Borgwarner Inc.

Kai Tanaka

Matthew Brian Cooley

Alexander George Milburn

Tim Weiland

High cycle fatigue (HCF) in a turbine wheel of a sector-divided dual volute turbocharger, particularly a turbocharger where the tongue-to-blade gap is as small as from 1-3% of the wheel diameter, is reduced, by locally increasing the volute cross-sectional area just upstream of the tongues. Thereby, it becomes possible to reduce the force function of the exhaust gas pressure onto the turbine wheel blades. Modifying how the pressure presents itself to the wheel reduces blade excitation and, ultimately, HCF of turbine wheels. In another aspect of the invention, the angle of the tongues are modified to direct the exhaust more directly onto the turbine wheel than conventional tongues. It is surprising that this approach not only accomplishes the desired result, but does this without significant loss of turbine stage efficiency.

Method of reducing turbine wheel high cycle fatigue in sector-divided dual volute turbochargers

A turbocharger includes a turbine housing including an interior surface defining a turbine housing interior. The interior surface extends between a turbine housing inlet and a turbine housing outlet. The turbine housing also includes a wastegate duct disposed downstream of the turbine housing inlet and defining a wastegate channel. The turbocharger also includes a valve seat disposed about the wastegate channel, with the valve seat having a valve seat plane extending along the valve seat. The turbocharger further includes a wastegate assembly including a valve element engageable with the valve seat. The wastegate channel extends along a channel axis, and the channel axis is obliquely oriented with respect to the valve seat plane such that the wastegate channel and the valve element are configured to direct exhaust gas to a catalytic converter.

Wastegate assembly for use in a turbocharger and system including the same

A turbocharger includes a turbine housing. The turbine housing includes a turbine inlet wall defining an inlet passage, an exducer shroud wall defining an exducer interior, a turbine outlet wall defining an outlet passage, a wastegate port wall defining a wastegate channel, and a bushing wall coupled to the wastegate port wall and defining a bushing boss extending along a bushing axis, and a valve seat disposed about the wastegate channel. The turbocharger also includes a wastegate assembly. The wastegate assembly includes a valve element engageable with the valve seat. The wastegate port wall is disposed outside of the exducer interior such that the wastegate port wall and the bushing wall are configured to be thermally decoupled from the turbine inlet wall and such that relative displacement between the valve seat and the bushing axis is reduced during operation of the turbocharger.

Turbine housing of a turbocharger

A wastegate assembly includes a valve arm moveable between a first position and a second position to control flow of exhaust gas to a turbine housing interior of a turbocharger. The valve arm includes a proximal end, a distal end spaced from the proximal end, and a valve arm orientation projection spaced from the distal end and extending away from the proximal end. The wastegate assembly also includes a valve body coupled to the distal end of the valve arm that is moveable with the valve arm. The valve body includes a valve body orientation component, and the orientation projection of the valve arm extends toward and is orientable with the orientation component of the valve body to orient the valve arm relative to the valve body. The valve body is disposed between the orientation projection of the valve arm and the distal end of the valve arm.

Growing community of inventors

Mills River, NC, United States of America

Kai Tanaka