The Suspension System On A Car ExplainedWritten by Kevin Schappell
"Suspension," when discussing cars, refers to use of front and rear springs to suspend a vehicle's "sprung" weight. The springs used on today's cars and trucks are constructed in a variety of types, shapes, sizes, rates, and capacities. Types include leaf springs, coil springs, air springs, and torsion bars. These are used in sets of four for each vehicle, or they may be paired off in various combinations and are attached by several different mounting techniques. The suspension system also includes shocks and/or struts, and sway bars. Back in earliest days of automobile development, when most of car's weight (including engine) was on rear axle, steering was a simple matter of turning a tiller that pivoted entire front axle. When engine was moved to front of car, complex steering systems had to evolve. The modern automobile has come a long way since days when "being self-propelled" was enough to satisfy car owner. Improvements in suspension and steering, increased strength and durability of components, and advances in tire design and construction have made large contributions to riding comfort and to safe driving. Cadillac allegedly produced first American car to use a steering wheel instead of a tiller. Two of most common steering mechanisms are "rack and pinion" and standard (or recirculating-ball) systems that can be either manual or assisted by power. The rack and pinion was designed for sports cars and requires too much driver muscle at low speeds to be very useful in larger, heavier cars. However, power steering makes a heavy car respond easily to steering wheel, whether at highway speeds or inching into a narrow parking place, and it is normal equipment for large automobiles.
| | A Cars HVAC SystemWritten by Kevin Schappell
Not only do we depend on our cars to get us where we want to go, we also depend on them to get us there without discomfort. We expect heater to keep us warm when it's cold outside, and air conditioning system to keep us cool when it's hot. We get heat from heater core, sort of a secondary radiator, which is part of car's cooling system. We get air conditioning from car's elaborate air conditioning system. Despite its relatively small size, cooling system has to deal with an enormous amount of heat to protect engine from friction and heat of combustion. The cooling system has to remove about 6,000 BTU of heat per minute. This is a lot more heat than we need to heat a large home in cold weather. It's good to know that some of this heat can be put to useful purpose of keeping us warm. Air conditioning makes driving much more comfortable in hot weather. Your car's air conditioner cleans and dehumidifies (removes excess moisture), outside air entering your car. It also has task of keeping air at temperature you select. These are all big jobs. How do our cars keep our "riding environment" way we like it? Most people think air conditioning system's job is to add "cold" air to interior of car. Actually, there is no such thing as "cold," just an absence of heat, or less heat than our bodies are comfortable with. The job of air conditioning system is really to “remove” heat that makes us uncomfortable, and returns air to car's interior in a "un-heated" condition. Air conditioning, or cooling, is really a process of removing heat from an object (like air). A compressor circulates a liquid refrigerant called Refrigerant-12 (we tend to call it "Freon," a trade name, way we call copy machines "Xerox" machines). The compressor moves Refrigerant-12 from an evaporator, through a condenser and expansion valve, right back to evaporator. The evaporator is right in front of a fan that pulls hot, humid air out of car's interior. The refrigerant makes hot air's moisture condense into drops of water, removing heat from air. Once water is removed, "cool" air is sent back into car's interior. Aaaaaah! Much better. Newer cars have R-134 as refrigerant, but work in same way as R-12.
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