Adjustable preload, high-speed spindles

April 20, 2000
New GHS motorized spindles from Russell T. Gilman Inc., Grafton, Wis., have "Dynamic Preload Control" that lets users vary spindle stiffness while machining.

New GHS motorized spindles from Russell T. Gilman Inc., Grafton, Wis., have "Dynamic Preload Control" that lets users vary spindle stiffness while machining.

This comes in handy for machining different materials, such as aluminum and cast iron, that require different speeds. Typically, for high-speed aluminum milling, bearings need to have light preload. On the other hand, a slower pace and stiffer spindle is needed for machining cast iron, so the bearings need to be stiffer. Springs have been used to adjust bearing preload but often do not provide enough control to machine both cast iron and aluminum with the same spindle. The GHS motorized spindle can do both.

Hydraulic fluid is used to preload the bearing set. Pressure is applied to the bearings which, in turn, increases the preload. Operational adjustments are always maintained within the bearing parameters. Dynamic preload control also eliminates natural frequency harmonics and chatter typically found in machining processes.

The spindles are powered by three-phase, four-pole induction motors rated for 380 V. An automatic power draw bar lets coolant and air pass through the spindle shaft and features three sensing switches that provide tool change feedback to the control.

Spindle sizes range from 120-mm cartridge diameter, 7 kW, 36,000 rpm, to 230-mm cartridge diameter, 36 kW, 18,000 rpm.

Sponsored Recommendations

Pumps Push the Boundaries of Low Temperature Technology

June 14, 2024
As an integral part of cryotechnology, KNF pumps facilitate scientific advances in cryostats, allowing them to push temperature boundaries and approach absolute zero.

The entire spectrum of drive technology

June 5, 2024
Read exciting stories about all aspects of maxon drive technology in our magazine.

MONITORING RELAYS — TYPES AND APPLICATIONS

May 15, 2024
Production equipment is expensive and needs to be protected against input abnormalities such as voltage, current, frequency, and phase to stay online and in operation for the ...

Solenoid Valve Mechanics: Understanding Force Balance Equations

May 13, 2024
When evaluating a solenoid valve for a particular application, it is important to ensure that the valve can both remain in state and transition between its de-energized and fully...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!