Belt Drive

[portacruise]

What I like about belt drives: easy to fix belt vulnerability issues on the spot with a spare belt if built with proper access; no viscosity efficiency losing oil bath and reduced concern on seal issues above water surface; its easy to change the gear ratio by exchanging cog wheels when fine tuning with different props; a spring idler can be used to keep proper tension as the system wears down; at least some systems are lighter weight and lower cost. Some of these also apply to chain drives. But of course they may take up more space and may not be rugged enough as traditional metal gearing in large applications. JMHO, have fun!

 

[brian eiland]

BELT drives in this underwater outdrive application would be so much more voluminous, in dimensions,.. and likely more of a challenge to fine tuning,...then sealing problems in this modern day with simply shaft seals,..no problem.

The silent chain application is the ideal way. I really don't understand why their are not more of them,... (any in production?)

With electric motors getting smaller and more powerful, you might even mount the electric motor right on top of that chain drive housing and have it powering one of the end shafts of the chain outdrive unit,...with a silent chain as well, or a set of spur gears.
Then you would have a relatively low profile drive unit you could locate in the floor of the main salon/cabin without noxious fumes of combustion engine(s) in the living spaces. Your electric power could be battery/solar/or diesel aux generated (outside living spaces).