Lubrication M echanical presses .1 Determination of characteristic data

Th is req u ires sep arat e su p p ly u n it s wit h o il t an k, p u m p o u t p u t s o f ap p ro x. 150 kW an d o il flo w rat es o f ap p ro x. 1,000 l m in fo r t h e d raw cu sh io n . Co n t ro l is p erfo rm ed u sin g p ro p o rt io n al valves co m p lyin g t o DIN an d ISO st an d ard s in t h e p ressu re ran ge u p t o 300 bar.

3.2.11 Lubrication

Th e co m p lex lu bricat io n syst em s u sed t o su p p ly t h e lu bricat io n p o in t s in m ech an ical p resses are su bst an t ially sim p lified by u sin g valve blo cks cf. Fig. 3.3.4 . Th e syst em m o st co m m o n ly u sed h ere co n sist s o f p aral- lel-swit ch in g p ro gressive d ist ribu t o rs. Allo cat io n o f t h e req u ired q u an - t it y o f lu brican t is aid ed by vo lu m e co n t ro llers, d ivid ers an d sim ilar ele- m en t s. Th e flo w o f o il is m o n it o red at t h e d ist ribu t o r blo cks. To en su re o p t im u m o p erat in g co n d it io n s, a co n t ro l syst em regu lat es t h e t em p er- at u re o f t h e lu brican t wit h in a relat ively n arro w ban d wid t h by u sin g au xiliary h eat in g an d co o lin g fu n ct io n s. To gu aran t ee m axim u m o p erat in g safet y, co m p lex p ro d u ct io n in st al- lat io n s fo r m et al fo rm in g are always fit t ed wit h t win su p p ly u n it ele- m en t s su ch as p u m p s an d filt ers. If o n e p u m p fails, t h ere is n o n eed t o in t erru p t p ro d u ct io n , as t h e seco n d syst em cu t s in au t o m at ically. Main t en an ce o r exch an ge o f t h e d efect ive syst em d o es n o t resu lt in p ro d u ct io n st an d st ill, in creasin g u p t im e. Th e q u alit y o f t h e o il is safe- gu ard ed by su p p lem en t ary filt rat io n in t h e seco n d ary circu it , in creas- in g it s service life. In sm aller p resses, an d in p art icu lar by kn u ckle-jo in t p resses wit h bo t t o m d rive, cen t ral lu bricat io n syst em s wit h m u lt ip le-circu it geared p u m p s are u sed . Up t o 20 m ain lu bricat io n p o in t s are co n t in u o u sly su p p lied d irect ly by t h e gear st ages wit h a co n st an t su p p ly o f o il. Du rin g t h e sh o rt swivel m o vem en t s execu t ed by t h e t h ru st elem en t s an d jo in t s, a co n st an t flo w o f lu brican t is available even u n d er varyin g resist an ce levels in t h e in d ivid u al u ser an d su p p ly lin es. 72 Fundamentals of press design Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 3 Fundamentals of press design 3.3 Hydraulic presses 3.3.1 Drive system