Image Number 3 for United States Patent #4821591.
The invention relates to a planetary gear type auxiliary gearbox intended to be inserted between a main gearbox and a transmission to the driving wheels in a motor vehicle. The input shaft of the planetary gear is rigidly connected to a sun wheel, while the output shaft of the planetary gear is rigidly connected to a planet wheel carrier carrying a plurality of planet wheels meshing with the sun wheel.The planetary gear further includes a clutch ring non-rotatably connected to the gearbox housing and a clutch ring non-rotatably connected to the input shaft. The invention is distinguished in that the ring gear of the planetary gear is formed with engagement teeth at its axial ends, in that the clutch rings are arranged on either side of the planet wheels and in that the ring gear is axially movable to enable alternative engagement with the clutch rings by its engagement teeth. The invention results in favorable load distribution with regard to both torque and bending stresses. In addition, there is obtained a simple structure which allows the gearbox to be formed such that its length is comparatively short.