Structure and working principle of elevator
The elevator is mainly composed of the car, the traction system, the guide rail and the control system. The car is used to hold passengers or articles, including the control panel. Passengers transmit the required level signals to the control system through the corresponding buttons of the control panel, or directly control the opening and closing.
The traction part includes the traction steel cable, the pulley group, the motor in the machine room and the steel cable stranded wheel, and the weight added to the other end of the traction steel cable. When the motor drives the steel cable twisting wheel, the elevator is pulled up and down by friction. For safety, the elevator is traced by a group of steel cables, and each steel cable can stand the weight of its traction alone. The transmission of traction power is generally divided into two types of retarder type and no retarder type. The former passes the rotation of the motor spindle to the cable winch by the turbine vortex rod reducer, the latter is directly installed on the main shaft of the electric motor by changing the steel cable winch, and the speed is controlled by changing the magnitude of the current passing through the motor. In order to make the car and counterweight do not have lateral movement during the vertical movement, the car guide and the counterweight guide are set up respectively.
Commonly used automatic elevator adopts centralized control mode. The control system is composed of car inner control panel, waiting door control panel, hierarchical control memory and lifting control cabinet. The function of the control board is to transmit the passenger instruction signal. The hierarchical control memory stores the instructions of the passengers in the car and the waiting doors, and arrange the calling hierarchy program according to the rules of high priority and so on, issuing the ascending, descending and stopping instructions. The lift control cabinet controls the acceleration, deceleration, positive rotation, reversal and shutdown of the motor according to the rise, drop and stop instructions.
Many elevators in large high-rise buildings are usually operated by automatic group control. A group control system is composed of 3~8 elevators. According to the number of passengers in the cabin, the instructions inside and outside the car, the location of the elevator and the location of the car, the elevator operation is automatically dispatched.