7applications – Lenze DSD User Manual
Page 102
7
Applications
7.6
Spindle drive
102
Lenze · Drive Solution Designer · Manual · DMS 4.2 EN · 12/2013 · TD23
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Additionally a force F
vs
can act, e. g. a force due to weight during a slope of the linear movement.
• F
vs
is an external counterforce that can act additionally on the slide or the rack and pinion. The
direction of the force is to be observed.
[7-59] Equation 9: Total translatory force
Required torque of the application
The required torque of the application M
App
has to be calculated in three steps. First the force that
is transmitted via the rack and pinion has to be ascertained:
[7-60] Equation 10: Force of the slide on the spindle
The friction force depends on the force F
App
to be transmitted, so that the resulting force that is
transmitted via the spindle is calculated by means of the following equation.
• It is assumed that η is the leadscrew efficiency in motor mode. The deterioration of the efficien-
cy for operation in generator mode (backward efficiency) is taken into consideration during this
calculation.
[7-61] Equation 11: Force transmitted to the slide, taking the spindle friction into consideration
Consideration of axial forces
In the case of rack and pinions with helical teeth, there are axial forces resulting in a stress for the
shaft bearings on the gearbox output end or on the motor.
The DSD does not calculate axial forces. You have to check them separately and take them into con-
sideration during the dimensioning process.
Torque
For calculating the required torque of the application, the additional moments of inertia (e. g. that
of the spindle) are to be taken into consideration.
[7-62] Equation 13: Required torque of the application
Tip!
Further equations to complete the calculations required for an application can be found in
the chapter "
".
F
sum
F
vs
m
+
sum
g
β
sin
⋅ ⋅
=
F
App
F
sum
F
μ
+
(
) m
+
sum
a
⋅
=
F
App,η
F
App
F
App
v
v
-----
1
η
Spl
----------
1
–
⋅
⋅
+
=
M
App
r
Res
F
App,η
⋅
J
add
α
⋅
+
=