Strain field analysis and sensor design for monitoring machine tool spindle bearing force

• Published in: International journal of machine tools & manufacture Vol. 36; no. 2; pp. 203 - 216
• Main Author: TU, J. F
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1996; Elsevier
• Subjects: Applied sciences; Bearings, bushings, rolling bearings; Computer simulation; Cutting; Drives; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Machine tools; Mathematical models; Mechanical engineering. Machine design; Monitoring; Physics; Sensors; Solid mechanics; Static elasticity; Static elasticity (thermoelasticity...); Strain; Strain gages; Stress concentration; Structural and continuum mechanics; Fluctuations; Machine tool; Bearing(mechanics); Strain distribution; Simulation model; Elastic deformation; Experimental study; Rotation; Monitoring
• ISSN: 0890-6955; 1879-2170
• DOI: 10.1016/0890-6955(95)98761-U

The fluctuating strain field produced by the rolling motion of the spindle bearing is analyzed by an elastic model and verified with experimental data. This strain field analysis is of considerable practical significance because of its close correlation to spindle bearing preload, cutting forces, and bearing running conditions. Based on the model, a conventional sensing scheme with strain gages mounted in a groove ground around the bearing outer ring is optimized by selecting proper sensor sizes, locations, and configurations such that signal cross-over error is minimized. In addition, the feasibility of a non-invasive sensing scheme achieved by attaching high sensitivity sensors on the outside surface of the spindle housing is studied. From the strain model, it is found that the level of strain field at the housing surface is substantially lower, and its distribution is not concentrated. Therefore, high sensitivity sensors and different sensing schemes are needed. Simulation results show that, compared with the conventional scheme, the output of this scheme requires less signal processing when the force acting on the bearing is fluctuating.