In this paper, the models for different power loss sources in transmissions from literature are applied and compared, which form the two methods - ISO 14179-2 and the joint model to estimate the power losses in a transmission. A 2-speed transmission in an electric vehicle is used as a case study to compare the two methods and validate them with experimental data.
In this study, a finite volume CFD simulation model of a single-stage injection-lubricated test gearbox was applied to investigate its oil flow and no-load power loss. The results provide physically plausible information on the oil supply and its distribution.
The proof of the reliability of a gear drive is now an additional requirement. In Europe, the acceptance authorities for wind turbines are requesting a system reliability proof from gearbox manufacturers. The AGMA committee reviewing the AGMA 6006 standard for wind turbines is considering adding a chapter about design for reliability. However, reliability considerations are not new; NASA, for example, was in the 1980s using reliability concepts for gear drives.
With the increasing mechanical power capacity of gearboxes, the thermal power limit tends to become the limiting factor. To achieve a balanced system, the gear unit needs extra cooling. Using a fan that is mounted to a fast rotating shaft is a common solution. For this solution an optimal design is investigated.