Abstract: A hybrid work machine includes a turning electric motor configured to turn an upper-part turning body, a hydraulic actuator, and a controller configured to control turning in a state of an independent turning operation by the turning electric motor and in a state of a combined turning operation by the turning electric motor and the hydraulic actuator. The controller is configured to limit the output of the turning electric motor in the state of the independent turning operation after a transition from the state of the combined turning operation to the state of the independent turning operation to an output smaller than the output of the turning electric motor in the state of the independent turning operation other than the state of the independent turning operation after said transition.

Abstract: A shovel includes a boom 4 or an arm 5 driven by a hydraulic oil discharged from a main pump 12. The shovel also includes a pressure sensor 17A which detects an operating condition of the boom 4, an arm angle sensor S1 which detects an arm angle ?, a body stability determining part 300 which determines a body stability degree of the shovel based on the arm angle ? and an operating condition of the boom 4, and a discharge rate controlling part 301 which decreases a horsepower of the main pump 12 if it is determined by the body stability determining part that a body stability degree becomes lower than or equal to a predetermined level.

Abstract: A hybrid work machine includes an engine, a motor generator connected to the engine, an electric energy storage unit configured to store electric power generated by the motor generator, and a control part configured to control driving of the motor generator. The control part is configured to control the driving of the motor generator so that an assist output of the motor generator increases, based on an external condition of the engine.

Abstract: A shovel includes an internal combustion engine, a hydraulic pump connected to the internal-combustion engine, a generator connected to the internal-combustion engine, and a control part that controls the generator. The control part increases an electric generation load of the generator before a hydraulic load of the hydraulic pump increases.

Abstract: An hydraulic shovel according to the present invention includes a lower running body 1, an upper turning body 3 turnably mounted on the lower running body 1, a boom 4 pivotably attached to the upper turning body 3, an arm 5 pivotably attached to the boom 4, a bucket 6 attached to the arm 5, an boom angle sensor S1 which detects a condition of the boom 4, an attachment condition determining part 300 which determines whether the boom 4 is within a predetermined upper working range based on a detection value of the boom angle sensor S1, and an operating condition switching part 301 which switches an operating condition of the hydraulic shovel. The operating condition switching part 301 slows down a movement of the bucket 6 if the attachment condition determining part 300 determines that an attachment is within the predetermined upper working range UWR.

Abstract: A turning control apparatus includes a turning body and a hydraulic motor to turn the turning body. A high-pressure relief circuit relieves hydraulic pressure of a first hydraulic line at a first relief pressure, the first hydraulic line supplying an operating oil to drive the hydraulic motor. A hunting reduction circuit relieves a hydraulic pressure of a second hydraulic line at a pressure lower than the first relief pressure, the second hydraulic line being connected to a deceleration-side hydraulic port from which the operating oil is discharged when the hydraulic motor is being driven. The hunting reduction circuit connected to the deceleration-side hydraulic port is caused to open before an operation lever to operate turning of the turning body returns to a neutral position.

Abstract: A shovel includes an engine; a hydraulic pump driven by the engine; an attachment including a boom, the attachment being driven with hydraulic fluid discharged by the hydraulic pump; a motor generator configured to assist driving by the engine; an electric power accumulating part configured to accumulate electric power generated by the motor generator; a motion state detecting part configured to detect the motion state of the attachment; and an assist control part configured to control the execution of an assist by the motor generator using the electric power accumulated in the electric power accumulating part. The assist control part is configured to cause the motor generator to assist the engine during a boom raising motion after an excavation motion.

Abstract: A hydraulic shovel includes an engine; a hydraulic pump driven by the engine; an excavating attachment which is driven by high oil discharged from the hydraulic pump; a motor generator that assists a power supply of the engine; and an assist control unit that controls the motor generator to assist the engine in a latter part of the excavating operation by the excavating attachment.