Patent classifications
E02F9/2075
Hydraulic work machine
This invention is a hydraulic work machine having an electric assist motor coupled to an engine and a hydraulic pump, in the hydraulic work machine of which, a rotational speed and torque of the engine are controlled so that an operating point of the engine moves along a predetermined route for yielding a combustion state of the engine under a transient state that the engine changes in speed and torque. A target speed and torque of the engine 7 are set so that the rotational speed and torque of the engine 7 will change along a predetermined route F in a running region of the engine, respective rates of change of the target rotational speed and torque of the engine 7 are limited, and the engine 7 is controlled to yield the target engine speed. In addition, torque of the assist motor 10 is controlled to yield the target torque of the engine.
LIQUID-PRESSURE DRIVING SYSTEM
An oil-pressure driving system includes a variable displacement oil-pressure pump, tilting angle adjuster, electric motor, and control device. In the control device, a target assist torque calculating portion calculates a target assist torque, a first torque limiting portion limits the target assist torque to an output value that is a virtual limit value or less, and a drive control portion controls the electric motor such that the electric motor outputs a command torque corresponding to the output value. Further, in the control device, a torque deficiency calculating portion calculates a torque deficiency by subtracting the output value from the target assist torque, a tilting angle calculating portion calculates a tilting angle command value by which the output torque of the oil-pressure pump is reduced by the torque deficiency, and a tilting angle control portion outputs a tilt signal corresponding to the tilting angle command value to the tilting angle adjuster.
Control Apparatus for Hybrid Construction Machine
A control apparatus for a hybrid construction machine which can continue filter regeneration without impairing the operability as far as possible irrespective of a condition of a machine body or a power storage device is provided. The control apparatus for a hybrid construction machine includes an engine, a motor generator driven by the engine and capable of generating electric power, a hydraulic pump driven by total torque of the engine and the motor generator, a power storage device, an inverter, a filter that collects a particulate material in exhaust gas of the engine, and a control section that outputs a command signal for controlling powering operation or regeneration operation of the motor generator. The control apparatus further includes a powering operation limitation section that inputs thereto an ordinary torque command for the motor generator calculated by a torque command value calculation section and a demand signal for regeneration of the filter decided by a filter regeneration decision section and calculates the command signal in response to the input signals. The powering operation limitation section calculates, when the demand signal for regeneration of the filter is available, a command signal for limiting the powering operation of the motor generator.
Control system for hydraulic system and method for recovering energy and leveling hydraulic system loads
A control system for a hydraulic system including an accumulator and a hydraulic transformer coordinates flow sharing within the hydraulic system. The hydraulic transformer includes first and second variable displacement pump/motor units mounted on a rotatable shaft. The rotatable shaft has an end adapted for connection to a first external load. The first variable displacement pump/motor unit includes a first side that fluidly connects to a pump and a second side that fluidly connects to a tank. The second variable displacement pump/motor unit includes a first side that fluidly connects to the accumulator and a second side that fluidly connects with the tank. A second external load may be hydraulically connected to the hydraulic system. Energy may be transferred to/from the pump, the accumulator, the first external load, and/or the second external load, as directed by the control system.
Work vehicle and control method for work vehicle
A power transmission device of a work vehicle includes a generator, a motor, and an energy storage unit. The energy storage unit stores electricity generated by the generator. A forward/backward travel switch operation device receives an instruction for forward or backward travel from an operator. A vehicle speed detection unit detects the speed of the vehicle. A control unit includes an energy management requirement determination unit. The energy management requirement determination unit determines, on the basis of the difference between a target electricity storage amount and a current electricity storage amount in the energy storage unit, the energy management required power required by the power transmission device for charging the energy storage unit. The energy management requirement determination unit increases the target electricity storage amount when a first travel direction according to the instruction and a second travel direction determined from the vehicle speed are different.
Mining machine and energy storage system for same
A mobile mining machine includes a plurality of traction elements, a plurality of motors, a power source in electrical communication with the plurality of motors, and an energy storage system in electrical communication with the plurality of motors and the power source. Each of the motors is coupled to an associated one of the plurality of traction elements. Each of the motors is driven by the associated traction element in a first mode, and drives the associated traction element in a second mode. The energy storage system includes a shaft, a rotor secured to the shaft, a stator extending around the rotor, and a flywheel coupled to the shaft for rotation therewith. In the first mode, rotation of the motors causes rotation of the flywheel to store kinetic energy. In the second mode, rotation of the rotor and the flywheel discharges kinetic energy to drive the motors.
Electric drivetrain system and method having a single speed ratio direct drive
A machine having a series electric drivetrain system includes an engine to provide mechanical energy to an electric generator, the electric generator able to convert the mechanical energy received from the engine into electrical energy, the electric generator including an input shaft extending through the electric generator, a rotor to rotate on the input shaft, and the input shaft is able to rotate an input gear, an idler gear, a pump drive gear, and a rotor gear, a motor to receive the electrical energy and to produce a rotational output, a single speed ratio direct drive to transfer the rotational output of the motor to a torque output to deliver to a drive shaft, and power electronics to control the electrical energy between the electric generator and the motor and to regulate the rotational output of the motor.
Working Machine
An electric or hybrid working machine includes a ground engaging structure, an electrical source of power, an electric motor arrangement, one or more hydraulically actuated devices, and a hydraulic pump configured to supply hydraulic fluid to the one or more hydraulically actuated devices. The working machine also includes a transmission operable to transmit drive from the electric motor arrangement to the ground engaging structure and the hydraulic pump. The transmission has a first input member connected to a first electric motor, a drive train comprising a first input gear connected to the first input member, and a coupling device connected between the first input member and the first input gear to selectively adjust transmission of drive to the hydraulic pump and the ground engaging structure.
Construction Machine
An electricity storage device (20) includes voltage detectors (25A) to (25C) detecting cell voltages (VcA) to (VcC) and a controller (26) controlling the cell voltages (VcA) to (VcC). The controller (26) includes a balancing control section (27) performing balancing control reducing deviations of the cell voltages (VcA) to (VcC), a maximum cell voltage calculating section (28) calculating a maximum cell voltage (Vmax) in the cell voltages (VcA) to (VcC), a minimum cell voltage calculating section (29) calculating a minimum cell voltage (Vmin) in the cell voltages (VcA) to (VcC), and an abnormality detecting section (34) detecting an abnormality of the electricity storage device (20) in accordance with whether or not a differential voltage (ΔV) between the maximum cell voltage (Vmax) and the minimum cell voltage (Vmin) is within a range of a reference differential voltage (ΔVstd1) calculated based on a history of the balancing control performed.
ELECTRIC BRAKING POWER USED FOR BATTERY REGENERATION IN A MOBILE WORK MACHINE
The available power surge capacity of a battery is detected. The available steady state regeneration energy capacity of the battery is also detected. The available battery generation power, available from an electric motor, is detected as well. The generation power available from the electric motor is applied to regenerate (or recharge) the battery based upon the available power surge capacity, and the available steady state capacity of the battery.