What type of PSRU does Vesta Inc. make?
The PSRU (Prop speed reduction unit) or chain drive is manufactured by Vesta Inc. The PSRU chain drive is an adaptation of the Morse HyVo chain and sprocket design pioneered by Fred Geschwender. The chain, bearings and seals are lubricated on the inside by a pressure oil flood. The PSRU housing is machined out of billet aluminum. off the shelf tapered roller bearings are used to provide either a Tractor or Pusher style of thrust. The Rockwell hardened shafts are holllow and are hydraulic capable to drive a constant speed propeller. I recommend a 2000 hr. TBO, at which time the chain, bearing, and seals are replaced (apx. $350 off the shelf parts). Unlike gears, the HyVo chain runs 80% cooler and does not produce the same kind fictional heat, nor does it have the same kind of torsional vibration problems.
