partially placed inside the hollow rotor 6 of the engine.
The rotor 6 of the motor contains 20 highly efficient permanent magnets.
On the stator 5 having 24 slots, phase windings 7 of the motor armature are
placed, as well as three-phase tachometric windings for measuring the speed
of rotation of the rotor and the excitation winding of the rotor position sensor
(RPS).
The design of RPS has features that significantly simplify the design and
reduce the volume of the mechatronic motion module. In contrast to the com-
monly used RPS based on Hall sensors, the RPS used in this module is not an
independent constructive element but rather an «implicit» device.
Its functions are realized with the help of several elements: tachometric
windings, excitation windings located in specially manufactured stator orifices
in the immediate vicinity of tachometric windings, and electronic equipment of
mechatronic motion module.
The advantage of the «implicit» RPS under consideration is that there is
no need for phasing it when setting up the module, since it is provided by the
engine design. In addition, such a RPS signals the rotor position continuously,
which allows without any problems to form sinusoidal currents in the phase
windings of the motor. This capability improves the properties of the mecha-
tronic module as a result of reducing the ripple of the motor torque.
The stationary part of the induction position sensor (IPS), inside which the
screw moves forward, has a screw thread similar to the screw itself, and is, in
fact, a nut. The difference is that the screw has a left thread, and the sensor nut
is the right one. In addition, to ensure a free movement of the screw inside the
IPS, the inner diameter of the sensor nut must be slightly larger than the outer
diameter of the screw.
The fixed part of the IPS consists of two half-wings, one of which is rotated
relative to the other half a turn. Inside it are located the axial winding of
excitation and the output windings wound in the grooves (sinus and cosine of
the sensor winding), each of which has four sections, connected in series and in
pairs in pairs. The magnetic flux generated by the alternating current flowing
through the excitation windings is closed through the first half-nut, the screw
and the second half-nut. In doing so, it permeates the sine and cosine windings
of the IPS and induces an electromotive force (EMF) in them. The threads of
the screw thread and the sensor nuts play the role of pole pieces.
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When the position of the screw is changed as a result of the displacement
of the protrusions of the threads of the screw relative to the protrusions of the
threads of the sensor nut, the resistance of the magnetic circuits causing the
formation of EMF induced in the output windings of the IPS varies differently.
As a result, the EMF amplitudes in the sine and cosine of the sensor are diffe-
rent and depend on the position of the screw relative to the fixed sensor nut.
Thus, the harmonic signals induced in the windings are modulated in amplitude
in function of the displacement of the screw.
If the voltages arising in the sinus and cosine windings are subjected to
phase-sensitive rectification, signals are generated whose envelopes are propor-
tional to the sinus and cosine from the displacement of the screw, their periods
corresponding to one step of the screw.
Fig. 1.6
shows the mechatronic module of linear motion of the output link. It
consists of an asynchronous electric motor 1 with a hollow shaft 2, a ball screw
drive transducer including a screw 3, balls 4, a compound nut 5 rigidly attached
to the shaft 2, the guide 6, the electromagnetic brake 7, the photo impulse
sensor 8 and the housing 9.
Figure 1.6 – Mechatronic module of linear motion of the output link
When the rotor of the electric motor 1 rotates, the shaft 2 rotates the nut
5 which, through the balls 4, causes the screw 3 to move forward. To prevent
the rotation and reduce friction, when the screw 3 is moved, three longitudinal
grooves are made in it, into which the balls 10 of the guide 6 enter. The
amount of movement of the screw 3 fixes the photoimpulse sensor 8. The
electromagnetic brake 7 fixed in the housing 9, in the event of a power failure,
triggers and stops the screw.
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Figure 1.7 – The design of a two-degree (two-coordinate)
mechatronic motion module
The construction of a two-degree (two-coordinate) mechatronic module of
motion is shown in Fig. 1.7. The module consists of two motors 1 and 2, a wave
converter of motion with a fixed flexible wheel 3, a movable rigid wheel 4 and
a cam wave generator 5, a two-stage motion transducer consisting of a bevel
gear 6 and 7, a wave motion converter with a fixed rigid wheel 8, a flexible
flexible wheel 9 and a cam wave generator 10, two photo-pulse sensors 11 and
12. When the motor 1 is turned on, the wave generator 5 starts to rotate and the
rigid wheel 4 together of the associated housing 13 is set in motion.
When the motor 2 is turned on, rotation of its shaft through a pair of gears
6 and 7 drives the wave generator 10 and the flexible wheel 9 together with
the output shaft associated with it is driven. The pulse sensors 11 and 12 are
designed to determine the position and movement of the housing 13 and output
shaft 14, respectively.
The MAXON mechatronic motion module is shown in Fig. 1.8 [9].
It consists of a collector motor 1, a two-stage motion transducer 2 and a
photo-impulse sensor of position 3. The motor includes a winding 4, a magnet
5, a collector 6, brushes 7, a flange 8, a bearing 9, a shaft 10 ending with a
pinion 11 (pinion shaft) and the cover 12. Each stage of the 2K-H planetary
motion transducer with one external and one internal gearing has two central
wheels 11 and 13 (the first stage), a carrier 14 and satellites 15. For mounting
the bearing 9, there is a special plate 16. Bearing 17 is mounted in the flange 18,
the motion converter, through which the output shaft 19.
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Figure 1.8 – Mechatronic motion module by MAXON
The photo-pulse position sensor is used to determine the position and
displacement of the output shaft of the mechatronic motion module. The
most important stage in the development of mechatronic modules of motion
has been the development of modules of the «engine-working organ» type.
Such constructive modules are of particular importance for technological
mechatronic systems, the purpose of which is to implement the purposeful
action of the working body on the work object. Mechatronic motion modules
of the «motor-working» type are widely used in grinding and milling machines
called motor-spindles.
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