Checking The Splines; Gear Set Check (Gears) - Rotax 915 i A Series Maintenance Manual

CHECKING THE SPLINES

There are 4 essential splined shaft connections in
the gearbox.
1. Propeller shaft to damper clutch.
2. Torsion shaft to propeller shaft.
3. Torsion shaft to overload clutch.
4. Crankshaft to drive gear GB 07 / GB23.
To check the splines, determine the tooth widths at
the tip circle of the respective inner or outer gear-
tooth system. The smallest value in each case is
significant.
Figure 6.44
72–10–00
Page 26
June 01 2019
BRP-Rotax
MAINTENANCE MANUAL HEAVY
Procedure
Step
1 Check crankshaft to drive gear, see
Chapter 72-10-00 section wear
2 Check the splines of propeller shaft, tor-
sion bar, overload clutch and damper
clutch visually for damage and wear. If
the tooth flank is worn, replace the part.
The spline pair propeller shaft and damp-
er clutch has clearance from new.
NOTE
The torsion bar must have tight fit into propeller
shaft and overload clutch.

GEAR SET CHECK (GEARS)

The gear set is checked to identify any damage to
the gear-tooth system.
ATTENTION
Check all the tooth flanks for any damage or
pitting.
NOTE
If the gearbox is installed, it is also possible to
check the gear set using an endoscope. This
must be done in such a manner that an exact
assessment of the tooth flanks is possible and
requires experience.
Pitting
Pitting is damage which is attributable to fatigue of
the material. As far as is known today, this is caused
when the Hertzian stress permissible for the material
in question is exceeded, the tangential stress on the
surface (friction stress) and temperature stress. As
well as the material and the heat treatment of it, the
surface quality and structure, surface treatment and
lubricant (viscosity at operating temperature and ad-
ditives) are also important.
NOTE
The likely location of pitting formation is the de-
dendum flank of the driving gear. Therefore, be-
gin by checking the drive gear.
limits.
Effectivity: 915 i A Series
Edition 0/Rev. 1