A work machine includes an engine, a motor-generator, a battery, a power detector, a temperature detector, and circuitry. The engine is to move the work machine. The motor-generator is to move the work machine and to generate electric power. The battery is to store the electric power generated by the motor-generator. The power detector is to detect a charge level of the electric power stored in the battery. The temperature detector is to detect a temperature of the battery. The circuitry is configured to control the motor-generator in accordance with the charge level selectively to move the work machine or to generate electric power when the temperature of the battery detected by the temperature detector is within a temperature range.

A work machine includes a machine body, an engine, a rotary electrical device, and a battery. The engine is provided on the machine body to move the machine body. The rotary electrical device is provided on the machine body to move the machine body and to generate electric power. The battery is to be charged by the rotary electrical device and to discharge electric power to the rotary electrical device to move the machine body. The battery being is provided adjacent to the engine.

A work machine includes a machine body, an engine, a rotary electrical device, and an electric power controller. The engine is provided on the machine body to move the machine body. The rotary electrical device is provided on the machine body to move the machine body. The electric power controller is disposed above the rotary electrical device in a height direction along a height of the work machine to control the rotary electrical device.

A mobile apparatus includes a main frame, an operating arm connected to the main frame, drive means configured to drive displacing means of the mobile apparatus, such as one or more wheels or tracks, drive means configured to drive the operating arm and a control system, connected to operating instruments for a driver, for controlling the drive means. The drive means for the displacing means includes an electric motor such that the drive of the displacing means is substantially electrical.

A motor-generator (27) is connected mechanically to an engine (21) and a hydraulic pump (23). The hydraulic pump (23) delivers pressurized oil to cylinders (12D) to (12F) in a working mechanism (12), a traveling hydraulic motor (25) and a revolving hydraulic motor (26). The revolving hydraulic motor (26) drives a revolving device (3) in cooperation with a revolving electric motor (33). An HCU (36) reduces outputs of the revolving electric motor (33), the revolving hydraulic motor (26), the boom cylinder (12D) and the like such that a ratio of a revolving speed of an upper revolving structure (4) and a movement speed of raising a boom (12A) is held to a ratio in a normal mode (NMODE) at the time of performing a compound movement of a revolving movement and a boom-raising movement in a low speed mode (LSMODE).

A control unit embedded in a work vehicle includes a clutch controlling unit and a motor controlling unit. The clutch controlling unit is configured to disengage a first clutch in a condition that the first clutch is engaged and a second clutch is disengaged, when a first moving direction inputted through a forward/rearward movement switch operating device as an instruction of the operator and a second moving direction determined based on a vehicle speed detected by a vehicle speed detecting unit are different from each other, and in addition, when and the vehicle speed falls in a preliminarily set first range. The motor controlling unit is configured to control a motor to reduce a relative rotational speed of the second clutch after the first clutch is disengaged.

A pump that supplies hydraulic oil to a boom cylinder and a turning hydraulic motor; a regenerative hydraulic motor is coupled to the pump and to which the hydraulic oil discharged from the boom cylinder at a time of boom lowering and/or the hydraulic oil discharged from the turning hydraulic motor at a time of turning deceleration is/are led; an engine drives the pump; an alternator mounted to the engine and operable to rotate an output shaft of the engine when electric power is supplied to the alternator; an electrical storage device connected to the alternator; a power converter interposed between the alternator and the electrical storage device; and a controller that switches the power converter to either a servo-on state or a servo-off state and that controls the power converter either in a charging mode or in a discharging mode when switching the power converter to the servo-on state.

A work machine including a prime mover, an electric motor, an electric motor fluid circuit, a transmission fluid circuit, a hydraulic circuit, a cooling circuit, a pump, and a controller. The electric motor may supply a portion of power of the prime mover. The electric motor fluid circuit may be adapted to remove waste heat from the electric motor. The transmission fluid circuit may be adapted to lubricate a moving part of a transmission powered by the prime mover. The hydraulic circuit may be adapted to transmit power from the prime mover to a moving component of the work machine. The cooling circuit may be absorbing waste heat from one or more of the electric motor fluid circuit, the transmission fluid circuit, and the hydraulic circuit. The control may be adapted to control diversion of a portion of waste heat from the cooling circuit to a portion of the cab.

A speed-changing device (21) is provided with an input shaft (22), an output shaft (23), a planetary gear mechanism (29), a first variator (33), a second variator (34), and a controller (25). The planetary gear mechanism (29) is configured to include a carrier (29A) connected to the input shaft (22), a first sun gear (29B) connected to the first variator (33), and a second sun gear (29C) connected to the output shaft (23). The second variator (34) transmits power transmitted from the first variator (33) to the output shaft (23), or transmits power transmitted from the output shaft (23) to the first variator (33). The controller (25) changes the rotation speed of the first variator (33), thereby changing the rotation speed of the output shaft (23) in relation to the rotation speed of the input shaft (22).

To provide a hybrid wheel loader capable of reliably detecting a short-circuited state of a synchronous generator driven by a drive source. The present invention is provided with an MG 4 being a synchronous generator driven as an electric generator by an engine and operated as a motor by the electric power supplied from an electrical storage device 9, an MG inverter 5 having a motor current sensor 5d for detecting motor current flowing through the MG 4 and semiconductor switches 5a, 5b, and an HCU 10 for detecting a short-circuited state of the MG 4, wherein the HCU 10 determines that the MG 4 is in a short-circuited state when the semiconductor switches 5a, 5b of the MG inverter 5 are in an OFF state at gates and when the motor current detected by the motor current sensor 5d is equal to or greater than a specified threshold value.