Stanisław Adamczak

Amplitude Surface Texture Parameters of Models Manufactured by FDM Technology

The paper present test results of a measurement surface texture of models manufactured by FDM (fused deposition modeling) technology. The material used for constructing sample models was a structural material - ABS P430. A Dimension 1200es machine by Stratasys was used for the construction of the models. The process parameter, of which the impact on the quality of the surface texture was analysed, was the model orientation on a virtual building platform. A Form Talysurf PGI 1230, Taylor Hobson contact profiler was used for the measurements, and the test results were compared with the results obtained during the measurements with an optical profilometer.

Assessment of the Accuracy of Laser Vibrometer for Measurement of Bearing Vibrations

The advantage form no interference in the measurement system causes that Doppler laser vibrometers could be used in combination with other contact sensors, and also very helpful for tests determining the metrological properties of rolling bearing vibration measurement systems. Therefore, it is necessary to study problems related to the impact of the laser beam on the external surfaces of the tested bearings, as well as to determine the scope of use of laser vibrometers in the study of bearing vibration measurement systems.

Problems of Mathematical Modelling of Rotary Elements

Rotary elements constitute a large and significant group of machine parts. Such parts are used in various branches of industry, for example in bearing, automotive, paper, shipping or power industry. Most of rotary machine parts are cylindrical ones but sometimes other types of elements are used, as spheres, cones or barrel-shaped and saddle-shaped elements. Measurements of form deviations of such elements require performing a number of mathematical operations on measurement data, including calculation of reference features. The basis for such operations is to apply an appropriate mathematical model of the surface. Scientific literature and standards refer mainly to measurements of form errors of cylindrical shapes. Apart from the cylindrical surfaces, this paper discusses also the problem of mathematical modelling of cones, spheres and barrel-shaped elements.

The Evaluation of a Contact Profilometer Measuring Tip Movement on the Surface Texture of the Sample

Measuring instruments based on contact methods are commonly used in industrial, as well as laboratory conditions for the evaluation of geometric structure of the surface elements of machine parts. One of the flaws of such measuring systems is the risk of damaging a measured surface due to the contact with the measuring tip. The paper discusses research aimed at evaluating the impact of a stylus profiler measuring tip passage on the condition of the surface layer of samples made from three different materials, i.e. C45 steel, EN-AW-2017A aluminium and Vero White liquid resin. The tests involved thirty measurements of surface roughness of the selected samples and evaluating the changes in the basic roughness parameters due to the passage of a profiler measuring probe. The condition of the analysed samples was evaluated after the roughness measurements using a Talysurf CCI non-contact profilometer. The tests demonstrated that a multiple passage of a stylus profiler measuring tip influences the change in the measured surface roughness parameters. Moreover, the roughness measurement on the surface of a sample made from EN-AW-2017A aluminium caused a clear scratch.

Analysis of the Impact of Ball Bearing Track Waviness on Their Frictional Moment

Frictional moment is one of the parameters that determine the time and quality of working bearings. Therefore, it is important that it is possible to accurately predict the value of the frictional moment. This article analyses the impact of the track waviness on the frictional moment. In the research, a correlation analysis of selected wavelength parameters and frictional moment was performed and frictional moment. Those parameters wavelength are not included in the models used to determine the theoretical value of the frictional moment.

Comparative study of selected bearing vibration measuring systems

Measurement of vibrations generated by the rolling bearing is one of the most important elements of quality control [1, 2]. Leading bearing manufacturers use self-made measuring equipment or a specific supplier. Fig. 1 presents a diagram illustrating the principle of industrial measurement of vibrations of rolling bearings [3]. The measurement consists in recording the radial vibrations of the bearing superimposed on the shaft rotating at a specified speed. For the most part, an electro-dynamic sensor that generates a signal proportional to the vibration velocity is used for this purpose. The rolling bearing during axial load is axially loaded with a force with a force corresponding to the type and size of the bearing. To obtain accurate information on the state of the object being studied, the measurement signal is filtered into three frequency bands. In each of the bands, the effective vibration value is calculated, informing whether the examined bearing has significant defects [2, 4, 5]. The level of vibration generated by the bearing should meet the clients expectations. Standards concerning vibration measurement of rolling bearings are determined only by the general measurement conditions, such as: the rotational speed of the inner ring of the bearing, the clamping force of the outer ring or the method of filtering the obtained signal [6, 7]. There are no standards setting limits, which should not be exceeded by the level of vibrations. Usually this is a matter of internal company standards or a reconciliation between the producer and the recipient. Standards also do not determine how to provide measurement conditions technically. The existing systems differ, therefore, in some structural solutions of their subassemblies. Each of these components has a greater or lesser impact on the accuracy of the measurement.

The analysis of the impact of the design parameters on the friction torque in ball bearings

One of the many factors influencing the frictional moment in the bearings are construction parameters. These parameters include curvature ratio (the ratio of the radius of the track to the diameter of the ball) and the accuracy of the track shape. Although these factors influence the frictional moment, they are not included in the model used to determine the theoretical frictional moment. In this article, an analysis was carried out to determine the quantitative impact of the curvature ratio at the frictional moment in ball bearings. In order to * Kielce University of Technology, Department of Manufacturing, Engineering and Metrology, al. Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland, tel. 41 34-24-434, e-mails: adamczak@tu.kielce.pl; lgorycki@tu.kielce.pl; wmakiela@tu.kielce.pl. T R I B O L O G I A 5-2016 12 determine the quantitative effects of this parameter, a linear regression analysis was carried out on five groups of bearings and under five measuring parameters (the rotational speed, the radial and axial load and curvature ratio of the inner and outer ring).

Assessment of an Influence of Real Values of V-Block Method Parameters on the Method Accuracy of V-Block Waviness Measurement of Rotary Machine Parts

The article deals with an application of the V-block method to waviness measurements of rotary mechanical parts. The most popular methods used to measure waviness profile are radial ones. These methods are characterized by a high measurement accuracy and they are usually used to measure waviness profile of small parts under laboratory conditions. Furthermore radial waviness measurements are time-consuming due to centering of measured object on measuring table. Since, large size cylinders are used in many branches of industry, it is necessary to develop another method that allows to determine waviness deviations under industrial conditions. For this purpose the V-block method can be applied. This article presents a design and a principle of operation of a measuring device based on the V-block method. The device was used in the experimental part of the research work to measure waviness profiles. Paper describes also the procedure of identification of real values of V-block method parameters (angles α and β) used in measuring device. For the nominal and real values of angles α and β an experimental V-block method accuracy was calculated. The research result presented in this article indicate that the identification of real values of V-block method parameters increases the method accuracy.