JP4703288B2 - Permanent magnet synchronous motor - Google Patents

Description

  The present invention relates to a rotary field type synchronous motor using a permanent magnet as a rotor, and more particularly, to a permanent magnet type synchronous motor that uses a magnetic sensor to detect the magnetic pole position of a rotor and controls rotation.

  As a kind of synchronous motor, there is a rotating field type synchronous motor that uses a permanent magnet for the rotor (rotor), and it is called a DC brushless motor because it does not require a brush for power supply. Therefore, it is also advantageous as a relatively small motor. Therefore, in recent years, it is frequently used in, for example, an air conditioner.

  By the way, this DC brushless motor generates a rotating magnetic field by detecting the rotational position of the rotor and switching the armature current so that torque is generated in the rotor. Therefore, it is necessary to detect the rotational position of the rotor. As a magnetic pole position detector at this time, a magnetic sensor is generally used, and the rotational position of the rotor is detected by detecting magnetism by the magnetic pole of the rotor. Is detected (see, for example, Non-Patent Document 1).

  Therefore, an example of a conventional permanent magnet type synchronous motor provided with such a magnetic sensor for detecting the magnetic pole position will be described with reference to FIG. 4. First, in the permanent magnet type synchronous motor according to this prior art, as shown in the figure, A stator having a stator core 1 and a stator winding 2 is inserted into the housing 3 and firmly fixed.

  End brackets 4a and 4b are attached to both ends of the housing 3 by inlay fitting. At this time, the rotor 5 is inserted into the stator. The permanent magnet 10 is provided on the circumferential surface thereof, thereby forming a field magnetic pole. The rotor 5 is attached to a rotor shaft 6. The rotor shaft 6 is rotatably supported by the end bracket 4 by bearings 7a and 7b such as ball bearings, whereby a permanent magnet rotating field type is obtained. It constitutes the main body of the synchronous motor.

  Next, in this prior art, in order to detect the rotational position of the rotor 5, a magnetic pole position detection substrate 8 is provided at one end of the stator, and a magnetic sensor such as a Hall element is mounted on this, By detecting the magnetic field generated by the permanent magnet 10 of the rotor 5 by the sensor, a magnetic pole position detection signal representing the rotational position of the rotor 5 can be extracted. Then, this magnetic pole position detection signal is supplied to a control circuit of a permanent magnet type synchronous motor (not shown).

  Therefore, this control circuit controls the armature current supplied to the stator winding 2 based on the magnetic pole position detection signal so that a rotating magnetic field for generating torque in the rotor 5 is generated by the stator. Thus, an operation as a permanent magnet type synchronous motor can be obtained.

  By the way, in such a permanent magnet type synchronous motor, since rotation control is performed according to the detection result of the magnetic pole position of the rotor, it is necessary to accurately position the magnetic pole position detection sensor with respect to the stator core 1. . Therefore, in the prior art, the magnetic pole position detection board 8 is fixed to the housing 3, the end bracket 4a, the bobbin on which the stator winding 2 is applied, or the like with a screw or an adhesive directly through a holder. It is supposed to keep.

In the prior art, when a magnetic sensor such as a Hall element serving as a magnetic pole position detector is attached to the magnetic pole position detection substrate 8, a holder or the like is used so that desired accuracy can be easily obtained.
“Sine-wave drive system using low-resolution position sensor” Notohara, et al. 2001 IEEJ Industrial Application Conference, No.87 (2001-8)

  The above prior art cannot be considered that the positioning accuracy of the magnetic pole position detector must be maintained with respect to the stator core, and there is a problem in maintaining the rotational position detection accuracy.

  In the above-described prior art, the magnetic pole position detection board on which the magnetic pole position detector is mounted is fixed to the housing, the end bracket, or the fixed, although the positioning accuracy of the magnetic pole position detector must be maintained with respect to the stator core. It is attached to a bobbin or the like provided with a child winding 2.

  For this reason, it becomes difficult to obtain accuracy in positioning of the magnetic pole position detector with respect to the stator core, resulting in a problem that the detection accuracy of the rotational position is lowered.

  An object of the present invention is to provide a permanent magnet type synchronous motor that can easily maintain the positioning accuracy of a stator core and a magnetic pole position detector.

An object of the present invention is a permanent magnet type synchronous motor that uses a magnetic sensor to detect and control the magnetic pole position of a rotor, and has a magnetic pole position detection board on which the magnetic sensor is mounted. Has a protrusion corresponding to the position of the magnetic pole of the stator core and part of the shape having substantially the same width as the magnetic pole, and the magnetic sensor is fixed to the protrusion, and the magnetic pole position detection This is achieved by arranging the substrate on the end face of the stator core between the end face of the stator core and the stator winding so that the widths of the projections and the magnetic poles are matched .

  At this time, the magnetic pole position detection board may have a planar shape substantially the same as the shape of the end face of the stator core.

  At this time, three magnetic sensors may be mounted on the magnetic pole position detection board.

  Further, at this time, three magnetic pole position detection boards may be provided, and the magnetic sensor may be mounted on each of the three magnetic pole position detection boards.

  According to the present invention, since the magnetic pole position detection board is attached to the end face of the stator core by applying the stator winding, the accuracy of the mounting position of the magnetic pole position detection board with respect to the stator core can be improved. In addition, it is possible to reduce mounting errors and variations in the magnetic pole position detection signal.

  Hereinafter, a permanent magnet type synchronous motor according to the present invention will be described in detail with reference to embodiments shown in the drawings.

  FIG. 1 shows an embodiment of a permanent magnet type synchronous motor according to the present invention. Here, the same or equivalent parts as those of the conventional permanent magnet type synchronous motor described in FIG. It is.

  Here, first, also in the embodiment of FIG. 1, as shown in the figure, a stator in which a stator winding 2 is applied to a stator core 1 is inserted into a housing 3 and firmly fixed.

  Next, end brackets 4a and 4b are attached to both ends of the housing 3 by inlay fitting. At this time, the rotor 5 is inserted into the stator. Is provided with a permanent magnet 10 on its circumferential surface, thereby forming a field magnetic pole. The rotor 5 is attached to a rotor shaft 6. The rotor shaft 6 is rotatably supported by the end bracket 4 by bearings 7a and 7b such as ball bearings, whereby a permanent magnet rotating field type is obtained. It constitutes the main body of the synchronous motor.

  Also in this embodiment, in order to detect the rotational position of the rotor 5, a magnetic pole position detection substrate 8 is provided at one end of the stator, and a magnetic sensor such as a Hall element is provided as a magnetic pole position detector. The magnetic pole position detection signal representing the rotational position of the rotor 5 can be taken out by mounting and detecting the magnetic flux generated by the permanent magnet 10 of the rotor 5 by this sensor.

  Also in this embodiment, this magnetic pole position detection signal is supplied to a control circuit of a permanent magnet type synchronous motor (not shown), whereby the armature current supplied to the stator winding 2 is controlled and rotated. A rotating magnetic field for generating torque in the child 5 is generated by the stator, and as a result, an operation as a permanent magnet type synchronous motor can be obtained.

  By the way, in such a permanent magnet type synchronous motor, since rotation control is performed according to the detection result of the magnetic pole position of the rotor, it is necessary to accurately position the magnetic pole position detector with respect to the stator core 1.

  Therefore, this embodiment is characterized in that the magnetic pole position detection board 8 on which the magnetic pole position detector is mounted is directly attached to one end face of the stator core 1 as shown in the figure. In this respect, it is clearly different from the prior art of FIG.

  Here, FIG. 2A shows a state where the magnetic pole position detection board 8 in FIG. 1 is viewed from the right side of FIG. 1. In this embodiment, the magnetic pole position detection board 8 includes Thus, three magnetic pole position detectors 9 are provided as magnetic sensors. This is because, in the case of a three-phase permanent magnet type synchronous motor, for example, three magnetic sensors such as Hall elements are mounted to detect the rotational position of the rotor.

  At this time, as is apparent from FIG. 2 (a), this embodiment is a case where the stator is of a concentrated winding type. Therefore, in this case, the magnetic pole position detection board 8 is attached to the stator core 1. The shape of the end faces of the three magnetic pole parts on the inside and the planar shape of the same shape as the end face of the yoke part connecting these magnetic pole parts are made, and the three magnetic pole position detectors 9 are respectively Attach it so that it is located at the magnetic pole.

  Next, FIG. 2 (b) shows, for example, a part on the front side in FIG. 2 (a) of the uppermost magnetic pole portion in the magnetic pole portion shown in FIG. 2 (a). As seen from the A direction, as is apparent from this figure, the part having the same shape as the magnetic pole part of the magnetic pole position detection substrate 8 is wound around the end face of the magnetic pole part of the stator core 1 and this part. It is directly attached to the end face of the magnetic pole portion of the stator core 1 while being sandwiched between the stator windings 2.

  Of course, the magnetic pole position detection substrate 8 is insulated from the stator 1 and the stator winding 2.

  Therefore, in this embodiment, after the magnetic pole position detection substrate 8 is overlaid on the end face of the stator core 1 and then the stator winding 2 is wound around the magnetic pole portion of the stator core 1, the magnetic pole position detection substrate 8 is The stator winding 2 is fixed to the end face of the stator core 1, and the mounting of the magnetic pole position detection board 8 is completed.

  At this time, an adhesive may be interposed between the end face of the stator core 1 and the magnetic pole position detection substrate 8 so as to be bonded by the adhesive.

  According to this embodiment, since the planar shape of the magnetic pole position detection board 8 is the same as the end face of the stator core 1, when the magnetic pole position detection board 8 is superimposed on the end face of the stator core 1, The positional relationship can be easily set in a correct state, and as a result, the magnetic pole position detection substrate 8 can be highly accurately aligned with the stator core 1.

  Here, also in this embodiment, in order to mount the magnetic pole position detector 9 such as a Hall element on the magnetic pole position detection substrate 8 with high positional accuracy, for example, positioning by a holder or the like is used as in the prior art. Yes.

  Therefore, according to this embodiment, the magnetic pole position detection substrate 8 is easily positioned with respect to the stator core 1 with high accuracy, and thus the magnetic pole position detector 9 is positioned with respect to the stator core 1 with high precision. As a result, the permanent magnet rotating field type synchronous motor can be controlled with high accuracy.

  By the way, in order to insulate the stator core 1 and the stator winding 2 from each other, the magnetic pole position detection board 8 may be subjected to a molding process using an insulating material. In this case, the stator is partially applied to the mold shape. A portion shaped so as to engage with the end face of the iron core 1 may be provided, and in this case, higher-precision positioning can be easily obtained.

  Further, here, if both the stator core 1 and the magnetic pole position detection substrate 8 are subjected to a molding process, for example, a concave and convex fitting protrusion may be provided on both fitting portions, Also in this case, highly accurate positioning can be obtained more easily.

  On the other hand, when a mechanism for alignment cannot be provided on the magnetic pole position detection substrate 8 or the stator core 1 as described above, an alignment mechanism is provided on a jig used when the stator winding 2 is applied. Just do it.

  According to the embodiment of FIG. 1, the magnetic pole position detector 9 can be installed at a position very close to the end face of the stator core 1, so that the rotational position is generated by the magnetism of the permanent magnet 10 provided in the rotor 5. As a result, it is not necessary to separately provide a magnet (permanent magnet) for detecting the rotational position, so that the configuration is simplified, and as a result, compared with the prior art described in FIG. In this case, the permanent magnet 10 can be shortened, the amount of the permanent magnet 10 that is an expensive part can be reduced, and the cost can be reduced.

  By the way, in the embodiment described above, the magnetic pole position detection substrate 8 is a single body over the three magnetic pole portions of the stator core 1, but in the embodiment of the present invention, the magnetic pole position detection substrate is connected to each magnetic pole. As shown in FIG. 3, the magnetic pole position detection boards 8 a, 8 b, and 8 c may be provided, and the magnetic pole position detector 9 may be mounted on each to detect the rotational position.

  According to this embodiment, since the three magnetic pole position detectors 9 are mounted on different magnetic pole position detection boards 8a, 8b, and 8c, the magnetic pole position is detected at an arbitrary position on the end face of the stator core 1. As a result, it is possible to mount the device 9 on models having different shapes and dimensions of the end surface of the stator core 1, and improve the mounting position accuracy and share the parts.

1 is a partial side sectional view showing an embodiment of a permanent magnet type synchronous motor according to the present invention. It is the front view and enlarged view by the partial cross section which show one Embodiment of the permanent-magnet-type synchronous motor by this invention. It is a front view by the partial cross section which shows other one Embodiment of the permanent-magnet-type synchronous motor by this invention. It is a partial sectional side view which shows an example of the permanent magnet type synchronous motor by a prior art.

Explanation of symbols

1: Stator core 2: Stator winding 3: Housing 4: End bracket 5: Rotor 6: Rotating shaft 7: Bearing 8: Magnetic pole position detection board 9: Magnetic pole position detector 10: Permanent magnet (for field)

Claims (5)

A permanent magnet type synchronous motor system for rotation control by detecting the magnetic pole position of the rotor by the magnetic sensor,
A magnetic pole position detection board on which the magnetic sensor is mounted ;
The magnetic pole position detection board has a protrusion corresponding to the position of the magnetic pole of the stator core and having a part of the shape substantially the same width as the magnetic pole,
The magnetic sensor is fixed to the protrusion;
The magnetic pole position detection substrate is disposed on the end face of the stator core between the end face of the stator core and the stator winding so that the widths of the protrusion and the magnetic pole are matched. Magnet synchronous motor. The permanent magnet synchronous motor according to claim 1,
The permanent magnet type synchronous motor, wherein the magnetic pole position detection board is fixed by the stator winding . The permanent magnet synchronous motor according to claim 1,
A permanent magnet type synchronous motor, wherein three magnetic sensors are mounted on the magnetic pole position detection board. A permanent magnet type synchronous motor of a type that controls the rotation by detecting the magnetic pole position of the rotor by a magnetic sensor ,
3 magnetic pole position detection boards
The three magnetic pole position detection boards have a part of the shape substantially the same width as the magnetic poles of the stator core,
The magnetic sensor is mounted on each of the three magnetic pole position detection substrates,
Each of the three magnetic pole position detection substrates is disposed between the end face of the stator core and the stator winding at the position of each magnetic pole of the stator core. Electric motor. A permanent magnet type synchronous motor of a type that controls the rotation by detecting the magnetic pole position of the rotor by a magnetic sensor,
A magnetic pole position detection board mounted so that the magnetic sensor is disposed at the magnetic pole position of the stator core;
The magnetic pole position detection substrate has a planar shape substantially the same as the shape of the end face of the stator core,
The magnetic pole position detection board is arranged between the end face of the stator core and the stator winding so that the shape of the end face of the stator core and the magnetic pole position detection board is matched to the end face of the stator core. A permanent magnet type synchronous motor characterized by that.

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