SURFACE STRAIN HARDENING FOR THE PERFORMANCE IMPROVEMENT OF HYDRAULIC ACTUATORS IN POWERED ROOF SUPPORTS

1 MIKUŁA Jarosław
Co-authors:
2 MIKUŁA Stanisław 3 SZWEDA Stanisław
Institutions:
1 Silesian University of Technology, Faculty of Mechanical Engineering, Gliwice, Poland, EU, jaroslaw.milkula@polsl.pl
2 Silesian University of Technology, Faculty of Mining and Geology, Gliwice, Poland, EU
3 KOMAG Institute of Mining Technology, Gliwice, Poland, EU, sszweda@komag.eu
Conference:
28th International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 22nd - 24th 2019
Proceedings:
Proceedings 28th International Conference on Metallurgy and Materials
Pages:
432-437
ISBN:
978-80-87294-92-5
ISSN:
2694-9296
Published:
4th November 2019
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
129 views / 41 downloads
Abstract

In the paper working conditions and requirements for cylinders of hydraulic actuators, used in mining roof supports to protect the roof of workings in underground coal mines are discussed. Significant functional effects that can be obtained by using the surface strain hardening of internal surfaces of cylinders of hydraulic actuators are indicated. A device designed for a dynamic method of percussive burnishing of internal cylinder surfaces with the use of a special hydraulic system is presented. The device enables an implementation of high-efficiency surface strain hardening. This treatment makes it possible to improve the resistance of cylinders to fatigue cracks and to harmful tribological phenomena resulting in a leakage of the working medium, affecting the environment negatively. An application of a strengthening device for cylinders enables a more favourable adjustment of hydraulic cylinders for use in extreme working conditions, in particular in the workings threatened by bumping hazards. Besides, the surface plastic deformation also serves to improve usage conditions of high-pressure sealing nodes and it reduces the leakage of water-in-oil emulsion.

Keywords: Hydraulic leg, percussive burnishing

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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