one way needle bearing 1

[subsearobot]

I am looking at a one-way needle bearing (mcmaster 6392K44 ) for a a double shafted motor. motor will be reversed to drive a pump mounted on either end of the shaft. when reversed, I do not want to drive a pump in reverse...

how is torque transmitted? does not seem like I want to interference-fit the shaft into the needles, so I do not see how locking can occur.

am i misunderstanding its application?

mcmaster 6392K44

thanks

 

[MikeHalloran]

McMaster is using incorrect terminology. ... probably by intent, just to deal with the Great Unwashed.

The device does not have an ABEC rating for precision or for radial load, because it's NOT a bearing.

What it is, is a roller clutch, supplied in a drawn shell.
The shell looks similar to the shell supplied with a needle roller bearing, and may in fact be identical except for markings.

The clutch elements are NOT needle rollers. They are not round. They are shaped and arranged so as to jam between the shell and a hardened shaft when the shaft rotates in one direction, and to slide on the shaft with little friction when the shaft rotates in the other direction.

Note that you cannot use it as a bearing; radial location must be provided by an adjacent bearing. I think some manufacturers offer the combination as a unit, but it's not all that common.

Note also that common motor shafts are relatively soft, and may be permanently deformed by a roller clutch, probably enough to interfere with the freewheeling.

McMaster is a great source for stuff that you need in small quantities right away, but in this case you need to sit down with a bearing manufacturer's bearing catalog and a bearing manufacturer's roller clutch catalog, and go through all the fine print.



Mike Halloran
Pembroke Pines, FL, USA

 

[subsearobot]

thanks mike.

 

[GregLocock]

The main use for a proper bearing with a one way action is for uphill conveyor belts, which would otherwise unload themselves at great speed in the event of a transmission failure. However I have forgotten their official name, one way bearing is not it.


Here's one way of doing it

http://www.marland.com/products/sprag/sprag-csk.html

Cheers

Greg Locock


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