Transmission Gear for Automobile
• Describe the component and its use.
A transmission provides speed and torque conversions from a rotating power source to another device using gear ratios. The most common use is in motor vehicles, where the transmission adapts the output of the internal combustion engine to the drive wheels. Such engines need to operate at a relatively high rotational speed, which is inappropriate for starting, stopping, and slower travel. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process.
A transmission will have multiple gear ratios (or simply "gears"), with the ability to switch between them as speed varies. This switching may be done manually (by the operator), or automatically. Directional (forward and reverse) control may also be provided.
In motor vehicle applications, the transmission will generally be connected to the crankshaft of the engine. The output of the transmission is transmitted via driveshaft to one or more differentials, which in turn drive the wheels. While a differential may also provide gear reduction, its primary purpose is to change the direction of rotation.
<Source: http://www.wikipedia.org/ >
• Drawing of component.
• Determine the two most critical mechanical properties.
< Made by pwrangshion (Internet Community VPD's Nickname) >
Transmission is comprised of many gears. These gears work actually useful for automobiles. So this gear's mechanical properties are important. Transmission hulls is less important than gears
As image, Gear center and tooth are load big stress about 6,000 psi(about 422kgf/cm²). So Transmission's gears have big strength and Toughness.
• Determine methods to measure the two most critical mechanical properties.
Transmission usually made by aluminum composite steel. So we need aluminum composite steel test sample. And we carry out torsion, tensile, fatigue test. Strength is expressed by the tests. And Toughness is combination of strength and plasticity.
< Source: http://www.wikipedia.org/ >
a. compressive test b. tensile test c. torsion test
< Source: http://www.uwinint.co.kr >
Fatigue test
• Determine uncertainty or limitations of the mechanical property values.
Corrosion resistance, Harness, Elasticity, Plasticity, Brittleness, Ductility, Malleability did not considered.
Especially, corrosion resistance is important to transmission. Transmission is not protected. Transmission is located under the automobile. So it did not protected environment. Likely, pools, air, and so on. It is easy to corrosion. Transmission is important to automobile. At that reason corrosion resistance is important factor.
