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Understanding the Working of Hydraulic Elevators
04 June, 2010-
The basic concept of an elevator is quite simple. In the most fundamental terms, it is nothing but a compartment attached to a lifting system. Though the concept is simple but a lot of technical detailing goes into making the elevators work. Generally, there are two types of elevators, namely hydraulic elevators and roped elevators.
Here lets discuss the working of hydraulic elevators in detail. Hydraulic elevators lift the car using a hydraulic ram i.e. a fluid driven piston which is set inside a cylinder as depicted in the figure below:
This cylinder is connected to a fluid-pumping system which is a combination of three components, namely:
»A tank which is actually a fluid reservoir
»A pump which sources its power through an electric motor
»A valve which is set between the cylinder and the reservoir
In such a setting, the pump pushes the fluid from the tank into the pipe which leads towards the cylinder. At the time when the valve is open, the pressurized fluid tends to take on the least resistant path and moves back to the reservoir. But in case the valve is closed, the pressurized fluid has no other option except going into the cylinder. Now, while the fluid gets collected within the cylinder, it makes the piston move upwards thus, lifting the elevator car.
As soon as the car reaches the desired floor, the control system signals the electric motor to eventually shut off the pump. Since the pump is set off, fluid too, stops flowing into the cylinder. Though the fluid which is already there stands still within that position only. This makes the piston rest on the fluid and the car too stands still at the position where is was stopped.
In order to bring down the elevator car, the control system again sends a signal to the valve. The valve here is electrically operated through a simple solenoid valve. As soon as the solenoid opens the valve the collected fluid moves from the cylinder to the reservoir, hence, making the elevator car descend down smoothly. At last to make the car stop at the bottom the system again closes the valve and the car again comes to standstill.
Here lets discuss the working of hydraulic elevators in detail. Hydraulic elevators lift the car using a hydraulic ram i.e. a fluid driven piston which is set inside a cylinder as depicted in the figure below:
Working of Hydraulic Elevator
This cylinder is connected to a fluid-pumping system which is a combination of three components, namely:
»A tank which is actually a fluid reservoir
»A pump which sources its power through an electric motor
»A valve which is set between the cylinder and the reservoir
In such a setting, the pump pushes the fluid from the tank into the pipe which leads towards the cylinder. At the time when the valve is open, the pressurized fluid tends to take on the least resistant path and moves back to the reservoir. But in case the valve is closed, the pressurized fluid has no other option except going into the cylinder. Now, while the fluid gets collected within the cylinder, it makes the piston move upwards thus, lifting the elevator car.
In order to bring down the elevator car, the control system again sends a signal to the valve. The valve here is electrically operated through a simple solenoid valve. As soon as the solenoid opens the valve the collected fluid moves from the cylinder to the reservoir, hence, making the elevator car descend down smoothly. At last to make the car stop at the bottom the system again closes the valve and the car again comes to standstill.
