초록 ▼

A hydraulically actuated, energy efficient wheelchair utilizes a pair of identical wheelchair drive units, with each unit having a constant speed battery powered electric motor driving a hydraulic pump and associated hydraulic motor. Hydraulic fluid flow between each pump and its hydraulic motor is

A hydraulically actuated, energy efficient wheelchair utilizes a pair of identical wheelchair drive units, with each unit having a constant speed battery powered electric motor driving a hydraulic pump and associated hydraulic motor. Hydraulic fluid flow between each pump and its hydraulic motor is controlled by the operator through the use of a solenoid actuated proportional control valve to determine the speed and direction of rotation of the hydraulic motor. One of these hydraulic motors is mechanically coupled to each wheelchair drive wheel. Means are provided to discharge excess pressurized fluid upstream of the hydraulic motor so as to minimize the backpressure on the pump and to thereby conserve driving energy and increase battery life. A method for hydraulically driving the wheelchair is also disclosed.

대표청구항 ▼

A hydraulically driven wheelchair capable of using hydraulic fluid and usable by an operator, comprising: a wheelchair framework including a chair capable of supporting the operator and further including at least one idler wheel; a housing system carried by said framework and including a hydraulic f

A hydraulically driven wheelchair capable of using hydraulic fluid and usable by an operator, comprising: a wheelchair framework including a chair capable of supporting the operator and further including at least one idler wheel; a housing system carried by said framework and including a hydraulic fluid rservoir for storing hydraulic fluid therein; power drive motor means carried by said housing system; hydraulic pump means mechanically coupled with said power drive motor means to acutate said pump means, said pump means including a hydraulic fluid inlet positioned within said reservoir and further including a hydraulic fluid outlet; a first reversible hydraulic motor having an output shaft, said motor fixed to said housing system and connected in fluid flow relationship with said pump means to rotate said output shaft of said first motor in response to fluid flow through said first motor; a second reversible hydraulic motor having an output shaft, said second motor fixed to said housing system and connected in fluid flow relationship with said pump means to rotate said output shaft of said second motor in response to fluid flow through said second motor; first and second wheelchair drive wheels mechanically coupled with said output shafts of said first and second hydraulic motors, respectively, to rotate said wheelchair drive wheels in response to rotation of said motor output shafts; a wheelchair steering control for generating control signals, said control system being carried by said framework and accessible to the operator; means for regulating the speed and direction of rotation of said first and second hydrualic motors, said regulating means being connected with said control system and responsive to said control signals from said steering control system so as to permit the operator to steer the wheelchair and control wheelchair direction and speed; and means for dumping pressurized fluid to said reservoir, said dumping means, in response to a predetermined level of pressure buildup across said regulating means, causing pressureized fluid from said pump means to flow directly to said reservoir, thereby diminishing back pressure against said pump means and reducing energy consumption by said power drive motor means when the wheelchair is moving at low speeds.