JPS6146160A - Dc commutatorless motor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A commutatorless direct current motor with dependent sensors, the sensors being arranged in the range between two adjacent stator species of different polarity and during operation the excitation current is These stator magnetic fluxes are also controlled, and the sensor is arranged in the leakage region of the stator poles so that the detected negative feedback component of the stator leakage flux exceeds the positive feedback component. It is related to the improvement of

The invention relates in particular to a commutatorless motor of the opening type which generates an additionally active reluctance moment during the gap of the electromagnetically generated rotational moment, in which case in particular the magnetic flux conductor is The negative feedback component of the stator leakage magnetic field is captured more strongly than the positive feedback component. That is, this allows the current in the stator winding to change gradually from the solid line to the dotted line in FIG.

In the conventional devices mentioned at the outset, these flux conductors are correspondingly asymmetrically shaped and are therefore used in only one direction. This asymmetry becomes even stronger when the sensor is mounted in the opposite direction of rotation. However, this makes the leakage magnetic field very strong or even excessive.

The object of the invention is to achieve an expanded range of applications in a device of the type mentioned at the outset, with as little additional expense as possible. In particular, the purpose is to improve the turning on and turning off (rectification) of excitation current in the conventional motor mentioned at the beginning.

The present invention provides that the parts of the rotor poles that act on the motor are arranged in such a way that the edges of the rotor pole gaps are in front of the parts of the rotor that act on the motor in the direction of rotation (angle γ). This is solved by

Since, for example, a rotational movement of the sensor makes the motor less efficient, the combination of both of these measures allows for the first time in a simple device to achieve perfect results.

According to the invention, the sensor is likewise offset from the center of the magnetic gap of the stator, viewed in the direction of rotation of the rotor.

In high-power, i.e. high-speed motors, the displacement of the rotor pole gap acting on the sensor according to the invention is larger, for example, so that the sensor is displaced in the direction of rotation on the stator side, that is, away from the rotor pole gap. With a dog comb, the current rise is accelerated to achieve trapezoidal excitation, and the rotor magnet is magnetized trapezoidally to achieve as good efficiency as possible.
``The sensor displaced from the stator gap according to the present invention can be used for all devices.
According to 14067. In combination with the present invention, this can be used in all directions of rotation and can be used structurally for all purposes.

In some cases, a low electrical accuracy is acceptable, so it also makes economic sense to have a device in which the sensor element is not embedded between ferromagnetic slots for the magnetic flux, and the stator leakage flux is reduced to %. This is the case in the conventional device at the beginning, which also acts on this sensor element.

A sensor arrangement without any soft iron conductor protruding directly from the sensor element (often a so-called Hall generator) is therefore particularly advantageous in some cases. To suppress the leakage effect of the stator on the sensor, a soft iron flux conductor emanating from the stator is allowed to extend to the sensor. For example, the end sheets of the stator laminate can be made into curved pieces in a simple manner.

Next, the present invention will be explained with reference to illustrated embodiments.

FIG. 2 shows a sectional view of a commutatorless DC motor according to the invention. IO is a laminated stator, and stator windings 24 and 25 are wound in its grooves 8 and 9.

In the bearing support tube 19 a rotor shaft 39 is supported in a pole bearing 38, which shaft supports at its upper end a rotor bell 42 of the outer rotor. The rotor bell-shaped body is shaped to open downward and surround the stator 10. A ring-shaped rotor magnet 143 is arranged inside the rotor bell-shaped body 42 . The magnet is radially magnetized as indicated by N and S, and is generally trapezoidal with a relatively small pole gap of 176° and 177°.

Pole gap 176 of rotor magnet 143 acting on stator IO
．． 177 is relatively narrow, but widens in the portion of magnet 1430 located on the underside of stator 10, and this lower portion of magnet 143 serves to control Hall generator 130.
This is shown in DE 24 19 432 A1. The rotating preform 42 serves as a magnetic closed circuit for the rotor magnet 143. The lower free end 44 of the bell-shaped body 42 extends beyond the rotor magnet 143 in the axial direction.

Sensor 130 configured symmetrically in FIG. 2.3
is shifted in the direction of rotation by an angle ε (this is equivalent to increasing the negative feedback component of the stator leakage flux),
In one direction, the rotor seed gap 176, 177 has an edge region 179 which is offset by an angle γ in the direction of rotation 63 in its region 178 acting on the sensor (this does not mean that it is too late or too early in FIG. Best current rise 7
9 to 2).

FIG. 4 shows the deformation of the edge region 179, J 80 of the rotor pole gap region 178, which acts on the sensor.

FIG. 11 shows an enlargement of one side of region 178, so that only R179 has been displaced, while the deformation of region 178' has given a complete pole gap displacement in the sensor region 9 and further in the direction of rotation. The existing edge 179' is slight, but larger (
Angle B) is shifted.

The transition part is represented as a circle. In practice, induced distribution is almost identical to this. However, while this is desirable, operationally discontinuous transitions are not.

From this point, the deformation shown by dotted lines (edge lines 179" and 180"
) is a gradual interruption (and connection) of inductance.
It has the same effect as enabling.

Figures 4 and 5 show a rotationally offset, magnetically weakened, rounded gap in the sensor area. A device according to FIG. 3 with a wider pole gap is usually adequate for slowly rotating motors. There is also a sharp limit at the edge 179 of the pole gap, which causes the Hall voltage to increase over time. It means to change.

This slope of the Hall voltage, however, is not very steep during cut-off. This is because the edge 179' in the w
180") increases with the movement from O. This further increases the deviation angle (γ">T':β">β', the fifth
Figure) can be made larger.

The shape of the edge 179, 179' or 179'' takes into account the course of the Hall voltage, and as the negative feedback part exceeds the positive feedback part, positive feedback is avoided and the slope of the Hall voltage cannot rise. These two methods (can reduce the cut-off voltage) are used for high-speed motors and high-resistance motors with large time constants, such as the time constant of the time alternation, the poles and gaps can be reduced as shown in Figure 3. Since the enlarged part is placed in front in the direction of rotation, the size of the pole gap is maintained in the sensor area, and these are
It is preferable to shift in the direction of rotation as shown in the figure. S with front side marked 180, I 80' or 180"
By advancing the head or nose of the pole together,
In a preferred manner in high speed motors, the input of the next motor winding is guided into the path at the correct time (front 180, 1
80'.

iso'' course is similar to edges 179, 179', 179'').

The power-on operation is initially limited by the effect of the winding inductance t, and therefore there is virtually no problem with the power-off. On the other hand, the current rise upon switching on should preferably be made somewhat steeper so that the current course actually occurs even in region 79, as shown in FIG. The current profile should therefore be as trapezoidal as possible from the point of view of efficiency.

As mentioned above, there is a problem in that the current gradually reaches the full value when the motor is turned on, which deteriorates the motor efficiency. This is because, at a high rotational speed and a predetermined motor winding (inductance), without a displacement of the pole gap, the t current will not reach its full value, i.e., pulse high, in the pre-breakdown state, or will reach it only slowly. .

In high speed motors, the pulse duration (see FIG. 1) is preferably relatively short so that the current reaches its full height particularly quickly.

It is therefore particularly expedient for the gap to be only shifted (not enlarged) in the sensor area so that an early commutation takes place, compensating for the retarding effect of the inductance of the motor windings on the current and eliminating the drawbacks.

The current rise can be controlled by the configuration of the front surface 180, 180', 180''.

The invention in the form of FIGS. 4 and 5 is particularly advantageous in large and/or high speed motors with pre-pull circuits and single windings. This is because the ratio L/R is particularly large (thick O
(u line), therefore the time constant of the winding becomes a difficult problem.

In the bridge circuit, there is no problem with current interruption. This is because the idling node inherits the current.

Although the current rise is difficult to suppress, the angular feedback component is also surpassed in the pringe circuit due to the reduction of the disturbing oscillatory tendency (due to the decoupling effect), i.e. the configuration of the invention with such a bridge circuit is It will be advantageous.

Furthermore, in the case of a two-pulse commutatorless (alternating field) electric motor (DE-OS 22 25 442), the spark disturbance voltage is significantly reduced. This is because such motors (referred to in the literature as single-phase, two-pulse, commutatorless motors, etc. in which the stator windings generate a pure alternating magnetic field) have large di/dt values without any additional measures. . From this point of view, the present invention in every case inherits the current from which the phase was previously energized, and therefore more and more small current pulses per time exit through the circuit. Multiphase stator windings are also advantageous.

These various configurations of the pole gaps of the permanent magnets, especially in the rotor, naturally have a common significance for electric motors in which the magnetic rotor area acts on conductive-magnetic sensors.

[Brief explanation of drawings]

FIG. 1 is a current waveform of the stator winding of a motor of the type to which the present invention is applied, FIG. 2 is a cross-sectional view of an embodiment of the motor according to the present invention, and FIG. 3 is a cutting line XI->ff of FIG. 2. A closer view of the rotor magnet, FIG. 4 shows a similar modification to FIG. 3, and FIG. 5 also shows a further modification. 176, 177・・・・・Snow rotor pole gap 17
8・・・・・・・・・・・・Polar gap region 179, 1
79', 179''...edge 10...
...Stator 42...Rotor bell-shaped body 43...Rotor bell-shaped body 1 Figure 2 figure

Claims (1)

[Scope of Claims] 1. A commutatorless DC motor equipped with a magnetically dependent sensor for detecting magnetic flux coming from a rotor, which sensor is arranged in a range between two adjacent stator poles of different polarities. and which during operation controls the excitation current and therefore also these stator fluxes, and furthermore, its sensors are arranged in the leakage regions of the stator poles such that the detected negative feedback component of the stator leakage flux exceeds the positive feedback component. In a commutatorless DC motor,
The parts of the rotor poles that act on the sensor are arranged in such a way that the edges of the rotor pole gaps are in front of the rotor parts that act on the motor in the direction of rotation (angle γ). Commutatorless DC motor. 2. The commutatorless DC motor according to claim 1, wherein the sensor is similarly shifted from the center of the stator pole gap in the rotational direction of the rotor (angle ε). 3. A commutatorless DC motor according to claim 2, characterized in that the sensor is a complete device magnetically symmetrical with respect to a plane passing through the motor axis. 4. A stator that generates an additional actuating reluctance moment in the gap of the electromagnetically generated rotational moment and generates an alternating magnetic field; or Commutatorless DC motor according to item 2 or 3. 5. A commutatorless DC motor according to claim 1, 3, or 4, wherein the high-speed rotor receives trapezoidal magnetization in the peripheral direction of a permanent magnet acting on the motor. . 6. Commutatorless DC motor according to any one of claims 1 to 5, characterized in that the stator has only one winding and is operated in a bridge circuit.