Four-wheel drive assist for electric machines

• US 6,892,846 B2
• Filed: 04/30/2001
• Issued: 05/17/2005
• Est. Priority Date: 05/02/2000
• Status: Expired due to Term

• Current Assignee: JLG Industries Incorporated (Oshkosh Corporation)
• Original Assignee: JLG Industries Incorporated (Oshkosh Corporation)
• Inventors: Mellot, Lex A., Puszkiewicz, Ignacy
• Primary Examiner(s): Morris, Lesley D.
• Assistant Examiner(s): Winner, Tony
• Application Number:
  US10/275,003
• Publication Number:
  US 20040074687A1
• Time in Patent Office: 1,478 Days
• Field of Search: 180/197, 180/65.2, 180/242, 180/243, 180/305, 180/308
• US Class Current: 180/243
• 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 17/10 of fluid gearing of fluid clutches B60K17/02
• CPC Class Codes: B60K 17/356 having fluid or electric motor, for driving one or more wheels disposition of motor in, or adjacent to, traction wheel B60K7/00
• CPC Class Codes: B60K 2007/0092 the motor axle being coaxial to the wheel axle
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60K 6/00 Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units arrangement or mounting in vehicles of electrical gearing, in which an electrical machine serves only as reduction gearing and not as the prime mover and in which no electrical storing means are used B60K17/12; control and regulation of purely electrical prime movers B60L; prime-movers comprising electrical and internal combustion motors in a common engine block or housing per se F02B65/00; electric motors or motor-generators used for starting the combustion engine F02N11/04; electric motors for synchronising gearing F16H3/12 Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60K 7/0015 the motor being hydraulic
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2220/20 DC electrical machines
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 2240/24 Steering angle
• CPC Class Codes: B60L 2240/30 Parking brake position
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/461 Speed
• CPC Class Codes: B60L 2240/465 : Slip
• CPC Class Codes: B60L 2260/28 : Four wheel or all wheel drive
• CPC Class Codes: B60L 3/102 : of individual wheels
• CPC Class Codes: B60L 3/106 : for maintaining or recovering the adhesion of the drive wheels
• CPC Class Codes: B60L 50/52 : characterised by DC-motors
• 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 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y10S 903/902 : Prime movers comprising electrical and internal combustion motors

Abstract

A four-wheel drive assist for electric machines includes an electric drive system for driving wheels at a non-steering end and a selectively operable hydraulic system for driving wheels at a steering end. A controller controls the operation of the drive system according to operator selection and/or by detecting slipping of the electric drive system. Preferably, at least one hydraulically driven operating arm, including boom functions, lift platform, etc., is driven by the same hydraulic pump that drives the steering end hydraulic system. The machine thus is capable of effecting four-wheel drive when necessary, while operating as efficiently as a conventional two-wheel drive full electric machine when the four-wheel drive system is not engaged.

Claims

1. An electric motor driven lift machine comprising:

a vehicle chassis supporting four wheels and at least one hydraulically driven operating arm;

at least one electric motor coupled with a first set of the plurality of wheels for driving the first set of the plurality of wheels;

at least one hydraulic motor coupled with a second set of the plurality of wheels for selectively driving the second set of the plurality of wheels, wherein the first set and the second set of the plurality of wheels each comprises two of the four wheels, the electric motor driven lift machine including two hydraulic motors respectively coupled with each of the second set of the plurality of wheels;

a hydraulic pump driven by a pump motor and coupled with a source of hydraulic fluid, the hydraulic pump being in fluid communication with the at least one hydraulic motor and the at least one hydraulically driven operating arm, wherein the pump motor is separate from the at least one electric motor;

a flow divider in fluid communication with the hydraulic pump, the flow divider dividing hydraulic fluid flow between each of the second set wheels of the plurality of wheels; and

a traction sensor that detects whether one of the wheels in the second set of the plurality of wheels loses traction, the traction sensor communicating with the flow divider, wherein the flow divider applies a higher pressure to the other of the second set wheels of the plurality of wheels according to a signal from the traction sensor.

2. An electric motor driven lift machine according to claim 1, wherein the first set of the plurality of wheels comprises non-steering wheels of the machine, and wherein the second set of the plurality of wheels comprises steering wheels of the machine.

3. An electric motor driven lift machine comprising:

a vehicle chassis supporting four wheels and at least one hydraulically driven operating arm;

at least one electric motor coupled with a first set of the plurality of wheels for driving the first set of the plurality of wheels;

at least one hydraulic motor coupled with a second set of the plurality of wheels for selectively driving the second set of the plurality of wheels, wherein the first set and the second set of the plurality of wheels each comprises two of the four wheels, the electric motor driven lift machine including two hydraulic motors respectively coupled with each of the second set of the plurality of wheels;

a hydraulic pump driven by a pump motor and coupled with a source of hydraulic fluid, the hydraulic pump being in fluid communication with the at least one hydraulic motor and the at least one hydraulically driven operating arm, wherein the pump motor is separate from the at least one electric motor; and

a flow divider in fluid communication with the hydraulic pump, the flow divider dividing hydraulic fluid flow between each of the second set wheels of the plurality of wheels, wherein the flow divider is hydraulically disposed between the hydraulic pump and a pair of directional control valves respectively coupled with each of the hydraulic motors.

4. An electric motor driven lift machine comprising:

a vehicle chassis supporting a plurality of wheels and at least one hydraulically driven operating arm;

at least one electric motor coupled with a first set of the plurality of wheels for driving the first set of the plurality of wheels;

at least one hydraulic motor coupled with a second set of the plurality of wheels for selectively driving the second set of the plurality of wheels;

a hydraulic pump driven by a pump motor and coupled with a source of hydraulic fluid, the hydraulic pump being in fluid communication with the at least one hydraulic motor and the at least one hydraulically driven operating arm, wherein the pump motor is separate from the at least one electric motor; and

a slip sensor coupled with the first set of the plurality of wheels, the slip sensor detecting a slipping condition of the first set of the plurality of wheels and activating the hydraulic pump upon a slipping detection.

5. An electric motor driven lift machine according to claim 4, wherein the slip sensor comprises an RPM sensor.

6. An electric motor driven lift machine comprising:

a vehicle chassis supporting a plurality of wheels and at least one hydraulically driven operating arm;

at least one electric motor coupled with a first set of the plurality of wheels for driving the first set of the plurality of wheels;

at least one hydraulic motor coupled with a second set of the plurality of wheels for selectively driving the second set of the plurality of wheels;

a hydraulic pump driven by a pump motor and coupled with a source of hydraulic fluid, the hydraulic pump being in fluid communication with the at least one hydraulic motor and the at least one hydraulically driven operating arm, wherein the pump motor is separate from the at least one electric motor; and

an operator actuated switch coupled with the hydraulic pump, the switch activating the hydraulic pump.

7. An electric motor driven machine comprising:

a vehicle chassis supporting a plurality of wheels;

at least one electric motor coupled with a first set of the plurality of wheels for driving the first set of the plurality of wheels;

at least one hydraulic motor coupled with a second set of the plurality of wheels for selectively driving the second set of the plurality of wheels;

a hydraulic pump driven by a pump motor and coupled with a source of hydraulic fluid, the hydraulic pump being in fluid communication with the at least one hydraulic motor, wherein the pump motor is separate from the at least one electric motor; and

a slip sensor coupled with the first set of the plurality of wheels, the slip sensor detecting a slipping condition of the first set of the plurality of wheels and communicating the slipping condition to the hydraulic pump to activate the hydraulic pump.

8. An electric motor driven machine according to claim 7, further comprising an operator actuated switch coupled with the hydraulic pump, the switch activating the hydraulic pump.

9. An electric motor driven machine according to claim 7, wherein the vehicle chassis supports four wheels, and wherein the first set and the second set of the plurality of wheels each comprises two of the four wheels, the electric motor driven machine including two hydraulic motors respectively coupled with each of the second set of the plurality of wheels.

10. An electric motor driven machine according to claim 9, wherein the first set of the plurality of wheels comprises non-steering wheels of the machine, and wherein the second set of the plurality of wheels comprises steering wheels of the machine.

11. An electric motor driven machine according to claim 9, further comprising a flow divider in fluid communication with the hydraulic pump, the flow divider dividing hydraulic fluid flow between each of the second set wheels of the plurality of wheels.

12. An electric motor driven machine according to claim 11, further comprising a traction sensor that detects whether one of the wheels in the second set of the plurality of wheels loses traction, the traction sensor communicating with the flow divider, wherein the flow divider applies a higher pressure to the other of the second set wheels of the plurality of wheels according to a signal from the traction sensor.

13. An electric motor driven machine according to claim 11, wherein the flow divider is hydraulically disposed between the hydraulic pump and a pair of directional control valves respectively coupled with each of the hydraulic motors.

14. A method of operating an electric motor driven lift machine, the machine including a vehicle chassis supporting a plurality of wheels and at least one hydraulically driven operating arm, at least one electric motor coupled with a first set of the plurality of wheels, at least one hydraulic motor coupled with a second set of the plurality of wheels, and a hydraulic pump driven by a pump motor and coupled with a source of hydraulic fluid, the hydraulic pump being in fluid communication with the at least one hydraulic motor and the at least one hydraulically driven operating arm, wherein the pump motor is separate from the at least one electric motor, the method comprising:

driving the first set of the plurality of wheels with the at least one electric motor;

selectively driving the second set of the plurality of wheels with the at least one hydraulic motor via said hydraulic pump;

detecting a slipping condition of the first set of the plurality of wheels and driving the second set of the plurality of wheels according to the detected first set slipping condition; and

driving the hydraulically driven operating arm according to operator control via said hydraulic pump.

15. A method according to claim 14, wherein the step of selectively driving the second set of the plurality of wheels comprises driving the second set of the plurality of wheels according an operator selected switch.

16. A method of operating an electric motor driven lift machine, the machine including a vehicle chassis supporting a plurality of wheels and at least one hydraulically driven operating arm, at least one electric motor coupled with a first set of the plurality of wheels, at least one hydraulic motor coupled with a second set of the plurality of wheels, and a hydraulic pump driven by a pump motor and coupled with a source of hydraulic fluid, the hydraulic pump being in fluid communication with the at least one hydraulic motor and the at least one hydraulically driven operating arm, wherein the pump motor is separate from the at least one electric motor, wherein the vehicle chassis supports four wheels, and wherein the first set and the second set of the plurality of wheels each comprises two of the four wheels, the electric motor driven lift machine including two hydraulic motors respectively coupled with each of the second set of the plurality of wheels, the method comprising:

driving the first set of the plurality of wheels with the at least one electric motor;

selectively driving the second set of the plurality of wheels with the at least one hydraulic motor via said hydraulic pump;

driving the hydraulically driven operating arm according to operator control via said hydraulic pump; and

detecting whether one of the wheels in the second set of the plurality of wheels loses traction, and applying a higher pressure to the other of the second set wheels of the plurality of wheels according to the traction detection, wherein the step of selectively driving the second set of the plurality of wheels comprises dividing hydraulic fluid flow between each of the second set wheels of the plurality of wheels.

17. A method of operating an electric motor driven lift machine, the machine including a vehicle chassis supporting a plurality of wheels and at least one hydraulically driven operating arm, at least one electric motor coupled with a first set of the plurality of wheels, at least one hydraulic motor coupled with a second set of the plurality of wheels, and a hydraulic pump driven by a pump motor and coupled with a source of hydraulic fluid, the hydraulic pump being in fluid communication with the at least one hydraulic motor and the at least one hydraulically driven operating arm, wherein the pump motor is separate from the at least one electric motor, wherein the vehicle chassis supports four wheels, and wherein the first set and the second set of the plurality of wheels each comprises two of the four wheels, the electric motor driven lift machine including two hydraulic motors respectively coupled with each of the second set of the plurality of wheels, the method comprising:

driving the first set of the plurality of wheels with the at least one electric motor;

selectively driving the second set of the plurality of wheels with the at least one hydraulic motor via said hydraulic pump;

driving the hydraulically driven operating arm according to operator control via said hydraulic pump; and

hydraulically disposing a flow divider between the hydraulic pump and a pair of directional control valves respectively coupled with each of the hydraulic motors, wherein the step of selectively driving the second set of the plurality of wheels comprises dividing hydraulic fluid flow between each of the second set wheels of the plurality of wheels.