A hydraulically actuated liftable and lowerable hook of a crane has a hydraulic system comprises at least one working machine with a hydraulic motor driving a winch. At least one drive machine comprising a pump is connected directly or indirectly to at least one of the working machines by means of two connections via corresponding working lines, which serve as a feed or return depending on the operating state of the working machine. A lowering brake valve is provided in one working line and is connected to the other working line via a control line such that the lowering brake valve is displaceable against a restoring force by pressure, which prevails in the other working line and is forwarded via the control line, from the blocking position of said valve into a through-flow position for lowering the hook by means of a primary winch.

A hydraulic system for powering a winch assembly of a work machine includes a hydraulic reservoir, a pump, a cooling system, a first path of travel, and a second path of travel. The first path of travel is disposed between the pump and the cooling system, and the winch assembly is powered by the hydraulic fluid moving along the first path of travel. The second path of travel is disposed between the pump and the cooling system. When the winch assembly is in an active condition, a first valve is in an open position such that the hydraulic fluid moves along the first path of travel and through the cooling system. When the winch assembly is in an idle condition, a second valve is in an open position such that the hydraulic fluid moves along the second path of travel and through the cooling system.

A hydraulic system for powering a winch assembly of a work machine includes a hydraulic reservoir, a pump, a cooling system, a first path of travel, and a second path of travel. The first path of travel is disposed between the pump and the cooling system, and the winch assembly is powered by the hydraulic fluid moving along the first path of travel. The second path of travel is disposed between the pump and the cooling system. When the winch assembly is in an active condition, a first valve is in an open position such that the hydraulic fluid moves along the first path of travel and through the cooling system. When the winch assembly is in an idle condition, a second valve is in an open position such that the hydraulic fluid moves along the second path of travel and through the cooling system.

The present invention discloses a multi-channel impact-resistant intelligent-constant-deceleration hydraulic braking system, and relates to the field of safety braking control for mine hoist systems. A technical point of the braking system is that the braking system includes a braking circuit formed by a constant-deceleration hydraulic system, a constant-deceleration electrical closed-loop control system, and a detection and feedback apparatus. The constant-deceleration hydraulic system is provided with N+1 independent complete oil return channels, where N is a positive integer greater than or equal to 3. The oil return channels are disposed in parallel to form parallel independent braking circuits, that is, are multi-channel and do not have a common output point. The oil return channel includes a backup oil source, an electro-hydraulic signal conversion and amplification component, an operating mode switching apparatus, and an execution component that are sequentially connected. The oil return channels include one backup channel and N working channels. Functions such as constant-deceleration braking, impact and vibration limiting, rope slip prevention, derailing prevention, and overwinding prevention can be safely and reliably achieved when a mine hoist system normally stops, performs operation braking or performs safety braking, thereby greatly reducing an accident rate.

The present invention relates to an apparatus for passively preventing a marine floating body from twisting during mooring by controlling tension in ropes connected to the marine floating body within a predetermined allowable limit. The apparatus includes: a floating main body connected to the ropes, fixed on the sea, and providing a space for marine work; winches disposed on the floating main body and retracting or releasing the ropes fixing the floating main body; fairleads disposed on portions of the floating main body and guiding the ropes to the winches through themselves; and braking units disposed on portions of the floating main body at a predetermined distance from the fairleads, with the ropes passing through the fairleads and themselves, and controlling a speed of the ropes that are retracted to the winches at a predetermined speed.

The present invention relates to a free-fall winch comprising a drum which can be rotatorily driven by a winch drive via a transmission and can be retained by a holding brake, wherein in addition to the holding brake a free-fall brake is provided for slowing down the drum in free-fall operation. According to the invention, the free-fall brake is arranged between winch drive and holding brake on the one hand and drum on the other hand such that when the free-fall brake is open, the drum is decoupled from the winch drive and from the holding brake and can be rotated at idle with respect to the winch drive and the holding brake.

A control device of a hydraulic winch includes an engine, a hydraulic pump, a hydraulic motor driving a winch drum, a winch manipulating member, an engine control unit controlling a rotation speed of the engine, a winch load detector detecting a load applied to the winch drum, and a motor capacity control unit controlling a motor capacity of the hydraulic motor so as to decrease a motor capacity of the hydraulic motor in a fuel-saving operation mode to a motor capacity which is smaller than a motor capacity of the hydraulic motor in a normal operation mode. The engine control unit sets an upper limit value of the rotation speed of the engine in the fuel-saving operation mode to a value which is lower than a maximum rotation speed of the engine in the normal operation mode and corresponds to the load detected by the winch load detector.

A control device of a hydraulic winch includes an engine, a hydraulic pump, a hydraulic motor driving a winch drum, a winch manipulating member, an engine control unit controlling a rotation speed of the engine, a winch load detector detecting a load applied to the winch drum, and a motor capacity control unit controlling a motor capacity of the hydraulic motor so as to decrease a motor capacity of the hydraulic motor in a fuel-saving operation mode to a motor capacity which is smaller than a motor capacity of the hydraulic motor in a normal operation mode. The engine control unit sets an upper limit value of the rotation speed of the engine in the fuel-saving operation mode to a value which is lower than a maximum rotation speed of the engine in the normal operation mode and corresponds to the load detected by the winch load detector.

The invention relates to a free fall winch comprising a drum, which can be rotationally driven by a winch drive, wherein a free fall brake is provided for braking the drum in free fall operation. According to the invention, a torque acting on the free fall winch, which depends on the free fall braking torque, is detected by means of a detection device, and a brake actuation force with which the free fall brake is actuated is controlled or adjusted by a control device according to the detected torque.

A system for controlling a winch assembly having a hydraulic motor, a drum, a cable, and a cable tension sensor. A controller is configured to access a winch load threshold defining a hold zone and a reel zone, and one of the hold zone and the reel zone including loads greater than the winch load threshold and another of the hold zone and the reel zone including loads less than the winch load threshold. The controller is further configured to determine whether the winch assembly is operating within the hold zone or the reel zone, and generate a zero flow command while the winch assembly is operating within the hold zone to prevent rotation of the hydraulic winch motor, and generate a pressure differential command while the rotatable winch drum is operating within the reel zone to permit rotation of the hydraulic winch motor.