Automatic Transmissions & Basic Principles of Hydraulics - Driving Down the Road

Submitted By: Harold Z. Stofman
As a driver and motorist you may not know or appreciate that standard and basic principles of hydraulics are employed in the safe and standard practice of your automotive or truck transmission as you tool down the roads, highways and byways of your locale. What are these basic principles of hydraulics employed everyday in the reliable working of your tranny as it drives you down the street turning your auto’s wheels?
It seems that early in the seventeenth century, the French scientist Blaise Pascal proved that both force and motion can be transmitted by means and through confined liquids. Pascal discovered that simply put that the force multiplication in the hydraulic-pressure system was exactly as well as precisely the same as when the “mechanical advantage” was provided by gears and shafts. It appeared that the relationships between force and distance in multiplying torque were the same in both types of systems.
To understand the operation of an automotive automatic torque converter component and hydraulic-control systems in an automatic transmission of any automotive vehicle – be it car, truck, Sports Utility SUV vehicle or even large highway tractor trailer, a basic knowledge of hydraulics is required. Hydraulics is the science of liquids, such as oil and water. A hydraulic device uses the force that can be exerted by a liquid to transmit motion and to multiply force. One type of device is hydrodynamic such as the standard automotive “torque converter”. In it, the force of the fluid (hydro), in motion (dynamic) is used to multiply torque. A hydrostatic device, such as a valve in the hydraulic control system operates because of the in-compressibility of the fluid working on it. The valve moves as the oil pressure increases.
The next concept in line, towards and understanding of simple principles of hydraulics as they relate to your automobile’s automatic transmission system and its functioning and operations, is the concepts of in-compressibility of liquids.
For example if a gas, such as air, is put under pressure, the gas can be compressed and made to occupy a smaller volume of space. However, applying pressure to a liquid cannot change its volume. Why or alternatively why not? This is because liquids are incompressible.
However simply put, since liquids are not compressible, they can be put to work to transmit motion. How and what would be a simple example? A simple example and explanation would be two pistons in a cylinder with a liquid between them when the applying piston is moved a few inches into the cylinder, and then the output piston will be pushed the same distance along the cylinder. Yet think of this system another way so that useful work can be created and formed. A solid connecting rod could be substituted to get the same result and results. Henceforth the advantage and advantages of a hydraulic system is that motion can be transmitted between cylinders by a tube. As the applying piston is moved liquid is forced out of the cylinder, through the same tube and into tube number 2. Thus this causes the output piston to move in its cylinder.
At the end of the day or road it is these basic principles of hydraulics which allow your automatic transmission to transfer power and motion from your vehicle’s motor and power you down the road fast, reliably and predictably. Happy, safe and economical motoring.

Published At: Isnare.com