JP3632721B2 - Permanent magnet synchronous motor - Google Patents

Description

BACKGROUND OF THE INVENTION
The present invention relates to a permanent magnet synchronous motor that requires high performance in accuracy, speed, and responsiveness among motors used in semiconductor manufacturing apparatuses and FA equipment, and has small ripples and losses.
[0002]
[Prior art]
When a permanent magnet is used for an electric motor, it is known to obtain a high thrust with a compact configuration, and various structures are considered. A general electric motor includes a permanent magnet in a rotor and a coil wound around an armature core of a stator. However, with this structure, high-performance permanent magnets are being developed today. However, although the torque can be increased, the iron loss and cogging torque are also increased. In order to solve this problem, an improved coil winding method has been developed and disclosed in Japanese Patent Application Laid-Open No. 63-154051. This technique will be described with reference to the drawings.
FIG. 6 is a front sectional view of a conventional permanent magnet type synchronous motor, and FIG. 7 is a winding configuration diagram of a stator coil. This motor is a three-phase, six-pole rotary synchronous motor, and the number of slots in each phase is one. Therefore, 18 slots # 1 to # 18 are formed in the armature core 6 at equal intervals in the circumferential direction. When the coil wound around this is a coil having a lower coil side 81 and an upper coil side 91 as an example, the lower coil side 81 is embedded in the lower side in the slot # 16, and the upper coil side 91 is It is buried above the slot 3 on the right of the three. In the case of another coil having a lower coil side 82 and an upper coil side 92, the lower coil side 82 is embedded in the lower side in the slot # 1, and the upper coil side 92 is positioned on the upper side of the three right slot # 4. The coils having the same shape are wound in the same manner and embedded in other slots, and are connected in series to form a U-phase coil. The V-phase coil and the W-phase coil are also wound in the same manner as the U-phase coil, and are embedded in a slot shifted by one. A wiring method is selected for the three-phase coil as necessary, and a three-phase motor is formed. As shown in FIG. 6, six permanent magnets 4 are fixed to the surface of the rotating shaft 2 and are magnetized so that the adjacent permanent magnets have different polarities.
[0003]
[Problems to be solved by the invention]
However, according to the above prior art, there are the following problems. That is, since the upper coil side of each coil is disposed in the air gap and is integrated with the other lower coil side embedded in the slot, the coil end interferes with the coil end of the other coil, and a predetermined winding It was not easy to configure.
In addition, although the upper coil side and the lower coil side are part of the same coil, the cross-sectional shapes are different, so that there is a drawback that the workability is extremely poor with the positioning work when winding.
Furthermore, since this work is required, the coil wound around the air gap tends to be unaligned, and torque ripples are generated when the motor is driven, causing various adverse effects on the driven system such as rotational ripples. There was a problem of bringing.
If the coil end is lengthened in order to improve the workability, the copper loss of the coil is increased and the efficiency of the motor is lowered, and either workability or efficiency must be sacrificed.
As described above, the conventional method of winding the coil has been problematic due to various problems caused by the position of the coil.
[0004]
[Means for Solving the Problems]
The present invention has been made to eliminate these drawbacks, and an object of the present invention is to provide a permanent magnet type synchronous motor that requires high performance in accuracy, speed, and responsiveness, and has small ripple and loss.
Therefore, the present invention provides a plurality of teeth having a pole shoe at the tip and a stator having an upper coil and a lower coil connected in series to an armature core having an opening, and a multipole through the stator and an air gap. the permanent magnet is Ri Do from the anchored mover, in the air gap near Ru permanent magnet synchronous motor of the coil of the stator is the tooth tip, the upper coil the teeth coaxial with a coreless The lower coil is concentratedly wound around the teeth.
In addition, as a modification, the teeth have a substantially constant width to the tip, the lower coil and the upper coil are wound so that the number of turns and the wire diameter are different, these are used as a rotary electric motor, It was an electric motor.
Furthermore, as a method for manufacturing a stator of a permanent magnet type synchronous motor, at least the upper coil is wound in advance and then attached to the stator.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In this way, winding work becomes easy, the upper coil can be positioned and fixed with high accuracy, and the coil end can be shortened, thus providing a low-cost, high-efficiency, high-precision motor. You will be able to do it.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view of a permanent magnet type synchronous motor showing a first embodiment of the present invention, and FIG. In the figure, reference numeral 1 denotes a rotor, which includes a rotary shaft 2 rotatably supported by a bearing (not shown), a magnetic rotor core 3 fixed to the outer periphery of the rotary shaft 2, and a plurality of circumferentially equal intervals. The permanent magnet 4 has a magnetic pole and is fixed to the outer periphery of the rotor core 3. Reference numeral 5 denotes a stator, and teeth 7 are formed at equal intervals in the circumferential direction on the inner diameter side, an armature core 6 made of a magnetic material, a lower coil 8 wound around the teeth 7, and coaxial with the teeth 7. The upper coil 9 is fixed to the tip of the tooth 7 so as to be. The teeth 7 extend from the annular portion of the armature core 6 toward the center of the electric motor, and the width is wide at the tip to form a pole shoe. The number of poles of the permanent magnet 4 provided in the rotor 1 is 14 and is magnetized in the radial direction. The number of teeth 7 of the stator 5 is 12, and the lower coil 8 is wound around each. Therefore, this electric motor is a three-phase 14-pole 12-slot motor, and the number of slots per phase per pole is 2/7.
[0006]
Next, the coil mounted on the armature core 6 will be described. The coil is composed of an upper coil 9 attached to the air gap and a lower coil 8 wound around the teeth 7 as shown in FIG. 1, and the connection relationship between the teeth 7 and the coil is as shown in FIG. . In the U-phase coil, the upper coil 9 is wound around the teeth # T1, # T2, # T7, and # T8, and the lower coil 8 is fixed to the tip of the same tooth so that the direction of the magnetic flux is the same as shown in FIG. Are connected in series, and have two terminals U and N. The V-phase coil is wound around the teeth # T5, # T6, # T11, and # T12 in the same manner as the U-phase, and is connected in series in the same manner, and has two terminals V and N. The W-phase coil is wound around the teeth # T9, # T10, # T3, and # T4 in the same manner as the U-phase, and is connected in series in the same manner, and has two terminals W and N.
[0007]
Next, description will be given with reference to FIG. 3 showing the positional relationship and shape of the coils. 3A is a cross-sectional view of the tooth 7 on which two coils are mounted. Since the width of the lower coil 8 is wound so that the inner side is in close contact with the teeth 7, the width of the coil cross section for two pieces and the width of the teeth 7 are added. The length is a length obtained by adding the width of the coil cross section for two pieces and the length of the tooth 7 to the gap of the curved portion of the coil. The upper coil 9 has a thin thickness in the longitudinal direction of the tooth 7 so as to be attached to the air gap. However, since the coil is not wound around the tooth 7 and is an air-core coil, the inner side of the coil has a width and a length. Is smaller than that of the lower coil 8, and the outer width and length are slightly smaller than those of the lower coil 8. Moreover, since the cross section of both coils has a difference in the installation space, the lower coil 8 is larger. Since it is wound in this way, both coils are concentrated and winding work becomes easy. At the same time, even if the coil end is included, the length of the coil is much shorter than the conventional one. The copper loss that occurs is small.
[0008]
Next, a second embodiment of the present invention will be described. FIG. 4 is a front sectional view of a permanent magnet type synchronous motor showing a second embodiment of the present invention, and the symbols are the same as those in the first embodiment of FIG. In the figure, the difference from FIG. 1 is that no pole shoe is formed at the tip of the tooth 7. With such a structure, the lower coil 8 can be wound in advance similarly to the upper coil 9, and the lower coil 8 can be wound up to the tip of the teeth 7. For this reason, since the stator 5 can be made small, the iron loss of the armature core 6 can be reduced. Further, since the lower coil 8 can be formed smaller than in the case of the first embodiment, the copper loss can be reduced, and the workability is further improved than in the first embodiment.
[0009]
Next, a third embodiment of the present invention will be described. According to the configuration of the present invention, there is no need to make the number of turns of the opening and the gap the same as in the conventional example. That is, the number of turns or the wire diameter of the upper coil and the lower coil can be freely selected. For example, if the number of turns of the upper coil is increased and the number of turns of the lower coil is reduced, the inductance becomes smaller and the responsiveness becomes better. In addition, since the upper coil and the lower coil are connected in series, the ratio of copper loss generated in each coil is different, and copper loss is minimized by selecting the appropriate number of turns and wire diameter for each coil. can do.
[00010]
Although the rotary type embodiment has been described above, the present invention can be applied to a linear synchronous motor and will be described with reference to the drawings. FIG. 5 is a front sectional view of an essential part of a linear permanent magnet type synchronous motor showing a fourth embodiment of the present invention, which is a three-phase motor having 2/7 slots per pole and phase. In the figure, 11 is a mover, 41 is a permanent magnet, 51 is a stator, 71 is a tooth, 81 is a lower coil, 91 is an upper coil, and there are 18 teeth of the rotary synchronous motor of the first embodiment. This is equivalent to a straight line. Therefore, it goes without saying that the winding method and the number of windings of both coils can be applied to those described in the first to third embodiments.
[00011]
All of the synchronous motors described above have 2/7 slots per pole and phase, but it goes without saying that the numerical values are not limited to those described above in accordance with the spirit of the present invention. In addition, although the rotary type synchronous motor is shown in which an annular permanent magnet is magnetized in the radial direction, the magnetizing direction can be the circumferential direction. Moreover, even if it replaces with an annular | circular shaped permanent magnet and the permanent magnet of the segment divided | segmented into plurality is used, it will not be supported at all.
[00012]
【The invention's effect】
As described above, according to the present invention, since the coil ends of the upper coil and the lower coil do not interfere with each other, winding work is facilitated and productivity is improved, and at the same time, assembly accuracy is improved and torque ripple is improved. Alternatively, the thrust ripple is suppressed to be small, which is suitable for a device to which an electric motor is applied. Moreover, since the length of the conductor used for a coil becomes significantly shorter than before, there is an effect that it is possible to provide an electric motor with low copper loss and high efficiency.
[00013]
[Brief description of the drawings]
FIG. 1 is a front sectional view of a rotary permanent magnet type synchronous motor according to a first embodiment. FIG. 2 is a coil winding configuration diagram. FIG. 3 is an explanatory diagram of a coil. FIG. 5 is a front sectional view of a main part of a linear permanent magnet synchronous motor of a third embodiment. FIG. 6 is a front sectional view of a conventional permanent magnet synchronous motor. 7] Winding diagram of conventional coil 【Explanation of symbols】
1 rotor, 2 rotation axis, 3 rotor core,
4, 41 Permanent magnet, 5, 51 Stator, 6 Armature core,
7,71 teeth, 8,81 lower coil, 9,91 upper coil,
11 Mover

Claims (6)

A plurality of teeth having a pole shoe at the tip, a stator having an upper coil and a lower coil connected in series to an armature core having an opening, and a multipolar permanent magnet are fixed to the stator via an air gap in been Ri Do from the movable element, the air gap near Ru permanent magnet synchronous motor of the coil of the stator is the tooth tip,
The permanent magnet type synchronous motor according to claim 1, wherein the upper coil is air-centered and fixed coaxially with the teeth, and the lower coil is concentratedly wound around the teeth . 2. The permanent magnet type synchronous motor according to claim 1, wherein the teeth have a substantially constant width to the tip. 3. The permanent magnet type synchronous motor according to claim 1, wherein the lower coil and the upper coil have different numbers of turns and wire diameters. 4. The permanent magnet type synchronous motor according to claim 1, wherein the air gap has a cylindrical shape and is a rotary type electric motor. 4. The permanent magnet type synchronous motor according to claim 1, wherein the air gap is a flat motor and is a linear motor. 6. The method for manufacturing a stator of a permanent magnet type synchronous motor according to claim 1, wherein at least the upper coil is wound in advance, and then mounted on the stator.
[0001]

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