초록 ▼

An improved hydraulic drive system is provided for a vehicle having a plurality of ground engaging wheels which are each individually driven by a hydraulic motor to provide all wheel drive. The ground engaging wheels include a first pair of such wheels at or adjacent a first end of the vehicle and a

An improved hydraulic drive system is provided for a vehicle having a plurality of ground engaging wheels which are each individually driven by a hydraulic motor to provide all wheel drive. The ground engaging wheels include a first pair of such wheels at or adjacent a first end of the vehicle and at least one other such wheel at or adjacent a second end of the vehicle. The hydraulic drive system includes a hydraulic flow circuit that connects the hydraulic motors for the wheel(s) at the second end of the vehicle in series to each other, to the fluid source, and to the drive motors for the wheels at the first end of the frame, which latter drive motors are connected in parallel to each other. Such a vehicle will provide superior traction ability as at least one wheel on each end of the vehicle must slip to bring the vehicle to a halt.

대표청구항 ▼

A hydraulically driven riding mower having all wheel drive, which comprises: (a) a frame having an engine; (b) a plurality of ground engaging wheels attached to the frame for movably supporting the frame for movement over the ground, the wheels comprising a first pair of wheels carried adjacent a fr

A hydraulically driven riding mower having all wheel drive, which comprises: (a) a frame having an engine; (b) a plurality of ground engaging wheels attached to the frame for movably supporting the frame for movement over the ground, the wheels comprising a first pair of wheels carried adjacent a front end of the frame and a single rear wheel spaced on the frame from the front wheels and carried adjacent a rear end of the frame to provide a tricycle wheel configuration; (c) a plurality of cutting units carried on the frame for mowing grass, wherein the cutting units may be engaged with the ground during a mowing operation and when so engaged have at least some of their weight carried by the ground and not the frame; and (d) a hydraulic drive system for driving the ground engaging wheels of the frame, which drive system comprises: (i) a source of pressurized fluid which provides a pressurized fluid flow that is available for driving the ground engaging wheels; (ii) individual hydraulic drive motors operatively engaged to each of the ground engaging wheels of the frame; and (iii) means for connecting the hydraulic motors to the source of pressurized fluid in the following manner: the wheel drive motor for the rear wheel is connected in series to the fluid source and to the wheel drive motors for the front wheels in a manner that causes the pressurized fluid flow to pass substantially in its entirety through the wheel drive motor for the rear wheel to provide a maximum tractive effort on the rear wheel for a given pressurized fluid flow regardless of wheel slippage conditions on the front wheels; and the wheel drive motors for the front wheels being connected to each other in parallel in a manner that causes the pressurized fluid flow to be split when passing through the wheel drive motors for the front wheels.