Turbine end oil seal structure of mixed flow turbocharger

Abstract

The utility model discloses a vortex end oil seal structure of a mixed flow turbocharger. Leakage of vortex end lubricating oil is reduced. Comprising a bearing shell, a bearing seat and a turbine shaft, the turbine shaft is installed in the bearing seat through a bearing, the bearing seat is fixedly installed in the bearing shell, an oil return cavity is formed between the bearing shell and the front end of the bearing seat, a second turbine end oil seal structure extending forwards is arranged on the front end face of the bearing seat, and the front end of the turbine shaft is in a step shaft shape. A gap is reserved between the second vortex end oil seal structure and the turbine shaft step face, and a first oil blocking cavity is defined by the second vortex end oil seal structure, the turbine shaft and the bearing. A bearing shell oil seal structure is arranged at the position, corresponding to the large-diameter section of the front end of the turbine shaft, of the bearing shell, a first vortex end oil seal structure extending in the radial direction is arranged on the front end face of the bearing shell, a second oil blocking cavity is defined by the first vortex end oil seal structure, the outer surface of the second vortex end oil seal structure and the bearing shell oil seal structure, and the oil return cavity is communicated with the outer end of the second oil blocking cavity.

Description

Technical Field

[0001] The utility model relates to the technical field of turbochargers, in particular to a vortex end oil seal structure of a mixed flow turbocharger. Background Art

[0002] At present, the lubricating oil of turbocharged diesel engines will leak from the matching surface between the bearing shell of the turbocharger and the turbine into the turbine shell, resulting in oil leakage at the turbine end. The main reason is that the current sealing structure is relatively simple. When the turbocharger is running at high speed, the lubricating oil near the turbine end is thrown up by the turbine shaft. The thrown up lubricating oil is not strictly blocked, and then leaks through the matching gap between the bearing shell and the turbine shaft. Oil leakage at the turbine end will cause dry friction between the turbine shaft and the floating bearing, causing excessive temperature to damage the turbine shaft, floating bearing and other rotating parts. In severe cases, it will affect the lubrication of the diesel engine's rotating parts and cause diesel engine failure. Utility Model Content

[0003] The utility model aims to overcome the deficiencies of the prior art and provide a mixed-flow turbocharger vortex end oil seal structure to reduce the leakage of vortex end lubricating oil.

[0004] The purpose of the utility model is achieved in this way:

[0005] A mixed flow turbocharger turbine end oil seal structure comprises a bearing shell, a bearing seat, and a turbine shaft. The turbine shaft is installed in the bearing seat through a bearing, and the bearing seat is fixedly installed in the bearing shell.

[0006] An oil return chamber is provided between the front end of the bearing housing and the bearing seat, a second vortex end oil seal structure extending forward is provided on the front end surface of the bearing seat, the front end of the turbine shaft is in the shape of a stepped shaft, a gap is left between the second vortex end oil seal structure and the stepped surface of the turbine shaft, and a first oil retaining chamber is enclosed between the second vortex end oil seal structure, the turbine shaft and the bearing;

[0007] A bearing shell oil seal structure is provided at the position of the bearing shell corresponding to the large diameter section at the front end of the turbine shaft, and a radially extending first vortex end oil seal structure is provided on the front end surface of the bearing shell. The first vortex end oil seal structure, the outer surface of the second vortex end oil seal structure, and the bearing shell oil seal structure enclose a second oil baffle chamber, and the return oil chamber is connected to the outer end of the second oil baffle chamber.

[0008] Preferably, a plurality of grooves are respectively formed on the inner surface and the outer surface of the second turbine end oil seal structure along the circumferential direction.

[0009] Preferably, the groove on the inner surface of the second turbine end oil seal structure gradually deepens from back to front.

[0010] Preferably, the first vortex end oil seal structure and the second vortex end oil seal structure are formed on the bearing seat.

[0011] Due to the adoption of the above technical solution, the utility model has the following beneficial effects:

[0012] The design of the sealing structure forms two oil retaining chambers, which constitute two vortex end oil seals. The multi-layer oil seals greatly reduce the leakage of the vortex end lubricating oil.

[0013] The integrated structure of the turbine end oil seal not only reduces costs, but also reduces the difficulty of processing and assembly, thereby enhancing its practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the structure of the utility model;

[0015] Figure 2 Schematic diagram of the structure of the bearing seat;

[0016] Figure 3 Schematic diagram of the structure of the oil retaining chamber.

[0017] Reference numerals

[0018] In the accompanying drawings, 1 is a bearing shell, 2 is a bearing seat, 3 is a turbine shaft, 4 is a turbine, 1-a is an oil return chamber, 1-b is a bearing shell oil seal structure, 2-a is a first turbine end oil seal structure, and 2-b is a second turbine end oil seal structure. DETAILED DESCRIPTION

[0019] See also Figure 1-Figure 3 , is an embodiment of a mixed-flow turbocharger turbine end oil seal structure, comprising a bearing shell 1, a bearing seat 2, and a turbine shaft 3. The turbine shaft 3 is installed in the bearing seat 2 through a bearing, and the bearing seat 2 is fixedly installed in the bearing shell 1.

[0020] The first oil seal: an oil return chamber 1-a is provided between the front ends of the bearing housing 1 and the bearing seat 2, a second vortex end oil seal structure 2-b extending forward is provided on the front end surface of the bearing seat 2, the front end of the turbine shaft 3 is in the shape of a stepped shaft, a gap is left between the second vortex end oil seal structure 2-b and the stepped surface of the turbine shaft 3, and the second vortex end oil seal structure 2-b, the turbine shaft 3 and the bearing form a first oil retaining chamber A. A bearing housing oil return chamber is also provided in the bearing housing 1.

[0021] The second oil seal: The bearing shell 1 is provided with a bearing shell oil seal structure 1-b at the portion corresponding to the front large diameter section of the turbine shaft 3, and the front end surface of the bearing seat 2 is provided with a radially extending first vortex end oil seal structure 2-a. The first vortex end oil seal structure 2-a, the outer surface of the second vortex end oil seal structure 2-b, and the bearing shell oil seal structure 1-b enclose the second oil retaining cavity B, and the oil return cavity 1-a is connected to the outer end of the second oil retaining cavity B. In this embodiment, because the first vortex end oil seal structure 2-a blocks the lubricating oil on the left, it also belongs to the second oil retaining cavity B (the dotted part in the B block diagram in the figure).

[0022] The first oil seal and the second oil seal are used together to reduce the risk of oil leakage at the vortex end. The first vortex end oil seal structure 2-a and the second vortex end oil seal structure 2-b are formed on the bearing seat 2. This can reduce costs and reduce the difficulty of processing and assembly.

[0023] The specific process is as follows:

[0024] Step 1: Lubricating oil is thrown up

[0025] When the turbocharger runs at high speed, the lubricating oil will be thrown up, part of which enters the oil return chamber along the bearing shell, part of which enters the oil return chamber along the bearing seat, and part of which leaks through the matching surface of the bearing shell 1 and the turbine shaft 3.

[0026] Step 2: First oil seal

[0027] The lubricating oil thrown up by the turbine shaft is blocked by the design of the second turbine end oil seal structure 2-b. Design points:

[0028] 1. By extending the surface of the bearing seat, the right side of the second vortex end oil seal structure is as close to the step surface of the turbine shaft as possible, so as to block the lubricating oil in the first oil blocking cavity A formed by the second vortex end oil seal structure and the turbine shaft to the maximum extent. The blocked lubricating oil returns to the main shaft for lubrication of the main shaft, which enhances the lubricating ability of the lubricating oil on the main shaft to a certain extent;

[0029] 2. Grooves of a certain width are respectively provided on the upper and lower sides of the second vortex end oil seal structure 2-b. In this embodiment, two grooves are provided on the upper side of the second vortex end oil seal structure and three grooves are provided on the lower side. The grooves provided on the lower side of the second vortex end oil seal structure are characterized in that the groove depth gradually increases from left to right. The main purpose of the design is to increase the ability to seal the lubricating oil.

[0030] Step 3: Second oil seal

[0031] The lubricating oil thrown up by the turbine shaft 3 passes through the first oil seal and then enters the second oil seal formed by the outer surface of the first turbine end oil seal structure 2-a, the second turbine end oil seal structure 2-b and the bearing housing oil seal structure 1-b. Design points:

[0032] The bearing housing oil seal structure 1-b and the raised first turbine end oil seal structure 2-a form a second oil baffle chamber B. The bearing housing oil seal structure 1-b can prevent the lubricating oil from directly entering the mating surface between the bearing housing and the turbine shaft and causing leakage. The first turbine end oil seal structure 2-a can block the lubricating oil thrown up by the turbine shaft 3 on its left side, and allow the lubricating oil to flow into the return oil chamber 1-a along the surface of the bearing seat. The lubricating oil entering the second oil baffle chamber B will enter the return oil chamber 1-a along the groove opened on the second turbine end oil seal structure and the 1-b bearing housing oil seal structure, and finally flow into the turbine shaft, thereby enhancing the lubrication ability of the lubricating oil on the main shaft.

[0033] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the utility model.

Claims

1. A mixed flow turbocharger turbine end oil seal structure, comprising a bearing shell, a bearing seat, and a turbine shaft, wherein the turbine shaft is installed in the bearing seat through a bearing, and the bearing seat is fixedly installed in the bearing shell, characterized in that: An oil return chamber is provided between the front end of the bearing housing and the bearing seat, a second vortex end oil seal structure extending forward is provided on the front end surface of the bearing seat, the front end of the turbine shaft is in the shape of a stepped shaft, a gap is left between the second vortex end oil seal structure and the stepped surface of the turbine shaft, and a first oil retaining chamber is enclosed between the second vortex end oil seal structure, the turbine shaft and the bearing; A bearing shell oil seal structure is provided at the position of the bearing shell corresponding to the large diameter section at the front end of the turbine shaft, and a radially extending first vortex end oil seal structure is provided on the front end surface of the bearing shell. The first vortex end oil seal structure, the outer surface of the second vortex end oil seal structure, and the bearing shell oil seal structure enclose a second oil baffle chamber, and the return oil chamber is connected to the outer end of the second oil baffle chamber.

2. The mixed flow turbocharger turbine end oil seal structure according to claim 1, characterized in that: A plurality of grooves are respectively formed on the inner surface and the outer surface of the second vortex end oil seal structure along the circumferential direction.

3. The mixed flow turbocharger turbine end oil seal structure according to claim 2, characterized in that: The groove on the inner surface of the second turbine end oil seal structure gradually deepens from back to front.

4. The mixed flow turbocharger turbine end oil seal structure according to claim 1, characterized in that: The first vortex end oil seal structure and the second vortex end oil seal structure are formed on the bearing seat.

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