Bearing Fault Model for an Independent Cart Conveyor
Independent cart conveyor system is an emerging technology in industries, trying to replace servo motors and kinematic chains in several applications. It consists of several carts on a closed-loop path, each of which can freely move with respect to the other carts. Basically, each cart is an servo linear motor, where the windings and the drives are on the frame and the magnets are on the moving carts together with a feedback device (e.g. a Hall sensor to track the position). The drive controls and actuates each cart independently according to the motion profile loaded. From a mechanical point of view, the carts are connected to the frame through a series of rollers placed on and under a mechanical guide. The rollers may be subject to a premature wear and the condition monitoring of these components is a no trivial challenge, due to non-stationary working conditions of variable speed profile and variable loads. This paper provides a bearing fault model taking into account the motion profile of the cart, the mechanical design of the cart, the geometry of the conveyor path, the expected loads and the type of fault on the roller bearings.
KeywordsIndependent cart system Ball bearings Fault model Linear motors
The authors are grateful for the National University Research Fund (FAR 2016) of the University of Modena and Reggio Emilia - Departmental and Interdisciplinary Projects (DR. 73/2017, Prot. n. 37510-27/02/2017) and the support from Tetra Pak Packaging Solutions.
- 1.Rockwell Automation: iTRAK The Intelligent Track System Increase machine flexibility and throughput to enhance overall productivity. http://literature.rockwellautomation.com/idc/groups/literature/documents/br/motion-br007_-en-p.pdf
- 2.Beckhoff Automation: XTS. The eXtended Transport System. https://download.beckhoff.com/download/Document/Catalog/XTS_Beckhoff_e.pdf
- 3.B&R: ACOPOStrak Ultimate Production Effectiveness. https://www.br-automation.com/smc/5adafdb3a7f954f17c8bb25652a8c971a38e4d94.pdf
- 4.Molano JCC, Rossi S, Cocconcelli M, Rubini R (2017) Dynamic model of an independent carts system. In: Advances in Italian mechanism science. Mechanisms and machine science, vol 47, pp 379–387Google Scholar
- 6.Poyhonen S, Jover P, Hyotyniemi H (2004) Signal processing of vibrations for condition monitoring of an induction motor. In: Proceedings of 1st international symposium control, communications signal processing, pp 499–502Google Scholar
- 9.Curcurú G, Cocconcelli M, Immovilli F, Rubini R (2001) On the detection of distributed roughness on ball bearings via stator current energy: experimental results. Diagnostyka 51(3):17–21Google Scholar
- 11.Hayes M (1996) Statistical Digital Signal Processing and Modeling. Wiley, HobokenGoogle Scholar
- 13.Salami M, Gani A, Pervez T (2001) Machine condition monitoring and fault diagnosis using spectral analysis techniques. In: Proceedings of the 1st international conference on mechatronics, pp 690–700Google Scholar