Auxiliary Units; Hydraulic Governor; Vacuum Pump; Mechanical Rev. Counter - Rotax 914 F Maintenance Manual

10) Auxiliary units

10.1) Hydraulic governor

The engine version 914 F3 will be supplied with a fitted hydraulic governor for usage
with a constant speed propeller. The hydraulic governor is retrofitable on engine
version F2 and F4 by adding the drive kit for the governor in prop gear and crankcase
and oil supply line to governor and prop shaft (on F2 and F4 engine version).
on version 914 F2 the hollow prop shaft has to be exchanged also for the correct
one
on version 914 F4, the prop shaft can remain as it is of the same design with the
exception that the inside bore is plugged. After removeal of the plug the propeller
shaft is suitable for use with governor.
NOTE:
Transmission ratio crankshaft: prop shaft ................................ 51: 21,
Transmission ratio propshaft: governor ................................... 22: 29,
Direction of rotation ...................................................................
NOTE:
reduction ratio total .................................. anti-clockwise, looking at governor flange

10.2) Vacuum pump

It is possible to install a vacuum pump for employment of an inertial navigation system.
For that the drive kit for the vacuum pump has to be retrofitted on prop gearbox and
crankshaft.
NOTE:
Transmission ratio:

10.3) Mechanical rev. counter

Drive for the mechanical rev-counter from camshaft. The engine is prepared for later
installation of the rev-counter shaft. Just remove rev-counter cover, install retro-fit
items and connect flexible shaft to indicating instrument.
The total transmission ratio from crankshaft to flexible shaft

10.4) External Alternator

The internal generator can supply approx. 20A DC. To meet an increased energy
demand, installation of an external 40A alternator is possible, either at serial produc-
tion or as retrofit kit later on.
Date
Page
1997 02 01
66
Installation of both, the hydraulic governor and vacuum pump is not
possibel.
The reduction ratio between crankshaft and vacuum pump or hydrau-
lic governor is 1,842 i.e. these units run with 0,54 of engine speed
Installation of both, the vacuum pump and hydraulic governor is not
possible.
Vacuum pump and hydraulic governor are driven the
same way and therefore have the same total reduction
ratio. See hydraulic governor.
Main
914 F
Reference
i = 2,4286
i = 0,7586
i = 1,842
i = 4
Modification no.
- 0 -