Technical data
22
04.00 | | Jaw boxes SPK | en | 0889015
6.2.2 Calculation example: Required initial clamping force Fsp0 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. speed of rotation n
max
= 3200 RPM (Table "Permissible
speed of rotation for jaw boxes on face plates"
)
• 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:
Calculated centrifugal moments of the base jaw and the top jaw:
For the centrifugal torque of the top jaw, the following applies:
Centrifugal torque for one jaw:
The clamping jaw boxes have 3 jaws, the total centrifugal moment
is:
