embodiments are only for describing the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made by the technical solution of the present invention by those skilled in the art are all within the scope of the present invention as defined by the claims.

Claims

1. The utility model provides a diaphragm pump that leakproofness is strong which characterized in that: the pump comprises a pump shell (1), a pump body (2), a rear end cover (21) arranged at the rear end of the pump body, a front end cover (22) arranged at the front end of the pump body, a motor arranged in the pump body, an eccentric wheel (28), a bearing (23), a bearing frame (24), a pump shell bracket (3), a diaphragm sheet (4), three pistons (5), an intermediate plate (6), an O-shaped sealing ring (68) and a triangular sealing ring (65); a cavity is arranged in the front end cover (22), the eccentric wheel (28) is tightly matched with the inner ring of the bearing (23), the outer ring of the bearing (23) is tightly matched with the bearing frame (24) to form a bearing frame assembly which is arranged in the cavity of the front end cover (22), the eccentric wheel (28) is tightly connected with the output end of the motor, three cylindrical supporting seats (25) are arranged at the top of the bearing frame (24), a screw hole (251) is arranged at the top end of each cylindrical supporting seat (25), and a circle of annular diaphragm sealing groove (252) is arranged on the periphery of the screw hole (251); the top of the cylindrical supporting seat (25) protrudes out of the top end of the front end cover (22); the pump shell support (3) is arranged at the top end of the front end cover (22), three through holes (31) are formed in the pump shell support (3), the diameter of each through hole (31) is larger than that of the cylindrical supporting seat (25), and the top end of the cylindrical supporting seat (25) penetrates out of the through hole (31); the diaphragm (4) is arranged on the top surface of the pump shell support (3), the diaphragm (4) is provided with three through holes (41), a circle of diaphragm sealing flange (42) is arranged on the bottom surface of the diaphragm (4) and on the periphery of the through holes, the diaphragm sealing flange (42) is matched with a diaphragm sealing groove (252) on the cylindrical support seat (25), and a circle of middle plate positioning flange (43) is annularly arranged on the periphery of the top surface of the diaphragm (4); the piston (5) is arranged on the top surface of the diaphragm (4), a stepped hole (51) is formed in the middle of the piston (5), and the piston (5) and the diaphragm (4) are fixed on the cylindrical support seat (25) through a bolt (7) penetrating through the stepped hole (51) in the middle of the piston (5), a through hole (41) in the diaphragm (4) and a screw hole (251) of the cylindrical support seat; the middle plate (6) is arranged on the top surfaces of the diaphragm (4) and the pistons (5), three working cavities are arranged on the inner side of the middle plate (6), and the three pistons (5) are respectively arranged in the three working cavities of the middle plate (6); a circle of grooves (61) are formed in the periphery of the bottom surface of the middle plate (6), and the grooves (61) are matched with the middle plate positioning flanges (43) on the top surface of the diaphragm (4); a circle of triangular annular steps (64) are arranged on the periphery of the top surface of the middle plate (6), and a triangular sealing ring (65) is sleeved above the triangular annular steps (64); a ring of annular groove (69) is formed in the top of the middle plate (6), and an O-shaped sealing ring (68) is arranged in the annular groove (69); the pump shell (1) is arranged on the outer side of the middle plate (6), the pump shell (1), the pump shell bracket (3), the diaphragm (4) and the front end cover (22) are assembled into a whole through a bolt (7), the middle plate (6) and the pump shell (1) are sealed together to form a water outlet cavity in the center of the pump shell (1), the periphery of the water outlet cavity is a water inlet cavity of the pump shell (1), the upper part of the pump shell (1) is provided with a water inlet pipe orifice (11) and a water outlet pipe orifice (12), the water inlet pipe orifice (11) is communicated with the water inlet cavity of the pump shell (1), the water outlet pipe orifice (12) is communicated with the water outlet cavity of the pump shell (1), three working cavities of the middle plate (6) are respectively provided with a suction valve (62), the suction valve (62) is a one-way valve which can only be communicated from the water inlet cavity of the pump shell (1) to the working cavity, the central part of the top of the middle plate (6) is provided with a discharge valve (63), and the discharge valve (63) is a one-way valve for one-way conduction from the working cavity of the middle plate (6) to the water outlet cavity of the pump shell (1).

2. A diaphragm pump having high sealing performance according to claim 1, wherein: the diaphragm (4) is 2mm thick and is integrally formed by injection molding of soft rubber TPV 201-87.

3. A diaphragm pump having high sealing performance according to claim 1, wherein: and a piston positioning column (44) is arranged on the top surface of the diaphragm (4), and a piston positioning hole (52) is arranged on the contact surface of the piston (5) and the diaphragm (4).

4. A diaphragm pump having high sealing performance according to claim 1 or 3, wherein: two rings of annular sealing ribs (53) are arranged on the periphery of the stepped hole (51) of the piston (5) and the contact surface of the piston and the diaphragm (4), and the contact surface of the piston (5) and the diaphragm (4) is arc-shaped.

5. A diaphragm pump having high sealing performance according to claim 1, wherein: the thickness of the periphery of the pump shell support (3) is 6mm, and the thickness of the central part of the pump shell support (3) is 0.3-0.4mm larger than that of the periphery.

6. A diaphragm pump having high sealing performance according to claim 1, wherein: the triangular sealing ring (65) is made of soft rubber, and the cross section of the triangular sealing ring is square; the O-shaped sealing ring (68) is made of soft rubber, and the cross section of the O-shaped sealing ring is circular.

7. A diaphragm pump having high sealing performance according to claim 1, wherein: be equipped with three location arch (45) on the bottom surface of diaphragm (4), be equipped with on pump case support (3) top surface with location protruding looks adaptation location shrinkage pool (32), during the installation, location arch (45) are plugged in location shrinkage pool (32) and are target in place for the installation.

8. A diaphragm pump having high sealing performance according to claim 1, wherein: the three pistons (5), the three through holes (31) on the pump shell bracket (3), the three cylindrical supporting seats (25) at the top of the bearing frame (24), the three through holes (41) on the diaphragm (4) and the three working cavities of the middle plate (6) are uniformly distributed with included angles of 120 degrees.

9. A diaphragm pump having high sealing performance according to claim 1, wherein: the upper part of the pump shell (1) is also provided with a pressure relief mechanism, and the pressure relief mechanism is characterized in that a water outlet cavity of the pump shell (1) is communicated with a water inlet cavity when the pressure is too high so as to reduce the pressure of the water outlet cavity and protect the diaphragm pump; the pressure relief mechanism comprises a pressure regulating valve plate (13), a spring seat (14), a pressure relief spring (15) and a pressure relief cover (16) which are sequentially arranged from bottom to top, wherein the pressure relief cover (16) is fixed on a pump shell through a bolt (7).

10. A diaphragm pump having high sealing performance according to claim 1, wherein: the pump body (2) bottom surface is equipped with bottom plate (26), be equipped with a plurality of shock pad (27) on bottom plate (26).