Understanding Bearing Dimensions

[freebo86]

So with the current COVID situation, store visits being limited and hard to see and touch things in person before buying. I have a question in regards to Press-In Flange Bearing.

These 3/4 Press In Flange Bearings have the following characteristic.
Inner Bearing I.D. (in.) 3/4 in.
Outer Bearing I.D.(in.) 1-3/8 in.
Inner Spindle O.D. (in) .75 in.
Outer Spindle O.D. (in) 1.4 in.

What I want to do with these, is attach the bearing to a step Pulley end which has a 3/4" Hole through it which I would use 3/4" round rod as my "axle" if you will. My question in regards to the below linked bearings, the flange end on these based on the dimensions and you guys' knowledge would it allow me to press the bearing flange end into the 3/4" bore hole on the pulley and then stick the round rod through this assembly?

I don't see how I can press these into the bore hold and still maintain a 3/4" hole in order to slide the rod through? Or am I miss understanding something? The O.D dimensions are of no concern.


https://www.princessauto.com/en/detail/2-pc-3-4-in-press-in-flange-bearings/A-p8066920e

 

[Firebrick43]

First these bearings are absolute **** for belt pulleys. The are designed for low speed hand cart wheels and such.

Second you can’t press a hole, ie inner diameter (ID) into a hole???.

The outer diameter(OD) of a bearing is the dimension of a counter bore for it to be pressed into. You are not going to find a bearing with a 3/4 OD and have a meaningful ID. So you need to either counterbore the pulley for a bearing on a lathe or fix the shaft to the pulley and place the bearings on what ever your mounting to.

Is this for a reduction on a drill press?

 

[freebo86]

First these bearings are absolute **** for belt pulleys. The are designed for low speed hand cart wheels and such.

Second you can’t press a hole, ie inner diameter (ID) into a hole???.

The outer diameter(OD) of a bearing is the dimension of a counter bore for it to be pressed into. You are not going to find a bearing with a 3/4 OD and have a meaningful ID. So you need to either counterbore the pulley for a bearing on a lathe or fix the shaft to the pulley and place the bearings on what ever your mounting to.

Is this for a reduction on a drill press?

Thanks! Yes my other option was to go your second route, which is possible just I stumbled on these flange bearings and figured I ask.

So what is the dimension of that flange on these bearings? If it’s 3/4” realistically it would fit? I understand now that it’s not the right bearing for this application.

And yes it is for a drill press speed reducing pulley. Good guess! I wish I had access to a lathe to counterbore the pulley.

To clarify, I don’t need a OD of 3/4 as I realize a bearing with 3/4 may not even exist. It is the ID I am curious about.


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[The Cobbler]

maybe you can snap a couple of pictures to explain what you re trying to do.

 

[BillK]

free,
If you go to the McMaster Carr web site you can search bearings and find what you need. They have product drawings for everything on the site. MSC is the same way.

 

[freebo86]

free,
If you go to the McMaster Carr web site you can search bearings and find what you need. They have product drawings for everything on the site. MSC is the same way.

See images. The bearing that’s on there now is just a reference. Something I had kicking around. But basically my idea was to take the flange bearing (linked above) and place as I have the one shown in the picture but press the flange into the pulley bore. Then slide the 3/4s rod through the entire assembly. This allows the pulley to spin as mentioned above.

maybe you can snap a couple of pictures to explain what you re trying to do.

No go, McMaster does not ship to Canada. Plus I can find bearings locally.


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[matt_i]

There's a bearing designation which has a groove machined into the outer race for a snap ring. You press it until it hits that "flange". I forgot what that is for the moment....

As Firebrick stated above, the "electric motor grade" bearings are going to be far above that linked bearing in quality and longevity. Something like a 620x is a bearing I'm talking about...but it doesn't have the groove. I have to look that up....

x = 3,4,5,6,7,8,9 all different sizes.

 

[Robbie B]

There's a bearing designation which has a groove machined into the outer race for a snap ring. You press it until it hits that "flange". I forgot what that is for the moment....

As Firebrick stated above, the "electric motor grade" bearings are going to be far above that linked bearing in quality and longevity. Something like a 620x is a bearing I'm talking about...but it doesn't have the groove. I have to look that up....

x = 3,4,5,6,7,8,9 all different sizes.

I think it’s either and NJ or a JEM bearing designation your talking about for the snap ring. We use those at work on the smaller pumps we run.


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[SGKent]

my layman's eyes tell me you don't have enough meat on that pulley at the smallest step to bore a hole to hold a bearing. Maybe you might get away with an Oilite (or brass sleeve if you add some kind of fitting on it to keep it lubed.)

This kind of sleeve:

 

[Innovate1]

The ball bearings 6xxx are normally installed with a press fit. Without it the bearing is likely to spin on the shaft and wear it down over time - I have seen it happen more than once. Without a lathe I don't see how you are going to make a long lasting assembly with those style bearings. I would mount the pulley on a shaft and bearings for the shaft. Look at decent quality pillow block bearings. As I recall they have set screws for the shafting. So you should be able to use off the shelf parts and end up with a good assembly.

 

[freebo86]

my layman's eyes tell me you don't have enough meat on that pulley at the smallest step to bore a hole to hold a bearing. Maybe you might get away with an Oilite (or brass sleeve if you add some kind of fitting on it to keep it lubed.)

You are correct, boring out a larger hole on the pulley is not an option. 1) due to not enough meat on pulley 2) I simply do not have a lathe to do such task.

The ball bearings 6xxx are normally installed with a press fit. Without it the bearing is likely to spin on the shaft and wear it down over time - I have seen it happen more than once. Without a lathe I don't see how you are going to make a long lasting assembly with those style bearings. I would mount the pulley on a shaft and bearings for the shaft. Look at decent quality pillow block bearings. As I recall they have set screws for the shafting. So you should be able to use off the shelf parts and end up with a good assembly.

This is basically the end result I am going after.

 

[Innovate1]

The ball bearings 6xxx are normally installed with a press fit. Without it the bearing is likely to spin on the shaft and wear it down over time - I have seen it happen more than once. Without a lathe I don't see how you are going to make a long lasting assembly with those style bearings. I would mount the pulley on a shaft and bearings for the shaft. Look at decent quality pillow block bearings. As I recall they have set screws for the shafting. So you should be able to use off the shelf parts and end up with a good assembly.

Just want to clarify that my comments about making a long lasting assembly with "those style bearings" was referring to the 6xxx style since I realized it may not be clear which I meant. As others pointed out the original ones you posted are very low quality and intended for low speed. Maybe fine for the wheel of a cart but not for a spindle.

 

[rsanter]

Best you can hope for with that design is to use needle/roller bearings on a smaller shaft.

Otherwise you need to change the design so that the shaft stays fixed in the pullies and the pulley and shaft rotate together in bearings placed in the arm

 

[metlmunchr]

For the sorts of loads and speeds you'd have on this, the PV values for oilite bronze bushings would do the job.

Use flanged bushings, 5/8 id x 3/4 od x 1 1/8" long. Use setscrew shaft collars to position the pulley on the shaft with some clearance such that the bushings flanges aren't riding on the collars in operation. Use 5/8 ground shafting for the spindle. It will provide the proper running clearance with the bushings.

All the above available from MSC for around $30.