TOS SUA 125 NUMERIC, Operating Instructions Manual

Page: 115 / 118

SUA 125 NUMERIC
34200003 TOS a.s. 02/2011
115
16. Determination of the torque moment Mk for the given cutting conditions
according to the motor output
This Instruction Manual and further accompanying documentation (Control System Instruction Manual, Software Book,
Protocol on Accuracy) supplied with the machine have been focused to a safe, hygienic and ecological operation of the
lathe.
The following example as well as the table charts and diagram create the informative underlying document for the use of the
installed output in dependence with the kind of material and its machinability.
Example:
Motor output of the machine
P=30 kW
Material steel, strength 60 kp/mm
2
(600 MPa)
Dia. to be machined D=500 mm
Chip depth h=10 mm
Feed s=0.5 mm/rev
Cutting speed v=150 m/min
Calculation of the maximum torque moment for the given cutting conditions:
. rev 5 . 95
500
150 1000
D
v 1000
n
1000
n D
v
=
 

=
 

= 
  
=
Of the diagram (Outputs and torque moments at the spindle - Pict. 3.3) there can be read-off, according to the revolutions,
the maximum torque moment M
k max
M
k max
= 3000 N.m
Calculation of the real torque moment M
k
of the cutting force
F=S
t
. k
s
= 5 . 1550 = 7750 N
Of the table chart 8 there can be found, according to material, the specific cutting resistance k
s
k
s
= 1550 N/mm
2
S
t
= h . s = 10 . 0.5 = 5 mm
2
Mk = F . R = 7750 . 0.25 = 1937.5 N.m
M
k max

M
k

Output of the motor is sufficient
This is an informative calculation, it does not include the effect of the tool.
Remark: Tab. 9 - Cast iron