High Torque Caged Ball Spline

THK's cage technology, which is the culmination of its technologies and know-how, has been applied to ball splines.
The use of a ball cage maintains the aligned circulating motion and enables high-speed operation.
The cage prevents balls from impacting each other and causing mutual friction, enabling low noise and low dust generation. They also allow for long-term maintenance-free operation by improving grease retention.
The torsional rigidity of the nut is ensured through a high-torque structure. Shaft rigidity is also improved by approximating the form of the spline shaft to a circular shape.

Precautions on Use

Types

Highlight feature tags

Long-term maintenance free
High torque type
Cylindrical type
Solid spline shaft
Hollow spline shaft

Splineshaftdiameter(mm) : 25,30,40,50,60,70,80,100

Long-term maintenance free
High torque type
Flanged type
Solid spline shaft
Hollow spline shaft

Splineshaftdiameter(mm) : 25,30,40,50,60,70,80,100

Features

Structure and features

The caged-ball technology, developed by bringing together THK’s technologies and know-how, is now integrated in the new Ball Spline.
The integration of the ball cage enables the circulating motion of evenly spaced balls and high-speed response to be achieved.
It eliminates collision and mutual friction between balls, and realizes low noise, pleasant running sound and low particle generation. As the grease retention is increased, long-term maintenance-free operation is also achieved.
The high-torque design provides the nut with excellent torsional rigidity. The spline shaft also has enhanced rigidity, thanks to its rounded design.

High-speed Response

Models SLS/SLF adopt the caged-ball technology to enable the circulating motion of evenly spaced balls to be maintained and high-speed response to be achieved, the cycle time of the machine can be improved.

[Conditions]

Model tested	SLS50
Testing environment	22 to 27.5℃
Stroke	1000mm
Maximum speed	200m/min
Acceleration/deceleration	5G(49m/s²)
Applied load	Light preload(CL)
Lubricant	THK AFB-LF Grease

[Test results] No anomaly after travelling 10,000 km

Improvement on the spline shaft’s rigidity

Redesigning the shape of the conventional high torque type spline shaft to be more circular significantly improves its torsion and flexural rigidity.

Unit: mm

Nominal shaft diameter 25	LBS	SLS
Minor diameter ø d	19.5	21.6
Major diameter ø D₀	24.5	25.0
Ball center-to-center diameter ø dp	25	25.2

Low Noise, Pleasant Running Sound and Low Particle Generation

Models SLS/SLF adopt the caged-ball technology, they eliminate collision and mutual friction between balls, and realize low noise, pleasant running sound and low particle generation.

[Conditions]

Model tested	SLF50/LBF50
Stroke	600mm
Speeds	30,50,100,150m/min
Measuring instrument	Noise level meter

Overview of the test machine

[Conditions]

Model tested	SLF50CL+350LP/ LBS50CL+350LP
Maximum speed	30m/min
Acceleration	2.84m/s²
Stroke	200mm
Amount of air supplied	1L/200s
Lubricant	THK AFE-CA Grease
Equipment using the product	Particle counter

Appearance of the test machine

Long-term Maintenance-free Operation

Models SLS/SLF adopt the caged-ball technology to substantially increase the grease retention, thus achieving long-term maintenance-free operation.

Smooth Motion (Small Rolling Fluctuation)

Models SLS/SLF adopt the caged-ball technology and a new circulation method, thus achieving stable and smooth motion with small rolling fluctuation.

[Conditions]


Model tested	SLF50
Speed	10 mm/sec
Applied load	Medium preload(CM)
Lubricant	THK AFB-LF Grease

Types of Spline Shafts

Precision Solid Spline Shaft (Standard Type)

The spline shaft is cold-drawn and its raceway is precision ground. It is used in combination with a spline nut.

Special Spline Shaft

THK manufactures a spline shaft with thicker ends or thicker middle area through special processing at your request.

Hollow Spline Shaft (Type K)

A drawn, hollow spline shaft is available for requirements such as piping, wiring, air-vent and weight reduction.

Housing Inner-diameter Tolerance

When fitting the spline nut to the housing, transition fit is normally recommended. If the accuracy of the Ball Spline does not need to be very high, clearance fitting is also acceptable.

Table1 Housing Inner-diameter Tolerance

Housing Inner-diameter Tolerance	General conditions	H7
Housing Inner-diameter Tolerance	When clearance needs to be small	J6