Swiss rotary tables on XYZ machining centres
Any vertical machining centre in the range offered by XYZ Machine Tools can now feature 4th and 5th axis machining utilising the high precision of the Swiss manufactured Lehmann rotary tables. Being of modular build thus meeting ‘future-proof’ requirements, the unit can achieve 180 deg positioning within 0.5 secs – half the time rating of competitor units while maintaining accuracy to 10 arc/secs.
Lehmann has specialised in NC tables and positioning equipment for over 35 years during which time more than 10,000 units have been installed. The compact design of the EA 500 series of three units has the rigidity of a cast iron base with hard chrome plated gear unit housing and an anodised aluminium cover to prevent damage from the likes of swarf and coolant in the machining area. The compact dimensions of each unit also means machine table area and Z-axis stroke is not compromised.
Being modular and using Lehmann’s CombiFlex system of build more than 20 different methods of component clamping can be applied as standard in conjunction with manual or power-operated devices. As a result, restrictions caused by normal faceplates, chuck jaw and clamping areas of other systems are overcome.
The gear-based indexing mechanism can be fine tuned for backlash if required during service life through radial adjustment of the worm. Also, the use of quadruple precision bearings provides maximum radial support against thrust generated particularly when drilling off-centre. Internal radial spindle clamping is on the maximum diameter with integrated pressure intensifier and pressure sensors that create a clamping factor between 300 and 4,500 Nm, a factor 10 times that of competitive products. This eliminates any axial displacement of the spindle and loading against the spindle bearing. Built-in intelligence displays history and speed, monitors internal pressure, temperature, moisture, shock and clamping data.
The 3 models EA507, EA510, EA520 have a clamping torques of 300, 800 and 2,000 Nm respectively, with an indexing accuracy of 20, 17 and 12 arc/secs. The weight of each unit is 22 kg, 35 kg and 70 kg and each respectively is able to support workloads of 240 kg, 400 kg and 800 kg.