An opening and closing motion control section controls an optional control valve so as to reduce opening degree of the optional control valve in a case where a first opening reduction condition is satisfied that a slewing operation detection section detects an operation amount equal to or more than a reference operation amount set in advance so that the reference operation amount is larger than a minimum operation amount of a slewing operation member for causing slewing motion of an upper slewing body and that an optional operation detection section detects operation received by an optional operation member.

The present invention relates to a mobile work machine, in particular to an excavator, that comprises an undercarriage having a tracked chassis, a rail mounting, or a wheeled chassis, a superstructure having an attachment fastened thereto, and a slewing ring that rotatably connects the undercarriage and the superstructure to one another. The work machine is characterized by a decentralized energy supply and/or by a decentralized supply network, preferably a DC supply network, and a slip ring for transferring electrical energy between the superstructure and the undercarriage.

A work machine includes: a first posture detection device which detects a posture of an upper slewing body with respect to a lower travelling body; a second posture detection device which detects a posture of a blade; a laser beam receiver which is provided to the upper slewing body and can receive a laser beam emitted from a laser beam emitter; and a calculation unit which calculates a height position of a cutting edge of the blade with respect to a surface to be constructed. The calculation unit calculates the height position of the cutting edge of the blade with respect to the surface to be constructed based on a laser beam receiving position where the laser beam is received by the laser beam receiver, a posture of the upper slewing body with respect to the lower travelling body, and a posture of the blade.

A turning control apparatus, for a turning-type working machine, includes: a target stop position setting unit setting the target stop position of the turning body and a turning command unit. The target stop position setting unit includes an image taking device, an image processing device forming an overhead view image of the work machine and surrounding objects based on the taken image; an image display command unit making a target stop position setting image including the overhead view image be displayed on a display screen of the image display device, a setting operation member to which a position setting operation for setting a target stop position with reference to the position of the image of the work machine and surrounding objects included in the overhead view image is applied, and a target stop position determination unit that determines a target stop position based on the position setting operation.

A rotary drive system includes an electric motor, a speed reducer, and a lubricating oil-circulating unit. The electric motor has an electric motor casing forming a first accommodating space and a communication hole communicating downward. The speed reducer has a speed reducer casing forming a second accommodating space communicating with the first accommodating space through the communication hole. The lubricating oil-circulating unit has a lubricating oil flow path and a lubricating oil pump. The lubricating oil flow path connects the first accommodating space and the second accommodating space at the outside. The lubricating oil pump pumps lubricating oil from the second accommodating space side to the first accommodating space side.

An electric motor includes a rotor having a rotary shaft rotating around a vertically extending axis and a rotor core fixed to an outer peripheral surface of the rotary shaft, a stator surrounding the rotor core from an outer peripheral side, a lower bottom portion as a partition wall partitioning a first space where the rotor and the stator are disposed and a lubricating oil is supplied from an outside, a storage portion configured to store the lubricating oil supplied into the first space, a brake mechanism as a drive unit discharging the lubricating oil inside the storage portion into the first space, and sliding portions into each of which the lubricating oil discharged from the inside of the storage portion is introduced.

This construction machine comprises: an attitude sensor that detects the current attitude of an upper turning body; a reference angular acceleration calculation unit that calculates a reference angular acceleration to be generated when an electric turning motor is driven by a torque command value generated according to the operation amount of an operation part; a reference gravity torque calculation unit that, on the basis of the current attitude and the deviation between an actual angular acceleration which is obtained from a rotation speed and the reference angular acceleration, calculates a reference gravity torque which is a torque component to be generated about the turning axis by the gravity in the reference attitude; a gravity compensation torque calculation unit that, on the basis of the reference gravity torque and the current attitude, calculates a gravity compensation torque for compensating a torque component generated about the turning axis by the gravity in the current attitude; and a correction unit that corrects the torque command value by using the gravity compensation torque so as to cancel the torque component generated about the turning axis by the gravity in the current attitude.

A control device generates an operation signal for controlling a pressure of hydraulic oil on a downstream side of the swing motor in a hydraulic device based on an azimuth direction, a swing speed, and a target stopping azimuth direction of a swing body during braking of a swing motor.

An excavator includes a lower traveling body; an upper turning body turnably mounted to the lower traveling body; an actuator configured to change an orientation of the upper turning body; and a control apparatus configured to perform front-face control to operate the actuator such that the upper turning body is caused to front-face a target surface, based on information regarding the target surface and information regarding the orientation of the upper turning body, wherein the control apparatus performs the front-face control such that the upper turning body maintains a state of front-facing the target surface.

To provide a work machine that can stop unexpected operation of actuators faster than it actually occurs even if unintended operation occurs at the time of gate lock lever switching that leads to such unexpected operation. In the work machine, a controller switches a lock valve from a lock position to a release position in a case where a lock operation device is operated from a permission position to a prohibition position; decides, on the basis of a result of detection by a pressure sensor, whether or not a pilot hydraulic fluid has been output from a pilot valve until first time elapses after the lock valve is switched to the release position; keeps the lock valve at the lock position if it is decided that the pilot hydraulic fluid has been output until the first time elapses; and switches the lock valve from the lock position to the release position if it is decided that the pilot hydraulic fluid has not been output until the first time elapses, and second time elapses.