Rotating Machinery Library for Diagnosis

Abstract

This paper presents our new rotating machinery library. Diagnosing the complex system accurately based on stochastic method requires an enormous amount of data, both with and without faults. Acquiring operation data with all kinds of faults for each components is very hard and costly. To generate data for rotating machinery diagnosis, we developed rotating machinery library using Modelica. It provides the basic components such as rotor, shaft, bearing, coupling, housing and support. Its component models are implemented on basis of rotor dynamics theory. This library makes it possible accessing rotating machinery operation data with various faults such as unbalanced rotor, shaft bending and ball bearing faults. To validate our models, we compared both Modelica simulation and experiment with a rotor kit as a test case.

Modelling of Asymmetric Rotor and Cracked Shaft

“…Proceedings of the 2nd Japanese Modelica Conference May 17-18, 2018, Tokyo, Japan system O -ξηrotating with the shaft (Figure 3 (b)) . Along the ξ direction, the restoring force has a linear spring (Gasch, 1976;Henry and Okah-Avae, 1976). The cracked shaft model is expressed as the extension of the asymmetrical shaft model.…”

Modeling of Rotating Shaft with Partial Rubbing

“…The presented rubbing force models must be supplied by constraints in the transverse direction x, y and rotating angle direction. Our Rotating Machinery library is used to supply these constraints (Ishibashi et al, 2017). The presented rubbing models are implemented in our rotating machinery library.…”

“…To carry out the analytical investigation of the experimental result, we built the Modelica model corresponding to the rotor kit based on our library shown in Figure 18. The parameters such as the bearing stiffness and damping, the residual bow (the bend of shaft) and the rotor static unbalance of the model were calibrated to match the preliminary experiments by the same method of the previous paper (Ishibashi et al, 2017). The rub screw stiffness and damping were estimated by the preliminary impulse test.…”

“…has been studied, both theoretically and experimentally (Watanabe et al, 2004;Watanabe et al, 2005). We have created the rotating machinery library by transfer matrix method in Modelica (Ishibashi et al, 2017). By transfer matrix method, the rotating shaft is decomposed into rotors, shafts, journals, couplings, housings and supports.…”

Modelling of Oil Film Bearings

“…In this Section, we derive the Reynolds equation in order to determine the force that the oil film exerts on the shaft, that is, the pressure distribution of the oil film (Hori and Kato, 2008;Ishida and Yamamoto, 2012;Matsushita et al, 2017). Figure 1 schematically shows both walls of the shaft and the bearing are separated by an oil film.…”