Raymarine autohelm type 1 hydraulic pump/drive repair

[deblen]

This pump uses a permanent magnet motor,I believe.
Quite often when taking these motors off the driven unit,the armature wants to come along too. It then feels like a springy force is holding the motor together.
It's best if you can get to the output end of motor & loosen any setscrews,etc,that are attaching motor o/put shaft to driven unit.
You have to do it eventually anyway.
Be cautious about banging on these PM motors-the magnets are very brittle & are only glued to motor casing.
A small piece of magnet could be source of noise.
/Cheers/Len

[daveNZ]

Many thanks....So I've succeeded, to a point. Stupidly I assumed the remaining machine screw holding he motor would knock out, but it is threaded in the pump housing (middle section in above photo) and also in the motor, so I had to wiggle it loose the hacksaw the thing. (Only took 2 hours) The motor then came off easily, and is merely a sealed unit, with a slotted drive (like a water pump">raw water pump drive) which passes through a regular oil seal in the pump housing, and drives a nylon? piece that in turn drives gears at the other end, ( right section in my photo.) in that end section one gear turns another, which turns nothing else!! I fail to see what actually pumps hydraulic fluid. There are many small passages that look to me like lubrication channels. I have no idea how the hydraulic side of this works, but the noise is definitely the motor bearings. So I'm assuming the actual pump is fine, all looks clean etc. the motor actually feels quite solid, and now runs on the bench but is very noisy so need to change the bearings if I can.

Problem now is I can't get the two screw holding the motor together, apart. They are hemispherical headed and the nut on the other end is impossible to get at, and is seized. Can't even get at the heads to cut a slot etc. all I can think of is carefully cutting off the nuts with an angle grinder!!

The joys of buying a 12 year old boat, I've had to work on nearly every thing that moves, but I do know it very well now, which is all good!

Thanks for the input, appreciate your thoughts.


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[belizesailor]

Originally Posted by daveNZ

2 fastenings from middle section to motor are out, and 4 fastenings from right hand section to the middle section are out, but none of this wants to come apart.
I can lever the motor away from the middle section by 2 mm or so, but the middle and right hand sections are solid. belizesailor have you actually taken these apart? Should the motor come away cleanly? Like always this will be obvious and easy once done!

Yes, normally it comes apart easily. Once the bolts are all removed all these components normally come apart easily...no prying or pulling required. The pump head main body (middle component) is a solid piece of machined aluminium. The motor body is ferrous metal, so I suspect the two have galvanically welded together. Maybe some PB Blaster (or similar) at the joint and tapping the motor housing with a hammer might crack them loose.

The motor shaft is short and inserts into a short notched shaft in the pump head. This is a loose fitting coupling, so aside from the bolts there is nothing to normally offer any resistance to the sections coming appart.

In your pic the far right piece (smaller section of the pump) houses the impellers. The middle section is the pump head main body housing check valves and threaded ports for hyro line connections. Once the allen head blots on the small part of the pump head are free this part should easily come off.

Whatever your end solution, it looks like the pump needs better protection from salt water.

[daveNZ]

Thanks again. Yes exactly as you said internally. And yes it is mounted directly under a deck fitting that was leaking, so nice build up of white salty mush, and the aluminium has this tarnished coating on top. Rust on the motor a well. There are two locating pins between the two aluminium parts, these took a lot of persuading to separate. All cosmetic though and clean inside.
I asked the dealer last year about servicing these pumps and they said leave it alone if it is working. I think there is some merit though in servicing and maybe replacing bearings etc, especially after 12 years since install (but only 700 engine hours.

water pumps will be next then!


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[belizesailor]

"If it aint broke dont fix it" only goes so far. If its to the point of being noisy something is gonna fail soon, so time to rebuild or replace.

[daveNZ]

Problem found! As 'Len?" suggested, cracked and dislodged arc magnets. Both magnets are cracked and 3 of the 4 halves are loose. Explains why motor would not turn at all and then later did run, if noisily. Bearings are solid (i.e. no balls or rollers) and seem ok. Assume they don't need any lubricant although they were moist.

Will try and find replacement magnets and glue them in. Any point in gluing the broken ones back as a last resort? I assume that a cracked magnet will act as two magnets in terms of polarities, and may be less efficient??

The motor as is draws about 7.5 to 8 amps without driving the pump.
Nearly there. Still trying to avoid $1150 for a new one.

[deblen]

Originally Posted by daveNZ

Problem found! As 'Len?" suggested, cracked and dislodged arc magnets. Both magnets are cracked and 3 of the 4 halves are loose. Explains why motor would not turn at all and then later did run, if noisily. Bearings are solid (i.e. no balls or rollers) and seem ok. Assume they don't need any lubricant although they were moist.

Will try and find replacement magnets and glue them in. Any point in gluing the broken ones back as a last resort? I assume that a cracked magnet will act as two magnets in terms of polarities, and may be less efficient??

The motor as is draws about 7.5 to 8 amps without driving the pump.
Nearly there. Still trying to avoid $1150 for a new one.

There you go!!

You really need a new or good used motor.The pump sections last much longer.
I found this # Raymarine Autopilot Hydraulic Unit 12v Type 1 Motor A18109 Spares Auto Pilot | eBay

Fits current M81120 pumpset. Probably fits your Axxxxxx model,but verify that.

I presume they use some type of epoxy to glue the magnet sectors in place. If the sectors are all complete,though cracked/broken in 2 pieces, I suppose you could try re-gluing. But if one or more is missing a piece,I suspect the motor would run out of balance,& destroy itself.
Never tried this repair & wouldn't count on it lasting long,but desperate times......

Shop ebay US & UK. The Raymarine Type 1 are available USED quite often in the US$ 200 range for complete pumpset.
I know courier shipping is the killer for NZ. USMail may be more reasonable,& if you buy from a private seller with a 99.9% rating,they will usually ship mail.
Good luck/ Len

[deblen]

You might check these folks out. They have been making A/P pumps for a variety of mfgrs for many yrs

Reversing Pump Family | OCTOPUS


http://www.defender.com/category.jsp...687&id=2028715

[DeepFrz]

There are lots of new motor pump combinations that would work on eBay asking $500. to $700. You may be able to find used but then you don't know the history.

[belizesailor]

Originally Posted by deblen

There you go!!

You really need a new or good used motor....

+1. Damaged or detached permanent magnets are usually new motor time.

I suppose you could try and fair them and epoxy them back in place, but for something as important as AP I would feel a lot more confident with a new motor.

[daveNZ]

Many thanks for the input again guys. I agree a new motor would be ideal. My boating is coastal cruising with other boating traffic and few passages over 3 hours so AP is nice but not essential, and mostly used while doing some small job. I would much rather spend the $ on new house batteries and a smart regulator for the alternator that I'm also repairing.
I'll let you know if I replace the magnets and if it lasts!! Cheers.


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[DeepFrz]

No personal experience but I have read on the forum of people epoxying in loose and broken magnets in their wind generators. They seemed to work okay after. I have no idea how well or for how long though.

[mrm]

Originally Posted by daveNZ

I agree a new motor would be ideal. I would much rather spend the $ on new house batteries and a smart regulator for the alternator that I'm also repairing.

Dave, have you considered an automotive DC permanent magnet motor? Those can be had for a song from most car wrecking sites and the mechanical fit issue can usually be solved by a friendly workshop. Perhaps try a windshield wiper motor? They are quite robust and well sealed.

[daveNZ]

No I haven't considered other motors. I assume the speed (and torque) is important, to drive the pump at approx. the same speed. The drive shaft goes through a lip seal so motor to pump connection might be non-trivial and therefore expensive. I think a new motor would be a better bet.
But, I'll be regluing my magnets, the polarity is radial, a broken magnet is not two magnets in terms of North-South twice in the length of the previous one magnet. It is all one pole at the inner face and other pole on the outer face, so I reckon it will work fine. (It 'was' running with the broken magnets).

Glue....I've spoke to two magnet suppliers, each recommended different Loctite products.
I was going to use a 5min araldite. I then bought the 401, then later heard of the 324. Any thoughts?
Loctite 401 seems like superglue to me. Will it stand up to vibration?
Loctite 324 strength of an epoxy but quick setting.


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[mrm]

Originally Posted by daveNZ

I think a new motor would be a better bet.

Me too, but since you indicated other expenses of a higher priority, I offered a workaround..

But, I'll be regluing my magnets.

Glue....I've spoke to two magnet suppliers, each recommended different Loctite products.

If I were doing that, I would use two glues.

First I would reassemble the pieces to as much an original shape as possible. For that I would use the thinniest superglue I could find and only very little amounts. This step is not for strength, only to keep pieces joined for the next step.

Then I would use an epoxy glue to permanently glue the reassembled magnets in.

As for bearings they are probably bronze and somewhat self-lubricating, but it helps to wet them with a drop of light machine oil.