Four-plunger diaphragm pump capable of being completely emptied

Abstract

The four-plunger diaphragm pump comprises a liquid inlet pipe, a liquid discharge pipe, a pump body and a shaft body, the pump body is fixedly connected with the liquid inlet pipe, a first one-way valve is installed in the pump body, a valve plate and a diaphragm pressing plate are fixed between the pump body and the shaft body, the valve plate is provided with a second one-way valve, and the diaphragm pressing plate is provided with a second one-way valve. The diaphragm between the valve plate and the diaphragm pressing plate is fixed by the valve plate and the diaphragm pressing plate; a shaft shoulder is arranged at the position, where the first bearing is installed, of the shaft body, the first bearing is fixed to the inner wall of the shaft body through a first bearing pressing plate, the eccentric shaft is connected with the first bearing and extends out of the pump body, an eccentric disc is installed at the end, located in the pump body, of the eccentric shaft through a second bearing, and the eccentric disc abuts against a diaphragm fixing block. And the diaphragm fixing block is connected with the diaphragm. Through structural cooperation of the shaft body, the pump body, the valve plate and the diaphragm pressing plate, suction force can be generated through periodic deformation of the diaphragm to transport materials, and full emptying of the materials is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of biopharmaceutical delivery pumps, and in particular relates to a four-plunger diaphragm pump that can be fully emptied. Background Art

[0002] Nowadays, the biopharmaceutical industry often uses four-plunger diaphragm pumps to transport materials. They have the advantages of safe, reliable and efficient transportation of biotechnology materials, and have low friction, low shear and low pulsation operating characteristics, etc., which can better serve the biopharmaceutical production work.

[0003] The existing four-plunger diaphragm pump has the problem that the residual liquid in the pump chamber cannot be completely discharged, which affects the actual transportation needs. In addition, the material that has not been discharged for a long time will affect the transportation or may deteriorate and pollute. Summary of the invention

[0004] The purpose of the present invention is to provide a fully emptied four-plunger diaphragm pump to solve the problem in the prior art that the residual liquid in the pump chamber cannot be completely discharged, affecting the actual transportation needs. In addition, the long-term accumulation of undischarged materials will affect transportation or may deteriorate and pollute.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A four-plunger diaphragm pump capable of full emptying, comprising a liquid inlet pipe, a liquid discharge pipe, a pump body and a shaft body, wherein materials enter the pump body and the shaft body from the liquid inlet pipe and are discharged from the liquid discharge pipe, wherein the pump body is fixedly connected to the liquid inlet pipe, wherein a first one-way valve is installed inside the pump body, wherein a valve plate and a diaphragm pressure plate are fixed between the pump body and the shaft body, wherein a second one-way valve is installed on the valve plate, wherein the valve plate and the diaphragm pressure plate are abutted against each other, and wherein the valve plate and the diaphragm pressure plate fix a diaphragm therebetween; It needs to be understood that the pump body is provided with four shaft mounting thread grooves in a rectangular distribution on the plane connecting the shaft body, and the shaft body is provided with four shaft thread holes in a rectangular distribution. The arrangement of the four shaft thread holes is the same as the arrangement of the four shaft mounting thread grooves. Threaded connectors such as bolts or nuts are passed through the shaft thread holes and installed into the shaft mounting thread grooves. The valve plate is placed on the pump body, and then the diaphragm pressure plate is placed on the valve plate. The pump body and the shaft body press the valve plate and the diaphragm pressure plate to fix them. The connecting surfaces of the pump body and the shaft body are processed by other processes (such as sealing).

[0006] A shaft shoulder is provided at the position where the first bearing is installed on the shaft body, and the first bearing is fixed to the inner wall of the shaft body through a first bearing pressure plate, and an eccentric shaft is installed on the shaft body, and the eccentric shaft is connected to the first bearing and extends out of the pump body, and an eccentric disk is installed on one end of the eccentric shaft located inside the pump body through a second bearing, and the eccentric disk is abutted against a diaphragm fixing block, and the diaphragm fixing block is connected to the diaphragm, and the material enters the pump body from the liquid inlet pipe, flows into the first space formed by the pump body, the valve plate and the diaphragm through the first one-way valve, flows into the second space formed by the pump body and the valve plate through the second one-way valve, and flows into the discharge pipe through the axial channel of the pump body.

[0007] It should be understood that the first one-way valve can be a ball one-way valve, an electric one-way valve, a spring one-way valve, a diaphragm one-way valve, a lifting one-way valve, a swing one-way valve, and a stop one-way valve. The eccentric shaft is externally connected to a motor or other rotating drive device to achieve rotational motion. The eccentric shaft rotates, and the first bearing supports the eccentric shaft for stable operation. The eccentric shaft drives the eccentric disk to rotate, and the eccentric disk squeezes the diaphragm fixing block. The movement of the diaphragm fixing block causes the diaphragm to perform periodic compression and recovery motion to generate suction, so that the material enters the pump body from the liquid inlet pipe, enters the first space through the first one-way valve, and then flows into the second space through the second one-way valve and is discharged through the discharge pipe.

[0008] Preferably, the pump body is provided with an inlet channel, a cylindrical groove, a first one-way valve mounting hole, a drainage groove, and a drainage channel. The inlet channel, the cylindrical groove, and the first one-way valve mounting hole are connected in sequence. The inlet channel is arranged along the radial direction of the pump body, the inlet channel is connected to the inlet pipe, the cylindrical groove and the first one-way valve mounting hole are connected, the cylindrical groove and the first one-way valve mounting hole are located at the center of the pump body and are through-processed. The drainage groove is an annular structure, the drainage groove is a part of the second space, the drainage channel is arranged relative to the axial direction of the pump body, and the drainage channel is connected to the drainage pipe.

[0009] It should be understood that a cylindrical groove is first processed on the pump body, and a first one-way valve mounting hole smaller than the diameter of the cylindrical groove is processed on the basis of the cylindrical groove, and the cylindrical groove is sealed by the end cover through welding or other processes; in the direction parallel to the central axis of the pump body, the maximum distances between the drainage groove and the drainage channel relative to the central axis of the pump body are equal; the material enters the cylindrical groove from the inlet channel and passes through the first one-way valve, and the material enters the drainage channel from the drainage groove and is discharged through the drainage pipe; the pump body is provided with two symmetrically distributed drainage pipe mounting threaded grooves on the plane where the drainage pipe is installed, and the drainage pipe is provided with two rectangularly distributed drainage pipe threaded holes, and the arrangement of the two drainage pipe threaded holes is the same as the arrangement of the two drainage pipe mounting threaded grooves, and threaded connectors such as bolts or nuts are passed through the drainage pipe threaded holes and installed into the drainage pipe mounting threaded grooves.

[0010] Preferably, the valve plate is provided with a first liquid reservoir, an infusion hole, a second liquid reservoir and a second one-way valve mounting hole for mounting a second one-way valve; the first liquid reservoir, the infusion hole and the second liquid reservoir are sequentially connected and are part of the first space; the infusion hole and the second liquid reservoir are distributed around the center line of the valve plate; the first liquid reservoir is located at the center of the valve plate; the second one-way valve mounting holes are distributed in an annular manner; the material enters the first liquid reservoir through the first one-way valve.

[0011] It should be understood that the second one-way valve can be one of a ball one-way valve, a diaphragm one-way valve, a lifting one-way valve, and a swing one-way valve; the material enters the first liquid storage tank through the first one-way valve, and reaches the second liquid storage tank through the infusion hole, and then moves to the second one-way valve.

[0012] Preferably, the diaphragm pressing plate is provided with an annular groove and pressing plate through holes, the pressing plate through holes are distributed in an annular shape, and the edge of the diaphragm is inserted into the annular groove.

[0013] It should be understood that the diaphragm is divided into two parts. The first part is the part corresponding to the through hole of the diaphragm pressure plate in the axial direction of the pressure plate, and the second part is the remaining part of the diaphragm except the first part. The diaphragm pressure plate presses the second part of the diaphragm; the diaphragm and a part of the diaphragm fixing block are in the space of the through hole of the pressure plate.

[0014] Preferably, the diaphragm is provided with annularly distributed protrusions, and the diaphragm fixing block is provided with protrusion slots, and the protrusions are inserted into the protrusion slots.

[0015] It should be understood that the diaphragm is divided into two parts, the first part is the part corresponding to the through hole of the diaphragm pressure plate in the axial direction, and the second part is the remaining part of the diaphragm except the first part, and the protrusion of the diaphragm is located in the first part.

[0016] Preferably, the diaphragm fixing blocks are distributed around the center line of the diaphragm.

[0017] It should be understood that the diaphragm fixing blocks correspond to the number of protrusions of the diaphragm and are provided in multiple groups.

[0018] Preferably, the second one-way valve and the second one-way valve mounting holes are provided in multiple groups and are distributed around the center line of the valve plate.

[0019] It should be understood that the number of combinations of the second one-way valve and the second one-way valve mounting hole is the same as the number of combinations of the diaphragm fixing block and the protrusion.

[0020] Preferably, the shaft body is provided with a first mounting groove, a second mounting groove, and a third mounting groove forming a stepped structure, the first bearing is installed in the first mounting groove, the first bearing pressure plate is installed in the second mounting groove, and the eccentric disk and a part of the diaphragm fixing block are located in the third mounting groove.

[0021] Preferably, the eccentric disk has a second bearing mounting groove into which the second bearing can be installed, and the eccentric disk is in surface contact with the diaphragm fixing block.

[0022] Preferably, the pump body is installed with an end cover, and the center line of the end cover coincides with the center line of the pump body.

[0023] It should be understood that the position of the pump body end cover is provided with four end cover mounting threaded grooves in a rectangular distribution, and the end cover is provided with four end cover threaded holes in a rectangular distribution. The arrangement of the four end cover threaded holes is the same as the arrangement of the four end cover mounting threaded grooves. Threaded connectors such as bolts or nuts are passed through the end cover threaded holes and installed into the end cover mounting threaded grooves.

[0024] By providing a pump body and a shaft body, the eccentric shaft is connected to an external rotating power source to rotate, the first bearing supports the eccentric shaft to operate stably, the eccentric shaft drives the eccentric disk to rotate, the eccentric disk squeezes the diaphragm fixing block, the movement of the diaphragm fixing block causes the diaphragm to perform periodic compression and recovery movement to generate suction, the suction material enters the pump body from the liquid inlet pipe, enters the cylindrical groove from the liquid inlet channel, flows into the first space formed by the pump body, the valve plate, and the diaphragm through the first one-way valve, that is, enters the first liquid storage tank through the first one-way valve, and reaches the second liquid storage tank through the infusion hole, flows into the second space formed by the pump body and the valve plate through the second one-way valve (enters the drainage tank through the second one-way valve), enters the drainage pipe through the drainage channel and is discharged.

[0025] By providing a drainage channel and a drainage groove, in a direction parallel to the central axis of the pump body, the maximum distances between the drainage groove and the drainage channel relative to the central axis of the pump body are equal, ensuring that the material completely flows out of the drainage channel, that is, completely flows out of the pump body to achieve full emptying. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a cross-sectional view of a fully evacuable four-plunger diaphragm pump according to an embodiment of the present application cut along a first plane.

[0027] Figure 2 This is a cross-sectional view of the fully evacuable four-plunger diaphragm pump according to an embodiment of the present application cut along a second plane.

[0028] Figure 3 It is a schematic plan view of a four-plunger diaphragm pump that can be fully emptied according to an embodiment of the present application.

[0029] Figure 4 It is a three-dimensional schematic diagram of the pump body in the fully emptied four-plunger diaphragm pump according to an embodiment of the present application.

[0030] Figure 5 It is a three-dimensional schematic diagram of the end cover of the four-plunger diaphragm pump that can be fully emptied according to an embodiment of the present application.

[0031] Figure 6 It is a three-dimensional schematic diagram of the central axis of a four-plunger diaphragm pump that can be fully emptied according to an embodiment of the present application.

[0032] Figure 7 This is a cross-sectional view of the central shaft of a four-plunger diaphragm pump that can be fully emptied according to an embodiment of the present application.

[0033] Figure 8 It is a three-dimensional schematic diagram of the valve plate in the fully evacuable four-plunger diaphragm pump according to an embodiment of the present application.

[0034] Fig. 9 This is a cross-sectional view of a valve plate in a fully evacuable four-plunger diaphragm pump according to an embodiment of the present application.

[0035] Fig.10 It is a schematic plan view of a valve plate in a four-plunger diaphragm pump that can be fully emptied according to an embodiment of the present application.

[0036] Fig.11 It is a three-dimensional schematic diagram of the diaphragm pressure plate in the four-plunger diaphragm pump that can be fully emptied according to an embodiment of the present application.

[0037] Fig.12 This is a perspective view of a diaphragm fixing block in a four-plunger diaphragm pump that can be fully emptied according to an embodiment of the present application.

[0038] As shown in the figure: 1. pump body; 101. liquid inlet channel; 102. cylindrical groove; 103. first one-way valve mounting hole; 104. drainage groove; 105. drainage channel; 2. valve plate; 21; first liquid storage tank; 22. infusion hole; 23. second liquid storage tank; 24. second one-way valve mounting hole; 3. first one-way valve; 4. second one-way valve; 5. diaphragm; 51. protrusion; 6. diaphragm pressure plate; 61. annular groove; 62. pressure plate through hole; 7. diaphragm fixing block; 71. protrusion slot; 8. shaft body; 81. first mounting groove; 82. second mounting groove; 83. third mounting groove; 9. eccentric disk; 91. second bearing mounting groove; 10. first bearing; 11. first bearing pressure plate; 12. second bearing; 13. eccentric shaft; 14. liquid inlet pipe; 15. drainage pipe; 16. end cover. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0040] In one embodiment, reference Figure 1and Figure 2 , a four-plunger diaphragm pump that can be fully emptied, the material enters the pump body 1 from the liquid inlet pipe 14, flows into the first space formed by the pump body 1, the valve plate 2, and the diaphragm 5 through the first one-way valve 3, flows into the second space formed by the pump body 1 and the valve plate 2 through the second one-way valve 4, and flows into the discharge pipe 15 through the axial channel of the pump body 1, including the liquid inlet pipe 14, the discharge pipe 15, the pump body 1 and the shaft body 8, the material enters the interior of the pump body 1 and the shaft body 8 from the liquid inlet pipe 14 and is discharged from the discharge pipe 15, the pump body 1 is fixedly connected to the liquid inlet pipe 14, reference Figure 4 The pump body 1 is provided with a liquid inlet channel 101, a cylindrical groove 102, a first one-way valve mounting hole 103, a liquid discharge groove 104, and a liquid discharge channel 105. The pump body 1 is first processed with a cylindrical groove 102, and a first one-way valve mounting hole 103 having a smaller diameter than the cylindrical groove 102 is processed on the basis of the cylindrical groove 102. Figure 5 , the cylindrical groove 102 is sealed by the end cover 16 through welding or other processes, the liquid inlet channel 101, the cylindrical groove 102, and the first one-way valve mounting hole 103 are connected in sequence, the liquid inlet channel 101 is arranged along the radial direction of the pump body 1, the liquid inlet channel 101 is connected to the liquid inlet pipe 14, the cylindrical groove 102 and the first one-way valve mounting hole 103 are connected, the cylindrical groove 102 and the first one-way valve mounting hole 103 are located at the center of the pump body 1 and are through-processed, the drainage groove 104 is an annular structure, the drainage groove 104 is a part of the second space, the drainage channel 105 is arranged relative to the axial direction of the pump body 1, in the direction parallel to the central axis of the pump body 1, the maximum distances of the drainage groove 104 and the drainage channel 105 relative to the central axis of the pump body 1 are equal, according to Figure 3 The present embodiment is installed in a placement manner, and the input end and the output end of the material are connected to ensure that the material completely flows out of the discharge channel 105, that is, completely flows out of the pump body 1, so as to realize the complete emptying of the material. The discharge channel 105 is connected with the discharge pipe 15, and the pump body 1 is provided with two symmetrically distributed discharge pipe installation threaded grooves on the plane where the discharge pipe 15 is installed. The discharge pipe 15 is provided with two rectangularly distributed discharge pipe threaded holes, and the arrangement manner of the two discharge pipe threaded holes is the same as the arrangement manner of the two discharge pipe installation threaded grooves. Threaded connectors such as bolts or nuts are inserted into the discharge pipe installation threaded grooves through the discharge pipe threaded holes to complete the installation of the discharge pipe 15. A first one-way valve 3 is installed inside the pump body 1, and the material enters the cylindrical groove 102 from the liquid inlet channel 101 and passes through the first one-way valve 3. The material enters the discharge channel 105 from the discharge groove 104 and is discharged through the discharge pipe 15.

[0041] refer to Figure 3 and Figure 6, a valve plate 2 and a diaphragm pressure plate 6 are fixed between the pump body 1 and the shaft body 8. The pump body 1 is provided with four shaft body mounting threaded grooves in rectangular distribution on the plane connecting the shaft body 8. The shaft body 8 is provided with four shaft body threaded holes in rectangular distribution. The arrangement of the four shaft body threaded holes is the same as the arrangement of the four shaft body mounting threaded grooves. Threaded connectors such as bolts or nuts are inserted into the shaft body mounting threaded grooves through the shaft body threaded holes. The valve plate 2 is placed on the pump body 1, and then the diaphragm pressure plate 6 is placed on the valve plate 2. The pump body 1 and the shaft body 8 press the valve plate 2 and the diaphragm pressure plate 6 to achieve fixation. The surfaces connecting the pump body 1 and the shaft body 8 are processed by other processes (such as sealing). The valve plate 2 is provided with a second one-way valve 4. The second one-way valve 4 can be one of a ball one-way valve, a diaphragm one-way valve, a lift one-way valve, and a swing one-way valve. Refer to Figure 8-10 The valve plate 2 is provided with a first liquid reservoir 21, an infusion hole 22, a second liquid reservoir 23 and a second one-way valve mounting hole 24 for mounting the second one-way valve 4. The second one-way valve 4 and the second one-way valve mounting hole 24 are provided with multiple groups and are distributed around the center line of the valve plate 2. The number of combinations of the second one-way valve 4 and the second one-way valve mounting holes 24 is the same as the number of combinations of the diaphragm fixing block 7 and the protrusion 51, and four groups are provided. The first liquid reservoir 21, the infusion hole 22, and the second liquid reservoir 23 are connected in sequence and are part of the first space. The infusion hole 22 and the second liquid reservoir 23 are distributed around the center line of the valve plate 2. The first liquid reservoir 21 is located at the center of the valve plate 2. The second one-way valve mounting holes 24 are distributed in an annular manner. The material enters the first liquid reservoir 21 through the first one-way valve 3, and reaches the second liquid reservoir 23 through the infusion hole 22, and then moves to the second one-way valve 4.

[0042] refer to Figure 1 and Fig.11 , the valve plate 2 is against the diaphragm pressure plate 6, the valve plate 2 and the diaphragm pressure plate 6 fix the diaphragm 5 therebetween, the diaphragm pressure plate 6 is provided with an annular groove 61 and a pressure plate through hole 62, the diaphragm 5 is divided into two parts, the first part is the part corresponding to the pressure plate through hole 62 in the axial direction of the diaphragm pressure plate 6, the second part is the remaining part of the diaphragm 5 except the first part, the diaphragm pressure plate 6 presses the second part of the diaphragm 5, the diaphragm fixing block 7 moves to squeeze the first part of the diaphragm 5 to produce deformation, so that the diaphragm 5 performs a periodic compression and recovery movement to generate suction, the pressure plate through holes 62 are annularly distributed, the edge of the diaphragm 5 is stuck in the annular groove 61, and the diaphragm 5 is provided with annularly distributed protrusions 51 (the diaphragm 5 is divided into two parts, the first part is the part corresponding to the pressure plate through hole 62 in the axial direction of the diaphragm pressure plate 6, the second part is the remaining part of the diaphragm 5 except the first part, and the protrusion 51 of the diaphragm 5 is located in the first part), refer to Figure 2 and Fig.12The diaphragm fixing block 7 is provided with a protrusion slot 71, the protrusion 51 is inserted into the protrusion slot 71, the diaphragm fixing block 7 is distributed around the center line of the diaphragm 5, the diaphragm 5 and a part of the diaphragm fixing block 7 are in the space of the pressure plate through hole 62, and the number of the diaphragm fixing block 7 and the protrusion 51 of the diaphragm 5 correspond, and four groups are provided.

[0043] refer to Figure 6 and Figure 7 The shaft body 8 is provided with a first mounting groove 81, a second mounting groove 82, and a third mounting groove 83 forming a stepped structure. The first bearing 10 is installed in the first mounting groove 81, and the first bearing pressure plate 11 is installed in the second mounting groove 82. The eccentric disk 9 and a part of the diaphragm fixing block 7 are located in the third mounting groove 83. A shoulder is provided at the position where the first bearing 10 is installed on the shaft body 8. The first bearing 10 is fixed to the inner wall of the shaft body 8 through the first bearing pressure plate 11. The shaft body 8 is provided with an eccentric shaft 13. The eccentric shaft 13 is connected to the first bearing 10 and extends out of the pump body 1. The eccentric shaft 13 is located inside the pump body 1 and one end thereof is provided with an eccentric disk 9 through a second bearing 12. The eccentric disk 9 is against the diaphragm fixing block 7. The eccentric disk 9 has a second bearing mounting groove 91 into which the second bearing 12 can be installed. The eccentric disk 9 is in surface contact with the diaphragm fixing block 7. The diaphragm fixing block 7 is connected to the diaphragm 5. The diaphragm fixing block 7 is distributed around the center line of the diaphragm 5. Reference Figure 1 and Figure 5 The pump body 1 is installed with an end cover 16. The position where the pump body 1 installs the end cover 16 is provided with four end cover installation thread grooves in a rectangular distribution. The end cover 16 is provided with four end cover thread holes in a rectangular distribution. The arrangement of the four end cover thread holes is the same as the arrangement of the four end cover installation thread grooves. Bolts, nuts and other threaded connectors are passed through the end cover thread holes and installed into the end cover installation thread grooves to complete the fixed installation of the end cover 16. The center line of the end cover 16 coincides with the center line of the pump body 1.

[0044] In actual operation, this embodiment follows Figure 3 The eccentric shaft 13 is installed in a placement manner, connected to the input end and the output end of the material, the eccentric shaft 13 is connected to an external motor or other rotating drive device to realize rotational motion, the eccentric shaft 13 rotates, the first bearing 10 supports the eccentric shaft 13 to operate stably, the eccentric shaft 13 drives the eccentric disk 9 to rotate, the eccentric disk 9 squeezes the diaphragm fixing block 7, the movement of the diaphragm fixing block 7 causes the diaphragm 5 to perform periodic compression and recovery motion to generate suction, the suction causes the material to move, enter the pump body 1 from the liquid inlet pipe 14, enter the cylindrical groove 102 from the liquid inlet channel 101, pass through the first one-way valve 3 into the first space formed by the pump body 1, the valve plate 2, and the diaphragm 5 (enter the first liquid storage tank 21 through the first one-way valve 3, and reach the second liquid storage tank 23 through the infusion hole 22), pass through the second one-way valve 4 into the second space formed by the pump body 1 and the valve plate 2 (enter the drainage tank 104 through the second one-way valve 4), enter the drainage pipe 15 through the drainage channel 105 and be discharged.

[0045] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A four-piston diaphragm pump capable of full draining, characterized in that: The pump comprises a liquid inlet pipe (14), a liquid discharge pipe (15), a pump body (1) and a shaft body (8); the material enters the pump body (1) and the shaft body (8) from the liquid inlet pipe (14) and is discharged from the liquid discharge pipe (15); the pump body (1) is fixedly connected to the liquid inlet pipe (14); a first one-way valve (3) is installed inside the pump body (1); a valve plate (2) and a diaphragm pressure plate (6) are fixed between the pump body (1) and the shaft body (8); a second one-way valve (4) is installed on the valve plate (2); the valve plate (2) and the diaphragm pressure plate (6) are abutted against each other; a diaphragm (5) is fixed between the valve plate (2) and the diaphragm pressure plate (6); A shaft shoulder is provided at a position where the first bearing (10) is mounted on the shaft body (8); the first bearing (10) is fixed to the inner wall of the shaft body (8) via a first bearing pressure plate (11); an eccentric shaft (13) is mounted on the shaft body (8); the eccentric shaft (13) is connected to the first bearing (10) and extends out of the pump body (1); an eccentric disk (9) is mounted on one end of the eccentric shaft (13) located inside the pump body (1) via a second bearing (12); the eccentric disk (9) abuts against a diaphragm fixing block (7); the diaphragm fixing block (7) is connected to the diaphragm (5); the material enters the pump body (1) from the liquid inlet pipe (14), flows into a first space formed by the pump body (1), the valve plate (2) and the diaphragm (5) through the first one-way valve (3), flows into a second space formed by the pump body (1) and the valve plate (2) through the second one-way valve (4), and flows into the liquid discharge pipe (15) through the axial channel of the pump body (1).

2. A fully evacuable four-piston diaphragm pump according to claim 1, characterized in that: The pump body (1) is provided with a liquid inlet channel (101), a cylindrical groove (102), a first one-way valve mounting hole (103), a liquid discharge groove (104), and a liquid discharge channel (105); the liquid inlet channel (101), the cylindrical groove (102), and the first one-way valve mounting hole (103) are sequentially connected; the liquid inlet channel (101) is arranged along the radial direction of the pump body (1); the liquid inlet channel (101) is connected to the liquid inlet pipe (14); the cylindrical groove (102) is connected to the first one-way valve mounting hole (103); 2) and the first one-way valve mounting hole (103); the cylindrical groove (102) and the first one-way valve mounting hole (103) are located at the center of the pump body (1) and are processed through; the drainage groove (104) is an annular structure; the drainage groove (104) is a part of the second space; the drainage channel (105) is arranged in an axial direction relative to the pump body (1); and the drainage channel (105) is connected to the drainage pipe (15).

3. A fully evacuable four-piston diaphragm pump according to claim 1, characterized in that: The valve plate (2) is provided with a first liquid storage tank (21), a liquid infusion hole (22), a second liquid storage tank (23), and a second one-way valve mounting hole (24) for mounting a second one-way valve (4); the first liquid storage tank (21), the liquid infusion hole (22), and the second liquid storage tank (23) are sequentially connected and form a part of the first space; the liquid infusion hole (22) and the second liquid storage tank (23) are distributed around the center line of the valve plate (2); the first liquid storage tank (21) is located at the center of the valve plate (2); the second one-way valve mounting hole (24) is distributed in an annular shape; the material enters the first liquid storage tank (21) through the first one-way valve (3).

4. A fully evacuable four-piston diaphragm pump according to claim 1, characterized in that: The diaphragm pressing plate (6) is provided with an annular groove (61) and pressing plate through holes (62), the pressing plate through holes (62) are distributed in an annular shape, and the edge of the diaphragm (5) is clamped into the annular groove (61).

5. A fully evacuable four-piston diaphragm pump according to claim 1, characterized in that: The diaphragm (5) is provided with protrusions (51) distributed in an annular manner, the diaphragm fixing block (7) is provided with protrusion slots (71), and the protrusions (51) are inserted into the protrusion slots (71).

6. A fully evacuable four-piston diaphragm pump according to claim 1 or 5, characterized in that: The diaphragm fixing blocks (7) are distributed around the center line of the diaphragm (5).

7. A fully evacuable four-piston diaphragm pump according to claim 3, characterized in that: The second one-way valve (4) and the second one-way valve mounting holes (24) are provided in multiple groups and are distributed around the center line of the valve plate (2).

8. A fully evacuable four-piston diaphragm pump according to claim 1, characterized in that: The shaft body (8) is provided with a first mounting groove (81), a second mounting groove (82), and a third mounting groove (83) forming a stepped structure; the first bearing (10) is installed in the first mounting groove (81), the first bearing pressure plate (11) is installed in the second mounting groove (82), and the eccentric disk (9) and a portion of the diaphragm fixing block (7) are located in the third mounting groove (83).

9. A fully evacuable four-piston diaphragm pump according to claim 1 or 8, characterized in that: The eccentric disk (9) has a second bearing mounting groove (91) into which the second bearing (12) can be mounted, and the eccentric disk (9) is in surface contact with the diaphragm fixing block (7).

10. A fully evacuable four-piston diaphragm pump according to claim 1 or 2, characterized in that: The pump body (1) is installed with an end cover (16), and the center line of the end cover (16) coincides with the center line of the pump body (1).

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