Cooling Fan Internals

Billy1mate · 24th July 2012, 17:13

Does anyone have a photo of the inside of the lid of a cooling fan? I ask because mine looks like some sort of phosphor bronze bush and some sort of felt pad although this has mostly disappeared allowing the 'bush' to rattle in the pressed steel housing.

T-Cut · 24th July 2012, 20:53

I interpret the 'inside lid of the fan' to be the motor casing end plate which houses the shaft bearings. These are phosphor bronze and I'd guess the felt pad is the lubricating pad. The bearings shouldn't rattle because they are held under tension with an annular spring. It sounds like you should be thinking about a replacement fan system. Are you attempting to fix the motor brushes?

TC.

Arctic · 24th July 2012, 23:47

Quote:

Originally Posted by Billy1mate

Does anyone have a photo of the inside of the lid of a cooling fan? I ask because mine looks like some sort of phosphor bronze bush and some sort of felt pad although this has mostly disappeared allowing the 'bush' to rattle in the pressed steel housing.

Hi Ade
below you will find what mine looked like before i chnaged it for a two speed fan with gold resistor

Arctic

Billy1mate · 16th August 2012, 12:32

Quote:

Originally Posted by T-Cut

I interpret the 'inside lid of the fan' to be the motor casing end plate which houses the shaft bearings. These are phosphor bronze and I'd guess the felt pad is the lubricating pad. The bearings shouldn't rattle because they are held under tension with an annular spring. It sounds like you should be thinking about a replacement fan system. Are you attempting to fix the motor brushes?

TC.

That's what I meant, yes. The brushes have been replaced and the fan was run on the bench before fitment, without checking the pcb & relays. The fan when spun by hand is a bit notchy/stiff but does have free spots where it moves nicely. Thing is, is this the new brushes on the commutator not bedded in or the phosphor bronze bearing in the lid? Incidentally now the fan is back in the car it doesn't work off the air con panel, so it seems the pcb/relays maybe the problem. It's going for a T4 session tomorrow. Watch this space, might need a new fan, hope not.

Billy1mate · 16th August 2012, 12:35

Arctic, my fan internals were black but not disintegrated like yours.

COLVERT · 16th August 2012, 12:54

Quote:

Originally Posted by Billy1mate

That's what I meant, yes. The brushes have been replaced and the fan was run on the bench before fitment, without checking the pcb & relays. The fan when spun by hand is a bit notchy/stiff but does have free spots where it moves nicely. Thing is, is this the new brushes on the commutator not bedded in or the phosphor bronze bearing in the lid? Incidentally now the fan is back in the car it doesn't work off the air con panel, so it seems the pcb/relays maybe the problem. It's going for a T4 session tomorrow. Watch this space, might need a new fan, hope not.

The phosphor bronze bearing in the lid is a sintered bearing. It is porous to allow oil to pass through it. Maybe it has dried out. The pad next to it must be oiled before re-assembly which is maybe why it is not running freely.

If there is too much movement ( loose bearing in its housing. ) then the armature might touch the field coils and cause friction there.

Colvert.

SD1too · 16th August 2012, 13:23

Quote:

Originally Posted by Billy1mate

The fan when spun by hand is a bit notchy/stiff but does have free spots where it moves nicely.

What you've described here sounds normal. I think you might be worrying unnecessarily about the bearing. When I re-brushed my motor I didn't do anything to the bearing, and I've had no trouble since.

Quote:

... is this the new brushes on the commutator not bedded in ...

I can't see how that would result in "notchy/stiff with free spots". Did your new brushes have a concave contact surface to match the commutator by the way?

Quote:

... now the fan is back in the car it doesn't work off the air con panel, so it seems the pcb/relays maybe the problem ... might need a new fan, hope not.

Replacement PCBs are available from Jules. Relays are available too. Absolutely no need to buy a new fan. You said that it ran satisfactorily on the bench, so the motor must be o.k. I doubt that the T4 will pinpoint the fault; it will just say that the slow/medium/fast speed is inoperative which you know already.

Keep us posted. I recently helped another member diagnose a PCB fault. His fan would never stop running!

Simon.

Billy1mate · 18th August 2012, 16:06

Does anyone know the lane 'Wits End'? Well I am at the end of it, threaders to use navy slang. PCB & relays replaced with, told 'good ones, fully working'. Yep no fan, no air con, same as before. There must be a wiring fault between air con panel & fan/air con compressor. Completely stuck now.
T4 session did as SD1 said & confirmed no fan but I'd hoped the relays & pcb would have sorted it. Going for a beer I've had enough of this pile of tat.

T-Cut · 18th August 2012, 17:51

Quote:

Originally Posted by Billy1mate

Going for a beer I've had enough of this pile of tat.

You don't mean that really do you.

Are you sure there's enough gas in the aircon system to actually allow it to operate? No gas, no fan, no nothing.

TC

Billy1mate · 18th August 2012, 20:03

New condensor, system leak checked, regassed & functionally tested. I think I have 2 problems because the aircon doesn't flash up full stop. It should run up without the fan, then switch off if the fan doesn't run up. Snags continue.

24th July 2012, 17:13	#1
Billy1mate Posted a thing or two 120d M Sport Join Date: Feb 2012 Location: Sunny Weymouth Posts: 1,815 Thanks: 153 Thanked 142 Times in 121 Posts	Cooling Fan Internals Does anyone have a photo of the inside of the lid of a cooling fan? I ask because mine looks like some sort of phosphor bronze bush and some sort of felt pad although this has mostly disappeared allowing the 'bush' to rattle in the pressed steel housing.

24th July 2012, 20:53	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	I interpret the 'inside lid of the fan' to be the motor casing end plate which houses the shaft bearings. These are phosphor bronze and I'd guess the felt pad is the lubricating pad. The bearings shouldn't rattle because they are held under tension with an annular spring. It sounds like you should be thinking about a replacement fan system. Are you attempting to fix the motor brushes? TC.

16th August 2012, 12:35	#5
Billy1mate Posted a thing or two 120d M Sport Join Date: Feb 2012 Location: Sunny Weymouth Posts: 1,815 Thanks: 153 Thanked 142 Times in 121 Posts	Arctic, my fan internals were black but not disintegrated like yours.

18th August 2012, 16:06	#8
Billy1mate Posted a thing or two 120d M Sport Join Date: Feb 2012 Location: Sunny Weymouth Posts: 1,815 Thanks: 153 Thanked 142 Times in 121 Posts	Does anyone know the lane 'Wits End'? Well I am at the end of it, threaders to use navy slang. PCB & relays replaced with, told 'good ones, fully working'. Yep no fan, no air con, same as before. There must be a wiring fault between air con panel & fan/air con compressor. Completely stuck now. T4 session did as SD1 said & confirmed no fan but I'd hoped the relays & pcb would have sorted it. Going for a beer I've had enough of this pile of tat.

18th August 2012, 20:03	#10
Billy1mate Posted a thing or two 120d M Sport Join Date: Feb 2012 Location: Sunny Weymouth Posts: 1,815 Thanks: 153 Thanked 142 Times in 121 Posts	New condensor, system leak checked, regassed & functionally tested. I think I have 2 problems because the aircon doesn't flash up full stop. It should run up without the fan, then switch off if the fan doesn't run up. Snags continue.