JPS595809A - Turbine housing - Google Patents

Abstract

PURPOSE:To improve the thermal resistance of a scroll and to make available to highly heat up a working fluid, whereby improving a heat efficiency, by forming a scroll with a ceramic casing of reduced thickness around the inner side of metallic shell of radial inflow turbine. CONSTITUTION:A casing 11 of reduced thickness is formed with a ceramic of superior heat resistance around a rotor 2 of radial inflow turbine, and thereby constituting a scroll 3. While the casing 11 is engaged with a bearing housing 12, the casing 11 is retained by a plurality of retainers 14 projected inwardly from a metallic shell 13 provided externally thereof via a thermal insulating material 15. The casing 11 is resiliently supported by a coil spring 17 inserted into the supporting bore 13A of outer shell 13. In this manner, the scroll 3 has its surface in contact with a high temperature gas formed with a ceramic of superior heat resistance and therefore it is made possible to highly heat up the gas.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a turbine nozzle, and particularly to a radial turbine nozzle, in which the surface in contact with high-temperature gas is formed of ceramics (thereby, the tendency of the turbine inlet temperature to increase It was designed to do so.

Figures 1 and (i3) show an example of a conventional radial turbine and its nozzle.
11), / is a turbine housing provided with a scroll on the outer periphery of the turbine rotor tacho, and this housing forms a spiral flow path (scroll) 3 around the rotor tacho, and the high-temperature gas is directed to the person. Scroll from log 3
It is rotated by passing through and fed to the turbine rotor tacho. Here, the turbine housing is conventionally made of cast iron because it is always placed in contact with a high-temperature atmosphere due to the high-temperature gas passing through the scroll 3 and requires heat resistance.

However, in recent years, there has been a trend to raise the turbine inlet temperature in order to increase the thermal efficiency of gas turbines, and in such cast iron turbine housings, the turbine inlet temperature cannot be increased to 7000°C or higher due to the operating temperature limit of the material. There was a problem in that they were unable to respond to requests.

SUMMARY OF THE INVENTION In view of these problems, an object of the present invention is to provide a turbine housing whose surface that contacts high-temperature gas is made of heat-resistant ceramics.

The present invention will be described in detail below based on the drawings.

FIG. 2 (2) and [F]) show an embodiment of the present invention.

Here, // is a thin casing that forms the scroll 3, and the casing // is made of ceramic, which is a material with excellent heat resistance. As the ceramic, it is preferable to use, for example, silicon carbide, silicon nitride, or alumina ceramic. The casing formed in this way/
Fit the / into the bearing housing/yu of the turbine rotor tacho (see Figure 2 (G)), and also fit the casing //
The casing /l is held by a plurality of retainers lII that protrude inward from a metal shell /3 that surrounds the metal shell /3. In this example, beam retainers/l are provided at three locations.

/j- is a heat insulating material interposed between the retainer and the casing, and it is preferable to use a heat-resistant ceramic material such as glass wool or aluminum silicate for the heat insulator. be. /l is a support part of the retainer /g, and this support part /4 (, A is fitted into the support hole /, ?A on the outer shell /3 side, and its end and this support hole 73
A coil spring /7 is interposed between the pole) /A screwed onto k, and the spring force of this spring /7 biases the retainer /g against the casing //, thereby making the υ casing l/ Elastic support. The outer shell /3 is connected to the flange part /LA of duct 7g by bolts /9 to form a heat insulating space 20 between it and the casing l/.

In the turbine housing configured in this way,
Since the surface of the scroll 3 that comes into contact with the high-temperature gas is made of ceramic, it is heat resistant even in the case of high-temperature gas, such as 1000°C or more, which cast iron cannot withstand. Since it is supported by an elastic support structure from J, external vibrations are not directly transmitted to the casing//, and the heat insulating material 13 alleviates stress concentration on the held portion of the casing//, and heat is It is prevented from being transmitted to the retainer/g and the outer shell/3.

As explained above, according to the present invention, the portion of the scroll that comes into contact with high-temperature gas is formed into a thin casing made of heat-resistant ceramics, so it can be used even at turbine inlet temperatures of 1000°C or higher. Since this casing is elastically supported from the outer shell by a retainer via a heat insulating material using the spring force of a spring, the ceramic casing can be protected against external forces such as external vibrations. Yet again. Since the heat capacity of the turbine housing is smaller than that of conventional casting, the amount of heat released during heat soakback can be reduced. Furthermore, the ceramic casing of this example is thin and easy to manufacture.

[Brief explanation of drawings]

FIG. 1 (4) is a cross-sectional view showing an example of the configuration of a conventional radial turbine and its turbine housing, FIG. 1 (B) is a cross-sectional view of the housing taken along the line A-A, and FIG. A sectional view showing an example of the configuration of the turbine housing, FIG. 1 [F]) is a sectional view taken along the line B-B. /...Turbine housing, Co-turbine rotor, 3...Scroll, G...
・・Inlet //・Casing, /Yu・
・・Pairing Tsu・Using, 13・・Outer shell, /, 3A・・Support hole,
/l...retainer, /11. A Support part, /Left...Insulation material, /6...Bolt, /7...Spring, 7g・Duct, /ff
A...Flange part, /? ...Bolt, J...Insulated space. Patent applicant Nissan Motor Co., Ltd. Figure 1 (B)

Claims (1)

Claims: In a turbine housing for a radial turbine having a scroll, a thin ceramic casing forming the scroll and a metal outer shell forming a heat insulating space between the thin casing and the thin casing. A turbine housing comprising a plurality of retainers provided between the thin-walled casing and the metal outer shell to elastically support the thin-walled casing.