Stacker Crane––the Secret of the Core of the Warehouse

The stacker crane is the core equipment of the entire automated warehouse. It is a very important lifting and transportation equipment in the intelligent warehouse. Store the goods at the entrance of the aisle in the storage location unit or take out the storage location unit and transport it to the entrance of the aisle to complete the inbound and outbound operations. It consists of a frame(upper beam, lower beam, column), horizontal traveling mechanism, lifting mechanism, cargo platform, fork, and electrical control system(the previous article has a specific introduction.

Stacker crane types:

1. Divided by speed: conventional stacker, high-speed stacker

2. According to the mechanical structure: single column, double column

3. According to the direction of the crane rail track: straight track type, curved track type, transition track type, and fork track type.

Single-column rail roadway stacker:

1. Low cost: the column of the single-column stacker is generally made of large H-shaped steel or welding, and there are guide rails attached to the column. Its overall weight is lighter and the consumables are less, so the cost will be relatively low.
2. Lifting structure: The lifting structure of the single-column stacker is generally driven by a steel wire rope, and then the motor reducer drives the reel to rotate, and then the steel wire rope pulls the loading platform along the column or lifting rail for lifting operation.
3. Driving device: the horizontal driving device of the single-column stacker is generally hidden on the power bean of the stacker, and then the motor is used to drive the rotation of the wheel through the reducer so that the stacker moves along the horizontal direction. (Note: generally, two load-bearing wheels are used, and then run along the track(usually called ground track) laid on the ground).
4. Auxiliary guidance: it is guided along the track through the lower two sets of horizontal wheels, and then the two sets of guide wheels on the top of the stacker run along the upper track(usually called the sky rail) for auxiliary guidance.

Disadvantages of the single column:

1. Poor rigidity.
2. Limitation of use: this is because the loading platform and goods have an eccentric effect on the column, as well as the horizontal inertial force generated during walking and braking, which has caused limitations in the use of single-column stackers.
3. Scope of use: it is not suitable for stackers with heavy weight and high horizontal running speed.
4. Positional deviation: the wire rope transmission, transmission, and arrangement of the single-column stacker are relatively easy, but the positioning is deviation.

Double-column rail roadway stacker:

1. There are two types of columns, square tube, and round tube. The square tube is responsible for the lifting guide rail, and the round tube is attached to the lifting guide rail.
2. The double-column stacker has good rigidity and strength and runs smoothly.
3. Double-column stackers are generally used in warehouses with high heights, large lifting capacities, and high horizontal running speeds.
4. The lifting mechanism of the double-column stacker: chain transmission is generally used, and the motor reducer drives the sprocket to rotate so that the chain pulls the cargo platform to move up and down along the column or the guide rail of the lift.

Accurate positioning of the double-column stacker: the chain pulls the loading platform or the counterweight device. Due to the limitation of the space size, the transmission and arrangement are more complicated, but they can be accurately positioned.

Straight-line operation type stacker

it refers to the operation that can only be carried out on the straight-line track in the roadway, and the track operation cannot be switched by itself.

1. The roadway can only be converted by other conveying equipment.
2. It can realize the warehouse operation with a high frequency of entering and leaving the warehouse.
3. Can realize high-speed operation.
4. Wide range of applications

Curved stacker

Also known as the transition stacker, is connected to the lower beam through a vertical axis, and then can be operated on a circular or other curved track, that is, it can walk on a curve.

1. It can be transferred from one roadway to another roadway without other conveying equipment.
2. It is limited in use.
3. Scope of use: only suitable for warehouses with low frequency of entry and exit.
4. Frequency of entire and exiting the warehouse: because the site is limited by the turning radius, the speed will become very slow when turning, so it cannot meet the requirements of warehouse operations with a high evaluation rate of entering and leaving the warehouse.

General technical parameters of stacker stereoscopic warehouse

1. Ground rail: steel rail, aluminum rail
2. Equipment height: Max=42m
3. Fork form: single-deep telescopic forks, double-deep telescopic forks
4. walking:speed(4-300m/min frequency conversion control),

walking acceleration(≤2.5m/s²)

5. Lifting: speed(4-60m/min frequency conversion control),

lifting acceleration (≤1m/s²)

6. Fork: speed(4-60m/min frequency conversion control), lifting acceleration (≤1m/s²)

Stacker is important transportation equipment in the intelligent warehouse. The selection of its various technical parameters will directly affect the operation efficiency and economic benefits of the entire intelligent warehouse. Reasonable selection of various parameters will greatly improve the overall system. Efficiency and economic benefits, so the level of the stacker’s horizontal running speed, lifting speed, and fork telescopic speed, these three parameters are directly related to the efficiency of the entire intelligent warehouse.

Working principle

The stacker is driven by the traveling motor through the drive shaft to drive the wheels to move horizontally on the lower guide rail, the lifting motor drives the cargo platform vertical lifting movement, and the cargo fork on the cargo platform performs the telescopic movement. Through the three-dimensional movement of the navigation tree, the goods in the designated storage space can be taken out or the goods can be sent into the designated storage space. The walking addresser is used to measure the horizontal walking position of the stacker; the lifting addresser is used to control the lifting position of the loading platform; the direction of the fork is positioned by the proximity switch. Through photoelectric identification and conversion of optical communication signals, computer control is realized, and manual and semi-automatic control of the stacker control cabinet can also be realized. At the same time, the optimized speed regulation method is adopted to reduce the impact of the stacker when it is decelerating and stopping, greatly shortening the stacker, and improving the operating efficiency of the stacker.