Vedeneyev M-14P, Maintenance Manual

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SUPERCHARGING - DESCRIPTION AND OPERATION
1. GENERAL
Ambient air density drops with altitude which decreases mass of air supplied to the cylinders, hence engine
power at constant speed and constant position of the carburetor throttles.
To increase engine power to the desired level near the ground and maintain nominal power up to the
design altitude, the M-14P engine is equipped with a centrifugal blower with positive one-speed drive.
Apart from increasing power, the blower promotes mixing of fuel with air and more uniform distribution of
the mixture among the engine cylinders, which is particular important when starting the engine.
During operation of the engine, the working mixture from the carburetor is sucked into the blower space
through an oval port in the lower boss of the mixture collector, is directed to the impeller blades and is urged by
centrifugal forces to flow at a high velocity through the passages defined by the impeller blades and mixture
collector wall from the center to periphery and then to the diffuser.
2. CONSTRUCTION
The blower comprises mixture collector (1) (Ref. Pig. 1), diffuser (24), impeller (5)» drive with coupling (29)
and sealing parts.
2.1. MIXTURE COLLECTOR
The blower mixture collector (Ref. Pig. 2) cast of aluminium alloy is attached to the rear part of the
intermediate casing by studs driven into the latter. The mixture collector has a cast space (release manifold with
nine equally spaced release branch pipes) with grooves for rubber sealing rings and thread for the intake pipe
sealing nuts.
Eight bosses forming the branch pipes have lugs with holes for engine-to-frame attachment bolts. The
thrust bearing of the accessory drive shaft and blower deflector are attached by four studs at the center of the
mixture collector front wall.
Pressed in the central hole of the mixture collector is a steel bushing serving to support the rings of the oil
seal bushing of the blower front seal assembly.
The blower seal assembly is used to preclude ingress of oil into the suction system of the engine.