Turbocharger sealing structure with self-cleaning ability

Abstract

The present invention discloses a supercharger sealing structure with self-cleaning ability, which includes an intermediate body and a turbine shaft, and also includes two sealing rings. A middle hole and a self-cleaning sealing air inlet passage are arranged inside the intermediate body. The axes of the middle hole and the turbine shaft are along the front-rear direction. Two installation grooves are arranged at intervals along the axial direction on the turbine shaft; the outer rings of the two sealing rings are both abutted against the middle hole, and the inner rings of the two sealing rings are respectively sleeved on the two installation grooves in a clearance fit manner; the head end of the self-cleaning sealing air inlet passage exposes from the front end of the intermediate body, so that the head end of the self-cleaning sealing air inlet passage is communicated with the outside of the intermediate body; the tail end of the self-cleaning sealing air inlet passage is communicated with the middle hole between the two sealing rings. The present invention can utilize the high-pressure exhaust gas discharged from the engine to ensure the sealing performance and have the self-cleaning ability.

Description

Technical Field

[0001] The present invention relates to a turbocharger, and more particularly to a supercharger sealing structure with self-cleaning ability. Background Art

[0002] With the widespread application of turbocharging technology in gasoline engines, the oil leakage failure at the turbine end of the supercharger has become the focus of after-sales problems. Not only is the after-sales maintenance cost high, but it is also easy to cause high customer complaints. Therefore, a sealing structure with strong sealing ability is needed to limit the external leakage of lubricating oil. In the conventional design of the supercharger, a sealing ring and an oil slinger structure are used for sealing. Limited by machining equipment, materials, machining accuracy, etc., after the supercharger is used for a period of time, the sealing structure is extremely easy to form an oil leakage channel due to wear, resulting in oil leakage at the turbine end of the supercharger, and the lubricating oil enters the engine, causing lubricating oil burning and increased engine fuel consumption. In addition, the sealing ring itself is designed as an open-type sealing ring, and the matching ring groove is also a clearance fit, which cannot ensure that it is always in a sealed state. The traditional solution is to increase the number of sealing rings and oil slingers, reduce the mating clearance, etc. The above measures increase the cost of the supercharger, the manufacturing difficulty and the assembly difficulty. In actual use, the biggest problem is that carbon deposition in the sealing ring groove causes the sealing ring not to be in an ideal sealing position, resulting in serious oil leakage and cannot be solved.

[0003] CN110005477A discloses a hydrostatic sealing structure for a two-stage turbocharger, including a low-pressure stage supercharger and a high-pressure stage supercharger connected thereto. The pressure balance is achieved between the compressor air outlet of the high-pressure stage supercharger and the compressor end of the low-pressure stage supercharger and / or between the compressor air outlet of the high-pressure stage supercharger and the turbine end of the low-pressure stage supercharger through a hydrostatic sealing component. The invention solves the problems in the traditional technology that for the low-pressure stage supercharger, either the compressor end is sealed, resulting in oil leakage at the turbine end, or the turbine end is sealed, resulting in oil leakage at the compressor end; and the contact surface of the single-sided contact sealing component generates friction during operation, which is prone to unevenness, resulting in an increase in wear; and when idling, the low-pressure stage cannot generate supercharged gas and intake resistance and other factors, resulting in the air pressure at the sealing ring being less than the atmospheric pressure, and the additional sealing component cannot continue to store and block the lubricating oil, resulting in frequent oil leakage. Undoubtedly, the technical solution disclosed in the above patent document is a beneficial attempt in the technical field, but it cannot solve the oil leakage and air leakage problems caused by carbon deposition. During the operation of the supercharger, the lubricating oil pressure increases with the increase of the supercharger speed. The hydrostatic seal described therein cannot dynamically adapt to the change of the lubricating oil pressure, and there are disadvantages such as excessive low-speed air pressure or insufficient high-speed air pressure.

[0004] CN210714853U discloses a sealing structure applied to the compression end and turbine end of a turbocharger, including an expansion plate, an intermediate body, a shaft seal, and a sealing ring; one end of the turbine shaft is fixedly connected to the turbine, and the other end thereof passes through the shaft hole of the expansion plate and is connected to the impeller; a thrust bearing is provided between the intermediate body and the expansion plate; one end of the shaft seal is provided with a flange; one end of the flange abuts against the expansion plate, and the other end abuts against the thrust bearing; two sealing ring grooves are formed in the shaft seal; sealing rings are arranged in the sealing ring grooves; the sealing rings are in contact with the expansion plate, and the edges of the side where the sealing rings contract are all rounded corners. By changing the structure and number of the sealing rings, when the sealing rings are installed, due to the force characteristics of the rounded corners, a component force that causes the sealing rings to radially contract will be generated, so that the sealing rings are more likely to contract during the installation process, reducing the possibility of their damage and deformation, thereby improving the sealing effect of the turbocharger, reducing the probability of oil leakage, and having a simple structure, being easy to implement, having good economy, and a high safety factor. Undoubtedly, the technical solution disclosed in the above patent document is a beneficial attempt in the technical field to which it belongs, but it still cannot solve the problems of oil leakage and air leakage caused by carbon deposition. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a supercharger sealing structure with self-cleaning ability, which can utilize the high-pressure exhaust gas discharged from the engine to ensure the sealing performance. At the same time, it can quickly carbonize the accumulated oil and deteriorated lubricating oil by using the high-pressure exhaust gas discharged from the engine, and blow the carbon deposits towards the oil return passage inside the intermediate body or towards the outside of the intermediate body.

[0006] A supercharger sealing structure with self-cleaning ability in the present invention includes an intermediate body and a turbine shaft, and also includes two sealing rings. A middle hole and a self-cleaning seal intake passage are arranged inside the intermediate body. The axes of the middle hole and the turbine shaft are along the front-back direction. Two installation grooves are arranged at intervals along the axial direction on the turbine shaft; the outer rings of the two sealing rings both abut against the middle hole, and the inner rings of the two sealing rings are respectively sleeved on the two installation grooves in a clearance fit manner; the head end of the self-cleaning seal intake passage exposes from the front end of the intermediate body, so that the head end of the self-cleaning seal intake passage is communicated with the outside of the intermediate body; the tail end of the self-cleaning seal intake passage is communicated with the middle hole between the two sealing rings.

[0007] Further, the self-cleaning seal intake passage includes a plurality of first air passages, one second air passage, and a plurality of third air passages. The head ends of the plurality of first air passages are all communicated with the outside of the front end of the intermediate body, and the tail ends of the plurality of first air passages are all communicated with the second air passage; the head ends of the plurality of third air passages are all communicated with the second air passage, and the tail ends of the plurality of third air passages are all communicated with the middle hole between the two sealing rings.

[0008] Further, the tail end positions of the plurality of first airways are respectively offset from the positions of the plurality of third airways.

[0009] Further, the second airway is annular, and the second airway is located within the intermediate body and surrounds the outside of the middle hole.

[0010] Further, the plurality of first airways are all inclined straight airways.

[0011] Further, the plurality of first airways are arranged at intervals along the circumferential direction of the middle hole, and the plurality of first airways are gradually inclined forward radially outward along the middle hole.

[0012] Further, the cross-sections of the first airway, the second airway, and the third airway are each one of a circle, an ellipse, a square, and a regular polygon.

[0013] Further, the cross-sections of the first airway, the second airway, and the third airway are all circular. The cross-sectional diameter Da of the first airway is 3 - 7 mm, the cross-sectional diameter Db of the second airway is 1.2*Da - 1.4*Da, and the cross-sectional diameter Dc of the third airway is 0.5*Da - 0.7*Da.

[0014] Further, the sealing ring is an open-type sealing ring.

[0015] The beneficial effects of the present invention are as follows:

[0016] (1) The present invention can utilize the high-pressure exhaust gas discharged from the engine, so that the front ring wall sealing surface of the front sealing ring tightly abuts against the front groove wall sealing surface of the front mounting groove, and the rear ring wall sealing surface of the rear sealing ring tightly abuts against the rear groove wall sealing surface of the rear mounting groove, thereby ensuring that the two sealing rings always maintain a good sealing state. The lubricating oil can only be retained in the intermediate body, and the high-pressure exhaust gas discharged from the engine cannot enter the intermediate body through the middle hole and the sealing ring, thus ensuring that there is no oil leakage or air leakage at the connection between the intermediate body and the turbine shaft;

[0017] (2) The present invention has a self-cleaning function. When there is accumulated oil, deteriorated lubricating oil, or carbon deposit between the rear ring wall sealing surface and the rear groove wall sealing surface or between the front ring wall sealing surface and the front groove wall sealing surface, it can utilize the high-pressure exhaust gas discharged from the engine to quickly carbonize the accumulated oil and the deteriorated lubricating oil, and blow the carbon deposit towards the oil return passage inside the intermediate body or towards the outside of the intermediate body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the objectives, technical solutions, and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0019] Figure 1 is a schematic structural diagram of the present invention;

[0020] Figure 2 Schematic cross-sectional views at the first air passage and the second air passage of the present invention;

[0021] Figure 3 is Figure 2 partial enlarged view of;

[0022] Figure 4 Schematic cross-sectional views at the second air passage and the third air passage of the present invention;

[0023] Figure 5 is Figure 4 partial enlarged view of.

[0024] The reference signs in the drawings are as follows: 1 - intermediate body, 2 - self-cleaning sealed intake air passage, 21 - first air passage, 22 - second air passage, 23 - third air passage, 3 - turbine shaft, 31 - front side groove wall sealing surface, 32 - rear side groove wall sealing surface, 4 - sealing ring, 41 - front side ring wall sealing surface, 42 - rear side ring wall sealing surface. Detailed Description of the Invention

[0025] The technical solution of the present invention will be described in detail below with reference to the drawings and embodiments.

[0026] As Figures 1 - 5 shown, a supercharger sealing structure with self-cleaning ability in this embodiment includes an intermediate body 1 and a turbine shaft 3, and further includes two sealing rings 4. A middle hole and a self-cleaning sealed intake air passage 2 are provided inside the intermediate body 1. The axes of the middle hole and the turbine shaft 3 are along the front-rear direction, and two mounting grooves are arranged at intervals along the axial direction on the turbine shaft 3; the outer rings of the two sealing rings 4 are both abutted against the middle hole, and the inner rings of the two sealing rings 4 are respectively sleeved on the two mounting grooves in a clearance fit manner; the front end of the self-cleaning sealed intake air passage 2 exposes from the front end of the intermediate body 1, so that the front end of the self-cleaning sealed intake air passage 2 is communicated with the outside of the intermediate body 1; the rear end of the self-cleaning sealed intake air passage 2 is communicated with the middle hole between the two sealing rings 4.

[0027] During use, the front end of the turbine shaft 3 is connected to the supercharger turbine, the rear end of the turbine shaft 3 is connected to the impeller rotating shaft of the supercharger. The high-pressure exhaust gas discharged from the engine causes the supercharger turbine in the turbine chamber to rotate. The rotation of the supercharger turbine can drive the turbine shaft 3 and the impeller rotating shaft of the supercharger to rotate. The rotation of the impeller rotating shaft of the supercharger can realize the compression of the air sent from the air filter pipeline, so that it is pressurized and enters the cylinder.

[0028] Based on the working principle of this supercharger, the high-pressure exhaust gas discharged from the engine will form an airflow with uneven air pressure distribution on the front side of the intermediate body 1 due to the rotation of the supercharger turbine. The front end of the self-cleaning sealed intake passage 2 in this embodiment protrudes from the front end of the intermediate body 1, and the front end of the self-cleaning sealed intake passage 2 is connected to the outside of the intermediate body 1. Therefore, the front end of the self-cleaning sealed intake passage 2 becomes the air inlet. The high-pressure exhaust gas discharged from the engine will enter the self-cleaning sealed intake passage 2 from the front end of the self-cleaning sealed intake passage 2 to form a high-flow-rate airflow. The high-flow-rate airflow flows from the rear end of the self-cleaning sealed intake passage 2 into the middle hole between the two sealing rings 4. At this time, since the sealing ring 4 is an open-type sealing ring, there are gaps between the front and rear sides of the sealing ring 4 and the front and rear sides of the installation groove. The exhaust gas in the middle hole between the two sealing rings 4 will push the front sealing ring 4 forward, so that the front ring wall sealing surface 41 of the front sealing ring 4 tightly abuts against the front groove wall sealing surface 31 of the front installation groove, and the rear ring wall sealing surface 42 of the rear sealing ring 4 tightly abuts against the rear groove wall sealing surface 32 of the rear installation groove, thereby ensuring that the two sealing rings 4 always maintain a good sealing state. The lubricating oil can only be kept in the intermediate body 1, and the high-pressure exhaust gas discharged from the engine cannot enter the intermediate body 1 through the middle hole and the sealing ring 4, thus ensuring that there is no oil leakage or air leakage at the connection between the intermediate body 1 and the turbine shaft 3.

[0029] If there is accumulated oil, deteriorated lubricating oil or carbon deposits between the rear ring wall sealing surface 42 and the rear groove wall sealing surface 32, when the exhaust gas in the middle hole between the two sealing rings 4 pushes the rear sealing ring 4 backward, the accumulated oil, deteriorated lubricating oil or carbon deposits will prevent the rear ring wall sealing surface 42 and the rear groove wall sealing surface 32 from tightly abutting. Since the sealing ring 4 is an open-type sealing ring, there are gaps between the front and rear sides of the sealing ring 4 and the front and rear sides of the installation groove. Also, since there is a gap between the inner ring of the sealing ring 4 and the installation groove, the exhaust gas in the middle hole between the two sealing rings 4 will enter the gap between the inner ring of the sealing ring 4 and the installation groove, then flow to the gap between the rear ring wall sealing surface 42 and the rear groove wall sealing surface 32, and finally flow to the oil return passage on the inner side of the intermediate body 1. Since the high-pressure exhaust gas discharged by the engine during high-load operation can reach up to 900 degrees Celsius, during the above-mentioned flow process, the high-temperature and high-flow-rate airflow formed by the exhaust gas will quickly carbonize the accumulated oil and deteriorated lubricating oil between the rear ring wall sealing surface 42 and the rear groove wall sealing surface 32, and blow the carbon deposits towards the oil return passage on the inner side of the intermediate body 1, realizing the self-cleaning of the rear sealing ring 4 and the installation groove.

[0030] If there is accumulated oil, deteriorated lubricating oil or carbon deposit between the front side ring wall sealing surface 41 and the front side groove wall sealing surface 31, when the exhaust gas in the middle hole between the two sealing rings 4 pushes the front sealing ring 4 forward, the accumulated oil, deteriorated lubricating oil or carbon deposit will prevent the front side ring wall sealing surface 41 from closely abutting against the front side groove wall sealing surface 31. Since the sealing ring 4 is an open-type sealing ring, there are gaps between the front and rear sides of the sealing ring 4 and the front and rear sides of the installation groove. Also, there is a gap between the inner ring of the sealing ring 4 and the installation groove. Therefore, the exhaust gas in the middle hole between the two sealing rings 4 will enter the gap between the inner ring of the sealing ring 4 and the installation groove, then flow to the gap between the front side ring wall sealing surface 41 and the front side groove wall sealing surface 31, and finally flow out of the intermediate body 1 through the middle hole. Since the high-pressure exhaust gas discharged by the engine during high-load operation can reach up to 900 degrees Celsius, during the above-mentioned flow process, the high-temperature and high-velocity airflow formed by the exhaust gas will quickly carbonize the accumulated oil and deteriorated lubricating oil between the front side ring wall sealing surface 41 and the front side groove wall sealing surface 31, and blow the carbon deposit out of the intermediate body 1, realizing self-cleaning of the front sealing ring 4 and the installation groove.

[0031] In this embodiment, the self-cleaning sealed air intake passage 2 includes a plurality of first air passages 21, a second air passage 22, and a plurality of third air passages 23. The heads of the plurality of first air passages 21 are all connected to the outside of the front end of the intermediate body 1, and the tails of the plurality of first air passages 21 are all connected to the second air passage 22; the heads of the plurality of third air passages 23 are all connected to the second air passage 22, and the tails of the plurality of third air passages 23 are all connected to the middle hole between the two sealing rings 4. The first air passage 21 mainly functions as an air intake, and the plurality of first air passages 21 respectively introduce engine exhaust gas into the second air passage 22; the second air passage 22 mainly functions to stabilize the pressure. Since the air pressure distribution on the front side of the intermediate body 1 is uneven, the air pressure and flow rate of the airflow introduced by the first air passage 21 may vary greatly. By stabilizing the pressure through the second air passage 22, the air pressure difference and flow rate difference of the airflow flowing into each third air passage 23 can be reduced; the third air passage 23 mainly functions to introduce the exhaust gas into the middle hole between the two sealing rings 4.

[0032] In this embodiment, the positions of the tails of the plurality of first air passages 21 are respectively offset from the positions of the plurality of third air passages 23. The position mentioned here refers to the position in the circumferential direction. The offset position can ensure that the exhaust gas at the tail of the first air passage 21 will enter the third air passage 23 after the pressure is stabilized in the second air passage 22.

[0033] In this embodiment, the second air passage 22 is annular, and the second air passage 22 is located inside the intermediate body 1 and surrounds the middle hole.

[0034] In this embodiment, the plurality of first air passages 21 are all inclined straight air passages. The inclined straight air passages are more conducive to the flow of exhaust gas and are beneficial to increasing the intake air flow rate.

[0035] In this embodiment, the plurality of first air passages 21 are arranged at intervals along the circumferential direction of the middle hole, and the plurality of first air passages 21 are gradually inclined forward radially outward of the middle hole. This setting makes the position of the head end of the first air passage 21 far from the middle hole, and the air pressure of the air flow on the front side of the intermediate body 1 due to the rotation of the supercharger turbine is relatively high here, further increasing the intake air flow rate.

[0036] In this embodiment, the cross-sections of the first air passage 21, the second air passage 22 and the third air passage 23 are each one of a circle, an ellipse, a square and a regular polygon. Preferably, the cross-sections of the first air passage 21, the second air passage 22 and the third air passage 23 are all circular. The cross-sectional diameter Da of the first air passage 21 is 3-7 mm, the cross-sectional diameter Db of the second air passage 22 is 1.2*Da - 1.4*Da, and the cross-sectional diameter Dc of the third air passage 23 is 0.5*Da - 0.7*Da. For example, Da = 5 mm, Db = 1.3*Da = 6.5 mm, Dc = 0.6*Da = 3 mm. The relatively large cross-section of the second air passage 22 is beneficial to pressure stabilization.

[0037] In this embodiment, the sealing ring 4 is an open-type sealing ring.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A supercharger sealing structure with self-cleaning ability, comprising an intermediate body (1) and a turbine shaft (3), characterized in that: It also includes two sealing rings (4). A middle hole and a self-cleaning sealed air inlet passage (2) are provided inside the intermediate body (1). The axes of the middle hole and the turbine shaft (3) are in the front-rear direction. Two mounting grooves are arranged on the turbine shaft (3) at intervals along the axial direction. The outer rings of the two sealing rings (4) are both abutted against the middle hole, and the inner rings of the two sealing rings (4) are respectively sleeved on the two mounting grooves in a clearance fit manner. The head end of the self-cleaning sealed air inlet passage (2) exposes from the front end of the intermediate body (1) so that the head end of the self-cleaning sealed air inlet passage (2) is communicated with the outside of the intermediate body (1). The tail end of the self-cleaning sealed air inlet passage (2) is communicated with the middle hole between the two sealing rings (4). The gas in the self-cleaning sealed air inlet passage (2) is the high-pressure waste gas discharged from the engine. The high-pressure waste gas quickly carbonizes the engine oil and the deteriorated lubricating oil, and blows the carbon deposits towards the oil return passage inside the intermediate body (1) or towards the outside of the intermediate body (1).

2. The supercharger sealing structure with self-cleaning ability according to claim 1, characterized in that: The self-cleaning sealed air inlet passage (2) includes a plurality of first air passages (21), a second air passage (22) and a plurality of third air passages (23). The head ends of the plurality of first air passages (21) are all communicated with the outside of the front end of the intermediate body (1), and the tail ends of the plurality of first air passages (21) are all communicated with the second air passage (22). The head ends of the plurality of third air passages (23) are all communicated with the second air passage (22), and the tail ends of the plurality of third air passages (23) are all communicated with the middle hole between the two sealing rings (4).

3. The supercharger sealing structure with self-cleaning ability according to claim 2, characterized in that: The positions of the tail ends of the plurality of first air passages (21) are staggered from the positions of the plurality of third air passages (23).

4. The supercharger sealing structure with self-cleaning ability according to claim 2, characterized in that: The second air passage (22) is annular. The second air passage (22) is located inside the intermediate body (1) and surrounds the outside of the middle hole.

5. The supercharger sealing structure with self-cleaning ability according to claim 2, characterized in that: The plurality of first air passages (21) are all inclined straight air passages.

6. The supercharger sealing structure with self-cleaning ability according to claim 5, characterized in that: The plurality of first air passages (21) are arranged at intervals along the circumferential direction of the middle hole, and the plurality of first air passages (21) gradually incline forward radially outward along the middle hole.

7. The supercharger sealing structure with self-cleaning ability according to claim 2, characterized in that: The cross-sections of the first air passage (21), the second air passage (22) and the third air passage (23) are each one of a circle, an ellipse, a square and a regular polygon.

8. The supercharger sealing structure with self-cleaning ability according to claim 7, characterized in that: The cross-sections of the first air passage (21), the second air passage (22) and the third air passage (23) are all circular. The cross-section diameter Da of the first air passage (21) is 3-7 mm, the cross-section diameter Db of the second air passage (22) is 1.2*Da - 1.4*Da, and the cross-section diameter Dc of the third air passage (23) is 0.5*Da - 0.7*Da.

9. The supercharger sealing structure with self-cleaning ability according to any one of claims 1-8, characterized in that: The sealing ring (4) is an open-type sealing ring.

Images