wit h a lo n g service life an d lo w m ain t en an ce co st s Fig. 3.2.8
. Th e elec- t ric m o t o r d rives t h e eccen t ric sh aft by m ean s o f a flywh eel, a clu t ch -
brake co m bin at io n t h at can be eit h er h yd rau lically o r p n eu m at ically act u at ed an d a h igh -p erfo rm an ce p lan et ary gear cf.
Fig. 4.4.4 . Th is
elim in at es t h e n eed fo r t h e red u cin g gear gen erally req u ired fo r u n iver- sal p resses. Co m p act d rive syst em s u sin g a h yd rau lic clu t ch -brake co m -
bin at io n are p art icu larly en viro n m en t ally frien d ly, as t h ey p ro d u ce n o abrad ed p art icles an d ru n at an ext rem ely lo w n o ise level.
3.2.5 Longitudinal and transverse shaft drive
Th e d esign of a m ech an ical p ress is d eterm in ed m ain ly by th e arran ge- m en t of th e d rive sh afts an d axles, an d by th e n u m ber of p ressu re p oin ts
of th e con n ectin g rod on th e slid e cf. Fig. 3.1.3
. Th e term lon gitu d in al or tran sverse sh aft d rive is d efin ed by th e arran gem en t of th e d rive
sh afts relative to th e fron t of th e p ress, wh ere th e p ress op erator stan d s.
63
M echanical presses
clutch-brake disks
flyw heel planetary gears
eccentric shaft
Fig. 3.2.8 Compact drive
system used in a universal press
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
Longitudinal shaft drive is u sed m ain ly in sin gle-act in g o n e- an d t wo - p o in t p resses wit h eccen t ric d rive syst em s cf.
Fig. 4.4.4 an d
4.6.29 .
Th ese are gen erally blan kin g p resses an d u n iversal p resses in t h e lo wer fo rce ran ge o f u p t o 8,000 kN. Th is classical d rive arran gem en t is also
u sed in lo n g an d n arro w t ran sfer p resses wh ere bet ween t wo an d six p ressu re p o in t s o r co n n ect in g ro d s are lo cat ed in t h e lo n git u d in al d irec-
t io n . Th e co n n ect in g ro d s are d riven by a co n t in u o u s d rive sh aft . Th e t ran sfer p resses are d esign ed wit h n o m in al p ressin g fo rces bet ween
1,000 an d 35,000 kN. Th ey h ave u p t o fo u r p airs o f u p righ t s an d t h ree slid es cf.
Sect . 4.4.6 .
Th e co n n ect in g ro d s are arran ged in t h e area o f t h e u p righ t s an d t ie ro d s wit h t h e p u rp o se o f m in im izin g t h e ben d in g st ress o n t h e p ress
cro wn . Th is leaves t h e t o p o f t h e wo rk st at io n s in t h e slid e free fo r ejec- t io n fu n ct io n s. Fo r sim p ler p ro d u ct io n an d assem bly, in larger-scale
t ran sfer p resses, t h e lo n git u d in al sh aft d rive is also rep laced by a t ran s- verse sh aft d rive syst em . Kn u ckle-jo in t p resses wit h sin gle-p o in t d rive,
co verin g a fo rce ran ge fro m 1,500 t o 16,000 kN rep resen t an o t h er sp e- cial co n st ru ct io n .
Th e transverse shaft press is d esign ed t o h ave o n e-, t wo - o r fo u r-p o in t co n n ect io n s an d p ressin g fo rces o f bet ween 1,600 an d 20,000 kN. Th is
d esign p erm it s a great er bed d ep t h , a lo n ger st ro ke an d also t h e u se o f a jo in t syst em . Do u ble-act in g d eep d rawin g p resses are o n ly available in
t h is co n figu rat io n Fig. 3.2.4
. Large-p an el p resses wit h t ri-axis t ran sfer in a ran ge fro m 18,000 kN t o
45,000 kN p ress fo rce are also based o n a t ran sverse sh aft d rive syst em cf.
Sect. 4.4.7 . To p erm it th e d istribu tion of p ressin g forces – gen erally
o ver fo u r co n n ect in g ro d s p er slid e – ext en sive gear u n it s are req u ired wh ich are acco m m o d at ed in m u lt ip le-walled p ress cro wn s. Th u s, t h e
gear d rive syst em s are sim p lified an d im p ro ved . Th e lat est d evelo p m en t in t h e field o f large-p an el p resses is t h e
cro ssbar t ran sfer p ress. It s fu n ct io n s in clu d e t h e p ro d u ct io n o f p as- sen ger car sid e p an els in d ies m easu rin g u p t o 5,000 3 2,600 m m
cf. Sect . 4.4.8
. In a five-st age co n figu rat io n , five t ran sverse sh aft d rive u n it s are jo in ed t o fo rm a m ach in e assem bly sim ilar t o a p ress
lin e, an d all six d rive sh aft s co n n ect ed by clu t ch es Fig. 3.2.9
. Th is t ran sfo rm s t h e co m p let e p ress in t o a lo n git u d in al sh aft d rive o ffer-
in g all t h e ad van t ages o f a t ran sverse sh aft d rive.
64
Fundamentals of press design
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
3.2.6 Gear drives
