THE STUDY OF THE PROCES OF HOBBING OF WORM GEAR SHAVER LATERAL SURFACES

Worm gear shavers are used for finishing hob gears. The incisions on the lateral surfaces can be rectilinear (they are obtained by grooving at point blank range - their manufacture is labour-consuming, it is impossible to finish the gear tooth with a special profile in the conditions of individual production), have a curvilinear shape (hypocycloid), and also be made in the form of a system of holes (utility model patent No. 102111). According to the design of the worm gear shaver under study (utility model patent No. 38125 [1]), clearance grooves of a hypocycloid shape are cut on lateral surfaces. The shape of the incisions is due to the continuity of the generating process. Clearance grooves of this shape can be cut using vertical turning mills with end cutter, but in this case the grooves vary in depth and ‘undercutting’ or ‘cutting’ of the edge can occur. Using CNC machines, it is possible to cut the grooves more accurately with end cutter. For cutting the grooves of the hypocycloidal shape, the following equipment was used: Fanuc Robodrill α-T21i machine with a Nikken rotary table, an end five-tooth milling cutter. Processing takes place due to the mutually controlled motion of the cutter and of the workpiece. The processing of the worm gear is carried out applying standard technology. The are no recommendations concerning the choice of the geometric parameters of the grooves, therefore a worm gear m = 10 was used for modelling worm gear shaver and for designing grooves cutting and the parameters of the worm gear shaver were taken from [2]. When cutting grooves using a СТС machine, it is possible to avoid inaccuracy in edges but a facetting occurs. When examining the size of facetting of the grooves of the worm gear shaver, it can be determined using the same technique applied when determining the facetting when processing the involute of the gear wheel. To study the faceting there was a need its mathematical definition. Based on the provisions of differential geometry, formulas for faceting calculation were derived.

червячный шевер, параметры, стружечные канавки, концевые фрезы, обработка, огранка, насечки, worm gear shaver, parameters, clearance grooves, end cutter, processing, facetting, grooves

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