Micromech is introducing the RSDE linear bearings that are based on the conventional crossed-roller linear version but, thanks to the deeper ground V-groove in combination with special designed cylindrical rollers, offer higher load ratings and stiffness without changing the envelope dimensions.
The construction comprises two pairs of opposing linear bearings; each pair consisting of two similar 90-degree V-groove guideways that are through-hardened and precision ground, with crossed rollers held within a cage between the guideways.
This arrangement results in a load capacity that is approximately three times higher than conventional bearings. A second major benefit is that the stiffness is doubled, due to the enlarged contact area of the running surface; the RSDE has an approximate 80 per cent stiffness factor compared with 35 per cent for conventional types. The compact design also helps to prevent dust and dirt from entering the inside of the roller-ways, as the space between the roller-ways is reduced to a minimum.
Roller sizes are 3, 4, 6, and 9mm, and guideways lengths range from 50-1200mm. Guideway attachment holes are counterbored to a standard pitch configuration.
They are manufactured to extremely close tolerances, <2microns over the full guideway length; the surface roughness is <0.05Ra so that the V-groove has a 'mirror' smooth finish. This means vibrations in the sub-micron range are substantially reduced as well as friction, resulting in smooth-running linear motion.
These accurate but ruggedly built bearings will accommodate higher speeds and accelerations and therefore can be used in highly dynamic applications requiring high speed, high running accuracy and outstanding quality. This makes the RSDE most suitable for the semiconductor industry, measuring devices and material testing equipment.