JPH1132462A - Permanent magnet motor and elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly set the mounting position of a permanent magnet and that of a magnetic pole position detection means and to facilitate assembly, by providing a slit for a rotor yoke, arranging the magnetic pole of the permanent magnet along the slit, and providing a sensor that reacts according to the shape of iron while it opposes the slit. SOLUTION: A sensor 6 is provided at the tip of a stator frame 2, and angle information 7 is recorded on the outer-periphery surface of a rotor back yoke 9 opposite to the sensor 6. A permanent magnet is provided on the inner- periphery surface of the rotor back yoke 9. Also, a slit 71 is provided at the rotor back yoke 9 and a permanent magnet is provided by matching a boundary 31 of the magnetic pole of the permanent magnet 3 to the slit 71. The sensor 6 for detecting the slit 71 is provided on a stator frame, thus detecting the magnetic pole boundary of the permanent magnet. With this structure, the magnetic pole boundary position of the permanent magnet can be provided at a specific position, thus detecting the magnetic pole boundary position accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet motor, and more particularly, to a structure of a permanent magnet motor to be incorporated in a traction machine suitable for being disposed in an elevator shaft.

[0002]

2. Description of the Related Art A permanent magnet motor having an epicyclic rotor,
A motor having a permanent magnet provided inside the rotor and a groove for the permanent magnet and having a rotor yoke corresponding to the groove on the rotor yoke side is described in Japanese Patent Application Laid-Open No. 7-147747. I have.

[0003]

In the prior art, an axially long groove having a circular cross section is provided at the boundary between adjacent magnetic poles of a permanent magnet attached to a rotor, and the groove is fitted to a hub of the rotor. A projection is provided. However, in the conventional example, although the position of the magnetic pole of the permanent magnet can be specified, no means for extracting the magnetic pole detection signal is described.

For example, as described in Japanese Patent Application Laid-Open No. 8-191554, a rotation speed detecting means is provided by providing a rotation speed detecting permanent magnet on the outer peripheral portion of a rotor and facing a magnetic sensor to the permanent magnet. There are examples. Even if this configuration is simply combined with the previous embodiment, the rotation speed can be detected, but the magnetic pole position cannot be specified.

[0005] An object of the present invention is to uniformly set a mounting position of a permanent magnet and a mounting position of a magnetic pole position detecting means.
Accordingly, it is an object of the present invention to provide a permanent magnet motor that can be easily assembled.

[0006]

Means for Solving the Problems A rotor yoke is provided with a slit, and the magnetic poles of the permanent magnet are arranged along the slit.
The above problem is solved by providing a sensor that responds according to the shape of iron, for example, an eddy current type magnetic pole position detector, facing the slit.

[0007]

1 and 2 show a motor according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of an upper half surface taken from a rotating shaft of a motor according to an embodiment of the present invention.

As shown in FIG. 1, in this embodiment, the permanent magnet 3 is provided on the inner surface of the rotor back yoke 9 in the cylindrical portion of the cup-shaped rotor 1. A stator core 5 wound with four coils is arranged to face the permanent magnet 3, and the stator core 5 is fixed to the stator frame 2. The stator frame 2 rotatably holds the rotor 1 by bearings 8 and maintains a gap between the stator core 5 and the permanent magnet 3.

Further, at the tip of the stator frame 2,
A sensor 6 is provided, and angle information 7 is recorded on the outer peripheral surface of the rotor back yoke 9 so as to face the sensor 6. FIG. 2 describes only parts not described in FIG. FIG. 2 (1) shows the rotor of FIG. 1 cut in a circumferential direction.

As described above, the permanent magnet is provided on the inner peripheral surface of the rotor back yoke 9, and FIG. 2 (2) is an enlarged view of a part of the permanent magnet. A slit 71 is provided in the rotor back yoke 9, and a permanent magnet is provided in the slit 71 so as to align the magnetic pole boundary 31 of the permanent magnet 3.
As shown in FIG. 1, the sensor 6 capable of detecting the slit 71 is provided on the stator frame, and thereby the magnetic pole boundary of the permanent magnet is detected. Therefore, by adopting such a structure, the magnetic pole boundary position of the permanent magnet can be provided at a specific position, and the magnetic pole boundary position can be correctly detected, so that the phase switching of the permanent magnet motor can be easily and accurately performed. There is an effect that it can be realized.

When an eddy current displacement sensor is used as the sensor 6, for example, a change in magnetic resistance due to the slit can be detected by the sensor, and the slit position can be detected.

FIG. 3 shows an embodiment of an elevator traction machine using a motor according to the embodiment of the present invention.

Parts not described with reference to FIGS. 1 and 2 will be described. The shaft of the rotor 1 is extended, and the sheave 10 is fixed to the rotor. A sensor 6 is provided on the outer periphery of the rotor 1, and the motor and sheave are rotatably supported by the stator frame 2 and the bearing pedestal 11. You. According to this embodiment, the sheave 10 is freely rotated by a permanent magnet motor.

FIG. 4 shows the overall structure of an elevator using a motor according to an embodiment of the present invention.

The traction machine 17 described with reference to FIG. 3 is disposed above the hoistway 21, and the rope 12 is hung on a sheave of the traction machine 17. One end of the rope 12 is connected to the rope via the pulley 15 under the car 22. The other end of the rope 12 is similarly fixed to the top of the hoistway with another rope stop 19 via a pulley 18 on the counterweight 16 via a stop 19. The car 22 is guided by the car rail 20 so as not to shift in the horizontal direction, and the counter weight 16 is guided by the counter weight rail 23 so as not to shift in the horizontal direction.

Power is supplied to the permanent magnet motor and brake of the traction machine 17 by a control panel (not shown), and the operation thereof is controlled. The permanent magnet motor rotates the sheave and drives the rope to move the car up and down to the destination floor. The brake holds the sheave when the car stops and ensures that the car stops at the predetermined floor.

According to this embodiment, the traction machine 1
2 can be made thinner and smaller in diameter, so that the layout plan in the hoistway is easy, and since the traction machine 12 is small and lightweight, it is easy to handle and installation work is easy. By employing the permanent magnet motor of the embodiment of the present invention, the magnetic pole position detection signal can be obtained with high accuracy and at low cost, so that the cost of the system itself can be reduced, and the speed fluctuation can be suppressed, so that the vibration of the car can be reduced. It is possible to obtain a less comfortable elevator. FIG. 5 shows a motor according to another embodiment of the present invention. FIG. 3 is an enlarged view of a part of the cross section of the motor as in FIG.

Only the parts different from FIG. 2 will be described. The permanent magnet 3 is provided inside the rotor back yoke 9 (the lower side in the figure), and the rotor back yoke 9 itself has projections 7 on its outer peripheral surface.
2, a projection 32 is provided on the inner peripheral surface, and this projection is provided at the same location inside and outside. The permanent magnet 3 is fixed with the boundary between the magnetic poles of the permanent magnet aligned with the protrusion 32 of the rotor back yoke 9. Further, as shown in FIG. 1, a sensor 6 capable of detecting the protrusion 72 of the rotor back yoke 9 is provided on the stator frame, thereby detecting the magnetic pole boundary of the permanent magnet. Therefore, by adopting such a structure, the magnetic pole boundary position of the permanent magnet can be provided at a specific position,
Since the magnetic pole boundary position can be correctly detected, there is an effect that the phase switching of the permanent magnet motor can be easily and accurately realized.

If an eddy current displacement sensor is used as the sensor 6, for example, a change in magnetic resistance due to the slit can be detected by the sensor, and the slit position can be detected.

In the above, an example in which a gap change is detected by a sensor as a magnetic pole position has been described. However, in order to accurately detect the number of rotations of a motor, it is necessary to simultaneously generate many pulse signals in one rotation. Can also. For example, a magnetic material may be provided on the outer periphery of the rotor back yoke, and a magnetic pole signal and a pulse signal may be recorded thereon, and these may be detected by a magnetic sensor. The magnetic sensor can be realized by a magnetoresistive element whose resistance changes due to magnetism. At this time, in order to identify the relationship between the inner surface of the rotor back yoke and the magnetic pole boundary position of the permanent magnet, slits and protrusions are provided, and the slits and protrusions are used as triggers to write a magnetic pole signal to a magnetic material. The same effects as those of the previous embodiment can be obtained.

An optical sensor can be used as the sensor. Also in this case, if the same manufacturing method as the magnetic method is used,
A similar magnetic pole signal can be set.

Since the above-mentioned pulse signal is created on the rotor back yoke having a long circumference, the recording pitch of the pulse itself can be increased, and the recording accuracy of the pulse itself can be improved.

[0023]

According to the present invention, the mounting position of the permanent magnet and the mounting position of the magnetic pole position detecting means are set uniformly, so that a permanent magnet motor which is easy to assemble and can detect the magnetic pole position with high accuracy can be obtained. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a permanent magnet motor according to an embodiment of the present invention.

FIG. 2 is a sectional view of a permanent magnet motor according to an embodiment of the present invention.

FIG. 3 is an external view of an elevator traction machine using a permanent magnet motor according to an embodiment of the present invention.

FIG. 4 is an external view of an elevator using the permanent magnet motor according to the embodiment of the present invention.

FIG. 5 is a sectional view of a permanent magnet motor according to another embodiment of the present invention.

[Explanation of symbols]

1 ... rotor, 3 ... permanent magnet, 4 ... coil, 5 ... core, 6
... Sensor, 7 ... Angle information, 9 ... Rotor back yoke.

Continued on the front page (72) Inventor Mitsuhiro Nemoto 1070 Ma, Hitachinaka City, Ibaraki Prefecture Inside the Mito Plant of Hitachi, Ltd. (72) Inventor Takanori Nakata 1070 Ma, Hitachinaka City, Ibaraki Prefecture Inside Mito Plant, Hitachi, Ltd. (72) Inventor Shoji Kitamura 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd.

Claims (6)

[Claims] A rotor having a permanent magnet, wherein the rotor has a cylindrical shape and is of an abduction type permanent magnet motor disposed outside a stator, wherein the permanent magnet is a cylindrical portion of the rotor; Provided at a specific position by a specific mechanism for determining the magnetic pole position on the inner surface of the rotor, an information recording unit outside the rotor, and a detector for extracting information in a non-contact manner with respect to the information recording unit, A permanent magnet motor, wherein the output signal has the same phase as the position of the induced voltage generated in the one-phase coil. 2. A magnetic pole position specifying mechanism and an information recording section are shared by a slit which is long in an axial direction and short in a circumferential direction, and a detector outputs a signal corresponding to a gap change caused by the slit.
2. The permanent magnet motor according to claim 1, wherein the slits are fixed by aligning the boundaries of the magnetic poles of the permanent magnet. 3. The magnetic pole position specifying mechanism and the information recording section are projections that are long in the axial direction and short in the circumferential direction, and are fixed by contacting the boundary of the magnetic pole of the permanent magnet with the projection inside the cylinder of the rotor. 3. The permanent magnet motor according to claim 2, wherein a signal corresponding to a gap variation caused by the protrusion on the outer peripheral portion of the rotor is output. 4. The permanent magnet motor according to claim 1, wherein information is recorded magnetically. 5. The permanent magnet motor according to claim 1, wherein the information is recorded optically. 6. A rope type elevator in which a counterweight and a car are connected via a rope, the rope is driven by a traction machine, and the car is moved up and down. An elevator comprising a sheave directly connected to a rotor of the permanent magnet motor described in the above.