Freight elevator is a vertical transportation equipment mainly used for transporting goods and personnel. The design concept mainly includes the following aspects:

1. Safety: Freight elevators must ensure the safety of passengers and cargo. When designing, various safety measures need to be considered, such as emergency stop switches, overload protection, speed limiters, etc.

2. Efficiency: Freight elevators need to be able to transport goods and personnel quickly and efficiently. When designing, factors such as elevator speed, load capacity, and operating frequency need to be considered.

3. Comfort: Freight elevators need to provide a comfortable riding environment. When designing, factors such as elevator noise, vibration, and air circulation need to be considered.

4. Stability: Freight elevators need to maintain stable operation. When designing, factors such as the structure, materials, and manufacturing process of the elevator need to be considered.

5. Maintainability: Freight elevators need to be easy to maintain and upkeep. When designing, factors such as the structure, components, and maintenance methods of the elevator need to be considered.

6. Environmental friendliness: Freight elevators need to minimize their impact on the environment as much as possible. When designing, factors such as energy consumption, emissions, and noise of elevators need to be considered.

In general, the design concept of freight elevators needs to comprehensively consider multiple factors such as safety, efficiency, comfort, stability, maintainability, and environmental friendliness to meet the needs of passengers and goods, while minimizing the impact on the environment.