Author Topic: Bearings vs. Bushings?  (Read 27313 times)

0 Members and 1 Guest are viewing this topic.

Offline JohnBotTopic starter

  • Jr. Member
  • **
  • Posts: 14
  • Helpful? 0
Bearings vs. Bushings?
« on: April 03, 2010, 01:36:11 PM »
ok, stupid question: can someone tell me the difference between bearings and bushings. I've actually trued to google it, and can't find a straight forward answer, other than the obvious (i.e. ball bearings have balls, etc).

Also, if you can give me an example of a practical use for each, that would be great.

Thanks.

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Bearings vs. Bushings?
« Reply #1 on: April 03, 2010, 03:41:21 PM »
Hi,

A bushing is really just "a hole" in a material that (should) have features making it suited for the purpose (like eg. the lower friction of sintered material with lubricant).

A bearing use some means (like balls, needles/rollers or whatever), to counter the friction that you have with an axle running in a bushing.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline amando96

  • Robot Overlord
  • ****
  • Posts: 187
  • Helpful? 1
Re: Bearings vs. Bushings?
« Reply #2 on: April 03, 2010, 05:01:42 PM »
Basically what he said, here's a pic:


Left is bushing, right is bearing  :)
Rorcle, 60% complete
AATV, 5% complete

Offline JohnBotTopic starter

  • Jr. Member
  • **
  • Posts: 14
  • Helpful? 0
Re: Bearings vs. Bushings?
« Reply #3 on: April 09, 2010, 01:02:17 PM »
thanks for the pics and info.

So, ok, let's say I have a bearing just like that. A ring ball bearing. And I want to mount it to something and have an axle run through it. How do I mount the bearing? I know that I can buy flange or pillowblock bearings that includes the mounting hardware. What if I just have the bearing itself? Any creative ideas on how to mount it in something?

For example, if I have a bearing with an Outside Diamter of 1/4 inch, I guess I could cut a 1/4 inch hole in a piece of wood or somethinn and stick it in. But that seems like there could be alignment problems.


Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Bearings vs. Bushings?
« Reply #4 on: April 09, 2010, 02:55:28 PM »
Hi,

What if I just have the bearing itself? Any creative ideas on how to mount it in something?

For example, if I have a bearing with an Outside Diamter of 1/4 inch, I guess I could cut a 1/4 inch hole in a piece of wood or somethinn and stick it in. But that seems like there could be alignment problems.
I don't see why there should be more alignment problems than if you used a pillow block (at least not initially), as both types would need carefull alignment.

For a 1/4" bearing (that's quite small, something you pulled from a HD?) I guess the easiest would be to drill a 1/4" hole in a piece of aluminum of a thickness like the width of the bearing and mount a circular shim or thin plate with a smaller hole on each side to hold it in place.

You could mount it in plastic or wood of course, but the smaller the bearing the harder it will probably be to get a good fit and alignment.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


Get Your Ad Here