Neil
New Member
Neil Hintz, Autoflight Ltd. We build the new three gear, gearboxes Titan use now on their V6 engines. This design is based on our Subaru H6 heavy duty 300 unit with an extra gear in the middle. Shafts are short with diameters large, input gear has no join and is one piece shaft and gear. Output shaft has a tapered joint, gear to shaft ( keyed ) with a large spring type washer under the retaining nut to hold the taper tight through torsion and temperature changes. Input gear and out gear design have been in production for approx four years now, only one failure known, on a Rotamax rotary engine ( 120 hp ). This unit was used with a long driveshaft of unknown frequency ( we didn't know what was going to happen ).
The three gear units are operating satisfactory here in NZ and at Titan although I think the highest hour three gear unit has only 100 hour on it so far. We use a rubber connection from crank to gearbox, I'm not a fan of one way clutches. Some Autoflight Subaru gearboxes in Australia have nearly 1000 hours on ( 160 HP units ), Oil changes every fifty hours. Double row angular contact bearings used on both input and output shafts with rollers opposite to allow for expansion. Gears are EN39B case hardened to 60R, alloy case is CC601 heat treated to T6, output shaft is 4140. Gears are set with minimal backlash, 11 degree helix, enough to shut them up. I am happy to answer questions you may have, if I can.
The three gear units are operating satisfactory here in NZ and at Titan although I think the highest hour three gear unit has only 100 hour on it so far. We use a rubber connection from crank to gearbox, I'm not a fan of one way clutches. Some Autoflight Subaru gearboxes in Australia have nearly 1000 hours on ( 160 HP units ), Oil changes every fifty hours. Double row angular contact bearings used on both input and output shafts with rollers opposite to allow for expansion. Gears are EN39B case hardened to 60R, alloy case is CC601 heat treated to T6, output shaft is 4140. Gears are set with minimal backlash, 11 degree helix, enough to shut them up. I am happy to answer questions you may have, if I can.