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Anglicky v odborných předmětech "Support of teaching technical subjects in English “. Tutorial : Engineering technology Topic : Friction transmission 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: Friction transmission 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.
ADVANTAGES OF FRICTION TRANSMISSION • Quiet operation • It can have the function of coupling • Impacts are absorbed by slippage • Little distance of axis at contact gears FRICTION TRANSMISSIONS
DISADVANTAGES OF FRICTION GEARS • High pressure on shafts and bearings • Unevenness of transmission rate • Even roll wearing – circularity disturbance FRICTION TRANSMISSION
DISADVANTAGES OF FRICTION GEARS • High pressure to shafts and bearings • Volatility of gear ratio • Even roll wearing – circularity disturbance FRICTION TRANSMISSION
Gear ratio The rule for friction gears by slip effect is: ψ = slip coeficient FRICTION TRANSMISSION
Basic types of friction contact gears a b c d e f a) Outside gearing, b) inside gearing, c) outside gear with keyway, d) inside gear with keyway, e) conical bearing, f) gear with face wheels FRICTION TRANSMISSION
MATERIALS OF FRICTION WHEELS • Quenched steel x quenched steel – higher pressure force enables higher load transmission, • Longer durability. • Rubber x steel or cast iron – gearing has quiet operation, it transmits cca 10x smaller loading. • Other materials x steel or cast iron – e.g. Fibre, plastics etc. • Non-metallic materials are mostly used as metallic wheels lining. FRICTION TRANSMISSION
CONSTRUCTIONAL VERSION OF FRICTION WHEELS FRICTION TRANSMISSION a) Frontal with lining, b) frontal with layered leather, c) face cast iron wheels, d) face wheels with lining
CONSTRUCTIONAL VERSION OF FRICTION WHEELS FRICTION TRANSMISSION a) WHEEL WITH LINER, b) WHEEL WITH LEATHER LINING, c) IRON CONICAL WHEEL, d) FRICTION FACE WHEEL WITH DIVIDED THREAD
Constructional version of friction wheels FRICTION TRANSMISSION a) Frontal with lining, b) frontal with layered leather, c) face cast iron wheel, d) face wheel with lining
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
What are the advantages of friction wheels? • What materials are used for friction wheel construction? • Name at least 3 types of transmission by contact wheels.