Gearbox pressure buildup and breather calculations

[cybanical]

I'm designing a new gearbox that operates submerged in water, and working on calculating how much oil I need, and if I need a breather for the vapor pressure buildup (hoping not).

What references exist for determining oil type and level required?

What references might you have for determining breather requirements?

My best guess is to estimate efficiency losses in drivetrain, use that to calculate heating in the oil bath, and vapor pressure change from that heating. From that pressure change I can determine if either my shaft seals can withstand this pressure, or I need to accommodate some volume differential. BUT, I was wondering if there's a shorter path estimate than stepping through each of those calculations?

thx

 

[Sealing guy]

Quite an interesting thread. Were you able to decide on oil and breather?
Shaft seals I believe you may have to go for material that is compatible with oil as well as water.
I would probably look for PTFE based rotary seals.
Seal lip can be designed to withstand the pressure from internal media. Also as this gearbox is submerged in water, I believe you already have good heat dissipation. Nevertheless, it is best if you can provide tandem seal arrangement so primary seal can seal the oil within system and secondary seal will avoid water seeping in.
Thanks.

 

[Tmoose]

OP's last login was on Wednesday, October 25, 2023.

Maybe truly last, unless he set "Notify me".