Borg-Warner Automotive Gmbh

Borg-Warner Automotive Transmission & Engine Components Corporation

Thomas J Becker

David C White

Philip J Mott

Franklin R Smith

Roger P Butterfield

Timothy J Ledvina

Stanley K Dembosky

Roger G Young, Jr

A chain and sprocket system includes a plurality of chains and sprockets. The system includes a central shaft, two chains, and two identical sprockets. Although the two sprockets have identical size, shape, and features, they can be assembled onto the central shaft in different orientations. These orientations are achieved by rotating one sprocket with respect to the other. Assembling one sprocket onto the shaft in a different orientation from a second sprocket results in a system where the outer sprocket teeth of one sprocket are phased with respect to the outer sprocket teeth of the other sprocket. In this way, a phased chain and sprocket assembly is composed of identical sprockets, which eases manufacture and assembly.

Sprocket assembly for a phased chain system

A chain tensioner comprising an integrated tensioner body and tensioner arm. The tensioner body includes a fluid reservoir and a tensioner bore. The tensioner arm includes a pivot bore with a pivot pin disposed in the pivot bore to pivotally mount the tensioner arm. A check valve connecting the fluid reservoir to the tensioner bore permits fluid to flow into the tensioner bore, but not into the fluid reservoir. A plunger is slidably fitted into the tensioner bore and biased out from the tensioner bore by the fluid pressure in the tensioner bore. As a result, the plunger is forced against a fixed boss, causing rotational movement of the tensioner body and tensioner arm.

Tensioner with integral body and arm

A self-guiding chain assembly includes a silent chain with inner and outer links having depending toes. Traditional guide links are replaced by inverted tooth outer links with a crotch of lesser height than the crotch of the inner links. The outer links perform the self-guiding function and act to maintain the chain on the sprockets. The chain has particular application in engine timing systems that utilize phased chains and sprockets.

Self-guided chain assemblies

A camshaft (426) has a vane (460) secured to an end thereof for non-osciling rotation therewith. The camshaft also carries a sprocket (432) which can rotate with the camshaft but which is oscillatable with respect to the camshaft. The vane has opposed lobes (460a, 460b) which are received in opposed recesses (432a, 432b), respectively, of the sprocket. The recesses have greater circumferential extent than the lobes to permit the vane and sprocket to oscillate with respect to one another, and thereby permit the camshaft to change in phase relative to a crankshaft whose phase relative to the sprocket is fixed by virtue of a chain drive extending therebetween. The camshaft tends to change in reaction to pulses which it experiences during its normal operation, and it is permitted to change only in a given direction, either to advance or retard, by selectively blocking or permitting the flow of hydraulic fluid, preferably engine oil, through the return lines (494, 496) from the recesses by controlling the position of a spool (500) within a valve body (498) of a control valve in response to a signal indicative of an engine operating condition from an engine control unit (508).

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Auburn, NY, United States of America

Thomas J Becker