A leakage-free oil-water separation type plunger pump

Abstract

This invention belongs to the technical field of plunger pumps and discloses a leak-free oil-water separation plunger pump, including a cylinder, a bushing, a large plunger, a small plunger, and an elastic seal. A third groove is formed at one end of the cylinder, and a first through hole is formed on the bottom surface of the third groove to accommodate the large plunger. One end of the bushing is disposed within the third groove. The small plunger is stepped, forming a first stepped surface. One end of the small plunger is located inside the bushing, and the other end passes through the elastic seal and connects to the end of the large plunger located within the cylinder. The first stepped surface and the large plunger press the middle of the elastic seal to form an inner seal, while 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 and outer seals work together to isolate the working medium and the lubrication medium located on opposite sides of the elastic seal, preventing oil-water cross-contamination.

Description

Technical Field

[0001] This invention belongs to the technical field of plunger pumps, and more specifically, relates to a leak-free oil-water separation plunger pump. Background Technology

[0002] Traditional hydraulic systems use mineral oil as the working medium. Although the technology is mature, it suffers from problems such as environmental pollution, flammability, and high maintenance costs. With increasingly stringent environmental regulations and growing demand for green manufacturing, water-hydraulic technology has become a highly promising alternative due to its non-toxic, non-flammable medium (pure water or seawater) and low cost.

[0003] As the core power component of a hydraulic system, the pump's performance has a decisive impact on the development of water hydraulic technology. Due to water's low viscosity and poor lubrication performance, most pumps used in water hydraulic systems employ an oil-water separation structure to improve the lubrication environment of the friction pairs and enhance the pump's anti-contamination capability. This means the lubricating medium is oil, and the working medium is water. However, this introduces the problem of water and oil sealing isolation. Existing sealing structures are dynamic seals, which inevitably lead to oil-water interleaving. This interleaving intensifies when the plunger tilts due to lateral forces and the seals wear. As the pump operates, the viscosity of the lubricating medium in the drive chamber decreases, causing the friction pairs to wear out quickly and eventually fail, resulting in a reduced pump lifespan. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a leak-free oil-water separation plunger pump, which aims to solve the problem of oil-water mutual seepage that easily occurs in oil-water separation plunger pumps.

[0005] To achieve the above objectives, according to one aspect of the present invention, a leak-free oil-water separating plunger pump is provided. The plunger pump includes a cylinder, a bushing, a large plunger, a small plunger, and an elastic seal. A third groove is formed at one end of the cylinder, and a first through hole is formed on the bottom surface of the third groove for receiving the large plunger. One end of the bushing is disposed within the third groove. The small plunger is stepped, forming a first stepped surface. One end of the small plunger is located within the bushing, and the other end passes through the elastic seal and connects to the end of the large plunger located within the cylinder. The first stepped surface and the large plunger press the middle portion 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 and outer seals together isolate the working medium and the lubrication medium located on opposite sides of the elastic seal.

[0006] Furthermore, two concentric 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 stepped 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 provided 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 seal is disc-shaped with a through circular hole in its center, through which the small plunger passes.

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

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

[0012] Furthermore, the plunger pump also includes a plunger sleeve disposed within the stepped through hole, with the end of the small plunger away from the large plunger movably disposed within the plunger sleeve.

[0013] Furthermore, the plunger pump also includes a distribution valve assembly connected to the cylinder block at one end. The distribution valve assembly includes a distribution valve body, an end cap, a suction valve, and a discharge valve. The distribution valve body has a through first distribution hole and a second distribution hole. The suction valve and the discharge valve are respectively disposed 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 face of the small plunger housed in the plunger sleeve, and the end face of the distribution valve body form a distribution cavity. The end cap is connected to the end face of the distribution valve body away from the cylinder block and has 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 summary, compared with the prior art, the leak-free oil-water separating plunger pump provided by this invention has the following advantages:

[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 work together to isolate the working medium and the lubrication 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 completely isolating the lubricating oil and water. There is no need for a dynamic seal, which reduces the path of heat generation and prevents oil and water from seeping into each other during the movement of the plunger. It also prevents the lubrication performance from being reduced due to impurities mixed in with the lubricating medium.

[0016] 2. The plunger pump has good plunger eccentricity adaptability, unlike the existing dynamic seal 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 and can quickly remove 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. With the compression of the first stepped surface and the large plunger, and the compression between the bushing and the bottom surface of the third groove, the stability of the inner layer seal and the outer layer seal and the good sealing performance are ensured. Attached Figure Description

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

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

[0021] Figure 3 yes Figure 1 A schematic diagram of the elastic seal in the image;

[0022] Figure 4 yes Figure 1 A schematic diagram of the assembly of the large and small plungers;

[0023] Figure 5 yes Figure 1 A schematic diagram of the assembly of the cylinder block and bushing.

[0024] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-elastic seal, 2-large plunger, 3-slipper, 4-small plunger, 5-cylinder body, 6-shield, 7-plunger sleeve, 8-distribution valve assembly, 8.1-distribution valve body, 8.2-end cap, 8.3-suction valve, 8.4-discharge 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 Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be 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 illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0026] This invention provides a leak-free oil-water separation plunger pump. The plunger pump uses an elastic seal to completely isolate lubricating oil and water during the plunger's movement, thereby further improving the pump's lifespan.

[0027] Please see 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 5, a bushing 6, a plunger sleeve 7, and a flow distribution valve assembly 8. One end of the bushing 6 is disposed within the cylinder 5 adjacent to the flow distribution valve assembly 8, and the other end is connected to the flow distribution valve assembly 8. The plunger sleeve 7 is disposed within the bushing 6 adjacent to the flow distribution valve assembly 8 and abuts against the flow 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 disposed within the plunger sleeve 7, and the small plunger 4 passes through the elastic seal 1 and is threadedly connected to the large plunger 2. The edge of the elastic seal 1 is pressed against the end face of the bushing 6 by the cylinder 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. Both the outer seal and the inner seal are static seals, and they isolate the working medium and the lubricating medium located on both sides of the elastic seal 1.

[0028] Please see Figure 3The elastic seal 1 is disc-shaped with a through circular hole at its center for the small plunger 4 to pass through. Two concentric annular sealing flanges, a first sealing flange and a second sealing flange, are 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 pressed together by the large plunger 2 and the small plunger 4 to form an inner seal, and the second sealing flange is pressed together 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] Please see Figure 4 The large plunger 2 is cylindrical, with a first groove and a second groove formed at its 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 also has a pin hole, and a connecting pin engages with the pin hole to connect the slipper 3 to the large plunger 2. The slipper 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, 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 cylinder, comprising a first end and a second end connected together, forming a first stepped surface. The diameter of the first end is smaller than the diameter of the second end. The first stepped surface has a first annular groove for accommodating the first sealing flange. The outer circumferential surface of the first end has an external thread, which passes through the circular hole of the elastic seal 1 and forms a threaded connection with the first groove.

[0031] Please see Figure 5 The cylinder body 5 is cylindrical, with a third groove at one end. A first through hole is formed on the bottom surface of the third groove, which accommodates the large plunger 2. A guide ring 9.5 is positioned between the first through hole and the large plunger 2. The cylinder body 5 also has a small leakage hole penetrating its outer circumference, which communicates with the third groove. The first stepped surface and the large plunger 2 press the middle of the elastic seal 1 to form an inner seal, while 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 disposed within the third groove and abuts against the bottom surface of the third groove. The bushing 6 is cylindrical, with a through-hole at one end forming a second stepped surface. The two ends of the bushing 6 are the third end and the fourth end, respectively. The stepped through-hole includes a large hole and a small hole that are connected and coaxial. The large hole penetrates the fourth end, and the small hole penetrates the third end. The third end has a second annular groove for receiving the second sealing flange. The bushing 6 also has a second through-hole and an annular groove. The second through-hole connects the small hole and the annular groove, and the leakage small hole is connected to the annular groove.

[0033] The plunger sleeve 7 is cylindrical and has a through third hole for receiving the small plunger 4. The plunger sleeve 7 abuts against the second stepped surface. The outer peripheral surface 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 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 5, and the bushing 6 that contact the elastic seal 1 are all rounded to prevent damage to the elastic seal 1 during the operation of the plunger pump.

[0035] The distribution valve assembly 8 includes a distribution valve body 8.1, an end cap 8.2, an intake valve 8.3, and a discharge valve 8.4. The distribution valve body has a through first distribution hole and a second distribution hole. The intake valve 8.3 and the discharge valve 8.4 are respectively disposed 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 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 cap 8.2 is connected to the end face of the distribution valve body 8.1 away from the cylinder 5, and has 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.

[0036] A first sealing ring 9.1 and a second sealing ring 9.2 are provided between the end cap 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 to the left, 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 discharge valve 8.4, the discharge valve 8.4 opens, and the plunger pump discharges liquid. During this process, the suction valve 8.3 remains closed. When the slipper 3 drives the large plunger 2 and the small plunger 4 to move to the right, the volume of the distribution chamber increases, and a negative pressure is formed in the chamber. The suction valve 8.3 opens, and the plunger pump draws in liquid. During this process, the discharge valve 8.4 remains closed.

[0038] The media inside the cavities connected to the left side of the elastic seal 1 are the working media, and the media inside the cavities connected to the right side are the lubricating media. During the suction and discharge process of the plunger pump, the elastic seal is continuously stretched and compressed with the movement of the large plunger 2 and the small plunger 4, forming both inner and outer seals that are static seals, which can achieve the effect of completely isolating the working media from the lubricating media.

[0039] As the plunger pump moves, the working medium leaking into the receiving cavity can sequentially return to the pump's inlet through the second through hole, the annular groove, and the leakage hole, carrying away the heat generated by the deformation of the elastic seal and the friction between the small plunger 4 and the plunger sleeve 7. The limiting effect can be achieved by restricting the stroke range of the slipper 3.

[0040] Those skilled in the art will readily understand 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 within the scope of protection of the present invention.

Claims

1. A leak-free oil-water separating plunger pump, characterized in that: The plunger pump includes a cylinder, a bushing, a large plunger, a small plunger, and an elastic seal. One end of the cylinder has a third groove, and the bottom surface of the third groove has a through-hole for receiving the large plunger. One end of the bushing is disposed within the third groove. The small plunger is stepped, forming a first stepped surface. One end of the small plunger is located within the bushing, and the other end passes through the elastic seal and connects to the end of the large plunger located within the cylinder. The first stepped surface and the large plunger press the middle 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 and outer seals together isolate the working medium and lubricating medium located on opposite sides of the elastic seal. Two concentric 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. The cylinder block also has a small leakage hole penetrating its outer circumference; one end of the bushing has a through stepped through hole, and the wall of the stepped through hole has a second through hole and an annular groove, the second through hole connecting the stepped through hole and the annular groove, and the leakage hole communicating with the annular groove; the plunger pump also includes a plunger sleeve disposed in the stepped through hole, and the end of the small plunger away from the large plunger is movably disposed in the plunger sleeve; the plunger pump also includes a flow distribution valve assembly connected to the cylinder block at one end, the flow distribution valve assembly including a flow distribution valve body, an end cap, an intake valve, and an outlet valve. The valve has a first distribution hole and a second distribution hole through it. The suction valve and the discharge valve are respectively disposed 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 face of the small plunger housed in the plunger sleeve, and the end face of the distribution valve body form a distribution cavity. The end cap is connected to the end face of the distribution valve body away from the cylinder body and has a water inlet hole. The water inlet hole is connected to the distribution cavity through the first distribution hole. The leakage hole is connected to the water inlet hole.

2. The leak-free oil-water separating plunger pump as described in claim 1, characterized in that: The first stepped surface has a first annular groove, which is used to accommodate the first sealing flange.

3. The leak-free oil-water separating plunger pump as described in claim 1, characterized in that: The bushing has a second annular groove at one end facing the bottom of the third groove, and the second annular groove is used to accommodate the second sealing flange.

4. The leak-free oil-water separating plunger pump as described in any one of claims 1-3, characterized in that: The elastic seal is disc-shaped with a through circular hole in its center, through which the small plunger passes.

5. The leak-free oil-water separating plunger pump as described in any one of claims 1-3, characterized in that: A guide ring is embedded in the wall of the first through hole.

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