Low-leakage combined groove type mechanical sealing piece suitable for high-rotating-speed working condition

Abstract

The invention relates to the field of mechanical sealing, in particular to a low-leakage combined groove type mechanical sealing piece suitable for a high-rotating-speed working condition, and an outer combined groove extending inwards from an outer ring of the sealing piece and an inner combined groove extending outwards from an inner ring of the sealing piece are formed in the sealing face of the sealing piece; the outer combined groove is of a V-shaped groove structure, an opening is formed in the V-shaped tip of the outer combined groove and faces the outer side of the sealing piece, and the outer combined groove is arranged in an axial symmetry mode in the radial direction of the sealing piece; the inner combined groove comprises straight-line-shaped long groove sections and straight-line-shaped short groove sections which are alternately arranged in the circumferential direction of the sealing piece, the straight-line-shaped long groove sections and the straight-line-shaped short groove sections are rectangular grooves arranged in the radial direction of the sealing piece, and the ends, facing the inner side of the sealing piece, of the straight-line-shaped long groove sections and the straight-line-shaped short groove sections are open. The groove shape of the sealing fin is improved, so that the sealing fin adapts to the high-rotating-speed operation working condition, and the sealing effect of the sealing fin is greatly improved.

Description

Technical Field

[0001] The invention relates to the field of mechanical seals, in particular to a low-leakage combined groove-type mechanical seal sheet suitable for high-speed working conditions. Background Art

[0002] In the field of fluid sealing, various mechanical equipment are developing towards high speed and high pressure, and the sealing problem of the shaft seal system of high-speed centrifugal pumps is becoming more and more important. As a non-contact seal, mechanical seals have significant advantages such as low leakage, low wear and long life, and have gradually become the best choice for the shaft seal system of high-speed centrifugal pumps.

[0003] In actual operation, a variety of classic grooves are selectively opened on the surface of the sealing plate of the mechanical seal to improve the sealing performance, such as the boot-shaped groove described in the application number "201120486065.3" and the classic spiral groove. Such conventional groove sealing plates are widely used in medium and low speed centrifugal pumps, but when they are applied to high speed centrifugal pumps, they will have a high leakage rate problem, poor stability during long-term high-speed operation, and unable to cope with the challenges of mechanical vibration or other emergencies. The sealing effect under high speed conditions cannot meet the design requirements, so it needs to be solved urgently. Summary of the invention

[0004] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a low leakage combined groove type mechanical seal suitable for high speed working conditions. The present invention improves the groove type of the seal to adapt to high speed operating conditions and greatly improves the sealing effect of the seal.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A low-leakage combined groove type mechanical seal suitable for high-speed working conditions, wherein an outer combined groove extending inward from an outer ring of the seal and an inner combined groove extending outward from an inner ring of the seal are provided on a sealing surface of the seal; the outer combined groove is in a V-shaped groove structure, with an opening at the V-shaped tip and the opening facing the outside of the seal, and the outer combined groove is arranged in an axisymmetric manner along the radial direction of the seal; the inner combined groove comprises a straight long groove section and a straight short groove section alternately arranged in the circumferential direction of the seal, the straight long groove section and the straight short groove section are both rectangular grooves arranged in the radial direction of the seal, and the straight long groove section and the straight short groove section are open toward one end of the inner side of the seal.

[0007] As a further solution of the present invention: starting from the opening of the outer combined groove, the groove body depth of the outer combined groove gradually decreases from the outside to the inside on the sealing sheet.

[0008] As a further solution of the present invention, a rectangular coordinate system is established with the symmetry axis of the outer combined groove as the Y axis, and the groove depth h of the outer combined groove corresponding to the X-axis coordinate is calculated from the X-axis of the rectangular coordinate system in the direction away from the coordinate point. v (x v )for:

[0009]

[0010] Where: w v is the width of the outer combination groove 20 in the X-axis direction;

[0011] h v,max It is the maximum depth of the outer combined groove 20.

[0012] As a further solution of the present invention: the groove depth of the outer combination groove ranges from 1 to 5 μm.

[0013] As a further solution of the present invention: an even number of groups of outer combination grooves are provided, and any outer combination groove is arranged to coincide with the symmetry axis of the one-word long groove segment of a corresponding group of inner combination grooves.

[0014] As a further solution of the present invention: the groove body depth of the inner combined groove is constant, the ratio of the groove length to the groove width of the inner combined groove is 1-2, and the ratio of the groove depth to the groove length of the inner combined groove is 0.1-0.8.

[0015] As a further solution of the present invention: the groove curve of the outer combined groove includes a starting section located in the outer circle of the sealing plate and is in the shape of an arc surface, with the starting section as the opening of the outer combined groove, and the outer combined groove extends inward to form two groups of symmetrical groove sections, with the starting section as the starting point of the symmetrical groove section, and the ending section as the end point of the symmetrical groove section, both ends of the starting section are connected to one end of the ending section through a first transition section, and adjacent ends of the two groups of ending sections are connected to form a V-shaped groove; the symmetry axis of the outer combined groove is taken as the Y-axis, and a rectangular coordinate system is established with the axis center of the sealing plate as the origin, and the end sections of the two symmetrical groove sections are arranged parallel to the X-axis of the rectangular coordinate system.

[0016] As a further solution of the present invention: the first transition section is a straight section, the end of the terminal section away from the first transition section is connected to the second transition section, the second transition section is arranged parallel to the first transition section, the two groups of second transition sections are connected by a closed section, and the closed section is arranged parallel to the terminal section.

[0017] As a further solution of the present invention: the first transition segment is a straight line segment, and the adjacent ends of the two groups of terminal segments are connected by a closed segment, and the closed segment is a parabola.

[0018] As a further solution of the present invention: the first transition section is a parabola, the end of the terminal section away from the first transition section is connected to the second transition section, the second transition section is arranged parallel to the first transition section, the two groups of second transition sections are connected by a closed section, and the closed section is arranged parallel to the terminal section.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention is provided with different combination groove types on the inner and outer sides of the sealing plate. The outer combination groove is a bilaterally symmetrical V-shaped groove structure, and the inner combination groove is an alternating arrangement of long and short rectangular grooves. By forming multiple high-pressure areas on the sealing end face, the dynamic pressure effect is significantly enhanced, the opening force of the sealing end face is improved, and it is beneficial to the heat dissipation of the end face liquid film seal, which is suitable for high-speed operating conditions and greatly improves the sealing effect of the sealing plate.

[0021] 2. The combined design of the outer combined groove and the inner combined groove of the present invention enhances liquid disturbance, destroys the boundary layer, enhances heat exchange, reduces the temperature of the sealing end surface, reduces the wear degree of the sealing sheet, and can be applied to a wider range of working conditions.

[0022] 3. The present invention increases the liquid film pressure, enhances the dynamic pressure effect, reduces the friction during seal startup, and is beneficial to the stability of the liquid film performance through the alternating rectangular groove layout of the internal combination grooves. The arrangement, size and number of the internal combination grooves can be flexibly adjusted, which is suitable for a variety of working conditions and structures and is simple to process.

[0023] 4. The inner combined groove of the present invention serves as the part that receives the entry of high-pressure fluid, while the outer combined groove serves as the part that discharges low-pressure fluid. The combined design significantly improves the opening ability of the sealing end face, reduces the end face temperature, reduces the leakage, is easy to process, has good scalability, and is adaptable to complex operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 FIG. 1 is a schematic structural diagram of a first embodiment of the present invention.

[0025] Figure 2 for Figure 1 A partial enlarged view of .

[0026] Figure 3 FIG. 2 is a schematic structural diagram of a second embodiment of the present invention.

[0027] Figure 4 for Figure 3 A partial enlarged view of .

[0028] Figure 5 FIG. 2 is a schematic structural diagram of a second embodiment of the present invention.

[0029] Figure 6 for Figure 5 A partial enlarged view of .

[0030] Figure 7 It is a pressure distribution cloud diagram under the operating conditions of the present invention.

[0031] In the figure:

[0032] 10. Sealing sheet; 20. External combination groove;

[0033] 201, starting section; 202, first transition section;

[0034] 203, second transition section; 204, final section; 205, closing section;

[0035] 30. Inner combined groove; 301. Slotted long groove section; 302. Slotted short groove section. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] See also Figures 1 to 7 In an embodiment of the present invention, a low-leakage combined groove type mechanical seal is suitable for high-speed working conditions. The outer ring of the sealing surface of the seal 10 is evenly provided with external combined grooves 20 along the circumferential direction. The external combined grooves 20 are evenly spaced and designed symmetrically along the radial axis of the seal 10.

[0038] The outer combination groove 20 is designed in a V-shape as a whole, with the tip facing the outside of the sealing sheet 10 and an opening at the tip. The arc-shaped opening contour of the outer combination groove 20 at the outer end surface of the sealing sheet 10 is the starting section 201 of the contour curve of the outer combination groove 20. Starting from the starting section 201, the outer combination groove 20 extends to the inside of the sealing sheet 10 to form two groups of symmetrical groove bodies. The two groups of groove bodies cooperate to form a V-shaped groove. The specific structural form is as follows:

[0039] Embodiment 1, as Figure 2 As shown, the two ends of the starting section 201 are connected to the first transition section 202 which is arranged in a straight line and inclined, the first transition section 202 is connected to one end of the terminal section 204, the second transition section 203 which is arranged parallel to the first transition section 202 is connected to the other end of the terminal section 204, and the two groups of second transition sections 203 are connected by a closing section 205 to close the contour curve of the outer combined groove 20.

[0040] In this embodiment, the symmetry axis of the outer combination groove 20 is the Y axis, and a rectangular coordinate system is established with the axis center of the sealing sheet 10 as the origin. The two groups of terminal segments 204 and the two groups of closed segments 205 are arranged parallel to the X axis of the rectangular coordinate system.

[0041] In this rectangular coordinate system, the coordinate equation of the starting segment 201 is x 2 +y2 =R 2 ;

[0042] Wherein, R is the outer diameter of the sealing ring 10 .

[0043] The coordinate equation of the first transition section 202 is y=x+R+w v ;

[0044] Wherein: 0≤x≤-R; another group of first transition sections 202 are arranged symmetrically about the Y axis of the rectangular coordinate system.

[0045] The coordinate equation of the second transition section 203 is y=x+R;

[0046] Wherein: 0≤x≤-R or 0≤x≤R; another group of second transition sections 203 are arranged symmetrically about the Y axis of the rectangular coordinate system.

[0047] The coordinate equation of the terminal section 204 is y=h g ;

[0048] h g It is the average value of the sum of the inner diameter and the outer diameter of the sealing sheet 10;

[0049] The coordinate equation of the closed segment 205 is y=Rw v .

[0050] Embodiment 2, as Figure 4 As shown, the two ends of the starting section 201 are connected with the first transition sections 202 which are arranged in a straight line and inclined. The first transition sections 202 are connected to one end of the terminal section 204. The two groups of first transition sections 202 are connected by a closing section 205 to close the contour curve of the outer combined groove 20.

[0051] In this embodiment, the symmetry axis of the outer combined groove 20 is the Y axis, and a rectangular coordinate system is established with the axis center of the sealing sheet 10 as the origin. The two groups of terminal segments 204 are arranged parallel to the X axis of the rectangular coordinate system, and the closed segment 205 is a parabola.

[0052] In this rectangular coordinate system, the coordinate equation of the starting segment 201 is x 2 +y 2 =R 2 ;

[0053] Wherein, R is the outer diameter of the sealing ring 10 .

[0054] The coordinate equation of the first transition section 202 is y=x+R+w v ;

[0055] Wherein: 0≤x≤-R; another group of first transition sections 202 are arranged symmetrically about the Y axis of the rectangular coordinate system.

[0056] The coordinate equation of the terminal section 204 is y=h g ;

[0057] h g It is the average value of the sum of the inner diameter and the outer diameter of the sealing sheet 10.

[0058] The coordinate equation of the closed segment 205 is y=-0.04x 2 +R-2w v .

[0059] The curves of each segment intersect to form a groove profile.

[0060] Embodiment three, as Figure 6 As shown, the two ends of the starting section 201 are connected to the first transition section 202, the first transition section 202 is a parabola, the first transition section 202 is connected to one end of the terminal section 204, the second transition section 203 arranged parallel to the first transition section 202 is connected to the other end of the terminal section 204, and the two groups of second transition sections 203 are connected by a closing section 205 to close the contour curve of the outer combined groove 20.

[0061] In this embodiment, the symmetry axis of the outer combination groove 20 is the Y axis, and a rectangular coordinate system is established with the axis center of the sealing sheet 10 as the origin. The two groups of terminal segments 204 and the two groups of closed segments 205 are arranged parallel to the X axis of the rectangular coordinate system.

[0062] In this rectangular coordinate system, the coordinate equation of the starting segment 201 is x 2 +y 2 =R 2 ;

[0063] Wherein, R is the outer diameter of the sealing ring 10 .

[0064] The coordinate equation of the first transition section 202 is y=-0.04x 2 +R+w v ;

[0065] The coordinate equation of the second transition section 203 is y=-0.08x 2 +Rw v ;

[0066] The coordinate equation of the terminal section 204 is y=h g ;

[0067] h g It is the average value of the sum of the inner diameter and the outer diameter of the sealing sheet 10.

[0068] The coordinate equation of the closed segment 205 is y=Rw v .

[0069] The curves of each segment intersect to form a groove profile.

[0070] In the above-mentioned embodiments, the opening of the outer combination groove 20 is taken as the starting point, and the groove depth of the outer combination groove 20 gradually decreases from the outside to the inside on the sealing sheet 10 .

[0071] A rectangular coordinate system is established with the symmetry axis of the outer combination groove 20 as the Y axis. From the X axis of the rectangular coordinate system in the direction away from the coordinate origin, the groove depth h of the outer combination groove corresponding to the X axis coordinate is v (x v )for:

[0072]

[0073] Where: w v is the width of the outer combination groove 20 in the X-axis direction;

[0074] h v,max The maximum depth of the outer combination groove 20 is 5 μm, and the minimum depth is 1 μm. The number of the outer combination grooves 20 is an even number, and the total number of grooves is 2 to 12 groups, and the span along the circumferential direction of the sealing sheet 10 is 25° to 36°.

[0075] The inner ring of the sealing surface of the sealing sheet 10 is uniformly provided with inner combination grooves 30 along the circumferential direction. The inner combination grooves 30 include alternating long groove segments 301 and short groove segments 302. The long groove segments 301 and the short groove segments 302 are open toward one end of the inner side of the sealing sheet 10. The long groove segments 301 and the short groove segments 302 are both rectangular grooves, and the depth of the groove body is constant along the groove length direction. The ratio of the groove length to the groove width of the inner combination groove 30 is 1 to 2, and the ratio of the groove depth to the groove length of the inner combination groove 30 is 0.1 to 0.8. A group of long groove segments 301 and a group of short groove segments 302 constitute a group of inner combination grooves 30. The number of inner combination grooves 30 is preferably twice the number of outer combination grooves 20. Any outer combination groove 20 is arranged to coincide with the symmetry axis of the long groove segments 301 of one group of inner combination grooves 30.

[0076] As shown in Table 1 below, Table 1 shows the sealing end face opening force data of the sealing piece of the present invention at different speeds and pressures. Taking the operating conditions of a speed of 10000r / min and a pressure of 0.8MPa as an example, the opening force of a conventional spiral groove sealing piece is 4433.84. Under the same pressure and speed, the sealing piece of the present invention has a sealing piece opening force similar to that of a conventional spiral groove sealing piece. At the same time, the sealing piece of the present invention has the advantages of bidirectional rotation and low leakage.

[0077] Table 1

[0078]

[0079] As shown in Table 2 below, Table 2 shows the sealing end face leakage rate data of the sealing sheet of the present invention at different speeds and pressures. Taking the operating conditions of a speed of 15000r / min and a pressure of 0.8MPa as an example, the leakage rate of the existing spiral groove sealing sheet is 0.02051kg / s, and the leakage rate of the sealing sheet of the present invention is much lower than the leakage rate of the conventional spiral groove sealing sheet. Under the operating conditions of a speed of 15000r / min and a pressure of 0.8MPa, the pressure distribution cloud diagram of the present invention is as follows: Figure 7 As shown, it can be seen that the present invention has a very strong dynamic pressure effect.

[0080] Table 2

[0081]

[0082] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0083] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

Claims

1. A low leakage combined groove type mechanical seal suitable for high speed working conditions, characterized in that: An outer combined groove (20) extending inward from the outer ring of the sealing plate (10) and an inner combined groove (30) extending outward from the inner ring of the sealing plate (10) are provided on the sealing surface of the sealing plate (10); the outer combined groove (20) is in a V-shaped groove structure, with an opening at the V-shaped tip and the opening facing the outside of the sealing plate (10); the outer combined groove (20) is arranged in an axisymmetric manner along the radial direction of the sealing plate (10); the inner combined groove (30) comprises a straight long groove section (301) and a straight short groove section (302) alternately arranged in the circumferential direction of the sealing plate (10); the straight long groove section (301) and the straight short groove section (302) are both rectangular grooves arranged in the radial direction of the sealing plate (10); the straight long groove section (301) and the straight short groove section (302) are open at one end facing the inside of the sealing plate (10).

2. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to claim 1, characterized in that: Taking the opening of the outer combined groove (20) as the starting point, the groove body depth of the outer combined groove (20) gradually decreases from the outside to the inside on the sealing sheet (10).

3. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to claim 2, characterized in that: A rectangular coordinate system is established with the symmetry axis of the outer combined groove (20) as the Y axis. From the X axis of the rectangular coordinate system in the direction away from the coordinate circle, the groove depth h of the outer combined groove corresponding to the X axis coordinate is v (x v )for: Where: w v is the width of the outer combined groove (20) in the X-axis direction; h v,max It is the maximum depth of the outer combined groove (20).

4. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to claim 2 or 3, characterized in that: The groove depth of the outer combined groove (20) ranges from 1 to 5 μm.

5. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to any one of claims 1 to 4, characterized in that: The outer combination grooves (20) are arranged in an even number, and the symmetry axis of any outer combination groove (20) and a corresponding one group of inner combination grooves (30) are arranged to coincide with each other.

6. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to any one of claims 1 to 4, characterized in that: The groove body depth of the inner combined groove (30) is constant, the ratio of the groove length to the groove width of the inner combined groove (30) is 1 to 2, and the ratio of the groove depth to the groove length of the inner combined groove (30) is 0.1 to 0.

8.

7. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to any one of claims 1 to 4, characterized in that: The groove curve of the outer combined groove (20) comprises a starting section (201) located on the outer circle of the sealing plate (10) and in the shape of an arc surface. The starting section (201) serves as the opening of the outer combined groove (20). The outer combined groove (20) extends inward to form two groups of symmetrical groove sections. The starting section (201) serves as the starting point of the symmetrical groove section, and the ending section (204) serves as the ending point of the symmetrical groove section. Both ends of the starting section (201) are connected to one end of the ending section (204) through a first transition section (202), and adjacent ends of the two groups of ending sections (204) are connected to form a V-shaped groove. A rectangular coordinate system is established with the symmetry axis of the outer combined groove (20) as the Y axis and the axis center of the sealing plate (10) as the origin. The ending sections (204) of the two symmetrical groove sections are arranged parallel to the X axis of the rectangular coordinate system.

8. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to claim 7, characterized in that: The first transition section (202) is a straight section, and the end of the terminal section (204) away from the first transition section (202) is connected to the second transition section (203), the second transition section (203) and the first transition section (202) are arranged in parallel, and the two groups of second transition sections (203) are connected by a closed section (205), and the closed section (205) and the terminal section (204) are arranged in parallel.

9. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to claim 7, characterized in that: The first transition section (202) is a straight line section, and the adjacent ends of the two groups of terminal sections (204) are connected by a closed section (205), and the closed section (205) is a parabola.

10. A low leakage combined groove type mechanical seal suitable for high speed working conditions according to claim 7, characterized in that: The first transition section (202) is a parabola, and the end of the terminal section (204) away from the first transition section (202) is connected to the second transition section (203), the second transition section (203) and the first transition section (202) are arranged in parallel, and the two groups of second transition sections (203) are connected by a closed section (205), and the closed section (205) and the terminal section (204) are arranged in parallel.

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