Rotary indexing unit for machine tool - has pneumatic braking of spindle mechanically amplified by balls riding on inclined thrust surfaces

摘要

The rotary indexing unit consists of a housing (11) with spindle (12) and work table (13) driven by a worm and worm wheel (16, 15). At the back end of the housing is an end cover (20) forming a pneumatic cylinder with piston (24) sliding on surfaces (21). Recessed into the front face of the piston is a support plate (26) which can move with or relative to it. When pressurised air is admitted to chamber (33), balls (30) is a sloping sided ring channel (29) formed in the piston and support plate force the rotating (17) and fixed (27) braking disks together, thus clamping the spindle. The brake is released by admitting pressurised air to chambers (31) behind the support plate. ADVANTAGE - High braking force with low pneumatic pressure. Simple design with low production cost.