Low-profile Bearing Offers High Precision
The FMB turntable bearing is designed to provide high-performance circular motions in as small a package as possible.
The FMB bearing from Micromech is a low-profile, high-precision rotary bearing ideal for positioning systems where both precision and height is critical. The various bearings sizes are only 8.5 to 12.5mm tall yet deliver radial and axial run-out from 10 microns down to 1 micron and wobble from 6 down to 2 micron-rads.
The very thin and compact precision bearing is a turntable bearing designed to provide high-performance circular motions in as small a package as possible.
The bearings are currently available in nine standard sizes with ODs ranging from 120 to 350mm and IDs ranging from 40 to 250mm and for OEM applications, custom sizes are available up to 500mm OD to exactly match the application.They can support axial, radial and moment loading, have high rotary precision and repeatability, and provide significant cost savings up to 50% of classic turntable versions.
Classic turntables are designed by using a double pack of bearings which are often, complex making them costly as they use more components.Assembly must also be performed by trained workers.The FMB design is much simpler with just one bearing having only one inner and one outer ring, achieving significant cost savings.
The bearings are made from high-quality bearing steel 1.3505 with a through hardness of 60+/-2HRc.If required by the application they can be manufactured in stainless steel No.1.4034.The super precision balls are made from bearing steel 1.3505 with a hardness of 62+/-2HRc.
These balls are spaced evenly in a PTFE-filled plastic ball cage.The bearings are manufactured in normal and precision grades and are supplied by default with zero clearance.
The FMB can operate under different conditions and therefore supplied in two preload classes V0 (0.02C) and V1 (0.08C): V0 for very smooth almost friction-free operation; and V1 where the location requires high rigidity and is subjected to vibrations or large overhung loads.
They are very easy to install as most rotary bearings fit into a bore which must be very precise to avoid deforming the bearing and spoiling the precision.
The FMB includes a 0.5mm offset between the inner and outer races and counterbored holes to enable mounting directly onto flat surfaces.It is a single, four-point contact ball design, which consists of a single row of balls with a 'gothic arch' geometry raceway and PTFE filled plastic ball cage filled with super precision balls for low frictional torque.The special designed raceways are finished by precision grinding and the balls are selected within a tolerance of 0.1 micron.
Product Model | Inside Diameter | Outside Diameter | Thickness |
3204J2RS bearing | 20 | 47 | 20.6 |
3204J bearing | 20 | 47 | 20.6 |