Hydraulic Elevator

A hydraulic elevator is a lift that moves up and down because oil is pushed under pressure into a strong metal tube. The main parts are an oil tank, a small motor that works like a heart, a long tube called a cylinder, a solid steel rod that fits inside the tube and a set of taps that open plus close to let the oil go where it needs to go. When the motor starts, it forces oil from the tank into the bottom of the cylinder. The trapped oil shoves the steel rod upward and the rod carries the lift car with it. When the lift needs to come down, a tap opens, the oil runs back to the tank and the car sinks at an even speed because its own weight pulls it. Hydraulic lifts do not use heavy balance blocks or wire ropes like the lifts in tall office towers. That keeps the parts list short but also the price low - builders pick them for buildings that rise no more than about seven floors. The ride feels calm and steady and the lift bears heavy loads without shuddering. You see those lifts in apartment blocks, small hospitals shopping plazas as well as private houses. Two versions exist. One version buries the long cylinder straight down into the ground beneath the shaft. The other version keeps everything above ground - short jacks stand on each side of the car and push it up from below. Both versions move smoothly, carry a lot of weight and go in quickly - they suit any place that needs only a moderate climb.