Page 12 - Parker - Daedal manually driven positioning slides and stages

Manual Manual Linear Positioners/Stage Overview
Positioners

Ball Bearing Positioners Crossed Roller Positioners
Pages 61-88 Pages 89-114
Parker Daedal ball bearing positioners combine a ball Parker Daedal crossed roller positioners combine a crossed
slide with a drive mechanism. The ball slide is spring roller slide with a drive mechanism. The crossed roller slide
loaded against the drive mechanism to is spring loaded against the drive mechanism
provide a constant preload to provide a constant
between the drive preload between the
and the slide. drive and the slide.
These positioners These positioners
are available with are available with a
a number of different drive mechanisms including fine number of different
adjustment screw, differential screw, imperial and metric drive mechanisms including fine adjustment screw,
micrometer heads, and digital micrometer heads. differential screw, imperial and metric micrometer heads,
and digital micrometer heads.
The ball and rod bearings on the ball bearing positioners
consist of two rows of hardened steel balls, each preloaded The crossed roller bearing system is composed of two
between four hardened ground steel rods. This design rows of rollers. Each roller is alternately crossed at 90° with
provides ultra-smooth, extremely low-friction motion by the next and captured in “V” grooves, located on the base
reducing the contact area between the balls and the ways and top. Since rollers provide a larger (line) contact surface
Additionally this design provides extremely good straight than ball bearings, a crossed roller positioner has higher
line and flatness accuracy. All Parker Daedal ball bearing load carrying capability than a ball bearing positioner of
slide positioners incorporate 440C hardened stainless steel comparable size. These changes also significantly increase
ball and rods to ensure corrosion resistance and long life. the stiffness by increasing the contact area of each bearing.
Crossed roller positioners are preloaded to eliminate any
Both the top and base aluminum mounting surfaces are side play and to provide a uniform coefficient of friction.
precision machined to ensure flatness. Most models are
available in both imperial and metric mounting configurations. Crossed roller positioners are constructed of corrosion-
resistant black anodized aluminum and high carbon steel.
Members are precision machined to assure flatness and
parallelism for both top and bottom mounting surfaces.
Crossed roller positioners are available in imperial and
metric mounting configurations depending on model
Functional Comparison selection.
Straightness/
Smoothness Friction Flatness Accuracy Load Capacity
Ball Bearing Positioner Exceptional Extremely Low Very Good Moderate
Crossed Roller Positioner Very Good Very Low Very Good High

www.parkermotion.com Parker Hannifin Corporation
Electromechanical Automation Division
0 Irwin, Pennsylvania