Just what the doctor ordered – precision linear motion systems

Medical scanning equipment is an application area in which NSK provides complete assemblies to manufacturers, including linear guides and ball screws. A typical example in an MRI scanner is the motorised ball screw supplied by NSK, used for its extreme accuracy and repeatability says the company. In some cases the units must deal with heavy loads and still produce movement that is sufficiently smooth and consistent to generate clear, reliable results.

As the name infers, MRI technology requires the use of high magnetic forces, so the ball screws and other components provided by NSK need to function in this type of environment without any adverse effect on the overall  performance of the machine. NSK says that other types of ball screw often feature circular arc grooves, where balls can get wedged: so NSK uses offset gothic-arch style grooves to avoid this by minimising the clearances between the balls and the grooves. Further, the company states that durability is boosted through the use of purified alloy steel, while any potential for backlash is eliminated thanks to an application of preload.

NSK says that a popular choice amongst designers of medical imaging systems are its NH linear guides, which it claims offer double the lifespan of conventional products due to the inclusion of features like specially developed ball groove geometry. Further benefits highlighted by NSK include high dynamic load rating, long maintenance intervals, low noise output and simple installation. The company also confirms that all its linear guides and ball screws can be customised to suit individual requirements.