Timken Super Precision Bearings for Machine Tool Applications

Lubrication Guidelines for Higher Speed Bearings
A precision tapered roller bearing can meet almost any level of
speed required by the machine tool industry with the TSMA and
Hydra-Rib high-speed bearing designs, providing circulating oil
lubrication can be accommodated.
Both the lubricant and lubrication system have an effect on heatgeneration
and heat-dissipation rates and thus are important to the
speed capabilities of a bearing.
The choice of lubrication will depend on:
• Maximum speed requirement.
• Heat dissipation rate of the system.
• Spindle layout.
• Orientation of the spindle.
Special high-speed bearings with circulating oil
Oil jets
Oil mist
Circulating oil
Oil level
Grease
Speed guidelines
Typical industry experience indicates no problems
under ordinary circumstances.
Industry experience indicates testing may be
required to optimize system.
Testing will be needed and special bearings may be
required to achieve these speeds.
Internal Bearing Design – G 1 Factor
ENGINEERING
Internal bearing geometry has a direct influence on torque
and, therefore heat generation. In order to rate the torque/heat
generation characteristics of its bearings and to assist designers in
selecting appropriate bearings, Timken developed a factor called G 1:
the lower the G 1 factor, the lower the heat generation. The G 1 factors
are published in Timken catalogs and are listed in the appendix of
this catalog for the precision tapered roller bearing part numbers
listed in the tapered roller bearing section.
This G 1 factor is of prime importance to a designer because of the
influence of operating temperature on spindle accuracy.
A
0 10 20 30 40 50 100 200 m/s
0 2000 4000 6000 8000 10000 20000 40000 ft/min
dN
Fig. 56. Speed capability guidelines for various types of lubrication
systems.
TIMKEN MACHINE TOOL CATALOG 55