Inside-out pivoted-pad bearing with controllable stiffness

• Autorzy: Adams Jr. M. L. , Laurich M. A.
• Języki publikacji: EN

Abstrakty

EN

It has recently been demonstrated that high-speed grinding principles can be applied to the finishing of silicon nitride (ceramic) with considerable improvements in throughput, costs, and quality. This will require new high-speed high-power centerless grinding machines (7.000 rpm, 50 hp), with high-stiffness (2.000.000 lb/in) spindles. To meet the life, stiffness and speed requirements of this next generation grinding spindle, a novel inside-out, three-pad, pivoting-pad oil-fed hydrodynamic journal bearing has been devised, built and tested. The journal rotates externally about the bearing pads which are thus loaded against an internal shaft diameter. That is, an inside-out version of the conventional pivoted-pad journal bearing. Two of the three pivoting pads have fixed-support pivot points while the third pad’s pivot point is supported by a hydraulically-actuated radial-motion loading piston. This radial pad actuation provides a real-time controllable preload to the other two bearing pads and thereby controls the overall stiffness of the bearing. With this new bearing design, it is now possible to control spindle support stiffness, in real time, providing less-stiff spindle bearings for initial rough grinding and very high stiffness spindle bearings for precision finish grinding. Extensive bearing test data compare favourably with theoretically predicted bearing performance.

Słowa kluczowe

EN

bearing; privoted-pad; spindle; centerless grinder; actuator

PL

hydrodynamika; łożysko; wrzeciono

• Wydawca: Oficyna Wydawnicza Uniwersytetu Zielonogórskiego
• Czasopismo: International Journal of Applied Mechanics and Engineering
• Rocznik: 2005
• Tom: Vol. 10, no 3
• Strony: 395--406
• Opis fizyczny: Bibliogr. 7 poz., rys., tab., wykr.

Twórcy

autor

Adams Jr. M. L.

• Mechanical and Aerospace Engineering The Case School of Engineering, Case Western Reserve University Cleveland, Ohio, 44106-7222, USA

autor

Laurich M. A.

• Mechanical and Aerospace Engineering The Case School of Engineering, Case Western Reserve University Cleveland, Ohio, 44106-7222, USA

Bibliografia

• [1] Adams M.L. (2001): Rotating Machinery Vibration - From Analysis to Troubleshooting. - New York: Marcel Dekker, p.354.
• [2] Adams M.L. and Makay E. (1981): How to Apply Pivoted-Pad Bearings. - Power: McGraw-Hill.
• [3] Adams M.L., Sawicki J. and Capaldi R. (1992): Experimental determination of hydrostatic journal bearing rotordynamic coefficients. - Proc. of the 5th International Conference on Vibration in Rotating Machinery, J. Mech. E., Bath, September 1992.
• [4] Kovach J.A. and Malkin S. (1998): High-Speed, Low-Damage Grinding of Advanced Ceramics Phase 2- Final Report. - Oak Ridge National Laboratory, June 19.
• [5] Laurich M.A. (1999): Inside-Out Pivoted-Pad Centerless-Grinder Journal Bearing with Controllable Preload and Stiffness Controllable Preload and Stiffness. - M. S. Thesis, Case Western Reserve University, May 1999.
• [6] Reynolds O. (1886): On the theory of lubrication and its application to Mr. Tower's experiments. - Phil. Transactions of the Royal Society, vol.177. Part l, London, England.
• [7] Szeri A.Z. (1998): Fluid Film Lubrication - Theory and Design. - Cambridge: Cambridge University Press, p.414.