Hydraulic Oil Grades, 32 vs 46 (Hot vs Cold)

[MrOizo]

Had a electric DC motor fail on a hydraulic pump. There are several ideas floating around.

- One was that the magnets came away from the shell and stuck to the armature while working.
- Another is the wrong grade oil was used for a hotter climate like where i am now in Fiji.

In NZ we use Grade 32
In Aus we use Grade 46
Manufacturers in Denmark use Grade 46.

Would using a Grade 32 in a hotter climate cause more stress on the pump/motor making it work harder?

They way i see it is Grade 32 will be thinner in hotter climates or does the numbering work the other way around?

[MrOizo]

Motor that crapped itself!

[allencr]

I think that viscosity jump is almost insignificant, and if it shortened its life it didn't shorten it by much & was ready to go anyway.
How long was this thing running?
Electric motors burn up all the time, surprised it doesn't happen even more frequently with their high heat & only having that thin varnish as insulation!
DC motor, 12V like a starter motor driven pump on one of those truck's hydraulic tailgate lifts or a big one in a forklift? Those tailgate things have a pretty short duty cycle to keep them from overheating, spec sheet I've got says 66 seconds on 234 off at 500psi & 36 on 264 off at 2000psi.
Can't find the Haldex site for info/specs on yours or something similar, they're on of the biggest manufacturers.

http://www.hfifluidpowerproducts.com/Pa ... Fluid.html

Good luck.
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Also
Those permanent magnets(Ferrite) are glued in & need good contact to dissipate heat.
Yours looks like its gotten water in there, rusted between the housing & magnets, loosening the glue & lifting the magnet causing it to hold in heat & loosen up even more, until it started scraping the armature & really got hot.

[MrOizo]

This is a 3/4hp Leeson 12v DC motor.

The hydraulics lower a pad onto ground & lifts/drops a weight to simulate vehicle loading while measuring deflections. A "Falling Weight Deflectometer"

It runs for about 20-25 seconds at a time and is off for 10-15 seconds.

The pressures are below 1000 psi normally at a max of 800 psi.

[Mr Revhead]

Most hydraulic equipment I have seen here runs 46

[MrOizo]

Most hydraulic equipment I have seen here runs 46

So if you went to the desert would it be advised you run a different oil? If so which way?

I am thinking we should just change to 46 - much more common!

[Mr Revhead]

Ask the manufacturer
My experience is with diggers and loaders etc. For tropical climates the oil was the same, but the cooling system was upgraded

[MrOizo]

Ask the manufacturer

Ha! Will do. Churger burger

[85AW20v]

Talked to one of our electrical maintenance specialists and showed him the photos. He wondered how the stator was fixed to the casing as there weren't any bolt holes visible and if they were glued in some way, then maybe the glue has failed, which could be heat related.

He also suggested checking the bearings as if the bearings are worn then stator/rotor clearances become an issue whcih could result in the damage.

His opinion on the oil grade was it wouldn't make any difference to the motor - it might work harder but that's all. Something other than the oil grade has caused the damage.