Gear drives Press crow n assembly

3.2.6 Gear drives

In co n t rast t o blan kin g p resses, wh o se co n t in u o u s st ro kin g rat e co r- resp on d s to th e sp eed of th e flywh eel, p resses with on e or two-stage red u cin g wh eel gears are u sed for lon ger workin g strokes. In large-p an el p resses, t h e co n n ect in g ro d an d lin ks are gen erally d riven by a t wo - st age red u ct io n gear. Dep en d in g o n t h e n ecessary p o wer d ist ribu t io n o ver t wo , fo u r o r, in t h e case o f t ran sfer p resses, u p t o t welve co n n ect - in g ro d s, t h e gear u n it s wit h wh eels an d lin ks fo rm t h e n erve cen t er o f m o d ern p resses. Eccen t ric wh eels wit h a d iam et er o f u p t o 3,000 m m an d red u cin g gears o f u p t o 1,600 m m in d iam et er are m an u fact u red fro m h igh - st ren gt h d u ct ile iro n cf. Sect . 3.7 . Th e gear t eet h o n t h e sh aft s an d p in io n s are h ard en ed . Do u ble h elical gearin g gu aran t ees o p t im u m p o wer t ran sm issio n an d lo w ru n n in g n o ise Fig. 3.2.4 . Th e gears an d q u ill p in io n sh aft s are m o u n t ed o n flo at in g axles wit h frict io n bearin g bu sh in g fo r easy assem bly. At t h e st art o f t h e p o wer t rain is always t h e d rive sh aft wit h d rive p in io n , clu t ch an d brake. Un like o t h er gear d ri- ves, ro ller bearin gs are u sed in t h e sp eed ran ge fro m 300 t o 500 rp m . 65 M echanical presses Fig. 3.2.9 Drive system of a transfer press w ith crossbar transfer Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998

3.2.7 Press crow n assembly

Th e co n n ect in g ro d , lin ks, gears an d m ain d rive syst em d et erm in e t h e cap acit y an d t h e size o f t h e p ress cro wn . Th e weld ed co m p o n en t s weigh u p t o 150 t , as d o t h e m o u n t ed gear d rive elem en t s co n t ain ed in t h e cro wn o f a large-p an el p ress. Th e d im en sio n al lim it s o f su ch large-scale p art s are aro u n d 6,000 3 3,600 3 12,000 m m , wh ereby wid t h , h eigh t an d weigh t d ep en d o n t h e p o ssibilit ies o ffered fo r ro ad t ran sp o rt o n lo w-bed t ru cks – wh ich gen - erally req u ire sp ecial au t h o rizat io n . Wat erways rep resen t a less d ifficu lt m et h o d o f t ran sp o rt in g t h is t yp e o f co m p o n en t s. St ress-relief an n ealin g o f large weld ed assem blies an d also m ach in in g on d rillin g cen ters is restricted to a m axim u m len gth of 12 m . Th e en tire p ro blem o f t ran sp o rt lo gist ics p lays a m ajo r ro le in large-p an el p ress d esign an d m u st be t aken in t o co n sid erat io n righ t fro m t h e p lan n in g st age.

3.2.8 Slide and blank holder