Bearing systems can be tailored to meet specific machine-tool needs. For instance, the top half of this graphic shows a spindle design for slower-running and higher-stiffness applications, such as heavy-duty milling and precision grinding operations. The bottom spindle is for lathes that require lower stiffness and higher speeds.
Manufacturers supply angularcontact ball bearings in steel and hybrid versions, in a wide variety of sizes and cross sections.Lathe spindles require bearings that can handle a range of load, speed, and stiffness requirements.Gilman block-type and cartridge spindles serve a wide variety of machine tooling applications.
Many of the latest advances in the design and development of machine tools have been driven by a need to reduce costs and improve productivity. Compared with units of only a few years ago, today's machine tools offer greater accuracy, higher speed, and greater stability, and with it moreefficient production. For example, CNC lathes now feature four linear axes enabling two tools to work simultaneously. Modularly designed and computer-controlled grinding machines adapt easily to perform different and multiple tasks. And spindles are frequently designed as separate units to allow for quick interchangeability and less downtime.
As these and similar machine tools have become more complex, demands on system components have likewise increased. Superior performance is expected system-wide, in particular from the bearings. Rigorous application demands have spurred development of high-precision bearings and bearing arrangements specially engineered to satisfy a wide range of exacting requirements.
Spindle-support bearings, for instance, must exhibit a range of characteristics typically beyond the reach of standard bearings used in general-purpose applications. Spindle applications often require one set of bearings at the tool side and another set at the drive side.