How a hydraulic lift works

Hydraulics are used in many aspects of our lives these days and have become essential tools in many industries. We believe that to get the best out of hydraulic equipment and machinery, it needs to be properly maintained and serviced regularly so that it is safe to use and works efficiently.

The concept of an elevator is incredibly simple — it’s just a compartment attached to a lifting system. Tie a piece of rope to a box, and you’ve got a basic elevator.

Of course, modern passenger and freight elevators are a lot more elaborate than this. They need advanced mechanical systems to handle the substantial weight of the elevator car and its cargo. Additionally, they need control mechanisms so passengers can operate the elevator, and they need safety devices to keep everything running smoothly.

There are two major elevator designs in common use today: hydraulic elevators and roped elevators.

Hydraulic elevator systems lift a car using a hydraulic ram, a fluid-driven piston mounted inside a cylinder. You can see how this system works in the diagram below.

The cylinder is connected to a fluid-pumping system (typically, hydraulic systems like this use oil, but other incompressible fluids would also work). The hydraulic system has three parts:

  • A tank (the fluid reservoir)
  • A pump, powered by an electric motor
  • A valve between the cylinder and the reservoir

The pump forces fluid from the tank into a pipe leading to the cylinder. When the valve is opened, the pressurized fluid will take the path of least resistance and return to the fluid reservoir. But when the valve is closed, the pressurized fluid has nowhere to go except into the cylinder. As the fluid collects in the cylinder, it pushes the piston up, lifting the elevator car. Click here to continue

Further information

How hydraulic car lifts work

Hydraulic tilt trailers