End face sealing structure of high-pressure oil pump

Abstract

The invention provides a high-pressure oil pump end face sealing structure. The sealing structure comprises a sealing groove, a sealing piece and a sealing side plate. The sealing groove is an annular groove. The sealing groove is formed in the end face of the oil pump cavity. The whole section of the sealing groove is rectangular, and the sealing groove comprises a bottom, an outer straight edge, an inner straight edge and an opening part. And the height H1 of the outer straight edge is higher than the height H1'of the inner straight edge. And the width of the opening part is W1. The sealing piece is an annular sealing ring. The section of the sealing piece is in an L shape, and the sealing piece is in a step shape with the wide upper portion and the narrow lower portion in the axial direction. High-pressure oil is introduced to the bottom of the L-shaped sealing piece, follow-up sealing force is generated through the pressure of a system, and the dynamic self-adaption effect that the higher the pressure is, the tighter the sealing is is is achieved. The sealing reliability under the working conditions of high pressure and violent pressure pulsation is ensured, and a key guarantee is provided for achieving high volume efficiency.

Description

Technical Field

[0001] This invention relates to the field of high-pressure sealing technology, and in particular to a high-pressure oil pump end face sealing structure. Background Technology

[0002] As a core functional component of the electronic pump unit (MPU) in a fully active hydraulic suspension system, the bidirectional high-pressure oil pump directly determines the dynamic response, energy efficiency, and reliability of the suspension system. To meet the high-performance requirements of active suspension, such pumps typically need to operate under extremely high pressure and possess extremely fast dynamic response speeds, while also imposing extremely stringent standards on their volumetric efficiency, energy consumption, and service life. Against this backdrop, the end-face sealing technology inside the pump becomes crucial to ensuring its overall performance, and its reliability is paramount.

[0003] In the field of high-pressure oil pumps, traditional end-face sealing solutions primarily rely on the elastic deformation of the sealing element itself to provide sealing pressure. An elastic sealing element with a specific compression ratio is pre-installed in the sealing groove, and the rebound force generated after compression continuously adheres to the sealing surface to achieve a sealing effect. However, with the significant increase in operating pressure and the intensification of pressure pulsation, this traditional sealing structure has gradually revealed the following inherent defects:

[0004] A. Insufficient dynamic sealing performance: Under severe pressure pulsations up to 20 MPa, the sealing pressure provided solely by the inherent elasticity of the seal is fixed and limited, making it difficult to dynamically adapt to the instantaneous peak values ​​of hydraulic pressure. This easily leads to the sealing interface being briefly pushed open under high-pressure impact, resulting in leakage and a decrease in volumetric efficiency, failing to meet the high efficiency requirement of over 96%. Simultaneously, high-frequency pressure impacts accelerate the fatigue aging of the sealing material, leading to elastic failure.

[0005] B. Poor resistance to extrusion and low reliability: Extremely high fluid pressure, especially the radial pressure component, can generate enormous shear forces on the seals. Traditional symmetrical seals are easily extruded from the sealing gap under high pressure, leading to twisting, localized tearing, or permanent deformation, causing rapid failure of the sealing structure and severely impacting the reliability of the oil pump.

[0006] C. High frictional resistance, poor energy efficiency and wear resistance: To ensure no failure under peak pressure, traditional designs often rely on increasing the compression of the seal to barely maintain a seal. This directly leads to a significant increase in the frictional torque of the seal on the moving parts. On the one hand, this increases the driving torque of the oil pump, resulting in increased energy consumption, which does not meet the requirements for low energy consumption; on the other hand, excessive friction will drastically accelerate the wear of the seal and its mating moving parts, reducing the service life and wear resistance reliability of the oil pump.

[0007] Therefore, developing a high-pressure oil pump end face sealing structure has become an inevitable requirement to solve the technical bottleneck of high-performance bidirectional high-pressure oil pumps. Summary of the Invention

[0008] The purpose of this invention is to provide a high-pressure oil pump end face sealing structure to solve the problems existing in the prior art.

[0009] The technical solution adopted to achieve the purpose of this invention is as follows: a high-pressure oil pump end face sealing structure, including a sealing groove, a sealing element and a sealing side plate.

[0010] The sealing groove is an annular groove. It is located on the end face of the oil pump cavity. The cross-section of the sealing groove is generally rectangular, including a bottom, an outer straight side, an inner straight side, and an opening. The height H1 of the outer straight side is greater than the height H1′ of the inner straight side. The width of the opening is W1.

[0011] The sealing element is an annular sealing ring. The cross-section of the sealing element is L-shaped, exhibiting a stepped shape that is wider at the top and narrower at the bottom axially. The outline of the sealing element's cross-section includes an outer straight sealing lip, a stepped vertical edge, an inner straight gap lip, an upper horizontal edge, a lower horizontal edge, and a pressure-bearing edge. The outer straight sealing lip, the stepped vertical edge, and the inner straight gap lip are straight edges radially. The upper horizontal edge is the wider horizontal edge at the top of the L-shape. The lower horizontal edge is the horizontal edge at the bottom of the L-shape. The pressure-bearing edge is a stepped edge. The height H2 of the outer straight edge is greater than the height H2′ of the inner straight edge. The width W2 of the upper horizontal edge is greater than the width W2′ of the lower horizontal edge. The sealing element is assembled inside a sealing groove. The outer straight sealing lip fits tightly against the outer straight edge. The inner straight gap lip has a gap with the inner straight edge. The lower horizontal edge faces the bottom, and the upper horizontal edge faces the opening. The sealing side plate covers the opening.

[0012] The high-pressure oil C flows into the bottom of the sealing groove from the gap between the inner straight gap lip and the inner straight edge, acting on the vertical edge of the step, the inner straight gap lip, the lower horizontal edge, and the pressure-bearing edge, pushing the seal against the sealing side plate and the outer straight edge. The higher the pressure, the greater the sealing force, forming a dynamic self-tightening seal.

[0013] Furthermore, the difference between H1 and H1′ is 0.5–1.5 mm.

[0014] Furthermore, the difference between W1 and W2 is 0.2–0.4 mm.

[0015] Furthermore, H2′ = 2 / 3H2.

[0016] Furthermore, W2′ = 1 / 2W2.

[0017] The present invention also discloses a bidirectional high-pressure oil pump, including the aforementioned end-face sealing structure. The bidirectional high-pressure oil pump is used in automotive hydraulic suspension systems.

[0018] The technical effects of this invention are beyond doubt:

[0019] A. By introducing high-pressure oil to the bottom of the L-shaped seal, the system's own pressure generates a dynamic sealing force, achieving a dynamic adaptive effect where the higher the pressure, the tighter the seal. This ensures sealing reliability under high pressure and severe pressure pulsation conditions, providing a crucial guarantee for achieving high volumetric efficiency.

[0020] The unique cross-sectional arrangement of the BL type seal provides robust support, effectively resisting the radial impact of high-pressure oil and completely avoiding the risk of the seal being extruded, torn, or permanently deformed. This greatly improves the structural integrity and reliability of the seal under harsh operating conditions and significantly extends its service life.

[0021] C. System pressure becomes the primary source of sealing force, significantly reducing the elastic preload of the required seals. This directly leads to a significant reduction in frictional torque, which on the one hand reduces the driving power consumption of the oil pump, meeting low energy consumption requirements; on the other hand, it greatly reduces wear between the seals and moving parts, thereby improving the wear resistance, reliability, and long-term operational stability of the entire oil pump's moving parts. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the cross-section of the end face sealing structure of a high-pressure oil pump;

[0023] Figure 2 This is a schematic diagram of the cross-section of the sealing groove;

[0024] Figure 3 This is a schematic diagram of the cross-section of the seal;

[0025] Figure 4 This is a schematic diagram of the sealing end face of the sealing element;

[0026] Figure 5 This is a schematic diagram of the force applied to the straight edge of the seal.

[0027] In the diagram: sealing groove 1, bottom 11, outer straight edge 12, inner straight edge 13, opening 14, sealing element 2, outer straight sealing lip 21, inner straight gap lip 22, upper horizontal edge 23, lower horizontal edge 24 and pressure bearing edge 25, sealing side plate 3, high pressure oil C. Detailed Implementation

[0028] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0029] Example 1:

[0030] See Figures 1-5 This embodiment provides a high-pressure oil pump end face sealing structure, including a sealing groove 1, a sealing element 2, and a sealing side plate 3.

[0031] The sealing groove 1 is an annular groove. The sealing groove 1 is arranged on the end face of the oil pump cavity. The cross-section of the sealing groove 1 is generally rectangular, including a bottom 11, an outer straight side 12, an inner straight side 13, and an opening 14. The height H1 of the outer straight side 12 is higher than the height H1′ of the inner straight side 13. The width of the opening 14 is W1.

[0032] The sealing element 2 is an annular sealing ring. The cross-section of the sealing element 2 is L-shaped, exhibiting a stepped shape that is wider at the top and narrower at the bottom axially. The outline of the cross-section of the sealing element 2 includes an outer straight sealing lip 21, a stepped vertical edge, an inner straight gap lip 22, an upper horizontal edge 23, a lower horizontal edge 24, and a pressure-bearing edge 25. The outer straight sealing lip 21, the stepped vertical edge, and the inner straight gap lip 22 are straight edges in the radial direction. The upper horizontal edge 23 is the wider horizontal edge at the top of the L-shape. The lower horizontal edge 24 is the horizontal edge at the bottom of the L-shape. The pressure-bearing edge 25 is a stepped edge. The height H2 of the outer straight edge 21 is greater than the height H2′ of the inner straight edge 22. The width W2 of the upper horizontal edge 23 is greater than the width W2′ of the lower horizontal edge 24. The sealing element 2 is assembled inside the sealing groove 1. The outer straight sealing lip 21 is tightly fitted with the outer straight edge 12. A gap is left between the inner straight gap lip 22 and the inner straight edge 13. The lower horizontal edge 24 faces the bottom 11, and the upper horizontal edge 23 faces the opening 14. The sealing groove 1 provides assembly space for the seal 2 and also provides a pressure oil passage for the seal 2 to achieve pressure sealing.

[0033] The sealing side plate 3 covers the opening 14. The sealing side plate 3 seals the high-pressure oil inside the oil pump chamber, achieving the purpose of end face sealing.

[0034] The sealing structure is located in a high-pressure sealing environment. See also... Figure 3 and Figure 4 When the high-pressure oil pump is working, the high-pressure oil C flows into the bottom of the sealing groove from the gap between the inner straight gap lip 22 and the inner straight edge 13 at the oil outlet. This oil acts on the vertical edge of the step, the inner straight gap lip 22, the lower horizontal edge 24, and the pressure-bearing edge 25, pushing the seal 2 against the sealing side plate 3 and the outer straight edge 12. The higher the pressure, the greater the sealing force, forming a dynamic self-tightening seal. This structure, which does not rely on the elasticity of the seal itself for end-face sealing, can meet the requirements of high-pressure oil pumps with high operating pressure and large pulsating pressure.

[0035] Example 2:

[0036] The main content of this embodiment is the same as that of Embodiment 1, wherein the difference between H1 and H1′ is 0.5 to 1.5 mm. The difference between W1 and W2 is 0.2 to 0.4 mm. H2′ = 2 / 3H2. W2′ = 1 / 2W2.

[0037] Example 3:

[0038] This embodiment provides a bidirectional high-pressure oil pump, including an end-face sealing structure as described in Embodiment 1 or 2. The bidirectional high-pressure oil pump is used in automotive hydraulic suspension systems. In actual production, the high-pressure oil pump is a gear pump or a piston pump. The sealing side plate 3 can function as a distribution plate, or it can simply serve a partitioning function (like a baffle in an oil pump).

Claims

1. A high-pressure oil pump end face seal structure, the seal structure being used for a high-pressure oil pump oil outlet portion, characterized by: It comprises a sealing groove (1), a sealing member (2) and a sealing side plate (3). The sealing groove (1) is an annular groove; the sealing groove (1) is arranged at the end face of the oil pump cavity; the sealing groove (1) surrounds the oil outlet; the cross section of the sealing groove (1) is in the shape of a rectangle as a whole, comprising a bottom (11), an outer straight edge (12), an inner straight edge (13) and an outlet (14); the height H1 of the outer straight edge (12) is higher than the height H1' of the inner straight edge (13); the width of the outlet (14) is W1. The sealing member (2) is an annular sealing ring; the cross section of the sealing member (2) is in the shape of L, presenting a stepped shape with the upper part wider and the lower part narrower in the axial direction; the profile line of the cross section of the sealing member (2) comprises an outer straight sealing lip edge (21), a stepped vertical edge, an inner straight gap lip edge (22), an upper horizontal edge (23), a lower horizontal edge (24) and a pressure-bearing edge (25); the outer straight sealing lip edge (21), the stepped vertical edge and the inner straight gap lip edge (22) are straight edges in the radial direction; the upper horizontal edge (23) is a horizontal edge with the top part of the L shape wider; the lower horizontal edge (24) is a horizontal edge with the bottom part of the L shape; the pressure-bearing edge (25) is a stepped edge; the height H2 of the outer straight sealing lip edge (21) is greater than the height H2' of the inner straight gap lip edge (22); the width W2 of the upper horizontal edge (23) is greater than the width W2' of the lower horizontal edge (24); the sealing member (2) is assembled inside the sealing groove (1); the outer straight sealing lip edge (21) is tightly attached to the outer straight edge (12); the inner straight gap lip edge (22) leaves a gap with the inner straight edge (13); the lower horizontal edge (24) faces the bottom (11) and the upper horizontal edge (23) faces the outlet (14); the sealing side plate (3) covers the outlet (14). The high-pressure oil C flows into the bottom of the sealing groove from the gap between the inner straight gap lip edge (22) and the inner straight edge (13), and acts on the stepped vertical edge, the inner straight gap lip edge (22), the lower horizontal edge (24) and the pressure-bearing edge (25), so as to push the sealing member (2) towards the sealing side plate (3) and the outer straight edge (12); the higher the pressure is, the greater the sealing force is, forming a dynamic self-tight sealing.

2. The end face seal structure of a high-pressure oil pump according to claim 1, characterized by: The difference between H1 and H1' is 0.5-1.5 mm.

3. The end face seal structure of a high-pressure oil pump according to claim 1, characterized by: The difference between W1 and W2 is 0.2-0.4 mm.

4. The end face seal structure of a high-pressure oil pump according to claim 1, characterized by: H2' = 2 / 3H2.

5. The end face seal structure of a high-pressure oil pump according to claim 1, characterized by: W2' = 1 / 2W2.

6. A bi-directional high pressure oil pump characterized by: It comprises the end face sealing structure as claimed in any one of claims 1-5; the bidirectional high-pressure oil pump is used for the hydraulic suspension system of an automobile.

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