Low-pressure hydraulic diaphragm metering pump

Abstract

The invention provides a low-pressure hydraulic diaphragm metering pump which is characterized by comprising a gear box, a hydraulic oil tank, gear oil, a driving mechanism, a crosshead, a diaphragm, a hydraulic oil cavity, a pump head, a pump head cavity, an inlet one-way valve, an outlet one-way valve, a release valve, an exhaust valve, an oil supplementing valve element and an oil supplementing valve opening judging mechanism. The driving mechanism drives the crosshead to do reciprocating motion, the outer circumference of the diaphragm is pressed by the pump head and the hydraulic oil tank to achieve sealing, the hydraulic oil cavity is formed by the space among the crosshead, the diaphragm and the hydraulic oil tank, and gear oil is contained in the gear box to provide lubrication for the driving mechanism. And meanwhile, the hydraulic oil cavity is filled with the gear oil. According to the low-pressure hydraulic diaphragm metering pump, the structure is compact, the size is small, the filter element of the oil supplementing valve is easy to regenerate, and quick-wear parts of the oil supplementing valve are easy to replace.

Description

Technical Field

[0001] The present invention relates to the technical field of metering pumps, and in particular to a low-pressure hydraulic diaphragm metering pump. Background Art

[0002] In order to ensure long-term stable operation of the entire system, the existing hydraulic diaphragm metering pump usually has a replenishing valve, an exhaust valve, and a release valve in the hydraulic oil chamber. A special hydraulic oil pool is provided to collect the hydraulic oil discharged by the release valve. The replenishing valve also sucks hydraulic oil from the hydraulic oil pool to replenish the hydraulic oil chamber. Usually, the hydraulic oil and gear oil are separated. The advantage is that the contaminants in the gear oil will not contaminate the hydraulic oil, but the disadvantage is that the structure is relatively complicated.

[0003] Usually, a crosshead at the driving end needs to be connected to plungers or pistons of different diameters to obtain different flow rates and pressures. Although it is relatively flexible, the structure is relatively complex and requires a large space.

[0004] Using gear oil as hydraulic oil and eliminating the hydraulic oil pool can greatly simplify the entire product structure. However, it will face new challenges, such as contaminants in the gear oil (sliding bearing wear debris, worm gear wear debris, dust particles smaller than the diameter of the breather valve filter, etc.), which will aggravate the wear of the easily worn structure of the oil replenishment valve.

[0005] Develop a hydraulic diaphragm metering pump with simplified structure and compact size. At the same time, the oil replenishment valve can work normally in non-pure hydraulic oil and is easy to maintain. The main design purpose is to be suitable for low-pressure hydraulic diaphragm metering pumps, which has practical application value. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a low-pressure hydraulic diaphragm metering pump with compact structure and small size, easy regeneration of the oil replenishment valve filter element and easy replacement of the oil replenishment valve wearing parts.

[0007] In order to solve the above technical problems, the present invention provides a low-pressure hydraulic diaphragm metering pump, characterized in that it includes a gear box, a hydraulic oil tank, gear oil, a driving mechanism, a crosshead, a diaphragm, a hydraulic oil chamber, a pump head, a pump head chamber, an inlet check valve, an outlet check valve, a release valve, an exhaust valve, an oil replenishing valve core and an oil replenishing valve opening judgment mechanism, wherein the driving mechanism is arranged in the gear box to drive the crosshead to reciprocate, the outer circumference of the diaphragm is pressed and sealed by the pump head and the hydraulic oil tank, the space between the crosshead, the diaphragm and the hydraulic oil tank forms the hydraulic oil chamber, the gear oil is contained in the gear box to provide lubrication for the driving mechanism, and the gear oil fills the hydraulic oil chamber, the reciprocating motion of the crosshead drives the diaphragm to deform forward and backward through the gear oil in the hydraulic oil chamber, the space between the pump head, the inlet check valve and the outlet check valve forms the pump head chamber, and when the diaphragm deforms backward When the diaphragm is deformed forward, the medium enters the pump head chamber through the inlet check valve. When the diaphragm is deformed forward, the medium in the pump head chamber is discharged from the pump head chamber through the outlet check valve. When the pressure of the hydraulic oil chamber exceeds the set value of the release valve, the release valve is opened to discharge the gear oil in the hydraulic oil chamber into the gear box. The gas in the hydraulic oil chamber can be discharged from the hydraulic oil chamber through the exhaust valve arranged above the hydraulic oil chamber. When the diaphragm is deformed backward to the set position, the oil replenishment valve opening judgment mechanism judges that the oil replenishment valve core can be opened. At this time, the oil replenishment valve core is in a state that can be opened. When the pressure difference between the gear box and the hydraulic oil chamber reaches the set pressure of the oil replenishment valve core, the oil replenishment valve core is opened, and the gear oil in the gear box is replenished into the hydraulic oil chamber under the action of pressure. When the oil replenishment valve opening judgment mechanism does not judge that the oil replenishment valve core can be opened, the oil replenishment valve core cannot be opened.

[0008] Optionally, it includes an L-shaped rocker arm, an L-shaped rocker arm angular hole, a diaphragm position detection plate, a diaphragm position detection plate spring, an oil replenishing valve body and a filter element. The L-shaped rocker arm, the L-shaped rocker arm angular hole, the diaphragm position detection plate and the diaphragm position detection plate spring together constitute the oil replenishing valve opening judgment mechanism. The L-shaped rocker arm can swing around the L-shaped rocker arm angular hole. The oil replenishing valve core is a self-weighted spherical valve. The diaphragm position detection plate spring supports the diaphragm position detection plate. One arm of the L-shaped rocker arm is pulled by the diaphragm position detection plate, and the other arm of the L-shaped rocker arm is pressed on the valve ball of the oil replenishing valve core. When the diaphragm is deformed backward to a set position, the diaphragm position detection plate is pushed to move backward, and the L-shaped rocker arm pressing the oil replenishing valve core is released, and the oil replenishing valve core is in an openable state. The filter element is arranged in the oil replenishing valve body, and the oil replenishing valve body and the oil replenishing valve core can be taken out from the lower part of the hydraulic oil tank.

[0009] Optionally, an L-shaped rocker arm hole is included, and the L-shaped rocker arm and the diaphragm position detection plate are hinged through the L-shaped rocker arm hole.

[0010] Compared with the prior art, the present invention has the following advantages: The hydraulic diaphragm metering pump of the present invention has a compact structure and a small size, and the filter element of the oil replenishing valve is easy to regenerate and the wearing parts of the oil replenishing valve are easy to replace. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which: Figure 1 A top view of a low-pressure hydraulic diaphragm metering pump according to an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of a low-pressure hydraulic diaphragm metering pump along line AA; Implementation

[0012] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0013] Figure 1 This is a top view of a low-pressure hydraulic diaphragm metering pump according to an embodiment of the present invention. Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of a low-pressure hydraulic diaphragm metering pump along line AA. Figure 2As shown, the low-pressure hydraulic diaphragm metering pump may include a gear box 1, a hydraulic oil tank 2, gear oil 3, a driving mechanism 4, a crosshead 5, a diaphragm 6, a hydraulic oil chamber 7, a pump head 8, a pump head chamber 9, an inlet check valve 10, an outlet check valve 11, a release valve 12, an exhaust valve 13, an oil replenishing valve core 14 and an oil replenishing valve opening judgment mechanism 20, wherein the driving mechanism 4 is arranged in the gear box 1, driving the crosshead 5 to make reciprocating motion, the outer circumference of the diaphragm 6 is pressed and sealed by the pump head 8 and the hydraulic oil tank 2, the space between the crosshead 5, the diaphragm 6 and the hydraulic oil tank 2 forms a hydraulic oil chamber 7, the gear oil 3 is contained in the gear box 1 to provide lubrication for the driving mechanism 4, and the gear oil 3 fills the hydraulic oil chamber 7, the reciprocating motion of the crosshead 5 drives the diaphragm 6 to deform forward and backward through the gear oil 3 in the hydraulic oil chamber 7, the space between the pump head 8, the inlet check valve 10 and the outlet check valve 11 forms the pump head chamber 9, and when the diaphragm 6 deforms backward When the diaphragm 6 is deformed forward, the medium enters the pump head chamber 9 through the inlet check valve 10. When the diaphragm 6 is deformed forward, the medium in the pump head chamber 9 is discharged from the pump head chamber 9 through the outlet check valve 11. When the pressure of the hydraulic oil chamber 7 exceeds the set value of the release valve 12, the release valve 12 is opened to discharge the gear oil 3 in the hydraulic oil chamber 7 into the gear box 1. The gas in the hydraulic oil chamber 7 can be discharged from the hydraulic oil chamber 7 through the exhaust valve 13 arranged above the hydraulic oil chamber 7. When the diaphragm 6 is deformed backward to the set position, the oil replenishing valve opening judgment mechanism 20 judges that the oil replenishing valve core 14 can be opened. At this time, the oil replenishing valve core 14 is in a state that can be opened. When the pressure difference between the gear box 1 and the hydraulic oil chamber 7 reaches the set pressure of the oil replenishing valve core 14, the oil replenishing valve core 14 is opened, and the gear oil 3 in the gear box 1 is replenished into the hydraulic oil chamber 7 under the action of pressure. When the oil replenishing valve opening judgment mechanism 20 does not judge that the oil replenishing valve core 14 can be opened, the oil replenishing valve core 14 cannot be opened.

[0014] By using the gear oil 3 as hydraulic oil, a dedicated hydraulic oil tank is saved and the volume of the pump is reduced. By directly using the crosshead 5 as a piston and giving up the need to transfer pistons of different diameters, the volume is further reduced and the structure is simplified.

[0015] The three valves in the hydraulic diaphragm metering, the release valve 12 can protect the pipeline and pump to prevent overpressure in the pipeline, the exhaust valve 13 can discharge the gas in the hydraulic oil chamber 7 to maintain the metering accuracy, and when the oil in the hydraulic oil chamber 7 is insufficient, the oil replenishment valve is opened to replenish the hydraulic oil. It is a more reliable way to replenish oil by detecting the position of the diaphragm 6 to determine whether the oil replenishment valve core 14 can be opened, which can effectively prevent excessive oil replenishment and reduce the risk of rupture of the diaphragm 6.

[0016] The low-pressure hydraulic diaphragm metering pump can also include an L-shaped rocker arm 15, an L-shaped rocker arm angle hole 16, a diaphragm position detection plate 17, a diaphragm position detection plate spring 18, an oil replenishment valve body 21 and a filter element 22. The L-shaped rocker arm 15, the L-shaped rocker arm angle hole 16, the diaphragm position detection plate 17 and the diaphragm position detection plate spring 18 together constitute an oil replenishment valve opening judgment mechanism 20. The L-shaped rocker arm 15 can swing around the L-shaped rocker arm angle hole 16. The oil replenishment valve core 14 is a self-heavy spherical valve. The diaphragm position detection plate spring 18 The spring 18 supports the diaphragm position detection plate 17, one arm of the L-shaped rocker arm 15 is pulled by the diaphragm position detection plate 17, and the other arm of the L-shaped rocker arm 15 is pressed on the valve ball of the oil replenishing valve core 14. When the diaphragm 6 deforms backward to the set position, it pushes the diaphragm position detection plate 17 to move backward, and the L-shaped rocker arm 15 pressing the oil replenishing valve core 14 is released, and the oil replenishing valve core 14 is in an openable state. The filter element 22 is arranged in the oil replenishing valve body 21, and the oil replenishing valve body 21 and the oil replenishing valve core 14 can be taken out from the lower part of the hydraulic oil tank 2.

[0017] For low-pressure applications, the biggest problem with using gear oil 3 as hydraulic oil is that the hydraulic oil cannot be pure. The filter element 22 can reduce the particle diameter of the oil in the hydraulic oil chamber 7 and reduce the harm of pollutants to a certain extent. However, the filter element 22 needs to be regenerated after long-term use, so the filter element 22 needs to be easily removed.

[0018] The oil replenishing valve core 14 adopts a self-weight ball valve, which is arranged vertically, and the spring of the oil replenishing valve core 14 can be eliminated, and the structure is simplified. At the same time, the self-weight ball valve has a self-cleaning function, which is more suitable for polluted working conditions and has a long service life.

[0019] In conventional oil replenishment valves, the diaphragm position probe plate 17 usually slides in the corresponding bushing. When the hydraulic oil is impure, the wear is aggravated, the service life is shortened, and there is a risk of getting stuck. The L-shaped rocker arm 15 swings around the L-shaped rocker arm angle hole 16, and adopts a hinged fit with a large clearance, so that impurities are less likely to get stuck in the friction pair, avoiding severe friction and increasing the service life.

[0020] Conventional replenishing valves with the function of detecting the position of the diaphragm 6 need to open the pump head 8 and remove the diaphragm 6 before replacing the replenishing valve. The L-shaped rocker arm structure in the present invention allows the replenishing valve core 14 to be arranged vertically, and the replenishing valve core 14 and the replenishing valve body 21 can be taken out from the bottom of the hydraulic oil tank 2, making replacement easy. That is, the structure cannot be replaced from the bottom, with less wear and tear and a long service life, and the replenishing valve core 14 and the replenishing valve body 21 that need to be replaced can be easily replaced.

[0021] The filter element 22 is arranged on the oil replenishing valve body 21 and can be conveniently taken out with the oil replenishing valve body 21 for regeneration.

[0022] The low-pressure hydraulic diaphragm metering pump may further include an L-shaped rocker arm hole 19 , through which the L-shaped rocker arm 15 and the diaphragm position detection plate 17 are hinged.

[0023] The motion trajectory of the hinged rocker arm hole 19 is a small arc around the rocker arm corner hole 16, and moves a small distance left and right just above the circle where the arc trajectory is located. The up and down swing displacement is very small, so that the movement of the diaphragm position detection plate 17 is stable.

[0024] The present invention makes the low-pressure hydraulic diaphragm metering pump compact in structure, small in size and low in cost through reasonable structural arrangement and design; and makes the vulnerable parts of the oil replenishing valve easy to replace and the filter element of the oil replenishing valve easy to regenerate through reasonable design of the oil replenishing valve structure.

[0025] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A low-pressure hydraulic diaphragm metering pump, characterized in that: The invention comprises a gear box (1), a hydraulic oil tank (2), gear oil (3), a driving mechanism (4), a crosshead (5), a diaphragm (6), a hydraulic oil chamber (7), a pump head (8), a pump head chamber (9), an inlet check valve (10), an outlet check valve (11), a release valve (12), an exhaust valve (13), an oil replenishment valve core (14), and an oil replenishment valve opening judgment mechanism (20), wherein the driving mechanism (4) is arranged in the gear box (1) and drives the crosshead (5) to perform reciprocating motion, the outer circumference of the diaphragm (6) is pressed by the pump head (8) and the hydraulic oil tank (2) to achieve sealing, and the crosshead ( 5), the space between the diaphragm (6) and the hydraulic oil tank (2) forms the hydraulic oil chamber (7), the gear oil (3) is contained in the gear box (1) to provide lubrication for the drive mechanism (4), and the gear oil (3) fills the hydraulic oil chamber (7). The reciprocating motion of the crosshead (5) drives the diaphragm (6) to deform forward and backward through the gear oil (3) in the hydraulic oil chamber (7), and the space between the pump head (8), the inlet check valve (10) and the outlet check valve (11) forms the pump head chamber (9). When the diaphragm (6) deforms backward, the medium passes through The inlet check valve (10) enters the pump head chamber (9). When the diaphragm (6) deforms forward, the medium in the pump head chamber (9) is discharged from the pump head chamber (9) through the outlet check valve (11). When the pressure in the hydraulic oil chamber (7) exceeds the set value of the release valve (12), the release valve (12) opens to discharge the gear oil (3) in the hydraulic oil chamber (7) into the gear box (1). The gas in the hydraulic oil chamber (7) can be discharged from the hydraulic oil chamber (7) through the exhaust valve (13) arranged above the hydraulic oil chamber (7). When the diaphragm (6) deforms forward, the medium in the pump head chamber (9) is discharged from the pump head chamber (9) through the outlet check valve (11). When the gear box (1) is deformed to the set position, the oil replenishing valve opening judgment mechanism (20) judges that the oil replenishing valve core (14) can be opened. At this time, the oil replenishing valve core (14) is in a state that it can be opened. When the pressure difference between the gear box (1) and the hydraulic oil chamber (7) reaches the set pressure of the oil replenishing valve core (14), the oil replenishing valve core (14) is opened, and the gear oil (3) in the gear box (1) is replenished into the hydraulic oil chamber (7) under the action of pressure. When the oil replenishing valve opening judgment mechanism (20) does not judge that the oil replenishing valve core (14) can be opened, the oil replenishing valve core (14) cannot be opened.

2. A low-pressure hydraulic diaphragm metering pump according to claim 1, characterized in that: The invention comprises an L-shaped rocker arm (15), an L-shaped rocker arm angle hole (16), a diaphragm position detection plate (17), a diaphragm position detection plate spring (18), an oil replenishment valve body (21) and a filter element (22); the L-shaped rocker arm (15), the L-shaped rocker arm angle hole (16), the diaphragm position detection plate (17) and the diaphragm position detection plate spring (18) together constitute the oil replenishment valve opening judgment mechanism (20); the L-shaped rocker arm (15) can swing around the L-shaped rocker arm angle hole (16); the oil replenishment valve core (14) is a self-heavy spherical valve; the diaphragm position detection plate spring (18) supports the diaphragm position detection plate The diaphragm (6) is provided with a plate (17), one arm of the L-shaped rocker arm (15) is pulled by the diaphragm position detection plate (17), and the other arm of the L-shaped rocker arm (15) is pressed on the valve ball of the oil replenishing valve core (14); when the diaphragm (6) is deformed backward to a set position, the diaphragm position detection plate (17) is pushed to move backward, and the L-shaped rocker arm (15) pressing the oil replenishing valve core (14) is released, and the oil replenishing valve core (14) is in an openable state; the filter element (22) is arranged in the oil replenishing valve body (21), and the oil replenishing valve body (21) and the oil replenishing valve core (14) can be removed from the lower part of the hydraulic oil tank (2).

3. A low-pressure hydraulic diaphragm metering pump according to claim 2, characterized in that: It comprises an L-shaped rocker arm hole (19), and the L-shaped rocker arm (15) and the diaphragm position detection plate (17) are hingedly connected through the L-shaped rocker arm hole (19).

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