The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 14, 2000
Filed:
Jan. 02, 1997
Kugalur S Chandrasekar, Rockford, IL (US);
The Ingersoll Milling Machine Company, Rockford, IL (US);
Abstract
A machine tool assembly, and particularly a spindle unit therefor, is provided wherein the spindle unit is relatively small and is designed to run at rotary speeds of between 30,000 rpm's and 40,000 rpm's utilizing hydrodynamic bearings for the spindle shaft. The hydrodynamic bearings are effective to take increased loads versus similarly sized conventional metal-to-metal contacting bearings to provide a very stiff machining system even with the higher loads generated by the increased rotary operating speeds for high speed machining contemplated for the spindle unit herein. The bearings are also designed to use a water-based fluid which is compatible with the cutting fluid. Non-contacting fluid barrier seals limit and control the amount of bearing fluid leaked to the cutting fluid. Due to the compatible nature of the two fluids, small fluid leakage from the bearings will not hurt the cutting fluid. The cutting fluid circulated at an ambient inlet temperature, e.g., 70.degree. F., and leaves at a higher discharge temperature, e.g., 120.degree. F., to cool the spindle and bearings.