Best Time Domain Features for Early Detection of Faults in Rotary Machines Using RAT and ANN

The common mechanical defect of rotating machinery is bearing failure which is considered the most common failure mode in rotating machinery. This kind of failure can lead to large losses as financial during work. Early detection of different faults in rotating machines such as bearing fault, misalignment, and others is considered one of the techniques in which is achieved by further signal processing techniques. Thus, using statistical methods such as reverse arrangement tests (RAT) to obtain the best a feature associated with these different faults is the perfect solution to find the failure which is widespread in the early detection of a fault. This type of feature will be used in Artificial Neural networks (ANN) as input for auto diagnosis. These characteristics are independently associated with different types of fault. Using RAT is considered very important in the process of linking different kinds of failures with the most important features.

Fault Diagnosis of Rotary Machine Using FFT (Fast Fourier Transformation) and Orbital Analyzer

In different industries we use different machines and most of the machines are rotary machines. The small fault in machine cause vibrations in machines. These vibrations may cause effect on machine or product produced by machine. So, it is important to study these faults present in the machines. In this paper we are going to discuss fault detection techniques. We are discussing two technique FFT (Fast Fourier Transformation) and Orbital Analysis. In FFT we are getting graphs with respect to frequencies and according to peak frequencies we predict fault while in Orbital Analysis we are getting different orbital shape graph and according to shape we predict fault in machine.

INFLUENCE OF INSTANT IMBALANCE AND POSITION OF HARDNESS CENTER ON VIBROACTIVITY OF HORIZONTAL DRUM MACHINES

The issues of reducing the vibration caused by rotating rotors at the frequency of the first rotor harmonic (so-called rotor vibration) are among the most important in the design, manufacture and operation of almost all types of modern rotary machines. The washing machine as an object of study of the dynamics and reduction of vibration and noise is of particular interest due to the constant presence of randomly located and wandering imbalance of laundry in the drum and low requirements for accuracy of its manufacture and assembly of parts and assemblies. A mathematical model of oscillations of a multiconnected tank-drum system on elastic suspensions for the main types of machines and spin centrifuges with a horizontal axis of rotation is created. The model is developed in a linear formulation based on the Lagrange equation of the II kind for a washing machine. The accuracy and adequacy of the mathematical model was tested directly on the field object by measuring noise, vibration, forces in the supports and stress distribution in the individual elements and components of the machine in the entire range of drum speeds. Studies of the nature of system oscillations depending on the change in position and attachment points of elastic and damping elements were performed using simulation in the Simulink environment. As a result of research, the basic requirements for the layout of horizontal rotary machines of the drum type were experimentally confirmed: the center of mass of the tank must lie on the axis of rotation of the drum; the axis of rotation of the drum should be the main central axis of inertia of the tank; the center of mass of the tank must coincide with the center of mass of the loaded drum; the center of rigidity of the system of elastic supports must coincide with the center of gravity of the tank, and the main axes of rigidity – with the main central axes of inertia of the tank; the main axes of the constant viscous friction must coincide with the main central axes of inertia of the tank. The results of the theoretical study were applied to the problem of evaluating the efficiency of a liquid auto-balancing device for a proper squeezing machine depending on its dynamics.