Bronze phosphor bearing play ?? Do I need a new one

[gaci]

Can some one tell me if the bronze phosphor bearing has play in the rear end, I know it's a taper, I have it in bits as the oil filler was blocked when I place the shaft inside the bronze phosphor bearing there is play in the end. The big question is do I need a new bearing ???

 

[sunnybob]

bronze taper bearing is a very unusual thing. Are you sure its meant to be?

 

[gaci]

Hi sunny bob, it's on the headstock of the coronet no3 and records cl3/4 lathes.

 

[sunnybob]

is there an adjustable nut to set the pressure? What holds the shaft in?
Never seen a bronze taper bearing inside an engine.

 

[gaci]

Have a look on record power uk for it and you will get an understanding of it and what imakes trying to describe.

 

[Dalboy]

Once you assemble it all back together you will need to adjust the bearing so that it eliminates any movement except for rotatory then oil it and run it for a short period of time then recheck once that is done and adjust once again. After that you should be alright but check it once a week it should not need any more adjustments for a while. The last time I adjusted mine was over 6 months ago but I still check at regular intervals as part of machine check over that I do being an ex plant mechanic it is just a habit.
If you are not sure then go to the record site and download the instruction manual for the CL3, you will need to register. If that fails send me your e mail address by PM and I will send a copy

 

[woodpig]

The manual is available here.

http://www.free-instruction-manuals.com ... 135139.pdf

 

[gaci]

I've got the manual and the know how, I want to know is there play before everything is tightened as sliding the shaft into the bearing where it sits in the taper you are able to wiggle it at the wide end of the bearing. If I had a set of feeler gauges I could tell you how much gap there is probably about a 1mm.

 

[swb58]

If you've had it apart and didn't notice any unusual wear on the shaft then it can be adjusted so that there isn't any play in the shaft. If there's anything irregular about the surface of the bush (bearing) then the shaft will iron it out, you'll have to check it regularly as it will 'wear' quicker than normal until it gets a good fit between shaft and bush.
Having said that, the bush should seat perfectly on the shaft without any wiggle, up to you if you buy a new bush (as long as the shaft is perfect) or refit and keep an eye on it.

 

[sunnybob]

As it is a taper bearing, you cant measure play until it is adjusted to the correct loading. Once there is the correct torque applied to the nut, then you can check for side play.

 

[swb58]

As it is a taper bearing, you cant measure play until it is adjusted to the correct loading. Once there is the correct torque applied to the nut, then you can check for side play.

Sorry, but can't agree there. What we are talking about here is two perfectly aligned components coming together.
Same principle as a morse taper, the bearing should sit on the shaft (or shaft should sit in the bearing) in the same way without the need for any force to be applied. (hammer)

 

[SVB]

No direct experience, but if there is play when tension applied, implies either shaft or bearing bore is elliptical. Can you disassemble and inspect / mic?

S

 

[gaci]

I managed to get a photo of the play while the shaft is seated inside the taper bearing.

 

[sunnybob]

I'm struggling to grasp this. if the bearing is tapered but there is no locking nut, what is holding the shaft in place?

Or is this a morse taper kind of thing where the pressure comes from the piece being machined?

 

[gaci]

Sunnybob http://www.free-instruction-manuals.com ... 135139.pdf down load this and it's on page 29 I think

 

[Jacob]

You can take out the slack by adjusting the lock nuts (one tightened the other loosened) so the taper part is tight and it will run OK but there may still be a gap on the parallel section (which you can see in your photo), which doesn't matter except that oil will tend to run through into the casing. So you either experiment with thicker oil or buy new shaft and bearing.
The gap is due to wear after not having kept the bearing adjusted up tight.
It's a very odd design as all the thrust is taken by the sealed bearing at the other end.

 

[swb58]

I must admit that I've not taken mine apart and it's only now after looking at online images of the shaft that I see that only a part of the bearing is tapered. That's the only surface you need to worry about. As Jacob says a gap between the parallel section is ok as there has to be some degree of clearance. A gap and wiggle in that area as pictured won't have been caused by undue wear.

 

[gaci]

Thank you to everyone I shall put it back together and turn, at least I've saved myself £50, but I won't be telling the wife. Lol

 

[Duncan A]

It's a very odd design as all the thrust is taken by the sealed bearing at the other end.

To avoid confusion here, the sealed bearing is not a thrust bearing; it provides support and alignment for the shaft. The tapered bronze bearing provides a thrust and lateral support bearing surface which is cheap to manufacture, capable of absorbing large forces and runs very smoothly - if adjusted correctly. A very good example of cost effective, simple manufacturing.
The sealed bearing sits in the housing and must allow the shaft to expand/contract axially with temperature changes (it gets quite warm with prolonged use) or there would be serious problems develop with the shaft "trapped" at both ends.

Duncan
EDIT: See below; my comments above are a load of tosh!

 

[Jacob]

It's a very odd design as all the thrust is taken by the sealed bearing at the other end.

To avoid confusion here, the sealed bearing is not a thrust bearing; it provides support and alignment for the shaft. The tapered bronze bearing provides a thrust and lateral support bearing surface which is cheap to manufacture, capable of absorbing large forces and runs very smoothly - if adjusted correctly. A very good example of cost effective, simple manufacturing.
The sealed bearing sits in the housing and must allow the shaft to expand/contract axially with temperature changes (it gets quite warm with prolonged use) or there would be serious problems develop with the shaft "trapped" at both ends.

Duncan

Some confusion here! :lol:
I was confused too when I first looked at it.
The tapered bronze bearing doesn't give thrust support it tapers the wrong way. Any thrust (if you tighten the tail stock frinstance) is taken by the sealed bearing at the other end. That's what I mean about it being an odd design.
The sealed bearing doesn't permit movement - it sits against shoulders - in the housing and on the shaft. The shaft is "trapped" at both ends.

NB this is on a fairly modern CL4 so maybe other models have different design?
This is what mine is like, there is only the sealed bearing (left hand end) to prevent the shaft from being pushed through:

What the tapered bearing does do is allow a lot of wear to be taken up by adjusting the locknuts, which a straight through or top-hat bearing would not. So as long as it holds oil and is frequently adjusted it should have a long life.