CN111043002B

CN111043002B - Reciprocating plunger pump

Info

Publication number: CN111043002B
Application number: CN201911386690.8A
Authority: CN
Inventors: 不公告发明人
Original assignee: Individual
Current assignee: DONGYING SHENGCHANG PETROLEUM MACHINERY CO LTD
Priority date: 2019-12-29
Filing date: 2019-12-29
Publication date: 2021-07-30
Anticipated expiration: 2039-12-29
Also published as: CN111043002A

Abstract

The invention belongs to the technical field of reciprocating plunger pumps. The invention discloses a reciprocating plunger pump which comprises a shell, a piston cylinder, a first plunger and a piston, wherein the shell is provided with a P port connected with an oil inlet pipe, a T1 port and a T2 port connected with an oil outlet pipe, the piston cylinder is positioned in the shell, the piston is positioned in the piston cylinder, the piston can axially reciprocate under the action of high-pressure oil, the piston cylinder can axially reciprocate relative to the shell under the action of the high-pressure oil, so that two sides of the piston are respectively communicated with the high-pressure oil alternately, and the reciprocating movement of automatic reversing of a hydraulic cylinder is realized. The reciprocating plunger pump can automatically change direction and reciprocate under the drive of hydraulic pressure, has simple and compact structure, low manufacturing cost and high integration level, can omit the use of a change valve, does not need electric control, avoids unstable factors of electric appliances, can work for a long time and has long service life.

Description

Reciprocating plunger pump

Technical Field

The invention belongs to the technical field of reciprocating pumps, and particularly relates to a reciprocating plunger pump.

Background

With the large-scale application of large mechanical equipment, the hydraulic driving technology is increasingly mature in the technical field of fluid compression application. The traditional reciprocating plunger pump adopts a crank-connecting rod mechanism to realize the reciprocating motion of a piston in a cylinder body so as to compress fluid, and the reciprocating plunger pump in the mode has large and unstable output pulse and is easy to block under severe working conditions.

In addition, the reversing valve for realizing the reciprocating motion of the piston in the existing hydraulic reciprocating plunger pump mostly adopts the cooperation of an electromagnetic reversing valve and a displacement sensor to control the reversing, and controls the sensor by a proximity switch. Therefore, the reversing is not only unstable and unreliable, but also the control circuit part of the reversing device adopts circuit board control, and the circuit board is a non-standard part and is difficult to manufacture and process, so that the circuit board is difficult to repair after being damaged, and the subsequent use and maintenance cost is increased. Meanwhile, if the existing reversing device is continuously electrified for a long time, small devices are easily damaged, the requirement of long-time electrification cannot be met, and the service efficiency is influenced to a certain extent.

Disclosure of Invention

In order to solve the problems of the conventional reciprocating plunger pump, the invention provides a reciprocating plunger pump with a brand-new structural form. The reciprocating plunger pump comprises a shell, a piston cylinder, a piston and a first plunger; a first working chamber for outputting fluid is arranged in the shell, a P port, a T1 port, a T2 port, a first liquid inlet hole and a first liquid outlet hole are formed in the shell, the P port is connected with an oil inlet pipe, and a T1 port and a T2 port are connected with an oil outlet pipe;

the piston cylinder is positioned in the shell and can perform axial reciprocating movement relative to the shell; the piston cylinder is provided with a first oil hole and a second oil hole which are distributed along the axial direction, and the first oil hole and the second oil hole are communicated with a P port, a T1 port and a T2 port alternately; when the first oil hole is communicated with the P port, the second oil hole is communicated with a T2 port, and when the second oil hole is communicated with the P port, the first oil hole is communicated with a T1 port; a first control cavity, a second control cavity and an oil return cavity which are independent are arranged between the piston cylinder and the shell, the first control cavity and the second control cavity are respectively positioned at two ends of the piston cylinder, the sectional area of the first control cavity is larger than that of the second control cavity, the oil return cavity is communicated with a T1 port, the second control cavity is communicated with a P port, and the first control cavity is selectively communicated with the P port and the T1 port;

the piston is positioned in the piston cylinder and can perform axial reciprocating movement relative to the piston cylinder; the piston divides the inside of the piston cylinder into a first control chamber and a second control chamber in an axial direction, and the first control chamber and the second control chamber communicate with the first oil hole and the second oil hole, respectively; the first plunger is positioned in the first working chamber and is fixedly connected with the piston;

when the piston moves to an axial terminal position relative to the piston cylinder, the piston cylinder moves axially relative to the housing, and the communication relationship switching between the first oil hole and the second oil hole and the P port, the T1 port and the T2 port is completed.

Preferably, the housing is provided with a first oil path, a second oil path, a third oil path, a fourth oil path and a fifth oil path; a first annular groove is formed in the first plunger;

one end of the first oil way is communicated with the port P, and the other end of the first oil way is selectively communicated with the first annular groove; the second oil way is used for communicating the port P with the second control cavity; one end of the third oil way is communicated with the first control cavity, and the other end of the third oil way is communicated with the first annular groove; one end of the fourth oil way is communicated with the third oil way, and the other end of the fourth oil way is communicated with the first control chamber; one end of the fifth oil way is communicated with a T1 port, and the other end of the fifth oil way is selectively communicated with the first annular groove;

when the piston moves to the terminal position of the first control chamber, the first oil path is communicated with the first annular groove; when the piston moves to the terminal position of the second control chamber, the fifth oil passage is communicated with the first annular groove.

Further preferably, a damping hole is formed in the fourth oil path.

Further preferably, the piston is in a step structure, and the steps on two sides are respectively part of the first control chamber and the second control chamber.

Preferably, the shell is provided with a first connecting groove; the first connecting groove is located between the shell and the piston cylinder, is an annular groove distributed along the axial direction, and is communicated with the port P.

Preferably, a second connecting groove is formed in the shell; the second connecting groove is located between the shell and the piston cylinder, is an annular groove arranged along the axial direction, and is communicated with a T1 port and an oil return cavity.

Preferably, a third connecting groove is formed in the shell; the third connecting groove is an annular groove arranged along the axial direction and is communicated with a port T2.

Preferably, the shell adopts a split structure, a left end cover and a right end cover are respectively arranged at two ends of the shell, the left end cover is provided with a left convex column extending into the piston cylinder, and a right convex column extending into the piston cylinder is arranged in the right end cover; a first control chamber is formed between the left convex column and the piston in the piston cylinder, and a second control chamber is formed between the right convex column and the piston in the piston cylinder.

Preferably, the piston cylinder comprises an expanding section and a main body section from left to right, the diameter of the expanding section is larger than that of the main body section, a first control cavity is formed between the expanding section and the left end cover, an oil return cavity is formed between the right end face of the expanding section and the shell, and a second control cavity is formed between the right end face of the main body section and the right end cover.

Preferably, the liquid distributor further comprises a second plunger, a second working chamber, a second liquid inlet hole and a second liquid outlet hole are further formed in the shell, and the second plunger is located in the second working chamber and fixedly connected with the piston.

Compared with the reciprocating pump with the existing structure, the reciprocating plunger pump has the following beneficial technical effects:

1. in the invention, the shell is respectively provided with a P port connected with the oil inlet pipe, and a T1 port and a T2 port connected with the oil outlet pipe, and the P port, the T1 port and the T2 port are alternately communicated with the control chambers at two sides of the piston, so that the piston is driven by high-pressure oil to axially reciprocate, and the first plunger and the second plunger are driven to perform reciprocating liquid suction and liquid discharge. Meanwhile, when the piston moves to the terminal position of the control chamber, the high-pressure oil at the position of the P port is used for driving the piston cylinder to axially move relative to the shell, so that the switching of the hydraulic acting force alternately applied to the two sides of the piston by the high-pressure oil is achieved, the piston is driven to axially reciprocate and alternately move, and the purposes of reciprocating liquid suction and liquid discharge are achieved. Therefore, the automatic reciprocating movement of the piston can be realized under the control of the hydraulic oil in the reciprocating plunger pump, and the reciprocating action condition that the existing hydraulically-driven reciprocating pump can only realize by a reversing valve is changed.

2. In the invention, the oil passages, the oil holes and the annular grooves which are mutually associated are arranged on the shell, the piston cylinder and the piston, so that the alternating communication switching of the P port, the T1 port and the T2 port and the control chambers at two sides of the piston is completed in the relative axial movement process of the piston cylinder relative to the shell. Therefore, the requirements on the use and control of the electromagnetic reversing valve in the existing automatic reversing process can be completely omitted, the cost and the control complexity are reduced, and the utilization rate of parts is improved, the volume of the whole hydraulic cylinder is reduced, the use amount of the parts is reduced by respectively arranging a plurality of structures with different functions on the shell, the piston cylinder and the piston, so that the high integration degree of the whole reciprocating plunger pump is realized.

Drawings

FIG. 1 is a schematic structural diagram illustrating a process of moving a piston toward a first control chamber in a reciprocating plunger pump according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of the reciprocating plunger pump of the embodiment after the piston moves to the terminal position of the first control chamber and the reversing is completed.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to the accompanying drawings and embodiments.

Referring to fig. 1, the reciprocating plunger pump of the present embodiment includes a housing 1, a piston cylinder 2, a piston 3, a first plunger 41, and a second plunger 42. Wherein, along the axis direction, the first plunger 41 and the second plunger 42 are respectively and fixedly connected at two ends of the piston 3, and the piston 3 drives the first plunger 41 and the second plunger 42 to perform axial synchronous movement.

The shell 1 is a hollow structure, and the shell 1 is provided with a port P, a port T1, a port T2, a first liquid inlet hole 15, a first liquid outlet hole 16, a second liquid inlet hole 17 and a second liquid outlet hole 18. Wherein, P mouth is connected with advancing oil pipe, and T1 mouth and T2 mouth are connected with an oil pipe respectively, through install corresponding logical liquid check valve respectively in first feed liquor hole 15, first liquid hole 16, second feed liquor hole 17 and second liquid hole 18 to realize the corresponding one-way feed liquor in each hole and one-way flowing back function.

The housing 1 is further provided with a first working chamber 10 and a second working chamber 19 inside, a first plunger 41 being slidably connected in the first working chamber 10, and a second plunger 42 being slidably connected in the second working chamber 19.

The piston cylinder 2 is located inside the housing 1, and the outer surface of the piston cylinder 2 is in contact with the inner surface of the housing 1 and can perform reciprocating movement in the axial direction with respect to the housing 1. First and

second oil holes

21 and 22 are provided in the piston cylinder 2 so as to be distributed in the axial direction, and the first and

second oil holes

21 and 22 are alternately communicated with the ports P, T1 and T2. When the first oil hole 21 communicates with the port P, the second oil hole 22 communicates with the port T2; when the second oil hole 22 communicates with the port P, the first oil hole 21 communicates with the port T1. An independent first control cavity 51, a second control cavity 52 and an oil return cavity 53 are arranged between the piston cylinder 2 and the housing 1, the first control cavity 51 and the second control cavity 52 are respectively positioned at two ends of the piston cylinder 2, the sectional area of the first control cavity 51 is larger than that of the second control cavity 52, the oil return cavity 53 is communicated with a port T1, the second control cavity 52 is communicated with a port P, and the first control cavity 51 is selectively communicated with the port P and the port T1.

The piston 3 is located inside the piston cylinder 2 and is axially reciprocable relative to the piston cylinder 2. The piston 3 divides the interior of the piston cylinder 2 into a first control chamber 23 and a second control chamber 24 in the axial direction, and the first control chamber 23 and the second control chamber 24 are held in communication with the first oil hole 21 and the second oil hole 22, respectively.

When the port P is communicated with the first oil hole 21, high-pressure oil in the oil inlet pipe is guided to the first control chamber 23, meanwhile, the second oil hole 22 is communicated with the port T2, and oil in the second control chamber 24 is guided to the oil outlet pipe, so that the piston 3 moves towards the second control chamber 24 under the action of the high-pressure oil in the first control chamber 23, the first working chamber 10 absorbs the liquid, and the second working chamber 19 discharges the liquid. When the piston 3 moves to the end position of the second control chamber 24, the piston cylinder 2 moves axially relative to the housing 1, the port P is switched to communicate with the second oil hole 22, the first oil hole 21 is switched to communicate with the port T1, and the piston 3 starts to be driven in the reverse direction toward the first control chamber 23.

When the port P is communicated with the second oil hole 22, high-pressure oil in the oil inlet pipe is guided to the second control chamber 24, meanwhile, the first oil hole 21 is communicated with the port T1, and oil in the first control chamber 23 is guided to the oil outlet pipe, so that the piston 3 moves towards the first control chamber 23 under the action of the high-pressure oil in the second control chamber 24, the liquid drainage of the first working chamber 10 is realized, and the liquid suction of the second working chamber 19 is realized. When the piston 3 moves to the end position of the first control chamber 23, the piston cylinder 2 moves axially relative to the housing 1, switching the port P to communicate with the first oil hole 21 and the second oil hole 22 to communicate with the port T2, thereby starting to reversely drive the piston 3 to move in the direction of the second control chamber 24.

Referring to fig. 1, the casing is provided with a first oil passage 11, a second oil passage 12, a third oil passage 13, a fourth oil passage 14, and a fifth oil passage 15; the first plunger 41 is provided with a first annular groove 31; one end of the first oil path 11 is communicated with the port P, and the other end is selectively communicated with the first annular groove 31; the second oil passage 12 is used for communicating the port P with the second control chamber 52; one end of the third oil passage 13 communicates with the first control chamber 51, and the other end communicates with the first annular groove 31; one end of the fourth oil passage 14 communicates with the third oil passage 13, and the other end communicates with the first control chamber 23; one end of the fifth oil path 15 is communicated with a port T1, and the other end is selectively communicated with the first annular groove 31; when the piston 3 moves to the end position of the first control chamber 23, the first oil passage 11 communicates with the first annular groove 31; when the piston 3 moves to the end position of the second control chamber 24, the fifth oil passage 15 communicates with the first annular groove 31.

In the present embodiment, switching of the communication relationship among the oil passages is accomplished by a plurality of oil passages arranged in an axial relationship and by axial movement between the piston cylinder relative to the housing, and switching of the communication relationship among the P port, the T1 port, and the T2 port and the first control chamber and the second control chamber is achieved. Similarly, in another embodiment, the oil passages may be arranged in a circumferential relationship, and the communication relationship among the oil passages may be switched by the rotation of the piston cylinder relative to the housing in the circumferential direction, so that the communication relationship among the P port, the T1 port, and the T2 port, and the first control chamber and the second control chamber may be switched.

As shown in fig. 1, one orifice 6 is provided in the fourth oil passage 14. At this time, by means of the damping effect of the damping hole on the oil passing through the fourth oil passage, i.e. the damping effect on the oil flowing between the third oil passage 13 and the first control chamber 23, not only the oil in the first oil passage can rapidly enter the first control chamber through the first annular groove and the third oil passage, the establishment speed of the oil pressure in the first control chamber is increased, so that the piston cylinder can rapidly move axially relative to the housing, thereby increasing the reversing speed of the piston, but also when the piston moves towards the second control chamber, the high-pressure oil flowing from the first control chamber to the first control chamber through the fourth oil passage and the third oil passage can be stabilized, the acting force of the high-pressure oil in the first control chamber on the piston cylinder and pointing to the direction of the second control chamber is maintained, the piston cylinder is fixed at the terminal position of the second control chamber, and the piston is ensured to move towards the second control chamber, the first oil hole is stably connected with the port P, the second oil hole is stably connected with the port T2, and the stability and the reliability of the hydraulic cylinder in the working process are improved.

As shown in fig. 1, in the present embodiment, the piston 3 has a stepped structure, and the steps on both sides are part of the first control chamber 23 and the second control chamber 24, respectively. Therefore, when the piston moves to the terminal position along the axial direction, the first control chamber and the second control chamber can be continuously kept between the piston and the shell by virtue of the steps on the two sides of the piston, so that high-pressure oil is quickly introduced, acting force for driving the piston in the opposite direction is quickly established, the reaction speed of the piston moving in the opposite direction along the axial direction is increased, and the reversing speed of the reciprocating motion of the hydraulic cylinder is increased.

As shown in fig. 1, the housing 1 is further provided with a first connecting groove 191. The first connecting groove 191 is in the form of an annular groove structure arranged in the axial direction and is communicated with the port P. Therefore, in the process of axial movement of the piston cylinder, even if the piston cylinder rotates in the circumferential direction, accurate and quick communication between the P port and the first oil hole or the second oil hole can be guaranteed, and the stability and the reliability of the hydraulic cylinder in the working process are guaranteed.

As shown in fig. 1, a second connection groove 192 and a third connection groove 193 are respectively provided on the housing 1. The second connecting groove 192 and the third connecting groove 193 are both in the form of annular groove structures and are located between the housing 1 and the piston cylinder 2, wherein the second connecting groove 192 is communicated with the port T1 and the oil return chamber 53, and the third connecting groove 193 is communicated with the port T2. Therefore, even if the piston rotates in the circumferential direction during the axial movement process, accurate and quick communication between the T1 port and the first oil hole and between the T2 port and the second oil hole can be ensured, and the stability and the reliability of the hydraulic cylinder during the working process are ensured.

In addition, as shown in fig. 1, in this embodiment, the housing 1 is a split structure, and the two ends of the housing are respectively a left end cover 4 and a right end cover 5 which are detachable, the left end cover 4 is provided with a left convex pillar extending into the piston cylinder 2, and the right end cover 5 is provided with a right convex pillar extending into the piston cylinder 2; a first control chamber 23 is formed in the piston cylinder 2 between the left boss and the piston 3, and a second control chamber 24 is formed between the right boss and the piston 3. Therefore, the whole shell is convenient to process and manufacture, particularly relevant oil ways, so that the processing difficulty and cost are reduced, the disassembly is convenient, and the assembly efficiency and the maintenance convenience are improved.

Referring to fig. 1, the piston cylinder 2 includes an expanding section and a main body section from left to right, the diameter of the expanding section is larger than that of the main body section, a first control cavity 51 is formed between the expanding section and the left end cover 4, an oil return cavity 53 is formed between the right end surface of the expanding section and the housing 1, and a second control cavity 52 is formed between the right end surface of the main body section and the right end cover 5. Thus, when the cross-sectional area of the first control chamber 51 is made larger than that of the second control chamber 52, and the pressures in the first control chamber 51 and the second control chamber 52 are equal, the piston cylinder 2 moves toward the second control chamber 24 due to the difference in the cross-sectional areas; when the pressure in the first control chamber 51 is equal to the pressure at the port T1, the second control chamber pressure is equal to the pressure at the port P, and the piston cylinder 2 moves in the direction of the first control chamber 23.

Referring to fig. 1 to 2, when the reciprocating plunger pump of this embodiment works, the P port is connected to the oil inlet pipe, the T1 port and the T2 port are connected to the oil outlet pipe, the first liquid inlet hole 15 and the second liquid inlet hole 17 are communicated to the liquid suction port, the first liquid outlet hole 16 and the second liquid outlet hole 18 are communicated to the liquid outlet, and the specific working process is as follows:

when the piston 3 moves towards the second control chamber 24, as shown in fig. 2, high-pressure oil in the oil inlet pipe flows into the first control chamber 23 sequentially through the port P, the first connecting groove 191 and the first oil hole 21, and simultaneously oil in the second control chamber 24 flows into the oil outlet pipe sequentially through the second oil hole 22, the third connecting groove 193 and the port T2, so that the piston 3 moves towards the second control chamber 24 under the action of the pressure difference between the oil on the two sides of the first control chamber 23 and the second control chamber 24, the second piston 42 discharges liquid in the second working chamber 19 through the second liquid outlet 18, and the liquid is sucked into the first working chamber 10 through the first liquid inlet 15.

In the above process, the high-pressure oil in the first control chamber 23 sequentially flows to the first control chamber 51 through the damping hole 6, the fourth oil passage 14 and the third oil passage 13, and the pressure in the first control chamber 51 and the pressure in the second control chamber 52 are both equal to the pressure at the port P, so that the piston cylinder 2 is fixed at the terminal position of the second control chamber 52 under the action of the difference in the areas of the first control chamber 51 and the second control chamber 52, the stable communication state of the first connecting groove 191 and the first oil hole 21 and the stable communication state of the second oil hole 22 and the third connecting groove 193 are maintained, and the stable reliability of the movement of the piston 3 toward the second control chamber 24 is ensured.

As shown in fig. 1, when the piston 3 moves to the end position of the second control chamber 24, the first annular groove 31 connects the third oil passage 13 and the fifth oil passage 15, so that the oil in the first control chamber 51 flows to the oil outlet pipe through the third oil passage 13, the first annular groove 31, the fifth oil passage 15 and the port T1 in sequence, so that the piston cylinder 2 moves relative to the housing 1 in the direction of the first control chamber 51 under the action of the pressure difference between the oil on both sides of the first control chamber 51 and the second control chamber 52, the port P is switched to be connected with the second oil hole 22, the first oil hole 21 is switched to be connected with the port T1, and the reversing operation of the piston 3 is realized.

When the piston 3 moves towards the first control chamber 23, high-pressure oil in the oil inlet pipe flows to the second control chamber 24 sequentially through the port P, the first connecting groove 191 and the second oil hole 22, and simultaneously oil in the first control chamber 23 flows to the oil outlet pipe sequentially through the first oil hole 21, the second connecting groove 192 and the port T1, so that the piston 3 moves towards the first control chamber 23 under the action of the pressure difference between the oil on two sides of the first control chamber 23 and the second control chamber 24, the second working chamber 19 sucks liquid through the second liquid inlet hole 17, and the liquid in the first working chamber 10 is discharged through the first liquid outlet hole 16 by the first plunger 41 in the first working chamber 10.

In the above process, the first control chamber 51 is communicated with the oil outlet pipe sequentially through the third oil passage 13, the fourth oil passage 14, the first control chamber 23, the first oil hole 11 and the T1, so that the piston cylinder 2 is fixed at the terminal position of the first control chamber 51 under the action of the pressure difference between the oil on both sides of the first control chamber 51 and the second control chamber 52, the stable communication state of the first connecting groove 191 and the second oil hole 22 and the stable communication state of the first oil hole 21 and the second connecting groove 192 are maintained, and the stable and reliable movement of the piston 3 towards the first control chamber 23 is ensured.

When the piston 3 moves to the terminal position of the first control chamber 23, as shown in fig. 2, the first annular groove 31 connects the first oil passage 11 and the third oil passage 13, so that the high-pressure oil in the oil inlet pipe flows to the first control chamber 51 through the port P, the first oil passage 11, the first annular groove 31 and the third oil passage 13 in sequence, the pressure in the first control chamber 51 and the pressure in the second control chamber 52 are both equal to the pressure in the port P, so that the piston cylinder 2 moves relative to the housing 1 in the direction of the second control chamber 52 under the action of the area difference between the first control chamber 51 and the second control chamber 52, the port P is cut back to be communicated with the first oil hole 21, the second oil hole 22 is cut back to be communicated with the port T2, and the piston 3 is switched again.

And the continuous compression work and output of the reciprocating plunger pump to the liquid are completed through the circulation operation. The reciprocating plunger pump of the present embodiment can deliver, for example, water, oil, mud, and other fluids such as air.

Claims

1. A reciprocating plunger pump is characterized by comprising a shell, a piston cylinder, a piston and a first plunger; a first working chamber for outputting fluid is arranged in the shell, a P port, a T1 port, a T2 port, a first liquid inlet hole and a first liquid outlet hole are formed in the shell, the P port is connected with an oil inlet pipe, and a T1 port and a T2 port are connected with an oil outlet pipe;

when the piston moves to an axial terminal position relative to the piston cylinder, the piston cylinder moves axially relative to the shell, and the communication relation switching of the first oil hole and the second oil hole with the P port, the T1 port and the T2 port is completed;

a first oil way, a second oil way, a third oil way, a fourth oil way and a fifth oil way are arranged on the shell; a first annular groove is formed in the first plunger; one end of the first oil way is communicated with the port P, and the other end of the first oil way is selectively communicated with the first annular groove; the second oil way is used for communicating the port P with the second control cavity; one end of the third oil way is communicated with the first control cavity, and the other end of the third oil way is communicated with the first annular groove; one end of the fourth oil way is communicated with the third oil way, and the other end of the fourth oil way is communicated with the first control chamber; one end of the fifth oil way is communicated with a T1 port, and the other end of the fifth oil way is selectively communicated with the first annular groove; when the piston moves to the terminal position of the first control chamber, the first oil path is communicated with the first annular groove; when the piston moves to the terminal position of the second control chamber, the fifth oil path is communicated with the first annular groove; a damping hole is formed in the fourth oil way;

the piston is in a step structure form, and steps on two sides are respectively part of the first control chamber and the second control chamber.

2. The reciprocating plunger pump of claim 1, wherein the housing is provided with a first connecting groove; the first connecting groove is located between the shell and the piston cylinder, is an annular groove distributed along the axial direction, and is communicated with the port P.

3. The reciprocating plunger pump of claim 1, wherein the housing is provided with a second connecting slot; the second connecting groove is located between the shell and the piston cylinder, is an annular groove arranged along the axial direction, and is communicated with a T1 port and an oil return cavity.

4. The reciprocating plunger pump of claim 1, wherein the housing has a third connecting slot; the third connecting groove is an annular groove arranged along the axial direction and is communicated with a port T2.

5. The reciprocating plunger pump of claim 1, characterized in that the housing is of a split structure, and has a left end cover and a right end cover which are detachable from each other at two ends, the left end cover is provided with a left convex column extending into the piston cylinder, and the right end cover is provided with a right convex column extending into the piston cylinder; a first control chamber is formed between the left convex column and the piston in the piston cylinder, and a second control chamber is formed between the right convex column and the piston in the piston cylinder.

6. The reciprocating plunger pump of claim 5, wherein the piston cylinder comprises an expanding section and a main body section from left to right, the diameter of the expanding section is larger than that of the main body section, a first control cavity is formed between the expanding section and the left end cover, a return oil cavity is formed between the right end face of the expanding section and the shell, and a second control cavity is formed between the right end face of the main body section and the right end cover.

7. The reciprocating plunger pump of claim 1, further comprising a second plunger, wherein a second working chamber, a second fluid inlet, and a second fluid outlet are disposed within the housing, and wherein the second plunger is disposed within the second working chamber and fixedly attached to the piston.