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Anglicky v odborných předmětech "Support of teaching technical subjects in English “. Tutorial : Engineering technology Topic : Slide bearings Prepared by: Ing. Jaroslav Hábl. Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002
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Anglicky v odborných předmětech"Support ofteachingtechnicalsubjects in English“ Tutorial: Engineering technology Topic:Slide bearings Prepared by: Ing. Jaroslav Hábl Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.
Bearing is a part of a machine enabling components connection and secures their relative motion ( either rotary or sliding one). If surfaces of touching parts move mutually, friction is created between them. This friction becomes evident by friction force and/or friction moment. It is necessary to reduce friction as much as is possible because friction causes lower efficiency, components heating and wearing off. That is why friction surfaces are separated by the coat of lubrication. SLIDE BEARINGS
Dry friction • Mixed friction – occasional contact of tops of uneven parts • Liquid friction – individual parts are permanently separated by lubricant - liquid - gaseous SLIDE BEARINGSTYPES OF FRICTION IN CONTACT AREAS
Liquid friction is made: a) By pumping areas effect making wedge-shaped lubrication layer. It shows at speeds over 0,5 ms-1 and is called hydrodynamic lubricant. b) Hydrostatic lubricant pressureis conveyed by pump (pressure oil). SLIDE BEARINGS
SLIDE BEARINGS Hydrodynamic friction a) Static pivot, b) rotating pivot, c) pivot position at high speed
Advantages of slide bearings • Accuracy • Very high efficiency (due to of areal contact) • Quiet operation • Absorbs shocks • Durability • Small dimensional demand SLIDE BEARINGS
Disadvantages of slide bearings • Friction depends on process speed • More difficult part change • High demand on lubrication • Incomplete standardization SLIDE BEARINGS
CONSTRUCTION OF SLIDE BEARINGS SLIDE BEARINGS Without lining With lining
CONSTRUCTION OF SLIDE BEARINGS SLIDE BEARINGS Ball axle box
CONSTRUCTION OF SLIDE BEARINGS Step thrust bearing with a pressure distribution SLIDE BEARINGS
Literature • Stroje a zařízení I, J. Doleček, P. Gajdoš, V. Novák • Strojnictví I, J. Doleček, Z. Holoubek • Strojnictví II, J. Doleček, Z. Holoubek • Moderní strojírenství, Josef Dilinger a kolektiv
Define the word ´bearing´. • Types of friction in contact areas do you know? • Draw slide bearing with lining.