Re: [CAD_CAM_EDM_DRO] Digest Number 1871
Posted by
Tony Jeffree
on 2001-12-17 16:00:05 UTC
Very bad idea to rely on the motor for thrust bearings. For a start, on
the ones I have come across so far, there is generally a spring at the back
end of the motor that takes up the end float in the motor shaft, so in one
direction, the maximum thrust the motor can take is no more than the
pre-load on that spring, which isn't very much. In any event, I doubt very
much that the bearings on the motor will be designed to take a significant
axial load. You should assume that handling end thrust is your problem, not
the motor's. Sounds like the leadscrew design you refer to has got it right.
Regards,
Tony
At 23:20 17/12/2001 +0000, you wrote:
the ones I have come across so far, there is generally a spring at the back
end of the motor that takes up the end float in the motor shaft, so in one
direction, the maximum thrust the motor can take is no more than the
pre-load on that spring, which isn't very much. In any event, I doubt very
much that the bearings on the motor will be designed to take a significant
axial load. You should assume that handling end thrust is your problem, not
the motor's. Sounds like the leadscrew design you refer to has got it right.
Regards,
Tony
At 23:20 17/12/2001 +0000, you wrote:
>Just noticed gordonr's leadscrew mount picture in FILES, where the
>end opposite the motor is mounted into thrust bearings. Never thought
>about it before, should I assume it's not good to take the thrust
>through the motor's bearings?