ball screws Design FeaTures
IntroductionRepair Services Design FeaturesSelection GuideBrochure
Raceway Profiles
RBC Linear Precision Products uses the Gothic as well as the round raceway
profile as standard designs.
Round Profile
- Smooth
running
- Optimal
stiffness
- Optimal
life
- Minimum
friction
- Minimum
wear
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Gothic
Profile
- Smooth
running
- Minimum
friction
- Minimum
wear
- Negligible
axial
play Preloading Systems
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Preloading Systems
Backlash, Preload
and Stiffness
Ball bearing screws possess a certain amount of inherent axial freedom
and play, or backlash.
If the load is always
maintained in one direction, backlash is not an application criterion
because the balls will always be held to one side of the ball raceway.
In applications where a reversing load is present, coupled with positioning
accuracy requirements, it is recommended that a suitable RBC Linear
Precision Products preloaded ball bearing screw be specified.
Ball Nut Packages
RBC Linear Precision Products ball screw assemblies are available
in a variety of ball nut packages designed to meet your specific needs.
Depending on the series ball screw assembly you select, you may be able
to choose from single nut packages with two or four ball circuits, or
a flange-to-flange, or single flange double nut package. Each ball nut
package has its own set of unique features which provide specific benefits
over another design. Which type you eventually select will depend on
the specific load, life and mounting requirements of your application.
Ball Return Systems
A ball return system
is necessary to ensure the continuous circulation of the balls. RBC
Linear Precision Products uses two different systems:
Internal
Ball Return |
External
Ball Return |
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After
each turn, the balls are fed back to the preceding turn by a specially
designed and patented floating liner situated inside the nut. |
After several
turns the balls are fed back to the leading end of the circuit through
a tube which is mounted outside the nut. |
Integral
Preload |
Double
Nut Preload |
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|
With the
integral preload system, one circuit of balls is loaded against
the other circuit of balls to provide a tension preload. This is
achieved by placing a slight shift in the lead between the two circuits. |
With the
double nut preload method, a thin spacer is usually inserted between
two nuts. When the two nuts are then drawn together, a compressive
preload results. |
Single
nut, two circuit |
Double
nut,
flange-to-flange preload |
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Single
nut, 4-circuit |
Double
nut,
single flange, 4-circuit |
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