POWER TRANSMISSION DEVICE AND HYBRID CONSTRUCTION MACHINE PROVIDED THEREWITH

• US 20150090506A1
• Filed: 03/06/2013
• Published: 04/02/2015
• Est. Priority Date: 03/26/2012
• Status: Active Grant

• Current Assignee: Kobelco Construction Machinery Company Limited (Kobe Steel Limited)
• Original Assignee: Kobelco Construction Machinery Company Limited (Kobe Steel Limited)
• Inventors: Hirozawa, Mitsunori
• Granted Patent: US 9,637,890 B2
• Time in Patent Office: Days
• US Class Current: 180/53.8
• CPC Class Codes: B60K 6/22 characterised by apparatus, components or means specially adapted for HEVs
• CPC Class Codes: B60K 6/30 characterised by chargeable mechanical accumulators, e.g. flywheels
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/103 of fluid type
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: E02F 9/202 Mechanical transmission, e.g. clutches, gears clutches per se F16D, gears per se F16H
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: F02D 29/04 peculiar to engines driving pumps
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• 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 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

A configuration is provided to directly utilize the power of an engine as the power of a hydraulic pump, and to efficiently perform power generation and engine assist. The configuration is provided with an engine; a generator which is configured to generate electric power by an operation of the generator using the power of the engine; a battery which is configured to store the electric power generated by the generator; a motor which is configured to be operated by the power of the engine and by the electric power of the battery; a hydraulic pump connected to the motor so as to be driven by operation of the motor; and a power divider connected to the engine, the generator, and the motor so that the power of the engine is distributed to the generator and to the motor.

Claims

1. A power transmission device to be provided to a hybrid construction machine, comprising:

an engine;

a generator which is configured to generate electric power by operation of the generator using power of the engine;

a battery which is configured to store the electric power generated by the generator;

a motor which is configured to be operated by the power of the engine and by the electric power of the battery;

a hydraulic pump connected to the motor so as to be driven by operation of the motor; and

a power divider connected to the engine, the generator, and the motor so that the power of the engine is distributed to the generator and to the motor.

2. The power transmission device according to claim 1, wherein

the power divider includes a variable speed mechanism which changes the number of rotations of the engine so that the number of rotations of the generator is larger than the number of rotations of the motor.

3. The power transmission device according to claim 2, wherein

the variable speed mechanism is configured to transmit the power of the engine to the generator in a state that the number of rotations of the engine is increased, and

the power divider is configured to transmit the power of the engine to the motor in a state that the number of rotations of the engine is maintained.

4. The power transmission device according to claim 1, further comprising:

a clutch which is switchable between a connected state that a power transmission route between the power divider and the motor is connected, and a disconnected state that the power transmission route between the power divider and the motor is disconnected;

a charge amount detector which is configured to detect an amount of charge of the battery; and

power control means which switches the clutch to the disconnected state, allows the motor to operate by the electric power of the battery, and further allows the engine to stop, when the amount of charge of the battery detected by the charge amount detector is not smaller than a predetermined value.

5. The power transmission device according to claim 4, wherein

the power control means includes:

a clutch switching member which switches the clutch between the connected state and the disconnected state;

a motor controller which controls driving of the motor;

an engine controller which controls driving of the engine; and

a power controller which outputs a control command to the clutch switching member, the motor controller, and the engine controller, based on a detection result from the charge amount detector.

6. A hybrid construction machine, comprising:

a hydraulic actuator; and

the power transmission device of claim 1 including the hydraulic pump which drives the hydraulic actuator.