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 wheel driven utility vehicle comprising:
a frame;
a high speed motor having an output shaft with a gear thereon;
an offset planetary gear reducer driven by said output shaft of said gear of said high speed motor and affixed thereto;
said offset planetary gear reducer includes an output carrier interconnected with an output shaft;
said output shaft includes first and second chain drive sprockets;
forward and rearward wheel shafts each having a wheel sprocket;
a first and second chain;
said first chain interengaging said first chain drive sprocket and said forward wheel sprocket driving said forward wheel shaft; and,
said second chain interengaging said second chain drive sprocket and said rearward wheel sprocket driving said rearward wheel shaft.
2. A wheel driven utility vehicle as claimed in claim 1 wherein said motor is an alternating current motor controlled by a variable frequency alternating current drive.
3. A wheel driven utility vehicle as claimed in claim 1 wherein said planetary gear reducer is in the range of 20:1 to 30:1.
4. A wheel driven utility vehicle as claimed in claim 1 wherein said forward and rearward wheel sprockets are larger diameter than said first and second chain drive sprockets of said output shaft effecting a gear reduction in the range of approximately 2.5 to 5:1.
5. A wheel driven utility vehicle as claimed in claim 1 wherein said high-speed motor is a hydraulic motor.
6. A wheel driven utility vehicle as claimed in claim 1 wherein said high-speed motor is a pneumatic motor.
7. A wheel driven utility vehicle as claimed in claim 1 wherein said high-speed motor is a direct current motor.
8. A wheel driven utility vehicle as claimed in claim 1 wherein said output carrier includes an internal spline, said output shaft includes an external spline, said internal spline of said output carrier drives said external spline of said output shaft.
9. A wheel driven utility vehicle as claimed in claim 2 wherein said alternating current electric motor operates at full load between 7-8,000 rpm outputting approximately 14.75 ft-lbs. of torque.
10. A wheel driven utility vehicle as claimed in claim 9 wherein said first and second drive sprockets and said first and second wheel sprockets each have a reduction in the range of 2.5 to 5:1.