HELICAL AND HELICAL SHAFT MOUNTED GEARMOTORS
Z4
Introduction Helical and helical-shaft mounted gearmotors based on modular assembly system enable the optimal solutions for numerous drives of low speed operating machines which cannot be resolved any more using an electric motor. Modular system enables a great deal of gear alternatives with a minimum of both standard and type components and assemblies the system consists of. All of these gearunits are standardly produced and supplied as helical, helical-shaft mounted or - in combination with el.motors or input assemblies. The gears are distinguished by their simple coupling possibilities with electric motors as gear motors which enable a good alignement of the electric motor shaft and first gear shaft providing a long-lasting and reliable functioning of the gearunits. There is no need for the motor foundation and the compactness is also better. The electrical characteristics of the electric motors intended for gears which are used at motor gears are identical with standard IEC electric motors intended for industrial purposes. Their mechanical characteristics slightly differ from standard IEC electric motors as far as their flange and shaft end coupling dimensions and reinforced bearings are concerned. There is a possibility of mounting IEC motors with a special adapter for IEC motors (up to 200 mm shaft height, I.E. up to 30 kW) with an elastic coupling incorporated. The gearunits can also be supplied without electric motors as motorless gearunits if the subassembly B, BT is fitted to the input side of both helical or shaft-mounted gearunits.
Technical Execution The gearunits′ housings are made of grey iron, they are mechanically and thermally stable and can reduce the vibrations. Their construction is meant for continuous duty. They are determined by the max. output torque. There are two types of executions of the housings: with or without feet. The gears are made of alloyed steel by turning and milling (planing, if necessary). The desired characteristics are obtained by thermal processing and grinding of the surfaces. Cautious manufacturing and permanent control assure high quality and reliability of different stages of transmission (according to standard series R20/3). The gear shafts are produced of plain refined steel distinguished by the best characteristics as to hardness, rigidity and tenacity. The bearings are roller bearings that make the assembly more simple and assure high carrying capacity. Lubrication by splashing oil creates the oil film between the teeth in contact eliminating the metal contact. Besides that, lubricating oil leads the thermal losses onto the housing and protects from corrosion in working and stand-still condition of the gearunit. Tightening, as a very important element when the driving security is concerned, is done by means of both high quality shaft tighteners and tightening caps which prevent the oil leakage and the penetration of the dust into the gearunit. Colouring and antirust protection is standardly performed with a basic colour onto which a finishing layer of RAL 7001 GREY colour is painted. The processed surfaces are protected with a thin antirust coating. It is possible to request some other kind of colouring and protection.
Power, Torque and Speed Values of output power greaded acording to ISO 497/73 and torque values from selection tables refer to the standard execution, standard ambiental conditions and also standard lubrication of gearunits and motor gears. Motor output values given in tables are just orientational ones. In every single case of application the crucial parameter is the output torque at requested output r.p.m. The output r.p.m. values given in tables for the selection of the gearunits are rounded off to the standard values according to R20 series. The real r.p.m. value is attainable from motor rated r.p.m. and gear ratio, and depends on real loading and changes of the network tension.
Efficiency The efficiency is defined mainly by rolling losses of teeth and bedding of the bearings. Depending on the number of stages of the gearunit the efficiency of the basic gearunit is between 94 and 98%. In case of a combination of basic and additional gearunit the efficiency is between 85-92%.
Gear Unit Weight Since the oil quantity depends on mounting position the gearunit masses given in the tables refer to the motor and motorless gearunits without oil filling. The oil masses are given in another table.