Thanks Vance. Would you happen to know why the brushes welded at depth? --Doug J
In a message dated 11/19/2006 8:02:41 PM Central Standard Time, vbra676539@aol.com writes:
Doug,
I was thinking more along the lines of 1000 METERS plus. The old Alvin electro-hydraulic package for propulsion was under heavy load and developed a nasty habit of welding brushes at depth. They went brushless, ditched the hydraulics, and the problem went away. The HYCO motors were custom made with square wire in the windings for maximum contact, and didn't have that problem. The Perrys and the JSLs use hard cans all the way to 3000 feet, and so were never faced with it in the first place.
Vance
-----Original Message-----
From: DJACKSON99@aol.com
To: personal_submersibles@psubs.org
Sent: Sun, 19 Nov 2006 8:15 PM
Subject: Re: [PSUBS-MAILIST] Oil Compensated Thursters
Vance: Thanks for the reply. You said "Oil compensated DC motors work just fine at moderate depths." What problems are encoutered below 1000 feet?
Thanks ---Doug J
In a message dated 11/15/2006 10:21:24 PM Central Standard Time, vbra676539@aol.com writes:
Oil compensated DC motors work just fine at moderate depths. Alvin had problems originally with brushes arcing, but he Hymak 5 hp motor used by Hyco on nearly everything they built was a serious workhorse. You get to tear it down and change brushes periodically as they wear faster, and they'll get the oil dirty, so you'll have to watch that. I was on Karl Stanley's web page last night and it looks to me like his Idabel is using about a case of trolling motors, and they must be compensated, as the sub is rated for 3000 foot service. Maybe we ought to ask him what the secret is, if any.
Vance
-----Original Message-----
From: DJACKSON99@aol.com
To: personal_submersibles@psubs.org
Sent: Wed, 15 Nov 2006 10:35 PM
Subject: [PSUBS-MAILIST] Oil Compensated Thursters
Can anyone support this statement: "Scripps has tried to fill the DC motors with oil, but the oil gets between the brushes and the commutator, where the insulation properties of the oil causes problems. Although it would be possible to use high voltage to break through the oil film, the high voltage is a safety hazard for the divers."
I was thinking about 24 or 36 volt oil compensated brushed trolling motors, but after reading the above I looked and could not find any examples of oil compensated brushed motors under 100 volts.
What are your experiences and thoughts?
Thanks
--Doug J
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