Precision flies

Aerospace Report

The aeronautical and aerospace sector has in AZ SpA a technological partner able to propose numerous specific grinding solutions with high innovative content. In the range of grinders designed by AZ, the new LBC777 line for the orbital machining of landing gear is a recent and very successful example. The aerospace sector is in continuous technological evolution and seems not to know crisis. Direct, indirect EOM and certified aerospace subcontractors always research and develop innovations for all components and processing processes used, for example, new "hyper-special" materials such as inconel, high-alloy steels, super alloys with base of cobalt and nickel, titanium etc.

Aerospace also means working on very expensive single pieces and following strict production procedures with special work cycles that guarantee their traceability and above all "zero defect" on the final pieces. For machine tool suppliers, and in particular for finishing machines such as grinding machines, no mistakes are allowed.

In this context, among the manufacturers of cylindrical grinding machines accredited for aerospace, the Italian AZ SpA of Thiene (VI) has been able to gain a worldwide leadership success thanks to the high quality and performance levels of its products. This is the result of high professionalism and engineering creativity able to grasp and often anticipate market demands. AZ has an impressive range of grinding solutions designed specifically for the aerospace industry called "AZ Aerospace" for the manufacture and maintenance of components of aircraft engines and landing gear. AZ grinding machines are all customisable, energy efficient, safe, reliable and comply with Industry 4.0 requirements.

The numerous lines available are developed with the range AKP for landing gear grinding machines with gap bed, GSB for internal landing gear grinding machines, RU and RUG for universal grinding machines for external and internal diameters and LBC for landing gear orbital grinding machines for external and internal diameters. In particular, the new LBC777 represents a recent example of a solution for asymmetrical heavy parts with rotating table. One of these grinding centres is successfully used for all Boeing series with others for alternative brands of landing gear. A new self-balancing orbital grinding system and rotary table facilitates the grinding of the heavy-duty landing gears without displacement of the workpiece. In fact, the rotary table allows the grinding of external and internal diameters in a single piece grip and is moved by the overlapped and crossed arrangement of the main machining axes, Z and X, which allows ample operating capacity with reduced dimensions on the ground. The machine axes slide on high precision recirculating linear guides. The machine base has been designed with FEM analysis and is made with a special

“Composital” technology structure that reduces the elasticity coefficient, guaranteeing an exceptional absorption of vibrations, great machine rigidity, stiffness and high dynamic performance.

The LBC777 wheelhead is configured with two spindles for internal grinding and one spindle for external grinding. The wheelhead, mounted on a rigid structure, is equipped with an AZ system for self-balancing and runs vertically in the Y-axis, on sliding guides with anti-friction material "Turcite" equipped with automatic lubrication. The grinding machine is characterised by the particular processing cycle that takes place through the orbital grinding of the workpiece surface. On the stationary piece and positioned by the rotating table, the grinding wheel used follows the geometric trajectory of the piece along its generating line both for grinding external and internal diameters. With this axis scheme, the machine allows an internal grinding capacity from 70 up to 900 mm, an external grinding capacity from 10 up to 450 mm and a tangential grinding capacity of 2,000 x 850 x 1,500 mm. Silicon carbide, corundum, CBN and diamond grinding wheels allow grinding all aerospace materials, metals and their alloys including chromium and, in particular, those subjected to the most innovative systems for thermal spray techniques, such us H.V.O.F. (High Velocity Oxygen Fuel). The grinding process has some functions to give to the operator few automatic and safe working cycle: electronically variable spindle speed, GAP control, dressing control, CRASH

control and control of orbital diameters from CNC. This offers the machine the

possibility to reach unbelievable performance on accuracy. In addition, Wikicam is a monitoring system that allows to control remotely some parameters of the

CNC machine. There is also a built-in live video streaming solution to monitor what the machine is doing in real-time. The connection to the builder's headquarters is made by a high-strength secure encryption algorithm, using a VPN.

The grinding machines produced by AZ use the most advanced mechatronic solutions. Measurement systems, motors, drives, as well as machine mechanisms and applied CNCs, are selected among the best brands in the world. With over 40 years of experience in the sector and more than 3,000 grinding machines delivered and operational in more than 80 countries worldwide, AZ has always distinguished itself in tackling and solving technical issues, even with complex shape, proposing customised solutions to individual customer needs. The design creativity of AZ allows the creation of product lines, like the new LBC777, to be among the most sophisticated on the market today.