Rising labor and material costs are pushing manufacturers to maximize productivity. At the same time, limited factory floor space has made compact equipment design a top priority to better utilize production areas.

Rising labor and material costs are pushing manufacturers to maximize productivity. At the same time, limited factory floor space has made compact equipment design a top priority to better utilize production areas.

Design and construction of ball splines

To meet the growing demand for lightweight and compact components, THK has introduced a new lineup of compact ball spline models: LT-X, LF-X, and LTR-V, incorporating some of the most advanced technologies available today. Let’s take a closer look at the key features and technologies behind these products.

Left: LF-X model; Right: LT-X model

Model LTR-V

1. Compact design and reduced weight

By redesigning the shaft diameter, these ball splines have a noticeably smaller external profile compared to conventional models. This reduces the overall size by up to 20%, making it much easier to design more compact machines.

Comparison between the conventional model and the LT-X model

In particular, the rotating ball spline model LTR-V, which features an integrated support bearing, is up to 46% lighter than previous generations thanks to the use of the LT-X ball spline unit. Reduced weight also means lower moment of inertia, allowing the system to start up and stop more quickly.

Conventional model vs. LTR-V model

2. Smooth motion and high-speed performance

These ball splines employ an optimized ball circulation path, enabling smoother ball movement and reliable performance at high speeds. Testing has confirmed continuous operation over 10,000 km without any abnormalities.

Compared with previous models, the new series delivers significantly smoother motion with much lower fluctuation in sliding resistance.

High-speed durability test conditions:

Sliding resistance test conditions:

Test result charts

3. A wide product lineup

In addition to the LT-X, LF-X, and LTR-V models, the compact ball spline series also includes the LFK-X and LFH-X, offering customers even more lightweight and space-saving options.

Left: LFK-X model; Right: LFH-X model

The LFK-X and LFH-X models have a lower overall height than the LF-X, allowing for cleaner installation and easier layout of surrounding components. The square flange of the LFK-X and the cut flange of the LFH-X also contribute to lighter weight compared to the round-flange LF-X model.

Standard model

Weight comparison of the LF-X, LFK-X, and LFH-X models

4. Reduced maintenance frequency

These ball splines are compatible with the optional QZ Lubricator. This lubrication unit can be installed at either end of the ball spline and supplies an optimal amount of lubricant from its built-in reservoir directly to the raceways on the spline shaft.

By continuously replenishing lubricant, the QZ Lubricator maintains a stable oil film between the balls and the raceways, significantly extending lubrication maintenance intervals. Because it delivers only the required amount of lubricant, the system is also environmentally friendly, minimizing grease dispersion into surrounding areas.

Structure of the QZ Lubricator

Case study: Real-world applications of compact ball splines

Case study 1

An industrial robot manufacturer aiming to reduce robot weight selected the LF-X model for the robot arm’s sliding mechanism. As a result, overall weight was reduced by 20%. The lighter design lowered inertia, enabling higher operating speeds, faster acceleration and deceleration, and reduced energy consumption thanks to the lower load on the drive motor.

Case study 2

In semiconductor manufacturing equipment that requires extremely high positioning accuracy, the compact LT-X model combined with the QZ Lubricator allowed the system to operate for a much longer period before lubrication maintenance was needed.

In addition, these compact ball splines are widely used in space-saving transfer equipment, providing smooth linear motion as well as in many other industrial applications.

As the official distributor of THK products in Vietnam, Temas offers not only a full product portfolio—from linear motion guides, ball screws, linear stages, cross roller guides to electric actuators—but also comprehensive solution support for customers.

If you are looking to select the most suitable THK ball spline for your application, Temas is ready to assist with analysis and propose the optimal solution for your requirements. Contact us today for expert consultation.