Pump head and gas-oil recovery pump

Abstract

The application discloses a pump head and an oil and gas recovery pump. The pump head comprises a shell with a hollow accommodating cavity, a first air inlet and a first air outlet arranged on the shell, an air inlet channel communicated with the first air inlet and an air outlet channel communicated with the first air outlet arranged in the shell, a piston device arranged in the accommodating cavity of the shell, the piston device being provided in two, the piston device comprising a piston assembly and a cylinder body, the piston assembly being partially located in the cylinder body and being arranged to move along the axial direction of the cylinder body, a valve plate assembly comprising a valve plate, the valve plate being located on one side of the cylinder body and being in sealing connection with the end face of one end of the cylinder body, the valve plate being provided with a second air inlet and a second air outlet, a transmission mechanism arranged in the accommodating cavity of the shell, the transmission mechanism being used for driving the piston assembly to move along the axial direction of the cylinder body to the direction of approaching or moving away from the valve plate, the transmission mechanism being located between the two cylinder bodies, and the two cylinder bodies being symmetrically arranged with the rotation axis of the transmission mechanism.

Description

Technical Field

[0001] This invention relates to the technical field of oil and gas recovery, and particularly to a pump head and an oil and gas recovery pump. Background Technology

[0002] During the transfer of gasoline from the oil depot to the car's fuel tank, gasoline generates oil vapors at each storage stage. For example, when gasoline is refueled at a gas station, it fills the fuel tank, replacing the oil vapors that previously evaporated in the tank. These oil vapors are released into the environment during refueling, causing pollution, wasting resources, and posing serious safety hazards such as fire and explosion.

[0003] To mitigate the environmental pollution and energy waste caused by oil and gas, gas stations have widely adopted vapor recovery systems. These systems recover oil and gas during refueling and store it in underground storage tanks. To achieve this recovery, a vacuum pump needs to be installed in series on the vapor recovery pipeline before it enters the underground storage tank. However, the currently used single piston pumps have relatively large piston strokes, resulting in significant vibration and noise. Summary of the Invention

[0004] The purpose of this invention is to provide a pump head and an oil and gas recovery pump.

[0005] A first aspect of the present invention provides a pump head, comprising: a housing having a hollow receiving cavity, the housing having a first air inlet and a first air outlet located in the same plane; the housing having an air inlet channel communicating with the first air inlet and an air outlet channel communicating with the first air outlet, the axes of the air inlet channel and the air outlet channel being substantially parallel, the axes of the first air inlet and the first air outlet being substantially parallel, and the axes of the air inlet channel and the first air inlet being substantially perpendicular; a piston assembly disposed within the receiving cavity of the housing, the piston assembly comprising two piston assemblies; each piston assembly comprising a piston assembly and a cylinder, a portion of the piston assembly being located within the cylinder, the piston assembly being configured to move axially along the cylinder; a valve plate assembly comprising a valve plate located on one side of the cylinder, the valve plate being sealed to one end face of the cylinder, the valve plate having a second air inlet and a second air outlet; and a transmission mechanism. The transmission mechanism, disposed within the receiving cavity of the housing, includes a crankshaft assembly and a drive shaft. The rotation axes of the crankshaft assembly and the drive shaft are located on the same axis. The crankshaft assembly is located on one side of the drive shaft, and the drive shaft drives the crankshaft assembly to rotate. The piston assembly is sleeved on the crankshaft assembly so that the transmission mechanism drives the piston assembly to move along the axial direction of the cylinder towards or away from the valve plate. The transmission mechanism is located between two cylinders, and the two cylinders are symmetrically arranged about the rotation axis of the transmission mechanism. The axes of the two cylinders are the same axis and are approximately perpendicular to the rotation axis of the transmission mechanism. The rotation axis of the transmission mechanism is approximately parallel to the axis of the first air inlet. Oil and gas sequentially pass through the first air inlet and the air inlet channel, and are introduced into the cylinder through two separate paths via the second air inlet. They then enter the air outlet channel via the second air outlet and converge in the air outlet channel before entering the first air outlet.

[0006] A second aspect of the present invention provides an oil and gas recovery pump, comprising: the pump head; a coupling device, one end of which is fixedly connected to the transmission mechanism; a motor, including a connecting end cover, the connecting end cover being fixedly connected to the housing; and the output shaft of the motor being fixedly connected to the other end of the coupling device.

[0007] The above-described technical solution of the present invention has the following beneficial technical effects:

[0008] 1. In this embodiment of the invention, the vacuuming function is achieved by using two opposing piston pumps, which has the characteristics of strong vacuuming capability and can achieve a high vacuum degree, providing sufficient vacuum margin to maintain a stable gas-liquid ratio; and the two pistons share the vacuuming process, with one piston evacuating while the other piston exhausts air during the operation of the pump head. The transmission mechanism can generate two vacuuming actions for each rotation. Compared with a single piston pump, the piston stroke is relatively small, the pump head runs more smoothly, and the vibration and noise are low.

[0009] 2. In this embodiment of the invention, the first air inlet and the first air outlet are located on the same side of the housing and face the same direction, which facilitates the laying of pipelines during installation.

[0010] 3. In this embodiment of the invention, by superimposing a reinforcing plate on one side of the valve plate in the opening direction, the valve plate can be supported when it is open, and the closing elasticity of the valve plate can be increased. When the valve plate is closed, it can be pressed tightly, making the valve plate fit more closely to the valve plate and improving the sealing performance. This can effectively reduce the thickness and rigidity of the valve plate, increase its elasticity, and further reduce the vacuum consumed during the intake and exhaust processes, avoiding excessive ineffective power consumption of the oil-gas recovery pump when opening the check valve, thereby reasonably reducing the power of the matching motor.

[0011] 4. In this embodiment of the invention, several reinforcing plates are added to increase the opening pressure; or, the reinforcing plates are thinned or removed to reduce the operating power of the oil and gas recovery pump; this facilitates the debugging and use of the oil and gas recovery pump and meets the needs of more users.

[0012] 5. In this embodiment of the invention, the use of ultra-thin valve plates reduces the power consumption of the oil and gas recovery pump during operation, reduces the power of the matching motor, and reduces the weight of the whole machine.

[0013] 6. In this embodiment of the invention, when the sidewall of the piston ring is flared, the piston ring slides along the inner wall of the cylinder, and when its large end sidewall is pressed against the inner wall of the cylinder, it can exhibit a slight inward contraction deformation to reduce the frictional resistance between the piston ring and the cylinder and the resulting mutual wear. This can delay the wear of the piston ring, and the cylinder is less prone to wear and leakage, thus extending the service life of the piston assembly. It can also effectively maintain the vacuum in the cylinder and improve the return gas capacity of the oil-gas recovery pump. The piston ring has wear-resistant and self-lubricating properties, which can reduce the frictional power consumption generated during operation and extend the service life of the piston ring; the cylinder surface has a wear-resistant coating, which can extend the service life of the cylinder. Attached Figure Description

[0014] Figure 1 This is a cross-sectional structural schematic diagram of the pump head according to the first embodiment of the present invention;

[0015] Figure 2 This is a cross-sectional structural schematic diagram of the pump head according to the second embodiment of the present invention;

[0016] Figure 3 This is a cross-sectional structural schematic diagram of the housing according to the third embodiment of the present invention;

[0017] Figure 4 This is a partial structural schematic diagram of the pump head according to the fourth embodiment of the present invention;

[0018] Figure 5 This is a three-dimensional structural schematic diagram of a pump head according to a fifth embodiment of the present invention;

[0019] Figure 6 This is a three-dimensional structural diagram of the pressure cap according to the sixth embodiment of the present invention;

[0020] Figure 7 This is a schematic diagram of the valve plate assembly according to the seventh embodiment of the present invention;

[0021] Figure 8 This is a schematic diagram of the valve plate according to the eighth embodiment of the present invention;

[0022] Figure 9 This is a cross-sectional structural schematic diagram of the valve plate assembly according to the ninth embodiment of the present invention;

[0023] Figure 10 This is a three-dimensional structural schematic diagram of a one-way valve according to the tenth embodiment of the present invention;

[0024] Figure 11 This is a partial structural schematic diagram of the valve plate assembly according to the eleventh embodiment of the present invention;

[0025] Figure 12 This is a cross-sectional structural schematic diagram of the piston device according to the twelfth embodiment of the present invention;

[0026] Figure 13 A schematic diagram of the piston ring structure is shown.

[0027] Figure 14 A schematic diagram of the crankshaft structure is shown.

[0028] Figure 15 A schematic diagram of the crank's structure is shown.

[0029] Figure 16 A schematic diagram of the counterweight block is shown.

[0030] Figure 17 This is a schematic diagram of the structure of the connecting end cap according to the thirteenth embodiment of the present invention;

[0031] Figure 18This is a schematic diagram of the structure of the connecting end cap according to the fourteenth embodiment of the present invention;

[0032] Figure 19 This is a schematic diagram of the structure of the connecting end cap according to the fifteenth embodiment of the present invention;

[0033] Figure 20 This is a schematic diagram of the coupling device according to the sixteenth embodiment of the present invention;

[0034] Figure 21 This is a schematic diagram of the structure of an oil and gas recovery pump according to the seventeenth embodiment of the present invention;

[0035] Figure 22 This is a three-dimensional structural schematic diagram of an oil and gas recovery pump according to the eighteenth embodiment of the present invention;

[0036] Figure label:

[0037] 10. Housing; 11. First air inlet; 12. First air outlet; 13. Air inlet channel; 14. Air outlet channel; 15. Gland; 101. First mounting flange; 102. First groove; 103. First mounting post; 104. Second mounting post; 105. First threaded hole; 106. Second threaded hole; 107. Mounting boss; 151. First cavity; 152. Second boss; 153. Second cavity;

[0038] 20. Piston assembly; 21. Cylinder block; 22. Piston assembly; 23. First hole; 24. Second hole; 25. Protrusion; 221. Pressure plate; 223. Support body; 224. Bushing; 225. Piston ring;

[0039] 30. Valve plate assembly; 31. Valve plate; 32. Check valve; 33. Gasket; 34. Pressure relief valve; 311. Second air inlet; 312. Second air outlet; 313. First boss; 314. Transition hole; 315. Second groove; 316. Pressure relief hole; 317. First air outlet; 318. Second mounting hole; 321. Valve plate; 322. Reinforcing plate; 341. Pressure adjusting nut; 342. Spring; 343. Steel ball;

[0040] 40. Transmission mechanism; 41. Crankshaft; 42. Crank; 43. Counterweight; 44. Drive shaft; 45. First screw; 46. Second screw; 411. Positioning part; 412. Long shaft section; 413. Cutting plane; 421. Connecting part; 422. Shaft shoulder; 423. Third mounting hole; 424. Weight reduction hole; 425a. Through groove one; 425b. Through groove two; 431. Fourth mounting hole; 432. Weight adjustment hole;

[0041] 50. Connecting end cap; 51. Connecting body; 52. Motor connecting body; 53. Pump head connecting body; 54. Positioning connecting part; 55. Arc-shaped notch; 541. First lug; 542. Second lug; 543. Third hole; 544. Fourth hole;

[0042] 60. Coupling device; 61. First coupling; 62. Second coupling; 63. Rubber gasket; 611. Motor connecting sleeve; 612. First flange; 613. First support claw; 621. Pump head connecting sleeve; 622. Second flange; 623. Second support claw;

[0043] 70. Motor; 71. Housing; 72. Protrusion; 73. Output shaft. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0045] An oil and gas recovery system mainly includes a fuel nozzle, a hose, an oil and gas separator, and a vacuum recovery pump. The fuel nozzle can be equipped with oil and gas recovery functionality. The hose has two channels: one for fueling and one for oil and gas recovery. The oil and gas separator separates the fuel path from the gas path for oil and gas recovery. Both ends of the hose connect to the fuel nozzle and the oil and gas separator, respectively. Both ends of the fuel path connect to the oil and gas separator and the outlet of the underground storage tank, respectively. Both ends of the oil and gas recovery path connect to the oil and gas separator and the inlet of the underground storage tank, respectively. An oil and gas vacuum pump is installed in series on the oil and gas recovery path, thus recovering oil and gas to the underground storage tank through the system. However, the currently used single piston pump has a relatively large piston stroke, resulting in significant vibration and noise.

[0046] In view of this, a first aspect of the present invention provides a pump head, such as Figures 1-13As shown, it includes: a housing 10, a piston device 20, a valve plate assembly 30, and a transmission mechanism 40. The housing 10 has a hollow receiving cavity, and a first air inlet 11 and a first air outlet 12 are provided on the housing 10, which are located in the same plane; the housing 10 has an air inlet channel 13 communicating with the first air inlet 11 and an air outlet channel 14 communicating with the first air outlet 12, the axes of the air inlet channel 13 and the air outlet channel 14 are parallel to each other, the axes of the first air inlet 11 and the first air outlet 12 are parallel to each other, and the air inlet channel 13 and the first air outlet 14 are parallel to each other. The axes of 11 are perpendicular to each other; piston device 20 is disposed in the receiving cavity of housing 10, and two piston devices are provided; the piston device includes a piston assembly and a cylinder 21, part of the piston assembly is located in the cylinder 21, and the piston assembly is configured to move along the axial direction of the cylinder 21; valve plate assembly 30 includes a valve plate 31, the valve plate 31 is located on one side of the cylinder 21, and the valve plate 31 is sealed to one end face of the cylinder 21, and the valve plate 31 is provided with a second air inlet and a second air outlet; transmission Mechanism 40, which is disposed in the receiving cavity of housing 10, may include a transmission mechanism including a crankshaft assembly and a drive shaft, the rotation axes of the crankshaft assembly and the drive shaft being located on the same axis, the crankshaft assembly being located on one side of the drive shaft, and the drive shaft driving the crankshaft assembly to rotate; a piston assembly being sleeved on the crankshaft assembly, so that the transmission mechanism 40 drives the piston assembly to move along the axial direction of the cylinder 21 towards or away from the valve plate 31; the transmission mechanism 40 is located between two cylinders 21, and the two cylinders 21 are symmetrically arranged about the rotation axis of the transmission mechanism 40, the axes of the two cylinders 21 being the same axis and perpendicular to the rotation axis of the transmission mechanism 40; the rotation axis of the transmission mechanism 40 is parallel to the axis of the first air inlet 11; oil and gas sequentially pass through the first air inlet 11 and the air inlet channel 13, and are respectively introduced into the cylinder 21 through the second air inlet via two separate paths, and then enter the air outlet channel 14 through the second air outlet, where they converge and enter the first air outlet 12.The housing 10 has openings at both ends to facilitate the installation of the cylinder 21 from both ends of the housing 10. The housing 10 may have grooves, one end of the cylinder 21 is embedded in the groove, and the other end of the cylinder 21 can be embedded in the mounting groove of the valve plate 31. The valve plate 31 can be fixed to the housing 10. A sealing ring can be embedded in the mounting groove of the valve plate 31. The top of the cylinder 21 squeezes the sealing ring to deform it, thereby sealing the oil and gas entering the cylinder 21 and preventing leakage from the connection. By placing the piston devices on both sides of the transmission mechanism 40 and symmetrically arranging them with respect to the rotation axis of the transmission mechanism 40, the linear opposing piston structure is made more compact, and the volume of the pump head is relatively reduced. The first air inlet 11 and the first air outlet 12 are located on the same side of the housing 10 and face the same direction, which facilitates the laying of pipelines during installation. Furthermore, the axes of the first air inlet 11 and the first air outlet 12 are parallel to the rotation axis of the transmission mechanism 40, that is, the planes where the first air inlet 11 and the first air outlet 12 are located are opposite to the motor mounting surface. The air inlet channel 13 and the air outlet channel 14 can be set to extend along the longitudinal direction of the housing 10, respectively connected to the second air inlet 311 and the second air outlet 312 on the valve plate 31 at the top (or bottom) of the cylinder 21. This allows oil and gas to enter the air inlet channel 13 through the first air inlet 11 and then pass through two paths from the second air inlet 311 on the valve plate 31 into the cylinder 21, and then enter the air outlet channel 14 through the second air outlet 312. They then converge in the air outlet channel 14 and enter the first air outlet 12. The first air outlet 12 is connected to the oil and gas recovery pipeline to recover the oil and gas to the underground oil storage tank. Figure 2 The arrows shown indicate the direction of oil and gas flow; therefore, the overall structure is compact and the layout is reasonable; and the two pistons share the vacuuming process. When the transmission shaft rotates, it drives the crankshaft assembly to rotate, thereby driving the piston assembly to reciprocate; and the two opposing pistons move in the same direction, that is, during the operation of the pump head, one piston evacuates while the other piston exhausts. The transmission mechanism 40 can generate two vacuuming actions every one rotation. Compared with a single piston pump, the piston stroke is relatively small, the pump head runs more smoothly, and the vibration and noise are low.

[0047] In an exemplary embodiment, the housing 10 may be a casting, and the air intake channel 13 and the air outlet channel 14 are shared by two opposing piston devices. Therefore, the air intake channel 13 and the air outlet channel 14 may be part of the casting, and the inner diameter of the air intake channel 13 and the air outlet channel 14 may be, for example, 10 mm.

[0048] In some embodiments, the first air inlet 11 and the first air outlet 12 are located on both sides of the transmission mechanism 40, and the height of the first air inlet 11 is higher than that of the first air outlet 12; the planes on which the first air inlet 11 and the first air outlet 12 are located are opposite to the motor mounting surface. The directions of the first air inlet 11 and the first air outlet 12 are parallel to the rotation axis of the transmission mechanism 40 and face the same direction, and the heights of the first air inlet 11 and the first air outlet 12 are staggered, which facilitates the installation of oil and gas recovery pipes and the rational arrangement of pipes; in addition, when installing the pump head, the first air inlet 11 is kept higher than the first air outlet 12 to facilitate the discharge of liquid if liquid accidentally enters the pump head. The housing 10 has a protruding mounting boss 107. The end of the mounting boss 107 facing away from the housing 10 forms a motor mounting surface. The mounting boss 107 has spaced threaded holes so that the motor can be mounted on the mounting boss 107 with threaded fasteners. The mounting boss 107 can be hollow to facilitate the installation of the coupling device 60. The mounting boss 107 can also have several elongated slots. The elongated slots can not only reduce weight but also dissipate heat.

[0049] In some embodiments, the housing 10 has protruding first mounting flanges 101 at both ends, the end faces of the first mounting flanges 101 and the end faces of the housing 10 are both located on the first mounting surface, and the first mounting surface is parallel to the rotation axis of the transmission mechanism 40; the first mounting surface has first threaded holes 105, which are distributed circumferentially and at intervals along the receiving cavity of the housing 10; the valve plate 31 has a first through hole, which is adapted to the first threaded hole 105 to install the valve plate 31 on the housing 10; the valve plate 31 has a mounting groove, and one end of the cylinder 21 is embedded in the mounting groove. The end face of the first mounting flange 101 and the end face of the housing 10 are both located on the same plane. A column protruding into the receiving cavity may be provided on the inner wall of the housing 10. The column is arranged longitudinally along the housing 10 and has a first threaded hole. A mounting screw passes through the first through hole on the valve plate 31 and is screwed into the first threaded hole to mount the valve plate 31 onto the housing 10. A groove may be provided inside the housing 10. One end of the cylinder 21 is embedded in the groove, and the other end of the cylinder 21 can be embedded in the mounting groove of the valve plate 31. An embedded sealing ring can be used. The top of the cylinder 21 compresses the sealing ring, deforming it to seal the oil and gas entering the cylinder 21 and prevent leakage from the connection. Therefore, the installation of the valve plate 31 can fix the cylinder 21 and seal the oil and gas entering the cylinder 21. At the same time, the valve plate 31 is provided with a second air inlet and a second air outlet to allow the oil and gas in the cylinder 21 to enter and exit respectively, and a one-way valve 32 is fixed on the valve plate 31. This achieves multiple benefits, making the pump head structure simple and compact, and easy to maintain.

[0050] In some embodiments, the pump head further includes: a gland 15, which is connected and fixed to a first mounting flange 101; a recessed first cavity 151 is provided on one side of the gland 15, and the opposite side of the gland 15 protrudes; a valve plate 31 is located in the first cavity 151, and the first cavity 151 communicates with the air intake passage 13; a second threaded hole 106 is provided on the first mounting flange 101, and the second threaded holes 106 are distributed circumferentially and at intervals along the first mounting flange 101; a second through hole is provided on the gland 15, and the second through hole and the second threaded hole 106 are connected. The pressure cap 15 is adapted to be installed on the first mounting flange 101; the circumferential distribution dimension of the second threaded hole 106 is larger than that of the first threaded hole 105; a first groove 102 is provided on the first mounting surface, the first groove 102 surrounds the inner cavity of the housing 10, and the first groove 102 is located between the first threaded hole 105 and the second threaded hole 106; a first sealing ring is provided in the first groove 102, and the end face of the pressure cap 15 contacts the first sealing ring to prevent oil and gas in the housing 10 from escaping to the outside atmosphere. The gland 15 can be cast. The mounting screw passes through the second through hole on the gland 15 and is screwed into the second threaded hole 106 to install the gland 15 on the first mounting flange 101. At the same time, the first sealing ring is squeezed and deformed to achieve a seal at the connection to prevent oil and gas in the housing 10 from escaping to the outside atmosphere. The valve plate 31 is located in the first cavity 151, which is connected to the intake channel 13. In this way, oil and gas enter the first cavity 151 through the intake channel 13 and then enter the cylinder 21 through the second intake port.

[0051] In some embodiments, the valve plate 31 has a first boss 313 extending along the side opposite to the cylinder body 21; a second air outlet 312 penetrates the first boss 313, and the first boss 313 has a transition hole 314, the axis of the second air outlet 312 being parallel to the axis of the transition hole 314; a second groove is provided on the plane of the first boss 313 on the side opposite to the cylinder body 21, the second groove being arranged along the circumference of the first boss 313, and both the second air outlet 312 and the transition hole 314 are located in the second... Within the groove area; a second sealing ring is provided in the second groove; a second boss 152 is provided in the first cavity 151, the shape of the second boss 152 matches the first boss 313, a recessed second cavity 153 is provided in the second boss 152, the second cavity 153 is connected to the transition hole 314, and the one-way valve 32 at the second air outlet 312 is located in the second cavity 153; the second boss 152 contacts the second sealing ring to prevent the oil and gas in the first cavity 151 and the second cavity 153 from flowing between each other. When the gland 15 is installed on the first mounting flange 101, the second boss 152 squeezes the second sealing ring to achieve a seal, which can prevent the oil and gas in the first cavity 151 and the second cavity 153 from flowing between each other. The oil and gas in the cylinder 21 are pushed by the piston assembly to be discharged from the second air outlet 312 and enter the second cavity 153 to achieve pressure release, which can reduce the operating power of the motor.

[0052] In some embodiments, the outer surface of the housing 10 is provided with a plurality of spaced-apart first mounting posts 103 for mounting the pump head to fix its relative position; or, the outer surface of the gland 15 is provided with a plurality of spaced-apart second mounting posts 104 for mounting the pump head to fix its relative position. The first mounting posts 103 may have threaded holes, and the end faces of the first mounting posts 103 facing away from the housing 10 form the same mounting plane; similarly, the second mounting posts 104 may also have threaded holes, and the end faces of the second mounting posts 104 facing away from the gland 15 form the same mounting plane. This allows the pump head to be fixed on multiple planes such as the side, top, or bottom to meet the needs of various practical operating conditions. In addition, the outer surface of the gland 15 is provided with spaced-apart protrusions to increase the heat dissipation area.

[0053] In some embodiments, such as Figures 7-11As shown, the valve plate assembly 30 specifically includes a valve plate 31 and a one-way valve 32. The valve plate 31 is located on one side of the cylinder body, and the valve plate 31 is sealed to one end face of the cylinder body. The valve plate 31 is provided with a second air inlet 311 and a second air outlet 312. The second air inlet 311 is used to introduce oil and gas into the cylinder body, and the second air outlet 312 is used to discharge oil and gas from the cylinder body. The one-way valve 32 is installed on one side of the valve plate 31, and the one-way valve 32 is located downstream of the direction in which oil and gas flow through the second air inlet 311 or the second air outlet 312. The one-way valve 32 includes a valve plate 321 and a reinforcing plate 322. The valve plate 321 covers the second air inlet 311 or the second air outlet 312, and the valve plate 321 is located between the reinforcing plate 322 and the valve plate 31. Oil and gas sequentially enter the cylinder body through the second air inlet 311 and the one-way valve 32, and are discharged through the second air outlet 312 and the one-way valve 32. A groove may be provided on one end face of the cylinder block, and a sealing ring is embedded in the groove. When the valve plate 31 is fixed to the housing, the valve plate 31 presses the sealing ring, causing the sealing ring to be squeezed and deformed, thereby sealing the oil and gas entering the cylinder block and preventing the oil and gas from escaping from the connection between the valve plate 31 and the end face of the cylinder block. When the piston moves up and down in the cylinder block, the piston ring seals with the inner wall of the cylinder block. The one-way valve 32 is used to control the one-way flow of oil and gas and prevent backflow of oil and gas. For example, at the second air inlet 311 The one-way valve 32 is set as the first one-way valve, and the one-way valve 32 at the second outlet 312 is set as the second one-way valve; when the piston moves away from the valve plate 31 in the cylinder, a vacuum is drawn in the cylinder to form a negative pressure, and oil and gas enter the cylinder through the second inlet 311. At this time, the first one-way valve at the second inlet 311 opens, that is, the valve plate 321 is pushed open from the valve plate 31, and the second one-way valve at the second outlet 312 closes, that is, the valve plate 321 is attached to the valve plate 31; when the piston moves away from the valve plate 31 in the cylinder, the piston moves away from the valve plate 31, and the piston moves away from the valve plate 31 in the cylinder. When ... When the plug moves towards the valve plate 31 within the cylinder, the oil and gas in the cylinder are discharged through the second outlet 312. At this time, the second check valve at the second outlet 312 opens, meaning the valve plate 321 springs open from the valve plate 31, and the first check valve at the second inlet 311 closes, meaning the valve plate 321 adheres to the valve plate 31. By superimposing a reinforcing plate 322 on one side of the valve plate 321 in the opening direction, support can be provided for the valve plate 321 in the open state, while also increasing the closing elasticity of the valve plate 321. When the valve plate 321 is closed, it can be pressed tightly, making the valve plate 321 adhere more closely to the valve plate 31, thus improving the sealing performance. This effectively reduces the thickness and rigidity of the valve plate 321, increases its elasticity, and further reduces the vacuum consumed during intake and exhaust processes, avoiding excessive ineffective power consumption by the oil and gas recovery pump when opening the check valve 32, thereby reasonably reducing the power of the matching motor.

[0054] In some embodiments, the thickness of the reinforcing plate 322 is adjustable to regulate the closing or opening pressure of the one-way valve 32. The reinforcing plate 322 comprises several pieces, and increasing or decreasing the number of reinforcing plates 322 adjusts the closing or opening pressure of the one-way valve 32. The thickness of each reinforcing plate 322 can be different, for example, it may include 0.05mm, 0.08mm, 0.1mm, and 0.15mm; the thickness of each reinforcing plate 322 can also be the same, for example, 0.1mm. In practical applications, the reinforcing plate 322 can be adjusted according to the closing or opening pressure requirements of the one-way valve 32 of the oil and gas recovery pump. For example, several reinforcing plates 322 can be added to increase the opening pressure; or the reinforcing plates 322 can be thinned or removed to reduce the operating power of the oil and gas recovery pump. This facilitates the commissioning and use of the oil and gas recovery pump and meets the needs of more users.

[0055] In some embodiments, the valve plate 321 is configured as a thin rectangular structure; the ratio of the length to the width of the valve plate 321 ranges from 2.5 to 1. Specifically, the side corresponding to the length direction of the valve plate 321 is the long side, and the side corresponding to the width direction of the valve plate 321 is the short side, and the maximum size ratio of the long side to the short side can be set to 5:2.

[0056] In some embodiments, the thickness of the valve plate 321 is set to 0.03mm-0.1mm. The valve plate 321 primarily serves a sealing function and can be made of thin steel sheet of 7Cr27Mo2 material, or thin steel sheet of 2Cr13, 0Cr17Ni4Cu4Nb, 0Cr15Ni7Mo2Al, or PEEK material. The hardness range of the valve plate 321 can be set to HRC47-52, with a preferred hardness of HRC50. The surface roughness of the valve plate 321 is required to be lower than Ra0.05 or Ra0.1. Preferably, the thickness of the valve plate 321 is 0.05mm or 0.08mm. A thinner valve plate 321 can improve the sealing performance of the air inlet and outlet, while reducing intake and exhaust power consumption.

[0057] In some embodiments, the thickness of the reinforcing sheet 322 is set to 0.1mm-0.3mm. The material of the reinforcing sheet 322 may specifically include PTFE or 304 stainless steel; in an exemplary embodiment, the reinforcing sheet 322 is made of PTFE, and its thickness can be selected as 0.3mm. The reinforcing sheet 322 has a certain degree of elasticity, which not only provides support for the valve plate 321 but also helps the valve plate 321 to spring back and reset.

[0058] In some embodiments, the width of the reinforcing piece 322 is equal to or less than the width of the valve piece 321; the length of the reinforcing piece 322 is less than the length of the valve piece 321.

[0059] In an exemplary embodiment, the length of the reinforcing piece 322 is set to 0.5-0.8 times the length of the valve piece 321; preferably, the length of the reinforcing piece 322 can be set to 60% of the length of the valve piece 321, which is beneficial to the opening and springback reset of the valve piece 321.

[0060] The valve plate 321 has a through first mounting hole, and the distance between the axis of the first mounting hole and the short side of the valve plate 321 is 15%-20% of the length of the valve plate 321. Similarly, the reinforcing plate 322 can have the same first mounting hole at the same position, and the valve plate 31 can have a corresponding threaded hole. The screw passes through the first mounting hole and is screwed into the threaded hole to stack and fix the valve plate 321 and the reinforcing plate 322 onto the valve plate 31. When the screw locks the valve plate 321 and the reinforcing plate 322, when the piston moves away from the valve plate 31, a vacuum is formed in the cylinder. The valve plate 321 of the first one-way valve moves into the cylinder with the screw as the fulcrum, thereby leaving the valve plate 31, and oil and gas enter the cylinder. By reasonably setting the position of the screw, it is beneficial for the valve plate 321 to open and rebound to reset.

[0061] In some embodiments, the valve plate assembly 30 further includes a gasket 33 located on the side of the reinforcing plate 322 facing away from the valve plate 321; the gasket 33 has rounded edges, with the rounded edges located near the reinforcing plate 322; the radius of the rounded edges is set to 0.5mm-1mm. The gasket 33 is positioned between the screw and the reinforcing plate 322 to assist the screw in fixing the valve plate 321 and the reinforcing plate 322 to the valve plate 31, preventing the screw from damaging the reinforcing plate 322 and the valve plate 321. Specifically, the gasket 33 can be made of 304 stainless steel, with a thickness of 0.8mm-1mm, and its projected shape can be square, with its single-side width matching the width of the short side of the reinforcing plate 322. The edge of the gasket 33 facing the reinforcing plate 322 can be rounded, with a radius of 0.5mm-1mm; this reduces obstruction to the opening of the valve plate 321, and the optimal value of the rounded edge radius is consistent with the thickness of the gasket 33. When the screw is fastened to the valve plate 31, thread fastening adhesive can be applied to the threaded surface to prevent the screw from loosening.

[0062] In some embodiments, the valve plate 31 is provided with a first boss 313, which extends along the side away from the cylinder body; a second air outlet 312 penetrates the first boss 313, and a transition hole 314 is provided on the first boss 313, with the axis of the second air outlet 312 parallel to the axis of the transition hole 314; a second groove 315 is provided on the plane of the side of the first boss 313 away from the cylinder body, which is arranged circumferentially along the first boss 313, and the second air outlet 312 and the transition hole 314 are both located within the range of the second groove 315; a second sealing ring is provided in the second groove 315. The oil and gas recovery pump provided in the embodiments of the present invention may include a gland, which forms a sealed connection when the gland is pressed against the second sealing ring to prevent the oil and gas discharged from the cylinder body from escaping and mixing with the oil and gas before entering the cylinder body, thus causing the oil and gas recovery pump to consume operating power.

[0063] In some embodiments, the second air outlet 312 includes a first sub-outlet and a second sub-outlet coaxially connected to the first sub-outlet. The first sub-outlet is located near the cylinder block, and its area is larger than that of the second sub-outlet; the area of ​​the second sub-outlet is larger than that of the second air inlet 311. Enlarging the first sub-outlet reduces air outlet resistance. Setting the area of ​​the second sub-outlet smaller than that of the first sub-outlet facilitates the fabrication of the valve plate 321 of the second one-way valve. Setting the area of ​​the second sub-outlet larger than that of the second air inlet 311 helps reduce the operating power of the oil and gas recovery pump. The second air inlet 311 is a circular hole, and the second sub-outlet is enlarged into an elliptical shape.

[0064] In some embodiments, the valve plate 31 is provided with a pressure relief hole 316, the axis of which is perpendicular to the axis of the transition hole 314 and is connected to the transition hole 314; the transition hole 314 is provided with a first vent hole 317, which passes through the first boss 313 and is axially connected to the transition hole 314; the first vent hole 317 is used to communicate with the venting channel on the housing; the valve plate 31 is provided with a second mounting hole 318, which is axially connected to the pressure relief hole 316, and a pressure relief valve 34 is provided in the second mounting hole 318 to discharge a portion of the oil and gas discharged through the second vent 312 and the one-way valve 32 through the pressure relief hole 316 when the pressure exceeds the preset pressure. A recessed space corresponding to the first boss 313 can be provided on the gland to allow the oil and gas discharged from the cylinder to be released slowly and enter the exhaust passage on the housing through the transition hole 314. When the oil and gas discharged from the cylinder exceeds the preset pressure, the pressure relief valve 34 opens, and a portion of the oil and gas enters the pressure relief hole 316 and is discharged through the pressure relief valve 34 to achieve pressure release. Therefore, the transition hole 314 is equivalent to a three-way connector, and the overall structure is compact through clever design. Since the valve plate 31 is located in the first cavity 151 and the first cavity 151 is connected to the intake passage 13, the oil and gas discharged from the pressure relief valve 34 directly enters the first cavity 151 and is circulated again to be recovered into the oil and gas recovery pipe.

[0065] In some embodiments, the pressure relief valve 34 includes: an adjusting nut 341, a spring 342, and a steel ball 343. The two ends of the spring 342 are in contact with the adjusting nut 341 and the steel ball 343, respectively. A tapered hole is provided between the second mounting hole 318 and the pressure relief hole 316. The small end of the tapered hole is connected to the pressure relief hole 316, and the large end of the tapered hole is connected to the second mounting hole 318. The steel ball 343 is embedded in the tapered hole. An internal threaded hole is provided at the end of the second mounting hole 318 away from the pressure relief hole 316, and the adjusting nut 341 is provided with an external thread that is adapted to the internal threaded hole. Specifically, the steel ball 343 can be made of GCr15 material with a surface hardness greater than HRC50. The steel ball 343 is embedded in the conical bore, and its engagement with the inclined surface of the bore results in a blockage. When the pressure adjusting nut 341 is screwed in, its end face presses against the spring 342, which in turn pushes the steel ball 343 into the conical bore, blocking the pressure relief hole 316. When the oil and gas discharged from the cylinder exceeds the preset pressure, the pressure pushes the steel ball 343, compressing the spring 342. The steel ball 343 then disengages from the pressure relief hole 316, and some of the oil and gas enters the hole and exits through the second mounting hole 318 and the through-hole of the pressure adjusting nut 341, thus releasing the oil and gas pressure. By adjusting the position of the pressure adjusting nut 341, the maximum operating pressure of the oil and gas recovery pump can be adjusted. The conical bore serves as a guide during the process of the steel ball 343 closing the pressure relief hole 316.

[0066] In some embodiments, such as Figures 12-13 As shown, the piston assembly 20 specifically includes a cylinder 21 and a piston assembly 22. The cylinder 21 is a hollow cylindrical shape; a portion of the piston assembly 22 is located inside the cylinder 21, and the piston assembly 22 is configured to move along the axial direction of the cylinder 21; wherein, the piston assembly 22 includes a piston ring 225, the piston ring 225 has a trumpet-shaped sidewall, and the piston ring 225 is slidably connected to the inner wall of the cylinder 21, and at least a portion of the sidewall of the piston ring 225 at its large end is in contact with the inner wall of the cylinder 21 to block oil and gas on one side of the piston assembly 22. Piston ring 225 can be made of a material with a certain degree of elasticity. When the side wall of piston ring 225 is flared, piston ring 225 slides along the inner wall of cylinder 21. When the side wall at its large end is pressed against the inner wall of cylinder 21, it can exhibit a slight inward contraction deformation to reduce the frictional resistance between piston ring 225 and cylinder 21 and the resulting mutual wear. This can delay the wear of piston ring 225 and prevent cylinder 21 from being worn through, thus extending the service life of piston assembly 20. It can also effectively maintain the vacuum in the cylinder and improve the return gas capacity of the oil-gas recovery pump.

[0067] In some embodiments, the base material of the cylinder body 21 can be aluminum alloy or stainless steel. Specifically, aluminum alloy grade 6061 can be used, while aluminum alloy grade 7075 can be used for applications with harsh operating environments. For example, when aluminum alloy is used as the base material, its surface can be plated with a NiP coating with a surface roughness Ra0.4. When the base material of the cylinder body 21 is stainless steel, the preferred grade is 0Cr17Ni4Cu4Nb. The surface can be uncoated, and heat treatment can be performed to ensure that the surface hardness of the inner wall reaches HRC45 or higher, with a surface roughness Ra0.4. This can improve the wear resistance of the cylinder body 21.

[0068] In some embodiments, the piston assembly 22 further includes a pressure plate 221 and a connecting rod. The connecting rod includes a bushing 224 and a support body 223 connected to the bushing 224. The axis of the bushing 224 is perpendicular to the axis of the support body 223, and the axis of the support body 223 is parallel to the axis of the cylinder 21. The bushing 224 has a through mounting hole for mounting a transmission mechanism to drive the piston assembly 22 to move axially along the cylinder 21. A piston ring 225 is located between the pressure plate 221 and the connecting rod, and one end of the pressure plate 221 passes through the piston ring 225. The pressure plate 221 and the support body 223 are connected and fixed by threaded fasteners to fix the relative position of the piston ring 225 between the pressure plate 221 and the connecting rod. A countersunk hole can be provided in the center of the pressure plate 221, and a corresponding threaded hole can be provided on the support body 223. The countersunk screw is inserted into the countersunk hole and screwed into the threaded hole. The piston ring 225 can be clamped between the pressure plate 221 and the connecting rod. For example, the axis of the bushing 224 is set to be horizontal, and the axis of the support body 223 is vertical. Therefore, the piston assembly 22 is driven to make vertical up-and-down reciprocating motion in the cylinder 21 through the transmission mechanism.

[0069] In some embodiments, the piston ring 225 includes a base plate connected to the small end of the sidewall, and the angle α between the sidewall and the base plate is set to be greater than 90 degrees. The sidewall is inclined outward relative to the base plate, which allows a portion of the sidewall to contact the inner wall of the cylinder 21, thereby reducing frictional resistance and achieving a better seal between the sidewall and the inner wall of the cylinder 21.

[0070] In an exemplary embodiment, the angle α between the sidewall and the bottom plate is set to 110-120 degrees. For example, the angle α between the sidewall and the bottom plate is set to 112-115 degrees, which reduces frictional resistance while ensuring a good seal between the sidewall and the inner wall of the cylinder 21.

[0071] In some embodiments, the thickness d of the sidewall is set to 0.5-1mm. Preferably, the thickness d of the sidewall is set to 0.6mm. When the thickness d of the sidewall is designed to be too thick or too thin, it is not conducive to achieving the ideal state of slight inward shrinkage deformation caused by the sidewall being squeezed against the inner wall of the cylinder 21.

[0072] In some embodiments, the piston ring 225 includes a layer of composite material with polytetrafluoroethylene (PTFE) as the matrix and graphite added. For example, the height of the piston ring can be set to 3.5 mm. Specifically, the piston ring material can be PTFE with added graphite, and the amount of graphite added can be adjusted within the range of 15%-25%; preferably, the amount of graphite added is 17%. Therefore, the piston ring has the characteristics of self-lubrication, wear resistance, and good sealing performance, which can reduce friction during operation. At the same time, the PTFE matrix has a certain capacity to contain particulate foreign objects that invade the pump, and hard foreign objects can be embedded in the PTFE and become part of the piston ring.

[0073] In some embodiments, the base plate has a through hole 23, and the inner diameter of the side wall is larger than the first hole; the support body 223 has a second hole 24 at the end away from the bushing 224; the pressure plate 221 has a boss that extends axially along the pressure plate 221; wherein the pressure plate 221 is located inside the side wall, and the boss passes through the first hole 23 and is embedded in the second hole 24. The pressure plate 221 sinks into the side wall, which can reduce the height of the piston assembly, and effectively increase the working stroke of the piston assembly while keeping the height of the cylinder 21 unchanged; the boss passing through the first hole 23 and being embedded in the second hole 24 can realize the positioning of the pressure plate 221 on the support body 223, which is convenient for installation and also facilitates the clamping of the piston ring 225.

[0074] In some embodiments, the support body 223 is provided with a groove located on the bottom surface of the second hole; the pressure plate 221 is provided with a protrusion 25 located on the top surface near the boss, and the protrusion 25 is embedded in the groove. By embedding the protrusion 25 in the groove, the pressure plate 221 can be positioned on the support body 223, which facilitates installation and also prevents the piston ring 225 from rotating during the piston device's operation.

[0075] In some embodiments, the inner wall of the cylinder 21 is provided with a coating, the thickness of which is 0.005mm-0.012mm. By providing a coating on the inner wall of the cylinder 21, wear resistance can be improved, thereby extending the service life of the cylinder 21.

[0076] In some embodiments, such as Figure 1 , Figure 2 , Figures 14-16 As shown, the transmission mechanism 40 specifically includes: a crankshaft assembly, a drive shaft 44, a first screw 45, and a second screw 46, etc. The drive shaft 44 has a through-hole internal thread. The first screw 45 and the second screw 46 can be screwed into the internal thread hole from both ends of the drive shaft 44, respectively. The crankshaft assembly can be fixed to one end of the drive shaft 44 by the first screw 45, and the coupling device 60 can be fixed to the other end of the drive shaft 44 by the second screw 46. A main bearing can be fitted on the drive shaft 44. The main bearing can be installed in the mounting hole on the housing 10. The main bearing can be located on the side of the housing 10 closer to the motor 70. The drive shaft 44 can be installed on the housing 10 through the main bearing and a stop, etc., and the inner ring of the drive shaft 44 can be rotatedly connected to the main bearing. Therefore, the entire crankshaft assembly is supported by the main bearing and has a cantilever structure. The rotation axes of the crankshaft assembly and the drive shaft 44 are located on the same axis, which simplifies the design of each component and reduces the weight of the pump head.

[0077] In some embodiments, the crankshaft assembly may include a crankshaft 41, a crank 42, and a counterweight 43. The crankshaft 41 includes a cylindrical positioning part 411 at its end and a cylindrical long shaft section 412 extending concentrically along the axial direction of the positioning part 411. The diameter of the positioning part 411 is larger than the diameter of the long shaft section 412, forming a stepped shaft shape. A tangent plane 413 is provided on the circumferential outer periphery of the long shaft section 412 along its axial direction. The tangent plane 413 is parallel to the axis of the positioning part 411. The crank 42 includes a cylindrical connecting part 421 and a cylindrical shoulder part 422 connected to one side of the connecting part 421 along its axial direction. The diameter of the shoulder part 422 is larger than that of the connecting part 421, forming a stepped shaft shape with the connecting part 421. A third mounting hole 423 is provided through the crank 42 along its axial direction. The third mounting hole 423 is eccentrically positioned, and the side away from the axis of the crank 42 is a straight surface. The straight surface is adapted to the tangent plane 413 to realize the mating connection between the crank 42 and the crankshaft 41. The counterweight 43 has a fourth mounting hole 431. One side of the fourth mounting hole 431 is a flat surface, which matches the tangent plane 413 to achieve a mating connection between the counterweight 43 and the crankshaft 41. The fourth mounting hole 431 is eccentrically positioned, and the flat surface of the fourth mounting hole 431 is positioned close to and facing the center of the counterweight 43. The crank 42 and the counterweight 43 are fitted onto the long shaft section 412 of the crankshaft 41, with the counterweight 43 close to the positioning part 411, i.e., the counterweight 43 is located between the crank 42 and the positioning part 411. A piston bearing is fitted onto the connecting part 421 of the crank 42. The piston bearing is installed in the mounting hole of the piston assembly 22, and the piston assembly 22 is mounted on the crank through the piston bearing. The crank 42 and the inner ring of the piston bearing can be rotatably connected. In this embodiment of the invention, the pump head employs a dual-piston device to share the vacuuming process, and the two cylinders 21 are symmetrically arranged with respect to the rotation axis of the transmission mechanism 40. Therefore, the two cranks 42 are located sequentially between the counterweight 43 and the transmission shaft 44. This design simplifies the structure of each component of the crankshaft assembly, reduces the overall machining process and production cost of the crankshaft assembly, and the design of the tangential plane 413 of the crankshaft 41 enables the transmission of torque to components such as the cranks 42 and the counterweight 43 without the splines, further simplifying the overall structure of the crankshaft assembly.

[0078] In some embodiments, in order to better fix the crankshaft assembly and transmit torque to the crankshaft assembly, the end of the drive shaft 44 away from the motor 70 may be provided with a fifth mounting hole. The fifth mounting hole may be provided with a flat surface, which is adapted to the cutting plane 413 to realize the mating connection between the drive shaft 44 and the crankshaft 41, so as to transmit torque. A counterweight 43 and two cranks 42 are sequentially fitted on the long shaft section 412 of the crankshaft 41, and then one end of the long shaft section 412 is inserted into the fifth mounting hole of the drive shaft 44. The first screw 45 passes through the crankshaft 41 and is screwed into the internal thread hole of the drive shaft 44 to realize the transmission of torque to the crankshaft assembly.

[0079] In some embodiments, the eccentricity of the third mounting hole 423 is adjustable, and the eccentricity of the third mounting hole 423 is the distance between the third mounting hole 423 and the axis of the crank 42. In practical applications, the eccentricity can be adaptively adjusted according to different parameter requirements of the oil and gas recovery pump to meet the needs of more users. For example, the eccentricity can be adjusted between 3mm and 3.75mm. When the power of the oil and gas recovery pump is large, a larger eccentricity such as 3.75mm can be selected; when the power of the oil and gas recovery pump is small, a smaller eccentricity such as 3mm can be selected. Preferably, the eccentricity is set to 3.5mm.

[0080] In some embodiments, a hollow structure is provided around the third mounting hole 423. Under the premise of ensuring the strength of the crank 42 and its normal operation, the hollow structure can be of any shape and any position. The purpose of the hollow structure is to save materials and reduce the weight of the crank 42. For example, the hollow structure includes a through weight-reducing hole 424 and two through grooves. The through grooves include through groove one 425a and through groove two 425b, which are respectively ivory-shaped. The center of the weight-reducing hole 424 is on the central symmetry line of the third mounting hole 423, and through groove one 425a and through groove two 425b are symmetrically distributed at both ends of the central symmetry line of the third mounting hole 423.

[0081] In some embodiments, the counterweight 43 can be of any shape, such as cylindrical, disc-shaped, or semi-circular, depending on the actual application requirements. For example, the counterweight 43 is cylindrical, and a weight adjustment hole 432 can be opened on it as needed. The weight adjustment hole 432 can be set at any position, preferably on both sides of the axis of the counterweight 43, respectively, as the fourth mounting hole 431. By mounting the counterweight 43 on the crankshaft 41 with the counterweight 43 designed in this way, the rotation of the crankshaft assembly can be made more stable, thereby reducing the vibration generated by the oil and gas recovery pump during operation and effectively improving the performance and life of the oil and gas recovery pump.

[0082] The working principle of the transmission mechanism 40 is as follows: the motor 70 drives the transmission shaft 44 to rotate through the coupling device 60, and transmits torque to the crank 42 through the crankshaft 41, driving the two piston assemblies 22 to move axially along the cylinder body; the long shaft section 412 of the crankshaft 41 has only one cutting plane 413. During assembly, the cutting plane 413 is oriented towards the cylinder body 21, and the two cranks 42 are successively fitted onto the counterweight 43 and the transmission shaft 44. The piston bearing is fitted onto the connecting part 421 of the crank 42, and then the assembled piston assembly 22 is fitted onto the piston bearing. Since the third mounting hole 423 on the crank 42 has an eccentricity, one of the two piston assemblies 22 is in a vacuum state and the other is in a venting state. Therefore, the transmission mechanism 40 can generate two vacuum actions every one revolution.

[0083] A second aspect of the present invention provides an oil and gas recovery pump, such as Figure 21 and Figure 22 As shown, it includes: a pump head, a coupling device 60, and a motor 70. One end of the coupling device 60 is fixedly connected to a transmission mechanism; the motor 70 includes a connecting end cover 50, which is fixedly connected to the housing 10; the output shaft of the motor 70 is fixedly connected to the other end of the coupling device 60. A fan may be arranged between the pump head and the motor 70 for heat dissipation, or a fan may not be installed. For example... Figures 17-19 As shown, the connecting end cover 50 and the housing 10 can be directly connected and fixed. The connecting end cover 50 can be provided with a third hole 543 and a fourth hole 544 distributed circumferentially. The third hole 543 can be used to connect and fix the connecting end cover 50 and the housing 10 with threaded fasteners. The motor 70 can also include a housing 71, on which a protrusion 72 can be provided. The fourth hole 544 can be used to connect and fix the connecting end cover 50 and the protrusion 72 with threaded fasteners. The third hole 543 and the fourth hole 544 are staggered and can be set to be non-uniformly distributed circumferentially. An arc-shaped notch can be opened between the third holes 543 and an arc-shaped notch 55 can be opened between the fourth holes 544. Compared with the traditional structure of motor flange with holes evenly distributed on the circumference, this structure can reduce the weight of the connecting end cover 50, thereby reducing the size of the motor 70 and pump head of the oil and gas recovery pump, making the overall size of the oil and gas recovery pump smaller and the overall appearance more beautiful, while ensuring the stable operation of the oil and gas recovery pump.

[0084] In an exemplary embodiment, the connecting end cap 50 may include an annular connecting body 51 and a motor connecting body 52 and a pump head connecting body 53 protruding from opposite sides of the connecting body 51. A plurality of positioning connecting portions 54 protrude from the outer circular surface of the connecting body 51. The positioning connecting portions 54 may be non-uniformly distributed circumferentially, and each positioning connecting portion 54 has a third hole 543 and a fourth hole 544. Since the plurality of positioning connecting portions 54 are non-uniformly distributed on the outer circular surface of the connecting body 51, and an arc-shaped notch 55 is formed between adjacent positioning connecting portions 54, the arc-shaped notch 55 not only prevents assembly interference but also reduces the weight of the connecting end cap 50. The motor connecting body 52 is inserted into the housing 71 to provide positioning, thereby improving the overall stability of the motor. Similarly, the pump head connecting body 53 is inserted into the housing 10.

[0085] In some embodiments, the positioning connection portion 54 includes a first lug 541 and a second lug 542 connected to one side of the first lug 541. The first lug 541 may be triangular, and the second lug 542 may be square. Of course, both the first lug 541 and the second lug 542 may be trapezoidal, semi-circular, or fan-shaped, etc., and no further limitations are made here. The first lug 541 may be provided with a third hole 543, and the second lug 542 may be provided with a fourth hole 544.

[0086] In some embodiments, the thickness of the second lug 542 is 4.5mm-5.5mm, preferably 5mm, and the thickness of the first lug 541 is 7.5mm-8.5mm, preferably 8mm. The thickness difference between the first lug 541 and the second lug 542 is 2mm-4mm, preferably 3mm. The portion of the first lug 541 that is thicker than the second lug 542 protrudes towards the motor connector 52.

[0087] In some embodiments, the number of positioning connection parts 54 can be odd or even, and can be set as needed in actual applications, such as two, four, six, or three, five, seven, etc.; and the positioning connection parts 54 are not uniformly distributed.

[0088] In some embodiments, the number of positioning connection parts 54 is four, and the circumferential distribution positions of the third hole 543 and the fourth hole 544 are symmetrically arranged with respect to the X-axis, or symmetrically arranged with respect to the Y-axis, or symmetrically arranged with respect to both the X-axis and the Y-axis.

[0089] In an exemplary embodiment, such as Figure 19 As shown, the four positioning connection parts 54 are symmetrically arranged with respect to the X-axis and Y-axis; the line connecting the center of the third hole 543 and the center of the connecting body 51 makes an angle α with the X-axis; the line connecting the center of the fourth hole 544 and the center of the connecting body 51 makes an angle β with the Y-axis; wherein, α is 40°-50°, preferably 45°; β is 20°-30°, preferably 25°.

[0090] In some embodiments, the motor 70 further includes an output shaft 73. One end of the output shaft 73 passes through and protrudes from the connecting end cover 50, and the output shaft 73 is supported and mounted on the connecting end cover 50 by bearings. The other end of the output shaft 73 is supported and mounted on the housing 71 by bearings. The motor body is located between the two bearings, and the motor body may include components such as a stator and a rotor. A gap is provided between the connecting end cover 50 and the motor body to provide insulation and prevent interference. The housing 71 may be provided with an explosion-proof connector with a through hole that aligns with the gap, facilitating the introduction of the motor cable into the housing 71 through the through hole. The gap also provides space for the motor cable. When the connecting end cover 50 is removed, the motor cable can be connected to the terminals on the control board of the motor body, enabling routine maintenance of the motor body. Therefore, the design of the connecting end cover 50 reduces the overall weight of the motor 70, making it easy to disassemble, assemble, and maintain. Motor cables typically consist of power and control wires. Both power and control wires can be sequentially wrapped with an insulating layer and a shielding layer, preventing signal interference even when passing through a through-hole. By combining the power and control wires into one, only an explosion-proof flexible conduit is needed to protect the motor cable and route it to the power supply or control cabinet. This not only simplifies installation and reduces the need for explosion-proof materials but also effectively ensures the safety and stability of motor operation.

[0091] In some embodiments, such as Figure 20 and Figure 21 As shown, the coupling device 60 may include a first coupling 61, a second coupling 62, and a flexible element located between the first coupling 61 and the second coupling 62. The flexible component can be, for example, a rubber gasket 63; one end of the first coupling 61 is a motor connecting sleeve 611, which is connected to the output shaft 73 of the motor, and the other end is a first flange 612, on which multiple protruding first claws 613 are provided; one end of the second coupling 62 is a pump head connecting sleeve 621, which is connected to the drive shaft 44 of the pump head, and the other end is a second flange 622, on which multiple protruding second claws 623 are provided; the rubber gasket 63 is disposed between the first flange 612 and the second flange 622, and the rubber gasket 63 has multiple through holes, the positions of which correspond to the positions of the first claws 613 and the second claws 623 respectively; the first claws 613 and the second claws 623 are inserted from both sides of the rubber gasket 63 into the corresponding through holes on the rubber gasket 63, and the first flange 612 and the second flange 622 are tightly fitted with the rubber gasket 63.

[0092] The coupling device in this embodiment of the invention is a split type, with two couplings each connected to the output shaft of the motor and the drive shaft of the pump head. The connection between the two split couplings is achieved by setting irregularly shaped claws on the opposite end faces of the two couplings, with each claw embedding a rubber gasket. When the flexible component is a rubber gasket, it has a certain elastic deformation capability. Compared to a rigid metal connection, connecting the two couplings with a rubber gasket reduces the possibility of damage to mechanical parts while ensuring the transmission of motor torque. This connection method in this embodiment of the invention makes it easier to separate the motor and pump head; the motor can remain unchanged, and the cables connected to the motor can also remain the same, simply by separating the two couplings.

[0093] Optionally, according to an embodiment of the present invention, the rubber gasket 63 serves to buffer the preload between the two flange faces and protect the mechanical components. The thickness of the rubber gasket 63 can be adjusted according to actual needs. When the lengths of the first claw 613 and the second claw 623 are both greater than the thickness of the rubber gasket 63, the second claw 623 will pass through the through hole of the rubber gasket 63 and extend to the first flange 612. Similarly, the first claw 613 will also pass through the through hole of the rubber gasket 63 and extend to the second flange 622. At this time, if no accommodating space is provided at the position where the claws extend from each other, the two flange faces will be pressed against each other's claws, resulting in the two flange faces not being able to fit tightly together. The gap in the middle will make the connection of the two couplings unstable, and the coupling function of this coupling device will not be achieved. Therefore, the first flange 612 has multiple first receiving spaces at the corresponding positions of the second claw 623 to accommodate the second claw 623; the second flange 622 has multiple second receiving spaces at the corresponding positions of the first claw 613 to accommodate the first claw 613. The claws extending to the other flange can extend into the receiving spaces provided on the flange, so that the two flanges fit tightly together, enabling the first coupling 61 and the second coupling 62 to achieve coaxial transmission.

[0094] Optionally, according to an embodiment of the present invention, the number of first claws 613 on the first flange 612 is three, and the first claws 613 are evenly distributed circumferentially on the first flange 612, that is, the central angle between two adjacent first claws is 120°. Similarly, the number of second claws 623 is three, and the three second claws 623 are evenly distributed circumferentially on the second flange 622, that is, the central angle between two adjacent second claws is 120°; and the distribution circle diameter of the first claws 613 and the second claws 623 can be set to be the same and concentrically arranged. When the first claws 613 and the second claws 623 are respectively inserted into the through holes at corresponding positions on the rubber gasket 63, the first claws 613 can be located between two adjacent second claws 623, that is, the second claws 623 are also located between two adjacent first claws 613, thus making the circumferential dimension of the coupling smaller and the structure more compact, and the distribution of the first claws and the second claws both form a triangle, making the torque transmission more stable. Due to factors such as structural requirements, manufacturing and installation errors, changes in operating temperature, and deformation under load, the two shafts connected by a coupling often cannot be guaranteed to be aligned, resulting in a certain range of relative displacement. If these displacements cannot be compensated, additional loads will be generated on the coupling, shafts, and bearings, and may even cause strong vibrations. Therefore, the concentricity of the distribution circles of the three first claws 613 and the three second claws with the transmission shaft ensures the stability of coaxial transmission. Furthermore, the rubber gasket, being a flexible component, can compensate for a certain degree of relative displacement, thus achieving the stability of coaxial transmission.

[0095] Furthermore, when the first claw 613 and the second claw 623 are distributed as described above, the corresponding first and second accommodating spaces can also be evenly distributed on their respective flanges, thus ensuring the accommodation of claws extending from the opposite flange. According to an embodiment of the present invention, the plurality of first accommodating spaces are multiple arc-shaped openings formed from the edge of the first flange towards the shaft center, and the plurality of second accommodating spaces are multiple arc-shaped openings formed from the edge of the second flange towards the shaft center. The curvature of the arc-shaped openings does not need to be explicitly required, as long as they do not interfere with or collide with the claws extending from the opposite side. Furthermore, the arc-shaped opening design allows for the removal of excess material from the first flange 612 and the second flange 622, thereby reducing the weight of the two couplings.

[0096] Optionally, according to an embodiment of the present invention, each first claw 613 and each second claw 623 has a chamfer at its end, which makes the diameter of the claw end smaller, making it easier to insert into the through hole of the rubber pad 63. In particular, when the diameter of the through hole of the rubber pad 63 is equal to or slightly smaller than the diameter of each claw, after assembly, the rubber pad can form a tight connection with each claw, better protecting the two couplings, extending the service life of the coupling device, and also enhancing the stability of the coaxial transmission.

[0097] In some embodiments, the motor connecting sleeve 611 can be a hollow sleeve with a positioning keyway on its inner wall. The motor output shaft 73 has a matching positioning key. When the motor output shaft 73 is inserted into the motor connecting sleeve 611, torque is transmitted via the key connection. A screw is inserted into the motor connecting sleeve 611 from the first claw 613 side and screwed into the threaded hole of the output shaft 73, thereby securing the first coupling 61 to the output shaft 73 and preventing axial displacement between them. Similarly, the same implementation method can be used to connect and fix the pump head connecting sleeve 621 to the pump head drive shaft 44. A protruding locating key is provided on the outer wall of the pump head connecting sleeve 621, and a notch adapted to the locating key is provided at the end of the drive shaft 44. When the pump head connecting sleeve 621 is inserted into the drive shaft 44, the locating key is engaged in the notch, and the screw is inserted into the pump head connecting sleeve 621 from the side of the second claw 623 and screwed into the threaded hole of the drive shaft 44 to achieve a tight connection between the second coupling 62 and the drive shaft 44, which can prevent axial displacement between the second coupling 62 and the drive shaft 44.

[0098] In this embodiment of the invention, the use of an ultra-thin one-way valve plate reduces the power consumption of the oil and gas recovery pump during operation, and the power of the matching motor can be as low as about 80W; and through a series of lightweight designs, the weight of the whole machine, including the pump head and the motor, can be reduced to about 3.5kg.

[0099] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A pump head, characterized by include: A housing having a hollow receiving cavity, the housing having a first air inlet and a first air outlet located in the same plane; the housing having an air inlet channel communicating with the first air inlet and an air outlet channel communicating with the first air outlet, the axes of the air inlet channel and the air outlet channel being approximately parallel, the axes of the first air inlet and the first air outlet being approximately parallel, and the axes of the air inlet channel and the first air inlet being approximately perpendicular; A piston assembly is disposed within the receiving cavity of the housing, and two piston assemblies are provided; each piston assembly includes a piston component and a cylinder, a portion of the piston component is located within the cylinder, and the piston component is configured to move axially along the cylinder. A valve plate assembly includes a valve plate located on one side of the cylinder body and sealed to one end face of the cylinder body. The valve plate is provided with a second air inlet and a second air outlet. A transmission mechanism is disposed within the receiving cavity of the housing. The transmission mechanism includes a crankshaft assembly and a drive shaft, the rotation axes of the crankshaft assembly and the drive shaft being located on the same axis. The crankshaft assembly is located on one side of the drive shaft, and the drive shaft drives the crankshaft assembly to rotate. A piston assembly is sleeved on the crankshaft assembly, so that the transmission mechanism drives the piston assembly to move along the axial direction of the cylinder towards or away from the valve plate. The transmission mechanism is located between two cylinders, and the two cylinders are symmetrically arranged about the rotation axis of the transmission mechanism. The axes of the two cylinders are the same axis and approximately perpendicular to the rotation axis of the transmission mechanism. The rotation axis of the transmission mechanism is approximately parallel to the axis of the first air intake. A pressure cap is fixedly connected to the first mounting flange of the housing. One side of the pressure cap has a recessed first cavity, and the opposite side of the pressure cap protrudes. The valve plate is located within the first cavity, and the first cavity communicates with the air intake channel. The valve plate is provided with a first boss, which extends along the side away from the cylinder body; the second air outlet passes through the first boss, and the first boss is provided with a transition hole, the axis of the second air outlet being parallel to the axis of the transition hole. The first boss has a second groove on the side of the cylinder body away from the first boss. The second groove is arranged along the circumference of the first boss. The second air outlet and the transition hole are both located within the range of the second groove. A second sealing ring is provided in the second groove. The first cavity is provided with a second protrusion, the shape of which matches the first protrusion. The second protrusion is provided with a recessed second cavity, which is connected to the transition hole. The one-way valve at the second air outlet is located in the second cavity. The second protrusion contacts the second sealing ring to prevent the oil and gas in the first cavity and the second cavity from flowing into each other. The oil and gas pass through the first air inlet and the air inlet channel in sequence, and enter the cylinder body through the second air inlet. They then enter the air outlet channel through the second air outlet and merge in the air outlet channel before entering the first air outlet. The oil and gas in the cylinder body are pushed out through the second air outlet by the piston assembly, enter the second cavity to release pressure, and enter the air outlet channel through the transition hole.

2. The pump head of claim 1, wherein The valve plate assembly also includes: A one-way valve is installed on one side of the valve plate and is located downstream of the direction in which the oil flows through the second air inlet or the second air outlet; the one-way valve includes a valve plate and a reinforcing plate, the valve plate covers the second air inlet or the second air outlet, and the valve plate is located between the reinforcing plate and the valve plate; the thickness of the reinforcing plate is adjustable to adjust the magnitude of the closing or opening pressure of the one-way valve.

3. The pump head of claim 1, wherein The first air inlet and the first air outlet are located on both sides of the transmission mechanism, and the height of the first air inlet is higher than that of the first air outlet. The planes containing the first air inlet and the first air outlet are positioned opposite to the motor mounting surface.

4. The pump head according to claim 2, characterized in that, The housing is provided with a protruding first mounting flange at each end. The end face of the first mounting flange and the end face of the housing are both located on the first mounting surface, which is parallel to the rotation axis of the transmission mechanism. The first mounting surface is provided with a first threaded hole, which is distributed circumferentially and at intervals along the receiving cavity of the housing; the valve plate is provided with a first through hole, which is adapted to the first threaded hole to install the valve plate on the housing; the valve plate is provided with a mounting groove, and one end of the cylinder is embedded in the mounting groove.

5. The pump head of claim 4, wherein, Also includes: The first mounting flange is provided with a second threaded hole, which is distributed at intervals along the circumference of the first mounting flange; the gland is provided with a second through hole, which is adapted to the second threaded hole to install the gland onto the first mounting flange; The circumferential distribution dimension of the second threaded hole is larger than that of the first threaded hole; The first mounting surface is provided with a first groove, which surrounds the inner cavity of the housing and is located between the first threaded hole and the second threaded hole; a first sealing ring is provided in the first groove, and the end face of the pressure cap contacts the first sealing ring to prevent oil and gas in the housing cavity from escaping to the outside atmosphere.

6. The pump head of claim 1, wherein The second air outlet includes a first sub-outlet and a second sub-outlet coaxially connected to the first sub-outlet. The first sub-outlet is located near the cylinder block, and the area of ​​the first sub-outlet is larger than that of the second sub-outlet. The area of ​​the second sub-outlet is larger than that of the second air inlet.

7. The pump head of claim 1, wherein The valve plate is provided with a pressure relief hole, the axis of which is perpendicular to the axis of the transition hole, and the pressure relief hole is connected to the transition hole; The transition hole is provided with a first vent hole, which penetrates the first boss and is axially connected to the transition hole; the first vent hole is used to communicate with the venting channel on the housing. The valve plate is provided with a second mounting hole, which is axially connected to the pressure relief hole. A pressure relief valve is provided in the second mounting hole to discharge a portion of the oil and gas that exceeds the preset pressure through the second air outlet and the one-way valve.

8. The pump head of any of claims 5-7, wherein, The outer surface of the housing is provided with a plurality of spaced-apart first mounting posts, which are used to mount the pump head to fix the relative position of the pump head; or, The outer surface of the gland is provided with a plurality of spaced second mounting posts, which are used to mount the pump head so as to fix the relative position of the pump head.

9. An oil and gas recovery pump, characterized in that, include: The pump head as described in any one of claims 1-8; A coupling device, one end of which is fixedly connected to the transmission mechanism; The motor includes a connecting end cover, which is fixedly connected to the housing; the output shaft of the motor is fixedly connected to the other end of the coupling device.

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