Control Arms, Shafts and Bearing Housings
Unique elastomer bearing replaces needle bearing
McFarlane's elastomer bearing is assembled with
tension between the mating surfaces. This tension prevents
micro-movement and its related metal erosion. The bearing contact area
that transfers vibration motion from the heat box to the butterfly shaft
is hundreds of times greater than that of the original needle bearing.
This large surface effectively prevents localized metal erosion.
- Absorbs shaft and butterfly vibration
- Eliminates needle bearing failures
- Increases service life of all components
- Direct replacement for original parts
Proven Design
- Tested to over 700,000 cycles while exposed to avgas, heat and vibration without any change in performance
- Extremely rugged and wear resistant in high temperature and fuel environments
Convenient
- Discontinued part numbers through the factory are now manufactured by McFarlane
- Shafts, arms, bearing housings, monel rivets and roll pins are also available separately or in kits
The carburetor heat box suffer more from engine vibration than other
parts of the engine installation due to the distance of its location
from the center of the engine. Engine vibrations, which are small back
and forth movements of the engine about a point of rotation in the
engine, become larger and more severe as the distance increases from the
center of these movements. A fraction of an inch of engine movement
near the center of the engine could result in over an inch of movement
in an attached component that is located a considerable distance from
the center of the engine. This phenomenon can be visualized by imagining
what would happen if a five foot broom handle was solidly attached to
an idling aircraft engine. The far end of this broom handle would
oscillate wildly back and forth as the engine moved slightly. This is
similar to what is happening to the carburetor heat box. Normal engine
vibrations are amplified by the distance (arm) from the center of the
engine.
Ordinary needle bearings are not well suited for this high vibration
environment as they concentrate the energy of vibration movement to the
very small area where the needles contact the heat box butterfly shaft.
This concentrated kinetic energy results in metal loss and grooves being
worn into the shaft with eventual failure of the bearing system. Needle
bearing failure can lead to ingestion of loose needles into the engine
induction system and cylinders.
Unique elastomer bearing replaces needle bearing
