ENERGY EFFICIENT ELECTRIC VEHICLE CONTROL SYSTEM

• US 20160152138A1
• Filed: 06/26/2014
• Published: 06/02/2016
• Est. Priority Date: 06/26/2013
• Status: Active Grant

• Current Assignee: Parker Hannifin Manufacturing Limited (Parker-Hannifin Corporation)
• Original Assignee: Parker Hannifin Manufacturing Limited (Parker-Hannifin Corporation)
• Inventors: McCann, Thomas
• Granted Patent: US 9,975,426 B2
• Time in Patent Office: Days
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 2025/106 by fluid means
• CPC Class Codes: B60K 25/10 directly from oscillating movements due to vehicle running motion, e.g. suspension movement resilient suspensions having dampers accumulating utilisable energy, e.g. compressing air, B60G13/14
• CPC Class Codes: B60K 6/12 by means of a chargeable fluidic accumulator
• CPC Class Codes: B60W 2300/12 Trucks; Load vehicles
• CPC Class Codes: B60W 2300/121 Fork lift trucks, Clarks
• CPC Class Codes: B60W 2300/15 Agricultural vehicles
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

An electric vehicle comprises an electrical system and a hydraulic system. The electrical system comprises an electric power supply and an electric motor-generator connected to the drive train of the vehicle. The hydraulic system includes a pump, and a hydraulic actuator. At least one of the electrical system and the hydraulic system includes energy recovery means arranged to convert kinetic energy from the drive train to electrical energy or to convert kinetic energy from the hydraulic actuator into hydraulic pressure respectively. The electrical and hydraulic systems are connected such that the recovered energy may be converted from electrical to hydraulic energy and/or vice versa. The hydraulic system may further include a hydraulic accumulator.

Claims

1. A vehicle comprising

an electrical system comprising an electric power supply and an electric motor-generator connected to the drive train of the vehicle;

and

a hydraulic system including a pump, and a hydraulic actuator;

wherein at least one of the electrical system and the hydraulic system includes energy recovery means arranged to convert kinetic energy from the drive train to electrical energy or to convert kinetic energy from the hydraulic actuator into hydraulic pressure respectively, the electrical and hydraulic systems being connected such that the recovered energy may be converted from electrical to hydraulic energy or vice versa.

2. A vehicle according to claim 1 wherein the hydraulic system further includes a hydraulic accumulator

3. A vehicle according to claim 2 wherein the electric motor-generator is arranged to convert kinetic energy from the drive train to electrical energy and is connected to the hydraulic system such that the recovered electrical energy may be converted to hydraulic power via the pump and stored in the hydraulic accumulator.

4. A vehicle according to claim 3 wherein the electrical power supply is a battery and the recovered electrical energy may be selectively used to charge the battery and/or converted to hydraulic power and stored in the accumulator.

5. A vehicle according to any one of claims 2 to 4 wherein the hydraulic system includes a motor-generator connected to the pump and arranged such that hydraulic power stored in the accumulator may be converted to electrical energy.

6. A vehicle according to claim 5 wherein the electrical energy generated from the stored hydraulic accumulator may be selectively directed to the motor-generator to provide motion to the drive train and/or to charge the battery.

7. A vehicle according to any one of claim 5 or 6 further comprising an inverter drive connected to the motor-generator of the hydraulic system.

8. A vehicle according to any preceding claim further comprising an inverter drive connected to the motor-generator of the electrical system.

9. A vehicle according to any preceding claim wherein the motor-generator of the electrical system is connected to a traction drive, and is configured to apply a braking force to the vehicle and to convert the kinetic energy generated during said braking to electrical energy.

10. A lift truck comprising:

a battery;

an inverter drive electrically connected to the battery and connected to a first motor/generator, a traction drive/brake coupled to the first motor/generator;

a second inverter drive electrically connected to the battery and connected to a second motor/generator; and

a hydraulic pump/motor coupled to the second motor/generator and hydraulically connected to a hydraulic lift circuit including a hydraulic actuator and a hydraulic accumulator;

wherein kinetic energy from the traction drive/brake is converted to electrical energy and selectively stored in the battery or converted into hydraulic power and selectively stored in an accumulator or used to actuate the hydraulic actuator.

11. The lift truck of claim 11, wherein kinetic energy from actuation of the hydraulic actuator is converted to hydraulic power and selectively stored in the accumulator or converted into electrical power and selectively stored in the battery or converted into torque to move the lift truck.

12. A work machine comprising:

a battery;

a first inverter drive electrically connected to the battery and connected to a first motor/generator,

a traction drive coupled to the first motor/generator;

a second inverter drive electrically connected to the battery and connected to a second motor/generator,

a hydraulic pump/motor coupled to the second motor/generator and hydraulically connected to a hydraulic lift circuit including a hydraulic actuator and a hydraulic accumulator;

the traction drive selectively driving the first motor/generator;

the first motor/generator selectively driving the traction drive;

the second motor/generator selectively driving the hydraulic pump/motor;

the hydraulic pump/motor selectively driving the second motor/generator;

the hydraulic actuator selectively driving the hydraulic pump/motor;

the accumulator adapted to receive and store hydraulic pressure from the hydraulic pump/motor or from the hydraulic actuator and to selectively provide hydraulic pressure to the hydraulic actuator or to the hydraulic pump/motor; and

the battery adapted to selectively receive and store electric power from at least one of the motor/generators through at least one of the inverter drives and to selectively provide electric power to at least one of the motor/generators through at least one of the inverter drives.

13. A method of operating the work machine of claim 12, comprising the steps of:

moving the vehicle by the traction drive by selectively utilizing power from the battery, the accumulator, or the hydraulic actuator, alone or in any combination;

operating the hydraulic actuator by selectively utilizing power from the battery, the accumulator, or the traction drive, alone or in any combination.

14. The method of claim 13, wherein the work machine operates in a “

stand by”

mode, wherein the motor/generator is run off of the battery at an optimum speed and torque and the hydraulic pump/motor is used to charge the accumulator.

15. The method of claim 13, wherein the work machine operates in an “

accelerating drive”

mode, wherein the first motor/generator will take power from the battery, the traction drive operation can be assisted by running the hydraulic pump/motor using flow from the accumulator.

16. The method of claim 13, wherein the work machine operates in an “

decelerating drive”

mode, wherein the traction drive will create power by rotating the motor/generator, this power is transferred and stored by the battery or routed to the hydraulic pump/motor to charge the accumulator.

19. The method of claim 13, wherein the work machine operates in a “

lift”

mode, wherein the hydraulic actuator is powered by the accumulator or by the battery or the traction drive.

20. The method of claim 13, wherein the work machine operates in a “

lower”

mode, wherein a lowering speed is set by the second motor/generator, by the load motor if accumulator needs charged and to generate electricity if the accumulator is fully charged.

24. A method of operating the work machine of claim 12, comprising the steps of:

moving the vehicle by the traction drive by selectively utilizing power from the battery, the accumulator, or the hydraulic actuator, alone or in any combination;

operating the hydraulic actuator by selectively utilizing power from the battery, the accumulator, or the traction drive, alone or in any combination.

21. A work machine comprising:

a battery;

an inverter drive electrically connected to the battery and connected to a motor/generator,

a traction drive/brake coupled to the motor/generator;

a hydraulic pump/motor coupled to the motor/generator and hydraulically connected to a hydraulic circuit including a hydraulic actuator and a hydraulic accumulator;

the traction drive selectively driving the motor/generator;

the motor/generator selectively driving the traction drive;

the motor/generator selectively driving the hydraulic pump/motor;

the hydraulic pump/motor selectively driving the motor;

the hydraulic actuator selectively driving the hydraulic pump/motor;

the accumulator adapted to receive and store hydraulic pressure from the pump/motor or from the hydraulic actuator and to selectively provide hydraulic pressure to the hydraulic actuator or to the hydraulic pump/motor; and

the battery adapted to selectively receive and store electric power from the motor/generators through the inverter drive and to selectively provide electric power to the motor/generators through the inverter drive.

22. A method of operating the work machine of claim 21, comprising the steps of:

moving the vehicle by the traction drive by selectively utilizing power from the battery, the accumulator, or the hydraulic actuator, alone or in any combination;

operating the hydraulic actuator by selectively utilizing power from the battery, the accumulator, or the traction drive, alone or in any combination.

23. A work machine comprising:

a battery;

an inverter drive electrically connected to the battery and connected to a motor/generator;

the battery adapted to selectively receive and store electric power from the motor/generator through the inverter drive and to selectively provide electric power to the motor/generator through the inverter drive;

a first hydraulic pump/motor coupled to the motor/generator and hydraulically connected to a hydraulic circuit including a hydraulic actuator, a second hydraulic pump/motor, and a hydraulic accumulator;

the second hydraulic pump/motor coupled a traction drive/brake;

the motor/generator selectively driving the first hydraulic pump/motor;

the first hydraulic pump/motor selectively driving the motor/generator;

the traction drive selectively driving the second hydraulic pump/motor;

the second hydraulic pump/motor selectively driving the traction drive;

the first hydraulic pump/motor selectively driving the second hydraulic pump/motor or providing hydraulic pressure to the hydraulic actuator;

the second hydraulic pump/motor selectively driving the first hydraulic pump/motor or providing hydraulic pressure to the hydraulic actuator;

the hydraulic actuator selectively driving the first hydraulic pump/motor or the second hydraulic pump/motor; and

the accumulator adapted to receive and store hydraulic pressure from the first hydraulic pump/motor, the second hydraulic pump/motor, or from the hydraulic actuator and to selectively provide hydraulic pressure to the hydraulic actuator or to the first hydraulic pump/motor or to the second hydraulic pump/motor.