Cleaning Clutches ?

[fishleg]

Stupid question but we see alot of refurbs and most of the time we clean them out with some alcohol which is great... What I was wondering is how they actually work I understand they magnetise and grip but I've had them to bits and don't fully understand how they work could someone kindly explain what happens when they energise ? Inside there just seems to be a metal plate and a circular ring that grips that plate on a shaft.

The plate seems extremely smooth to the eye so again makes me wonder how it actually grips...

Thanks for any help.
Fishy

[mtech]

It is an electromagnet. When the coil is energized it becomes a magnet that grabs the other disc and pulls the two surfaces together. One is being driven and the other is not. When the coil gets energized the two surfaces stick together and this transfers the drive to the shaft that does the work. Hope that helps!

[Stirton.M]

ooops...took too long to put in an answer...

what mtech said....and

The clutch of a automobile manual transmission operates in a very similar manner, with the exception that in that case, a very strong spring pushes the pressure plate against the clutch plate.

[fishleg]

Since its a magnet i guess the smoother the 2 surfaces the better they will grip. As some times when you open them up you can see a ring thats been grounded out.

[blackcat4866]

All correct. There were techs back in the old days that thought rougher was better. They would sand the plate surfaces. Well magnetism doesn't work that way. The more contact area the better. That means the plates need to be as smooth as possible for the most magnetic "grip". These same techs would also oil these clutches. Then they were guaranteed to slip. All it takes is one misinformed tech to make every clutch on your machine slip in less than 1/2 hour. =^..^=

[Rudi]

All correct. There were techs back in the old days that thought rougher was better. They would sand the plate surfaces. Well magnetism doesn't work that way. The more contact area the better. That means the plates need to be as smooth as possible for the most magnetic "grip". These same techs would also oil these clutches. Then they were guaranteed to slip. All it takes is one misinformed tech to make every clutch on your machine slip in less than 1/2 hour. =^..^=

Please help me to educate these techs or get rid of them in a nice way because they are nice guys but they did me so wrong on a DI 3510 syncro clutch today ,its a sealed unit and i could just not CLEAN HIS OIL OUT. Maybe i should speak to the hardware supplies so that they can tell them the product is discontiniued .

[fishleg]

Thanks for the help guys actually makes sense . Rare that you need to go that far but sometimes when your not sure you definitely don't wanna make it worse so thanks to this bit of info it will definitely help.

Another myth for you guys maybe you can shed some light on it... some of our engineers believe filing the shafts a bit on a one way bearing helps it grip faster. I'm one of these it does make sense but just wondering if you guys have seen it help or disagree completely.

As you can tell I have a lot to learn still quite new to the business but am eager to learn all these little secrets but more so understand them.

[ZOOTECH]

"Another myth for you guys maybe you can shed some light on it... some of our engineers believe filing the shafts a bit on a one way bearing helps it grip faster. I'm one of these it does make sense but just wondering if you guys have seen it help or disagree completely."


Not sure about filing, but a fine grit sandpaper (nothing lower than 240) keeps the one way from slipping.

[blackcat4866]

Anything that reduces the size of the shaft makes it grip more poorly. Typically these shafts are made of some crappy white metal with a hard chrome plating. They are fine until the chrome plating starts to chip. The chips get caught up in the one way bearings, and the white metal shreds quickly. The best thing that you can do for a one way bearing is to soak it out in alcohol, examine the shaft and wipe it down with the alcohol, then with the lightest oil that you have place three drops inside the one way gear and re-assemble. If the shaft is trashed sometimes you can shim the one-way gear to one side or the other, so it's gripping some undamaged shaft. That can buy you a few days until the new parts arrive.

If it's still slipping, you'll need to replace the one-way bearing/gear, and the shaft if possible. Occasionally those shafts are riveted into a frame, and not readily replicable.

As sanding shafts goes, I don't believe that it helps. Knurling the shaft may help because it effectively restores some of the lost diameter, but I've never been equipped for that situation. =^..^=

[Stirton.M]

Please help me to educate these techs or get rid of them in a nice way because they are nice guys but they did me so wrong on a DI 3510 syncro clutch today ,its a sealed unit and i could just not CLEAN HIS OIL OUT. Maybe i should speak to the hardware supplies so that they can tell them the product is discontiniued .

Use lots of methanol to deal with the oil issue. Takes a bit of doing, but it will flush most of the oil, along with dirt debris, out. And when you have the chance, steal the oil out of the other techs cases.

I've been in the habit of chasing after the other techs who insist on oiling things and making a point to them to not use oil anywhere except in a bearing. My issue is simply that if they use oil to get rid of a squeaking bushing or idler roller, the squeak will be gone for a while, but will come back with a vengeance when the oil has attracted more dust. It is best to take a few minutes to remove the part, clean the bushing and shaft, or replace if they are heavily worn, than to simply leave it for other techs, like me, to fix later.

[Stirton.M]

As sanding shafts goes, I don't believe that it helps. Knurling the shaft may help because it effectively restores some of the lost diameter, but I've never been equipped for that situation. =^..^=

I agree. Sand paper or filing is a bit extreme on the torrington bushings. Like you, I use methanol to clean the bushing and the shaft. If the shaft looks polished from the bushing, I will use a scotch pad to scuff the surface to remove that shine, it barely does more than this to the shaft. In most cases, I simply just replace the torrington with a new one, usually when I replace the feed/pickup tires related to the bushing.