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Combinazioni serie MKF + MU Combined units of the series MKF + ...

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Tabella prestazioni riduttori combinatiE’ opportuno fare presente che, nel caso dei riduttoricombinati motorizzati, numerose motorizzazioni indicatenella tabella darebbero luogo a fattori di servizio particolarmentebassi. Ciò deriva dal fatto che, essendo ilrapporto di riduzione particolarmente elevato e quindila velocità in uscita molto bassa, mentre la coppia sieleva percentualmente di poco rispetto al riduttore semplice,i riduttori combinati richiedono potenze estremamentebasse per non superare la coppia di uscita massimaammessa, spesso non compatibili con lemotorizzazioni esistenti o con le predisposizioni PAMpreviste per il primo riduttore.E’ quindi pratica comune utilizzare sui combinati motorizzativalori di potenza in entrata estremamente elevatirispetto a quelli che corrisponderebbero alla massimacoppia ammissibile.In tutti questi casi, è indispensabile accertarsi chela coppia effettiva richiesta dall’applicazione nonsuperi quella massima ammessa dal riduttore: indicatanelle tabelle come M 2max.Performance tables <strong>of</strong> combined gearboxesIt is convenient to point out that, in <strong>the</strong> case <strong>of</strong>wormgearboxes with motor, several kinds <strong>of</strong> motor sizesappearing in <strong>the</strong> performance tables would give rise toextremely low service factors. This comes from <strong>the</strong>consideration that, being <strong>the</strong> reduction ratio usuallyextremely high in <strong>the</strong> combined <strong>units</strong>, and thus <strong>the</strong> outputspeed extremely low, while <strong>the</strong> output torque suffers apercentually much smaller increase, if compared with <strong>the</strong>single gearbox, <strong>the</strong> combined <strong>units</strong> would require anextremely low input power for not exceeding <strong>the</strong> max.permissible output torque; this is <strong>of</strong>ten uncompatible with<strong>the</strong> existing motor sizes, or with <strong>the</strong> motorprearrangements(PAM) provided on <strong>the</strong> first unit.It is <strong>the</strong>refore a common practice to use on <strong>the</strong> combined<strong>units</strong> with motor values <strong>of</strong> input power extremely high ifcompared with <strong>the</strong> ones which would correspond to <strong>the</strong>max. allowable output torque.In all <strong>the</strong>se cases, it is extremely important to makesure that <strong>the</strong> effective output torque requested by <strong>the</strong>application does not exceed <strong>the</strong> max. allowable oneby <strong>the</strong> wormgearboxe with motor: shown on <strong>the</strong> tablesas M 2max.2

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