IMS MDrive34Plus, Руководство по эксплуатации продукта

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A-8
MDrive 34Plus Microstepping Hardware - Revision R071108
Relevant to Firmware Version 3.0.02
Shock Load Output Torque
The nominal output torque (T
N
) is the actual working torque the Planetary Gearbox will generate. The shock
load output torque (T
AB
) is the additional torque that can be generated by starting and stopping with no
acceleration ramps, payloads, inertia and directional changes. Although the nominal output torque (T
N
) of
the Planetary Gearbox is accurately calculated, shock loads can greatly increase the dynamic torque on the
Planetary Gearbox.
Each Planetary Gearbox has a maximum specified output torque. In this example a 7:1 single stage MD23
Planetary Gearbox is being used. The maximum specified output torque is 566 oz-in. By calculating the shock
load output torque (T
AB
) you can verify that value is not exceeding the maximum specified output torque.
When calculating the shock load output torque (T
AB
), the calculated nominal output torque (T
N
) and the
operating factor (C
B
) are taken into account. C
B
is merely a factor which addresses the different working
conditions of a Planetary Gearbox and is the result of your subjective appraisal. It is therefore only meant as a
guide value. The following factors are included in the approximate estimation of the operating factor (C
B
):

Direction of rotation (constant or alternating)

Load (shocks)

Daily operating time
Note: The higher the operating factor (C
B
), the closer the shock load output torque (T
AB
) will be to the maxi-
mum specified output torque for the Planetary Gearbox. Refer to the table below to calculate the approximate
operating factor (C
B
).
With the most extreme conditions which would be a C
B
of 1.9, the shock load output torque (T
AB
) is over the
maximum specified torque of the Planetary Gearbox with a 0.5 safety factor but under with a 0.7 safety factor.
The nominal output torque (T
N
)
×
the operating factor (C
B
) = shock load or maximum output torque (T
AB
).
With a 0.5 safety factor, the shock load output torque is greater than the maximum output torque specifica-
tion of the MDrive23 Planetary Gearbox.
(378
×
1.9 = 718.2 oz-in.)
With a 0.7 safety factor the shock load output torque is within maximum output torque specification of the
MDrive23 Planetary Gearbox.
(270
×
1.9 = 513 oz-in.)
The 0.5 safety factor could only be used with a lower operating factor (C
B
) such as 1.5 or less, or a lower mo-
tor torque.
Note: All published torque specifications are based on C
B
= 1.0. Therefore, the shock load output torque
(T
AB
) = nominal output torque (T
N
).
WARNING! Excessive torque may damage your Planetary Gearbox. If the MDrive/Planetary Gearbox should
hit an obstruction, especially at lower speeds (300 RPM or 1000 Full Steps/Second), the torque generated
will exceed the maximum torque for the Planetary Gearbox. Precautions must be taken to ensure there are no
obstructions in the system.
Determining the Operating Factor (C
B
)
Direction of
Rotation
Load
(Shocks)
Daily Operating Time
3 Hours 8 Hours 24 Hours
Constant Low* C
B
=1.0 C
B
=1.1 C
B
=1.3
Medium** C
B
=1.2 C
B
=1.3 C
B
=1.5
Alternating Low† C
B
=1.3 C
B
=1.4 C
B
=1.6
Medium†† C
B
=1.6 C
B
=1.7 C
B
=1.9
* Low Shock = Motor turns in one direction and has ramp up at start.
** Medium Shock = Motor turns in one direction and has no ramp up at start.
† Low Shock = Motor turns in both directions and has ramp up at start.
†† Medium Shock = Motor turns in both directions and has no ramp up at start.
Table B.1: Planetary Gearbox Operating Factor