Originally Posted by
lomapaseo
The thrust bearings are typically ball bearings. The only time I heard of conical rollers were the very old RailRoad adds of the 40's. Things go tits-up when a cage breaks and the balls migrate away from the radial load. Fortunately the shafts find a home cuddling inside some other bearing compartment until the plane lands.
It's like a bowling ball inside a washing machine. Best not to be in the same room with it.
I think there is more to the original question. Axial thrust impinging the rotating mass of a single spool turbojet is a simple question, something the OP undoubtedly has the answer to. “....I have spent years studying the SR-71, and have communications with the engine builder...”
If the purpose was to tease out some conjecture, (and I have no way of knowing...), I’ll offer some thought.
The purpose of propulsion is to meet and overcome drag, with enough left over to accelerate the airframe.
A percentage of inlet air is continuously dumped (evacuated) from the dorsal airframe bleeds. That shows the design is competent in regards to drag, thrust, and excess power.
The rotor, compressor, and turbine are functionally integrated in a solid structure. Conceivably, with sufficient drag at the inlet, this propulsive design could operate as Ramjet, prior debate notwithstanding.
If it did, it would demonstrate the reversal of axial thrust at the rotor. The inlet air would exceed in Force the effort of the turbine, and force the rotor forward, into its thrust bearings with forward force. At this point in the transition to our ramjet, the turbine and its compressor adjunct would be superfluous, even deleterious to the engine’s current “configuration”. The inlet (drag) overpowers the aft turbine, driving the compressor and reversing output of the turbine.
The inlet stators have trailing edges that articulate from “adding camber” to “free stream” at high engine output; the swirl contribution is unnecessary at high speed.
Imagine that the compressor blades and turbine could be “subtracted” from the design in transition to pure Ramjet? If not remove, then “feather” the blades.
Make no mistake, that is exactly what the six bypass tubes accomplish, only partially. Bypassing the bulk of the compressor, the diffuser, the combustion chamber, and dumping inlet air directly into the afterburner section, it is a “partial” ramjet system.
If correct, I am sure this is not new to the OP. But it is new to me, just trying to catch up to those further along the learning curve.
much respect to
megan,
concours