KARGO - Cylindrical grinding machines

The wide range of grinding wheelhead variants ensures great flexibility. Up to two grinding wheelheads can be mounted simultaneously and each one of them can be equipped with up to three grinding spindles. This means that even complex workpieces requiring several grinding tasks can be ground in one machine and in one clamping. Extremely quiet operation is ensured by the direct-drive grinding spindles - made by JUNKER. They are equipped with structure-borne sound sensor and dynamic balancing system.

On the KARGO, the wheelhead moves with a cross-slide along the main axes in the X and Z directions. Thanks to the cross-slide design, the footprint of the machine is economical - despite the overall part size. Direct drives with linear motors ensure high dynamics of the main axes as well as very high positioning accuracy. Both the X and Z axes are equipped with high-precision linear recirculating roller bearing and guideway assemblies. The large distance between the guides of the X and Z axes ensure a stable design with high precision for the large grinding tools of the KARGO.

The B-axis of the grinding wheelhead is driven by a backlash-free gear. Each angular position is freely programmable. The generously dimensioned motor ensures short swiveling times and thus also reduces the machine‘s downtimes.An integrated length measuring system enables a pitch accuracy of ±1 angular second and a repeat accuracy of ± 0.1 angular seconds.

Thanks to a measuring system that swivels in when needed, various diameters can be measured in process, as well as post-process. A programmable linear axis allows the measuring system to be positioned freely along the length of the workpiece. The control system trades the measured values, calculates the correction and thus compensates for process influences due to temperature fluctuations or grinding wheel wear.

The workhead is mounted directly on the machine table. The workpiece is driven by a direct-drive spindle, designed for high moment rigidity and extraordinary dynamics. The use of high-precision roller bearings ensures smooth running with very high radial and axial runout characteristics.

• A standardized geometry of the spindle nose allows the flexible use of various clamping and driving systems.
• An integrated measuring system - in combination with the high-precision main axes - allows precise grinding of non-circular workpiece shapes.

The tailstock is mounted on the machine table and is positioned on the same guide as the workhead. A large quill diameter ensures optimum stability for grinding between centers of particularly heavy workpieces. At the same time, the clamping pressure can be adjusted as required. The spacious design of the quill stroke and a pneumatic support for adjusting the tailstock allow flexible machining of different workpiece lengths.

The dressing of the grinding wheel is CNC-controlled. Single point and rotary dressing can be used. The dressing discs can be mounted either on the workhead spindle or on the tailstock. Special developed dressing spindles made by JUNKER, are applied when rotary diamond dressing technology is used. Dressing is performed manually or via an automatic dressing program with grinding wheel compensation.

The machine bed made of mineral casting offers impressive absorption performances and torsional stiffness. Thanks to its temperature stability, fluctuations in the ambient temperature can be easily compensated. This ensures high dimensional stability throughout the production shift. 

A swirel measuring head measures the axial position of the workpiece on a flat surface in order to compensate for blank fluctuations. The measured values are automatically considered in the grinding process and the control system..

The Erwin Junker Operator Panel EJOP was specially developed for controlling grinding machines. All machine components are controlled via the operator panel - regardless of the series and the control system used. The identical structure, intuitive menu navigation and visualization of the workpiece geometry make operation extremely user-friendly and flexible. Programming is performed directly via the operating panel or via an external programming tool.

The new JUWOP II software is used to program workpieces using associated cylindrical grinding operations. The using universal cycles, geometries and technologies are created in conjunction with workpiece and technology assistants, and allow a very efficient programming of the grinding task. The program is created directly on the machine control or, optionally offline, on a work station.

Large workpieces are usually ground on the KARGO using conventional abrasives such as corundum. Depending on the application, CBN or diamond can also be used as abrasives. Both emulsion and mineral or synthetic oils can be used as coolants.

In case of an fire, the machine interior is automatically hermetically sealed, suffocating a fire before it has a chance to spread. If required, extinguishers (CO² or water mist systems) and exhaust air purification systems can be additionally installed. A competent partner for fire protection and filtration solution solutions is LTA Lufttechnik GmbH, which also belongs to the JUNKER Group and which researches, develops and produces filtration systems for industrial air purification.

The Filtration systems