| 摘要 |
1,203,483. Grinding. SOC. NOUVELIE DE ROULEMENTS. 23 May, 1968 [26 May, 1967], No. 24776/68. Heading B3D. A hydro-dynamic spindle assembly comprises a spindle 2 for rotation and axial reciprocation in hydro-dynamic bearings 3, 4, the axial reciprocation of the spindle being effected by hydraulic pressure applied to the spindle and transmitted to a tool, such as a grinding wheel, directly by the spindle, the pressure and its regulation being controlled by a distribution device and the fluid being utilized to lubricate the bearings of the spindle. Each hydrodynamic bearing comprises three bushes supported in the body 1 of the assembly. The spindle is formed with a collar 10 acting as a piston located between a pair of rings 12, 13 and defining chambers 14, 15 alternately supplied with fluid pressure from a valve 18 having a spool 30 reciprocated by a crank 31 to reciprocate the spindle. Fluid pressure from the chambers passes through gaps between the spindle and rings to the bearings 3, 4. The ends of the stroke of the collar 10 are limited by hydro-dynamic stops formed by wedges of fluid in V-shaped slots 38 in the rings 12, 13. |
