Turbine housing for gas turbochargers

Abstract

A turbine housing for exhaust gas turbochargers includes an outlet pipe and an external housing connected therewith. A rotor housing is disposed in the external housing and has a pipe-shaped neck operably coupled with the outlet pipe and axially displaceable relative to the same. A separate sealing ring is positioned operably between the neck and the outlet pipe, supported by the outlet pipe, and has an inwardly turned sealing portion sealingly and slidingly engaging the neck to form a secure gas seal therebetween.

Description

CLAIM OF PRIORITY[0001]Applicants hereby claim the priority benefits under the provisions of 35 U.S.C. §119, basing said claim of priority on German Patent Application Serial No. 10 2009025054.9, filed Jun. 10, 2009. In accordance with the provisions of 35 U.S.C. §119 and Rule 55(b), a certified copy of the above-listed German patent application will be filed before grant of a patent.BACKGROUND OF THE INVENTION[0002]The present invention relates to a turbine housing for exhaust gas turbochargers and the like.[0003]Internal combustion engines for motor vehicles are increasingly charged by turbochargers in order to reduce fuel consumption. However, the weight of the exhaust system itself also affects fuel consumption. Turbochargers should therefore be as lightweight as possible. This need for a lightweight construction conflicts with the fact that when in use, turbochargers are subjected to significant mechanical stresses and especially extremely high thermal loads that demand a robus...

AI Technical Summary

Benefits of technology

[0005]Hence, an object of the present invention is to provide a turbine housing for an exhaust turbocharger which compensates for temperature expansion between the rotor housing and the exhaust gas outlet, has maximum sealing effect for the internal system, while at the same time uses very thin materials, and avoids welding in the sensitive outlet area of the rotor housing.

[0009]A distinctive aspect of the inventive turbine housing is that the sealing ring is turned inwardly. The sealing ring is pushed elastically over the outlet area of the neck, i.e., the internal system that conducts the exhaust gas. The sealing ring provides sealing, and renders the neck axially moveable or displaceable relative to the outlet pipe. The very good sealing effect achieved by the sealing ring configured in this manner is a result of the radially oriented elastic tension applied by the sealing ring to the outside surface of the neck. The high elasticity of the sealing ring results from the end thereof being turned inwardly.

[0010]The inward turning of the sealing ring end shall be construed to mean inverted across an angular area of at least 180°. The turned sealing ring end functions like a spring that resiliently urges the same axially under tension against the outside of the neck. It can be assured that the neck is positioned securely against the sealing ring, or the sealing ring against the neck, by using an expanding mandrel that is inserted into the neck after assembly to expand the neck. With this construction, it is also possible to use greater production tolerances with respect to the neck, because the sealing effect that is generated between the neck and the outlet pipe is attained by adjusting the sealing gap through use of the expanding mandrel.

[0015]In addition, the sealing ring can be made of a very thin-walled material. The thickness may be less than 1.0 mm. This has a positive effect on starting the catalytic converter.

[0016]The outlet pipe may be a integral component of a flange for connecting to the exhaust system, and therefore is generally thicker than the sealing ring. Because of this, fusion welding of the sealing ring and the outlet pipe may be improved by using a support ring that surrounds the sealing ring, in addition to the sealing ring. In this manner, components that essentially have the same thickness are welded to one another. This facilitates the welding due to more uniform heat input.

[0017]The support ring may also be embodied in a double layer to increase the thickness. This also further enhances the elastic properties of the sealing ring.

Problems solved by technology

However, the weight of the exhaust system itself also affects fuel consumption.

This need for a lightweight construction conflicts with the fact that when in use, turbochargers are subjected to significant mechanical stresses and especially extremely high thermal loads that demand a robust construction.

Thus, appropriate thermal compensating elements must be provided, although the same often have leaks.

The arrangement depicted in DE 100 22 052 A1 makes it possible to connect the internal system to the external system in a sealed manner, but it does not address the thermal stress problems that occur, except by deforming the components.

This results in the risk that the internal system or the rotor housing will collide with the turbine rotor.

DE 10352960 A1 indicates how the expansion can be compensated, but economic fabrication of the subject housing may be jeopardized by the thermomechanical loads that occur as result of this construction, by the required material properties, and by the production tolerances required for smooth operation.

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