JPS6032937A - Supercharger - Google Patents

Abstract

PURPOSE:To prevent the occurrence of cracks on walls forming a cooling water pipeline and a cooling water passage of a bearing housing and prevent the abrasion of a radial metal and the seiqure deterioration of lubricating oil by providing a heat insulating air chamber from the cooling water passage to the turbine case side in the bearing housing. CONSTITUTION:Heat is transmitted from a high-temperature turbine case 1 by radiation and conductance, and the side end section of a turbine case 1 of a bearing housing 7 becomes about 300-500 deg.C, however the temperature of the wall between a cooling water passage 12 and an air chamber 18 is decreased to about 150-250 deg.C due to the air chamber 18. Therefore, trouble such as the occurrence of cracks on the wall 24 portion of the bearing housing 7 because of a too large difference in temperature or the boiling of the cooling water in the cooling water passage 12 can be eliminated. In addition, the abrasion of a radial metal 6, the permanent set in fatigue of a shaft seal unit 9, and the deterioration of lubricating oil can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a supercharger having a completely improved cooling structure for a bearing portion in a bearing housing.

[Background of the invention]

A conventional supercharger as disclosed in Japanese Unexamined Patent Publication No. 57-2 (1518) will be explained with reference to FIG. 1. FIG. 1 shows a sectional view,
1 is an exhaust manifold (not shown) of an internal combustion engine; K is a connected turbine case; 2 is a scroll passage provided in the turbine case 1 and introduces exhaust gas; 3 is a turbine impeller rotationally driven by the exhaust gas; turbine shaft 4
is fixed. 5 is a compressor impeller fixed to the turbine shaft 4. 6 is a radial metal that supports the turbine '1 Iift 4 in the radial direction in rotational alignment, and 7 is a bearing no. 7 having a bearing portion that supports the radial metal 6.
It has been identified in the turbine case l in the simulation. Reference numeral 8 denotes a column oil passage that supplies lubricating oil discharged from the engine's oil bong (not shown) to the radial metal 6; 9 denotes a shaft sealing device that prevents lubricating oil from leaking into the scroll passage 2; IIH
A lubricating oil outlet for discharging the supplied lubricating oil, which communicates with the oil sump 0 (shown) of the engine, is a heat receiving wall.

In the above structure, when the engine is operating, 1.6 (10C
Since the exhaust gas having a high temperature of ~c+ooc and g is introduced into the scroll passage 2 and the turbine impeller 3 is driven to rotate, the turbine case 1 and the turbine blades 4r+ and -3 also reach a high temperature of 500C to 800C. Therefore, the bearing housing 7 adjacent to the turbine case 1 also becomes high in temperature due to transmission or radiation. However, since lubricating oil is continuously supplied from lubricating oil extract 11138, radial metal 6
The lubricating oil temperature is approximately 120tZ', and the shaft sealing device 9 is also cooled to approximately 150C to 230C.

If the extension/opening suddenly stops, the engine stops and the inflow of exhaust gas and lubricating oil stops.

Therefore, since cooling by lubricating oil is not performed, the temperatures of the bearing housing 7, radial metal 6, and shaft sealing device 9 increase due to heat transmitted by conduction or radiation from the high-temperature turbine case 1.

The temperature rise in each part peaks after 3 to 5 minutes, as shown in the shaft seal placement part temperature curve A1 and radial metal part temperature curve B in Figure 2, where the horizontal axis represents time and the vertical axis represents temperature. and then declines.

The temperature rise at this time causes wear of the radial metal 6, seizure of the lubricating oil, and so-called failure of the shaft sealing device 9! 1ll (the tension of the piston ring is attenuated), etc.

In order to prevent the temperature of the bearing part from increasing when the engine suddenly stops, a water-cooled bearing has been put into practical use, and this will be explained with reference to FIG.

FIG. 3 shows a sectional view of the supercharger, in which a cooling water passage 12 is provided on the turbine case 1 side in the bearing housing 7, and the cooling water population 13 and cooling water outlet 14 of the cooling water passage 12 are as shown in FIG. 4. It is communicated with the radiator 15 as shown in FIG. In FIG. 4, 16 is a water pump, 17 is an upper tank of the radiator 15, 19 is an exhaust manifold, 2
0 is a checkerboard, 21 is an oil pump, and 22 is an oil reservoir.

In FIG. 4, the cooling water that is guided from the discharge port of the water pump 16 to the cooling water passage 12 via the cooling water port 13 and cools the bearing housing 7 is returned to the radiator 15 from the cooling water outlet 14, and then flows into the turbine. The internal temperature of case 1 is efficiently cooled to l (1 (l U~230C).
This solves problems such as wear of the shaft, seizure of lubricating oil, and wear of the shaft sealing device 9.

However, near the wall 24 on the turbine case 1 side of the cooling water passage 12 of the bearing housing 7 in Fig. 3, the temperature difference between the outside and the inside becomes large, and the cooling water in the cooling water passage wJ12 boils, causing cracks in the piping. In addition, there were problems such as cracks in the bearing housing 7. Furthermore, if water gets mixed into the lubricating oil due to cracks, the lubricating ability will be extremely degraded, resulting in damage to not only the supercharger but also the engine.

[Purpose of the invention]

The present invention was made in view of the above situation, and is designed to provide cooling water piping and! The object of the present invention is to provide a supercharger that can prevent the occurrence of cracks in the wall forming the cooling water passage of the WIl receiver housing, and prevent wear of the radial metal, seizing deterioration of the lubricating oil, and fatigue of the shaft side device. Hang out with things.

[Synopsis of the invention]

The supercharger of the present invention includes: a turbine impeller installed in a turbine case and driven by exhaust gas of an internal combustion engine; a compressed air impeller fixed to a turbine shaft of the turbine impeller for pumping air to the engine; Bearing of the above turbine shaft +
? B is completely built-in, has a lubricating oil passage, and is provided with a bearing housing equipped with a cooling Narcissus FiS on the inside side of the turbine, and a complete air chamber for insulation is provided in the bearing housing from the cooling water passage to the turbine case side. It has been established.

[Embodiments of the invention]

Hereinafter, the supercharging of the present invention will be explained using examples and the same parts as the conventional parts (r
i The same reference numerals indicate the same parts, and the explanation of the structure of the same parts will be omitted and will be explained with reference to FIG. Reference numeral 18 denotes an air chamber, which is provided inside the bearing housing 7 and closer to the turbine case 1 than the cooling water j+1+ path 12 for heat insulation.

When the engine 20 is in operation, as shown in FIG. 4, high-temperature exhaust gas of 600 to 900 C from the exhaust manifold 19 is sent to the turbine case l and rotationally drives the turbine impeller 3, thereby driving the compression rock blade east 5. engine 2
Pressure feed within 0. At this time, the temperature of the turbine case l is also as high as 500C to 800C. On the other hand, the lubricating oil discharged from the oil pump 21 of the engine 20 is supplied to the lubricating oil passage 8, lubricates and cools the radial metal 6, and then returns to the oil reservoir 22 of the engine 2o through the lubricating oil outlet 11. Further, the cooling water that has been cooled in the radiator 15 is pressurized by the water pump 16 and is supplied to the engine 20 in large quantities, but a part of it is introduced into the bearing housing 7 from the cooling water port 13 of the bearing housing 7. After cooling the inside of the bearing housing 7 while passing through the cooling water passage 12, the cooling water returns from the cooling water outlet 14 to the upper tank 17 of the radiator 15 together with the cooling water returned from the engine 20.

At this time, heat is transferred from the high-temperature turbine case l by radiation and heat transfer, and the end of the bearing housing 7 on the turbine case l side has a temperature of 300C to 500C. The temperature of the wall between the air chamber 18 and the air chamber 18 has dropped to 150C to 250C. Therefore, problems such as cracks occurring in the wall 24 portion of the bearing housing 7 or boiling of the cooling water in the cooling water passage 12 due to a large temperature difference can be eliminated. Also, radial metal 6
wear, wear of the shaft seal device 9, deterioration of the lubricating oil, etc. are prevented, and these preventive effects are further promoted by natural convection that occurs when the cooling water becomes high temperature due to heat transfer after the engine 20 is stopped. I can do it.

In this way, in the turbocharger of this embodiment, if the bearing housing is cooled by providing only the cooling water passage, cooling can be performed efficiently, but as mentioned in Part 2 above, the temperature inside and outside of the turbine case wall increases. Because of the large difference, the cooling water could boil and damage the piping, or cause cracks in the walls of the bearings and housings, so we installed an insulating air chamber in conjunction with the conventional method, and cooled using only the cooling water. This prevents large temperature differences from occurring on the walls of the cooling water passages, thereby reducing the need for straining the materials used to cool the bearing housing, thereby preventing cracks in the bearing housing and piping, and reducing wear on the radial metal. This can prevent the shaft seal from becoming worn out and the lubricating oil from deteriorating.

〔Effect of the invention〕

As described above, the supercharger of the present invention prevents the occurrence of cracks in the cooling water piping and the wall that forms the entire cooling water passage of the bearing housing, prevents the occurrence of cracks in the walls that form the cooling water pipes and the cooling water passages of the bearing housing, prevents the occurrence of cracks in the walls that form the cooling water pipes and the cooling water passages of the bearing housing, prevents the occurrence of cracks in the walls that form the cooling water pipes and the cooling water passages of the bearing housing, prevents the occurrence of cracks in the walls that form the cooling water pipes and the cooling water passages of the bearing housing, prevents the occurrence of cracks in the walls that form the cooling water pipes and the cooling water passages in the bearing housing, and prevents the occurrence of cracks in the walls that form the cooling water pipes and the cooling water passages in the bearing housing. This has the effect of preventing sagging.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional turbocharger, and Figure 2 is a cross-sectional view of a conventional turbocharger.
Fig. 3 is a cross-sectional view of a conventional turbocharger with measures taken to prevent temperature rise in the shaft seal of the engine shown in Fig. 1, and Fig. 4 is the turbocharger piping diagram in Figure 3,
FIG. 5 is a sectional view of an embodiment of the supercharger of the present invention.

Claims (1)

[Claims] 1. A turbine impeller installed in a turbine case and driven by the exhaust gas of the internal combustion engine, a compressor impeller fixed to the turbine shaft of the turbine impeller and pressurizing air to the engine, and an M of the turbine shaft. A bearing housing having a built-in receiving portion, a lubricating oil passage, and a cooling water passage inside on the turbine case side, wherein the bearing housing is provided with heat insulation from the cooling water passage to the turbine case side. A supercharger characterized by having an air chamber.