II. TYPES OF GEAR LOSSES A. Speed Dependant Losses Windage losses: As gears rotate, lubricant is flung off the gear teeth in small oil droplets due to the centrifugal force

42 Abstract:In this study, a test methodology for measuring load-dependent (mechanical) power losses of helical gear pairs is developed. A high-speed four-square type test machine is adapted for this purpose. Several sets of helical gears having 3 different pressure angles are manufactured, and their power losses under dip lubricated conditions are measured at various speed and torque levels. A general trend found in the experimental testing was that the higher the pressure angle, the lower the temperature-increase of the lubricant across the gearbox while being tested at identical conditions. This is an indication of the improved efficiency. Finally it was concluded that high-pressure angle helical gears (25°) pressure angle running at high speed provide improved performance over more traditional gear pressure angles (20°). Key Wordsload-dependent power losses, helical gear, pressure angle, efficiency.