Telescoping Boom Crane
The crane mainly includes a hoisting mechanism, an operating mechanism, a luffing mechanism, a slewing mechanism and a metal structure. The hoisting mechanism is the basic working mechanism of the crane. It is mostly composed of a hanging system and a winch, and also has a heavy lifting and lowering through a hydraulic system. The operating mechanism is used to vertically move heavy objects or adjust the working position of the crane, which is generally composed of an electric motor, a speed reducer, a brake and a wheel. The luffing mechanism is only equipped on the boom type crane. When the boom is raised, the amplitude is reduced, and the amplitude is increased when the arm is lowered, and the balance and the unbalanced amplitude are divided into two types. The slewing mechanism is used to rotate the boom and is composed of a driving device and a slewing bearing device. The metal structure is the skeleton of the crane. The main bearing members such as the bridge frame, the boom frame and the door frame can be a box-shaped structure or a truss structure, or a web structure, and some can be used as a support beam.
Main performance parameters of cranes:
The main parameters of the crane are the parameters that characterize the main technical performance of the crane. It is the basis for the crane design and an important basis for the crane safety technical requirements.
Crane weight G
Self-weight refers to the mass of the whole machine in standard configuration, in tons (t) or kilograms (kg).
Lifting weight Q
Lifting weight refers to the mass of the lifted object. Can be divided into rated lifting capacity, maximum lifting capacity, total lifting weight, effective lifting weight and so on.
Rated lifting weight Qn
The rated lifting capacity is the sum of the mass of the crane that can be lifted together with the mass of the spreader or attachment (such as grab, electromagnetic chuck, balance beam, etc.).
Total lifting weight Qz
The total lifting weight is the sum of the mass of the crane hoisting material together with the spreader and the spreader that is permanently attached to the crane (including hooks, pulley blocks, hoisting ropes and other hoisting objects below the hoisting trolley).
Effective lifting weight Qp
The effective lifting capacity is the net mass of the material that the crane can lift.
This parameter needs to be explained as follows:
First, the lifting weight on the crane sign is usually the rated lifting capacity of the crane and should be prominently indicated in the obvious position of the crane structure.
Second, for boom type cranes, the rated lifting capacity varies with the amplitude, and the lifting characteristics are characterized by the lifting torque. The value calibrated on the label is the maximum lifting capacity.
Third, cranes with separable spreaders (such as grabs, electromagnetic chucks, balance beams, etc.), their spreaders and material quality of the overall service rated lifting capacity, allowing the quality of the lifting materials to be effective lifting capacity.
Lifting height H
Lifting height refers to the vertical distance of the top surface (or ground) of the crane running track to the extreme position on the pick-up device, in m. When the hook is usually used, the center of the hook and hook ring is counted; when the grab and other containers are used, the bottom of the container is counted.
Depth of depth h
When the take-up device can be placed on the ground or below the top surface of the track, the drop distance is called the descent depth. That is, the vertical distance between the lowest working position of the spreader and the horizontal bearing surface of the crane.
Lifting range D
The lifting range is the sum of the lifting height and the falling depth, that is, the vertical distance between the highest and lowest working positions of the spreader.
Span refers to the horizontal distance between the centerline of the running track of a bridge type crane, in m.
The distance between the centerline of the trolley running track of the bridge type crane is called the gauge of the trolley.
The distance between the centerline of the running track of a boom-type crane running on the ground is called the gauge of the crane.
The amplitude of a rotating jib crane is the horizontal distance between the center of rotation and the plumb line of the pick-up device, in m. The amplitude of a non-rotating type of boom crane refers to the water, flat distance between the spreader centerline to the rear axle of the boom or other typical axis.
When the boom inclination is the smallest or the distance between the trolley position and the swing center of the crane is the largest, the amplitude is the maximum amplitude; otherwise, the minimum amplitude.
Working speed V
Working speed refers to the speed at which the crane working mechanism runs stably under the rated load.
Lifting speed Vq
The lifting speed refers to the vertical displacement speed of the rated load of the crane under stable operation, and the unit is m/min.
Car running speed Vk
The running speed of the cart refers to the running speed of the crane with the rated load on the horizontal road or track, in m/min.
Car running speed Vt
The running speed of the trolley refers to the running speed of the trolley with the rated load on the horizontal rail under stable motion, and the unit is m/min.
Variable speed V1
The variable amplitude is the horizontal displacement average linear velocity from the maximum amplitude to the minimum amplitude, in m/min, under the steady motion state.
Walking speed V.
The walking speed refers to the smooth running speed of the rated load of the mobile crane when the road is running, and the unit is km/h.
Rotation speed ω
The rotational speed refers to the rotational speed of the crane around its center of rotation under steady motion, in units of r/min.