Thanks T,
An honest man may be hard to find, but
appreciated by all who know him.
Tommy<><
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Tracy Crook
Sent: Tuesday, November 16, 2004
11:11 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Post
Mortem on Steve Brooks RD-1B
Total time on drive
was 20 hours. Steve noticed the problem as an oil leak from
the input shaft oil seal. Internal inspection showed the input
shaft thrust bearing roller cage which is a polymer cage to be partially melted
and most of the rollers were out of the cage. Overheat was the obvious
cause of cage failure. Rear race of bearing was seized on input shaft and
was 'blued' from heat. This allowed the shaft to move back and contact the
adapter plate. All sorts of nastiness resulted from this but the details
are not as important as the root cause. Amazingly, the drive continued to
operate normally but the time between roller cage failure and discovery of the
problem is unknown.
The oil passage from
the input shaft pilot bearing to the thrust bearing was found to be clogged and
no oil was getting to the thrust bearing (except for incidental splash).
What caused the clog has not been determined. I will attempt to carefully
grind away the input gear and see what it was as time permits.
The rear race was
spinning against the adapter plate and acting as the thrust bearing while being
lubricated only with splash. That Mobile 1 is amazing stuff!
A careful inspection
of the gears showed no evidence of damage or wear.
Corrective
action: Replaced the input shaft assembly and thrust bearing,
installed nylon snubber/spacer to bring input shaft endplay into spec.