24 Jul 2024


Linear guide keeps its rollers caged

Linear guide keeps its rollers caged

THK has developed a linear guide which it claims is the first to use caged rollers. It says that this design delivers many advantages including high rigidity, high load ratings, and smooth movement

“It will knock the competition for six,” predicts THK`s Mark Kendle.

The large contact area of roller bearings allows the guide to carry heavier loads than systems based on ball bearings. The rollers have a 45 degree contact angle, providing equal loading in each direction, and allowing the guide to be mounted in any orientation.

But the usual drawback with rollers is that they do not circulate well. They tend to lift as they recirculate, leading to vibration. “It`s the last thing you want for accurate machining,” says Kendle. The caged construction of the THK Super Roller Guide (SRG) is said to eliminate this problem.

Another claimed advantage of the new guide is that its rolling resistance is half that of conventional products, even at low speeds. In addition, it uses small rollers to create a greater contact area, thus enhancing radial stiffness.

THK hopes that the guide will help it to capture a large slice of the world market for machine tools that use roller bearings – estimated to represent about a fifth of the machine tool market.

Kendle says the caged roller guides will be priced similarly to conventional uncaged designs but he points out that, in many cases, a smaller and cheaper caged guide can be used because of its higher load capabilities.

The SRG is one of clutch of roller guides launched recently by THK. The others include: an ultra-wide caged-ball guide with a low centre of gravity; a compact caged-ball guide for use in restricted spaces; a corrosion-resistant guide that can work underwater; and a high-temperature guide that will work at up to 150°C. The company has also developed a ballscrew using caged ball technology.