A crane, in particular a loading crane, includes an arm system that has a plurality of arms. The crane also has a crane controller that is configured, in a coordinate control operating mode, to control the coordinates of the arm system. The crane controller has a user interface, and the user interface has at least one function which can be selected by a user and by way of which at least one of the degrees of freedom of the arm system can be restricted or is restricted in the coordinate control operating mode.

A power transmission control method and device for a crane and the crane includes setting the maximum working displacement of a secondary element corresponding to each gear of the crane; determining the current gear state and specific gear of the crane; determining the working mode of the secondary element from the gear state, and setting the maximum allowable displacement of the secondary element as the maximum working displacement corresponding to the specific gear. In the power transmission control method and device for the crane and the crane of the present invention, the maximum displacement of the secondary element is controlled for various gears, which can reduce power impact. A buffer mode is added to avoid influence on a vehicle due to loss of instant power generated at the moment of energy release completion and avoid vehicle jitter due to instable power resulting from the vehicle at low speed or a system suddenly disconnected.

A work vehicle includes: an operation tool that is operated by an operator; and a controller that determines a target flow rate for hydraulic oil fed to a hydraulic device on a basis of the amount of operation of the operation tool. The controller calculates a bleed-off target flow rate on a basis of the flow rate of hydraulic oil fed from a hydraulic oil pump and the target flow rate for hydraulic oil fed to the hydraulic device, calculates a bleed-off throttle differential pressure on a basis of a pressure of hydraulic oil fed from the hydraulic oil pump and a pressure of hydraulic oil in a hydraulic oil tank, calculates a bleed-off target opening area on a basis of the bleed-off target flow rate and the bleed-off throttle differential pressure, and controls a hydraulic oil control valve such that the bleed-off target opening area is achieved.

A lift device includes a chassis, a boom pivotally coupled to the chassis, a first leveling assembly pivotally coupled to a first end of the chassis, a second leveling assembly pivotally coupled to an opposing second end of the chassis, and a control system. The first leveling assembly includes a first pair of actuators positioned to facilitate a first pitch adjustment and a first roll adjustment of the first end of the chassis. The second leveling assembly includes a second pair of actuators positioned to facilitate a second pitch adjustment and a second roll adjustment of the opposing second end of the chassis. The control system is configured to (i) actively control the first pair of actuators and the second pair of actuators during a first mode of operation, and (ii) actively control the first pair of actuators and facilitate passive control of the second pair of actuators during a second mode of operation.

A boom assembly includes a lower boom, an upper boom, and an actuator assembly. The lower boom has an upper end and a base end. The base end is configured to be pivotally coupled to a lift device. The upper boom has a lower end pivotally coupled to the upper end of the lower boom. The actuator assembly has (i) a first end coupled to at least one of the upper end of the lower boom and the lower end of the upper boom, and (ii) an opposing second end coupled to the upper boom. The actuator assembly includes a first actuator and a second actuator. The second actuator is rigidly joined to the first actuator at the first end of the actuator assembly and flexibly joined to the first actuator at the opposing second end of the actuator assembly.

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.

An arrangement in a boom system, specifically in a forest machine, includes at least two interlinked boom parts and at least one power transmission connected to the boom parts for moving the boom parts in relation to each other and the environment. The boom part includes an elongated body with a hollow structure and at least one set of joints intersected by turning axles for attaching the boom part to an adjacent structure, and at least one set of attachments for attaching an actuator controlling the boom system to the body, whereby at least one boom part is formed as a uniform, hollow piece made of fluid material. The cross-section of the body is made to cinch toward the midpoint of the body.

An energy supply system includes a cable store for winding and unwinding an energy cable about a winding center of the cable store. A carrier is provided for the at least one energy cable, and the cable store has an opening for the inlet and outlet of the carrier and the energy cable. The carrier can be guided through the opening in order to guide the carrier and the energy cable in sections in the cable store to the winding center of the cable store over a first guide path through a first guide arc, over a second guide path, which adjoins the first guide arc, through a second guide arc, and over a third guide path, which adjoins the second guide arc and lies further inwards relative to the winding center than the first guide path, and optionally over additional guide paths and guide arcs, using guiding means.

A container trailer crane has an apparatus that includes a base, a crane arm, an outrigger, and a mechanical ram that is used in both positioning the outrigger and the crane arm.

An inventive boom arm for a concrete-distributing boom. The boom arm has an elongate box-profile support formed from two flanges and two webs connecting the flanges laterally. The boom arm has first and second articulation points spaced apart in the longitudinal direction of the boom arm. A first flange opening is disposed at the first articulation point and a second flange opening is disposed at the second articulation point. A sealing-partition seals a cavity region of the box-profile support at least in a region of the first and second flange openings. The sealing partition can be provided in the form of a plate that continuously spans the cavity region between the first and second articulation points and is connected laterally to the webs. The first articulation point is located at the end of the boom arm and is arranged within the cavity region and is covered by the partition plate.