Elevator Related Knowledge

1: Elevator classification

There are several classification methods for elevators. Different classification methods will cross each other. According to the purpose, elevators can be classified into the following categories:

 Passenger Elevators: Elevators designed to transport passengers have a wide range of applications.

Cargo lifts : It is possible to have people on board. Elevators designed primarily for the transport of goods are used in factory premises and warehouses.

Passenger and freight elevators: elevators that mainly carry passengers but can also transport goods.

Bed lifts: Elevators designed to transport beds (including patients) and medical equipment are used in hospitals and medical centers.

Residential elevators: elevators designed for transport of passengers and furniture, sofas, stretchers, etc., for residential buildings.

Miscellaneous elevators: The car space is restricted and no one is allowed to enter. It is mainly used to transport small quantities of food, books and documents.

Automotive elevators: Elevators designed for transporting vehicles, used in three-dimensional parking equipment.

Special elevators: Used in elevators with special requirements, including explosion-proof elevators, anti-corrosion elevators, and marine elevators.

Sightseeing elevators: At least one side of the hoistway and the car wall is transparent, and passengers can watch elevators outside the car, mainly to transport passengers.

 2 : Basic principles

The elevator is mainly divided into mechanical and electrical aspects.

Mechanical: Driven by a traction machine, the car moves upward and downward through the frictional force generated between the wire rope and the traction sheave; the counterbalancing weight is opposite to the running direction of the car.

Electrical: Controlled by the microcomputer program in the control cabinet and combined with the mechanical system to control the operation and stop of the elevator.

 3: Safety protection device for elevator

Overspeed protection device

When the elevator up and down operating speed exceeds the specified speed, the speed limiter safety switch will operate to stop the elevator.

Door locking electrical protection device

There are electrical interlocking switches on the hall door and the car door to verify that the door is fully closed. As long as there is a door that is not closed, the elevator will not operate.

Parking protection device (brake)

When the car arrives at the stop, the traction machine brake can ensure that the position of the car leveling floor does not change.

End station forced deceleration device

The upper and lower station forced deceleration switches are installed at the running speed change point to ensure that the elevator can reliably reduce the running speed when approaching the end station.

Terminal limit device

When the forced deceleration switch does not work, the limit switch will act, and the elevator will be forced to stop running and cannot go beyond this position, but it can change the direction of operation.

End station limit position protection device

Before the elevator reaches the end of the guide rail, the limit switch acts to cut off the elevator power supply and the elevator is forcibly stopped.

Dundi, top protection device

If the elevator fails due to the control system, the buffer inside the pit will protect the passenger from injury when the upper and lower operation exceeds the limit position.

Overload protection device

The weight of the car can be weighed. When the rated load is exceeded, the elevator will not start and a buzzer beep will sound. After the warning, the entering passengers will exit the car in time.

Fall protection device

The up and down running speed of the car is monitored by the speed limiter in real time. Once the car gets out of control and over speed, the speed limiter will start the safety gear and immediately stop the car on the guide rail.

Door protection device

Hall door locks and hall and car door safety switches can ensure that the door can't operate normally if there is no safe closing in place or if it is not locked. The national standards stipulate the magnitude of the closing force of the elevator and will not pinch passengers.

The car door panel is usually equipped with a safety touch panel to ensure that the door automatically reopens when the door panel is in contact with people and objects during the door closing process; in addition, non-contact door protection devices—infrared light curtain protection devices and ultrasonic waves are also provided. The monitoring device can reopen the door without touching the door and people.

Door protection device characteristics

During a 50-millisecond trip where the door automatically closes, the door protection function may disappear and the door protection device cannot be used to reopen the door. In order to improve the use efficiency of the elevator and the need to prevent chaos, after the door protection device continuously operates for a period of time, the elevator will forcefully close the door. If it is still closed, the elevator will send a fault signal and stop running.