Light crane working principle and type
The light crane adopts a unique design concept with small size, light weight and small wheel pressure. Compared with the traditional crane, the limit distance from the hook to the wall is the smallest, and the clearance height is the lowest. The Keli crane is closer to the front work, and the lifting height is higher, which actually increases the effective working space of the existing plant. Due to the light weight and low wheel pressure of the light crane, the new plant can be designed to be smaller and more complete.
Light crane working principle：
It can be divided into two categories: one is centralized driving, that is, one motor drives the long drive shaft to drive the active wheels on both sides; the other is driven separately, that is, the active wheels on both sides are driven by one motor. Medium and small bridge cranes use the “three-in-one” drive method in which the brakes, reducer and electric motor are combined. The common bridge crane with large lifting weight is easy to install and adjust, and the drive unit often adopts universal joint.
Light crane structure type：
The crane operating mechanism generally uses only four active and driven wheels. If the lifting weight is large, it is common to increase the wheel to reduce the wheel pressure. When the number of wheels exceeds four, the articulated equalization frame device must be used to evenly distribute the load of the crane on each wheel.
The box-shaped structure can be further divided into two types: a normal-rail box-shaped double beam, a deviated rail-shaped double-beam, and a deviated box-shaped single main beam. The normal-rail box-shaped double beam is a basic form widely used. The main beam is composed of upper and lower flange plates and vertical webs on both sides. The trolley rail is arranged on the center line of the upper flange plate, and its structure is simple. It is easy to manufacture and suitable for batch production, but its weight is large.port crane
The cross-section box-shaped double-beam and the off-track box-shaped single main beam are composed of upper and lower flange plates and unequal-thick main and auxiliary webs. The trolley rails are arranged above the main webs, and the short-boosting of the casings The plate can be omitted, wherein the single-segment box-shaped main girder is replaced by a wide-flange box-shaped main beam instead of two main beams, and the self-weight is small, but the manufacturing is complicated. The four-truss structure is composed of four flat trusses combined into a closed space structure. The upper horizontal truss surface is generally covered with a walking platform, which has light weight and high rigidity. However, compared with other structures, the outer dimensions are large, the manufacturing is complicated, and the fatigue is complicated. Low strength and less production.
The metal structure of the bridge consists of main beam and end beam, which are divided into two types: single main beam bridge and double girder bridge. The single main girder bridge consists of a single main beam and end beams on both sides of the span. The double girder bridge consists of two main beams and end beams.
The main beam is rigidly connected to the end beam, and the ends of the end beam are provided with wheels for supporting the bridge to run on the elevated frame. The main beam is welded with a track for the lifting trolley to run. The main types of the main girder of the bridge are more typical of box-shaped structure, four-truss structure and hollow truss structure.