A hydraulic diaphragm metering pump with a pulsation-free constant flow output

Abstract

The present invention discloses a hydraulic diaphragm metering pump with a pulsation-free constant flow output, which includes a pump head, a pump body and a motor. A transmission assembly is arranged in the pump body, and the motor is used to drive the transmission assembly. The transmission assembly includes a drive shaft, an isochronous cam, a first plunger assembly and a second plunger assembly. The first plunger assembly and the second plunger assembly are respectively located on both sides of the isochronous cam. The first plunger assembly is used to control a first diaphragm assembly, and the second plunger assembly is used to control a second diaphragm assembly. By optimizing the design of the isochronous cam structure, the present invention realizes the reciprocating synchronous control of the first plunger assembly and the second plunger assembly, so that during the reciprocating movement of the first plunger assembly and the second plunger assembly, the first diaphragm chamber and the second diaphragm chamber are in a suction and discharge complementary state, and the medium flow in the first pump chamber and the second pump chamber is always in a complementary process, realizing that the medium flow transmission is always in a constant state.

Description

Technical Field

[0001] The present invention relates to the technical field of metering pumps, and particularly to a hydraulic diaphragm metering pump with a pulsation-free constant flow output. Background Art

[0002] As an ideal device for precise metering and dosing of fluids, metering pumps have been widely used in industries including pharmaceuticals, food, petrochemicals, etc. Since the working mode of metering pumps adopts a reciprocating motion mechanism, the suction and discharge processes of the liquid medium in the metering pump are carried out alternately, and during the displacement process of the plunger, its speed is constantly changing. Therefore, the instantaneous flow rate of the metering pump not only changes with time but also is output in a discontinuous pulsating form. For this reason, this pulsating form of output not only impacts the inner wall of the pipeline, causes pipeline vibration, affects the metering effect, but is more likely to corrode the inner wall of the pipeline, causing leakage of high-risk media and forming a safety hazard.

[0003] Common low-pulsation pumps are formed by two (duplex) or three (triplex) reciprocating pumps. The reciprocating pump includes a reciprocating plunger, a pump chamber whose volume increases and decreases as the plunger moves forward and backward (reciprocates), and a suction valve and a discharge valve connected to the pump chamber. When the plunger retreats (returns), the pump chamber is depressurized, and correspondingly, the suction valve opens to introduce liquid into the pump chamber. When the plunger advances (goes forward) through the lower dead center, the pump chamber is pressurized to open the discharge valve, and the liquid is transported from the opened discharge valve to the common discharge pipe. As a driving device for each reciprocating pump, a motor, a camshaft, and an eccentric driving cam are provided. The plunger of the reciprocating pump is connected to the eccentric driving cam and reciprocates as the cam rotates.

[0004] Combined with the attached Figures 16 to 19 As shown, for the commonly used reciprocating pumps in the prior art, their pulsations can be gradually reduced based on the reciprocating cross-supplementation between multiple pumps.

[0005] In the case of a duplex reciprocating pump, when the phase difference of the eccentric driving cam with respect to each reciprocating pump is set to 180°, the discharge process of one reciprocating pump and the discharge process of the other reciprocating pump are carried out complementarily. For example, the patent with the publication number CN101644244A and the patent name of pulsation-free metering pump. This metering pump includes a motor, a pump head, and a plunger. Its eccentric wheel is connected to the rotating shaft of the motor through a transmission mechanism; the eccentric wheel has an outer edge shape conforming to the characteristics of an Archimedean curve; this metering pump has two pump heads and two plungers, and each plunger corresponds to a pump head; two slide bar assemblies are oppositely arranged on both sides of the side of the eccentric wheel, and each of the adjacent ends of the two slide bar assemblies has a connecting rod passing through the slide bar assembly. The two connecting rods are connected by a connecting bolt between their corresponding ends, and the ends of the two slide bar assemblies are closely attached to the side of the eccentric wheel; the two slide bar assemblies are respectively connected to a plunger through a connecting member.

[0006] The reciprocating pumps currently available on the market generally have the characteristics of large volume, large flow rate, small pressure, and low flow accuracy control, resulting in their inability to meet the requirements of metering pumps for high-precision and high-pressure medium transportation. Summary of the Invention

[0007] In view of the above problems, the present invention aims to provide a hydraulic diaphragm metering pump with a pulsation-free constant flow output, which has higher precision and can suppress pulsation.

[0008] The technical problems solved by the present invention can be achieved by the following technical solutions:

[0009] A hydraulic diaphragm metering pump with a pulsation-free constant flow output, comprising a pump head, a pump body, and an electric motor. A transmission assembly is arranged in the pump body, and the electric motor is used to drive the transmission assembly. The transmission assembly includes a drive shaft, an isochronous cam driven by the drive shaft, a first plunger assembly and a second plunger assembly for cooperating with the isochronous cam. The first plunger assembly and the second plunger assembly are respectively located on both sides of the isochronous cam. The first plunger assembly is used to control the first diaphragm assembly, and the second plunger assembly is used to control the second diaphragm assembly. The first diaphragm assembly and the second diaphragm assembly are both arranged in the pump head. Driven by the isochronous cam, the first plunger assembly's suction and discharge control of the first diaphragm assembly and the second plunger assembly's suction and discharge control of the second diaphragm assembly form cross-complementation with each other, so that the metering pump is always in pulsation-free constant flow transmission.

[0010] A first cavity is arranged in the pump body for cooperating with the first plunger assembly. The first cavity is communicated with a first diaphragm cavity in the pump head through a first flow passage portion, and a first diaphragm assembly is arranged in the first diaphragm cavity; a second cavity is arranged in the pump body for cooperating with the second plunger assembly. The second cavity is communicated with a second diaphragm cavity in the pump head through a second flow passage portion, and a second diaphragm assembly is arranged in the second diaphragm cavity.

[0011] The first plunger assembly includes a first adjusting seat and a first plunger body which is cooperatively installed with the first adjusting seat. The other end of the first plunger body extends into the first cavity. The second plunger assembly includes a second adjusting seat and a second plunger body which is cooperatively installed with the second adjusting seat. The other end of the second plunger body extends into the second cavity. A reset base is further provided. The reset base is located on one side of the first adjusting seat. A plurality of guide rails are arranged between the reset base and the second adjusting seat. The first adjusting seat is used for sliding cooperation with the guide rails. After the first adjusting seat is driven by the isochronous cam to abut, it can move along the guide rails towards the reset base. When the isochronous cam exceeds the critical point of driving the first adjusting seat by abutting, the reset base drives the first adjusting seat to gradually complete the reset.

[0012] The reset base includes a base body and a reset spring arranged in the base body. One end of the reset spring abuts against the inner cavity wall of the base body, and the other end abuts against the first adjusting seat. A first plunger assembly part is arranged on the first adjusting seat. The reset spring is sleeved on the first plunger assembly part. The first plunger assembly part is used for cooperatively installing with one end of the first plunger body.

[0013] When the isochronous cam abuts and cooperates with the second adjusting seat, the second adjusting seat, the reset base and the first adjusting seat move towards the second cavity as a whole.

[0014] The isochronous cam can be successively and adjacently divided into an accelerating discharging arc part, a decelerating suction arc part, a constant-speed suction arc part, an accelerating suction arc part, a decelerating discharging arc part and a constant-speed discharging arc part according to the circumferential surface.

[0015] The central angle of the constant-speed discharging arc part is 135 degrees, and the central angles of the accelerating discharging arc part, the decelerating suction arc part, the constant-speed suction arc part, the accelerating suction arc part and the decelerating discharging arc part are all 45°.

[0016] A common feed valve body, a common discharge valve body and a common pump head are cooperatively arranged on the pump head. A first pump cavity and a second pump cavity are arranged in the common pump head. The first pump cavity is used for cooperating with the first diaphragm assembly, and the second pump cavity is used for cooperating with the second diaphragm assembly.

[0017] The common feed valve body includes a common feed cavity, a first feed flow channel and a second feed flow channel. The first feed flow channel communicates with the first pump cavity through a first feed check valve, and the second feed flow channel communicates with the second pump cavity through a second feed check valve. The common discharge valve body includes a common discharge cavity, a first discharge flow channel and a second discharge flow channel. The first discharge flow channel communicates with the first pump cavity through a first discharge check valve, and the second discharge flow channel communicates with the second pump cavity through a second discharge check valve.

[0018] The first diaphragm assembly includes a first diaphragm and a first valve body, and the second diaphragm assembly includes a second diaphragm and a second valve body. The first valve body is disposed in the first diaphragm cavity. The first diaphragm is used to achieve the suction and discharge of the first medium cavity, and the second diaphragm is used to suction and discharge the second medium cavity. The first medium cavity communicates with the first pump cavity through a first medium flow channel, and the second medium cavity communicates with the second pump cavity through a second medium flow channel.

[0019] Compared with the prior art, the present invention has the following beneficial effects: By optimizing the design of the constant velocity cam structure and using the cooperation of the constant velocity cam with the first adjustment seat, the second adjustment seat, and the reset base, the reciprocating synchronous control of the first plunger assembly and the second plunger assembly is realized. When the first plunger assembly and the second plunger assembly reciprocate, the first diaphragm cavity and the second diaphragm cavity are in a complementary suction and discharge state, so that the media flow in the first pump cavity and the second pump cavity is always in a complementary process, and the media flow transmission is always in a constant state.

[0020] The features of the present invention can be clearly understood by referring to the drawings of this case and the following detailed description of the preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the overall installation structure of the present invention Figure 1 ;

[0022] Figure 2 is a schematic diagram of the overall installation structure of the present invention Figure 2 ;

[0023] Figure 3 is a schematic diagram of the internal installation structure of the pump head and the pump body of the present invention;

[0024] Figure 4 is a schematic diagram of the internal installation structure of the pump body of the present invention;

[0025] Figure 5 is a schematic diagram of the overall sectional structure of the present invention Figure 1 ;

[0026] Figure 6 is a schematic diagram of the overall sectional structure of the present invention Figure 2 ;

[0027] Figure 7 is Figure 6 a partial enlarged structure diagram of part D in

[0028] Figure 8 is a schematic diagram of the overall sectional structure of the present invention Figure 3 ;

[0029] Figure 9 is a schematic diagram of the overall sectional structure of the present invention Figure 4 ;

[0030] Figure 10 It is a schematic cross-sectional structure diagram of the pump head of the present invention;

[0031] Figure 11 It is a schematic diagram of the installation structure of the pump head of the present invention Figure 1 ;

[0032] Figure 12 It is a schematic diagram of the installation structure of the pump head of the present invention Figure 2 ;

[0033] Figure 13 It is a schematic diagram of the instantaneous flow rate curve of the present invention;

[0034] Figure 14 It is a schematic diagram of the constant-speed cam structure of the present invention Figure 1 ;

[0035] Figure 15 It is a schematic diagram of the constant-speed cam structure of the present invention Figure 2 ;

[0036] Figure 16 It is a schematic diagram of the instantaneous flow rate curve of a conventional single-headed reciprocating pump in the prior art;

[0037] Figure 17 It is a schematic diagram of the instantaneous flow rate curve of a conventional double-headed reciprocating pump in the prior art;

[0038] Figure 18 It is a schematic diagram of the instantaneous flow rate curve of a conventional three-headed reciprocating pump in the prior art;

[0039] Figure 19 It is a schematic diagram of the instantaneous flow rate curve of a conventional five-headed reciprocating pump in the prior art. Specific embodiments

[0040] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below with reference to specific illustrations.

[0041] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "one end", "the other end", "outer side", "upper", "inner side", "horizontal", "coaxial", "central", "end part", "length", "outer end", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0042] Combined with the attached Figures 1 to 19As shown, this embodiment discloses a hydraulic diaphragm metering pump with a pulsation-free constant flow output, including a pump head 300, a pump body 200 and a motor 100. A transmission assembly is arranged in the pump body 200, the motor 100 is used to drive the transmission assembly, and the pump head 300 is used to realize the transmission of the medium flow.

[0043] Among them, the transmission assembly includes a drive shaft 410, a constant velocity cam 400 driven by the drive shaft 410, a first plunger assembly 500 and a second plunger assembly 600 for cooperating with the constant velocity cam 400, wherein the other end of the drive shaft 410 is usually matched with a transmission gear 420, and the transmission gear 420 is used to cooperate with the gear ring part in the input shaft 110, wherein the transmission gear 420 is independently set, which can increase the accuracy of the transmission gear 420, and combined with the power output of the input shaft 110, increase the transmission stability of the constant velocity cam 400, and the input shaft 110 is usually used to cooperate with the motor 100.

[0044] In combination with the above, the first plunger assembly 500 and the second plunger assembly 600 are respectively located on both sides of the constant velocity cam 400, and the constant velocity cam 400 is used to drive the first plunger assembly 500 and the second plunger assembly 600; Figure 15 and Figure 16 As shown, the structure of the constant velocity cam 400 is optimized. The constant velocity cam 400 can be divided into an accelerating discharge arc portion 401, a decelerating material suction arc portion 402, a uniform material suction arc portion 403, an accelerating material suction arc portion 404, a decelerating material discharge arc portion 405 and a uniform material discharge arc portion 406 in sequence according to the circumferential surface. The center angle of the uniform material discharge arc portion 406 is 135 degrees, and the center angles of the accelerating discharge arc portion 401, the decelerating material suction arc portion 402, the uniform material suction arc portion 403, the accelerating material suction arc portion 404 and the decelerating material discharge arc portion 405 are all 45 degrees. Figure 13 As shown, the instantaneous flow curve of the pulsation-free pump is displayed correspondingly. The constant velocity cam 400 is used to realize the cooperation with the first plunger assembly 500 and the second plunger assembly 600 in the reciprocating motion, and they can complement each other. For example, when the accelerating discharge arc portion 401 in the constant velocity cam 400 is in conflict with the first plunger assembly 500, the accelerated discharge is realized in the first pump chamber 350. Synchronously, the decelerating discharge arc portion 405 in the constant velocity cam 400 is in conflict with the second plunger assembly 600, so that the decelerated discharge is realized in the second pump chamber 360, and so on, so that the metering pump as a whole is always at a constant flow rate.

[0045] Combined with Figure 13As shown, the first plunger assembly 500 combines with the first diaphragm assembly 330 to achieve the corresponding instantaneous flow curve A for the first pump chamber 350, and the second plunger assembly 600 combines with the second diaphragm assembly 360 to complete the corresponding instantaneous flow curve B. Both can achieve cross-complementation during the discharging process and the feeding process respectively, and after cross-complementation, an instantaneous flow synthesis curve C is formed. When the instantaneous flow curve B enters the uniform discharging or feeding state, the instantaneous flow curve A enters the inactive state at the same time, that is, the corresponding inlet check valve or outlet check valve is in the closed state, so that a single pump chamber in the first pump chamber 350 or the second pump chamber 360 can achieve uniform discharging or feeding.

[0046] In the specific structure, the first plunger assembly 500 is used to control the first diaphragm assembly 330, and the second plunger assembly 600 is used to control the second diaphragm assembly 340. Both the first diaphragm assembly 330 and the second diaphragm assembly 340 are arranged in the pump head 300. The pump head 300 adopts an integrated structure design to optimize the overall structure, making the metering pump more optimized as a whole and facilitating high-pressure delivery and high-precision delivery. Driven by the constant-speed cam 400, the first plunger assembly 500's suction and discharge control of the first diaphragm assembly 330 and the second plunger assembly 600's suction and discharge control of the second diaphragm assembly 340 form cross-complementation with each other, so that the metering pump is always in a non-pulsating constant-flow transmission state.

[0047] Among them, a first cavity 201 is arranged in the pump body 200. The first cavity 201 is used to cooperate with the first plunger assembly 500. The first cavity 201 communicates with the first diaphragm cavity 301 in the pump head 200 through the first flow channel part 210. A first diaphragm assembly 330 is arranged in the first diaphragm cavity 301. A second cavity 202 is arranged in the pump 200. The second cavity 202 is used to cooperate with the second plunger assembly 600. The second cavity 202 communicates with the second diaphragm cavity 302 in the pump head 300 through the second flow channel part 220. A second diaphragm assembly 340 is arranged in the second diaphragm cavity 302. Among them, the first cavity 201, the first flow channel part 210, and the first diaphragm cavity 301 communicate with each other and are all used to fill hydraulic oil. The second cavity 202, the second flow channel part 220, and the second diaphragm cavity 302 communicate with each other and are all used to fill hydraulic oil. Among them, a first flow channel and a second flow channel are respectively arranged in the first flow channel part 210 and the second flow channel part 220 to facilitate the circulation of hydraulic oil.

[0048] Combined with the above, the first plunger assembly 500 includes a first adjusting base 510 and a first plunger body 520 installed in cooperation with the first adjusting base 510. The other end of the first plunger body 520 extends into the first cavity 201. The second plunger assembly 600 includes a second adjusting base 610 and a second plunger body 620 installed in cooperation with the second adjusting base 610. The other end of the second plunger body 620 extends into the second cavity 202. A reset base 700 is further provided. The reset base 700 is located on one side of the first adjusting base 510. A plurality of guide rails 730 are provided between the reset base 700 and the second adjusting base 610. In a specific embodiment, the number of the guide rails 730 can be 4, which are arranged at the four corner positions respectively. The first adjusting base 510 is used for sliding cooperation with the guide rails 730. After the first adjusting base 510 is driven by the constant velocity cam 400 to abut, it can move along the guide rails 730 towards the reset base 700. When the constant velocity cam 400 exceeds the critical point of driving the first adjusting base 510 by abutting, the reset base 700 drives the first adjusting base 510 to gradually complete the reset.

[0049] Optimize the structures of the first adjusting base 510, the second adjusting base 610 and the reset base 700. Use the constant velocity cam 400 to abut and drive the first adjusting base 510, so that the first adjusting base 510 can push the first plunger body 520. Utilize the structural design that the first adjusting base 510 can move along the guide rails 730, and the second adjusting base 610 and the reset base 700 are in an overall synchronous state. Therefore, the first adjusting base 510 can move relative to the second adjusting base 610 and the reset base 700. Combined with the corresponding structure of the constant velocity cam 400, good cross-complementation can be achieved.

[0050] In a specific structure, the reset base 700 includes a base body 710 and a reset spring 720 arranged in the base body 710. One end of the reset spring 720 abuts against the inner cavity wall of the base body 710, and the other end abuts against the first adjusting base 510. A first plunger assembly part 511 is provided on the first adjusting base 510. The reset spring 720 is sleeved on the first plunger assembly part 511. The first plunger assembly part 511 is used for installing and cooperating with one end of the first plunger body 520. When the constant velocity cam 400 abuts and cooperates with the second adjusting base 610, the second adjusting base 610, the reset base 700 and the first adjusting base 510 as a whole move towards the second cavity 202. Among them, a second plunger assembly part 611 is usually provided on the second adjusting base 610. The second plunger assembly part 611 is used for installing and cooperating with one end of the second plunger body 620.

[0051] Combined with the above, a common feed valve body 310, a common discharge valve body 320 and a common pump head 301 are cooperatively provided on the pump head 300. The common feed valve body 310 is used to complete the suction of the medium, and the common discharge valve body 320 is used to complete the discharge of the medium. Usually, the flow channel cavity in the common feed valve body 310 is larger than the flow channel cavity in the common discharge valve body 320; a first pump chamber 350 and a second pump chamber 360 are arranged in the common pump head 301. The first pump chamber 350 and the second pump chamber 360 are independent of each other. The first pump chamber 350 is used to cooperate with the first diaphragm assembly 330, and the second pump chamber 360 is used to cooperate with the second diaphragm assembly 340; the common feed valve body 310 includes a common feed cavity 311, a first feed flow channel 312 and a second feed flow channel 313. The ends of the first feed flow channel 312 and the second feed flow channel 313 are both communicated with the common feed cavity 311. The first feed flow channel 312 is communicated with the first pump chamber 350 through a first feed check valve 314, and the second feed flow channel 313 is communicated with the second pump chamber 360 through a second feed check valve 315; the common discharge valve body 320 includes a common discharge cavity 321, a first discharge flow channel 322 and a second discharge flow channel 323. The ends of the first discharge flow channel 322 and the second discharge flow channel 323 are both communicated with the common discharge cavity 321. The first discharge flow channel 322 is communicated with the first pump chamber 350 through a first discharge check valve 324, and the second discharge flow channel 323 is communicated with the second pump chamber 360 through a second discharge check valve 325.

[0052] Among them, in this embodiment, the structure of the pump head 300 is optimized. By designing the common feed valve body 310, the common discharge valve body 320 and the common pump head 301, the pipeline reflux space can be shortened, the influence of fluid inertia on pulsation and the influence of the compressibility of the fluid at high pressure on pulsation can be reduced.

[0053] Combined with the above, the first diaphragm assembly 330 includes a first diaphragm 332 and a first valve body 331, and the second diaphragm assembly 340 includes a second diaphragm 342 and a second valve body 341. The first valve body 331 is arranged in the first diaphragm cavity 301. The first diaphragm 332 is used to realize the suction and discharge of the first medium inner cavity 351, and the second diaphragm 342 is used to suck and discharge the second medium inner cavity 361. The first medium inner cavity 351 is communicated with the first pump chamber 350 through a first medium flow channel 352, and the second medium inner cavity 361 is communicated with the second pump chamber 360 through a second medium flow channel 362; through optimization design, by using the suction and discharge complementary effects between the first diaphragm 332 and the second diaphragm 342 and combining the corresponding instantaneous flow rate curves, when the pump head 300 feeds, the total feed amounts of the first feed flow channel 210 and the second feed flow channel 220 are always kept at the same flow rate; when discharging, in combination with the common discharge valve body, by using the first discharge flow channel 210 and the second discharge flow channel 220, the total discharge amounts are always kept at the same flow rate, so as to realize the constant flow rate transmission of the metering pump.

[0054] Through optimizing the design of the constant velocity cam structure, the present invention utilizes the cooperation of the constant velocity cam with the first adjusting seat, the second adjusting seat and the reset base to realize the reciprocating synchronous control of the first plunger assembly and the second plunger assembly, so that in the reciprocating motion of the first plunger assembly and the second plunger assembly, the first diaphragm chamber and the second diaphragm chamber are in suction and discharge complementarity, and the media flow in the first pump chamber and the second pump chamber is always in a complementary process, realizing that the media flow transmission is always in a constant state.

[0055] The above is only the preferred embodiment of the present invention, and does not impose any formal restrictions on the invention. Any simple modification, equivalent change or modification made to the above embodiments based on the technical principle of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A hydraulic diaphragm metering pump with a pulsation-free constant flow output, comprising a pump head, a pump body and a motor. A transmission assembly is arranged in the pump body, and the motor is used to drive the transmission assembly. Characterized in that: The transmission assembly includes a drive shaft, a constant-speed cam driven by the drive shaft, a first plunger assembly and a second plunger assembly for cooperating with the constant-speed cam. The first plunger assembly and the second plunger assembly are respectively located on both sides of the constant-speed cam. The first plunger assembly is used to control a first diaphragm assembly, and the second plunger assembly is used to control a second diaphragm assembly. The first diaphragm assembly and the second diaphragm assembly are both arranged in the pump head. Driven by the constant-speed cam, the suction and discharge control of the first diaphragm assembly by the first plunger assembly and the suction and discharge control of the second diaphragm assembly by the second plunger assembly form cross-complementation with each other, so that the metering pump is always in pulsation-free constant flow transmission. A first cavity is arranged in the pump body for cooperating with the first plunger assembly. The first plunger assembly includes a first adjusting seat and a first plunger body cooperatively installed with the first adjusting seat. The other end of the first plunger body extends into the first cavity. The second plunger assembly includes a second adjusting seat and a second plunger body cooperatively installed with the second adjusting seat. The other end of the second plunger body extends into the second cavity. A reset base is also provided. The reset base is located on one side of the first adjusting seat. A plurality of guide rails are arranged between the reset base and the second adjusting seat. The first adjusting seat is used for sliding cooperation with the guide rails. After being driven by the constant-speed cam to abut, the first adjusting seat can move along the guide rails towards the reset base. When the constant-speed cam exceeds the critical point of abutting and driving with the first adjusting seat, the reset base drives the first adjusting seat to gradually complete the reset. The reset base includes a base body and a reset spring arranged in the base body. One end of the reset spring abuts against the inner cavity wall of the base body, and the other end abuts against the first adjusting seat. A first plunger assembly part is arranged on the first adjusting seat, and the reset spring is sleeved on the first plunger assembly part. The first plunger assembly part is used for cooperating with one end of the first plunger body for installation.

2. The hydraulic diaphragm metering pump with a pulsation-free constant flow output according to claim 1, Characterized in that: The first cavity is communicated with a first diaphragm cavity in the pump head through a first flow channel part. A first diaphragm assembly is arranged in the first diaphragm cavity. A second cavity is arranged in the pump body for cooperating with the second plunger assembly. The second cavity is communicated with a second diaphragm cavity in the pump head through a second flow channel part. A second diaphragm assembly is arranged in the second diaphragm cavity.

3. The hydraulic diaphragm metering pump with a pulsation-free constant flow output according to claim 1, Characterized in that: When the constant-speed cam abuts and cooperates with the second adjusting seat, the second adjusting seat, the reset base and the first adjusting seat as a whole move towards the second cavity direction.

4. A hydraulic diaphragm metering pump with a pulsation-free constant flow output according to claim 3, characterized in that: The constant-speed cam can be successively and adjacently divided into an accelerating discharge arc portion, a decelerating suction arc portion, a constant-speed suction arc portion, an accelerating suction arc portion, a decelerating discharge arc portion, and a constant-speed discharge arc portion according to the circumferential surface.

5. A hydraulic diaphragm metering pump with a pulsation-free constant flow output according to claim 4, characterized in that: The central angle of the constant-speed discharge arc portion is 135 degrees, and the central angles of the accelerating discharge arc portion, the decelerating suction arc portion, the constant-speed suction arc portion, the accelerating suction arc portion, and the decelerating discharge arc portion are all 45°.

6. A hydraulic diaphragm metering pump with a pulsation-free constant flow output according to any one of claims 1 to 5, characterized in that: A common feed valve body, a common discharge valve body, and a common pump head are cooperatively provided on the pump head. A first pump chamber and a second pump chamber are provided in the common pump head. The first pump chamber is used to cooperate with a first diaphragm assembly, and the second pump chamber is used to cooperate with a second diaphragm assembly.

7. A hydraulic diaphragm metering pump with a pulsation-free constant flow output according to claim 6, characterized in that: The common feed valve body includes a common feed cavity, a first feed flow channel, and a second feed flow channel. The first feed flow channel communicates with the first pump chamber through a first feed check valve, and the second feed flow channel communicates with the second pump chamber through a second feed check valve; the common discharge valve body includes a common discharge cavity, a first discharge flow channel, and a second discharge flow channel. The first discharge flow channel communicates with the first pump chamber through a first discharge check valve, and the second discharge flow channel communicates with the second pump chamber through a second discharge check valve.

8. A hydraulic diaphragm metering pump with a pulsation-free constant flow output according to claim 7, characterized in that: The first diaphragm assembly includes a first diaphragm and a first valve body. The second diaphragm assembly includes a second diaphragm and a second valve body. The first valve body is arranged in the first diaphragm cavity. The first diaphragm is used to realize the suction and discharge of the first medium inner cavity, and the second diaphragm is used to suction and discharge the second medium inner cavity. The first medium inner cavity communicates with the first pump chamber through a first medium flow channel, and the second medium inner cavity communicates with the second pump chamber through a second medium flow channel.

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