JPH0214971B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing device for a turbocharger.

Conventionally, a turbocharger that is effective in increasing the engine output of a vehicle has a rotating shaft equipped with a turbine wheel located in an exhaust passage at one end and a compressor wheel located in an intake passage at the other end, and a thrust for the rotating shaft. It had a bearing and a thrust bush provided on the rotating shaft between the thrust bearing and the compressor wheel. In order to prevent the lubricating oil transmitted to the thrust bearing from leaking toward the compressor wheel, it is known that a seal plate is provided on the outside of the thrust bush. However, this conventional type has the disadvantage that lubricating oil leaks to the compressor wheel side due to the capillary phenomenon caused by the minute gap between the thrust bush and the seal plate. If there is negative pressure on the side,
This drawback became even more noticeable.

An object of the present invention is to improve the sealing properties of lubricating oil.

The present invention provides at least two annular grooves formed on the outer circumferential surface of a thrust bush provided on a rotating shaft between a compressor wheel and a thrust bearing, and in which a seal ring is disposed; It has a sealing device consisting of at least one annular groove formed on the inner circumferential surface of the seal plate facing the outer circumferential surface, and the gap between the thrust bush and the seal plate can be made large or small by the formation of the annular groove. The compressor has a labyrinth effect and prevents capillary phenomenon by repeating expansion and contraction, and seal rings are disposed within at least two annular grooves to prevent lubricating oil from leaking to the compressor side. The intended purpose can be achieved.

As described above, the present invention provides an annular groove on the outer periphery of the thrust bush and arranges a seal ring therein, and together with the annular groove provided on the inner periphery of the seal plate, prevents capillary phenomenon and improves sealing performance. Compared to mechanical seal devices, etc., which press the seal part with a spring to improve sealing performance, the sliding resistance is not particularly increased, and therefore friction loss can be reduced. This has the effect that the operational response is not particularly impaired. Furthermore, compared to mechanical seals, etc., it has the effect of providing a structure that is cheaper and has better sealing performance.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the drawing, the turbocharger 10 includes a turbine housing 13 having an exhaust inlet 11 and an exhaust outlet 12 for the exhaust passage of engine combustion gases, and an air inlet 14 and a pressurized air outlet 15 for the engine intake passage.
a rotating shaft having a compressor housing 16 located between the compressor housing 16 and a turbine wheel 17 located in the exhaust passage of the turbine housing 13 at one end and a compressor wheel 18 located in the intake passage of the compressor housing 16 at the other end; 19 and a housing 21 supported via a floating bush 20. A thrust plate 23, a thrust spacer 24,
The thrust bushes 25 are arranged and fixed one after the other, as is particularly clear in FIG. Thrust plate 23
A thrust bearing 26 for the rotating shaft 19 is disposed between the thrust bush 25 and the thrust spacer 24 . The floating bush 20, whose leftward movement is restricted by the thrust plate 23, has its right end on the turbine wheel side facing the large diameter portion 27 of the rotating shaft 19, and also functions as an axial bearing for the rotating shaft 19. . A seal plate 29 having an O-ring 28 between it and the intermediate housing 21 is fixed to the outside of the thrust bush 25 . The intermediate housing 21 is formed with an inlet 30 and an outlet 31 for lubricating oil.
oil passages 32, 33, 34 formed in the floating bush 20, oil passage 35 formed in the floating bush 20,
Each part is lubricated through 36.

In particular, in FIG. 2, the passage 33 is a lubricating oil passage 37 formed in the thrust bearing 26,
A thrust plate 23, a thrust spacer 24, a thrust bush 25, and a thrust bearing 26, which are connected to the rotary shaft 19 and rotate together with the rotating shaft 19.
It lubricates the space between. At least two annular grooves 41 and 42 are formed in the outer peripheral surface of the thrust bush 25, in which seal rings 39 and 40 are disposed, respectively. At least one annular groove 43 is formed on the circumferential surface to constitute a sealing device 44 that prevents lubricating oil from leaking to each part of the thrust bearing 26 toward the compressor wheel 18 side. In other words, the annular groove 4
1 and 42 and the annular groove 43, the gap between the thrust bush 25 and the seal plate 29 repeatedly expands and contracts, creating a labyrinth effect, and also prevents capillary phenomenon, thereby improving the seal between the thrust bush 25 and the seal plate 29. You can improve your sexuality. Furthermore, as shown in the second figure, if the left part of the annular groove 43 of the seal plate 29 is configured to partially overlap the outer right end surface of the seal ring 39, the contact area between the seal plate 29 and the seal ring 39 is reduced. is reduced, the seal surface pressure increases, and capillary phenomenon can be further prevented, and the phenomenon of scraping of the working oil entering between the thrust bush 25 and the seal plate 29 into the annular groove 43 can be increased, thereby improving sealing performance. You can improve even further.

The right flange portion 45 of the thrust bush 25 that contacts the thrust bearing 26 is formed with an R portion 47 having a groove portion 46 having a smaller diameter than the left outer peripheral surface and extending in the radial direction along the flange portion 45. Ru. Therefore, the lubricating oil scattered from the clearance between the thrust bush 25, thrust plate 23, and thrust bearing 26 is guided by the centrifugal force to the R portion 47, is urged outward, and is discharged toward the oil outlet 31. be done.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is an enlarged sectional view of the main part of FIG. 1. 10...Turbo charger, 17...Turbine wheel, 18...Compressor wheel, 19
... Rotating shaft, 23 ... Thrust plate, 24 ...
... Thrust spacer, 25 ... Thrust bush, 26 ... Thrust bearing, 29 ... Seal plate, 39, 40 ... Seal ring, 4
1, 42... annular groove, 43... annular groove, 44...
sealing device.

Claims (1)

[Claims] 1. A rotating shaft having a turbine wheel located in the exhaust passage at one end and a compressor wheel located in the intake passage at the other end, a thrust bearing for the rotating shaft, and between the compressor wheel and the thrust bearing. A turbocharger having a thrust bush provided on the rotating shaft and a seal plate disposed outside the thrust bush, wherein the seal ring is formed on the outer peripheral surface of the thrust bush and a seal ring is disposed therein. at least two first annular grooves formed on the inner circumferential surface of the seal plate opposite to the outer circumferential surface of the thrust bush, and the grooves are not on the thrust bearing side of the sealed space between the seal rings. A sealing device for a turbocharger, which includes a sealing device including at least one second annular groove arranged to overlap with the first annular groove, and prevents lubricating oil from leaking to the compressor wheel side from the thrust bearing portion. .