Abstract: The present application relates to a crane hydraulic system and a controlling method of the system, wherein the crane hydraulic system includes a load sensing subsystem, and the subsystem includes a variable pump, a variable pump oil inlet line, a load feedback line, an oil return line and a pressure compensator; the pressure compensator is provided with an oil inlet, an oil outlet, a first control oil port, a second control oil port and a control spring; the oil inlet communicates with the variable pump oil inlet line, the oil outlet communicates with the oil return line, the first control oil port communicates with the load feedback line, and the second control oil port also communicates with the variable pump oil inlet line; and wherein the control spring and the first control oil port are located on the same end of the pressure compensator, and a set pressure of the control spring is greater than a pressure difference of the variable pump.

Abstract: A track hitching structure is for a wheeled crane and the wheeled crane, and includes a vehicle frame and a connecting cross beam. The first end of the connecting cross beam is connected with a track. The second end of the connecting cross beam is connected with the vehicle frame. The second end of the connecting cross beam is higher than the first end of the connecting cross beam. The vehicle frame is connected with the track by the connecting cross beam with one high end and one low end, so the long-distance force transfer from the track to the race of the vehicle frame can be handled, then the shortcomings of tedious structure, large size, large weight and the like of the connecting device caused by a horizontal connecting cross beam are avoided, and the reliability and the working performance of the entire crane are improved.

Abstract: The present invention relates to a single-cylinder plug pin type telescopic arm, a crane and a telescopic method thereof. The single-cylinder plug pin type telescopic arm includes a basic arm and at least one telescopic arm sleeved in the basic arm, wherein coaxial center holes are formed in the tails of the telescopic arms, and a telescopic oil cylinder is arranged in the center holes; the telescopic oil cylinder includes a cylinder rod and a cylinder barrel, at least two cylinder heads are fixedly sleeved on the outer side of the cylinder barrel in the longitudinal direction, and at least three arm pin holes are formed in each of the basic arm and the telescopic arms in the longitudinal direction.

Abstract: The present disclosure discloses an operating method of a wind power jib of a crane and a crane, and relates to the field of engineering machinery. The method includes the following steps: rotatably connecting a main boom and a wind power jib; overturning the wind power jib to a first preset position by using a traction means of the crane; contacting a cushioning member with the wind power jib provided at the first preset position; further drawing the wind power jib to overturn to a second preset position; releasing the traction means, such that the wind power jib overturns automatically under the effect of self gravity and a cushioning member until the wind power jib is overturned in position.

Abstract: The invention relates to a cylinder head body, a single cylinder bolt system and a crane, wherein, the cylinder head body comprises at least two branch bodies of cylinder head body, a cooperative positioning structure and a fixed connection structure are provided between two adjacent branch bodies of cylinder head body of the at least two branch bodies of cylinder head body, the branch body of cylinder head body has a cylindrical branch body structure, the cylindrical branch body structures of the at least two branch bodies of cylinder head body are cooperatively positioned by means of the cooperative positioning structure and are detachably connected by means of the fixed connection structure to form a barrel.

Abstract: The present application relates to a switching valve, a switching hydraulic system, and a crane, in which the switching valve having an oil inlet and an oil outlet comprises at least two pairs of valve oil ports, a pair of cartridge valves provided between each pair of valve oil ports, and the oil inlet and the oil outlet are controlled such that the oil inlet and the oil outlet are capable of shifting between communications with the at least two pairs of valve oil ports. The switching valve switches on and off communication between the oil inlet and the oil outlet and the at least two pairs of valve oil ports by controlling opening or closing of the cartridge valves.

Abstract: A wheeled crane and self-demounting and self-mounting methods for supporting legs thereof is disclosed. The wheeled crane includes a vehicle frame and auxiliary supports, and the auxiliary supports can enable the vehicle frame to keep balance. Since the wheeled crane has auxiliary supports, when the supporting legs are demounted or mounted, the auxiliary supports function as supporting legs, so that the supporting legs can be mounted and demounted by the operation part of the wheeled crane with no need of using an auxiliary crane, and thus the self-mounting and self-demounting of the supporting legs of the wheeled crane are realized.

Abstract: A steering arm assembly includes a steering arm body, a first rotary connecting part and a second rotary connecting part. A first end and a second end of the steering arm body are fixedly connected with a first rocker arm and a second rocker arm, respectively. The first rotary connecting part and the second rotary connecting part are respectively connected with the first end and the second end of the steering arm body, and the steering arm body is configured to rotate relative to the first rotary connecting part and the second rotary connecting part. The steering arm body is able to be detachably located on a mounting bracket through the first rotary connecting part and the second rotary connecting part; and the first rotary connecting part and the second rotary connecting part respectively include a first shaft housing and a second shaft housing, which are engaged with a first mounting plate and a second mounting plate respectively.

Abstract: 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.

Abstract: A track hitching structure is for a wheeled crane and the wheeled crane, and includes a vehicle frame and a connecting cross beam. The first end of the connecting cross beam is connected with a track. The second end of the connecting cross beam is connected with the vehicle frame. The second end of the connecting cross beam is higher than the first end of the connecting cross beam. The vehicle frame is connected with the track by the connecting cross beam with one high end and one low end, so the long-distance force transfer from the track to the race of the vehicle frame can be handled, then the shortcomings of tedious structure, large size, large weight and the like of the connecting device caused by a horizontal connecting cross beam are avoided, and the reliability and the working performance of the entire crane are improved.

Abstract: The present disclosure discloses a method and system for positioning an engineering machinery work object.

Abstract: A method and a system for recovering and utilizing crane operating energy and a crane includes converting by a first hydraulic power means hydraulic energy generated by a hydraulic actuator into mechanical energy of a transmission shaft; driving, by the transmission shaft, a second hydraulic power means to rotate so as to convert the mechanical energy of the transmission shaft into mechanical energy of the second hydraulic power means; filling, by the second hydraulic power means, pressurized oil into an accumulator so as to convert the mechanical energy of the second hydraulic power means into hydraulic energy for storage.

Abstract: The present invention relates to a single-cylinder plug pin type telescopic arm, a crane and a telescopic method thereof. The single-cylinder plug pin type telescopic arm includes a basic arm and at least one telescopic arm sleeved in the basic arm, wherein coaxial center holes are formed in the tails of the telescopic arms, and a telescopic oil cylinder is arranged in the center holes; the telescopic oil cylinder includes a cylinder rod and a cylinder barrel, at least two cylinder heads are fixedly sleeved on the outer side of the cylinder barrel in the longitudinal direction, and at least three arm pin holes are formed in each of the basic arm and the telescopic arms in the longitudinal direction.