Pump head mechanism of slurry pump

Abstract

The pump head mechanism comprises a cylinder body, a piston and a driving rod for driving the piston to reciprocate in the cylinder body are arranged in the cylinder body, the piston is sleeved with a rubber sealing sleeve which is in dynamic sealing with the inner wall of the cylinder body, and an annular groove parallel to the rubber sealing sleeve is formed in the side wall of the piston. An expandable sealing bag piece is arranged in the annular groove, an air injection channel communicated with the annular groove is formed in the side, close to the driving rod, of the piston, and an air injection part is further arranged on the cylinder body and penetrates through the air injection channel to inflate the sealing bag piece. According to the pump head mechanism of the slurry pump, when the rubber sealing sleeve on the piston is abraded due to long-time work, the sealing bag piece is inflated through the air injection part, so that the sealing bag piece is expanded to abut against the inner wall of the cylinder body, the sealing bag piece blocks a gap between the piston and the inner wall of the cylinder body, and slurry is prevented from leaking from the gap between the cylinder body and the piston; the output quantity of the slurry pump is insufficient, and the working efficiency is influenced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mud pumps, in particular to a mud pump head mechanism. BACKGROUND

[0002] A mud pump is a machine used to deliver mud or water to a borehole during drilling. Commonly used mud pumps are mainly divided into piston type mud pumps and plunger type mud pumps. When working, the mud pump is driven by a power machine to rotate the crankshaft of the pump. The crankshaft drives the piston or plunger to move reciprocally in the pump cylinder. Under the alternating action of the suction and discharge valves, the purpose of pressure delivery and circulation of the flushing liquid is achieved.

[0003] For example, a patent with publication number CN117605640B and publication date August 2, 2024 discloses a drainage type wear-reducing mud pump. The pump includes a cylinder and a piston that is driven by a piston rod to reciprocate within the cylinder. The piston includes a piston core, a rigid support plate, a drainage end head, and a protective ring. The piston core is fixedly connected to the piston rod at one end face. The drainage end head is installed on the other end face of the piston core. The rigid support plate is located between the piston core and the drainage end head. The protective ring is also located between the piston core and the drainage end head and is sleeved on the outer peripheral part of the rigid support plate. By improving the structure of the piston, especially by installing a drainage end head on the pressure-bearing end face of the piston, the pressure accumulation in the corner adjacent to the inner wall surface of the cylinder is avoided, the sand particles that penetrate between the peripheral side of the piston and the inner wall surface of the cylinder are significantly reduced, the wear is slowed down, and the service life of the mud pump is extended.

[0004] The mud contains a large amount of solid particles (such as sand, rock debris, etc.). When these particles enter the inside of the cylinder, they will cause erosion and wear to the piston face and the sealing element. In addition, the high viscosity of the mud also increases the flow resistance of the fluid. When the piston is moving, the sealing element will bear a greater frictional force, accelerating the wear rate of the sealing element on the piston. When the sealing element is worn, a gap is formed between the sealing element and the cylinder, and mud can easily leak from the gap between the cylinder liner and the sealing element, which can cause insufficient output flow of the mud pump and affect work efficiency. SUMMARY

[0005] The present application aims to provide a mud pump head mechanism to solve the above-mentioned deficiencies in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] The mud pump head mechanism comprises a cylinder, a piston arranged in the cylinder, a driving rod for driving the piston to reciprocate in the cylinder, a rubber sealing sleeve arranged on the piston, a ring groove arranged on the side wall of the piston, an inflatable sealing bag arranged in the ring groove, an air injection channel arranged on the side of the piston close to the driving rod and connected with the ring groove, and an air injection part arranged on the cylinder and penetrating the air injection channel to inflate the sealing bag.

[0008] The ring groove comprises an outer groove section and an inner groove section connected with each other, the inner groove section has a rectangular cross section, and the outer groove section has a trumpet-shaped cross section.

[0009] The outer groove section is divided into a narrow end and a wide end, the narrow end of the outer groove section is connected with the inner groove section, and the width of the inner groove section is consistent with the width of the wide end of the outer groove section.

[0010] The air injection part comprises an air injection pump mounted on the outside of the cylinder, an air injection pipeline connected with the air injection pump, and the other end of the air injection pipeline penetrates the air injection channel and is connected with the sealing bag.

[0011] The one end of the air injection pipeline arranged in the cylinder is provided with a plurality of shunt branch pipes for shunting high-pressure gas from the air injection pump.

[0012] The ring groove arranged on the side wall of the piston is provided with two ring grooves arranged coaxially, a blowing bag is arranged in the ring groove away from the rubber sealing sleeve, and the blowing bag is connected with one shunt branch pipe of the air injection pipeline.

[0013] The blowing bag is provided with a plurality of blowing holes uniformly arranged in the circumferential direction on the side close to the sealing bag.

[0014] The piston is further provided with a pulling part connected with the rubber sealing sleeve, one shunt branch pipe of the air injection pipeline is connected with the pulling part, the pulling part is inflated by the air injection pump, and the rubber sealing sleeve is pulled by the pulling part.

[0015] The rubber sealing sleeve has a circular cap shape and is arranged on the end of the piston away from the driving rod, and the rubber sealing sleeve is divided into an annular part arranged on the side wall of the piston and a sheet part attached to the surface of the piston.

[0016] The pulling part comprises a lightening groove formed in the piston, a plurality of connecting grooves are formed in the side of the piston close to the rubber sealing sleeve and communicated with the lightening groove, the connecting grooves are arranged along the circumference of the piston, a sliding plate is slidably arranged in the lightening groove, the sliding plate is connected with the groove bottom of the lightening groove through a return spring, a plurality of connecting rods are connected with the sliding plate, and the connecting rods correspond to the connecting grooves one by one.

[0017] The beneficial effects of the present application are as follows: in the above technical solution, the mud pump head mechanism provided by the present application is provided with a sealing capsule, when the rubber sealing sleeve on the piston is worn due to long-time work, the sealing capsule is inflated by the air injection part, so that the sealing capsule is expanded against the inner wall of the cylinder body, the sealing capsule blocks the gap between the piston and the inner wall of the cylinder body, and the leakage of mud from the gap between the cylinder body and the piston is avoided, so that the insufficient output of the mud pump and the influence on the work efficiency are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0019] Figure 1 The structure schematic diagram of the mud pump head mechanism provided by the embodiment of the present application is shown in the figure.

[0020] Figure 2 The side view schematic diagram of the mud pump head mechanism provided by the embodiment of the present application is shown in the figure.

[0021] Figure 3 The A-A cross-sectional schematic diagram of the mud pump head mechanism provided by the embodiment of the present application is shown in the figure. Figure 2

[0022] Figure 4 The B enlarged schematic diagram of the mud pump head mechanism provided by the embodiment of the present application is shown in the figure. Figure 3

[0023] Figure 5 The state schematic diagram of the piston moving to the middle of the cylinder body provided by the embodiment of the present application is shown in the figure.

[0024] Figure 6 The cooperation schematic diagram of the piston and the sealing capsule provided by the embodiment of the present application is shown in the figure.

[0025] Figure 7 The structure schematic diagram of the piston provided by the embodiment of the present application is shown in the figure.

[0026] ​​Figure 8 Fig. 6 is a schematic view of the air blowing bag when the piston pushes the mud out of the cylinder;

[0027] Figure 9 Fig. 7 is a schematic view of the air blowing bag when the piston sucks the mud into the cylinder;

[0028] Figure 10 Fig. 8 is a schematic view of the structure of the air blowing bag;

[0029] Figure 11 Fig. 9 is a schematic view of the structure of the pulling part inside the piston;

[0030] Figure 12 Fig. 10 is a schematic view of the state of the pulling part when the pulling part pulls the rubber sealing sleeve to deform.

[0031] Explanation of reference signs:

[0032] 1, cylinder; 11, air cavity; 12, mud cavity; 2, piston; 3, driving rod; 4, rubber sealing sleeve; 5, ring groove; 51, outer groove section; 52, inner groove section; 6, sealing bag member; 7, air injection channel; 8, air injection pipeline; 9, air blowing bag; 10, air blowing hole; 13, pulling part; 131, weight-reducing groove; 132, sliding plate; 133, reset spring; 134, connecting rod; 135, connecting groove; 136, exhaust port. DETAILED DESCRIPTION

[0033] In order to make the technical personnel in the art better understand the technical solutions of the present application, the following will be combined with the accompanying drawings to make a detailed description. Figures 1-12 The present application will be further described in detail.

[0034] The embodiment of the present application provides a mud pump head mechanism, which comprises a cylinder 1, a piston 2 and a driving rod 3 for driving the piston 2 to reciprocate in the cylinder 1 are arranged in the cylinder 1, a rubber sealing sleeve 4 for dynamic sealing with the inner wall of the cylinder 1 is arranged on the piston 2, a ring groove 5 parallel to the rubber sealing sleeve 4 is arranged on the side wall of the piston 2, a sealing bag member 6 capable of swelling is arranged in the ring groove 5, a plurality of air injection channels 7 connected with the ring groove 5 are arranged on the side of the piston 2 close to the driving rod 3, an air injection part is further arranged on the cylinder 1, the air injection part fills air into the sealing bag member 6 through the air injection channels 7, and the sealing bag member 6 swells to block the gap between the piston 2 and the inner wall of the cylinder 1.

[0035] Specifically, in the embodiment, the cylinder body 1 is in the shape of a cylindrical tube as a whole, the piston 2 is in the shape of a cylinder that is adapted to the inner wall of the cylinder body 1, the piston 2 is slidingly installed inside the cylinder body 1, a rubber sealing sleeve 4 is sleeved on the piston 2, the rubber sealing sleeve 4 is sleeved on the end of the piston 2 that is away from the driving rod 3, due to the presence of the rubber sealing sleeve 4, the piston 2 is in close contact with the inner wall of the cylinder body 1 without any gap, at this time, due to the presence of the piston 2, the space inside the cylinder body 1 is divided into two parts, i.e., a gas cavity 11 and a mud cavity 12, one end of the driving rod 3 is fixedly connected with the end of the piston 2, the other end of the driving rod 3 extends out of the gas cavity 11 of the cylinder body 1 and is connected with a power unit, the power unit can be selected from an electric motor, a crankshaft, a connecting rod and a cross head, the electric motor drives the crankshaft to rotate, the crankshaft drives the cross head to move through the connecting rod, and the cross head drives the piston 2 to make reciprocating motion inside the cylinder body 1 through the driving rod 3 (this is the prior art, and the principle will not be described in detail), the cylinder body 1 is further provided with a suction valve and a discharge valve, the suction valve and the discharge valve are located on one side of the mud cavity 12 of the cylinder body 1, and the suction valve and the discharge valve can be opened and closed through remote control, which is the prior art, and the principle will not be described in detail, when the mud pump is working, the driving rod 3 drives the piston 2 to move inside the cylinder body 1 under the action of the power unit, at this time, the volume of the gas cavity 11 inside the cylinder body 1 decreases, the volume of the mud cavity 12 increases, the pressure in the mud cavity 12 decreases to form a negative pressure, at this time, the suction valve is opened under the action of the atmospheric pressure, the mud enters the mud cavity 12 of the cylinder body 1, and the suction process of the mud is completed, then, the driving rod 3 drives the piston 2 to move in the opposite direction, so that the volume of the mud cavity 12 inside the cylinder body 1 increases, and the pressure increases, at this time, the suction valve is closed, the discharge valve is opened, the mud in the mud cavity 12 is pushed by the piston 2, the mud is sprayed out of the discharge valve, and the discharge process of the mud is completed.

[0036] The prior art has the following disadvantages: the existing mud contains a large amount of solid particles (such as sand, rock debris, etc.), when the particles enter the mud cavity 12 of the cylinder body 1, the particles will cause erosion and wear of the piston 2 and the rubber sealing sleeve 4, and the high viscosity of the mud will increase the flow resistance of the fluid, when the piston 2 moves, the rubber sealing sleeve 4 will bear greater friction, which will accelerate the wear efficiency of the rubber sealing sleeve 4 on the piston 2, when the rubber sealing sleeve 4 is worn, a gap will be formed between the rubber sealing sleeve 4 and the cylinder body 1, the mud in the mud cavity 12 is easy to leak into the gas cavity 11 through the gap between the cylinder body 1 and the rubber sealing sleeve 4, which will easily cause insufficient output flow of the mud pump and affect the working efficiency.

[0037] In order to solve the above problems, in the embodiment, a ring groove 5 is arranged on the side wall of the piston 2 in parallel with the rubber sealing sleeve 4, the ring groove 5 is coaxially arranged between the piston 2 and the rubber sealing sleeve 4, the position of the ring groove 5 is closer to the air cavity 11 relative to the rubber sealing sleeve 4, a sealing capsule 6 capable of being inflated and expanded is arranged in the ring groove 5, the sealing capsule 6 is also in a whole annular shape, the sealing capsule 6 is coaxially arranged between the ring groove 5, the sealing capsule 6 is made of optional silicone rubber, ethylene-propylene-diene rubber, nitrile rubber, fluororubber and natural rubber as a main material, the specific material selection of the sealing capsule 6 is determined according to the environment in which the sealing capsule 6 is located, in the embodiment, because the sealing capsule 6 mainly contacts the mud, the main material of the sealing capsule 6 can be selected as natural rubber, and the air injection part can be selected as a combination of an air injection pump (not shown in the figure) and an air injection pipeline 8, one end of the air injection pump is connected with the air injection pipeline 8, the other end of the air injection pipeline 8 penetrates through an air injection channel 7 on the piston 2 and is connected with the sealing capsule 6 in the ring groove 5, and the cylinder body 1 should also be provided with a sensor (not shown in the figure) for monitoring the leakage of the mud, the sensor is in communication connection with the air injection pump, when the sensor detects the leakage, the sensor sends a working signal to the air injection pump, the air injection pump works to inject air into the inside of the sealing capsule 6 through the air injection pipeline, the sealing capsule 6 is inflated and expanded, the surface of the expanded sealing capsule 6 abuts against the inner wall of the cylinder body 1, blocks the gap between the piston 2 and the inner wall of the cylinder body 1, realizes the sealing between the air cavity 11 and the mud cavity 12, avoids the leakage of the mud from the gap between the cylinder body 1 and the piston 2, and causes the insufficient output of the mud pump and the influence on the working efficiency.

[0038] In the embodiment, the air injection pipeline 8 occupies a certain space in the air cavity 11, so that the air cavity 11 still has a certain space at the end of each stroke of the piston 2 to accommodate the air injection pipeline 8, preferably, the air injection pipeline 8 can be arranged in a spiral shape, so that it is more convenient to adapt to the reciprocating motion of the piston 2 through the extension and contraction.

[0039] When the expanded sealing capsule 6 moves together with the piston 2 in the inside of the cylinder body 1, the inner wall of the cylinder body 1 will apply a friction force to the sealing capsule 6, the direction of the friction force is opposite to the direction of the movement of the sealing capsule 6, under the action of the friction force, the sealing capsule 6 is easy to be separated from the ring groove 5, which affects the sealing effect between the air cavity 11 and the mud cavity 12.

[0040] Preferably, the ring groove 5 includes an outer groove segment 51 and an inner groove segment 52 connected in communication, the cross section of the inner groove segment 52 is in a rectangular shape, the cross section of the outer groove segment 51 is in a horn shape, and the sealing capsule 6 is arranged in the inner groove segment 52.

[0041] Specifically, in the embodiment, the outer groove section 51 has a cross-section in the shape of a trumpet, so that the outer groove section 51 can be divided into a narrow end and a wide end. According to the cross-section of the outer groove section 51, the narrow end refers to the end with a smaller diameter of the outer groove section 51, and the wide end refers to the end with a larger diameter of the outer groove section 51. The narrow end of the outer groove section 51 is in communication with the inner groove section 52, and the edge of the inner groove section 52 is away from the connection position of the outer groove section 51 and the inner groove section 52 by a distance. When the sealing bag 6 is inflated, the sealing bag 6 is first filled with the inner groove section 52, and then the sealing bag 6 continues to expand to extend out of the outer groove section 51 and abut against the inner wall of the cylinder 1. At this time, the entire ring groove 5 corresponds to a clamp to clamp the sealing bag 6. When the sealing bag 6 moves together with the piston 2 inside the cylinder 1, the sealing bag 6 clamped by the ring groove 5 can avoid the interference of the friction force from the inner wall of the cylinder 1, and the situation that the sealing bag 6 is separated from the ring groove 5 can be avoided.

[0042] It should be noted that when the rubber sealing sleeve 4 on the piston 2 is damaged due to friction, the presence of the sealing bag 6 prevents the mud originally in the mud cavity 12 from entering the air cavity 11. At this time, the mud is blocked by the sealing bag 6. The mud pump delivers mud, which is mainly composed of water and soil, and some hard particulate matter such as stones may exist in the mud. The hard particulate matter in the mud is easy to be stuck in the gap of the damaged rubber sealing sleeve 4. When the piston 2 reciprocates with the rubber sealing sleeve 4 and the sealing bag 6 in the cylinder 1, the hard particulate matter blocked by the sealing bag 6 will continuously rub against the sealing bag 6 and the inner wall of the cylinder 1, which may even pierce the sealing bag 6 and affect the sealing effect of the sealing bag 6.

[0043] To solve the above problems, in the embodiment, two ring grooves 5 are arranged on the side wall of the piston 2, and the two ring grooves 5 are coaxially arranged. A blowing bag 9 is arranged in the ring groove 5 away from the rubber sealing sleeve 4. The blowing bag 9 is annular, and a plurality of blowing holes 10 are uniformly arranged on the side of the blowing bag 9 close to the sealing bag 6 in the circumferential direction. A plurality of shunt branches (in the embodiment, the number of the shunt branches is two, and the shunt branches are not shown in the figure) are arranged on the gas injection pipeline 8. The two shunt branches are respectively in communication with the sealing bag 6 and the blowing bag 9. An electric control valve (not shown in the figure) is arranged between the shunt branches and the sealing bag 6 and the blowing bag 9.

[0044] Specifically, in the embodiment, the pressure of the high-pressure gas injected by the gas injection pump is greater than the pressure of the mud in the mud chamber 12 entering the cylinder 1. It should be noted that when the piston 2 moves in the cylinder 1 to suck and push the mud, the pushing stroke of the piston 2 is more likely to cause the stones in the mud to enter the gap on the rubber sealing sleeve 4. In the pushing stroke of the piston 2, the piston 2 compresses the space of the mud chamber 12, and the mud in the mud chamber 12 is discharged from the discharge valve. At this time, the pressure in the mud chamber 12 increases, and the hard particles in the mud are more likely to be pushed into the gap on the rubber sealing sleeve 4 under the action of high pressure. In the suction stroke of the piston 2, the piston 2 compresses the gas chamber 11, so that a negative pressure is formed in the mud chamber 12. Under the action of the negative pressure, the mud is sucked into the mud chamber 12. However, due to the low pressure, the hard particles in the mud have relatively small power to enter the gap on the rubber sealing sleeve 4. Compared with the pushing stroke of the piston 2, the hard particles in the mud are less likely to enter the gap on the rubber sealing sleeve 4 in the suction stroke of the piston 2.

[0045] When the rubber sealing sleeve 4 leaks due to wear during the suction process of the piston 2, the electric control valve corresponding to the sealing capsule 6 is opened, and the gas injection pump starts to work. The gas injection pump injects gas into the inside of the sealing capsule 6 through the gas injection pipeline. The sealing capsule 6 is inflated and expanded. The surface of the expanded sealing capsule 6 abuts against the inner wall of the cylinder 1, isolates the gap between the piston 2 and the inner wall of the cylinder 1, realizes the sealing between the gas chamber 11 and the mud chamber 12, and avoids the leakage of mud from the gap between the cylinder 1 and the rubber sealing sleeve 4.

[0046] When the suction stroke of the piston 2 is completed, and the push stroke is needed to discharge the mud in the mud cavity 12 from the discharge valve, the air injection pump works reversely to extract the gas in the sealing bag 6, and the sealing bag 6 shrinks into the corresponding annular groove 5. Slightly in advance, when the electric control valve corresponding to the sealing bag 6 is closed, and the electric control valve corresponding to the air blowing bag 9 is opened, the air injection pump continues to work, the air injection pump injects high-pressure gas into the air injection pipeline 8, the high-pressure gas makes the air blowing bag 9 expand, the expanded air blowing bag 9 abuts against the inner wall of the cylinder body 1 to isolate the gas cavity 11 from the mud cavity 12, and synchronously, there is a cavity between the expanded air blowing bag 9 and the rubber sealing sleeve 4 (the cavity is the space where the sealing bag 6 expands originally), with the continuous injection of high-pressure gas by the air injection pump, the high-pressure gas is blown out from the air blowing hole 10 on the air blowing bag 9, because the air blowing hole 10 is arranged on the side of the air blowing bag 9 close to the rubber sealing sleeve 4, and the pressure of the high-pressure gas is greater than the pressure of the mud in the mud cavity 12, therefore, after the high-pressure gas blown out from the air blowing hole 10 fills the entire cavity, the high-pressure gas will rush into the mud cavity 12 from the gap in the rubber sealing sleeve 4, when the high-pressure gas is rushed out from the gap in the rubber sealing sleeve 4, the hard particle materials stuck in the gap of the rubber sealing sleeve 4 can be pushed into the mud cavity 12, then, with the continuous work of the air injection pump, the high-pressure gas continues to rush out from the gap of the rubber sealing sleeve 4, so that a high-pressure gas flow barrier is formed at the gap of the rubber sealing sleeve 4, realizing the gas film sealing, preventing the mud and the hard particle materials in the mud from entering the gap of the rubber sealing sleeve 4, with the piston 2 pushing the mud out of the mud cavity 12, the hard particle materials can be avoided from existing in the gap of the rubber sealing sleeve 4, so that the hard particle materials rubbing against the inner wall of the sealing bag 6 and the cylinder body 1 is avoided, and the situation that the sealing effect of the piston 2 is affected is avoided.

[0047] Finally, when the piston 2 completes the push stroke of the mud, the air injection pump works reversely, the air blowing bag 9 shrinks into the corresponding annular groove 5, then the electric control valve corresponding to the air blowing bag 9 is closed, but the electric control valve corresponding to the sealing bag 6 is opened, the air injection pump works to inject air into the sealing bag 6 through the air injection pipeline, the sealing bag 6 inflates and expands, the surface of the expanded sealing bag 6 abuts against the inner wall of the cylinder body 1 to isolate the gap between the piston 2 and the inner wall of the cylinder body 1, and the suction work of the mud continues.

[0048] It should be noted that the hard particles are easy to be stuck in the gap of the rubber seal sleeve 4 due to the shape, at this time, the high pressure airflow blown by the blowing bag 9 may also be unable to push the hard particles in the gap of the rubber seal sleeve 4 out, at this time, as the piston 2 reciprocates in the cylinder 1, the particles stuck in the rubber seal sleeve 4 continuously rub against the inner wall of the cylinder 1, which is easy to cause the sealing performance of the mud pump to decrease and the service life of the cylinder 1 to decrease.

[0049] In order to solve the above problems, preferably, the piston 2 is further provided with a pulling part 13, the pulling part 13 is connected with the rubber seal sleeve 4, one branch pipe of the gas injection pipeline 8 is connected with the pulling part 13 in communication, the pulling part 13 pulls the rubber seal sleeve 4 based on the gas injection pump inflating the inside of the pulling part 13, the edge area of the rubber seal sleeve 4 is deformed to tilt towards the central axis of the piston 2, the pulling part 13 includes a lightening groove 131 opened in the center of the piston 2, a plurality of connecting grooves 135 in communication with the lightening groove 131 are opened on the side surface of the piston 2 close to the rubber seal sleeve 4, the plurality of connecting grooves 135 are arranged along the circumference of the piston 2, a sliding plate 132 is slidingly installed in the lightening groove 131 (optionally, a rubber plate can also be used as the sliding plate 132, the edge of the rubber plate is directly fixed to the groove wall of the lightening groove 131, and the center part can be extruded to deform under pressure), the sliding plate 132 is connected with the groove bottom of the lightening groove 131 through a return spring 133, a plurality of elastic connecting rods 134 capable of deforming are connected to the sliding plate 132, the plurality of connecting rods 134 correspond to the plurality of connecting grooves 135 one by one, and the connecting rod 134 is connected with the rubber seal sleeve 4 through the corresponding connecting groove 135.

[0050] Specifically, in the present embodiment, the rubber sealing sleeve 4 is in the shape of a circular cover and is sleeved on the end of the piston 2 close to the mud cavity 12. The rubber sealing sleeve 4 is divided into an annular portion sleeved on the side wall of the piston 2 and an end side portion attached to the surface of the piston 2. The central region of the sheet-shaped portion of the rubber sealing sleeve 4 is fixedly connected, such as sulfur connected, to the surface of the piston 2, and a plurality of connecting rods 134 are connected to the edge region of the sheet-shaped portion of the rubber sealing sleeve 4. One of the branch pipes of the gas injection pipeline 8 is connected to the weight reduction groove 131. The connection position of the branch pipe and the weight reduction groove 131 is located between the rubber sealing sleeve 4 and the sliding plate 132. Obviously, in order to control the timing of gas injection, an electric control valve is arranged at the connection position of the weight reduction groove 131 and the branch pipe. It should be noted that the more the number of the connecting grooves 135 and the connecting rods 134 corresponding to the connecting grooves 135, the better. With the increase of the pulling points of the rubber sealing sleeve 4, the rubber sealing sleeve 4 is more likely to deform.

[0051] When the suction stroke of the piston 2 is completed, and the push stroke is needed to discharge the slurry in the slurry cavity 12 from the discharge valve, the air injection pump works reversely to extract the gas in the sealing bag 6, the sealing bag 6 shrinks into the corresponding annular groove 5, then, the electric control valve corresponding to the sealing bag 6 is closed, but the electric control valve corresponding to the air injection bag 9 and the pulling part 13 is opened, the movement mode of the high-pressure gas in the air injection bag 9 is consistent with the above, which will not be repeated here, the air injection pump continues to start working, the air injection pump injects high-pressure gas into the air injection pipeline 8, the high-pressure gas enters the weight-reducing groove 131 through the diversion branch, so that the high-pressure gas entering the weight-reducing groove 131 pushes the sliding plate 132 to move along the weight-reducing groove 131 towards the air cavity 11, at this time, the return spring 133 connected to the sliding plate 132 is compressed to accumulate elastic potential energy, the sliding plate 132 moves synchronously with the plurality of connecting rods 134, the plurality of connecting rods 134 pull the edge area of the sheet-shaped part of the rubber sealing sleeve 4 into the connecting groove 135 and deform towards the air cavity 11, because the rubber sealing sleeve 4 has a certain elasticity, as the plurality of connecting rods 134 are pulled, the annular part of the rubber sealing sleeve 4 sleeved on the side wall of the piston 2 will try to deform and move along the direction of the force towards the axis direction of the piston 2, when the annular part of the rubber sealing sleeve 4 deforms, the area of the annular part of the rubber sealing sleeve 4 in contact with the inner wall of the cylinder body 1 will decrease, when hard particulate matter is easy to be stuck in the notch of the rubber sealing sleeve 4, as the area of the annular part of the rubber sealing sleeve 4 in contact with the inner wall of the cylinder body 1 decreases, it is equivalent to reducing the extrusion on the hard particulate matter, so that the hard particulate matter can easily separate from the rubber sealing sleeve 4, avoiding the hard particulate matter from being stuck;

[0052] When the piston 2 completes the mud pushing stroke, the air injection pump works reversely, the air injection bag 9 shrinks into the corresponding annular groove 5, at the same time, the surface of the sliding plate 132 loses the impact from the high-pressure gas, the reset spring 133 releases the accumulated elastic potential energy, the reset spring 133 pushes the sliding plate 132 to move along the lightening groove 131 towards the direction of the mud cavity 12, the sliding plate 132 drives the plurality of connecting rods 134 to move synchronously, the plurality of connecting rods 134 push the rubber sealing sleeve 4 originally sunk into the connecting groove 135 away, the deformed rubber sealing sleeve 4 restores the sealing between the rubber sealing sleeve 4 and the inner wall of the cylinder body 1, then the electric control valve corresponding to the air injection bag 9 and the pulling part 13 is closed, but the electric control valve corresponding to the sealing bag part 6 is opened, the air injection pump works to inject air into the inside of the sealing bag part 6 through the air injection pipeline, the sealing bag part 6 inflates and expands, the surface of the expanded sealing bag part 6 abuts against the inner wall of the cylinder body 1, and the gap between the piston 2 and the inner wall of the cylinder body 1 is isolated, and the mud suction work continues.

[0053] Obviously, when the high-pressure gas pushes the sliding plate 132 to move along the lightening groove 131 towards the direction of the air cavity 11, the air between the sliding plate 132 and the lightening groove 131 is compressed with the movement of the sliding plate 132, and the resistance that the sliding plate 132 receives increases with the increase of the moving distance of the sliding plate 132, therefore, an exhaust port 136 can be arranged at the bottom of the lightening groove 131, the exhaust port 136 is connected with the air cavity 11 of the cylinder body 1, and when the distance between the sliding plate 132 and the lightening groove 131 decreases, the gas between the sliding plate 132 and the lightening groove 131 enters into the air cavity 11 of the cylinder body 1 through the exhaust port 136, so that the sliding plate 132 can move smoothly in the lightening groove 131.

[0054] The above only describes certain exemplary embodiments of the present application by way of illustration, and it is self-evident that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present application. Therefore, the above drawings and descriptions are illustrative in nature, and should not be construed as limiting the scope of protection of the claims of the present application.

Claims

1. A slurry pump head mechanism comprising a cylinder, a piston arranged in the cylinder, a driving rod for driving the piston to reciprocate in the cylinder, and a rubber sealing sleeve arranged on the piston and sealingly arranged with the inner wall of the cylinder, characterized in that, The side wall of the piston is provided with an annular groove parallel to the rubber sealing sleeve, and an inflatable sealing bag is arranged in the annular groove. An air injection channel is arranged on the side of the piston close to the driving rod and is communicated with the annular groove. An air injection part is further arranged on the cylinder body, and the air injection part injects air into the sealing bag through the air injection channel. The sealing bag is inflated to block the gap between the piston and the inner wall of the cylinder body.

2. A slurry pump head mechanism according to claim 1 wherein, The annular groove comprises an outer groove section and an inner groove section which are communicated with each other. The inner groove section has a rectangular cross section, and the outer groove section has a trumpet-shaped cross section. The sealing bag is arranged in the inner groove section, and the inner groove section is used to clamp the sealing bag.

3. A slurry pump head mechanism according to claim 2, wherein, The outer groove section is divided into a narrow end and a wide end. The narrow end of the outer groove section is communicated with the inner groove section, and the width of the inner groove section is consistent with the width of the wide end of the outer groove section.

4. A slurry pump head mechanism according to claim 1 wherein, The air injection part comprises an air injection pump mounted on the outside of the cylinder body. The air injection pump is connected with an air injection pipeline. The other end of the air injection pipeline is communicated with the sealing bag through the air injection channel.

5. A slurry pump head mechanism as claimed in claim 4, wherein, A plurality of shunt branch pipes are arranged on the end of the air injection pipeline in the cylinder body. The shunt branch pipes are used to shunt high-pressure gas from the air injection pump.

6. A slurry pump head mechanism as claimed in claim 5, wherein, Two annular grooves are arranged on the side wall of the piston. The two annular grooves are coaxially arranged. A blowing bag is arranged in the annular groove away from the rubber sealing sleeve. The blowing bag is connected with one shunt branch pipe of the air injection pipeline.

7. A slurry pump head mechanism as claimed in claim 6, wherein, A plurality of blowing holes are uniformly arranged on the side of the blowing bag close to the sealing bag in the circumferential direction.

8. A slurry pump head mechanism according to claim 7, wherein, A pulling part is further arranged on the piston. The pulling part is connected with the rubber sealing sleeve. One shunt branch pipe of the air injection pipeline is communicated with the pulling part. The pulling part pulls the rubber sealing sleeve based on the air injection pump injecting air into the pulling part.

9. A slurry pump head mechanism as claimed in claim 8, wherein, The rubber sealing sleeve is in the shape of a circular cover and is sleeved on the end of the piston away from the driving rod. The rubber sealing sleeve is divided into an annular part sleeved on the side wall of the piston and a sheet-shaped part attached to the surface of the piston.

10. A slurry pump head mechanism according to claim 9, wherein, The pulling part comprises a lightening groove arranged in the piston. A plurality of connecting grooves are arranged on the side of the piston close to the rubber sealing sleeve and are communicated with the lightening groove. The connecting grooves are arranged at intervals in the circumferential direction of the piston. A sliding plate is slidably arranged in the lightening groove. The sliding plate and the groove bottom of the lightening groove are connected through a return spring. A plurality of connecting rods are connected with the sliding plate. The connecting rods correspond to the connecting grooves one by one. The connecting rods are connected with the rubber sealing sleeve through the corresponding connecting grooves.

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