CN-121993394-A - End sealing and cooling structure for plunger

Abstract

The invention provides an end sealing cooling structure for a plunger, which comprises a sealing sleeve and the plunger penetrating through a core part of the sealing sleeve, wherein a thread sleeve, a water jacket, a three-stage sealing structure and a guide sleeve are sequentially arranged between the plunger and the sealing sleeve, an annular cooling flow passage is formed between the water jacket and the plunger and between the water jacket and the sealing sleeve respectively, the annular cooling flow passage is communicated with a cooling medium inlet and a cooling medium outlet on the sealing sleeve, a pressure detection device is arranged on a quick-change connector at the cooling medium outlet, the three-stage sealing structure comprises three UN sealing rings and three support rings, the UN sealing rings and the support rings are arranged at intervals, an annular groove is formed in the UN sealing ring, and an annular bulge is formed in the support ring and is spliced with the annular groove. The problem that the existing sealing structure is easy to fail in a high-temperature high-pressure environment and cannot discover sealing failure in time is solved.

Inventors

• LI MENGTIAN
• Yuan Zhidai
• Luo Shuaixun
• DONG CHAOHUI
• YANG LEI
• JIA LILONG

Assignees

• 山东大学

Dates

Publication Date

20260508

Application Date

20260331

Claims (10)

1. 1. The end sealing and cooling structure for the plunger is characterized by comprising a sealing sleeve and a plunger penetrating through a core part of the sealing sleeve, wherein a microstructure is arranged on the side wall of the plunger, a thread sleeve, a water jacket, a three-stage sealing structure and a guide sleeve are sequentially arranged between the plunger and the sealing sleeve, three-stage stepped holes are formed in the sealing sleeve, the three-stage stepped holes are respectively a first-stage hole, a second-stage hole and a third-stage hole with diameters being sequentially reduced, the thread sleeve is arranged in the first-stage hole through threads, the water jacket, the three-stage sealing structure and the guide sleeve are arranged in the second-stage hole, the plunger is in clearance fit with the third-stage hole, an annular cooling flow passage is formed between the water jacket and the plunger respectively, the annular cooling flow passage is communicated with a cooling medium inlet and a cooling medium outlet on the sealing sleeve, and a pressure detection device is arranged on a quick-change joint at the cooling medium outlet; The three-stage sealing structure comprises three UN sealing rings and three supporting rings, wherein the UN sealing rings and the supporting rings are arranged at intervals, each UN sealing ring corresponds to one supporting ring, an annular groove is formed in each UN sealing ring, annular protrusions are arranged on the supporting rings, the annular protrusions are inserted into the annular grooves, the UN sealing rings are unfolded, and the UN sealing rings are respectively pressed with the plunger and the sealing sleeve to form sealing.
2. 2. An end seal cooling structure for a plunger according to claim 1, wherein said annular groove is provided on one side of said UN seal ring, said annular projection is provided on one side of said support ring, the cross-sectional shapes of said annular groove and said annular projection are wedge-shaped, trapezoid-shaped, and the cross-sectional size of said annular groove is larger than the cross-sectional size of said annular projection.
3. 3. An end seal cooling structure for a plunger according to claim 2, wherein said pipe joints are a cooling medium inlet joint and a cooling medium outlet joint, respectively, and an included angle between axes of said cooling medium inlet joint and said cooling medium outlet joint is 60 ° or less.
4. 4. An end seal cooling structure for a plunger according to claim 1, wherein a first O-ring and a second O-ring are provided on an end face of one end of a third stage bore of the sealing sleeve, and a curvature of the first O-ring is larger than a curvature of the second O-ring.
5. 5. An end seal cooling structure for a plunger as set forth in claim 4 wherein said water jacket is provided with a U-shaped seal ring on a side thereof adjacent to said plunger, a recess of said U-shaped seal ring being directed in a cooling flow passage direction.
6. 6. An end seal cooling structure for a plunger according to claim 5, wherein a third O-ring is provided on a side of the water jacket adjacent to the seal sleeve, and both the U-ring and the third O-ring are disposed on an end of the water jacket adjacent to the screw sleeve.
7. 7. An end seal cooling structure for a plunger as set forth in claim 1 wherein said sealing sleeve is carbon structural steel and is subjected to a tempering heat treatment.
8. 8. An end seal cooling structure for a plunger as set forth in claim 1 wherein said cooling medium inlet and cooling medium outlet are each provided with a quick change connector having a combination washer mounted thereon.
9. 9. An end seal cooling structure for a plunger as set forth in claim 1 wherein said pressure sensing means is a pressure sensor.
10. 10. An end seal cooling structure for a plunger according to claim 1, wherein said support ring is made of an engineering plastic material having self-lubricating properties and having a hardness higher than that of the UN seal ring so that the UN seal ring can effectively fill the radial gap between the plunger and the seal sleeve.

Description

End sealing and cooling structure for plunger Technical Field The invention belongs to the technical field of plunger pumps, and particularly relates to an end sealing and cooling structure for a plunger. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. The grouting pump, the high-pressure plunger pump, the fuel injection system and the hydraulic power device realize the suction, compression and discharge of fluid through the periodical change of the volume of the working cavity, so that the plunger can perform high-frequency reciprocating motion in the closed cavity. In this process, the plunger end is not only subjected to periodically alternating high pressure impacts, but also needs to maintain high-speed relative movement with the sealing element or the inner wall of the cylinder sleeve during each reciprocating stroke. This mechanical and kinematic coupling makes the end seal subject to three major core challenges, namely the permanent reliability of the dynamic seal, the resistance to extrusion under extreme pressure, and the long life requirement at low frictional wear. In addition, the sealing structure cannot monitor whether leakage exists in real time, leakage of high-temperature and high-pressure medium or early failure of the sealing structure is difficult to discover in time, and great potential safety hazard exists. Disclosure of Invention Aiming at the problems, the invention provides an end sealing and cooling structure for a plunger, which solves the problems that the existing sealing structure is easy to fail in a high-temperature and high-pressure environment and can not find out the sealing failure in time. In order to achieve the above object, the present invention is realized by the following technical scheme: The invention provides an end sealing and cooling structure for a plunger, which comprises a sealing sleeve and the plunger penetrating through a core part of the sealing sleeve, wherein a microstructure is arranged on the side wall of the plunger, a thread bush, a water jacket, a three-stage sealing structure and a guide sleeve are sequentially arranged between the plunger and the sealing sleeve, three-stage stepped holes are formed in the sealing sleeve, the three-stage stepped holes are respectively a first-stage hole, a second-stage hole and a third-stage hole with sequentially reduced diameters, the thread bush is arranged in the first-stage hole through threads, the water jacket, the three-stage sealing structure and the guide sleeve are arranged in the second-stage hole, the plunger is in clearance fit with the third-stage hole, an annular cooling flow passage is formed between the water jacket and the plunger respectively, the annular cooling flow passage is communicated with a cooling medium inlet and a cooling medium outlet on the sealing sleeve, and a pressure detection device is arranged on a quick-change connector at the cooling medium outlet; The three-stage sealing structure comprises three UN sealing rings and three supporting rings, wherein the UN sealing rings and the supporting rings are arranged at intervals, each UN sealing ring corresponds to one supporting ring, an annular groove is formed in each UN sealing ring, annular protrusions are arranged on the supporting rings, the annular protrusions are inserted into the annular grooves, the UN sealing rings are unfolded, and the UN sealing rings are respectively pressed with the plunger and the sealing sleeve to form sealing. As a further implementation manner, the annular groove is arranged on one side of the UN sealing ring, the annular protrusion is arranged on one side of the supporting ring, the cross section shapes of the annular groove and the annular protrusion are wedge-shaped and trapezoid, and the cross section size of the annular groove is larger than that of the annular protrusion. As a further implementation mode, the pipeline joints are a cooling medium inlet joint and a cooling medium outlet joint respectively, and an included angle between the axes of the cooling medium inlet joint and the cooling medium outlet joint is less than or equal to 60 degrees. As a further implementation mode, a first O-shaped sealing ring and a second O-shaped sealing ring are arranged on the end face of one end of the third-stage hole of the sealing sleeve, and the curvature of the first O-shaped sealing ring is larger than that of the second O-shaped sealing ring. As a further implementation mode, a U-shaped sealing ring is arranged on one side, close to the plunger, of the water jacket, and a notch of the U-shaped sealing ring faces the direction of the cooling flow passage. As a further implementation mode, a third O-shaped sealing ring is arranged on one side, close to the sealing sleeve, of the water jacket, and the U-shaped sealing ring and the third O-shaped sealing ring are both arranged at one end