Ball screws and assemblies
Ball Screw Assemblies
Precision ball screw drives for converting rotary motion to controlled linear movement -- category engineering reference, selection guidance, support-bearing relationships and discovery pathways.
What ball screws and assemblies do
A ball screw assembly pairs a precision screw with a ball nut so rotary input produces accurate linear travel. Rolling elements recirculate between screw and nut, reducing friction compared with acme (trapezoidal) lead screws and supporting higher efficiency, repeatability and duty cycles.
Ball screw drives are used where controlled linear positioning is required from a rotary motor or handwheel input -- for example CNC machine axes, industrial automation, medical equipment and aerospace mechanisms.
System design must consider axial load, speed, stiffness, backlash control, lubrication and support bearing arrangement at both screw ends. This page is a category authority surface; it is not a manufacturer-specific catalogue.
Ball-screw technology overview
Engineering theme
Screw and ball nut
The nut houses recirculating balls that roll along precision-formed raceways on the screw, converting rotation to linear displacement.
Engineering theme
Rolling vs sliding
Ball screws use rolling contact; acme lead screws rely on sliding contact. GBC content cites lower friction and higher efficiency for ball screws in precision duty.
Engineering theme
Precision class
Lead accuracy, preload and manufacturing grade affect positioning repeatability in machine tools and measuring equipment.
Engineering theme
Drive train integration
Motors, couplings, support bearings and linear guides form a complete axis. Ratings and stiffness must be evaluated for the full assembly.
Ball screws vs related linear-motion technologies
| Ball screw vs acme lead screw | Ball screws use rolling elements for lower friction and higher efficiency in precision, high-duty positioning axes. Acme screws suit simpler, lower-speed sliding-contact applications. |
|---|---|
| Ball screw vs profile rail guideway | Ball screws convert rotary input to linear travel along a screw axis. Profile rail guideways constrain a carriage along a rail for linear guidance. Machine tool axes often use both: screws for drive, guideways for load support and alignment. |
| Ball screw vs LM linear bushing | LM bushings run on hardened shafts for economical linear guidance. Ball screws provide driven positioning along a defined lead. Selection depends on whether the axis must be motor-driven with defined lead accuracy. |
| Ball screw vs ball spline | Ball splines transmit torque while allowing axial slide on a splined shaft. Ball screws address driven linear positioning without transmitting shaft torque through the nut. |
Selection considerations
Engineering theme
Load and duty
Dynamic and static load ratings, acceleration profiles and shock must be evaluated for the full drive train, not the screw alone.
Engineering theme
Speed
Rotational speed interacts with screw diameter, length and support stiffness. Lubrication and thermal limits must be confirmed with manufacturer data.
Engineering theme
Lead and accuracy
Lead accuracy and manufacturing grade govern positioning repeatability. Preload influences backlash and stiffness.
Engineering theme
Stroke
Travel length affects screw slenderness, critical speed and the need for intermediate supports on long axes.
Engineering theme
End support
Fixed and floating support bearings carry axial and moment loads. See the ball screw support bearing reference for angular-contact arrangements.
Engineering theme
Lubrication
Grease or oil selection depends on speed, environment and maintenance interval. Match lubricant to nut and bearing suppliers where specified.
Support-bearing relationship
Ball screw support bearings are angular-contact bearings at the fixed and floating ends of the screw. They absorb axial loads, control system stiffness and accommodate thermal elongation of the screw.
GBC content on the NSK RHP Ball Screw Support Bearings page references fixed-end preloaded pairs, floating-end expansion allowance, and NSK literature series BSN, BSF, WBK and TAC. Support bearing selection must be evaluated together with the ball screw nut preload, speed and lubrication.
| Screw end | Engineering role ( summary) |
|---|---|
| Fixed (drive) end | Typically uses a preloaded angular-contact bearing pair to carry axial loads and maximise stiffness toward the nut. |
| Floating (support) end | Allows axial thermal expansion while maintaining radial guidance; defined with the fixed end as a system. |
This relationship is engineering context only. NSK RHP support bearing information does not imply that Golden Bearing Company supplies NSK ball screws or bearings unless separately confirmed.
Selection inputs for engineering review
When requesting ball screw assembly support, define the parameters below. Model-level lead, diameter and load tables require manufacturer catalogue verification.
| Selection input | Engineering relevance |
|---|---|
| Stroke / travel length | Defines screw length, critical speed considerations and support spacing. |
| Speed and duty cycle | Affects heat generation, lubrication method and bearing/screw life evaluation. |
| Lead and lead accuracy | Lead accuracy, preload and manufacturing grade affect positioning repeatability in machine tools and measuring equipment. |
| Axial and moment loads | Dynamic and static ratings must be evaluated for the full drive train, not the screw alone. |
| Backlash control | Nut preload and manufacturing grade influence positioning repeatability and stiffness. |
| Support arrangement | Fixed and floating end bearings carry axial and moment loads; angular-contact arrangements are typical. |
| Lubrication | Grease or oil selection depends on speed, environment and maintenance interval. |
| Environment | Contamination, coolant exposure and maintenance access affect sealing and service life. |
GBC discovery and market-reference pathways
Manufacturer-specific ball screw catalogues are not reproduced on this category page. discovery pathways on Golden Bearing Company:
| Pathway | GBC reference |
|---|---|
| Ball screw support bearings | NSK RHP engineering reference for fixed/floating angular-contact support (BSN, BSF, WBK, TAC series context). |
| Linear motion guideways | Profile rail systems often paired with ball screw drives on machine tool and automation axes. |
| Super-precision bearings | Spindle and high-speed rotary bearing context adjacent to precision screw drives. |
| Linear motion type authority | Broader linear motion configurations, selection factors and category FAQ. |
Market-reference manufacturers cited in existing GBC content (industry literature only; no supply claim):
| Market-reference name | note |
|---|---|
| Ewellix | Appears in industry literature for ball screw products. Not a GBC catalogue on this page. |
| Thomson | Appears in industry literature for ball screw products. Not a GBC catalogue on this page. |
Typical applications
GBC content associates ball screw assemblies with:
- CNC machining centres and lathe axes
- Industrial robotics and pick-and-place systems
- Medical imaging and laboratory automation
- Aerospace actuation and test rigs
- Packaging, printing and semiconductor handling
- Presses and process equipment requiring controlled linear force
Application notes are engineering guidance only and do not guarantee suitability without manufacturer verification.
Catalogue and commercial boundary
Golden Bearing Company does not publish model-level lead, diameter or load tables on this page without manufacturer verification. Manufacturers such as Ewellix and Thomson appear in industry literature for ball screw products; listing them is market-reference only and does not imply distribution, authorization or stocking. Share axis duty, stroke, speed and accuracy requirement for engineering quotation.
Common questions
A ball screw is a precision mechanical drive that pairs a threaded screw with a ball nut. Recirculating balls roll between screw and nut raceways, converting rotary input into accurate linear travel with lower friction than acme lead screws.
A ball screw assembly is the complete drive unit: precision screw, ball nut, and typically the end support bearings, motor coupling and mounting interfaces that define axis stiffness and alignment.
Rotation of the screw (or nut, depending on design) causes balls to roll along precision raceways. The nut travels axially along the screw by a distance defined by the lead per revolution.
Lead is the linear distance the nut travels per one revolution of the screw. Lead accuracy and manufacturing grade affect positioning repeatability. Numerical lead values require manufacturer catalogue data.
Define stroke, speed, axial and moment loads, lead accuracy requirement, preload/backlash needs, support arrangement, lubrication and environment. Evaluate the full drive train including support bearings and guides, not the screw in isolation.
Lead accuracy, manufacturing grade, nut preload, mounting stiffness and thermal stability all influence positioning repeatability. GBC content cites precision class, preload and manufacturing grade as primary factors.
Load, speed, duty cycle, lubrication, contamination, alignment and support bearing condition all influence service life. Dynamic and static load ratings must be taken from manufacturer catalogues; this page does not publish life calculation inputs.
Preload reduces backlash and increases stiffness by eliminating internal clearance in the nut assembly. Excessive preload raises friction and heat at high speed. Preload must be matched to the application and manufacturer guidance.
Screw ends must be supported to carry axial loads, define system stiffness and control thermal expansion. Angular-contact bearings in fixed and floating arrangements are typical. See the ball screw support bearing reference page for detail.
The fixed end uses a preloaded angular-contact pair to maximise axial stiffness. The floating end allows the screw to expand thermally while maintaining radial guidance.
Send stroke, speed, axial load, lead accuracy requirement, duty cycle, mounting arrangement (fixed/floating), environment and any known designation. Manufacturer catalogue data is required for final sizing.
Ball screws provide driven linear positioning; profile rail guideways constrain and support the moving element along a rail. Machine tool and automation axes often combine both technologies.
Grease or oil depends on speed, temperature and maintenance interval. Lubricant selection should be coordinated with ball nut and support bearing requirements where specified by the manufacturer.
Whenever lead, diameter, load ratings, speed limits, critical speed, accuracy grades or life calculations are required for design sign-off. This category page provides selection context only.
Request an Engineering Quote
Share shaft bore, speed, torque duty and ordering designation for Ball Screw Assemblies. Send axis duty, stroke, speed, lead accuracy requirement, axial load and support arrangement for ball screw assembly engineering quotation.