Starter sprag clutch specifications

karlburroughs

Joined
Feb 20, 2024
Messages
4
Country flag
Hi,
Looking at running a sealed bearing sprag clutch, rather than the standard (wet, oiled) sprag bearing. Does anyone know the max torque specification for the standard sprag, or what I should aim for please?
Thank you.
 
Cool!
Have you found a supplier for a sealed version of the sprag?

Glen
 
karlburroughs said:
Hi,
Looking at running a sealed bearing sprag clutch, rather than the standard (wet, oiled) sprag bearing. Does anyone know the max torque specification for the standard sprag, or what I should aim for please?
Thank you.
Click to expand...
I have an Alton starter running in a dry belt drive primary
Alton told me there is no need for lubricant on the sprag
 
worntorn said:
Cool!
Have you found a supplier for a sealed version of the sprag?

Glen
Click to expand...
Not really. Most bearing stockists list sealed sprag clutch/freewheel bearings.
But to achieve the same torque capacity they are much larger than the Norton bearing. For instance there is a 40*80*22 sprag bearing with a rating of 325Nm. Or a 35*62*20 rated at 175Nm (224Nm standard bearing).
I am trying to drive a belt drive clutch drum with a second belt, but struggling for space to fit such a freewheel bearing, etc. Work in progress!
 
baz said:
I have an Alton starter running in a dry belt drive primary
Alton told me there is no need for lubricant on the sprag
Click to expand...
that seems counter intuitive. most bearings last longer if lubricated, is there not a possibility of it sticking in the engaged position due to no lubrication. just thinking out loud Baz
 
Tripler said:
that seems counter intuitive. most bearings last longer if lubricated, is there not a possibility of it sticking in the engaged position due to no lubrication. just thinking out loud Baz
Click to expand...
I agree
Even though I was told by Alton no lubricant was needed I give it a squirt of oil every couple of months or so
 
It's an all metal clutch, when freewheeling there is no load, when engaged you have loads but only movement during the short engagement time. Air Conditioning clutches are metal to metal and run dry, the problem with dry running is rust as they are out in the open.
 
You must log in or register to reply here.
Back
Top