Combined Linear + Rotary Motion

Unique design allows simultaneous linear travel along the shaft axis and rotation around the shaft axis — a capability not available in standard linear ball bearings.

3-Row Ball Circuit

Three ball rows distributed around the circumference support radial loads in all directions during both linear and rotary motion simultaneously.

Nickle-Plated Option

All ST models can be supplied with nickel plating for enhanced corrosion resistance in humid or mildly corrosive environments.

Defined Maximum Stroke

Each model has a rated maximum stroke (listed in the specification table). The stroke must not be exceeded to prevent ball circuit overrun.

GCr15 Chrome Steel

Through-hardened to HRC 58–64 for both linear and rotary wear resistance. Surface ground to Ra 0.4 µm on shaft-contact surfaces.

15 Bore Sizes

Available from 6 mm to 100 mm bore, covering the full range of industrial shaft diameters requiring combined motion guidance.

Cam-Follower Mechanisms

ST bearings enable the combined linear extension and rotational indexing motion required in cam-driven assembly machines and rotary transfer systems.

Spring-Return Actuators

Pneumatic and mechanical spring-return actuators often require the actuator rod to rotate during retraction to reset a detent or cam — the ST series accommodates this without a separate rotary joint.

Precision Adjusters

Fine-adjustment screws and micrometer-head mechanisms in optical and metrology equipment use stroke bearings to provide smooth combined linear and rotary positioning.

Pick-and-Place Heads

Rotary-linear pick-and-place heads in SMT assembly machines use ST series bearings to combine vertical linear travel with rotational part orientation in a single axis.

🔎 Shaft Specification

Ground to h6/h7 tolerance, HRC 60+ hardness, Ra 0.4 µm. Both the cylindrical surface quality and hardness affect rotary motion performance as well as linear travel.

🔧 Stroke Limit Compliance

Programme the motion controller to stay within the maximum stroke listed in the specification table. Mechanical hard stops should be set 2–3 mm inside the rated stroke limit as a safety margin.

📈 Lubrication

NLGI-2 grease for both linear and rotary modes. Re-lubricate every 300 km of combined linear travel (more frequently than standard linear bearings due to the additional rotary wear component).

⚙ Housing Alignment

Ensure the housing bore is aligned with the shaft within 0.02 mm/100 mm. Misalignment introduces side loading that is particularly damaging in combined-motion bearings where the ball tracks must accommodate two motion directions.

①

Identify Application Type

Confirm that combined linear and rotary motion is genuinely required. If only linear motion is needed, the LM...UU series provides higher load ratings for the same bore.

②

Select Bore & Model

Match bore to shaft nominal diameter. Verify maximum stroke requirement against the specification table.

③

Verify Load & Life

Calculate L10 using C and equivalent radial load P. If insufficient, upgrade to ST...B heavy duty series for the same bore.

④

Contact Us

MOQ 100 units. Contact our team with engineering drawings specifying bore, housing, load case, stroke, and target life.

📞 Ready to Order?

MOQ is 100 units per model. Provide engineering drawings with bore, housing bore tolerance, load case, stroke, speed, and target service life. All catalogue data is for reference only.