SCHUNK ROTA TP Series - Calculation of the Permissible Speed in Case of a Given Initial Clamping Force

Technical data
04.00|0889071 ROTA TP / ROTA TP-LH |en
25
CAUTION
For safety reasons, in accordance with DIN EN 1550, the
centrifugal force may be a maximum of 67% of the initial
clamping force.
The formula for the calculation of the total centrifugal force F
c
is:
For this, n is the given speed of rotation in RPM. The product m
B
∙
r
s
is referred to as the centrifugal torque M
c
.
In case of toolholders with split chuck jaws, i.e., with base jaws and
top jaws, for which the base jaws change their radial position only
by the stroke amount, the centrifugal torque of the base jaws
M
cGB
and the centrifugal torque of the top jaws M
cAB
need to be
added:
The centrifugal torque of the base jaws M
cGB
can be found in the
table "Lathe chuck data"( 3.1, Page 18). The centrifugal torque
of the top jaws M
cAB
is calculated as per:
Calculation example: required initial clamping force for a given
speed
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 RPM (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.
3.3.2