DRIVE SYSTEMS

• US 3,799,284 A
• Filed: 10/30/1972
• Issued: 03/26/1974
• Est. Priority Date: 10/30/1971
• Status: Expired due to Term

• Current Assignee: Berkeley Stephens Hender
• Original Assignee: Berkeley Stephens Hender
• Inventors: Hender, Berkeley Stephens
• Primary Examiner(s): Schonberg, David
• Assistant Examiner(s): Smith, Milton L.
• Application Number:
  US05/302,011
• Time in Patent Office: 512 Days
• Field of Search: 180/65R,60,65A,62 74/661,665R,665N,665M,665T,665S,665F,75R,675,843,847,793,665P 318/8,13
• US Class Current: 180/65.25
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 17/043 Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel
• CPC Class Codes: B60K 17/046 with planetary gearing having orbital motion
• CPC Class Codes: B60K 17/145 the electric gearing being disposed in or adjacent to traction wheel
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/383 One-way clutches or freewheel devices
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2220/42 with use of more than one motor
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 2710/06 Combustion engines, Gas turbines
• CPC Class Codes: H02K 7/10 : Structural association with clutches, brakes, gears, pulleys or mechanical starters
• CPC Class Codes: H02K 7/14 : Structural association with mechanical loads, e.g. with hand-held machine tools or fans with fan or impeller for cooling the machine H02K9/06
• CPC Class Codes: H02P 5/685 : electrically connected in series, i.e. carrying the same current
• CPC Class Codes: H02P 5/695 : Differential gearing
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y10S 903/91 : Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/913 : One way

Abstract

A versatile drive system suitable for battery powered electric vehicles or other machinery employs two electric motors driving a respective rotatable element, such as a road wheel, or together driving a single rotatable element. The motors are interconnected through a reversing gear unit. The system includes a simple electrical control circuit, whereby a parameter such as the field of one or both motors is varied in response to an accelerator pedal or other control device, and is also controlled in response to an electrical parameter such as armature current. The motor armatures are connected in series with each other, and the arrangement is such that the motors can run at high speed even while the vehicle is stationary. In addition, the motors can be run up in an off-load condition one at a time, the second motor acting regernatively while the first is running alone. A simple modification in which the system is hybridized with an internalcombustion or other engine, useful for example in vehicles running where exhaust fumes are not objectionable, is also described.

Claims

1. A drive system for driving at least one rotatable element at speeds variable continuously from standstill to maximum, including a first electric motor having a first output shaft, and a second electric motor having a second output shaft, said output shafts being operatively coupled with said at least one rotatable element for driving the same, and said output shafts being coupled with each other through transmission means so arranged as, when said first output shaft is rotated, to permit said second motor to run with rotation of said second output shaft in a direction selectively corresponding to, or reversed with respect to, the direction of rotation of said first output shaft, wherein the system includes control means comprising first Means and second means both arranged for varying a first parameter of a said motor, said first means being responsive to an electrical further parameter of said motors and said second means being controllable independently of said first means, the arrangement being such that appropriate continuous variation of said first parameter can produce accelerating and decelerating torque variation in the second output shaft whilst at least one of the motors is running at a speed independent of the speed of the associated at least one rotatable element.

2. The drive system according to claim 1, wherein said first and second electric motors are connected electrically in series.

3. A drive system according to claim 2, wherein each electric motor has an armature, and said first means of the control means is connected in the motor circuit so as to be responsive to motor armature current constituting said further parameter.

4. A drive system according to claim 2, including electrical switching means in parallel with said second electric motor and arranged to remain closed in response to a condition wherein the second output shaft is rotating in a direction reversed with respect to the direction of rotation of said first output shaft.

5. A drive system according to claim 1, wherein each of said first and second electric motors has a wound armature, said armatures being connected electrically in series.

6. A drive system according to claim 1, wherein said electric motors each has a field, and said control means is connected to said second electric motor so as to vary the field, constituting said first parameter thereof.

7. A drive system according to claim 6, wherein said control means is connected to both of said electric motors so as to vary the fields thereof.

8. A drive system according to claim 7, wherein said control means is connected with a field winding of each of said electric motors, said electric motors being of the separately excited kind.

9. A drive system according to claim 6, wherein said control means is connected with a field winding of said second electric motor, said second electric motor being of the separately excited kind.

10. A drive system according to claim 1, wherein said control means comprise a pulse controller which is common to both said first and second means of the control means.

11. A drive system according to claim 1, wherein said first electric motor is series wound.

12. A drive system according to claim 1, wherein at least one of said electric motors is of a kind having permanent-magnet field excitation.

13. A drive system according to claim 1, wherein each of said first and second electric motors is coupled with a respective at least one said rotatable element through first and second gear means respectively.

14. A drive system according to claim 13, wherein the first and second output shafts are coupled with each other through transmission means comprising at least part of said first and second gear means and means including reversing third gear means coupling an element of said first gear means with an element of said second gear means.

15. A drive system according to claim 14, wherein each of said first and second gear means includes an epicyclic gear arrangement each of which comprises a train of three elements of an epicyclic gear train of four elements, namely a sun wheel;

a planet carrier;

at least one planet wheel engaging the sun wheel and carried by the planet carrier; and

an annular gear ring engaging the planet wheel, the fourth said element of each said gear train being rotatably coupled with an element of said third gear means.

16. A drive system according to claim 1, including a prime mover and releasable coupling means connecting the prime mover to one of said first and second electric motors whereby to transmit driving torque to such motor.

17. A drive system according to claim 16, wherein the prime mover is an internal-combustion engine.

18. An electrically powered vehicle incorporating a drivE system according to claim 1, wherein said rotatable elements are running wheels of the vehicle, each wheel of at least one pair of said wheels being operatively coupled to a respective one of said first and second output shafts, and said second means of the control means being coupled to an accelerating and decelerating control device of the vehicle for actuation thereby.