QUESTIONS AND VERIFIED
ANSWERS|100% CORRECT|GRADE A+
What does a mechanical engineer do? - ANSWER applies the principles of physics and material science
for analysis, design, manufacturing, and maintenance of mechanical systems
What does mechanical engineering involve? - ANSWER the production and transmission of heat and
mechanical power for design, production, and operation of machines and tools
examples of things mechanical engineers work on - ANSWER biomechanics, crawler transport, robots,
acoustics,
object of developing vehicle - ANSWER fastest, lightest, heaviest load
Gears - ANSWER cogged wheels fixed to shafts that mesh together resulting in power transfer; used to
change speed, torque, or direction
Pitch Circle - ANSWER At the effective diameter, D
N - ANSWER number of teeth
Speeds of gears vary - ANSWER Inversely, because:
V1 = 2πr1ω1 and V2 = 2πr2ω2
V1 = V2 because the gears are touching
so r1w1 = r2w2
Torque varies - ANSWER Directly
Gear Ratio - ANSWER ratio of the output gear diameter to the input gear diameter
, (N out) / (N in)
Spur Gears - ANSWER simple, cheap
operate on parallel shafts
Helical gears - ANSWER -more efficient, better design, smoother
-develops end thrust which can be overcome by the use of thrust bearings
-used for higher velocity
BEVEL and MITER gears - ANSWER -used for right angle drives
-high efficiency
-MITER gears have 1:1 ratio
-application: rear differential
Differential - ANSWER -when both wheels can turn, they have the same velocity
-when one wheel cannot turn, the other speeds up
Planetary gears - ANSWER -high gear ratios in compact, flat space
-many configurations are possible
-ring, planet, sun, carrier
Rack and Pinion - ANSWER -linear gear and circular gear
-transfers rotational motion to linear motion
WORM gears - ANSWER spiral and round gear
Motor - ANSWER transfers electrical power to rotational mechanical power
-by Lorentz force: current passing through a conductor in a magnetic field results in a force