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Anglicky v odbornch pedmtech"Support of teaching technical subjects in EnglishTutorial: Engineering technology

Topic: Friction transmission

Prepared by: Ing. Jaroslav Hbl

Projekt Anglicky v odbornch pedmtech, CZ.1.07/1.3.09/04.0002je spolufinancovn Evropskm socilnm fondem a sttnm rozpotem esk republiky.

FRICTION TRANSMISSIONS

FRICTION TRANSMISSIONSADVANTAGES OF FRICTION TRANSMISSIONQuiet operationIt can have the function of couplingImpacts are absorbed by slippage Little distance of axis at contact gears

FRICTION TRANSMISSIONDISADVANTAGES OF FRICTION GEARSHigh pressure on shafts and bearingsUnevenness of transmission rateEven roll wearing circularity disturbance

FRICTION TRANSMISSIONDISADVANTAGES OF FRICTION GEARSHigh pressure to shafts and bearingsVolatility of gear ratioEven roll wearing circularity disturbance

FRICTION TRANSMISSIONGear ratio

The rule for friction gears by slip effect is:

= slip coeficient

FRICTION TRANSMISSIONBasic 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 TRANSMISSIONMATERIALS OF FRICTION WHEELSQuenched 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 TRANSMISSIONCONSTRUCTIONAL VERSION OF FRICTION WHEELSa) Frontal with lining, b) frontal with layered leather, c) face cast iron wheels, d) face wheels with lining

FRICTION TRANSMISSIONCONSTRUCTIONAL VERSION OF FRICTION WHEELSa) WHEEL WITH LINER, b) WHEEL WITH LEATHER LINING, c) IRON CONICAL WHEEL, d) FRICTION FACE WHEEL WITH DIVIDED THREAD

FRICTION TRANSMISSIONConstructional version of friction wheelsa) Frontal with lining, b) frontal with layered leather, c) face cast iron wheel, d) face wheel with lining

LiteratureStroje a zazen I, J. Doleek, P. Gajdo, V. Novk Strojnictv I, J. Doleek, Z. HoloubekStrojnictv II, J. Doleek, Z. HoloubekModern strojrenstv, 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.