High-Speed Precision Boring Head
This high-speed boring head operates at 2500 to 3000 rpm, employing angular-contact, superprecision bearings. The front bearings are of different sizes. The outer ring of the larger bearing abuts and is clamped against the housing shoulder. The inboard bearing is permitted to move axially in its housing under spring load. At the rear location two bearings, of the same size and spring loaded, are allowed to float in the housing as temperature differentials occur in the operation spindle. With this head, interference shafts may be permitted without affecting bearing preload. Excessive heat generation is prevented, resulting in low operating tempera- tures. Bearings are grease lubricated.
Ultra-Precision Grinding Workhead
This workhead must maintain straightness and roundness accuracy within ten millionths (.000010) of an inch. To meet such rigid requirements for extremely close dimensional control, ultra-precision ball bearings and a shaft of extra stiffness are used. The bearings for such applications are manufactured to tolerances closer than those for ABEC-9 specifications. Equally important is the high degree of workmanship and accuracy with which the shaft, housing and component parts of the workhead must be made. Upper section shows a four-bearing arrangement for heavy work. Lower half shows a two-bearing mounting for lighter work. In either case, the bearings are packed with grease, prior to mounting.
Precision Toolroom Surface Grinder Spindle
Fafnir duplexed, superprecision, preloaded bearings used in this spindle provide the high degree of rigidity in both direc- tions necessary to meet requirements for modern surface grinding and to assure efficient performance at a low operat- ing temperature. The housing is bored straight-through to assure true alignment – the housing shoulders are eliminated. The precision ground outer sleeve is doweled to the housing to provide the means for stabilizing the spindle axially at the work end bearing location. The rear pair of bearings floats to compensate for thermal changes. Bearings are grease lubricated for life just prior to assembly.
Single Bar Machine
This spindle is supported by two pairs of 2MM9124WI-DUM superprecison bearings, mounted back-to-back in tandem pairs. Operating speeds vary from 78 to 1500 rpm. A pair of 2MM9122WI-DUM bearings mounted in tandem carry a 25,000 pound thrust load during the unchucking operation. The bearings are grease packed for life prior to assembly.