JPH02303352A - Electronic commutator motor - Google Patents

Abstract

PURPOSE: To weaken or suppress commutation noise by providing two stator windings to be excited alternately and controlling the ampere turn of these two stator windings during a commutation process. CONSTITUTION: Each of two switching transistors 30, 31 has an emitter connected with the minus pole of supply voltage and a collector connected with the plus pole of supply voltage through one of two windings 32, 33 of a coil 22. Consequently, the two windings 32, 33 are excited alternately through alternate switching of the transistors 30, 31 and thereby the windings 32, 33 are switched in the magnetically opposite directions. In this regard, two winding currents are overlapped with time due to a capacitor 23 bridging the connecting terminals of the coil 22 and thereby a force to be generated from the coil 22 is compensated at the moment of commutation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic commutator motor, also referred to as a brushless DC motor or an electro-commutator motor, according to the preamble of claim 1.

BACKGROUND OF THE INVENTION Electric motors of this type are known in numerous forms, for example also in various forms of electronic commutator devices. In such electric motors, there is a problem in that commutation noise occurs when switching the magnetic flux passing through the electronic commutator device to the working winding.

To prevent this, it has already been proposed to control the control transistor in a linear region during the commutation phase in an individually constructed control device, so that relatively flat current edges are obtained. There is. This certainly avoids commutation noise, but requires high circuit costs.

Means for solving the problem In contrast, the electronic commutator motor according to the invention has the features of claim 1, in which the transistors can be designed as pure switching transistors,
As a result, for example, digital high-power ICs can be used, with the advantage that commutation noises can be weakened or suppressed, for example by simple capacitors across the control connections of the stator windings. This is achieved by causing the two winding currents to overlap in time by means of a capacitor or another circuit element,
This compensates for the forces occurring in the coil at the moment of commutation, so that the alternation of forces in the coil lasts for a relatively long period of time. Relatively slow changes in the alternating forces generate significantly less noise. Another advantage is that commutation noise can be reduced or suppressed using simple capacitors without operating an electronic control unit. This makes it possible to use commercially available components, for example commercially available Hall ICs, which, in addition to being simple in construction, provides a cost-effective solution.

Advantageous embodiments and improvements of the electric motor according to claim 1 are possible with the features according to the other claims.

Forming the stator windings as bifilar coils improves electromagnetic coupling, provides a simple structure, and reduces manufacturing and assembly costs.

The sensor element is preferably designed as a Hall sensor, which Hall sensor together with the electronic control device is preferably combined into an integrated unit. This type of high-output Hall IC, for example, realized digitally, has a sensor element, an electronic control unit, and a capacitor, which are commercially available as compact components that do not require much cost, arranged on one substrate, and this substrate is attached to a stator. The above arrangement can be further simplified and improved if the basic part is fixed on the side on which the rotor is located. In particular, if the stator windings are additionally arranged on this substrate, the entire electrical and electronic components of the motor can be preassembled on the substrate and mounted as a finished component on the basic stator component. be able to. This also makes assembly easier.

The base plate is preferably designed in the form of a perforated disk and in the assembled state grips the shaft and/or the bearing element for the rotor, so that the base plate can be securely fastened to the stator basic part. I can do it.

By forming the basic stator member from synthetic resin,
Production can be additionally made cheaper, in that the soft iron component material for the magnetic flux, in particular the soft iron disk, is inserted into the basic stator element, and the soft iron component is preferably fixed by means of a base plate that is also inserted. and closed.

Embodiments Next, the present invention will be explained in detail with reference to the drawings, with reference to the illustrated embodiments.

The electronic commutator motor shown in FIGS. 1 to 3 (also known as
In a brushless DC motor or electro-commutator motor), a rotor 10 is rotatably mounted on a stator 12 by means of a shaft 11 .

The rotor consists of a circular, flat disk 13. This disk has a diameter of 8.
It supports a retaining member 14 for two vertically oriented blower vanes 15 and, on the opposite side, a ring disc 16 of magnetizable material. The disk is fixedly magnetized so that four sector areas with alternating magnetic poles are formed. This can be, for example, a sintered magnet. The shaft 11 is fixed within the disk 13 and the retaining member 14 .

The stator 12 essentially consists of an approximately disc-shaped basic member 17 made of synthetic resin. In the central region of this basic element, a tubular receptacle 18 for a bearing 19 which rotatably supports the shaft 11 is raised. This receiving portion 18 is integrally molded with the stator basic member 17. The ring-disc-shaped base plate 20 has a central hole with a diameter that substantially corresponds to the outer diameter of the receptacle 18, so that the base plate 20 is mounted radially fixedly on the stator basic part 17. be able to. Due to corresponding recesses in the stator basic part 17, the substrate 2
0 is fitted into the stator basic member 17 such that the upper surface of the stator basic member 17 and the upper surface of the substrate 20 are in one plane. In the simplest case, this fixation can be carried out by gluing or clamping, but other known fixing methods are, of course, also possible. Substrate 2 surrounding receiver 18
A ring groove-shaped channel, open in the direction 0, is used to accommodate a ring-shaped soft iron plate 21 for guaranteeing the magnetic flux in the electric motor. This soft iron plate 21 is fixed to the stator basic member 17 by a substrate 20.

A bifilar coil 22 forming two stator windings is disposed on the substrate 20. This coil 22 is arranged on both sides such that its diameter in one direction substantially corresponds to the diameter of the substrate 20, while its diameter in the direction perpendicular thereto is significantly smaller, so that its inner diameter extends as far as the receptacle 18. The surface looks like it has been crushed. This crushed shape allows the coil 22 to be placed on the outside of the coil 22.
A free space is formed on the substrate 20 on both sides, and a capacitor 23 and a high power Hall IC 2 are placed on one side in the case
4 is disposed on the substrate 20. The connecting lines are not shown for simplicity, but are evident from the circuit diagram shown in FIG.

4130, three elements, namely coil 22;
A connection line between the capacitor 23 and the high power Hall IC 24 is shown based on the circuit diagram.

The digital high output Hall IC 24 is, for example, a module U.
GS3275 is commercially available as GS3275 and will be briefly described below: The voltage regulator 25 connected to the positive and negative poles of the supply voltage source is connected to other elements, namely a Hall element 26, an amplifier 27, e.g. as a Schmitt trigger. Threshold stage 28 formed, inverter 29
, as well as the two switching transistors 30, 31. A Hall element 26 arranged in the magnetically active region of the magnetized cylinder disc 16 detects the alternating magnetization during rotation of this ring disc 16, and the correspondingly generated signal is transmitted to the amplifier. It is amplified at 27 and fed to a threshold stage 28. The bases of the two switching transistors 30, 31 are each connected on the one hand via an inverter 29 to the output of the threshold stage 28 and on the other hand directly to the output of the threshold stage 28, so that 2 one transistor 30.3
1 has in each case an opposite switching state, ie one transistor is in each case switched off and the other transistor is in the conducting state. Each time there is a change in the magnetization of the rotating ring disc 26, the two switching transistors 30, 31 are switched into the respective opposite switching state.

The emitters of the two switching transistors 30, 31 are connected to the negative pole of the supply voltage, while the collectors are respectively connected to the two windings 32 of the bifilar coil 22.
．． 33 to the positive pole of the supply voltage. For this reason, the switching transistor 30.31
The alternating switching states of the two windings 32,33
are alternately excited. Since these windings are switched magnetically in opposite directions to each other (indicated by the two dots), the direction of the magnetic field changes each time the switching state of the switching transistor 30, 31 changes, so that the motor is driven. Ru.

Based on the bifilar coil structure, alternating commutation of the two winding currents generates alternating forces that can result in commutation noise. switching transistor 30
．． By the capacitor 23 bridging the two collectors 31 and thus the connection terminals of the coil 22, a temporal overlap of the two winding currents is realized, which compensates for the forces occurring in the coil at the point of commutation and The alternation of forces at extends over a relatively long time. Due to the relatively slow change in the alternating force, the commutation noise is weakened or suppressed, and at the same time good interference protection is achieved.

It is of course possible in a variant of the illustrated embodiment to use two separate coils instead of the two-turn coil. For example, the number of volumes! 000.

Instead of the Hall element or high-power Hall IC, another element sensitive to magnetic fields or an element which detects the position of the rotor and controls the stator windings in a corresponding manner, which is particularly suitable for digital control. Of course, you can also use .

Instead of a capacitor, it is also basically possible to use other circuit elements or circuit arrangements that cause the two stator windings to carry current together during the commutation process, in which case the force The effect is compensated for a short time. For this purpose, for example, suitably controlled semiconductor switches can be used.

Effects of the invention The electronic commutator motor of the present invention can use pure switching transistors as transistors, so for example digital high-power ICs can be used, for example simple capacitors can be connected to the control connections of the stator windings. It has the characteristic that commutation noise can be weakened or suppressed by providing it between the terminals.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view illustrating an embodiment of the electronically commutated motor of the present invention, and FIG. 2 is a plan view of a stator basic member including a substrate with the rotor removed. , 3rd
The figure is a plan view of the rotor, and FIG. 4 is a circuit diagram for explaining electrical connections of individual elements. 10... Rotor, 11... Shaft, 12... Stator,
13... Disc, 14... Holding member, 15...
Blowing blade, 16... Ring disk, 17... Basic member, 18... Receiving part, 19... Bearing, 20... Substrate, 21... Soft iron member, 22... Coil, 23・・・
・Capacitor, 24...High output Hall IC125...
・Voltage regulator, 26...Hall element, 30.31...
・Switching transistor, 32.33...Stator winding FIG, 1

Claims (1)

[Claims] 1. A stator having at least one stator winding, a rotor having a magnetized region, and a rotor provided on the stator for detecting the position of the magnetized region. An electronic commutator motor comprising a sensor element and an electronic control device for energizing at least one of said stator windings in dependence on a sensor signal, wherein said electronic control device (27-31) alternately energizes said stator windings. Two stator windings (32, 33) are provided, wherein during the commutation process the two stator windings (32, 33)
, 33) circuit element (23) for controlling ampere turns of
An electronic commutator motor characterized by being provided with. 2. Electronic commutator motor according to claim 1, characterized in that the circuit element is a capacitor (23) bridging the control connections of the stator windings (32, 33). 3. The stator windings (32, 33) are bifilar coils (
3. The electronic commutator motor according to claim 1, wherein the electronic commutator motor is configured as: 22). 4. The coil (22) has a shape in which both sides are crushed, and the space created by the crushed shape is used for the sensor element (26) and/or the electronic control device ( 27-31) and/or capacitor (23)
4. An electronic commutator motor according to claim 3, which is used to accommodate a motor. 5. Electronic commutator according to claim 1, wherein the rotor (10) has a disk of magnetizable material, which disk consists of four alternately magnetized regions. Electric motor. 6. Electronic commutator motor according to claim 1, wherein the sensor element (26) is designed as a Hall sensor. 7. The Hall sensor (26) is connected to the electronic control device (27-31
) in the form of an integrated module.
Electronic commutator motor as described. 8. Electronic commutator motor according to claim 7, wherein the integrated element (24) is configured as a digital high-power Hall IC. 9, sensor element (26), electronic control device (27-31)
and the capacitor (23) are arranged on a substrate (20), which substrate is fixed to the stator basic member (17) on the side on which the rotor (10) is located.
8. The electronic commutator motor according to any one of 8 to 9. 10. The base plate (20) according to claim 9, wherein the base plate (20) is formed in the form of a perforated disk and in the assembled state holds the shaft (11) and/or the bearing member (19) for the rotor (10). Electronic commutator motor. 11. Electronic commutator motor according to claim 9 or 10, wherein the stator windings (32, 33) are arranged on the substrate (20). 12. The substrate (20) and the stator basic member (17) are
12. Electronic commutator motor according to claim 9, further comprising a soft iron member (21) for the magnetic flux, for example a soft iron disk. 13. The electronic commutator motor according to any one of claims 9 to 12, wherein the stator basic member (17) is made of synthetic resin. 14. Electronic commutator motor according to any one of claims 9 to 13, wherein the substrate (20) is fitted into the stator substrate member (17).