In order to achieve high speed the materials of construction
for the rotating components have to be of a high strength to density
ratio and the rotor assembly,
and hence its individual components, have to be manufactured to very
close tolerances in order to minimise the imbalance . The rotor assembly
consists of the three blades, the rotor hub, three geared bearings and
threephase drives for adjusting the pitch of the blades.
Late model brake systems on most cars and light trucks utilize disc
brake rotors on the front, and brake shoe drums on the rear. Rotors and
drums are both very important to the effectiveness of vehicle braking.
The advantage is consistent, quiet, confident braking. Drums and rotors
must dissipate heat and stand up to continuous contact with water, road
grit, and abrasives.
On more thing , about helicopters , the main rotor and the rotor head of them are discussed under the rotor head section , because their functions are closely ralated . Neither has a function without the other . The main rotor or rotary wing on the H-3 has five identical wing blades. Other helicopters may have two, three, or four blades. A typical wing blade is shown in figure 1-17. The rotary-wing blade is made of aluminum alloy, except the steel cuff by which the blade attaches to the rotor hub. The main supporting member of the blade is a hollow, aluminum alloy extruded spar, which forms the leading edge.