Drive system for electric vehicles

Claim 1

A drive system for an electric vehicle having a frame and ground-engaging drive wheels, said drive system comprising: a. an electric motor the main elements of which consist of a case carrying the field windings of the motor and being rotatably mounted on the frame of said vehicle, and an armature carrying the armature windings of the motor and being rotatable in said case coaxially therewith, whereby when electric power is supplied to said motor said case and armature will rotate in opposite directions, each being driven by the reactive force of the other, b. rechargeable electric storage batteries operable to supply electric power to said motor, c. a first drive train operably connecting one of said main motor elements to said vehicle drive wheels, whereby the latter are driven by the former to propel said vehicle, the torque delivered to said power train by said motor being variable directly with the differential between the rotational speeds of said motor elements, d. an electric generator, e. a drive connection between the other of said main motor elements and said electric generator, whereby the latter is driven by the former, the electric output of said generator being connected in recharging relation to said storage batteries, f. a second drive train interconnecting the main motor element which is connected to said vehicle drive wheels by said first-named drive train to the input of said generator, whereby the latter may be driven by the former, in the same direction it is driven by the other of said motor elements, and g. a uni-directional clutch interposed in said second drive train and operable to prevent said generator from driving the motor element to which it is connected by said second drive train by reverse operation of said drive train, whereby as the vehicle speed reaches or exceeds a predetermined equilibrium level at which the speed of said wheel-drive motor element equals or exceeds the speed at which the generator is driven by the other motor element, said clutch will engage to drive said generator, thereby locking said motor elements at a fixed differential speed of rotation, which deprives the motor of the ability to generate the additional motive power which would be required to drive the vehicle at any speed higher than said equilibrium level.