PSS Shaft Seal
The stainless-steel rotor is fit on the shaft in front of the carbon flange. The stainless-steel rotor is used to compress the bellow before the rotor is secured to the shaft with set-screws.
This compression (pre-load) maintains constant contact between the two flat faces of the stainless-steel rotor and carbon flange, allowing the PSS to compensate for the variable fore and aft movement due to propeller thrust.
The carbon flange is over-bored to the shaft diameter allowing it to “float” around the shaft and thus compensate for most misalignment and vibration problems.
The stainless-steel rotor is sealed to the shaft by two O-rings that are recessed into the bore of the collar.
These O-rings rotate with the shaft and stainless-steel rotor and do not experience wear during operation.