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What is a Hydraulic Engine?

Jessica Reed
Jessica Reed

A hydraulic engine is any engine powered by pressurized fluid, commonly referred to as hydraulic fluid. Hydraulic technology provides a more environmentally friendly way to power everything from automobiles to heavy machinery through the use of liquid. The hydraulic engine is a similar idea to the popular electric-powered car concept, with the exception that a hydraulic engine would use fluid instead of electricity to power it.

Today's technology has not yet created a functioning hydraulic car engine, and modern internal combustion engines still run on gasoline or diesel. The liquid is pumped in and an explosion ignites it to create power. A cleaner and more renewable resource comes from hydraulics. This type of engine would use pressurized fluid to move cylinders and other parts of the car. Hydraulics can create a powerful force through a small tube, thus making it a key choice for creating efficient engines that produce vast quantities of power while taking up little space and without requiring complicated systems or parts for it to work.

Man with hands on his hips
Man with hands on his hips

Current technology uses several hydraulic parts, such as hydraulic motors and cylinders, to power part of the machine they're located in. Hydraulic hybrid cars are finding ways to use hydraulics to work together with the car's engine and power different parts of the car. As technology advances, more parts can run off hydraulic fluid. While the engine itself currently still runs off gasoline or diesel, a combination of hydraulic parts help it out by doing some of the work and giving the engine a break.

Key components of any hydraulic technology include a hydraulic pump — which is powered by the engine — hydraulic cylinders, and hydraulic motors. The hydraulic pump is used to pump hydraulic fluid into the areas that need it. Hydraulic motors fill with fluid and the force causes them to turn, thus powering part of the machine.

Hydraulic cylinders play a special role in hydraulic technologies and may one day lead to the creation of a hydraulic engine for cars instead of a combination between hydraulic and combustion powered parts. The hydraulic cylinder fills with pressurized fluid, which forces the piston inside to move up. When the piston moves, it causes some other part of the machine to move as well.

In today's internal combustion engines, a small explosion causes the piston to move. In the hydraulic cylinder, fluid causes this movement instead and a valve opens to let the fluid out while new fluid comes in to start the process over again. It doesn't require the explosion of a internal combustion engine, and doesn't release pollutants into the environment the way gasoline and diesel emissions do.

Discussion Comments


Please explain what provides the pressurised fluid.


Has there been any attempts to produce a hydraulic engine? Obviously it would need the assistance of an electronic motor, but my whole idea is to revamp the internal engine in my car to a hydraulic engine. Keeping the crank, connecting rods and the pistons all the same. Have two variable pumps in sync, one in, one out.

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