Technical data
22
02.00|ROTA NCK plus |en
Calculations for clamping force and speed
Missing information or specifications can be requested from the
manufacturer!
Legend
F
c
Total centrifugal force [N]
M
cAB
Centrifugal torque of top jaws [kgm]
F
sp
Effective clamping force [N]
M
cGB
Centrifugal torque of base jaws [kgm]
F
spmin
Required minimum clamping force
[N]
n
RPM [min
-1
]
F
sp0
Initial clamping force [N]
r
s
Center of gravity radius [m]
F
spz
Machining force [N]
r
sAB
Center of gravity radius of top jaw [m]
m
AB
Mass of one top jaw [kg]
s
sp
Clamping force safety factor
m
B
Mass of clamping jaw set [kg]
s
z
Machining safety factor
M
c
Centrifugal force torque [kgm]
Σ
s
Max. clamping force of the chuck [N]
Calculation of the required clamping force in case of a given rpm
The
initial clamping force F
sp0
is the total force impacting radially
on the workpiece via the jaws due to actuation of the lathe chuck
during shutdown. Under the influence of rotation, the jaw mass
generates an additional centrifugal force. The centrifugal force re-
duces or increases the initial clamping force depending on wheth-
er gripping is from the outside inwards or from the inside out-
wards.
The sum of the initial clamping force
F
sp0
and the
total centrifugal
force F
c
is
the effective clamping force F
sp
.
6.3
6.3.1