Sound Control On J I Case 90 Series Non-Cab Ag Tractors

Abstract

Operator's station sound control technology was applied to two-wheel-drive non-cab agricultural tractors. A sound level design goal of 88 dB(A) was established, with consideration given to government regulations, expected industry trends in cab and non-cab tractor sound levels, and anticipated demand for quiet non-cab tractors. To establish the technical feasibility of this goal on non-cab tractors, a 1974 research and demonstration program was undertaken using a J I Case Model 1370 non-cab 4 Post ROPS Ag tractor. The initial operator's station sound level was 95 dB(A) at rated engine speed and 100% drawbar load, requiring a 7 dB(A) sound level reduction. Major sound sources and sound transmission paths were identified and modified until the goal was achieved, and results incorporated into the 90 Series non-cab 4 Post ROPS tractors in the early design stages. It was concluded that two-wheel-drive tractors of up to 180 PTO horsepower can be designed and commercially produced to achieve operator's station sound levels of less than 90 dB(A); that this is cost effective if done during the early design stage; and that sound source analysis is beneficial in achieving overall sound level reductions.