Currently, the stacker crane consists of the following parts:
1. Lifting mechanism: The lifting mechanism of a stacker crane can be composed of an electric motor, brake, reducer or sprocket, and flexible components. Commonly used flexible components include steel wire ropes and lifting chains. Steel wire ropes are used as flexible components with light weight and low noise; Using chains as flexible mechanisms is relatively compact. In addition to ordinary gear reducers, the use of worm gear reducers and planetary gear reducers is often seen due to the need for a larger reduction ratio. The lifting speed should be equipped with low gears and low speeds, mainly used for smooth and accurate stopping, as well as for extremely short distance lifting and lowering of forks and cargo platforms when picking up and unloading goods. The working speed of the lifting mechanism is generally between 12-30m/min. In the three driving modes of the stacker crane, namely lifting, walking, and forking (picking up goods), the lifting power is high.
2. Operating mechanism: The commonly used operating mechanisms are the ground support type for ground walking and the suspension type or shelf support type for upper walking. The ground walking type uses 2-4 wheels to run on single or double tracks on the ground, and the top of the column is equipped with guide wheels. The upper walking type adopts 4 or 8 wheels suspended on the lower flange of the I-beam at the bottom chord of the roof truss, and there are horizontal guide wheels at the bottom. The upper part of the shelf support type has 4 wheels that walk along the two guide rails at the top of the shelves on both sides of the roadway, and there are also horizontal guide wheels at the lower part.
3. Loading dock and storage and retrieval mechanism: The loading dock is the load-bearing device of the cargo unit. For a picking stacker that only needs to pick a portion of the goods from the cargo bin, there is no storage and retrieval device on the cargo platform, and only the platform is used for placing cargo containers. The storage and retrieval device is a special working mechanism of the stacker crane. The structure of the pick-up section is designed based on the external characteristics of the goods. A common type is a telescopic fork, which can also be a retractable pickup board or other structural form.
The extension fork mechanism is installed on the cargo platform, which moves vertically along the guide rail on the column under the support of the rollers (lifting). The direction perpendicular to the lifting - walking plane is the direction of the extension fork. The operating platform of the stacker crane is located on the base, where workers can perform manual or semi-automatic operations. After the fork is extended, its length is about twice the original length. The general cargo fork adopts a three section mechanism, with the lower fork fixed on the cargo platform, and the middle and lower forks can extend left and right. When the driving gear 1 rotates clockwise, the middle fork moves to the left; Under the traction of the chain, the upper fork also moves to the left to achieve the purpose of extending the fork to the left. When the driving gear 1 rotates counterclockwise, it extends to the right.
4. Rack: The rack of the stacker consists of a frame consisting of columns, upper crossbeams, and lower crossbeams. According to the different frame structures, the stacker can be divided into two types: double column and single column stackers. The double column stacker is a rectangular frame composed of two columns and upper and lower crossbeams. There are two structural forms of columns: square tube and circular tube. The square tube can be used as a guide rail, and the circular tube needs to be attached with a lifting guide rail. Its characteristics are high strength and stiffness, stable operation, and high operating speed. Mainly used in three-dimensional warehouses with high lifting height and large lifting capacity. A single column stacker is composed of a column and a lower crossbeam, with additional guide rails attached to the column.
