Cummins Engine Company, Inc.

Simpson International (uk) Ltd.

Thomas E Reinhart

Paul A Hayes

Alan H Zhao

Terrence M Shaw

Dennis R Tibbetts

Charles E Long

Kwin R Abram

Jeffrey D Saueressig

Mark A Zen Ruffinen

An improved torsional vibration isolator assembly for an engine is provided which includes a non-linear spring device which effectively minimizes the transmission of torsional vibrations to the engine's gear train throughout all engine operating frequencies and conditions while limiting relative movement between the engine's crankshaft and crank gear so as to maintain timing error within acceptable limits. The improved torsional vibration isolator is designed to absorb torsional vibrations transmitted from the crankshaft so as to substantially isolate the entire engine gear train, including the crank gear, from the torsional vibrations throughout all engine operating conditions and frequencies, including at and below the natural frequency, i.e. crank resonance, of the crankshaft. The crank gear isolator includes resilient elements positioned in cavities formed between engaging projections formed on inner and outer rings of the assembly. The resilient elements and cavities are sized to create an expansion volume which is filled by the deforming resilient element during operation to limit further relative movement. The assembly may include a torsional vibration damper for dampening torsional vibrations transmitted from the crankshaft, especially during crankshaft resonance.

Crankshaft gear torsional vibration isolator assembly for an engine

An improved engine gear drive train arrangement is provided which effectively minimizes the crankshaft torsional vibrations at the location of the gear train, for engines with a front gear train. A flywheel is resiliently connected to the rear end portion of the crankshaft so as to resiliently connect a driven unit to the crankshaft. An extra inertial device is connected to the front end portion of the crankshaft and includes an inertia so selected as to cause a nodal point of the first torsional vibration mode of the crankshaft to be located in the vicinity of the crank gear to minimize the amplitude of torsional deflection of the crankshaft at the crank gear. Also, the device for resiliently connecting the flywheel to the rear end portion of the crankshaft may include resilient members positioned in cavities formed by engaging rings. The nodal point of the first torsional mode of the crankshaft is optimally positioned close to the crank gear by selecting an inertia for the rear mounted flywheel, an optimum inertia for the front mounted inertial device and a resilient material for the flywheel connecting device having the appropriate stiffness, so that the combination of these features achieves the desired nodal point positioning for a given engine or application.

Engine drive train having a front gear train with improved torsional

An apparatus and method for altering the acoustic signature of an internal combustion engine is disclosed. Several techniques for altering the acoustic signature of an engine are shown, including time-varying, disabling or cutout of individual cylinders of an engine in a random fashion in order to reduce the periodic characteristics of the exhaust noise of the engine. Alternate embodiments include offsetting crank pins to transform an even firing engine into an uneven firing engine, inhibiting the fueling of individual cylinders, and inhibiting the ignition signals provided to individual cylinders. A combination of the above techniques may also be implemented in order to disperse the exhaust noise energy present over a wide frequency range, making acoustic detection of the exhaust signature difficult. Cylinder cutout schemes are implemented over a single or multiple engine cycle to disperse exhaust noise pulses over time and randomize measurable spectral noise composition.

Device and method for altering the acoustic signature of an internal

A method and device for providing a time-varying minimum engine speed setting are disclosed. A first embodiment of the device includes programming within an electronic engine control module for variably supplying fuel to an engine via variable activation periods for the fuel injectors of a fuel injected engine. In another embodiment a rotating cam provides a positionally time-varying mechanism stop against which the throttle linkage is positioned when released by the operator. In another embodiment of the invention, a solenoid provides a minimum engine speed setting which varies between two different positions. The two different positions are produced by a solenoid, which is activated and deactivated at random to produce a pseudo-random variation in minimum engine speed. Pulse-width activation of the solenoid provides variable positioning of the solenoid actuator between the two end stop positions of the solenoid actuator.

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Columbus, IN, United States of America

Thomas E Reinhart