Jun 3, 2026
Products
High Speed and a Long Service Life: A Wheel Guide for Transfer Systems
For production lines that make food, drugs, and cosmetics and for equipment used to manufacture batteries, where the same processes are repeated endlessly to produce a high volume of products, reducing cycle times is key for boosting productivity. As a result, linear motors with high-speed drive are increasingly being utilized for transfer systems over conventional belt-driven or chain-driven devices. In this article, we’ll introduce the Curvilinear Wheel Guide (Model CWG), which offers smooth, high-speed travel along both straight and curved tracks.
Intended Applications and Anticipated Challenges
As previously mentioned, the food, drug, and cosmetics industries and battery manufacturing equipment face a need for higher productivity. On top of that, depending on the product, the manufacturing process also has to be able to handle variable-mix, variable-volume production. While linear motor-based systems excel at unidirectional transfers, when the path is a straight line, linear motors have to execute reverse operations, and individual movers cannot move past each other. That's why, for food, drug, and cosmetics production and battery manufacturing equipment, guide components are often arranged in oval and square tracks.
These types of configurations allow devices to keep traveling in the same direction, which enables high-speed drive and eliminates the need for transfer tables to go in reverse, resulting in reduced cycle times. However, while guides are expected to move smoothly and at high speeds, earlier THK products were not able to meet those requirements in systems with curved tracks.
Service life has also presented a challenge. Conventional linear transfer systems often use resin wheels, which wear down easily and require maintenance. These wheels also have a limited load capacity, which restricts their utility.
The Curvilinear Wheel Guide for Transfer Systems
To overcome the challenges that come with linear transfer systems, THK developed the Curvilinear Wheel Guide (Model CWG). Whether the track is shaped like an oval or a square, the Curvilinear Wheel Guide can move at speeds up to 5 m/s, and its steel wheels grant it an extended service life and make it very easy to maintain. Thus, it solves both the high-speed compatibility and service life problems that have accompanied linear transfer systems.
Curvilinear Wheel Guide rails can be combined in any arrangement, including in oval and square tracks. This freely configurable system is also designed to be used in combination with pick and place robots that assist with transferring products between processes.
Structure of the Curvilinear Wheel Guide
The Curvilinear Wheel Guide is primarily made up of carriage plates, wheels, and rails (straight and curved). Sets of concentric wheels and eccentric wheels are attached to the carriages on either side of the rails, facilitating smooth travel along the track.
Two types of carriages are available for the Curvilinear Wheel Guide: a fixed-curvature type and a multi-curvature type. The fixed-curvature type has the wheels directly attached to the carriage plate, which makes the carriage height shorter. Because the relative positions of the wheels are fixed, this type can be used in configurations where straight rails are used with curved rails of the same radius that are arranged so that they all bend in the same direction, such as in an oval or square track.
The multi-curvature type, however, features rotor units attached to the underside of the carriage plate that combine a cross-roller ring with concentric and eccentric wheels. The two rotor units follow the shape of the rail track, so this type can even be used when curved rails have different radii or bend in different directions.
Features of the Curvilinear Wheel Guide
The Curvilinear Wheel Guide boasts the following features.
Design Freedom
You can combine straight and curved rails to make shapes such as ovals or squares, or any other track you require.
Optimized for High-Speed Drive
The carriage can be driven at high speeds up to 5 m/s. Whether the rails are lined up straight or combined with compatible curved rails, the carriage can glide over them all with speed.
Easy Carriage Installation from Above
A wrench can be used to rotate the eccentric wheels to adjust the amount of clearance. This makes it easy to install carriages or remove them from pre-assembled rail tracks from above.
As mentioned previously, Curvilinear Wheel Guide carriages can travel smoothly over both straight and curved rails, so work can be performed at various points along the rails. Additionally, because carriages can be removed from above, you can replace them without having to take out any rails, even if they’re arranged in a closed loop like an oval or a square. This way, you can freely adjust the number of carriages depending on the payload or operating conditions.
Optimized for Transferring Light Loads at High Speeds
The Curvilinear Wheel Guide offers the freedom to travel over straight and curved paths and the flexibility to add, replace, or remove carriages as needed. If you are a food, drug, cosmetics, or battery manufacturer and you’ve been struggling with transferring light loads at high speeds and reducing cycle times, please reach out to THK.
* This content is based on information that was released in Japanese on June 3, 2026.