Screw tightening torques
30
02.00|1416054_ROTA-M2 + 2 |en-US
Calculation example: required initial clamping force for a given
RPM
Required initial clamping force F
sp0
for a given RPM n
The following data is known for the machining job:
•
Gripping from the outside in (application-specific)
•
Machining force F
spz
= 3000 N (application-specific)
•
max. RPM n
max
= 3200 RPM ("Lathe chuck data" table)
•
RPM n = 1200 min
-1
(application-specific)
•
Mass of one (!) top jaw m
AB
= 5.33 kg (application-
specific)
•
Center of gravity radius of top jaw r
sAB
= 0.107 m (application-
specific)
•
Safety factor S
z
= 1.5 (according to VDI 3106)
•
Safety factor S
sp
= 1.5 (according to VDI 3106)
Note:
Masses of the jaw mounting screws and T-nuts are not taken
into account.
First the required effective clamping force F
sp
is calculated using
the machining force stated:
Initial clamping force during shutdown:
Calculation of total centrifugal force:
For two-part chuck jaws, the following applies:
Take the centrifugal torque of the base jaw and top jaw specified
from the "Lathe chuck data" table:
For the centrifugal torque of the top jaw, the following applies:
Centrifugal torque for one jaw:
The chuck has 3 jaws, the total centrifugal torque is:
3.4.2
