- This topic has 17 replies, 10 voices, and was last updated 13 years, 6 months ago by
.
-
Posts
-
Hi guys. I’m after some opinions. These days I seem to be seeing more and more early bearing failure on machines. I mostly work on the Indesit/HP stuff and I am aware of people dislike for the welded tanks however Iv just been thinking of what’s the reason behind early failure of the bearings is
I have a few ideas, obviously cheap bearings plays a part however I’m not convinced its the total reason, iv also been thinking about the way the seal meets the support. On the old HP WM there was a brass collar on the shaft that the seal was sealing on. As this was brass it would not rust, on the newer stuff this is gone and the seal goes directly onto the stainless shaft. I often seen these badly rusted, this must be part of the reason as the seal fails then water gets in.
As I said I don’t know what Bosch or the other makes do, is there still brass ?
Just pondering really.
Re: Premature Bearing Failure
Im constantly seeing newer machines everyday with bearing failure,The indesit/hpt welded plastic tubs seem to go after a cccouple of years i havn’t cut one open but if the seal is the same as the ones fitted to the hpt wma range iwould have thought these seals would leak from the first day the machine was used it doesn’t even seem to be a proper seal at least not like alot of other makers use its not a face seal like the old servis ones as theres no front half to the seal and they don’t work like an oil seal because theres no inner lip so it beats me how it works at all.
Re: Premature Bearing Failure
It’s all to do with BALANCE……….
Any shaft driven device, be it a ships propellor, a jets fan blade or even a flailing blade on a Flymo mower, has to be ‘balanced’. In each of the three examples above, they are balanced in relation to the motor shaft and its supporting bearings. Each are designed to run at high speed so it is essential they remain balanced and not chipped, bent or distorted in any way. Otherwise the straining forces of excessive vibration to the drive shaft and bearings will quickly result in early dramatic failure.
With your modern washing machine the drum is lightweight and is subjected to centrifugal forces that, when spinning at high speed, are sufficient to apply excessive transmitted stress throughout its drive chain. This puts enormous strain directly on the bearings, especially the front bearing that’s usually the first in line for failure. Add to that the heat generated coupled with the electrostatic charges generated compounds the problem further.
Manufacturers are fully aware of the design weaknesses and skilfully apply them to ensure their product has, what they consider, a reasonable service life nevertheless.
Re: Premature Bearing Failure
Who cares I mean really beyond either the people who made them (who have to pay a penalty to the brands for any premature failure) or the brands who have to claim from the peeps who made them.
You’ve probably seen 0.00000000000000000000000000000000000000001{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of what is made fail prematurely.
Re: Premature Bearing Failure
My thoughts are that the appliance manufacturers have increased the load capacity & spin speed without putting in signicantly larger bearings.
Overdosing of detergent using low temp’ washes & shorter wash times with only one rinse which doesn’t get rid of all the soapy water will lead to the seals going hard, cracking & leaking.
Once a few drops of water ingress in past seal, the rust begins.Re: Premature Bearing Failure
Not sure if larger bearings help. 6207 seems to be a particularly common failure in Lux and Hotpoint even when the speeds were only 1000. Although that wasn’t always “premature.”
Mike.Re: Premature Bearing Failure
I have noticed that the majority of failures I get use liquid detergent. Had Anyone else noticed this.
Sent from Steves
iPhone using TapatalkRe: Premature Bearing Failure
I always thought that the seal fails first allowing water to hit the inner bearing accelerating the bearing failure, if the bearing didnt get wet it wouldnt wear out.
Sent from my iPhone
http://www.kitchenkitsw.comRe: Premature Bearing Failure
Premature drum failures are often sludgy, slimy, mouldy, so liquid detergent, low temperature washes and too much fabric conditioner seem to be factors. I too suspect it is the quality of the seal, rather than the quality of the bearings, that the the major factor in premature bearing failure.
Re: Premature Bearing Failure
Iv been doing some research on seals. Iv found that on rotating shaft seals lip friction is the big issue. Depending on type of seal and lubrication life will vary vastly.
Looking into it manufactures seem to use different types. Some are oil seals designed to hold oil in, some of these have dust lips as well, others are liquid to liquid seals designed to separate two different liquids apart, the are also grease seals as well.
Interestingly the info made a point of the requirement to lubricate the seal lip where it meets the shaft, if there is a lack of lubrication or it dries up it carbonises and the seal over heats and fails. It also stated that the shaft has to be polished after manufacture to remove screw. When it made with a lathe there will be a natural screw in the direction of the way it was cut. If this it towards the seal contaminants will be pushed towards the seal and build up at its face as it rotates. Again causing failure.
I’m convinced the bearing failure is to do with seal failure as well. When changing them on the Hotpoint WMA with the stainless steel spider that shaft is always badly corroded, that must the cut into the seal and it will pass water. The quality of the stainless steel used has to have an impact.
I’m convinced that if the brass insert was what the seal met they would last longer.
Also lubrication of the seal may be an impact.
Re: Premature Bearing Failure
madangler1 wrote: The quality of the stainless steel used has to have an impact.
Since when have they been using stainless steel?
Re: Premature Bearing Failure
Maybe time to use the same bearings used in the aero industry.
“Yes madam washing machines are now £2,0000 ish minimum, due to the quality of the bearings used, it’ll never fail beyond 1 million hours of use”.
Customer walks away wishing appliances were as cheap as the back in 2010 stating your “talking the p8888, I’ll go somewhere else”
Re: Premature Bearing Failure
The WMA seals (both 35mm and 30mm types) are different. This was pointed out to us by Phidom a couple of years back. They have an inner part which revolves inside an outer part. (It’s very stiff to move when new so you wouldn’t know about it. Maybe it moves more easily once it gets going.) The part that makes contact with the shaft isn’t supposed to revolve against the shaft.
Thus you can put a bit of debor on the (cleaned and degreased) part of the shaft that contacts the seal and it shouldn’t matter about the pitting caused by corrosion. If you grease the seal you’ll be over-riding the intended function and inviting early failure.
Mike.Re: Premature Bearing Failure
Well reading that seems to reasure my thoughts about these seals being so useless anything which is going to spin inside a metal casing needs lubrication.
These seals must start breaking down after about the first spin ,whenever ive replaced these ive always put a good big dollop of water proof grease behind the seal when fitting it, and have to say have had good results bearings have lasted a few years or more.But at least we could get inside these tubs and have a go not like the stuff being produced now with bearings constantly going after 12 – 18 months then the machine just goes to the scrap yard its eventually going to make us all redundant unless we can upsell to people so they buy a machine that can be repaired.Re: Premature Bearing Failure
larry wrote: anything which is going to spin inside a metal casing needs lubrication.
Sorry, I didn’t make that clear enough. They are greased at the interface between inner and outer seal – they’re greased there during production. You don’t touch any of that when you’re fitting them, it’s all tucked away out of sight. If you have a look at one of these seals next time you use one you’ll see what I mean. You can turn the inner part in relation to the outer part.
What I was saying was that greasing the interface between the shaft and the seal is probably counter productive as you’re creating a tendency for things to move at a point where they were (I think) intended to stay still.
As to putting grease behind the seal in the space between it and the bearing I can’t say I’ve ever tried it but I do remember reading in Graham Dixon’s book, IIRC, about not overdoing the grease – though I think that was in relation to taper rollers.I sometimes wonder whether the bleed hole is a good idea or not. Zanussi don’t use one. It obviously allows water to get away but not fast enough. I think they should make another one at the top so the air can get in and the water out. Would need to prevent water getting in the motor obviously.
Mike.
- You must be logged in to reply to this topic.