Leakage-free oil-water separation type plunger pump

Abstract

The invention belongs to the related technical field of plunger pumps, and discloses a leakage-free oil-water separation type plunger pump which comprises a cylinder body, a lining, a large plunger, a small plunger and an elastic sealing piece. A third groove is formed in one end of the cylinder body, a first through hole is formed in the bottom face of the third groove in a penetrating mode, and the first through hole is used for containing the large plunger; one end of the bushing is arranged in the third groove; the small plunger is step-shaped, and a first step surface is formed on the small plunger; one end of the small plunger is positioned in the bushing, and the other end of the small plunger penetrates through the elastic sealing element and then is connected to one end of the large plunger positioned in the cylinder body; the first step face and the large plunger press the middle of the elastic sealing piece to form inner-layer sealing, the lining and the bottom face of the third groove press the outer edge of the elastic sealing piece to form outer-layer sealing, and the inner-layer sealing and the outer-layer sealing are jointly used for isolating a working medium and a lubricating medium which are located on the two opposite sides of the elastic sealing piece respectively. And oil-water mutual seepage is prevented.

Description

Technical Field

[0001] The present invention belongs to the technical field related to plunger pumps, and more specifically, relates to a leak-free oil-water separation plunger pump. Background Art

[0002] Traditional hydraulic systems use mineral oil as their working fluid. While mature, they pose challenges such as environmental pollution, flammability, and high maintenance costs. With stricter environmental regulations and growing demand for green manufacturing, water hydraulics, with its non-toxic, non-flammable medium (pure water or seawater) and low cost, has become a promising alternative.

[0003] As the core power element of hydraulic systems, the performance of pumps has a decisive influence on the development of water hydraulic technology. Due to water's low viscosity and poor lubrication properties, to improve the lubrication environment of the friction pair and enhance the pump's resistance to contamination, most pumps used in water hydraulic systems employ an oil-water separation structure—oil as the lubricating medium and water as the working medium. However, this introduces the problem of sealing the water and oil separately. Existing sealing structures use dynamic seals, which inevitably lead to oil-water interpenetration. This interpenetration is exacerbated by lateral force, tilting the plunger, and seal wear. As the pump operates, the viscosity of the lubricating medium in the drive chamber decreases, causing the friction pair to rapidly wear and fail, shortening the pump's lifespan. Summary of the Invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a leakage-free oil-water separation plunger pump, which aims to solve the problem that oil-water separation plunger pumps are prone to oil-water interpenetration.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present invention, a leakage-free oil-water separation plunger pump is provided, the plunger pump comprising a cylinder body, a bushing, a large plunger, a small plunger and an elastic seal; a third groove is provided at one end of the cylinder body, a first through-hole is provided on the bottom surface of the third groove, and the first through-hole is used to accommodate the large plunger; one end of the bushing is arranged in the third groove; the small plunger is stepped, and a first step surface is formed; one end of the small plunger is located in the bushing, and the other end passes through the elastic seal and is connected to the end of the large plunger located in the cylinder body; the first step surface and the large plunger press the middle part of the elastic seal to form an inner seal, and the bushing and the bottom surface of the third groove press the outer edge of the elastic seal to form an outer seal, and the inner seal and the outer seal are jointly used to isolate the working medium from the lubricating medium respectively located on the opposite sides of the elastic seal.

[0006] Furthermore, two concentrically arranged annular sealing flanges are formed on the same side of the elastic seal, namely a first sealing flange and a second sealing flange; the first sealing flange is pressed by the large plunger and the small plunger to form an inner seal, and the second sealing flange is pressed by the cylinder body and the bushing to form an outer seal.

[0007] Furthermore, the first step surface is provided with a first annular groove, and the first annular groove is used to accommodate the first sealing flange.

[0008] Furthermore, a second annular groove is formed at one end of the bushing facing the bottom surface of the third groove, and the second annular groove is used to accommodate the second sealing flange.

[0009] Furthermore, the elastic sealing member is disc-shaped, with a penetrating circular hole formed in the middle thereof, and the circular hole is used for the small plunger to pass through.

[0010] Furthermore, a guide ring is embedded in the hole wall of the first through hole.

[0011] Furthermore, the cylinder body is also provided with a small leakage hole passing through its outer circumference; one end of the bushing is provided with a penetrating stepped through hole, and a second through hole and an annular groove are provided on the hole wall of the stepped through hole, the second through hole connects the stepped through hole and the annular groove, and the small leakage hole is connected to the annular groove.

[0012] Furthermore, the plunger pump further comprises a plunger sleeve arranged in the stepped through hole, and one end of the small plunger away from the large plunger is movably arranged in the plunger sleeve.

[0013] Furthermore, the plunger pump also includes a distribution valve assembly with one end connected to the cylinder body, the distribution valve assembly includes a distribution valve body, an end cover, a suction valve and an extrusion valve, the distribution valve body is provided with a first distribution hole and a second distribution hole penetrating therethrough, the suction valve and the extrusion valve are respectively arranged in the first distribution hole and the second distribution hole; the first distribution hole and the second distribution hole are respectively connected to the plunger sleeve; the inner wall of the plunger sleeve, the end surface of the small plunger accommodated in the plunger sleeve and the end surface of the distribution valve body form a distribution cavity; the end cover is connected to the end surface of the distribution valve body away from the cylinder body, and is provided with a water inlet hole, the water inlet hole is connected to the distribution cavity through the first distribution valve hole; the leakage hole is connected to the water inlet hole.

[0014] In general, the above technical solution conceived by the present invention is compared with the prior art, and the leakage-free oil-water separation plunger pump provided by the present invention has the following beneficial effects:

[0015] 1. The first stepped surface and the large plunger press the middle part of the elastic seal to form an inner seal, and the bushing and the bottom surface of the third groove press the outer edge of the elastic seal to form an outer seal. The inner seal and the outer seal are used together to isolate the working medium and the lubricating medium located on opposite sides of the elastic seal. In this way, the static seal formed by the elastic seal replaces the dynamic seal to achieve the purpose of complete isolation of lubricating oil and water. No dynamic seal is required, which reduces the way of heat generation, can prevent oil and water from seeping into each other during the movement of the plunger, and further prevent the lubrication performance of the lubricating medium from being reduced due to the mixing of impurities.

[0016] 2. The plunger pump has good adaptability to plunger eccentricity. Unlike the existing dynamic sealing structure, when the plunger tilts due to lateral force, it will not affect the elastic seal.

[0017] 3. In addition to accommodating the elastic seal, the stepped through hole can also serve as a cooling chamber. It is connected to the water inlet of the pump, which can quickly take away the heat generated by the deformation of the elastic seal and the friction between the small plunger and the plunger sleeve, thereby reducing the thermal deformation of the small plunger and the plunger sleeve.

[0018] 4. A first annular groove and a second annular groove are respectively provided to accommodate the first sealing flange and the second sealing flange, and the compression between the first step surface and the large plunger, and the compression between the bushing and the bottom surface of the third groove are ensured to ensure the stability of the inner and outer seals and better sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a cross-sectional view of a leak-free oil-water separation plunger pump provided by the present invention when it is located at the liquid suction limit position;

[0020] Figure 2 yes Figure 1 A cross-sectional view of the leak-free oil-water separation plunger pump at the discharge limit position;

[0021] Figure 3 yes Figure 1 Schematic diagram of the elastic seal in;

[0022] Figure 4 yes Figure 1 Assembly diagram of the large plunger and the small plunger;

[0023] Figure 5 yes Figure 1 Assembly diagram of cylinder block and bushing.

[0024] In all the drawings, the same reference numerals are used to represent the same elements or structures, where: 1-elastic seal, 2-large plunger, 3-slipper, 4-small plunger, 5-cylinder body, 6-bushing, 7-plunger sleeve, 8-distribution valve assembly, 8.1-distribution valve body, 8.2-end cover, 8.3-intake valve, 8.4-extrusion valve, 9.1-first sealing ring, 9.2-second sealing ring, 9.3-third sealing ring, 9.4-fourth sealing ring, 9.5-guide ring. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0026] The present invention provides a leak-free oil-water separation plunger pump, which uses an elastic seal to achieve the purpose of completely isolating lubricating oil and water during the movement of the plunger, further improving the service life of the pump.

[0027] See also Figure 1 and Figure 2 The plunger pump includes an elastic seal 1, a large plunger 2, a small plunger 4, a slipper 3, a cylinder body 5, a bushing 6, a plunger sleeve 7 and a distribution valve assembly 8. One end of the bushing 6 is arranged in the end of the cylinder body 5 adjacent to the distribution valve assembly 8, and the other end is connected to the distribution valve assembly 8. The plunger sleeve 7 is arranged in the end of the bushing 6 adjacent to the distribution valve assembly 8, and it abuts against the distribution valve assembly 8. One end of the large plunger 2 is connected to the slipper 3, and the other end is connected to one end of the small plunger 4. The other end of the small plunger 4 is movably arranged in the plunger sleeve 7. The small plunger 4 passes through the elastic seal 1 and is connected to the large plunger 2 through a thread. The edge of the elastic seal 1 is pressed against the end surface of the bushing 6 by the cylinder body 5 to form an outer seal, and the middle part of the elastic seal 1 is pressed by the large plunger 2 and the small plunger 4 to form an inner seal. The outer seal and the inner seal are both static seals, and isolate the working medium and lubricating medium located on both sides of the elastic seal 1.

[0028] See also Figure 3The elastic seal 1 is disc-shaped, with a circular hole extending through its center for the passage of the small plunger 4. Two concentrically arranged annular sealing flanges, a first sealing flange and a second sealing flange, are also formed on the same side of the elastic seal 1. The diameter of the first sealing flange is smaller than that of the second sealing flange, and the diameter of the circular hole is smaller than that of the first sealing flange. The first sealing flange is compressed by the large plunger 2 and the small plunger 4 to form an inner seal, while the second sealing flange is compressed by the cylinder body 5 and the bushing 6 to form an outer seal. In this embodiment, the central axes of the first sealing flange, the second sealing flange, and the circular hole coincide.

[0029] See also Figure 4 The large plunger 2 is cylindrical, and a first groove and a second groove are respectively provided at its two opposite ends. The first groove is used to accommodate the small plunger 4. Specifically, an internal thread is formed on the groove wall of the first groove, and the first groove is threadedly connected to the small plunger 4 through the internal thread. The large plunger 2 is also provided with a pin hole, and a connecting pin cooperates with the pin hole to achieve the connection between the sliding shoe 3 and the large plunger 2. The sliding shoe 3 is partially accommodated in the second groove. In this embodiment, the central axis of the first groove, the central axis of the second groove and the central axis of the large plunger 2 coincide with the central axis of the large plunger 2, and the central axis of the pin hole is perpendicular to the central axis of the large plunger 2.

[0030] The small plunger 4 is a stepped cylindrical body comprising a first end and a second end connected to form a first stepped surface. The diameter of the first end is smaller than the diameter of the second end. The first stepped surface defines a first annular groove for accommodating the first sealing flange. The outer circumferential surface of the first end is formed with an external thread, which passes through the circular hole of the elastic seal 1 and forms a threaded connection with the first groove.

[0031] See also Figure 5 The cylinder body 5 is a cylindrical body with a third groove formed at one end. The bottom surface of the third groove is provided with a first through hole, which is used to accommodate the large plunger 2. The guide ring 9.5 is provided between the first through hole and the large plunger 2. The cylinder body 5 also has a leakage hole extending through its outer circumference, which is connected to the third groove. The first stepped surface and the large plunger 2 press the middle part of the elastic seal 1 to form an inner seal, and the bushing 6 and the bottom surface of the third groove press the outer edge of the elastic seal 1 to form an outer seal.

[0032] The bushing 6 is arranged in the third groove and abuts against the bottom surface of the third groove. The bushing 6 is a cylinder, and one end of the bushing is provided with a stepped through hole, forming a second stepped surface. The two ends of the bushing 6 are respectively the third end and the fourth end, and the stepped through hole includes a large hole and a small hole that are connected and coaxial, the large hole passes through the fourth end, and the small hole passes through the third end. The third end is provided with a second annular groove, and the second annular groove is used to accommodate the second sealing flange. The bushing 6 also has a second through hole and an annular groove, and the second through hole is connected to the small hole and the annular groove, and the leakage hole is connected to the annular groove.

[0033] The plunger sleeve 7 is cylindrical and has a third through-hole extending therethrough. The third through-hole is configured to receive the small plunger 4. The plunger sleeve 7 rests against the second stepped surface. The outer circumference of the small plunger 4, the wall of the small hole, the bottom surface of the plunger sleeve 7, and the bottom surface of the third groove form a receiving cavity for receiving the elastic seal 1.

[0034] The central axis of the cylinder body 5, the central axis of the third groove, and the central axis of the first through hole coincide; the central axis of the bushing 6 coincides with the central axis of the stepped through hole, and the central axis of the plunger sleeve 7 coincides with the central axis of the third through hole. The edges of the large plunger 2, the small plunger 4, the cylinder body 5, and the bushing 6 that contact the elastic seal 1 are all rounded to prevent damage to the elastic seal 1 during operation of the plunger pump.

[0035] The distribution valve assembly 8 includes a distribution valve body 8.1, an end cover 8.2, an intake valve 8.3, and an extrusion valve 8.4. The distribution valve body is provided with a first distribution hole and a second distribution hole extending therethrough. The intake valve 8.3 and the extrusion valve 8.4 are respectively arranged in the first distribution hole and the second distribution hole. The first distribution hole and the second distribution hole are respectively connected to the third through hole. The distribution valve body 8.1 is connected to the cylinder body 5 by bolts. The inner wall of the third through hole, the end face of the second end of the small plunger 4, and the end face of the distribution valve body 8.1 form a distribution cavity. The end cover 8.2 is connected to the end face of the distribution valve body 8.1 away from the cylinder body 5 and is provided with a water inlet. The water inlet is connected to the distribution cavity through the first distribution valve hole. The leakage hole is connected to the water inlet.

[0036] A first sealing ring 9.1 and a second sealing ring 9.2 are provided between the end cover 8.2 and the distribution valve body 8.1, a third sealing ring 9.3 is provided between the plunger sleeve 7 and the distribution valve body 8.1, and a fourth sealing ring 9.4 is provided between the plunger sleeve 7 and the cylinder body 5.

[0037] When the slipper 3 drives the large plunger 2 and the small plunger 4 to move leftward, the volume of the distribution chamber decreases and the pressure of the working medium in the distribution chamber gradually increases. When the pressure is greater than the opening pressure of the extrusion valve 8.4, the extrusion valve 8.4 opens and the plunger pump discharges liquid. During this process, the suction valve 8.3 remains in a closed state; when the slipper 3 drives the large plunger 2 and the small plunger 4 to move rightward, the volume of the distribution chamber increases, negative pressure is formed in the chamber, the suction valve 8.3 opens, and the plunger pump draws liquid. During this process, the extrusion valve 8.4 remains in a closed state.

[0038] The medium inside the cavities connected to the left side of the elastic seal 1 is the working medium, while the medium inside the cavities connected to the right side is the lubricating medium. During the plunger pump's suction and discharge processes, the elastic seal continuously stretches and compresses with the movement of the large plunger 2 and the small plunger 4. The resulting inner and outer seals are both static seals, completely isolating the working medium from the lubricating medium.

[0039] As the plunger pump moves, the working medium leaking into the receiving chamber can return to the water inlet of the pump through the second through-hole, the annular groove, and the leakage hole in sequence, removing the deformation of the elastic seal and the heat generated by the friction between the small plunger 4 and the plunger sleeve 7. The limiting effect can be achieved by limiting the travel range of the sliding shoe 3.

[0040] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A leak-free oil-water separation plunger pump, characterized by: The plunger pump includes a cylinder body, a bushing, a large plunger, a small plunger and an elastic seal; a third groove is provided at one end of the cylinder body, a first through hole is provided on the bottom surface of the third groove, and the first through hole is used to accommodate the large plunger; one end of the bushing is arranged in the third groove; the small plunger is stepped and forms a first step surface; one end of the small plunger is located in the bushing, and the other end passes through the elastic seal and is connected to the end of the large plunger located in the cylinder body; the first step surface and the large plunger press the middle part of the elastic seal to form an inner seal, and the bushing and the bottom surface of the third groove press the outer edge of the elastic seal to form an outer seal, and the inner seal and the outer seal are used together to isolate the working medium and the lubricating medium respectively located on the opposite sides of the elastic seal.

2. The leak-free oil-water separation plunger pump according to claim 1, characterized in that: Two concentrically arranged annular sealing flanges are formed on the same side of the elastic seal, namely the first sealing flange and the second sealing flange; the first sealing flange is pressed by the large plunger and the small plunger to form an inner seal, and the second sealing flange is pressed by the cylinder body and the bushing to form an outer seal.

3. The leak-free oil-water separation plunger pump according to claim 2, characterized in that: A first annular groove is formed on the first step surface, and the first annular groove is used to accommodate the first sealing flange.

4. The leak-free oil-water separation plunger pump according to claim 2, characterized in that: A second annular groove is formed at one end of the bushing facing the bottom surface of the third groove, and the second annular groove is used to accommodate the second sealing flange.

5. The leak-free oil-water separation plunger pump according to any one of claims 1 to 4, characterized in that: The elastic sealing member is in the shape of a disk, with a penetrating circular hole provided in the middle thereof, and the circular hole is used for the small plunger to pass through.

6. The leak-free oil-water separation plunger pump according to any one of claims 1 to 4, characterized in that: A guide ring is embedded in the hole wall of the first through hole.

7. The leak-free oil-water separation plunger pump according to any one of claims 1 to 4, characterized in that: The cylinder body is also provided with a small leakage hole running through its outer circumference; one end of the bushing is provided with a penetrating stepped through hole, a second through hole and an annular groove are provided on the hole wall of the stepped through hole, the second through hole connects the stepped through hole and the annular groove, and the small leakage hole is connected to the annular groove.

8. The leak-free oil-water separation plunger pump according to claim 7, characterized in that: The plunger pump further comprises a plunger sleeve arranged in the stepped through hole, and one end of the small plunger away from the large plunger is movably arranged in the plunger sleeve.

9. The leak-free oil-water separation plunger pump according to claim 8, characterized in that: The plunger pump also includes a distribution valve assembly with one end connected to the cylinder body, and the distribution valve assembly includes a distribution valve body, an end cover, a suction valve and an extrusion valve. The distribution valve body is provided with a first distribution hole and a second distribution hole penetrating therethrough, and the suction valve and the extrusion valve are respectively arranged in the first distribution hole and the second distribution hole; the first distribution hole and the second distribution hole are respectively connected to the plunger sleeve; the inner wall of the plunger sleeve, the end surface of the small plunger accommodated in the plunger sleeve and the end surface of the distribution valve body form a distribution cavity; the end cover is connected to the end surface of the distribution valve body away from the cylinder body, and is provided with a water inlet hole, which is connected to the distribution cavity through the first distribution valve hole; the leakage hole is connected to the water inlet hole.

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