Types and working principle of home elevators
In addition to the difference in price and materials, the biggest difference between elevators is the drive part. Different power sources determine different working principles, as well as different speeds and usage occasions. The common functions and equipment of these elevators such as door mechanism, lighting and emergency rescue are not discussed here. The following is a brief introduction to the working principles and related configurations of different types of home elevators.
1, Traction elevator
- The car of the traction elevator is pulled by a plurality of side-by-side steel cables or steel belts to travel between different floors.
- The traction power is generated by a three-phase motor. The steel cable and the steel belt are connecting the motor and the car.
- The two ends of the steel cable are mostly fixed on the load-bearing steel frame at the top of the guiding track.
- A group of sheaves are installed in the hoistway, on the car or counterweight. Steel cables are driven by a main sheave wheel, which is coaxial with the motor, so that the car is lifted and lowered together.
- The car runs on a track that is strictly perpendicular to the ground in the hoistway.
- For this type of traction elevator, the weight of the car mainly relies on the counterweight to balance it.
- Counter weight and the car share the same set of steel cables or belts. Counter weight runs up and down in the hoistway, which is opposite to the running direction of the car, and has its own special track.
- Taking into account the weight difference between the empty and full load of the elevator, the counterweight is generally twice the weight of the empty car.
- Whether running or stationary, the system relies on the static friction between the steel cable and the wire groove on the sheave wheels to provide acceleration, deceleration and balance.
- The case of no counterweight is only used for home elevators with relatively small loads.
- The motor regulates the speed through the reduction box or the frequency converter, and drives the hoist drum to roll up or down the cable, which is connected to the car, so as to realize the rise and fall of the car.
- Because of the size restriction of the hoist drum, the elevation height is also restricted.
- The speed regulation of current traction elevators mostly relies on the inverter designated to the elevator.
- First, the inverter rectifies the 3 phase AC power into DC power.
- Then, as per the running demand, DC power is inverted back into AC power again but of variable frequencies.
- The main synchronous motor is driven by the variable frequency AC to complete acceleration and deceleration.
2, Hydraulic elevator
- In addition to the car and track, other specific components of hydraulic elevators include oil tank, motor, oil pump, speed control solenoid valve, piston, pressure cylinder and pressure pipeline.
- To drive the car to rise, the motor drives the oil pump, which is immersed in the oil tank, to pressurize the hydraulic oil.
- Via the speed regulating solenoid valve and the pipeline, high press oil is sent to the cylinder so that the piston lifts the car under the pressure of hydraulic oil.
- To lower the car, the motor does not need to run. By opening the oil return solenoid valve, the hydraulic oil in the cylinder will return to the oil tank under the car weight so that the car is put down.
3, Screw elevator
- In addition to the general parts used for all elevators, the main components of the screw elevator include the motor, the reduction gear, the threaded bar and the meshing mechanism.
- The threaded bar or screw is installed in the hoistway along the vertical direction to the ground. The motor, belt or gearbox and meshing mechanism are installed on the car.
- After receiving the running command, the motor drives the meshing mechanism through belt or gearbox
- Because the motor and the mechanism are attached to the car, through the motor spinning and the engagement with the threaded bar, the car can climb and descend in the hoistway.
The above simply introduces the working principles of several types of elevators. As for the advantages and disadvantages of these elevators, how to choose a more suitable elevator for you, please check other related articles on this website for more details.