XHCCross-Harbour Tunnel (Hong Kong)
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According to [9], if we are using the variable change W = XHC, the poles of the system G(s) enclosed in the disk D (d,r,[theta])are equivalent to the existence of a solution X = [X.sup.T] > 0 as:
Speedy tooling was the goal of the XHC 240 high-speed machining center introduced by Ex-Cell-O GmbH in 1993.
Ex-Cell-O met these goals by equipping the XHC 240 with precision high-speed spindles and linear motors.
"The prototype of the XHC 240 is the first time we joined high-speed spindles and linear motors, which shaped our design considerations," said Hilmar Rudloff, sales manager for Ex-Cell-O's machining center product line.
The motorized spindles of the XHC 240 are capable of maximum speeds of 24,000 revolutions per minute.
The x, y, and z axes of the XHC 240 all use electrical direct drives with linear motors.
Intelligent, digital alternating current servo drives supply the linear motors used in the main axis of the XHC 240.
The combination of intelligent servo drives and swift, modular CNC enables the XHC 240 to look ahead, prepare blocks, conduct geometrical and mathematical interpolation in 2 milliseconds to perform position compensation for contouring and acceleration errors, and provide high position resolution.
The CNC table of the XHC 240 is equipped with a rotating direct drive on the b axis to guarantee high positional accuracy.
Chrysler Mexico has just bought seven of the XHC 240s in a cell configuration for machining three- and four-speed trans-axle transmission cases.
The XHC 240 is a remarkable machine in other ways, too.
Linear motors, limited then, it was said, by lack of dynamic stiffness, have become a critical component of a number of new machines including Ingersoll's HVM and Ex-Cell-O's XHC 240 high-speed horizontal machining center.