Turbocharger sealing structure

Abstract

The utility model provides a turbocharger sealing structure, which relates to the field of turbochargers, including a sealing sleeve sleeved on the outer wall of a turbine shaft, one end of the sealing sleeve abutting against a thrust ring on an intermediate body, and also including a sealing ring, a sealing flange protruding outwardly arranged on the outer wall of the sealing sleeve, one end of the sealing ring abutting against a side of the sealing flange away from the thrust ring for relative rotation, and a plurality of spiral grooves uniformly distributed along the circumferential direction are provided on the end surface where the sealing flange and the sealing ring cooperate; the other end of the sealing ring is axially slidably and sealably matched with a back plate, and the other side of the sealing flange abuts against a thrust bearing on the intermediate body; an elastic element is arranged between the end of the sealing ring away from the sealing flange and the back plate, so that the sealing ring always has a tendency to move toward one side of the sealing flange. The turbocharger sealing structure has a simple structure, is easy to install, and meets the requirements of efficient sealing and reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of superchargers, and in particular to a turbocharger sealing structure. Background Art

[0002] Due to the harsh working environment of the whole vehicle, commercial vehicle superchargers are very likely to cause problems such as air filter blockage and poor oil return, which in turn causes the gas pressure on the air side of the supercharger compression end to be less than the oil-gas mixture pressure in the oil chamber, ultimately leading to oil leakage at the compression end. Therefore, the latest supercharger compression end on the market uses a labyrinth seal structure with two piston rings (seals) as standard. The clearance requirements for piston rings and matching parts are becoming more and more stringent. The resulting cost of piston rings and matching parts has also risen rapidly. If the quality control of small clearances is not in place, it is also easy to cause different types of failures such as wear and stagnation.

[0003] For example, the supercharger sealing structure and vehicle disclosed in patent CN209340200U have two sealing rings between the outer peripheral wall of the sealing section of the shaft seal and the inner hole wall of the back plate. The two sealing rings are horizontally limited by the sealing groove of the shaft seal and form a labyrinth structure with a very small gap together with the sealing groove of the shaft seal. The sealing structure in the prior art relies solely on sealing rings for sealing. In the harsh vehicle operating environment, there is a risk of oil leakage due to fluctuations and offsets of the turbine shaft, and the sealing effect is poor. Utility Model Content

[0004] In order to overcome at least one of the defects in the above prior art, the utility model provides a turbocharger sealing structure with simple structure, stable sealing performance and convenient installation.

[0005] The utility model provides a turbocharger sealing structure: comprising a shaft seal, the shaft seal comprising a sealing sleeve sleeved on the outer wall of the turbine shaft, one end of the sealing sleeve abutting against a thrust ring on an intermediate body, and also comprising a sealing ring, a sealing flange protruding outwardly arranged on the outer wall of the sealing sleeve, one end of the sealing ring abutting against a side of the sealing flange away from the thrust ring in a relatively rotatable manner, and a plurality of spiral grooves uniformly distributed along the circumferential direction are provided on the end surfaces of the sealing flange and the sealing ring in cooperation; the other end of the sealing ring is slidably and sealingly matched with a back plate in the axial direction, and the other side of the sealing flange abuts against the thrust bearing on the intermediate body; an elastic element is arranged between the end of the sealing ring away from the sealing flange and the back plate, so that the sealing ring always has a tendency to move toward one side of the sealing flange.

[0006] Compared with the prior art, the turbocharger sealing structure of the utility model has the following advantages:

[0007] In the turbocharger sealing structure of the utility model, a relatively rotatable dynamic sealing structure is formed by the sealing ring and the sealing flange end face of the shaft seal, wherein the sealing flange rotates with the turbine shaft, and it is a dynamic ring, and the sealing ring is a static ring; in addition, the elastic element is arranged so that the sealing ring always abuts against the sealing flange end face, thereby ensuring the sealing performance and timely compensating for the wear of the sealing surface; on the other hand, in this structure, the elastic element is arranged at the static ring end, and does not rotate with the turbine shaft, and the compensation performance is more stable; more importantly, a special structure spiral groove is processed on the sealing surface of the sealing flange as a dynamic ring, which is used for turbocharger When the turbocharger is running at low speed, the graphite ring and the sealing flange rotate relative to each other, and the spiral groove on the surface of the sealing flange forms a dynamic air pressure, but it is not enough to overcome the elastic force of the wave spring, so the shaft seal and the graphite ring surface are still in contact, maintaining zero leakage. When the speed of the turbocharger rises to a certain value, the dynamic air pressure formed by the spiral groove structure on the surface of the sealing flange overcomes the elastic force of the wave spring, and the shaft seal and the graphite ring surface are separated to form a high-pressure air film, which still prevents oil leakage and achieves the purpose of separating the static ring and the dynamic ring under high speed conditions, ultimately achieving the effect of meeting the requirements of high-efficiency sealing and reliability.

[0008] As an improvement, an annular mounting groove is concavely provided on one side of the back plate close to the intermediate body, and the mounting groove has a U-shaped cross-section. A mounting boss slidably fitted into the mounting groove is provided at the end of the sealing ring away from the sealing flange, and a sealing ring is provided between the inner wall of the mounting boss and the radial inner wall of the mounting groove.

[0009] In a further improvement, the sealing ring is a star-shaped sealing ring, and a sealing groove is concavely provided on the radial inner side wall of the mounting groove. The inner end of the star-shaped sealing ring is fitted in the sealing groove, and the outer end is sealed with the inner side wall of the mounting boss. In the above improved structure, the star-shaped sealing ring is used as a seal of the sliding mating surface. When the sealing ring reciprocates, the sealing ring will not turn over or twist, thereby ensuring a more stable sealing performance.

[0010] In a further improvement, a positioning step is provided at one end of the sealing ring away from the sealing flange and located radially outside the mounting boss, and both ends of the elastic element are respectively in contact with the positioning step and the bottom wall of the mounting groove. In the above improved structure, the positioning step makes the limiting of the elastic element more stable, thereby providing a more stable elastic compensation force to ensure the sealing between the sealing ring and the sealing flange.

[0011] In a further improvement, the sealing element is a wave spring, which is sleeved on the outside of the mounting boss, and its two ends are respectively in contact with the positioning step and the bottom wall of the mounting groove. In the above improved structure, the wave spring is selected as the elastic compensation element, the elastic force is more accurately controllable, and the wave spring has a smaller axial size when providing the same elastic force, thereby saving axial installation space and making room for the installation of other components.

[0012] In a further improvement, a plurality of spiral grooves evenly distributed along the circumferential direction are provided on the end surface of the sealing flange abutting against the sealing ring. In the above improved structure, a special spiral groove structure is designed on the shaft seal, which contacts at low speed and disengages at high speed, thereby ensuring the sealing performance and avoiding the risk of high speed wear failure.

[0013] Preferably, the sealing ring is a graphite ring. In this structure, the sealing ring is made of graphite material, and graphite itself has a good self-lubricating effect, which can better ensure the sealing performance between the sealing flange and the sealing ring.

[0014] In a further improvement, an annular positioning groove is provided on the outer peripheral wall of the sealing sleeve away from the intermediate body. In the above improved structure, an annular positioning groove is added to the pressure end side of the shaft seal for clamping by a tool. During assembly, the tool can assemble the back plate, spring, sealing ring, graphite ring, shaft seal and other parts to the intermediate body at one time by clamping the sealing sleeve, thereby improving assembly efficiency.

[0015] Other improved features and advantages of the utility model will be described in the subsequent specific embodiments, and partly become apparent from the description, or understood by implementing the utility model. The purpose and other advantages of the utility model can be achieved and obtained through the structures specifically pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of the turbocharger sealing structure of the utility model applied to a supercharger;

[0017] Figure 2 for Figure 1 The X in the figure is a magnified structural diagram;

[0018] Figure 3 It is a cross-sectional view of the shaft seal in the utility model;

[0019] Figure 4 It is the front view of the shaft seal in the utility model.

[0020] Description of reference numerals:

[0021] 1. Sealing sleeve; 2. Thrust ring; 3. Sealing ring; 4. Sealing flange; 5. Spiral groove; 6. Thrust bearing; 7. Elastic element; 8. Mounting groove; 9. Mounting boss; 10. Sealing ring; 11. Sealing groove; 12. Positioning step; 13. Positioning groove; 14. Intermediate body; 15. Back plate; 16. Turbine shaft. DETAILED DESCRIPTION

[0022] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0023] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "fixed" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances. The present application is further described in detail below in conjunction with the drawings and specific embodiments.

[0024] See also Figure 1 to Figure 4 As shown, an embodiment of the present application discloses a turbocharger sealing structure, including a shaft seal, the shaft seal includes a sealing sleeve 1 sleeved on the outer wall of a turbine shaft 16, one end of the sealing sleeve 1 abuts against a thrust ring 2 on an intermediate body 14; the sealing structure also includes a sealing ring 3, a sealing flange 4 is convexly arranged on the outer wall of the sealing sleeve 1, one end of the sealing ring 3 abuts against a side of the sealing flange 4 away from the thrust ring 2 so as to be relatively rotatable to form a sealing surface, and a plurality of spiral grooves 5 uniformly distributed along the circumferential direction are provided on the end surfaces of the sealing flange 4 and the sealing ring 3 that cooperate with each other; specifically, the spiral grooves 5 here are all closed grooves, which are surrounded by two arc edges concentric with the sealing flange 4 and two spiral edges rotating counterclockwise, wherein the helix angle of the two spiral edges is between 5° and 30°, and the depth of the spiral groove 5 is between 0.01mm and 0.05mm.

[0025] See the attached Figure 2 The other end of the sealing ring 3 is axially slidable and sealed with the back plate 15, and the other side of the sealing flange 4 is in contact with the thrust bearing 6 on the intermediate body 14; an elastic element 7 is provided between the end of the sealing ring 3 away from the sealing flange 4 and the back plate 15, so that the sealing ring 3 always has a tendency to move toward one side of the sealing flange 4.

[0026] In this structure, a contact seal structure is used instead of the piston ring labyrinth seal structure, and a special structure spiral groove is processed on the end face of the sealing flange 4 serving as the dynamic ring, so as to achieve the purpose of disengaging the static ring and the dynamic ring under high speed conditions, ultimately achieving the effect of meeting the requirements of high-efficiency sealing and reliability.

[0027] In addition, in the above structure, the sealing ring 3 is preferably a graphite ring. Graphite has self-lubricating properties, thereby increasing the lubricity between the sealing surfaces and extending the service life of the seal.

[0028] On the other hand, please refer to the attached Figure 2 In the above structure, a side of the back plate 15 close to the intermediate body 14 is concavely provided with an annular mounting groove 8, and the cross section of the mounting groove 8 is U-shaped, and the end of the sealing ring 3 away from the sealing flange 4 is provided with a mounting boss 9 slidably fitted in the mounting groove 8, and a sealing ring 10 is provided between the inner wall of the mounting boss 9 and the radial inner wall of the mounting groove 8. Preferably, the sealing ring 10 is a star-shaped sealing ring 10, and a sealing groove 11 is concavely provided on the radial inner wall of the mounting groove 8. The inner end of the star-shaped sealing ring 10 is fitted in the sealing groove 11, and the outer end is sealed with the inner wall of the mounting boss 9. In this structure, the back plate is directly used as the outer shell of the elastic element 7, the sealing ring 3 and the sealing ring 10, that is, the elastic element 7, the sealing ring 3 and the sealing ring 10 are pre-installed as a whole with the back plate 1, which not only reduces the cost, but also reduces the cumulative tolerance of the dimensional chain, improves the accuracy, and avoids the risk of the outer shell and the back plate 15 not fitting in place.

[0029] In this embodiment, a positioning step 12 is provided at one end of the sealing ring 3 away from the sealing flange 4 and located radially outside the mounting boss 9, and the two ends of the elastic element 7 are respectively in contact with the positioning step 12 and the bottom wall of the mounting groove 8 to ensure the stability of the mounting structure of the elastic element 7. Preferably, the sealing element is a wave spring, which is sleeved on the outside of the mounting boss 9, and its two ends are respectively in contact with the positioning step 12 and the bottom wall of the mounting groove 8. The wave spring is selected as the elastic compensation element, and the elastic force is more accurately controllable, and the wave spring has a smaller axial dimension when providing the same elastic force, thereby saving axial installation space and making room for the installation of other components.

[0030] In addition, see Appendix Figure 3 An annular positioning groove 13 is provided on the outer peripheral wall of the end of the sealing sleeve 1 away from the intermediate body 14. The positioning groove 13 is used for clamping and positioning by a tool. During assembly, the tool can assemble the back plate 15, spring, sealing ring 10, graphite ring, shaft seal and other parts to the intermediate body 14 at one time by clamping the sealing sleeve 1, thereby improving assembly efficiency. Preferably, the cross section of the positioning groove 13 is an inverted isosceles trapezoidal structure, that is, the length of the upper base is greater than the lower base.

[0031] In the description of the present application, the description with reference to the terms "present embodiment", "some embodiments", etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradicting each other.

[0032] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A turbocharger sealing structure, comprising a shaft seal, wherein the shaft seal comprises a sealing sleeve (1) sleeved on the outer wall of a turbine shaft (16), one end of the sealing sleeve (1) abutting against a thrust ring (2) on an intermediate body (14), and characterized in that: The sealing ring (3) is also provided with a sealing flange (4) protruding outwardly on the outer wall of the sealing sleeve (1); one end of the sealing ring (3) is in relatively rotatable contact with the side of the sealing flange (4) away from the thrust ring (2); and a plurality of spiral grooves (5) evenly distributed along the circumferential direction are provided on the end surface of the sealing flange (4) and the sealing ring (3); the other end of the sealing ring (3) is slidably and sealingly matched with the back plate (15) along the axial direction, and the other side of the sealing flange (4) is in contact with the thrust bearing (6) on the intermediate body (14); and an elastic element (7) is provided between the end of the sealing ring (3) away from the sealing flange (4) and the back plate (15), so that the sealing ring (3) always has a tendency to move toward the side of the sealing flange (4).

2. The turbocharger sealing structure according to claim 1, characterized in that: A side of the back plate (15) close to the intermediate body (14) is provided with an annular mounting groove (8) in a concave shape, and the cross section of the mounting groove (8) is U-shaped. An end of the sealing ring (3) away from the sealing flange (4) is provided with a mounting boss (9) slidably mounted in the mounting groove (8), and a sealing ring (10) is provided between the inner side wall of the mounting boss (9) and the radial inner side wall of the mounting groove (8).

3. The turbocharger sealing structure according to claim 2, characterized in that: The sealing ring (10) is a star-shaped sealing ring (10), and a sealing groove (11) is concavely arranged on the radial inner wall of the mounting groove (8). The inner end of the star-shaped sealing ring (10) is fitted in the sealing groove (11), and the outer end is sealingly matched with the inner wall of the mounting boss (9).

4. The turbocharger sealing structure according to claim 2 or 3, characterized in that: A positioning step (12) is provided at one end of the sealing ring (3) away from the sealing flange (4) and located radially outside the mounting boss (9), and two ends of the elastic element (7) are respectively in contact with the positioning step (12) and the bottom wall of the mounting groove (8).

5. The turbocharger sealing structure according to claim 4, characterized in that: The elastic element (7) is a wave spring, which is sleeved on the outside of the mounting boss (9), and whose two ends are respectively in contact with the positioning step (12) and the bottom wall of the mounting groove (8).

6. The turbocharger sealing structure according to claim 1, characterized in that: The sealing ring (3) is a graphite ring.

7. The turbocharger sealing structure according to claim 1, characterized in that: An annular positioning groove (13) is provided on the outer peripheral wall of the sealing sleeve (1) at one end away from the intermediate body (14).

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