Differential hydraulic diaphragm pump fluid end

Abstract

The utility model discloses a differential type hydraulic diaphragm pump fluid end relates to fluid pump field, including crank mechanism and plunger, and the plunger transmission is connected to crank mechanism, and the crosshead of plunger is located in the plunger cooperation hole of oil seal jar, and the plunger end of plunger is located in pressure balance chamber, and pressure balance chamber is connected with pump liquid line, and the first pressure chamber of pump liquid line and pressure balance chamber is connected with the both ends of pressure equalizer respectively, and the crosshead and plunger end portion are connected through plunger stem portion. The utility model communicates the pressure between pump liquid channel and second pressure chamber, and through the pressure between second pressure chamber and first pressure chamber, can reduce the plunger force that crank is received when driving plunger to carry out horizontal movement greatly.

Description

Technical Field

[0001] This utility model relates to the field of fluid pumps, specifically to a differential hydraulic diaphragm pump hydraulic end. Background Technology

[0002] When the hydraulic diaphragm pump is required to operate at a high inlet pressure, the piston force of the pump is very large during the suction stage. The front end of the connecting rod big end bushing and the rear end of the connecting rod small end bushing are tightly fitted with the eccentric mechanism and the crosshead pin, respectively. In other words, no gap can be formed on the working surface of the pump during the entire cycle of liquid suction and discharge, so the lubricating oil cannot enter. This results in dry friction without oil on the mating surface, leading to high temperature bearing failure.

[0003] The "Diaphragm Pump and Corresponding Method for Metering Fluids" in announcement number CN103688053B is a conventional diaphragm pump that lacks the function of counteracting the plunger force during the liquid suction process. Utility Model Content

[0004] The purpose of this invention is to reduce the plunger force by canceling out the pressure between the first pressure chamber and the second pressure chamber, so that the magnitude of the plunger force is close to the frictional force of the plunger rather than the oil pressure inside the diaphragm pump plus the frictional force. A further purpose of this invention is to enable the diaphragm pump to operate under higher inlet and outlet pressure conditions by canceling out the pressure between the first pressure chamber and the second pressure chamber.

[0005] This utility model achieves the above objectives through the following technical means.

[0006] A differential hydraulic diaphragm pump hydraulic end includes a crankshaft mechanism and a plunger. The crankshaft mechanism is drivenly connected to the plunger. The crosshead of the plunger is located in the crosshead mating part of the oil seal cylinder. The plunger end is located in the pressure balance chamber. The pressure balance chamber is connected to the pump fluid pipeline. The pump fluid pipeline and the first pressure chamber of the pressure balance chamber are respectively connected to the two ends of the pressure balancer. The crosshead and the plunger end are connected through the plunger rod.

[0007] Furthermore, the plunger end divides the pressure balance chamber into a first pressure chamber and a second pressure chamber, and the pressure of the first pressure chamber and the second pressure chamber is not connected.

[0008] Furthermore, the pressure balancing chamber is provided with a second pressure chamber relief valve above the second pressure chamber, and the second pressure chamber is connected to the pressure balancer through an oil replenishment pipeline.

[0009] Furthermore, the pressure balancer includes a left chamber and a right chamber, a second pressure contact chamber is provided between the left chamber and the right chamber, a plurality of liquid flow pipes are provided between the left chamber and the second pressure contact chamber, and a plurality of liquid flow pipes are also provided between the right chamber and the second pressure contact chamber.

[0010] Furthermore, the second pressure contact chamber is provided with a second diaphragm, which blocks the flow of liquid between the left chamber and the right chamber.

[0011] Furthermore, one end of the pump fluid pipeline is configured as an outlet and the other end as an inlet. An outlet valve ball is provided at the outlet, and an inlet valve ball is provided at the inlet.

[0012] Furthermore, a pumping channel is provided between the liquid outlet and the liquid inlet, and the pumping channel is pressure-connected with the first pressure contact chamber, and a first diaphragm is provided in the first pressure contact chamber.

[0013] Furthermore, the diameter of the outlet valve ball is larger than the diameter of the outlet and the pump channel, and the diameter of the inlet valve ball is larger than the diameter of the inlet and the pump channel.

[0014] Furthermore, the pressure balancing chamber is surrounded by a main chamber and a secondary chamber, the crosshead and the crosshead mating part are slidably connected, part of the crosshead is located in the oil seal cylinder cavity, and a hole is provided in the middle of the secondary chamber to mate with the plunger rod.

[0015] Furthermore, the main body and the auxiliary body are connected at their mating openings by body nuts with threads on both the inner and outer sides.

[0016] This utility model has the following beneficial effects: Compared to the comparative technology, which lacks a pressure balancing mechanism and is therefore mostly limited to low-pressure scenarios, this invention connects the pressure between the pump fluid channel and the second pressure chamber, and cancels out the pressure between the second pressure chamber and the first pressure chamber, which can significantly reduce the piston force experienced by the crankshaft mechanism when driving the piston to move horizontally. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model during liquid discharge.

[0018] Figure 2 This is a schematic diagram of the structure of this utility model during liquid absorption.

[0019] Figure 3 This is a schematic diagram of the crankshaft mechanism of this utility model.

[0020] In the diagram, 1-crankshaft mechanism, 11-plunger connecting hole, 12-camshaft, 13-rotation center, 14-crankshaft mechanism wall, 2-plunger, 21-crankshaft mechanism connecting hole, 22-crosshead, 23-plunger rod, 24-plunger end, 3-oil seal cylinder, 31-oil seal cylinder housing, 32-oil seal cylinder cavity, 33-oil seal cylinder cover plate, 34-crosshead mating part, 4-pressure balance chamber, 41-main chamber, 42-secondary chamber, 421-chamber nut, 43-first pressure chamber, 44-second pressure chamber, 45-then... 1. Pressure contact chamber; 46-First diaphragm; 47-Second pressure chamber relief valve; 5-Pump fluid line; 51-Pump fluid channel; 52-Inlet; 53-Inlet valve ball; 54-Outlet; 55-Outlet valve ball; 6-Pressure balancer; 61-Left chamber; 62-Right chamber; 63-Pressure tapping pipe; 64-Relief line; 65-Maintenance oil line; 651-First replenishment oil pressure valve; 652-Second replenishment oil pressure valve; 66-Balance pipe; 67-Safety relief valve; 68-Second diaphragm; 69-Second pressure contact chamber. Detailed Implementation

[0021] Example 1: like Figure 1 and Figure 2 and Figure 3 As shown, this utility model provides a differential hydraulic diaphragm pump hydraulic end. The hydraulic end mainly includes a crankshaft mechanism 1, a plunger 2, a pump fluid pipeline 5, a pressure balance chamber 4, and a pressure balancer 6.

[0022] like Figure 3 As shown, the crankshaft mechanism 1 is a drive mechanism, which internally includes a camshaft 12 for converting rotary motion into reciprocating motion and a rotation center 13. The rotation center 13 is connected to the drive input end to drive the crankshaft mechanism 1, and achieves a transmission connection with the plunger 2 through the plunger connection hole 11 of the crankshaft mechanism 1 and the crankshaft mechanism connection hole 21 provided on the plunger rod 23. The plunger connection hole 11 and the crankshaft mechanism connection hole 21 are hinged, and the crankshaft mechanism connection hole 21 is located on the crosshead. This drives the plunger 2 to perform reciprocating linear motion.

[0023] like Figure 1 and Figure 2As shown, the plunger 2 has a multi-segment structure, including a smaller diameter plunger end 24 at the left end and a larger diameter crosshead 22 at the right end. The plunger end 24 and the crosshead 22 are connected by a plunger rod 23. The plunger 2 is installed in the pressure balance chamber 4 of the oil seal cylinder 3. The cavity formed by the main body 41 and the auxiliary body 42 in the pressure balance chamber 4 confines the plunger end 24 within it, while the plunger rod 23 is confined in a hole provided in the middle of the auxiliary body 42, allowing for horizontal reciprocating motion. The main body 41 and the auxiliary body 42 are connected and fixed by a body nut 421, preventing the main body 41 and the auxiliary body 42 from following the plunger 2 during its horizontal movement.

[0024] The second pressure chamber 44 is the chamber between the end face of the plunger end 24 and the first diaphragm 46. The first pressure chamber 43 is the other end of the chamber formed by the main body 41 and the auxiliary body 42 of the plunger end 24. The first pressure chamber 43 and the second pressure chamber 44 apply opposite pressures to both ends of the plunger end 24, thereby reducing the total resistance experienced by the plunger 2 under the reverse force applied by the first pressure chamber 43 during liquid suction. This allows a portion of the total resistance to be partially offset by the reverse force applied by the second pressure chamber 44. Consequently, the force experienced at the crankshaft mechanism wall 14 of the crankshaft mechanism 1 is reduced, preventing bearing failure.

[0025] The pressure balancing chamber 4 is located within the oil seal cylinder cavity 32 of the oil seal cylinder 3. The plunger rod 23 extends from the auxiliary body 2 and is fixedly connected to the crosshead 22. The crosshead 22, the plunger end 24, and the plunger rod 23 are two separate components, with the plunger end 24 and the plunger rod 23 being integral. The crosshead 22 slides into a crosshead mating part 34 provided on the oil seal cylinder 3, and a dynamic seal is formed between the crosshead 22 and the crosshead mating part 34 to prevent hydraulic oil leakage from the oil seal cylinder cavity 32. The pressure balancing chamber 4 is enclosed within the oil seal cylinder housing 31. An oil seal cylinder cover plate 33 is installed on the oil seal cylinder housing 31.

[0026] The pump fluid pipeline 5 is the main pathway for the diaphragm pump of this invention to draw and discharge liquid. It includes a pump fluid channel 51, an inlet 52, and an outlet 54. An inlet valve ball 53 is provided at the inlet 52, and an outlet valve ball 55 is provided at the outlet 54. The second pressure chamber 44 is connected to the first pressure contact chamber 45. A first diaphragm 46 is provided in the first pressure contact chamber 45. The flexible first diaphragm 46 isolates the second pressure chamber 44 from the pump fluid channel 51 through the medium. However, through the first diaphragm 46, the pressure in the second pressure chamber 44 is equal to that in the pump fluid channel 51.

[0027] During the operation of the diaphragm pump, the inlet valve ball 53 and the outlet valve ball 55 ensure that only the inlet 52 remains open when the diaphragm pump is drawing in liquid, and only the outlet 54 remains open when the pump is discharging liquid. When the diaphragm pump is drawing in liquid, the inlet valve ball 53 remains open at the inlet 52, while the outlet valve ball 55 is pressed shut at the pump channel 51 under the pressure of the outlet 54 being greater than the pressure of the inlet 52, blocking the upper opening of the pump channel 51. When the diaphragm pump is drawing in liquid, the inlet valve ball 53 blocks the opening of the inlet 52.

[0028] The pressure balancer 6 is a key component for realizing the pressure dissipation and liquid suction / discharge functions of this invention. The pressure balancer 6 includes a left chamber 61 and a right chamber 62, and a second diaphragm 68 for isolating liquid exchange between the left and right chambers 61 and 62. The outlet 54 of the pump line 5 is connected to the left chamber 61 of the pressure balancer 6 via a pressure tap 63. The right chamber 62 of the pressure balancer 6 is connected to the first pressure chamber 43 via a balance pipe 66. This ensures that the pressure at the outlet 54 is equal to that in the left chamber 61, and that the pressure in the first pressure chamber 43 is equal to that in the right chamber 62.

[0029] To ensure long-term stable operation of the system, auxiliary pipelines are also installed. The oil replenishment pipeline 65 is equipped with a first oil replenishment pressure valve 651 and a second oil replenishment pressure valve 652, which are used to automatically replenish oil in the first pressure chamber 43 and the second pressure chamber 44 when they are short of oil due to minor leaks, respectively. The pressure relief pipeline 64 is equipped with a safety pressure relief valve 67 and a second pressure chamber pressure relief valve 47, providing overpressure protection.

[0030] Example 2: The structure of this embodiment is the same as that of Embodiment 1. It further describes the working principle of the diaphragm pump during the liquid suction and discharge process, as well as how to achieve pressure cancellation.

[0031] like Figure 1 and Figure 2 and Figure 3 As shown, this utility model provides a differential hydraulic diaphragm pump hydraulic end. The hydraulic end mainly includes a crankshaft mechanism 1, a plunger 2, a pump fluid pipeline 5, a pressure balance chamber 4, and a pressure balancer 6.

[0032] like Figure 3As shown, the crankshaft mechanism 1 is a drive mechanism, which internally includes a camshaft 12 for converting rotary motion into reciprocating motion and a rotation center 13. The rotation center 13 is connected to the drive input end to drive the crankshaft mechanism 1, and achieves a transmission connection with the plunger 2 through the plunger connection hole 11 of the crankshaft mechanism 1 and the crankshaft mechanism connection hole 21 provided on the plunger rod 23. The plunger connection hole 11 and the crankshaft mechanism connection hole 21 are hinged, and the crankshaft mechanism connection hole 21 is located on the crosshead. This drives the plunger 2 to perform reciprocating linear motion.

[0033] like Figure 1 and Figure 2 As shown, the plunger 2 has a multi-segment structure, including a smaller diameter plunger end 24 at the left end and a larger diameter crosshead 22 at the right end. The plunger end 24 and the crosshead 22 are connected by a plunger rod 23. The plunger 2 is installed in the pressure balance chamber 4 of the oil seal cylinder 3. The cavity formed by the main body 41 and the auxiliary body 42 in the pressure balance chamber 4 confines the plunger end 24 within it, while the plunger rod 23 is confined in a hole provided in the middle of the auxiliary body 42, allowing for horizontal reciprocating motion. The main body 41 and the auxiliary body 42 are connected and fixed by a body nut 421, preventing the main body 41 and the auxiliary body 42 from following the plunger 2 during its horizontal movement.

[0034] The second pressure chamber 44 is the chamber between the end face of the plunger end 24 and the first diaphragm 46. The first pressure chamber 43 is the other end of the chamber formed by the main body 41 and the auxiliary body 42 of the plunger end 24. The first pressure chamber 43 and the second pressure chamber 44 apply opposite pressures to both ends of the plunger end 24, thereby reducing the total resistance experienced by the plunger 2 under the reverse force applied by the first pressure chamber 43 during liquid suction. This allows a portion of the total resistance to be partially offset by the reverse force applied by the second pressure chamber 44. Consequently, the force experienced at the crankshaft mechanism wall 14 of the crankshaft mechanism 1 is reduced, preventing bearing failure.

[0035] The pump fluid pipeline 5 is the main pathway for the diaphragm pump of this invention to draw and discharge liquid. It includes a pump fluid channel 51, an inlet 52, and an outlet 54. An inlet valve ball 53 is provided at the inlet 52, and an outlet valve ball 55 is provided at the outlet 54. The second pressure chamber 44 is connected to the first pressure contact chamber 45. A first diaphragm 46 is provided in the first pressure contact chamber 45. The flexible first diaphragm 46 isolates the second pressure chamber 44 from the pump fluid channel 51 through the medium. However, through the first diaphragm 46, the pressure in the second pressure chamber 44 is equal to that in the pump fluid channel 51.

[0036] During the operation of the diaphragm pump, the inlet valve ball 53 and the outlet valve ball 55 ensure that only the inlet 52 remains open when the diaphragm pump is drawing in liquid, and only the outlet 54 remains open when the pump is discharging liquid. When the diaphragm pump is drawing in liquid, the inlet valve ball 53 remains open at the inlet 52, while the outlet valve ball 55 is pressed shut at the pump channel 51 under the pressure of the outlet 54 being greater than the pressure of the inlet 52, blocking the upper opening of the pump channel 51. When the diaphragm pump is drawing in liquid, the inlet valve ball 53 blocks the opening of the inlet 52.

[0037] The pressure balancer 6 is a key component for realizing the pressure dissipation and liquid suction / discharge functions of this invention. The pressure balancer 6 includes a left chamber 61 and a right chamber 62, and a second diaphragm 68 for isolating liquid exchange between the left and right chambers 61 and 62. The outlet 54 of the pump line 5 is connected to the left chamber 61 of the pressure balancer 6 via a pressure tap 63. The right chamber 62 of the pressure balancer 6 is connected to the first pressure chamber 43 via a balance pipe 66. This ensures that the pressure at the outlet 54 is equal to that in the left chamber 61, and that the pressure in the first pressure chamber 43 is equal to that in the right chamber 62.

[0038] To ensure long-term stable operation of the system, auxiliary pipelines are also installed. The oil replenishment pipeline 65 is equipped with a first oil replenishment pressure valve 651 and a second oil replenishment pressure valve 652, which are used to automatically replenish oil in the first pressure chamber 43 and the second pressure chamber 44 when they are short of oil due to minor leaks, respectively. The pressure relief pipeline 64 is equipped with a safety pressure relief valve 67 and a second pressure chamber pressure relief valve 47, providing overpressure protection.

[0039] This section details the dynamic working process of this invention during the liquid suction stroke. The starting point of the liquid suction process is the instant the liquid discharge stroke ends, i.e., when the plunger 2 is at the leftmost end of its stroke. In this embodiment, the pressure outside the inlet 52 is maintained at P1 during operation, and the pressure outside the outlet 54 is maintained at P2. Furthermore, P2 is greater than P1.

[0040] Before the suction begins, the volume of the second pressure chamber 44 is at its minimum, and its internal pressure is slightly higher than the outlet pressure P2; the first diaphragm 46 is pressed to the leftmost position of the first pressure contact chamber 45, at which time the outlet valve ball 55 is slightly open, and the inlet valve ball 53 is tightly closed due to the high pressure inside the pump; the volume of the first pressure chamber 43 is at its maximum, and its internal pressure is consistent with the outlet pressure P2 through the balance pipe 66 and the pressure balancer 6; the volume of the right chamber 62 of the pressure balancer 6 is at its minimum, and the second diaphragm 68 is pressed to the rightmost position.

[0041] When crankshaft mechanism 1 drives piston 2 to move to the right, the movement of piston 2 to the right directly causes the volume of the second pressure chamber 44 to begin to increase. Since the hydraulic oil inside the chamber is incompressible, the slight increase in volume causes its internal pressure to drop rapidly from a value higher than P2.

[0042] The sudden pressure drop is transmitted to the first pressure contact chamber 45 through the first diaphragm 46. At this time, the constant high pressure P2 at the outlet 54 and the sudden pressure drop in the first pressure contact chamber 45 create a huge pressure difference, instantly closing the outlet valve ball 55. As the pressure increases further, the pressure continues to decrease due to the increase in the volume of the second pressure chamber 44, until the pressure is less than P1. At this point, the inlet valve ball 53 at the inlet 52 is opened, and liquid is drawn into the pump channel 51 until the first diaphragm 46 reaches the rightmost side of the first pressure contact chamber 45.

[0043] The medium begins to flow into the first pressure contact chamber 45 from the inlet 52. Driven by the inlet pressure P1, the first diaphragm 46 closely follows the rightward movement of the plunger 2, always keeping the second pressure chamber 44 between it and the plunger end 24 filled with hydraulic oil. Throughout the suction stroke, the pressure in the second pressure chamber 44 will remain stable at a level slightly lower than P1. It should be noted that the sum of the volumes of the second pressure chamber 44 and the first pressure contact chamber 45, neglecting the elastic deformation of the first diaphragm 46, should be a constant value.

[0044] As the plunger 2 moves to the right, the volume of the first pressure chamber 43 decreases.

[0045] Oil transfer and diaphragm movement: The decrease in volume forces the hydraulic oil in the first pressure chamber 43 to be squeezed into the right chamber 62 of the pressure balancer 6 through the balance pipe 66. During this process, the total volume of the first pressure chamber 43 and the right chamber 62 remains constant when elastic deformation is ignored. The oil flowing into the right chamber 62 pushes the second diaphragm 68 to move to the left, thereby squeezing part of the medium in the left chamber 61 back to the outlet pipeline through the pressure tapping pipe 63, which plays a buffering role in smoothing flow pulsations.

[0046] Force balance: Throughout the liquid suction process, plunger 2 is always subjected to two main hydraulic pressures in opposite directions: one is a rightward thrust F1 generated by the inlet pressure P1 acting on the end face of plunger 24, the magnitude of F1 being equal to P1 multiplied by the area of ​​the smaller end; the other is a leftward balancing force F2 generated by the outlet pressure P2 acting on the annular surface through the balancing system, the magnitude of F2 being equal to P2 multiplied by the area of ​​the smaller end. This ensures that F1 and F2 are approximately equal in magnitude, thus bringing the net fluid pressure transmitted to crankshaft mechanism 1 close to zero. Only friction and inertial forces need to be overcome, achieving a reversal of the force on the connecting rod and facilitating lubrication.

[0047] During normal liquid intake, the pressure in the first pressure chamber 43 is constant at P2, and the pressure in the second pressure chamber 44 is approximately P1. Since P1 and P2 are usually much higher than atmospheric pressure, both the first replenishing pressure valve 651 and the second replenishing pressure valve 652 are reliably closed and do not function. They only open automatically due to the pressure difference when the corresponding chamber expands in volume due to leakage or other reasons (such as the second pressure chamber 44 in this stage), to draw oil from the external oil cup for replenishment, thus ensuring the rigidity of the hydraulic transmission.

[0048] Pressure relief system: The opening pressure of both the safety relief valve 67 and the second pressure chamber relief valve 47 is set to a value much higher than the normal operating pressure P2. During the suction stroke, the pressure at all points in the system is within the normal operating range, so these two relief valves remain closed and do not activate. Their function is to provide passive safety protection in the event of abnormally high system pressure (such as thermal expansion of oil or pipeline blockage), preventing damage to critical components due to overpressure.

[0049] At the initial moment of the discharge stroke, the system states are as follows: the volume of the second pressure chamber 44 is at its maximum value, and its internal pressure is slightly lower than the inlet pressure P1; the first diaphragm 46 is drawn to the rightmost position; the inlet valve ball 53 is in the open state, while the outlet valve ball 55 is tightly closed due to the outlet high pressure P2; the volume of the first pressure chamber 43 is at its minimum value, and its internal pressure is constant at P2 through the balance pipe 66 and the pressure balancer 6; the volume of the right chamber 62 of the pressure balancer 6 is at its maximum value, and the second diaphragm 68 is pressed to the leftmost position.

[0050] When crankshaft mechanism 1 drives plunger 2 to move to the left, the leftward movement of plunger 2 directly causes the volume of the second pressure chamber 44 to decrease. Due to the incompressibility of the hydraulic oil in the chamber, its internal pressure rises instantaneously from a value below P1 to above P2. This pressure is transmitted in real time to the first pressure contact chamber 45 through the first diaphragm 46. The rapid increase in pressure first causes the inlet valve ball 53 to close instantaneously, because the pressure in the pump chamber immediately exceeds the pressure P1 at the inlet 52, thereby cutting off the flow of liquid into the inlet 52.

[0051] As plunger 2 continues to advance to the left, the pressure in the second pressure chamber 44 continuously increases. When this pressure rises to and slightly exceeds the outlet pressure P2 at the outlet 54, the opening force acting on the outlet valve ball 55 overcomes the back pressure of the outlet pipeline, pushing it upwards. At this point, the medium in the first pressure contact chamber 45 finds a passage and is stably discharged into the outlet pipeline under the continuous compression of the first diaphragm 46. Throughout the entire discharge stroke, the pressure in the second pressure chamber 44 will remain stable at a level slightly higher than P2.

[0052] As plunger 2 moves to the left to complete the drainage, the volume of the first pressure chamber 43 increases. To fill this increased volume, the hydraulic oil in the pressure balancer 6 begins to flow in the reverse direction. Specifically, the constant medium pressure P2 in the left chamber 61 of the pressure balancer 6 pushes the second diaphragm 68 to the right, thereby squeezing the hydraulic oil in the right chamber 62 into the expanding first pressure chamber 43 via the balance pipe 66. During this process, the increase in volume of the first pressure chamber 43 is equal to the decrease in volume of the right chamber 62, and the sum of their volumes remains constant. Simultaneously, the left chamber 61 draws in medium from the outlet pipe to replenish the volume occupied by the second diaphragm 68, continuing to perform its flow buffering function.

[0053] Throughout the entire drainage process, the transmission mechanism needs to overcome the net fluid pressure, which is the resultant force acting on the plunger 2. This resultant force consists of two main parts: one is the huge rightward resistance generated by the high pressure P2 in the second pressure chamber 44 acting on the end face of the plunger end 24; the other is the leftward auxiliary thrust generated by the pressure of P2 in the first pressure chamber 43 acting on the annular surface. Therefore, the net compressive force ultimately transmitted to the crankshaft mechanism 1 is reduced, the load on the transmission end is reduced, and the smoothness of operation is improved.

[0054] During this drainage stroke, the system pressure remains within the normal operating range of P2 or slightly above P2. Therefore, the first replenishing pressure valve 651, the second replenishing pressure valve 652, and the related safety relief valves 47 and 67 will not trigger, remaining passively closed. They will only activate their preset automatic replenishing or overpressure protection functions when the system experiences abnormal operating conditions, i.e., when the pressure exceeds P2 significantly.

Claims

1. A differential hydraulic diaphragm pump hydraulic end, characterized in that, It includes a crankshaft mechanism (1) and a plunger (2). The crankshaft mechanism (1) is connected to the plunger (2) in a transmission. The crosshead (22) of the plunger (2) is located in the crosshead mating part (34) of the oil seal cylinder (3). The plunger end (24) of the plunger (2) is located in the pressure balance chamber (4). The pressure balance chamber (4) is connected to the pump fluid line (5). The pump fluid line (5) and the first pressure chamber (43) of the pressure balance chamber (4) are respectively connected to the two ends of the pressure balancer (6). The crosshead (22) and the plunger end (24) are connected through the plunger rod part (23).

2. The hydraulic end of a differential hydraulic diaphragm pump according to claim 1, characterized in that, The plunger end (24) divides the pressure balance chamber (4) into a first pressure chamber (43) and a second pressure chamber (44), and the pressure of the first pressure chamber (43) and the second pressure chamber (44) is not connected.

3. The hydraulic end of a differential hydraulic diaphragm pump according to claim 2, characterized in that, The pressure balancing chamber (4) is provided with a second pressure chamber relief valve (47) above the second pressure chamber (44), and the second pressure chamber (44) is connected to the pressure balancer (6) through the oil replenishment pipeline (65).

4. The hydraulic end of a differential hydraulic diaphragm pump according to claim 1, 2, or 3, characterized in that, The pressure balancer (6) includes a left chamber (61) and a right chamber (62). A second pressure contact chamber (69) is provided between the left chamber (61) and the right chamber (62). Several liquid flow pipes are provided between the left chamber (61) and the second pressure contact chamber (69), and several liquid flow pipes are also provided between the right chamber (62) and the second pressure contact chamber (69).

5. The hydraulic end of a differential hydraulic diaphragm pump according to claim 4, characterized in that, The second pressure contact chamber (69) is provided with a second diaphragm (68), which blocks the flow of liquid between the left chamber (61) and the right chamber (62).

6. The hydraulic end of a differential hydraulic diaphragm pump according to claim 1, 2, 3, or 5, characterized in that, One end of the pump fluid pipeline (5) is configured as an outlet (54) and the other end is configured as an inlet (52). An outlet valve ball (55) is provided at the outlet (54) and an inlet valve ball (53) is provided at the inlet (52).

7. The hydraulic end of a differential hydraulic diaphragm pump according to claim 6, characterized in that, A pumping channel (51) is provided between the liquid outlet (54) and the liquid inlet (52). The pumping channel (51) is pressure-connected with the first pressure contact chamber (45). A first diaphragm (46) is provided in the first pressure contact chamber (45).

8. The hydraulic end of a differential hydraulic diaphragm pump according to claim 7, characterized in that, The diameter of the outlet valve ball (55) is greater than the diameter of the outlet (54) and the pump channel (51), and the diameter of the inlet valve ball (53) is greater than the diameter of the inlet (52) and the pump channel (51).

9. The hydraulic end of a differential hydraulic diaphragm pump according to claim 1, 2, 3, 5, 7, or 8, characterized in that, The pressure balance chamber (4) is surrounded by the secondary chamber (42) by the main chamber (41). The crosshead (22) is slidably connected to the crosshead mating part (34). Part of the crosshead (22) is located in the oil seal cylinder cavity (33). The secondary chamber (42) has a hole in the middle that mates with the plunger rod part (23).

10. The hydraulic end of a differential hydraulic diaphragm pump according to claim 9, characterized in that, The main body (41) and the auxiliary body (42) are connected at their mating openings by a body nut (421) with threads on both the inner and outer sides.

Images