Abstract: A riding lawnmower vehicle includes two main drive wheels, at least one caster wheel, an electric traction motor, an internal combustion engine, a generator driven by the internal combustion engine, and a lawnmower. The electric energy generated by the generator can be supplied directly or via an electric accumulator to the electric traction motor. The main drive wheels are independently driven by the electric traction motor, which can operate as a traction power source. When viewed from one end to the other end in the width direction of the vehicle, the internal combustion engine and a secondary battery operable as the electric accumulator overlap each other, and the main drive wheels overlap at least a part of at least one of the internal combustion engine, the generator, the secondary battery, a fuel cell, a capacitor, an inverter, a cooling device, a mower driving motor, and a grass-collecting duct.

Abstract: An improved differential unit for an integrated hydrostatic transmission (IHT) is provided. The differential unit comprises an input gear, a cross-shaft disposed within a central opening of the input gear, and a pair of clutch members disposed coaxial with the input gear. One of each clutch member is disposed on opposite sides of the cross-shaft. A first plurality of friction members extend from each clutch member. The differential unit also comprises a pair of side couplings, each coaxially disposed within one of the clutch members, and a second plurality of friction members extending from each side coupling. Each clutch member includes a cam surface that comes in contact with the cross-shaft when the differential unit is under normal operating conditions. Alternative embodiments are also described herein.

Abstract: An improved differential unit for an integrated hydrostatic transmission (IHT) is provided. The differential unit comprises an input gear, a cross-shaft disposed within a central opening of the input gear, and a pair of clutch members disposed coaxial with the input gear. One of each clutch member is disposed on opposite sides of the cross-shaft. A first plurality of friction members extend from each clutch member. The differential unit also comprises a pair of side couplings, each coaxially disposed within one of the clutch members, and a second plurality of friction members extending from each side coupling. Each clutch member includes a cam surface that comes in contact with the cross-shaft when the differential unit is under normal operating conditions. Alternative embodiments are also described herein.