Extremely low noise levels at high power densities are achieved with a new inverted tooth silent chain system Two chains of random link design are phased such that the first order and subsequent odd orders of sprocket mesh frequency noise are canceled while remaining even orders are minimized by link randomization
Current chain noise reduction practice has applied randomization with a primary emphasis on finer link pitch to control mesh frequency noise As the link pitch becomes finer, however, the chain loses strength and package size must increase to compensate The principle of operation of the new phased chain system is not primarily a function of the chain pitch Therefore, significantly higher power transmission densities can be achieved in the same package without sacrificing noise benefits
To achieve the noise cancellation, motive power is transmitted by two chains mounted in such a manner that a specified phased lag exists between them at all times The noise reduction efforts described in this paper were achieved with a phase lag of 180°
The new system is readily manufacturable It is made with current processing technology Its first production volume application is in the 1995 Chrysler Corporation LH vehicles