Page 204 - Automobile Mechanical and Electrical Systems Automotive Technology Vehicle Maintenance and Repair (Vehicle Maintenance Repr Nv2) by Tom Denton

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188 Automobile mechanical and electrical systems

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Figure 2.217 1, Vane adjustment solenoid valve; 2, atmospheric pressure; 3, vacuum;
4, adjusting ring; 5, vanes; 6, vanes; 7, turbine; 8, turbine; 9, vacuum diaphragm unit;
10, electronic control module (ECM). (Source: Ford Motor Company)

Figure 2.218 Twin Roots blowers

Figure 2.219 Cutaway supercharger

turbocharger. However, they are driven by belts and gears from the engine
crankshaft. Vane radial superchargers have been used but are less popular.
The Roots blower uses two or three lobe intermeshed rotors to pump air. The
rotors have helical rotor vanes to reduce noise and improve effi ciency. The rotor
vanes are driven and matched together with a pair of gears, so that they rotate
in mesh with each other. They run on ball or needle roller bearings at each end
of the rotor spindles. They must be lubricated with high-performance grease or
synthetic oil in the bearing cases.