Disclosed embodiments include power machines with a lower implement pivotally coupled to an undercarriage frame by a lower lift arm structure and which include one or more cylinders or actuators that are operable to pivot the lower lift arm structure and lower implement relative to the undercarriage frame. A configuration of the one or more cylinders which mounts the cylinders behind the lower implement, with attachments to the undercarriage and to the lower lift arm structure at positions which allow the cylinders to be surrounded and protected by the undercarriage, reduces damage to the cylinders during operation.

A shovel includes a lower traveling body, an upper swiveling body that is rotatably mounted on the lower traveling body, and a controller configured to perform straight facing control by which an actuator is operated to cause the upper swiveling body to face a target construction surface straight, based on information related to the target construction surface and information related to a direction of the upper swiveling body.

A speed reducer includes a transmission unit rotating around an axis, an annular member having a cylindrical shape surrounding the axis, rotating around the axis together with the transmission unit, and having an oil sump having a recessed groove recessed in an inner peripheral surface and a lubricating oil supply hole extending and opening radially outward from the recessed groove, and a sliding portion provided radially outward of the lubricating oil supply hole of the annular member.

A hybrid construction machine includes: a motor generator system connected to an internal combustion engine and performing a motor generator operation; an electric power accumulation system connected to the motor generator system; a load drive system connected to the electric power accumulation system and being driven electrically; an abnormality detection part equipped to the motor generator system, the electric power accumulation system and the load drive system; and a main control part determining whether an abnormality has occurred based on a detection value of the abnormality detection part. When the abnormality determination part determines that an abnormality has occurred, the main control part stops a drive of a drive system in which the abnormality is detected in the load drive system.

The present invention relates to a hydraulic unit with a housing in which a hydraulic converter is accommodated, which is coupled with a drive shaft that includes a connecting shaft piece located outside the housing for connection to a mechanical drive element The invention furthermore relates to a hydraulic driving device with such hydraulic unit and to a drive train connecting piece to which the hydraulic unit is connected. It is proposed to integrate a clutch for connecting and disconnecting the hydraulic unit into the hydraulic unit itself, so that a mechanical drive train, to which the hydraulic unit is connected, can remain unchanged or need not especially be adapted to the clutch. In accordance with the invention, a clutch for coupling and uncoupling the connecting shaft piece of the hydraulic unit to and from the hydraulic converter of the hydraulic unit is accommodated in the housing of the hydraulic unit.

A working machine includes a lower body, a turning body, a turning manipulating member which turns the turning body, a hydraulic motor which rotationally drives the turning body, a brake device which brakes the hydraulic motor, a main hydraulic source which supplies hydraulic oil to the hydraulic motor, and a direction control valve which controls a flow direction of the hydraulic oil according to the manipulated variable of the turning manipulating member, in which in a state where the hydraulic motor is braked by the brake device based on a manipulation of a brake manipulating member, when the turning manipulation is performed by the turning manipulating member, a brake applied to the hydraulic motor by the brake device is released with respect to turning in an indication direction indicated by the turning manipulation such that the turning body turns in the indication direction.

An engine cover (23) is provided between a counterweight (7) and a rear surface part (15B) of a cab (15) to be capable of opening/closing in an upper-lower direction and a heat exchanger cover (28) is provided between the rear side of a left side surface part (15C) and a right side surface part (15D) of the cab (15) and a revolving frame (6). The heat exchanger cover (28) is formed of a horizontal-opening structure of being rotatable in a front-rear direction to the revolving frame (6) with a front end (28C) in the front-rear direction as a fulcrum and a rear end (28D) in the front-rear direction as a free end. A heat exchanger cover lock mechanism (32) is provided on the rear end side of the heat exchanger cover (28) to hold the heat exchanger cover (28) in a closed state, and in a state where both the heat exchanger cover (28) and the engine cover (23) are closed, the engine cover (23) covers the rear end (28D) of the heat exchanger cover (28) and the heat exchanger cover lock mechanism (32) from backward.

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.

It is determined whether a velocity estimation model is established from an actual operating velocity Vr and a target operating velocity Vt of each of actuators 20A, 21A, and 22A; in a case in which the velocity estimation model is established, a dynamic center-of-gravity position of a hydraulic excavator 1 in a case in which each of the actuators 20A, 21A, and 22A is suddenly stopped from a driven state is predicted from an estimated operating velocity Ve; in a case in which the velocity estimation model is not established, the dynamic center-of-gravity position is predicted from the actual operating velocity Vr and it is determined whether to execute control intervention using the predicted dynamic center-of-gravity position; and in a case in which it is determined to execute the control intervention, the target operating velocity Vt is corrected in such a manner that each of the actuators 20A, 21A, and 22A slowly decelerate. It is thereby possible to appropriately carry out operating velocity limiting on a front work implement 2 and slow deceleration of the front work implement 2 and to suppress reductions in workability and operability, a deterioration in a ride quality, and the like even in a case of work involving an abrupt change in disturbance or a change in the lever operation amount within minute time.

Lifting performance of a work machine is increased while suppressing an increase in a vehicle weight. When a slewing frame is seen from a side, a first reinforcement member is provided from a boom foot section to a front side part of a slewing bearing, a second reinforcement member is provided from the boom foot section to a mast foot section, and a third reinforcement member is provided from the mast foot section to a rear side part of the slewing bearing. Furthermore, a fourth reinforcement member is provided from a middle region (M) located at an upper end portion of the slewing frame and above a rear portion of the slewing bearing to the front side part of the slewing bearing, and a fifth reinforcement member is provided from the middle region (M) to the rear side part of the slewing bearing.