Among numerous limited slip differentials, variable transmission ratio differentials have outstanding advantages such as the simplest structure, convenient maintenance, low wear, and long service life. They have great application value in off-road vehicles, but there are defects such as manufacturing difficulties and weak anti slip ability. To this end, a non circular gear differential is proposed, which utilizes the characteristics of simple machining and assembly of non circular gears and good interchangeability to solve the manufacturing and installation problems of variable transmission ratio differentials. At the same time, through theoretical and experimental research, the dynamic anti slip mechanism of variable transmission ratio differentials is revealed, and effective methods to increase the anti slip ability of variable transmission ratio differentials are proposed. The research results provide a theoretical basis for designing high-performance variable transmission ratio differentials.
(1) A variable transmission ratio differential composed of non circular gears is proposed. Due to the point meshing transmission between non circular gears and ordinary cylindrical gears, this differential has outstanding advantages over non conical gear differentials in terms of good interchangeability and strong axial fault tolerance.
(2) The dynamic anti slip mechanism of the variable transmission ratio differential indicates that the inertia torque of the pulley has a positive effect on improving the overall traction of the vehicle, which is an important reason for the high anti slip ability of the variable transmission ratio differential.
(3) Increasing the eccentricity of non-circular gear under the static anti-skid mechanism is the only way to improve the anti-skid capability of the variable transmission ratio differential, but the dynamic anti-skid mechanism shows that increasing the input speed of the differential can also effectively improve the anti-skid capability of the differential, so the non-circular gear with small eccentricity can also produce large anti-skid capability, which is extremely beneficial to avoid the tooth defects of non-circular gear.
(4) Under the condition of unilateral wheel slip, as the input speed of the non circular gear differential increases, the average forward speed of the vehicle will significantly increase, but at the same time, the frequency and amplitude of the impact on the vehicle and passengers will also increase. Therefore, the input speed of the differential needs to be limited to a certain extent.