JPS627851Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a turbocharger, and more particularly to a bearing mechanism for a turbocharger.

Conventionally, a turbocharger shown in FIG. 1 has been known as an effective turbocharger for increasing the engine output of a vehicle. This turbocharger 10 includes a turbine housing 13 having an exhaust inlet 11 and an exhaust outlet 12 for an intake passage for engine combustion gas, a compressor housing 15 having an air inlet 14 for an engine intake passage and a pressurized air outlet, and a compressor housing 15 having an air inlet 14 and a pressurized air outlet for an engine intake passage; a rotating shaft 18 having a turbine wheel 16 located at one end located in the exhaust passage of the turbine housing 13 and a compressor wheel 17 located at the other end located in the intake passage of the compressor housing 15;
It has a housing 20 that supports the bearing via a floating bush 19. A collar 22 is fixed to the small diameter portion of the rotary shaft 18 by a screw via the compressor wheel 17, and the floating bush 19 whose leftward movement is regulated by the thrust bearing 23 of the rotary shaft 18 via the collar 22. The right end on the turbine wheel side faces the large-diameter oil slinger portion 24 of the rotating shaft 18, and also functions as an axial bearing for the rotating shaft 18. 21 is a seal plate. However, in this type of turbocharger 10, the lubricating oil passage forms a part of the lubricating oil passage connecting the lubricating oil inlet 25 and the lubricating oil outlet 26 formed in the housing 20, and connects the outer circumferential side and the inner circumferential side of the floating bush 19. A plurality of oil holes 27 are formed in the floating bush 19 so as to open from the outer circumferential side to the inner circumferential side toward the center of the floating bush 19. Therefore,
The supply of lubricating oil from the outer circumferential side to the inner circumferential side of the floating bush 19 increases as the rotation of the rotating shaft 18 increases, that is, as the rotational speed of the floating bush 19 increases, the centrifugal force acting on the lubricating oil increases. This increased centrifugal force reduces the supply of lubricating oil from the outer circumferential side of the floating bush 19 to the inner circumferential side through the oil hole 27, and the rotational shaft 18 and the floating bush 19
The drawback was that internal burn-in was likely to occur.

Therefore, the present invention is designed to
The purpose is to increase the supply of lubricating oil to the inner circumferential side of the floating bush.

The structure of the present invention is such that the lubricating oil inlet and the lubricating oil outlet provided in the housing are arranged so that the lubricating oil passage connects the outer circumferential side and the inner circumferential side of the floating bushing for the bearing of the rotating shaft in the direction of rotation of the floating bushing. It has an oil hole that is inclined from the inner circumferential side to the outer circumferential side. Therefore, since the oil hole is inclined in the direction of rotation of the floating bush, the rotation of the floating bush actively draws lubricating oil into the oil hole, achieving the intended purpose of increasing the supply of lubricating oil. In addition, there is no need to add a special structure for increasing the supply of lubricating oil, and there is an effect that it is only necessary to tilt the oil hole.

Hereinafter, embodiments of the present invention will be described based on FIGS. 2 and 3. Note that FIGS. 2 and 3 show only the main parts that are different from FIG. 1, which shows a conventional turbocharger.

The floating bush 19 has a plurality of oil holes 30 forming part of a lubricating oil passage connecting the lubricating oil inlet 25 and the lubricating oil outlet 26, and the oil holes 30 are connected to the lubricating oil passages 25a, 25a, and 25a in FIG. 25b. As is clear from FIG. 3, the oil hole 30 extends from the inner circumferential side 32 to the outer circumferential side 31 in the rotational direction A of the floating bush 19 so as to connect the outer circumferential side 31 and the inner circumferential side 32 of the floating bush 19. It is installed at an angle. More specifically, the center O of the floating bush 19
From this, a line a is drawn parallel to the oil hole 30 in Figure 3.
and the angle θ determined by the line c connecting the center O and the center b of the inner peripheral side 32 of the oil hole 30 is 0°<θ≦
The oil holes 30 are each formed at an angle of 90°.

Therefore, in the oil hole 30 formed as described above, lubricating oil is supplied from the outer peripheral side 32 of the floating bush 19 to the inner peripheral side 31 through the oil hole 30 not only by the oil pressure of the lubricating oil itself, but also by the oil pressure of the lubricating oil itself. This is assisted by the winding action caused by the rotation of the floating bush 19. Therefore, even when the floating bush 19 rotates at high speed, the rotating shaft 18
Sufficient lubrication between the floating bush 19 and the floating bush 19 can be guaranteed.
Incidentally, the larger the angle θ is, the more lubricant can be supplied by the drawing action. A passage 33 branching from the left oil hole 30 of the floating bush 19 in FIG. This is a lubricating oil passage between the oil slinger portion 24 of No. 18 and the floating bush 19. An oil hole 35 provided in the center of the floating bush 19 in FIG. 2 is connected to the lubricating oil outlet 26.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional turbocharger.
FIG. 2 is a sectional view of essential parts of the turbocharger of the present invention, and FIG. 3 is a sectional view taken along the line -- in FIG. 10...Turbo charger, 13, 15, 20
...Housing, 16...Turbine wheel, 1
7... Compressor wheel, 18... Rotating shaft,
19...Floating bush, 25...Lubricating oil inlet, 2
6...Lubricating oil outlet, 30...Oil hole.

Claims (1)

[Scope of utility model registration request] a housing; a rotating shaft disposed within the housing and 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; the rotating shaft being rotatably mounted within the housing; The housing has a floating bush for a bearing, a lubricating oil inlet and a lubricating oil outlet respectively provided in the housing, and a lubricating oil passage connecting the inlet and the outlet, and the lubricating oil passage is connected to an outer peripheral side and an inner side of the floating bush. A bearing mechanism for a turbocharger that includes an oil hole that is inclined from the inner circumferential side to the outer circumferential side in the direction of rotation of the floating bushing so as to connect the circumferential sides.