Experimental study of the influence of speed and load on thermal behavior of high-speed helical gear trains

You are here: Homepage > Search

Experimental study of the influence of speed and load on thermal behavior of high-speed helical gear trains

Handschuh, R. / Kilmain, C.

High speed, heavily loaded and lightweight gearing components are common-place in rotorcraft systems. These systems are expected to deliver high power from the gas turbine engines to the high-torque/low-speed rotor with reduction ratios in the range of 25:1 to 100:1. The thermal behaviour characteristics of mechanical components is the least understood and has received the least amount of attention in the open literature. An experiment has been conducted on an aerospace-quality helical gear train to investigate the thermal behaviour of the gear system as speed load, and lubricant flow rate were varied. The objective of this paper is to present the effects of speed, load and lubricant jet resources on the operating performance and resultant fling-off temperatures. Test facility, test instrumentation, test hardware, data acquisition and test operation are described. The results are presented: fling-off data, shroud-lubricant jet pressure effects on operational performance, rake data, array data. It could be shown that speed and load affected lubricant fling off temperatures measured across the gear mesh face width and at the axial location due to the helical gear mesh axial pumping. Changing speed from 12500 to 15000 rpm had a more dramatic effect than increasing load from 30 % to 100 %. Reducing the lubricant jet pressure from 80 to 60 psi reduced the power necessary to drive the facility, but the effect was rather small and caused the lubricant temperature difference between inlet and exit to increase up to 10 deg F. Shrouding for this particular facility produces the best results for the experiments conducted. Anything less than full shrouding of this gear train caused higher power loss and increase temperature difference between the inlet and exit lubricant temperature.