Evaluation of acoustical power of a gear mechanism

A technique which combines a dynamic calculation of a multistage gear mechanism and the statistical energy analysis (SEA) is used to determine the acoustical power emitted by the mechanism. The gear mechanism is represented as a ultimass and multicoupling dynamical system. The dynamical calculation of the mechanism is used to determine the energy introduced in the mechanism and the energy transmitted to its housing. An acoustical model is used to perform the acoustical calculation. This model includes the gear mechanism, housing, and the frame, internal and external acoustical spaces. The combination of dynamic and acoustic models allows to utilize the advantage of dynamic calculation accurately describing the mechanism's performance and the SEA method for describing an acoustical model having the elements of high mode density in a wide frequency range. This technique is used to investigate the causes of a high noise level of a shuttle loading mechanism of a multiopening weaving machine and to find the means to reduce its noise level. It is found that the mechanism is the dominant source of noise of this machine because it has two heads of high velocity gear trains. The structural noise is greater than air noise and the housing noise is predominant in the noise level of the mechanism. A change in the housing design was proposed to reduce noise level