Offset drive system for utility vehicles
View Patent ↗A wheel driven utility vehicle includes a frame and two small volume high speed alternating current electric motors arranged side by side for driving the vehicle. Alternatively high speed direct current, hydraulic or pneumatic direct current motors may be used with suitable controls. Each motor has an output shaft which drives an offset planetary gear reducer. Each offset planetary gear reducer is affixed to the electric motor and includes an output carrier interconnected with an output shaft. Each output shaft includes first and second chain drive sprockets which drive chains interconnected with shafts driving the front and rear wheels respectively. Each offset planetary gear reducer enables use of space saving high speed relatively low-torque alternating current electric motors with attendant large speed reductions. Gear reduction enables the production of sufficient torque at the wheels of the vehicle. Applications in addition to utility vehicles are also specifically contemplated.
1. A utility vehicle comprising a frame; said frame includes two sides thereof each supporting a first chain driven wheel shaft having a sprocket for driving a forward wheel and a second chain driven wheel shaft having a sprocket for driving a rearward wheel; each side of said frames includes a chain drive shaft having two sprockets thereon for driving first and second chains, said chain drive shafts being in alignment with each other, said first chain intermeshing with one of said sprockets of said chain drive shaft and said sprocket for driving said forward wheel and said second chain intermeshing with said other sprocket of said chain drive shaft and said sprocket for driving said rearward wheel; two alternating current motors residing adjacent each other, each of said alternating current motors having an output shaft, said output shafts of said alternating current motors each include a pinion gear for driving a respective offset planetary gear reducer to effect speed reduction and increase torque; said alternating current motors controlled by a variable frequency drive to control the speed of said alternating current motors; each of said offset planetary gear reducers includes a stationary housing having a ring gear affixed thereto; each of said planetary gear reducers includes a carrier having at least one planetary gear intermeshing with said ring gear, and, said carrier includes an output spline; each of said planetary gear reducers includes a gear driven by said pinion gear of said output shaft of said alternating current motor, said gear driven by said pinion gear of said output shaft of said alternating current motor includes a portion having a sun gear thereon which intermeshes and drives said at least one planet gear of said carrier; each of said chain drive shafts includes a spline thereon which intermeshes with said output spline of said carrier and is driven thereby; said planetary gear reducers effecting a speed reduction in the approximate range of between 20-30:1; and, said chain drive sprockets in combination with said wheel shaft sprockets effecting a speed reduction in the approximate range of 2.5-5:1.
2. A method for using high-speed motors in a utility vehicle, comprising the steps of:
orienting two high speed motors each having shaft driven pinion gears adjacent each other such that their shaft driven pinion gears are arranged on opposite sides of the utility vehicle;
mounting offset planetary gear reducers in engagement with said shaft driven pinion gears, each of said planetary gear reducers includes a gear driven by said shaft driven pinion gears, said gear driven by said shaft driven pinion gear includes a shaft portion formed as a second pinion gear which drives a planetary gear set and carrier reacting against a ring gear in a stationary casing of said planetary gear reducer, said carrier of said planetary gear reducer includes a splined output, and each of said splined outputs being on the same axis of each other;
coupling an output shaft to said splined output of said planetary gear reducer and driving said output shaft at a desired rate; and,
driving, with chains, said wheel shafts of said vehicle.
3. A method for using high-speed motors in a utility vehicle as claimed in claim 2 wherein said high speed motors are electric motors and further comprising the steps of controlling the speed of said electric motors with variable frequency drives.
4. A method for using high-speed motors in a utility vehicle as claimed in claim 2 wherein said high-speed a motors are hydraulic motors.
5. A method for using high-speed motors in a utility vehicle as claimed in claim 2 wherein said high-speed motors are a pneumatic motors.
6. A method for using high-speed motors in a utility vehicle as claimed in claim 2 wherein said high-speed a motors are direct current motors.