Pratt & Whitney Rzeszów S.A.
MAINTENANCE MANUAL
PZL-10W ENGINE
1992.08.28
73-22-01
Page 15
Export Control Classification: PL/UE 9E999
Th e sp ri ng te nsi on an d th er eb y t he f uel ca pac it y va lu e del i ve re d to th e s tar ti ng in jec to rs is t o be
a dju st ed b y th e H7 a dju sti ng sc re w.
( 20 )
Cons ta nt p ress ur e va l ve .
Th e co nst an t pr essu re val ve con sis ts of t he sl ide p ai r and s pr ing . Th e fu el p ress ur e inc re ase on
t he le ft si de of t he sli de ,, ab o ve th e val ue adj us ted b y t he sp rin g te nsio n, ca uses t he sli de mo tion
t o wa rds t he r igh t and t h e f l o w hol lo w co ve ri ng .
Th is mo veme nt la sts up to t he mo men t, whe n the p re ssu re i n th e c ham be r o n the l ef t o f th e sl ide
a c h i e ves the c ons tan t valu e adj ust ed b y t he sp rin g t e n s i o n .
( 21 )
S upp or t val ve.
Th e s upp o rt va l ve c ons ist s of th e sli de p ai r an d sp ri ng . Th e f uel pr essu re i n t he e le va te d d rain
m ain is a c on tr oll ing p ress ur e. Th is pr essu re is co nst an t. In t he case , th is p ress ur e i nc reases,
t he sl ide o f th e sli de pa ir mo ves d o wn wa rds an d op ens t he fl o w h o l l o w. Th e fu el e xc ess is
d ra in ed on t he l o w p r e s s u r e s i d e .
( 2 2 )
Control lever (CL).
The CL assembly consists of the shaft with the toothed ring matching with the throttle valve, disc and lever.
The shaft is bedded in the casing of the fuel metering pump.
The disc is fastened to the casing by three bolts.
The lever position adjustment in relation to the shaft (after the tuel capacity adjustment of the throttle valve) is performed by
the T11 perpetual screw. The indicator shows the lever turn angle value on the scale positioned on the disc.
The runner with protrusion adjusted by the T1 3 washers is fastened to the lever. At the lever turn in the range of 100 ÷ 110°,
the runner causes the angle lever turn, which pressing on the push rod of the electrohydraulic servo valve causes
disengaging of this valve of the operation.
At the same time, the cam mounted on the lever, through the push rod, causes the shifting of the power turbine rotational
speed limiter. The lever has two angle limiters: the T14 for α
C L
= 0° and the T1 5 for α
CL
= 120°.
( 2 3 )
Check valve.
The check valve, one way. is situated in the drain main of the fuel metering pump betöre the sealing assembly of the gear
pump drive.
The valve duty is to make impossible the pressure increase in the sealing assembly at the moment when the drain valve
opens after the engine shutdown.
