A New Process for Differential Gear Manufacturing
25 Apr,2025
Enhancing strength, efficiency and quiet performance for electric vehicles The manufacturing of differential gears went away from the Revacycle broaching process to forging more than 30 years ago. Today, where electric vehicles create a peak torque which are a multiple higher than in vehicles with internal combustion engines, the strength and the Noise Vibration Harshness (NVH) advantages of cut differential gears are revisited. The newly developed Coniflex Pro straight bevel gears combine several new features which make them stronger and quieter than past straight bevel gears and far superior to the forged version. The basic geometry of Coniflex Pro was developed especially for modern Phoenix free-form CNC machines and takes advantage of the “unlimited” geometric freedoms and the possibility of higher order, nonlinear kinematics. First field applications have proven that Coniflex Pro differentials have 30 percent lower root bending stress and 40 percent lower surface stress as forged differential gears. Many electric all-wheel drive vehicle applications with a front axle disconnect feature create high relative motions in the differential of the disconnected axle, which makes the transmission very noisy. Coniflex Pro gears have the lowest transmission error of any ever-produced straight bevel gear. While transmission errors of 50 microradians (μrad) or less are typical for Coniflex Pro, conventionally cut or forged straight bevel gears show between 300 and 2,000 μrad. Coniflex Pro differentials are therefore exceptionally quiet, even in case of high relative motions in disconnect axles.