Sealing structure for turbocharger

Abstract

The invention discloses a sealing structure for a turbocharger. The sealing structure comprises a shaft sleeve arranged on a rotor shaft of the turbocharger in a sleeving mode, a sealing ring and an air sealing ring. The shaft sleeve is detachably and fixedly installed on the rotor shaft, a first ring groove is formed in the shaft sleeve, an inner ring of the sealing ring is located in the first ring groove, and an outer ring of the sealing ring is matched with the air sealing ring; an inner ring of the sealing ring comprises a first reducing pipe face, the large-diameter end of the first reducing pipe face is connected to the end face, facing an oil cavity of the turbocharger, of the sealing ring, the small-diameter end of the first reducing pipe face is far away from the oil cavity, and the end face, facing the oil cavity of the turbocharger, of the sealing ring abuts against the edge of the inner wall, facing the oil cavity, of a notch of the first ring groove. By arranging the first reducing pipe face, the end face, facing the oil cavity of the turbocharger, of the sealing ring only abuts against the inner wall edge, facing the oil cavity, of the notch of the first ring groove, the contact area is reduced, the reliability of the sealing structure can be improved, the service life of the sealing ring is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of turbochargers, and in particular to a sealing structure for a turbocharger. Background Art

[0002] The oil and gas seal of the supercharger has a very important impact on the reliability of the supercharger. The sealing form is usually a labyrinth and a sealing ring contact seal. The radial turbocharger is limited by the compact structure, and the diesel engine manufacturer has strict requirements on the crankcase pressure when designing the diesel engine. In order to avoid excessive crankcase pressure, the supercharger usually adopts a sealing ring sealing structure. The existing structural sealing ring has a flat side end face. As the wear increases, the thickness of the sealing ring becomes thinner. After the wear is greater than 0.5mm, it needs to be replaced. The service life is short and cannot meet the requirements of modern diesel engine strengthening, power improvement and long-cycle maintenance life. Summary of the invention

[0003] The present invention provides a sealing structure for a turbocharger to solve the above technical problems.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A sealing structure for a turbocharger comprises: a shaft sleeve, a sealing ring and an air seal ring which are sleeved on a rotor shaft of the turbocharger; the shaft sleeve is detachably fixedly mounted on the rotor shaft, a first ring groove is provided on the shaft sleeve, an inner ring of the sealing ring is located in the first ring groove, and an outer ring of the sealing ring cooperates with the air seal ring; the inner ring of the sealing ring comprises a first reducer surface, a large diameter end of the first reducer surface is connected to an end surface of the sealing ring facing an oil chamber of the turbocharger, a small diameter end of the first reducer surface is away from the oil chamber, and an end surface of the sealing ring facing the oil chamber of the turbocharger abuts against an inner wall edge of a notch of the first ring groove facing the oil chamber.

[0006] Preferably, along the radial direction of the first annular groove: the size of the portion where the end surface of the sealing ring facing the oil chamber of the turbocharger abuts against the inner wall edge of the notch of the first annular groove facing the oil chamber is 0.2-0.4 mm.

[0007] Preferably, a dimension of the first reducer surface along the axial direction of the rotor shaft is greater than or equal to 1.0 mm.

[0008] Preferably, the inner ring of the sealing ring further comprises a second reducer surface, the large diameter end of the second reducer surface is connected to the end surface of the sealing ring away from the oil chamber of the turbocharger, and the small diameter end of the second reducer surface faces the oil chamber.

[0009] Preferably, the first reducer surface and the second reducer surface are symmetrically arranged.

[0010] Preferably, an average value of the sum of the dimensions of the first reducer surface and the second reducer surface along the axial direction of the rotor shaft is greater than or equal to 1.0 mm.

[0011] Preferably, the sleeve is interference fitted on the rotor shaft, and the interference fit between the rotor shaft and the sleeve with a diameter in the range of 30-50 mm is controlled in the range of 0.05-0.08 mm.

[0012] Preferably, the shaft sleeve and the rotor shaft are made of the same material.

[0013] Preferably, the inner edge of the air sealing ring includes a positioning section and a matching section, the positioning section is located on the side of the first reducer facing the oil chamber of the turbocharger, and the inner diameter of the positioning section is smaller than the inner diameter of the matching section; the end face of the sealing ring facing the oil chamber of the turbocharger abuts against the step surface formed by the positioning section and the matching section, and the outer periphery of the sealing ring matches with the inner wall of the matching section.

[0014] Preferably, a second annular groove is provided on the mating section, the bottom of the second annular groove is arc-shaped and one side is tangent to the step surface formed by the positioning section and the mating section, and the other side of the bottom of the second annular groove is connected to a slope extending to the inner wall of the mating section and is tangent to the slope.

[0015] Beneficial effects:

[0016] A sealing structure for a turbocharger disclosed in the present application is provided with a first reducing pipe surface so that the end face of the sealing ring facing the oil chamber of the turbocharger only abuts against the inner wall edge of the notch of the first ring groove facing the oil chamber. Compared with the original structure in which the entire end face of the sealing ring contacts the inner wall of the ring groove, the contact area is greatly reduced, the sealing pressure of the sealing surface is improved, and a better sealing effect is achieved for lubricating oil with high oil pressure and high temperature. Moreover, the contact area of ​​the sealing ring is gradually increased to a conventional contact seal after being worn during operation, which can improve the reliability of the sealing structure, extend the service life of the sealing ring, and reduce the maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 It is a structural schematic diagram of a sealing structure for a turbocharger disclosed in the present invention;

[0019] Figure 2 for Figure 1 A partial enlarged view of middle A;

[0020] Figure 3 It is a structural schematic diagram of a first type of sealing ring of a sealing structure for a turbocharger disclosed in the present invention;

[0021] Figure 4 The present invention discloses a structural schematic diagram of a second sealing ring of a sealing structure for a turbocharger.

[0022] 1. Shaft sleeve; 11. First annular groove; 2. Sealing ring; 21. First reducer surface; 22. Second reducer surface; 3. Gas seal ring; 31. Positioning section; 32. Fitting section; 321. Second annular groove; 4. Rotor shaft; 5. Turbine. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0024] A sealing structure for a turbocharger, combined with Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, it includes: a sleeve 1, a sealing ring 2 and an air seal ring 3 which are sleeved on the rotor shaft 4 of the turbocharger; the sleeve 1 is detachably fixedly mounted on the rotor shaft 4, a first annular groove 11 is provided on the sleeve 1, the inner ring of the sealing ring 2 is located in the first annular groove 11, and the outer ring of the sealing ring 2 cooperates with the air seal ring 3; the inner ring of the sealing ring 2 includes a first reducer surface 21, the large diameter end of the first reducer surface 21 is connected to the end surface of the sealing ring 2 facing the oil chamber of the turbocharger, the small diameter end of the first reducer surface 21 is away from the oil chamber, and the end surface of the sealing ring 2 facing the oil chamber of the turbocharger abuts against the inner wall edge of the notch of the first annular groove 11 facing the oil chamber. Without changing the original sealing form, the present application sets a first reducer surface 21 so that the end surface of the sealing ring 2 facing the oil chamber of the turbocharger only abuts against the inner wall edge of the notch of the first annular groove 11 facing the oil chamber, thereby avoiding direct contact between the entire end surface of the sealing ring with a rectangular cross-section and the inner wall of the annular groove, greatly reducing the contact area, and improving the sealing pressure of the sealing surface, which has a better sealing effect on high-pressure and high-temperature lubricating oil, and the contact area of ​​the sealing ring 2 gradually increases after operation wear to become a conventional contact seal, which can improve the reliability of the sealing structure, extend the service life of the sealing ring 2, and reduce maintenance costs.

[0025] At the same time, the sleeve 1 prevents the sealing ring 2 from being directly installed on the rotor shaft 4, which would cause wear and deformation on the contact surface between the sealing ring 2 and the rotor shaft 4, thereby avoiding a large cost waste due to the rotor shaft 4 being unable to be repaired.

[0026] Preferably, along the radial direction of the first annular groove 11: the size of the portion where the end face of the sealing ring 2 facing the oil chamber of the turbocharger and the inner wall edge of the notch of the first annular groove 11 facing the oil chamber is 0.2-0.4mm. That is, in the initial installation state, the width of the contact surface between the end face of the sealing ring 2 facing the oil chamber of the turbocharger and the inner wall edge of the notch of the first annular groove 11 facing the oil chamber is guaranteed to be within the range of 0.2-0.4mm. During the rotation process, under the action of the high-temperature gas, the end face of the sealing ring 2 facing the oil chamber of the turbocharger is kept pressed against the inner wall edge of the notch of the first annular groove 11 facing the oil chamber and a smaller contact area is ensured, thereby ensuring the sealing pressure and achieving a better sealing effect.

[0027] Preferably, the dimension of the first reducer surface 21 along the axial direction of the rotor shaft 4 is greater than or equal to 1.0 mm, that is, H1-H2≥1.0 mm, H1 represents the axial dimension of the sealing ring 2, and H2 represents the axial dimension of the center hole of the sealing ring 2; it is ensured that the sealing ring 2 can still become a conventional contact seal after the contact area gradually increases due to end face wear, so that it can still work reliably after the wear is greater than 0.5 mm.

[0028] Preferably, the inner ring of the sealing ring 2 further includes a second reducer surface 22, the large diameter end of the second reducer surface 22 is connected to the end surface of the sealing ring 2 away from the oil chamber of the turbocharger, and the small diameter end of the second reducer surface 22 faces the oil chamber. When the end surface of the sealing ring 2 corresponding to the first reducer surface 21 is excessively worn, the sealing ring 2 can be turned around, and the end surface of the sealing ring 2 away from the oil chamber of the turbocharger (i.e., the end surface of the sealing ring 2 corresponding to the second reducer surface 22) abuts against the inner wall edge of the notch of the first annular groove 11 facing the oil chamber.

[0029] Preferably, the first reducer surface 21 and the second reducer surface 22 are symmetrically arranged, so that the sealing ring 2 does not need to distinguish between the front and back during installation, which is convenient for installation and debugging; and it is convenient to replace during maintenance.

[0030] Preferably, the average value of the sum of the dimensions of the first reducer surface 21 and the second reducer surface 22 along the axial direction of the rotor shaft 4 is greater than or equal to 1.0 mm, that is, (H3-H4) / 2≥1.0 mm, H3 represents the axial dimension of the sealing ring 2, and H4 represents the axial dimension of the center hole of the sealing ring 2; it is ensured that the sealing ring 2 can still become a conventional contact seal after the contact area gradually increases due to end face wear, so that it can still work reliably after the wear is greater than 0.5 mm.

[0031] Specifically, the first reducer surface 21 and the second reducer surface 22 can be an annular segment of a quadratic cone, an elliptical parabola, a double-leaf hyperboloid, a single-leaf hyperboloid, an ellipsoid, a sphere, etc., so that the contact area of ​​the end face of the sealing ring 2 gradually increases after wear.

[0032] Preferably, the sleeve 1 is interference-fitted on the rotor shaft 4, and the interference between the rotor shaft 4 and the sleeve 1 is controlled within the range of 0.05-0.08 mm for a diameter of 30-50 mm. After long-term use, the worn and deformed sleeve 1 can be removed and replaced with a new sleeve 1, which ensures the sealing effect and prolongs the service life of the rotor shaft 4.

[0033] Preferably, the sleeve 1 and the rotor shaft 4 are made of the same material so that the sleeve 1 and the rotor shaft 4 maintain the same expansion coefficient to prevent the sleeve 1 from loosening after being heated.

[0034] Specifically, the rotor shaft 4 and the core shaft of the turbine 5 are butted and fixedly connected by friction welding, and the sleeve 1 is sleeved at the connection between the rotor shaft 4 and the core shaft of the turbine 5. The core shaft of the turbine 5 is processed with a step to position the sleeve 1. This structural design reduces the diameter of the rotor shaft 4 and the core shaft of the turbine 5 where welding is required, which is conducive to improving the reliability of friction welding.

[0035] Specifically, the outer diameter of the sleeve 1 is less than or equal to the outer diameter of the step on the core shaft of the turbine 5, so as to prevent the sleeve 1 from protruding from the step on the core shaft and expanding directly under the influence of high-temperature gas, thereby preventing the sleeve 1 from loosening due to an increase in temperature difference with the rotor shaft 4.

[0036] Preferably, the inner ring of the gas sealing ring 3 includes a positioning section 31 and a matching section 32, the positioning section 31 is located on the side of the first reducer surface 21 facing the oil chamber of the turbocharger, and the inner diameter of the positioning section 31 is smaller than the inner diameter of the matching section 32; the end face of the sealing ring 2 facing the oil chamber of the turbocharger abuts against the step surface formed by the positioning section 31 and the matching section 32, and the outer periphery of the sealing ring 2 matches with the inner wall of the matching section 32; the position of the sealing ring 2 is ensured, thereby ensuring that the end face of the sealing ring 2 facing the oil chamber of the turbocharger and the notch of the first ring groove 11 face the inner wall edge of the oil chamber, the end face of the sealing ring 2 facing the oil chamber of the turbocharger and the step surface formed by the positioning section 31 and the matching section 32 are in reliable contact.

[0037] Preferably, the mating section 32 is provided with a second annular groove 321, the bottom of the second annular groove 321 is arc-shaped and one side is tangent to the step surface formed by the positioning section 31 and the mating section 32, and the other side of the bottom of the second annular groove 321 is connected to an inclined surface extending to the inner wall of the mating section 32 and is tangent to the inclined surface. The second annular groove 321 is cleaned for the root of the step surface formed by the positioning section 31 and the mating section 32 to ensure that the end face of the sealing ring 2 facing the oil chamber of the turbocharger and the step surface formed by the positioning section 31 and the mating section 32 can be in close contact.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sealing structure for a turbocharger, characterized in that: include: A shaft sleeve (1), a sealing ring (2) and an air seal ring (3) are sleeved on a rotor shaft (4) of a turbocharger; the shaft sleeve (1) is detachably fixedly mounted on the rotor shaft (4); a first annular groove (11) is provided on the shaft sleeve (1); an inner ring of the sealing ring (2) is located in the first annular groove (11); an outer ring of the sealing ring (2) cooperates with the air seal ring (3); the inner ring of the sealing ring (2) comprises a first reducer surface (21); a large diameter end of the first reducer surface (21) is connected to an end surface of the sealing ring (2) facing an oil chamber of the turbocharger; a small diameter end of the first reducer surface (21) is away from the oil chamber; an end surface of the sealing ring (2) facing the oil chamber of the turbocharger abuts against an inner wall edge of a notch of the first annular groove (11) facing the oil chamber.

2. A sealing structure for a turbocharger according to claim 1, characterized in that: Along the radial direction of the first annular groove (11): the size of the portion where the end surface of the sealing ring (2) facing the oil chamber of the turbocharger and the notch of the first annular groove (11) facing the inner wall edge of the oil chamber are in contact is 0.2-0.4 mm.

3. A sealing structure for a turbocharger according to claim 1, characterized in that: The dimension of the first reducer surface (21) along the axial direction of the rotor shaft (4) is greater than or equal to 1.0 mm.

4. A sealing structure for a turbocharger according to claim 1, characterized in that: The inner ring of the sealing ring (2) also includes a second reducer surface (22), the large diameter end of the second reducer surface (22) being connected to the end surface of the sealing ring (2) away from the oil chamber of the turbocharger, and the small diameter end of the second reducer surface (22) facing the oil chamber.

5. A sealing structure for a turbocharger according to claim 4, characterized in that: The first reducing pipe surface (21) and the second reducing pipe surface (22) are symmetrically arranged.

6. A sealing structure for a turbocharger according to claim 4 or 5, characterized in that: The average value of the sum of the dimensions of the first reducer surface (21) and the second reducer surface (22) along the axial direction of the rotor shaft (4) is greater than or equal to 1.0 mm.

7. The sealing structure for a turbocharger according to claim 1, characterized in that: The shaft sleeve (1) is interference-fitted on the rotor shaft (4), and the interference fit between the rotor shaft (4) and the shaft sleeve (1) is controlled within the range of 0.05-0.08 mm for a diameter within the range of 30-50 mm.

8. The sealing structure for a turbocharger according to claim 1, characterized in that: The shaft sleeve (1) and the rotor shaft (4) are made of the same material.

9. The sealing structure for a turbocharger according to claim 1, characterized in that: The inner edge of the gas seal ring (3) comprises a positioning section (31) and a matching section (32); the positioning section (31) is located on the side of the first reducer surface (21) facing the oil chamber of the turbocharger, and the inner diameter of the positioning section (31) is smaller than the inner diameter of the matching section (32); the end surface of the sealing ring (2) facing the oil chamber of the turbocharger abuts against the step surface formed by the positioning section (31) and the matching section (32), and the outer periphery of the sealing ring (2) matches with the inner wall of the matching section (32).

10. A sealing structure for a turbocharger according to claim 9, characterized in that: The mating section (32) is provided with a second annular groove (321), the bottom of the second annular groove (321) is arc-shaped and one side of the bottom of the second annular groove (321) is tangent to a step surface formed by the positioning section (31) and the mating section (32), and the other side of the bottom of the second annular groove (321) is connected to an inclined surface extending to the inner wall of the mating section (32) and is tangent to the inclined surface.

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