Gm Global Technolgoy Operations, Inc.

Electro-motive Diesel, Inc.

Daniel J Meyerkord

Gary Robert Svihla

James William Heilenbach

Anthony T Chobot

A method for fabrication of a locomotive diesel engine turbocharger turbine stage so as to avoid harmonic vibration in the turbine blades when the engine is operated at pre-selected throttle settings. Upon determining throttle settings for the engine and modeling of the turbocharger therefor, at least one natural vibration frequency of the turbine blades and a turbine nozzle vane excitation frequency as a function of turbocharger rotation speed are determined. Then the data obtained is analyzed to ascertain whether at least one data coincidence, that is whether a rotation speed correlative of a throttle setting has a coincidence over a predetermined range of both a natural frequency and said turbine vane nozzle excitation. If not, the model is suitable for fabrication of the turbocharger; if so, the model is modified by changing blade stiffness and/or vane numbering until no data coincidences are present.

Locomotive diesel engine turbocharger and turbine stage constructed with turbine blade vibration suppression methodology

A seal system for a four cycle engine turbocharger includes dual phase seals for limiting leakage from lubricated rotor support bearings to a turbine and/or compressor wheel of a rotor operational over an extended speed range. The dual phase seal combines features of a labyrinth seal, effective in a higher portion of the turbocharger rotor speed range, with features of an auger seal, found to be effective in a lower portion of the rotor speed range. The dual phase seals each include an outer cylinder on the rotor between a bearing and an associated wheel, an inner cylinder carried by a rotor support and surrounding the outer cylinder with close clearance, auger seal grooving formed in one of the cylinders on a portion thereof toward the bearing, labyrinth seal grooving formed in one of the cylinders on a portion thereof toward the wheel, and a pressure air supply to the labyrinth seal at a pressure which is reduced at rotor speeds in a lower portion of the speed range. Air pressure is supplied from an output of the compressor wheel to the labyrinth seal grooving for both the turbine and compressor ends of the rotor shaft. The dual phase seals operate without wear and provide cost effective and dependable rotor sealing at all rotor speeds without fragile or wearing parts, failure of which could cause damage to other components.

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Burr Ridge, IL, United States of America

Daniel J Meyerkord