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Collection, Preservation and Display of Old Lawn Mowers

Qualcast cylinder blade bearings: Modern equivalent?

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Greetings

I am in the process of rebuilding my Qualcast Punch Auto 35. I would like to replace the current Cone + Cup bearing which look like they could still function OK, however seeing as I have it completely striped apart I'd rather get new bearings for my blade if possible.

Please advise what bearing number would be most suitable and would I need to do any mods to get it to fit properly?

Internet picture of the bearing holder + Bearing cup + Cone:

Exploded view:

From what I can gather, a modern bearing would replace the following components : 401, 405, 406, 415, 416, 814, 815, 816

I imagine such a bearing as below would be a candidate? However, I think I'd need some sort of spacer/spring/key to ensure the bearing stays where they need to be on the shaft and to stay loaded?

Thank you

PS. NB! I am located in South Africa. eBay or any other online options which supply OEM/after market parts is a no-go due to shipping cost.

olcadmin Thu, 28/01/2021

I'd be inclined to try and replace like for like. By the look of the first photo the bearings are standard ball bearings (a standard engineering item) pressed into the square housing (which will be a part made by or for Qualcast for the specific mower). They should, in theory, be easy and inexpensive to replace.

I would expect it should be possible to extract the bearing from the housing with care using a suitable drift, punch, or screwdriver to gently tap it out. Once you have it out you should find some numbers on the bearing which will identify its type and size. If not you should be able to measure the dimensions which can then be matched to replacements offered by suppliers.

A quick search found the following supplier in South Africa and their prices look about the same as I have paid in the UK fairly recently.

https://www.africabearings.com/

Once you have the old bearings and part number and/or the dimensions they should be able to help. Or just send them one of the old ones for them to identify. When you have the replacements you will need to carefully put them into the original square housing.

I did some marketing work for SKF many years ago and they claimed to be able to supply a replacement for any bearing they had ever made and equivalents for the majority of competitors' main lines (as it happens my 100 year old Atco has some SKF bearings on its cutting cyclinder).

I don't think the bearing in the photo at the bottom is what you need. It's a tapered roller type and designed for completely different applications.  

toRRa Thu, 28/01/2021

Thanks for that bit of info :)
 

The problem I am running into is not the bearing itself (ie. the balls), but rather the cones.

This mower uses these two cones, and I can find them anywhere in SA.

wristpin Thu, 28/01/2021

That bearing system, and in particular the cones, was specific to Suffolk and Qualcast and they won’t be found as an off the shelf bearing .

The shaft is approximately 5/8” so finding a taper thrust bearing with an inner to fit won’t be an issue but the outer may be, and may need some machining of the housing. On the other hand you might get lucky after carefully removing the pressed in steel inner cup.

The UK bearing supplier, Simply Bearings, has a good website that allows you to enter dimensions and a few minutes spent perusing that site may be time well spent,  but I imagine that SA has something similar.

Unfortunately your images are somewhat distorted and it is difficult to view the running surfaces  but they don’t look too bad . Don’t worry about the rough finish to the end of the short cone, that is quite normal, even on new ones.

toRRa Fri, 29/01/2021

Those pictures of the bearings are ebay photos (ie. not mine).

Both my bearing cones look like the short one with the rough top edge.

 

I would have thought a modern cup/cone bearing would be able to replace an  "old" cup/cone bearing.

Looks like I'll have to take a trip to my local bearing engineering shop and have a chat with them and hope i speak to someone competent.

olcadmin Fri, 29/01/2021

My mistake, sorry.

As wristpin says, the cones were specific parts for the mower. However, the parts were quite common so - although postage from UK might be annoying - it should be possible for someone to supply them to you. There's also the possibility that someone can make new cones for you on a lathe - I am sure it's simple enough for someone with the right kit.

hortimech Fri, 29/01/2021

You could use taper roller bearings if you can find any to fit, but a problem would be setting the pre-load, I don't think a 'spring' would be enough, There would also be the problem of the bearing housings moving whilst setting the cut.

I wonder if the bearings from the 17" Suffolk Super Punch (the alloy one) would fit ?

By the way, what Qualcast called the Punch in your country is called an EP Panther in the UK.