Author Topic: 1934 gearbox  (Read 241 times)

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Offline saluki42

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1934 gearbox
« on: 11 Feb 2021 at 11:03 »
Hi there I've looking at starting the rebuild of my gearbox and have a query around bearings somebody may be able to help with. The smaller bearing are all still available from normal suppliers the query I have concerns the sleeve gear bearing. Looking at the body casting there are a couple of cast in bronze inserts one acting as a shaft support bush and one as the housing for a standard bearing race and the larger section houses the sleeve gear. The bearing to the best of my knowledge consists of two rows of rollers possibly 1/4" diameter contacting the sleeve gear body itself and a expect running in a hardened steel outer race which is a press pit into the bronze insert in the casting.
If this is the case has anybody got any idea at all of a part number for the outer race, the dimensions of this race ( i'll have to get one made if the worse comes to the worse) or even better got a spare they would be willing to part with for the right inducement.

Regards and fingers crossed
Chris

Offline Doug

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Re: 1934 gearbox
« Reply #1 on: 11 Feb 2021 at 16:04 »
Chris,

Yes, two rows separated by a thin hardened washer of 1/4 dia. x 1/4 long rollers; should be 38 of them. I suspect the outer race is not a standard race at all, but made for the job. With luck, it might not be worn enough to worry about renewing. Options are try and find oversized rollers so you can lap the journal and hone the race. Lacking that, lap the journal, fit standard size rollers, and get a bespoke race made undersized to compensate. You might be able to find a outer race for a off the shelf cylindrical roller bearing which would need minimal alterations, but I do not know the size of the Douglas race to use as a starting point.

-Doug



[fix typo.  11Fev21  Doug]
« Last Edit: 11 Feb 2021 at 17:15 by Doug »

Offline saluki42

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Re: 1934 gearbox
« Reply #2 on: 11 Feb 2021 at 16:49 »
As always thanks for the help Doug but unfortunately I don't have any parts of this bearing so I think it will be try to see if either a standard race can be modified or see if I can get one made specially. At present the gap between the shaft and the inner bore is much to big to go any other way.

Thanks Again
Chris

Offline saluki42

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Re: 1934 gearbox
« Reply #3 on: 14 Feb 2021 at 11:11 »
Latest up date, inner race of a cylindrical - IR45X52X40 Inner Ring    IR45X52X40   1   8.48 - this will need the bronze cast insert being opened up by 0.35mm and the internal diameter of the race honed out to accept the 1/4 x 1/4 rolleres and hopefully problem solved.

Chris


 

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