Design and Validation Test of a Differential with Pm Bevel Gears

Currently according to the restructuring and development policies for green and low carbon sustainableindustries, the development of electric vehicle industry is regarded as the important goal to achieve thelow-carbon city strategy. The mobile scooters, electric wheelchairs, beach cars, and even four-wheeledmotorcycles are all the new attractive subject of electric vehicles. Because the requirements on lightweight,high efficiency, low cost are particularly high, differentials with powder metallurgy bevel gears are oftenused in these vehicles. However, in order to achieve the lightweight design of the differential, the contactproblems of multiple gear pairs must be solved. But the tooth contact problem is affected by the deformationof the shafts and the teeth, as well as the manufacturing/assembly errors, consequently vibration and noise arenot only easily induced in the differential, but also the uneven load sharing among the power-split gear pairsand the concentrated contact loads on engaged flanks. The load capacity will be thus reduced.Based on the results of the project “Flank Modification for PM Spur Bevel Gear Drives with SphericalInvolute Flanks” of the year 2014, the loaded tooth contact analysis model for straightly toothed bevel gearswill be expanded to the model for differential in this project. The analysis of load, error and also design of themodified flanks of the differential gears will be carried out. In the project, a differential will be developed.The modified flanks of bevel gears will be designed based on the LTCA model. Afterwards the PM bevelgears and the housings will be manufactured and inspected. Finally the contact pattern test, the fatiguerunning test, and vibration measurement are also conducted to verify the feasibility of the design approach.