- single phase 1 - 90W - single phase, quick reversible and brake motors
- three phase 25 - 90W
- variable speed packages 5 - 90W.
With a very unique and sophisticated technology Panasonic has achieved an
acoustic noise reduction of 15db (compared to equal on the market products), this is a
combination of the application of special helical gears, oil sealed grease structure and
O-rings.
Panasonic has managed to strengthen the gear and bearing material as well as
the gear module 2940N-Cm shaft torque (S-type) for the 90mm square size.
MTBF - 5000 hours guarantee using ball bearings with completely closed gear
box.
The well-known quality and design of Panasonic geared motors internationally,
has transformed them into the preferred motor and drive (in most countries), for
applications where security, excellent MTBF are required, and breakdowns are to be held to
a minimum.
Panasonic's wide selection range of, single-phase or three-phase voltage
supply, break, speed control, quick direction reversal, and high torque, in a small
package, make the search for the ideal induction motion control drive system your best
choice.
Some features: Continuous Ratings - B Class Insulation - High Efficiency Low
Noise - Instant Reverse Rotation - Small over run (< 10% of starting torque) - 30 min.
Ratings - Added options - Dust/Water drop protection - Terminal box - Sealed connector for
conduit.
Variable speed motors suits DVUS and DVSD controllers
( See The Speed Controls
Pages)
The Panasonic single phase variable speed geared motors operate using closed loop
tach-feedback. The tach, located at the rear of the motor, generates an AC voltage which
is proportional to the motor’s actual speed. This voltage is then compared with the
speed reference signal determined by the operator. This signal is then used to control the
operation of the power device which supplies the voltage and current to the motor
windings.
Standard induction motors
Quick reversible motors
Brake motors
single phase
models for 115V supply
(220-240V supply)
three phase models for either
400V
(380-415V) or 230V (220-240V) supply
continuous rating S1, thermally
protected
class E insulation
built-in constant
friction braking feature
reduced overrun and fast stopping
ideal for quick reversing
UL versions available on request
spring applied
electro-magnetic brake
offers excellent static holding torque at
power off enhanced dynamic stopping
performance
Quick Reversible Motors
A friction plate attached to the end of the
rotor is constantly under friction via four cylindrical brake pads and springs. The
resulting braking torque is continuously applied to the motor even during motor running.
Some models have an S2 intermittent duty rating. Please refer to Data sheets for further
details.
Brake Motors
The brake is released by applying a
voltage to the coil which attracts the armature against the springs. This creates a gap
and frees the brake lining, allowing the
motor shaft to rotate. When the voltage to the coil is
removed, the armature is forced back by the springs against the brake lining, stopping the
motor.
Motor overrun is nominally 2-4 revolutions
and is rated for 6 stop/start operations per minute.
Thermal protection
The 6W motors offer thermal protection by
means of impedance current limiting. All other motors have a thermal protection switch
which should be externally
connected to the machine’s start/stop circuitry for
safety reasons. This will operate at a temperature of 120șC.
The motor will not restart until the temperature
has fallen below 80șC and the machine’s start/stop circuitry has been re-energised.
Let's discuss how the AC induction motor rotates, which involves the
interaction of magnetic fields of the rotor and stator. For this type of motor, the stator
has windings usually connected to the supply in one or three phase form. By applying a
voltage across the winding a radial rotating magnetic field is formed. The rotor typically
looks similar to a squirrel cage, which gives the AC induction motor one of its nick
names, 'the squirrel cage motor', if non-living things are capable of nick names. The
shape of the rotor forms conductive loops throughout its circumference. The stator has two
effects on the rotor. First it induces currents into the conductive loops. Once that is
complete, the magnetic field produces forces on
the current carrying conductors, which results in a torque on the rotor.
The beauty and simplicity of the AC induction motor is that the currents in the rotor does
not have to be supplied by commentation like in a DC motor. But what we are interested in
here are the results. The velocity of the rotating magnetic field of the stator can be
calculated with the formula below:
V=120f / p
Where p is the number of poles and f is the frequency. The induction motor has an inherent
function called slip. Slip quantifies the slower speed of the rotor in comparison with the
magnetic field. The rotor is not locked into any position and therefore will continue to
slip through out the motion. The amount of slip increases proportionally with increases in
load, thus if you need accurate velocity profiles, open loop induction motors are not the
way to go.
AC Induction motors have ruled the turning job, for quite some time in industrial
applications where precise speed control has not been that important, such as pumps, fans,
and conveyors.
The induction motor can be connected directly to a 50 or 60 Hz commercial main, making a
system very affordable. These days, more and more induction motors are being controlled by
AC variable speed drives (inverter).
( See the Speed Control Pages)
These drives can control the frequency of the AC supply fed to the windings,
making the induction motor a growing competitor in the controlled velocity market, where
the DC motor previously dominated. One needs to insure that the motor is inverter rated
before coupling the two together. The problem of slip will still exists, so one can have
controlled speed but not precise speed, unless you include tachometer feedback and
controls to accept this.
Sizing a Motor for the Job
Selecting the right motor for the job can sometimes be the most confusing
aspect of a motion control problem. A priority list must be made as to what properties of
the motor system are to be optimized. These properties may include, motor efficiency,
motor torque, motor power, reliability, and of course, cost. Generally torque is the
driving factor in a motor's weight, size and consequently cost, so knowing the torque
requirements is paramount.
The key is to try an reduce the torque requirements of the motor
by increasing the RPM or the mechanical advantage (gearing).
Is not the size that counts, its how you use it:
Bigger is not always better, the most important parameter to optimize in a
motion system is torque. If you have an application that requires high torque at slow
speed, a gear reduction unit of some sort can sometimes dramatically reduce the motor size
or increase the motor's efficiency.
If you need high speed at low torque, a large motor can have
excessive iron loss. 1. reduce the frequency (RPM) of the motor to reduce the eddy
current loss or 2. reduce the size of the motor to reduce the hysteresis drag.
