this post was submitted on 27 May 2024
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Hello lemgineers!

I'm working on designing a claw that can be operated underwater. The plan is to use a linear actuator in a waterproof housing. The main issue is allowing the shaft to slide through without causing a leak. What's the best way to go about this?

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[–] [email protected] 4 points 7 months ago* (last edited 7 months ago)

If you need a shaft to slide through the wall of your housing, Google "shaft seal" or "oil seal." The seal usually presses into a hole in your housing, so you will want the housing to be metal rather than plastic.

https://www.mcmaster.com/products/shaft-seals/

A dynamic seal like this is going to be difficult to implement. The shaft will need to be very smooth and carefully aligned to the housing. Some small amount of water is likely to get past the seal.

I'm with @[email protected]. Consider other ways to actuate your claw that don't require moving a part through the housing wall. I'm addition to pneumatic or hydraulic actuators outaide your housing, here's an idea using magnets and screws:

https://org.osu.edu/osu-uwrt/2022/04/11/underwater-claw-development/