JPS59119026A - Seal device for turbo charger - Google Patents

Abstract

PURPOSE:To achieve a labyrinth effect so that the capillarity may be prevented to prevent leaks of lubrication oil to the compressor side by causing a clearance between a thrust bushing and a seal plate to repeat expansion and contraction by forming an annular groove. CONSTITUTION:A passage 33 is connected to lubrication oil passages 37, 38 which are formed in a thrust bearing 26 to lubricate the interface of thrust plate 23 which rotate in unison with a rotor shaft 19, thrust spacer 24, thrust bushing 25 and thrust bearing 26. Two annular grooves 41, 42 in which seal rings 39, 40 are disposed are formed in the outer circumference of the thrust bushing 25, and an annular groove 43 is formed in the inner circumference of the seal plate 29 to prevent the lubrication oil for various parts of the thrust bearing 26 from leaking to the compressor wheel side 18.

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 turbine wheel located in an exhaust passage at one end and a turbine wheel located in an exhaust passage at one end. A rotary shaft having a compressor wheel located in the intake passage at the other end, a thrust bearing for the rotary shaft, and a thrust bush provided on the rotary shaft between the thrust bearing and the compressor wheel. Ta. In order to prevent lubricating oil from leaking to the compressor wheel side, which would otherwise be transmitted to the thrust bearing cylinder, a seal plate is known to be disposed on the outside of the thrust bush. However, this conventional type has the disadvantage that the lubricating oil leaks to the compressor wheel side due to the capillary phenomenon caused by the minute gap between the fast bushing and the seal plate, especially when the compressor wheel side becomes negative pressure. This drawback was even more pronounced.

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 peripheral surface of a thrust bush provided on a rotating shaft between a compressor wheel and a thrust bearing cylinder, and in which a seal cylinder is arranged; It has a sealing device consisting of at least five annular grooves formed on the inner circumferential surface of the seal plate facing the outer circumferential surface of the thrust bush, and one groove is formed between the thrust bush and the seal plate. By forming the annular grooves, large and small (expansion, contraction) are created, which creates a labyrinth effect and prevents capillary phenomenon, and seal cylinders are disposed within at least two annular grooves. Thus, the desired purpose of preventing leakage of oil to the compressor side can be achieved.

As described above, the present invention provides an annular groove on the outside I8 of the thrust bush, and in combination with an annular groove provided on the inner periphery of the seal plate, prevents capillary phenomenon. Since the sealing properties are the same as above,
Seal f! Compared to mechanical seal devices, etc., which apply pressure to the IfS using a splinter to improve sealing performance, the sliding resistance does not particularly increase, and therefore the operational response is not particularly affected by the reduction in friction loss. Compared to oZ'l'L mechanical seals, etc., which have the advantage that they do not leak, the structure is cheaper and has better sealing properties.

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 18 having an exhaust port 11 and an exhaust outlet 12 for an exhaust passage for engine combustion gas, and a combustor housing having an air port 14 and a pressurized air outlet 152 for the engine intake oil passage. a turbine wheel 17 located between them, 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 combustor housing 16 at the other end. It has a housing 21 which is supported via a shaft 19 and a floating bush 20. A thrust plate 2B is mounted on the small diameter portion of the rotating shaft 19 by a screw 22 via the compressor wheel 18.
Thrust spacer 24° Thrust bush 25 is sequentially disposed and fixed between thrust plate 28 and thrust bush 25, as is particularly clear in FIG. A thrust bearing 26 for use is arranged &E'n. The floating bush 20, whose leftward movement is restricted by the thrust plate 28, has its right end on the turbine wheel side facing roundly with the large diameter 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 is fixed between the thrust bush 25 and the intermediate housing 21 on the outside thereof. The intermediate housing 21 is
Inlet 80 for lubricating oil. An outlet 81 is formed and a passage 82, 88, 84 for oil is formed in the housing 21.
．． Each part is lubricated through oil passages 85 and 86 formed in the floating bush 20.

In particular, in FIG. 2, a passageway 88 is formed in the thrust bearing 26! Connected to lubricating oil path d7゜88 8
Thrust plate 2 rotating together with γL1 rotating shaft 19
8. Sufst spacer 24. Thrust bush 25 and
It lubricates between the thrust bearings 26. The seal cylinder 8 is attached to the outer peripheral surface of the thrust bush 25.
9.4 At least two annular grooves 41 in which the IO is disposed.
At least one annular groove 48 is formed on the inner circumferential surface of the seal plate 29, which is 1'EIIT to the outer circumferential surface of this fast bushing 25, to supply lubricating oil to each part of the thrust bearing 26. Is it leaking to the compressor wheel 18 side? ! A sealing device 44 is configured to prevent a'an from occurring. That is, due to the formation of the annular grooves 41, 42 and 48, the gap between the thrust bushing 25 and the seal plate 29 expands.

The repeated contraction creates a labyrinth effect, and since capillarity can be prevented, the sealing performance between the two can be improved. Furthermore, as shown in the second diagram, the seal plate 2
If the left side -i of the annular groove 48 of No. 9 is configured to partially overlap the right end surface of the outer periphery of the seal cylinder 89, the contact area between the seal plate 29 and the seal ring 89 becomes small. The sealing surface pressure is increased, further preventing capillary phenomenon, and the thrust bushing 25 and sealing plate 29
The phenomenon of scraping of the working oil entering the annular groove 48 between the grooves 48 and 48 is increased, and the sealing performance is improved as above.

Thrust bush 2 in contact with the thrust bearing cylinder 26
On the right flange portion 45 of No. 5, an eight portion 47 is formed which has a groove portion 46 having a smaller diameter than the left outer circumferential surface and extends in the radial direction along the flange portion 45. Therefore, the thrust bush 25, thrust plate 28, thrust bearing 2
Scattered from 6fijl clearance 81. The lubricating oil is guided to the 8 part 47 by centrifugal force and is urged outward 2n.
, and is discharged toward the oil outlet 81.

[Brief explanation of drawings]

FIG. 1 is a T sectional view showing an embodiment of the invention, and second □□□ is an enlarged sectional view of the main part of FIG. 1. 10...Turbocharger, 17, --Turbine wheel, 18...Compressor wheel, 19...
Rotating shaft, 2s... Thrust play), 24... Thrust spacer, 25... Thrust bush, 26...
・Thrust bearing, 29...Seal plate, 8
9.40... Seal ring, 41.42... Annular R
143...Annular groove, 44...Seal salt manufacturing patent applicant Aisin Seiki Co., Ltd. Representative Reio Nakai No. 1-1 Figure 2

Claims (1)

[Claims] a rotating shaft having a turbine wheel located in an exhaust passage and a compressor wheel located in an intake passage at the other end; a thrust bearing for the rotating shaft; the compressor wheel; a thrust bush provided on the rotating shaft;
In the turbocharger having a seal plate disposed on the outside of the thrust bush, (1) at least two annular grooves formed on the outer circumferential surface of the thrust bush in which the seal cylinder is disposed; The sealing device includes at least one annular groove formed on the inner circumferential surface of the seal plate 11 facing the outer circumferential surface of the thrust bush, A turbocharger seal system that prevents leakage to the compressor wheel side.