Hybrid system for a powertrain and hydraulic system

• US 7,980,073 B2
• Filed: 05/08/2008
• Issued: 07/19/2011
• Est. Priority Date: 05/08/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Jensen, Jeffrey Edward
• Primary Examiner(s): Lazo; Thomas E
• Application Number:
  US12/149,806
• Publication Number:
  US 20090277168A1
• Time in Patent Office: 1,167 Days
• Field of Search: 604/14, 604/36, 604/84, 374/66
• US Class Current: 60/414
• CPC Class Codes: B60K 2025/026 by a hydraulic transmission
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/19 for achieving enhanced acceleration
• CPC Class Codes: B60Y 2200/14 Trucks; Load vehicles, Busses
• CPC Class Codes: B60Y 2200/415 Wheel loaders
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: E02F 9/2091 Control of energy storage means for electrical energy, e.g. battery or capacitors energy recovery arrangements in hydraulic or pneumatic drives E02F9/2217
• CPC Class Codes: E02F 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: F15B 21/14 Energy-recuperation means
• CPC Class Codes: F15B 2211/20523 Internal combustion engine
• CPC Class Codes: F15B 2211/20538 constant capacity
• CPC Class Codes: F15B 2211/3059 having multiple valves for multiple output members
• CPC Class Codes: F15B 2211/315 characterised by the connections of the valve or valves in the circuit
• CPC Class Codes: F15B 2211/7053 Double-acting output members
• CPC Class Codes: F15B 2211/7058 Rotary output members
• CPC Class Codes: F15B 2211/7135 Combinations of output members of different types, e.g. single-acting cylinders with rotary motors
• CPC Class Codes: F15B 2211/761 Control of a negative load, i.e. of a load generating hydraulic energy
• CPC Class Codes: F15B 2211/88 Control measures for saving energy
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A hybrid system for a machine is disclosed. The system has a pump configured to generate fluid flow within a hydraulic system and a first actuator actuated by fluid pressurized by the pump. The system also has a first motor configured to be selectively actuated by pressurized fluid directed from the first actuator by an external load and directed to the first motor by a first control valve. The system further has a first generator configured to be actuated by the first motor and a power source configured to actuate the pump. The system also has a powertrain including a first driveshaft and at least one traction device, the powertrain configured to transfer kinetic energy from the traction device to the first driveshaft during deceleration of the machine. The system further has a second generator configured to be selectively actuated by the kinetic energy transferred by the powertrain.

Claims

1. A hybrid system for a machine, comprising:

a pump configured to generate fluid flow within a hydraulic system;

a first actuator actuated by fluid pressurized by the pump;

a first motor configured to be selectively actuated by pressurized fluid directed from the first actuator by an external load and directed to the first motor by a first control valve;

a first generator configured to be actuated by the first motor;

a power source configured to actuate the pump and a powertrain, the powertrain including a first driveshaft and at least one traction device, and the powertrain configured to transfer kinetic energy from the traction device to the first driveshaft during deceleration of the machine; and

a second generator configured to be selectively actuated by the kinetic energy transferred by the powertrain.

2. The hybrid system of claim 1, further including an electrical storage unit for storing electrical energy transferred from the first and second generators, the electrical storage unit configured to selectively power a second motor using electrical energy transferred from the first and second generators.

3. The hybrid system of claim 2, wherein the second generator and the second motor are a single unit.

4. The hybrid system of claim 1, wherein the external load is the weight of a tool of the machine.

5. The hybrid system of claim 1, further including an inverter/converter for converting electrical energy transferred from the first and second generators.

6. The hybrid system of claim 1, further including a second actuator configured to be actuated by the pump.

7. The hybrid system of claim 1, further including a transfer gear configured to transfer the kinetic energy from the powertrain to actuate the second generator.

8. The hybrid system of claim 7, further including a shaft operably connecting the transfer gear to the second generator.

9. The hybrid system of claim 8, wherein the shaft is configured to selectively transfer the kinetic energy to the second generator.

10. A hydraulic system for a hybrid machine, comprising:

a pump configured to generate fluid flow within a hydraulic system;

first, second, third, and fourth control valves, each having a plurality of positions for directing fluid;

a first actuator configured to be actuated by fluid pumped by the pump and directed to the first actuator via the first and second control valves;

a second actuator and a third actuator configured to be actuated by fluid pumped by the pump and directed to the second actuator and the third actuator via the third and fourth control valves;

a first motor configured to be selectively actuated by pressurized fluid directed from the first actuator by an external load and directed to the first motor via the second control valve;

a second motor configured to be selectively actuated by pressurized fluid directed from the second actuator and the third actuator by a load and directed to the second motor by the fourth control valve;

a first generator actuated by the first motor; and

a second generator actuated by the second motor.

11. The hydraulic system of claim 10, further including a check valve associated with the first control valve and configured to prevent flow from the first control valve to the pump.

12. The hydraulic system of claim 10, further including an electrical storage unit for storing electrical energy transferred from the first generator and the second generator.

13. The hydraulic system of claim 12, further including a powertrain driven by a power source, the powertrain being configured to selectively drive a third generator, the third generator being configured to direct electrical energy produced by the third generator to the electrical storage unit.

14. The hydraulic system of claim 10, wherein the first control valve and the third control valve are configured to operate in at least three different positions.

15. A machine, comprising:

at least one pump configured to generate fluid flow within a hydraulic system, the at least one pump actuated by a power source;

a plurality of control valves configured to direct the pressurized fluid within the hydraulic system;

a plurality of actuators actuated by the at least one pump;

a first motor actuated by pressurized fluid selectively directed from the plurality of actuators by an external load and directed to the first motor by the plurality of control valves;

a first generator actuated by the first motor;

a powertrain actuated by the power source, the powertrain having a plurality of driveshafts and a plurality of traction devices, the powertrain configured to transfer kinetic energy from the plurality of traction devices to the plurality of driveshafts during deceleration of the machine;

a transfer gear configured to transfer kinetic energy from the powertrain to actuate a second generator; and

an electrical storage unit for storing electrical energy transferred from the first generator and the second generator, the electrical storage unit configured to selectively power a second motor for selectively actuating the plurality of driveshafts.

16. The machine of claim 15, wherein the electrical storage unit selectively powers the second generator using electrical energy transferred from the first generator and the second generator.

17. The machine of claim 15, further including at least one inverter/converter for converting electrical energy transferred from the first generator.

18. The machine of claim 15, wherein the electrical storage unit is configured to selectively power the second generator with converted electrical energy, the second generator configured to actuate the plurality of driveshafts.

19. The machine of claim 15, wherein the plurality of driveshafts includes the transfer gear.

20. The machine of claim 19, further including a shaft operably connecting the transfer gear to the second generator, the shaft configured to actuate the second generator using the kinetic energy transferred by the powertrain.