Below
are some of the frequently asked questions that may help you with the
parvalux products, should you need any further information please
contact our sales team. Tel: (011) 622-6826
What is axial load ?
What is radial load ?
Can more than one motor be operated from a single control ?
Which gearheads are self-locking ?
What is meant by the term self-locking ?
What is IP 54 ?
Is an adjustable speed system ever appropriate for a single speed application ?
Can single speed motors and gearmotors ever be operated as variable speed ?
Can continuous duty motors/gearmotors be used intermittently ?
Which motors/gearmotors are electrically reversible ?
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What is axial load ?
Axial
load is a force on the output shaft into or out of the motor or
gearmotor. It is shown as Fa in the diagram above. Exceeding the
allowable axial load for a motor or gearmotor will cause premature wear
on output shaft bearings and gearing. |
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What is radial load ?
Radial
load is a force pushing or pulling the side of the output shaft. It is
shown as Fr above. Exceeding the allowable radial load for a motor or
gearmotor will cause premature wear of output shaft bearings and
gearing and could cause the shaft to break. Fr may be the result of a
weight on the shaft, belt tension or torque transmitted through a belt,
chain, gear, or certain flexible couplings. A permissible radial load
(Fr) is shown for each motor and gearmotor. In calculating these
values, the following assumptions were made:
- The radial load is the worst case direction, i.e. pushing or pulling the shaft sideways.
- The motor or gearmotor is delivering rated torque.
- The
radial load was applied at distance "d" from the hub or mounting
surface. Higher radial loads may be applied closer in on the shaft.
Lower radial loads are permitted further out on the shaft.
Flexible
couplings are often used to avoid radial load. Most flexible couplings
are designed so that they do not transmit radial load, however this
should be verified with the coupling manufacturer. |
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Can more than one motor be operated from a single control ?
Operation
of more than one motor from a single control is not normally
recommended. However, when the cost is a primary concern, a multiple
motor/single control system with either permanent magnet motors and
control, or 3 phase motors and control, may be successfully implemented.
More than one permanent magnet motor may be operated with a single
permanent magnet control as long as the sum of the motor currents does
not exceed the rated output current of the controller.
Comprehensive testing is
recommended because this type of system may produce fluctuation or
drifting speed output. More than one three phase motor may be operated
with a single three phase control. Motor speeds should not fluctuate as
long as the motors are not overloaded and the sum of the motor currents
does not exceed the rated output current control. |
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Which gearheads are self-locking ?
Parrallel
shift gearheads and right angle gearheads with low ratios are generally
not considered to be "Self-locking". Right angle gearheads with ratios
greater than 25:1 are often considered to be "Self-locking". They will
resist movement up to their torque rating. As the gearing nears the end
of its useful life or it is subjected to overload conditions, it may
wear to the point where it is no longer "Self-locking". Self-locking
gearing is not a recommended method for preventing movement in
applications where the movement may cause injury or damage. An external
brake is recommended for those applications. |
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What is meant by the term self-locking ?
Self-locking
refers to the tendency of some gearing to resist movement when the
gearmotor is at rest and the load is attempting to move. An example of
this is a load on a conveyer belt trying to drive the system backwards. |
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What is IP 54 ?
The IP number is an international system for rating enclosures. An IP 54 is for protection against dust and splashing liquids. |
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Is an adjustable speed system ever appropriate for a single speed application ?
Adjustable
speed systems are sometimes appropriate for single speed applications.
If the desired speed is not known or offered in a single speed product,
an adjustable speed system may be set to a desired speed. |
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Can single speed motors and gearmotors ever be operated as variable speed ?
Three
phase and some Permanent Split Capacitor designs may be operated as
variable speed with our frequency inverter. Commutator motors can be
operated as variable speed using a thyristor controller. |
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Can continuous duty motors/gearmotors be used intermittently ?
All
rated torques shown in this catalogue are for continuous operation.
Continuous duty products can be used intermittently. Operation at loads
higher than the nameplate ratings is possible for short periods as long
as there are rest periods for cooling. Loads must not exceed the
mechanical rating for the gears without consulting our sales engineers.
The temperature of the motor should be monitored during testing to make
sure it is not overheating. |
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Which motors/gearmotors are electrically reversible ?
All motors and gearmotors in this catalogue are reversible. (except shaded pole). Some require a full stop before reversing. |
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