Vehicular propulsion system

• US 4,081,693 A
• Filed: 07/18/1975
• Issued: 03/28/1978
• Est. Priority Date: 07/18/1975
• Status: Expired due to Term

• Current Assignee: Voltek Incorporated
• Original Assignee: Gordon R. Stone
• Inventors: Stone, Gordon R.
• Primary Examiner(s): Smith, Jr., David
• Application Number:
  US05/597,031
• Time in Patent Office: 984 Days
• Field of Search: 307/48, 307/56, 307/66, 307/80, 307/85-87, 136/100 R, 136/100 M, 136/86 B, 136/86 R, 123/119 E, 320/3, 320/43, 320/61, 320/8, 320/14, 336/140, 180/65 R, 180/65 A, 324/94, 429/22, 429/17, 429/29, 429/27, 73/445, 73/452, 204/1 H, 204/195 G, 204/248, 204/274
• US Class Current: 307/66
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 2260/28 Four wheel or all wheel drive
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 12/065 with plate-like electrodes or stacks of plate-like electrodes
• CPC Class Codes: H01M 16/003 of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers
• CPC Class Codes: H01M 2004/024 Insertable electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A vehicular propulsion system comprising an electric drive motor and a source of electric power for energizing the motor drive. The power source comprises at least one fuel cell and at least one primary air cell. The air cell has a consumable replaceable anode and produces hydrogen as a product of the discharge reaction thereof. The fuel cell produces electrical energy when supplied with hydrogen. The hydrogen so produced by the primary cell is transmitted to the fuel cell. A switching arrangement is provided to alternately and selectively interconnect the fuel cell and primary air cell to the motor drive. The switching arrangement is responsive to the power output of the fuel cell whereby upon the power drain of the motor drive exceeding that available from the fuel cell, power will be supplied from the primary air cell.

Claims

1. A propulsion system for a wheeled vehicle comprising electric motor drive means for driving wheels of the vehicle and a source of electric power for energizing said drive means, said power source comprising at least one fuel cell and at least one primary air cell utilizing a liquid electrolyte which is heated during the discharge reaction of the primary cell, said air cell having a consumable replaceable anode and producing hydrogen as a product of the discharge reaction thereof, said fuel cell adapted to produce electrical energy when supplied with hydrogen, means for transmitting the hydrogen so produced by the primary cell to the fuel cell, means in heat-exchange relationship with said fuel cell, means for recirculating the heated electrolyte through the heat-exchange means thereby to cool said primary cell and heat said fuel cell, a radiator through which the heated electrolyte may be recirculated when its temperature exceeds a predetermined level, switching means adapted alternately and selectively to electrically interconnect the fuel cell and primary air cell to the drive means, said switching means being responsive to the power output of the fuel cell whereby upon the power drain of the drive means exceeding that available from the fuel cell power will be supplied from the primary air cell, said switching means including means responsive to the relative output potentials of the fuel and air cells to interconnect the primary air cell to the drive means for only so long as the fuel cell potential remains below a certain level and is responsive to a rise thereabove to disconnect said primary cell and reconnect the fuel cell to the drive means, the switching means comprising a pair of diodes, two like electrodes thereof being commonly connected to the drive means, and the other electrodes thereof being respectively connected to said primary air cell and the fuel cell, means for sensing increasing alkalinity of said electrolyte during operation of the primary air cell, means responsive to said sensing means to supply an acid to said electrolyte to control the pH of the electrolyte to a desired level, and means for varying the amount of electrical power supplied from said power source to said drive means thereby to control the speed of the vehicle.

2. A system as set forth in claim 1 wherein the sensing means is a coulometer which indirectly senses the increasing alkalinity of the electrolyte as a function of the elapsed time of operation of said primary air cell.

3. A system as set forth in claim 1 wherein the sensing means is a pH meter.

4. A system as set forth in claim 1 wherein the anode of the primary cell comprises magnesium.

5. A system as set forth in claim 4 wherein the primary cell utilizes a liquid electrolyte and the anode thereof is encompassed by a fabric envelope permeable to the passage of electrolyte but substantially impermeable to the passage of magnesium hydroxide formed at the anode as an electrolytic reaction product during operation of the primary air cell.

6. A system as set forth in claim 5 which further includes a reservoir for said electrolyte and means responsive to a decrease in electrolyte level in said primary air cell to replenish the electrolyte therein from said reservoir.

7. A system as set forth in claim 1 which further includes solid-state means for controlling the supply of electric power to said drive means.

8. A system as set forth in claim 1 in which the electrolyte is an aqueous solution of sodium chloride.