Abstract: A heavy duty wheeled vehicle for an industrial environment is electrically driven by one or more switched reluctance motor traction drive system connected to the wheels. The switched reluctance motors are powered by an electrical generator that is driven by an engine, such as a diesel engine, which may run at a substantially constant RPM. A digital control system provides operator displays and controls power conversion from the generator, as well as providing maintenance and control functions for the switched reluctance motors. A heavy-duty hoisting apparatus electrically drives a hoisting mechanism using an SR motor, providing power for lifting a load. The heavy-duty hoisting apparatus may include an engine and generator or provide power to the SR motor from an external source.
Type:
Grant
Filed:
October 3, 2003
Date of Patent:
April 10, 2007
Assignee:
LeTourneau, Inc.
Inventors:
Ronald A. Johnston, Dwight Baker, Nelson L. Stoldt, Paul K. Schufeldt, Peter J. Bradley
Abstract: A locking mechanism is disclosed for use on the legs of a jack-up offshore platform. Each chord of the legs includes a rack for cooperation with pinions used in raising and lowering the legs. The locking mechanism of the invention includes a rigid frame attached to the hull of the platform and housing a plurality of vertically aligned toothed chock segments adapted to engage the teeth of the rack on a leg. The chock segments have upper and lower inclined surfaces which cooperate with upper and lower movable wedges for supporting the chock segments. The design makes the chock segments sufficiently adjustable for independent alignment and engagement of the teeth of each chock segment with the corresponding teeth of the rack. Dimensional variances in the rack teeth spacing, resulting from manufacturing tolerances, thereby are accommodated and force concentrations between the rack teeth and chock teeth are minimized.
Type:
Grant
Filed:
June 26, 1997
Date of Patent:
June 29, 1999
Assignee:
LeTourneau, Inc.
Inventors:
Mahmoud K. M. Darwiche, Michael J. Dowdy, Julian F. Bowes
Abstract: Propulsion control system for electrically powered vehicles, typically heavy duty off-road type work vehicles having electric motor driven wheels. In embodiment shown, power is supplied from direct current generator driven by internal combustion engine. Motor and generator field excitation is automatically varied responsive to selected machine operating conditions and improved means are provided to accomplish such variation. The provision and application of certain propulsion system parameters effects improved machine performance with minimum demand for operator skill and attention.
Abstract: Propulsion control system for electrically powered vehicles, typically heavy duty off-road type work vehicles having electric motor driven wheels. In embodiment shown, power is supplied from direct current generator driven by internal combustion engine. Motor and generator field excitation is automatically varied responsive to selected machine operating conditions and improved means are provided to accomplish such variation. The provision and application of certain propulsion system parameters effects improved machine performance with minimum demand for operator skill and attention.
Abstract: Propulsion control system for electrically powered vehicles, typically heavy duty off-road type work vehicles having electric motor driven wheels. In embodiment shown, power is supplied from direct current generator driven by internal combustion engine. Motor and generator field excitation is automatically varied responsive to selected machine operating conditions and improved means are provided to accomplish such variation. The provision and application of certain propulsion system parameters effects improved machine performance with minimum demand for operator skill and attention.