Pressing "blind" Bearings- Order Of Operation

[wildo]

I need to reassemble the spindle pulley on my drill press. I'm a little confused about the order of operations when pressing bearings into "blind" positions.

Let me explain:

• If you are pressing a bearing into a housing (like a car hub and wheel bearing) I know that you'd want to make sure to push on the outside race since that is coming into contact with the hub.
• Similarly, if you are pressing a bearing onto a shaft, I know that you'd want to push on the inside race since that is coming into contact with the shaft.
• You never push on the race that isn't coming into contact with the surface your installing the bearing into.

...Easy enough.

But for my spindle pulley, the bearing is pressed onto a shaft molded into the pulley, and also pressed into a housing on the drill press head itself:


Now, when I took the drill press apart, the service manual stated to drive the pulley off by striking the bearings from inside the head. This caused the pulley to come off with the bearings intake. I wonder if this would imply that I should press the bearings onto the shaft of the pulley, and then press the assembly into the housing in the drill press head?

I'm new to this stuff. If there is some reference (Machinist's Handbook?) that defines the proper order of operations for this kind of assembly- I'd like to know about it. Any advice would be appreciated.

 

[Kernbigo]

put it in to your bottom item first then into the pulley next

 

[Billh50]

If the bearing is pressed onto the pulley shaft then press it onto that first. Then use a hair dryer or heat gun and heat the spindle housing so that the bearing drops into the housing.
That is how spindle repair shops do it. I was in the same building with a spindle repair shop and have watched them do that every single day. It may take a a half hour or so to get the housing up to temp to expand enough for the bearing. Let it sit after installing the bearing into the housing so it will cool off and shrink back to size.

 

[Billh50]

To replace the starter gear on harley clutch baskets we put them in the oven at 250 degrees F for about 1/2 hr. They drop right onto the hub then and when cooled they shrink tight enough to turn the big motors over no problem. SO I guess if you can put the spindle housing in the oven you can do that too,

 

[Kernbigo]

use a infrared light bulb that is what i used when i rebuilt spindles

 

[wildo]

Good info, folks! I didn't consider heating the housing. This makes complete sense rather than bending the bearings trying to press them in. At least I was thinking straight! So quick follow up- does it matter if the housing is cast iron? The housing that the bearings drop into is the head of the drill press itself. I'm assuming that as long as the heat is consistently distributed and gradual, then it'll be a nonissue, yes?

 

[Billh50]

Should not make a difference if it is cast iron. Just try to heat it evenly.

 

[wildo]

Should not make a difference if it is cast iron. Just try to heat it evenly.

Actually- no, I am not sure of that. I'm not sure how to tell the difference either.

 

[Billh50]

you should be ok either way as long as you heat it up as even as possible.

 

[wildo]

Billh50- just because I'm a sponge right now for info, is this what people use a spark test for? How would you know if it's steel [what did you call it before you edited? Hard cast steel?] or cast iron?