The application below
requires both a dead weight of 200 pounds ( pulley assembly mounted on
top of the linear slide where the greater part of the load is creating a
Mx roll moment) which wants to lift
one side off the shafting while the other is driven into the shafting.
The linear slide system also has to
be exceptionally clean ( low-to-no debris ) and must be
self lubricating - no lubricants.
In this initial concept drawing, the pulley wheel rotates clockwise
creating a moment load along the My axis (pitch) while also creating a
moment load along the Mz (yaw) axis. The pulley has a moment arm of 7
inches and creates a roll moment. Not to mention the column load being
generated. The valve/port seal is well to the side of the slide and
weighs approximately 75 pounds.
To mitigate these over-turning
moments, we chose to use 3 Open Minuteman Self Lubricating linear
bearing pillow blocks on each side. The shafting was 1" diameter 300
series stainless. By using 3 single, open pillow blocks, we were able to
keep the slide from edge loading and binding.