The monitoring of rotating machinery is increasingly important for industry. Partly, it is made from indicators given by vibration analysis. These indicators give only the overall state of operation of the studied machine. Indeed, the piezoelectric sensors, which are used for vibration analysis, record the vibrations generated by the various components of the machine. Numerous studies have deve...

A new method to detect coal gangue interface by utilizing vibration signal of coal and gangue is presented for coal and gangue interface detection on fully mechanized mining face. Because of non-stationary characteristics contained in response signals under complicated environment, empirical mode decomposition algorithm was used to decompose the original vibration signal into the intrinsic mode...

Technical preventive measures against vibration syndrome in the field of industrial health are reviewed in the present paper. The first technical prevention measure is to reduce vibration transmission from the tools to the operators. This measure employs vibration isolators between the handles and vibration sources of machine tools. Handles of tools using Neidhalt dampers, shear type rubber mou...

This paper deals with the nonlinear models of regenerative chatter on machine tools. The limitations and actual problems of the existing theory are summarized. These cause difficulties in industrial applications, like in the design of optimum technological parameters, adaptive control and/or vibration-suppression strategies. An industrial machine-tool vibration case is analysed experimentally a...

Productivity in modem machine tools is acheved by using high cutting velocities, spindle speeds and feed rates. A restriction for large material removal rates is the tendency of machines to chatter (structural vibration) for large depths of cut. This work is concerned with improving machine tool performance by understanding and ultimately controlling vibration in machine structures. If vibratio...

With the development of intelligent machine tools, monitoring the vibration by the accelerometer is an important issue. Accelerometers used for measuring vibration signals during milling processes require the characteristics of high sensitivity, high resolution, and high bandwidth. A commonly used accelerometer is the lead zirconate titanate (PZT) type; however, integrating it into intelligent ...

This paper presents a new approach to machine health monitoring based on the Approximate Entropy (ApEn), which is a statistical measure that quantifies the regularity of a time series, such as vibration signals measured from an electrical motor or a rolling bearing. As the working condition of a machine system deteriorates due to the initiation and/or progression of structural defects, the numb...

Automated massage machines have been widely used in family for the past few years, but there was limit scientific evidence to support for them positive effects. This paper aims to evaluate the massage effects on recovery of muscle fatigue and explore the optimal massage machine design parameters. Two subjects participated in prone bridge exercises to make the erector spinae muscles fatigue befo...

This article presents a new vibration diagnostic method designed to (PM) machines with permanent magnets. Those devices are commonly used in small wind and water systems or vehicles drives. The author’s method is very innovative and unique. Specific structural properties of PM machines are used in this method electromotive force (EMF) generated due to vibrations. There was analysed number of pu...

Although the risks associated with vibration exposure have been known for a long time, the importance of risk prevention has increased in Europe since the implementation of the Machine Directives in 1989 (1989/392/EC) and the Vibration Directive in 2002 (2002/44/CE). These Directives challenged manufacturers to design low-vibration tools, and employers to manage the site-specific risks of vibra...