Noack G. Berechnung hydrodynamisch geschmierter Gleitlager dargestellt [ 19] VDI Richtlinie ; Düsseldorf –  Lang O R, Steinhilper W. Gleitlager. VDI-Z. () 14, p. Lang, O.R.: Moderne Berechnungsverfahren bei der Auslegung von Dieselmotoren. 69 Lang, O.R.; Steinhilper, W.: Gleitlager. O.R. Lang and W. Steinhilper. Gleitlager. Springer, A. Boyaci, H. Hetzler, W . Seemann, C. Proppe, and J. Wauer. Analytical bifurcation analysis of a rotor.
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Munsterman, About the Author M. The AE-sensor was mounted on the outside of the housing Figure 3. The initial bearing lant can be recognized where the loading force at the bearing was gradually increased up to 4. In this region, the two machine surfaces are separated by a lubricant film. To establish a relationship between these results and the other measured variables at the test bench, the integral of the frequency spectra values in ranges between 80 kHz and kHz was calculated to characterize the AE signal.
This procedure clarifies that with the AE signal a bearing failure can be recognized seconds before it occurs. Further analysis is required to fully explain the extent to which each of the measured variables influence the acoustic signal.
These results support an argument for the use of AE analysis to be used as a condition surveillance method for sliding bearings based on the correlation between the friction condition and the measuring average noise level. The monitoring of the bearing back temperature, which is often used to supervise bearings, clearly reacted later than the AE signal. These vibrations are attributed to the noise emitted by the test bench gkeitlager.
The characteristic curve falls to a minimum value and then increases. Speed of the shaft can vary between and 3, rpm. The Best Gets Better: At the beginning of the measurements, the same frequency pattern is consistent with those seen in Steinnilper 4.
The region up to the minimum of the Stribeck-curve is determined through boundary and mixed lubrication. In this instance, a bearing failure could be induced by applying slight loading forces.
Monitoring Lubrication Regimes in Sliding Bearings
A detailed examination of the variables, which are normally involved in the friction process, determined that physical and mechanical parameters of the friction surface, where steel surfaces were involved, did not generate gleitlsger differing results. Sliding Bearing Test Bench.
After testing, the sliding bearing was classified as defective. Relative to engine analysis, there are no changes required for the engine compartment, cabling or housing configurations. The failure of a bearing in a ship motor may represent a threat to the machine, ship and environment, as well as to human lives. Acoustic Emission Analysis The evaluation of machines by noise monitoring in the audible sound range is a commonly used method.
Stribeck Curve The region up to the minimum of the Stribeck-curve is determined through boundary and mixed lubrication. Shaft Rotational Speed, Loading Force: In addition, the slight increase of the amplitude between kHz and kHz is characteristic of the intact running bearings. Result of Static Applied Load Test on Half-shell Glyco 40 Bearing In Figure 6, the value of this integral is given next to the progress courses of load, torque and bearing back temperature.
Monitoring Lubrication Regimes in Sliding Bearings
Measurement of the noise level can be done far away from the metallic contacts, even outside of the housing, and therefore requires no type of mechanical changes in the engine compartment.
This can be caused in boundary, mixed or elastohydrodynamic lubrication regimes as well as by the appearance and propagation of cracks, fracture processes, cavitations phenomena and phase changes, or through plastic deformations.
The progress of the bearing damage can be clearly observed. Sliding Bearing Test Bench The test bench enables testing with half- and complete shells. Friction and wear increase quickly, leading finally to a failure of the bearing. The loading force was increased to the point where asperity contacts began to occur. Time Variation of the Frequency Spectra In Figure 5, the variation in time of every frequency spectral analysis is properly arranged. For continuous surveillance systems, significant storage and processing capacity is required to manage the relatively large amounts of data and processing algorithms.
The evaluation of machines by noise monitoring in the audible sound range is a commonly used method.
Conclusions These studies demonstrated that acoustic emission analysis is an appropriate measurement procedure to detect incipient failures at sliding bearings through the correlation between the emitted acoustic signal and the energy dissipated in the sliding metallic contacts. The result of the measurement using a Glyco 40 half-shell under slowly increasing continuous load, with a speed of 3, rpm, is represented in Figure 5.
This course corresponds with the progress of the Stribeck-curve which describes the correlation between sliding speed and friction coefficient in sliding contacts Figure 2. Lng the tests, lead-copper-tin-bearings of the type Glyco 40 and bleitlager with a diameter of The adjusted limiting of gleitoager level plays a central role in this procedure, while amplitudes too high or too low can generate incorrect diagnostics.
All of the variables – shell material, speed, temperature and lubricant viscosity – are of interest. In experiments carried out with axial and radial bearings, gpeitlager density of impulses was determined in order to evaluate the acoustic signal at high frequencies. Further investigations presented similar results although bearing shells with different diameters and materials were used.
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Machine-specific data collection parameters and data management functions will need to be developed to enable integration of the right criteria, and identification of incipient failure. This response is characteristic to all the tests conducted and was observed in the generation of bearing damage.
The test bearing is located between both supporting bearings, which can be loaded using a hydraulic cylinder with a static loading force of up to 60 kN 13, pounds Figure 3. Measured parameters such as speed, driving torque, loading force, bearing rear temperatures and inlet steinhilpre temperature were determined.
High value is placed on the construction of compact machines and, therefore, improved thermal and mechanical efficiency is required.
The transferability of these results to nonstationary loaded bearings, for example in combustion engines, remains uncertain and its investigation could become the main purpose for further works. To document the progress of the bearing failure, the acoustic signal was measured and evaluated continuously every second. It can be mounted far away from the metallic contacts and therefore outside of the housing. Therefore, it must be measured in an ultrasonic range, at approximately kHz, where normal operating vibrations of machines and engineering equipment have no influence.
Acoustic Emission Mean Amplitude vs. Under unfavorable circumstances, the minimal lubricating gap becomes so small that a complete hydrodynamic separation of shaft and bearing is no longer guaranteed.