Author Topic: Main gearbox  (Read 1809 times)

0 Members and 1 Guest are viewing this topic.

Offline Peaky 556

Main gearbox
« on: February 05, 2014, 08:14:30 PM »
I'm now looking to make up the gearbox between engines and main generator, and need some fairly chunky ballraces to keep the whole thing together under the onslaught of engine vibrations, and to 'look right'.  The shaft diameter is very probably going to be 10mm, and I quite like the idea of flanged ballraces as it solves one of the problems of location and endfloat.

Technobots' largest offering is this:
http://www.technobotsonline.com/miniature-flange-bearing-mf6700zz-10x15x4.html
which is 10mm bore and 15mm OD.  Does anyone have a source of slightly bigger OD bearings with a flange?
Regards, Tim

Offline Andy B

Re: Main gearbox
« Reply #1 on: February 05, 2014, 08:32:28 PM »
Try Derby Bearings in Siddals Road - very helpful when I've needed bearings for machine tools .
or City Bearings on Ascot Drive.

Andy

Offline IanT

Re: Main gearbox
« Reply #2 on: February 06, 2014, 09:43:01 AM »
Have a look at Arc Euro Trade here (at the bottom) Andy - up to 10x30 (but no flange):

http://www.arceurotrade.co.uk/Catalogue/Bearings/Ball-Bearings/Ball-Bearings---Metric/Ball-Bearings---Metric-6mm-to-10mm-Bore

Regards,

IanT
Nothing's ever Easy - At least the first time around.

Offline Peaky 556

Re: Main gearbox
« Reply #3 on: February 07, 2014, 11:33:14 PM »
I see that ArcEuro do a very large range of small ballraces, but not flanged.  Thanks Ian.
Regret not had time to shop in Derby Andy, but have discovered a seller on ebay of many types of flanged bearings:
http://www.ebay.co.uk/itm/350892494807?var=620169811216&ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649#ht_2129wt
Half of the battle is knowing what diameter combinations are available and this guy sells a large range.  I may just buy a sample of the 10x22x6 for a general impression of quality, whether sealed or shielded, stainless or chrome steel etc.  At £3.29 for four delivered it won't break the bank!
The smaller ones may be good for axle bearings?
Thanks, Tim

Offline Peaky 556

Re: Main gearbox
« Reply #4 on: February 10, 2014, 01:00:48 PM »
We have possibly done ArcEuroTrade a disservice here as a closer look at their listings suggests that some are flanged, if they have the 'F' prefix.  These would appear to be in 6, 8 and 10mm bore, the latter being 10x19x7 at £2.57 each.
I'm still waiting for the cheapo ones from ebay, so no comments yet.
Cheers, Tim

Offline Peaky 556

Re: Main gearbox
« Reply #5 on: March 21, 2014, 12:02:25 AM »
Cheapo Chinese bearings have arrived and they seem very good. They are a tightish sliding fit on an off-the-shelf piece of ground silver steel bar.
Tonight I undertook some test machining of bores in a piece of scrap 1/4" alloy plate using a slot drill, and (on the ones that didn't chatter) the result was a fairly close clearance fit to the outer races. A larger slot drill made the recess for the flange, and the ball race was snug without tightness.
Fortuitously a tight fit is needed on the rotating shafts and a clearance is needed on the O/D, in the interests of permitting relative sliding for thermal expansion growth and avoiding fretting on the shaft. In another application where the o/d is rotating and the shaft stationary the opposite would be needed in terms of fit. Bearings pressed into both sides of a wheel and running on a fixed shaft for example.