Design and evaluation of a test rig for measuring gear related losses within a Volvo Trucks gearbox

Abstract

With new EU regulations for CO2 emissions from trucks coming into effect 2025 and 2030 there is need at Volvo Trucks to reduce the emissions produced by their trucks. An important part in that is the transmission where losses due to friction and churning is preva lent. This ever-continuing work in finding and reducing losses requires better and more precise test rigs. The current gearbox test rig at Volvo Group Trucks Technology is not able to isolate and measure losses with the desired accuracy. This thesis therefore aimed at designing a new gear test rig through a collaboration between Chalmers University of Technology and Volvo Group Trucks Technology with better accuracy. Concepts were evaluated through the commonly used decision-matrix method with gradings based on available data and results from Finite Element Analyses and physical tests. Computational Fluid Dynamics simulations was then used to verify design choices. The newly designed gear test rig can measure smaller losses, run different test config urations faster and simultaneously reduce or eliminate many of the uncertainties present in Volvo GTT’s test rig. It also allows for axial visual inspection of the flow through its two transparent walls. One big difference between Volvo GTT’s test rig and the new rig is that the new one only tests a gear pairing and hence isolates the losses from that pair.