Housing for a radical compressor

Abstract

A housing for a radial compressor is comprised of at least two housing parts manufactured of plastic material for receiving a compressor wheel and for forming a spiral-shaped compressor passage, wherein into the housing between compressor wheel receptacle and compressor passage an annular space is introduced that annularly surrounds the compressor wheel and into which a stabilization element is introduced.

Description

[0001]This is a cip application of pending international patent application PCT / EP2008 / 063146 filed Oct. 1, 2008 and claiming the priority of German patent application 10 2007 055 615.4 filed Nov. 20, 2007.TECHNICAL FIELD[0002]The invention concerns a housing for a radial compressor comprising two housing parts consisting of plastic and having a spiral-shaped compressor passage and a compressor wheel disposed in the housing.PRIOR ART[0003]In DE 103 14 209 B3 a radial compressor as a component of an exhaust gas turbocharger is described that is comprised of two shell-shaped housing parts that are injection-molded from thermoset material. This material has a high density so that, in comparison to other conventional charger housings of metal, no weight-related advantage results. DE 103 14 209 B3 attempts to counteract this in that into one of the housing parts chamber-like recesses are introduced that are separated from one another by partitions and that essentially extend concentrical...

AI Technical Summary

Benefits of technology

[0006]The invention has the object to produce a lightweight dimensionally precise housing for a radial compressor with satisfactory seal-tightness and high heat resistance from plastic material wherein, in case of damage of the compressor wheel, the risk of metal fragments flying about is to be reduced.

[0009]The housing parts manufactured of plastic material, comprised in particular of thermoplastic material and produced by the injection-molding process, for example, of polyphenylene sulfide (PPS), fulfill together with the annular space in which at least one stabilization element is introduced also high safety requirements, in particular in case of fracture of the compressor wheel. The annular space is located at the radial outer side of the compressor wheel so that broken-off wheel fragments that are thrown off tangentially outwardly as a result of the high rotary speed of the compressor wheel will impact on the annular space and the stabilizing element arranged therein. The walls of the annular space ensure already an effective reduction of the broken-off tangentially thrown wheel parts; in addition, there is the stabilizing element that is received in the annular space that, on the one hand, counteracts deformation of the walls of the annular space and improves as a whole the stability of the housing and, on the other hand, upon impact of a broken-off wheel fragment, provides effective damping. The stabilization element therefore has a double function: on the one hand, the annular space and thus the entire housing is supported or reinforced; on the other hand, in case of an accident, the protection from thrown-off wheel fragments is improved.

[0013]The manufacture of the compressor housing of thermoplastic material, in particular PPS, has the advantage of easy manufacture as well as good recyclability. In the manufacture by injection molding, a lost core technology is not required; manufacture is realized by injection molding by means of molds of a simple configuration that can be opened and closed. A further advantage resides in the manufacture of complex geometries of the housing, for example, a spiral passage with several undercuts. Finally, thermoplastic materials can be produced with high dimensional precision so that post-processing can be dispensed with or the need for it is limited. Moreover, the thermoplastic material is heat-resistant, pressure-tight and has excellent sound-insulating properties at minimal weight.

[0014]A further advantage resides in the possibility of configuring housing parts with constant wall thickness so that material accumulations are avoided and the risk of cavity formation is reduced.

[0015]The housing parts can be welded together in particular by way of ultrasonic welding. In order to be able to position the ultrasonic probe (sonotrode) in a simple way at the required welding seam, advantageously the contact area between the housing parts to be welded is adjacent to the axial end face of the housing, in particular adjacent to the intake side. Moreover, the contact areas between the housing parts are preferably located at a spacing to the spiral-shaped compressor passage; they are thus removed from the critical spiral area so that the air guiding action on the inner side of the spiral is not impaired by an undesirable burr caused by welding in the wall.

Problems solved by technology

The housing parts are glued together which however requires a relatively high manufacturing expenditure.

Thermoset resin as a material is furthermore characterized by a relatively high brittleness and high water absorption as well as a relatively minimal dimensional stability at high temperatures.

Moreover, there is great acoustic radiation and the manufacturing costs are also relatively expensive.

Because of the high wheel speeds of turbochargers there is the risk that upon damage of the compressor wheel metal fragments of the wheel will penetrate the housing of the compressor and will damage components in the engine compartment of the internal combustion engine.

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