JPH0711859U - Permanent magnet type synchronous motor rotor - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a rotor of a permanent magnet type synchronous motor for maintaining the strength of a rotor core and maintaining a gap. [Structure] A rotor core 31 made of laminated electromagnetic steel sheets and two blades with a gap in the inner diameter of an armature 1 provided with a multi-phase / multi-pole winding 21 provided in a status lot 2 provided in a core made of laminated electromagnetic steel sheets. Groove 33 in the direction of the normal to prevent magnetic flux leakage, a rectangular field permanent magnet is fitted in the slot, and a salient pole portion 34 is formed on the upper surface of the field permanent magnet. In the rotor of the electric motor, the slot is divided into two parts 32a and 32b in the left and right at the central part, and the salient pole part 34 is formed.
And a bridge 35 that bridges the rotor core 31 and
The field permanent magnet is divided into 2 into 4a and 4b, and a slot 3
2a and 32b are fitted. Or the central part of the slot
Dovetail grooves are provided on the top and bottom, and the non-magnetic dovetail key bridges between the grooves.

Description

[Detailed description of the device]

[0001]

[Industrial field of application]

 The present invention relates to a rotor structure of a permanent magnet type synchronous motor, and more particularly to a rotor structure capable of withstanding high speed rotation.

[0002]

[Prior art]

 As a rotor of a conventional permanent magnet type synchronous motor, as shown in Fig. 5, an inner diameter of an armature 1 in which a multi-phase / multi-pole winding 21 is provided in a status lot 2 provided in a core made of laminated electromagnetic steel plates. In the rotor core 31, which is made of laminated electromagnetic steel sheets, a groove 33 in the normal direction is provided on both blades to prevent leakage flux, and is slightly narrower than the pole pitch by making it orthogonal to the normal direction of the rotor core 31. There is one in which a rectangular slot 32 having a width is provided, an integral rectangular field magnet 4 is fitted in the slot 32, and the upper surface of the field permanent magnet 4 serves as a salient pole portion 34.

[0003]

[Problems to be solved by the device]

However, in the prior art, since the salient pole portions 34 adjacent to each other on the outer diameter side are joined only by the remaining portion of the rotor core left uncut at the top of the groove 33, there is a problem in strength and gap change. Fig. 6 shows an example of FEM (finite element method) analysis of the amount of deformation and stress with respect to the centrifugal force of a conventional rotor. When the rotor rotates at high speed, the outer diameter of the salient pole portion is As a result, the outermost part bulges up to 33 microns at maximum, and stress concentrates near the top of the groove 33, resulting in 37 KGf / mm ² . That is, there were problems in both the strength of the rotor core and the change in the gap during high-speed rotation. It is an object of the present invention to provide a rotor of a permanent magnet type synchronous motor for maintaining the strength of a rotor core and maintaining a gap during high speed rotation.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a laminated electromagnetic steel sheet is provided with an air gap in the inner diameter of an armature 1 in which a multi-phase / multi-pole winding 21 is provided in a status lot 2 provided in a core made of laminated electromagnetic steel sheet. The rotor core 31 is provided with grooves 33 in the normal direction for preventing magnetic flux leakage on both blades, and rectangular slots 32 having a width slightly narrower than the pole pitch are provided orthogonal to the normal direction of the rotor core 31. In a rotor of a permanent magnet type synchronous motor in which a rectangular field permanent magnet is fitted in the slot 32 and a salient pole portion 34 is formed on the upper surface of the field permanent magnet 4, the slot is left and right at the center. A bridge 35 that bridges the salient pole portion 34 and the rotor core 31 is divided into 32a and 32b, and the field permanent magnet is divided into 4a and 4b. Slots 32a and 32, respectively fit in b. Alternatively, dovetail grooves 51, 51 are provided at the center and upper and lower portions of the slot 32, and the upper and lower dovetail grooves 51, 51 are bridged by a non-magnetic dovetail key 5.

[0005]

[Action]

 The salient pole portion 34 is bridged with the rotor core 31 at the central portion.

[0006]

【Example】

 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the present invention. The multi-phase / multi-pole winding 21 is provided in the status lot 2 provided on the core made of laminated electromagnetic steel plates, and the same armature 1 as the conventional one is configured. A rotor core 31 made of laminated electromagnetic steel sheets is provided in the inner diameter of the armature 1 with a space therebetween, and is made orthogonal to the normal direction, and is provided with rectangular slots 32a, 32b having a width slightly narrower than half the pole pitch. Between the slots 32a and 32b, a bridge 35 is formed by leaving the rotor core 31 with a width t left in the normal direction. A groove 33 is provided to prevent the remaining magnetic flux leakage. In the rotor core 31, the salient pole portion 34 and the rotor core 31 are connected by a, b, and c portions and integrated, and the width t of the fridge 35 maintains mechanical strength and the magnetic path is saturated electromagnetically. It has a value like this. Field permanent magnets 4a and 4b, which have the same thickness and width as the slots 32a and 32b and are magnetized in the radial direction so that they have the same pole, are fitted in the slots 32a and 32b.

FIG. 2 shows an example of FEM analysis of the amount of deformation and stress when the present invention is applied, and the assumption of calculation is the same as that of the conventional example shown in FIG. Conventionally, the maximum deformation of the salient pole outer diameter was 33 microns, but by applying the present invention, it was reduced to 8 microns, and the stress near the top of the groove was 37 K Gf / mm ² . That of 21 KGf / mm ² .

FIG. 3 is a sectional view showing a second embodiment. The slot 32 is provided in the same manner as the conventional one, and the dovetail groove 51 is provided in the central portion and the upper and lower portions of the slot 32. In the dovetail groove 51, a non-magnetic dovetail key 5 having dovetails at the upper and lower ends is fitted to bridge the salient pole portion 34 and the rotor core 31.

FIG. 4 is a perspective view showing a third embodiment. The rotor core 31 of the embodiment is axially divided into four blocks A to D. In the slots 32Aa, 32Ab, 32Ba, 32Bb, 32Ca, 32Cb, 32Da, 32Db of each block, field permanent magnets 4Aa, 4Ab, 4Ba, 4Bb, 4Ca, 4Cb having a length equal to the length of each block are provided. 4Da and 4Db are fitted, and the centers of the slots of the blocks are laminated in the axial direction with the phase sequentially shifted by an angle α. By doing so, step-like rotor skew is applied.

[0010]

[Effect of device]

 As described above, according to the present invention, by bridging the salient poles at the center of the rotor core, stress concentration and deformation due to centrifugal force are mitigated, rotor strength is improved, and permanent magnets that withstand high-speed rotation are provided. It is possible to realize a rotor of a synchronous motor. In addition, in the second embodiment, the leakage flux can be reduced by using the bridge as a key of a non-magnetic material, and the motor efficiency and the centrifugal force strength performance can be improved at the same time.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 FEM calculation results of rotor deformation amount and stress in the present invention

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a perspective view showing a third embodiment of the present invention.

FIG. 5 is a sectional view showing a conventional technique.

FIG. 6 FE of rotor deformation amount and stress in the conventional technique
M calculation result

[Explanation of symbols]

1 armature, 2 status lots, 21 windings, 3
Rotor, 31 rotor core, 32, 32a, 32b, 3
2Aa, 32Ab, 32Ba, 32Bb, 32Ca, 3
2Cb, 32Da, 32Db slot, 33 groove, 3
4 salient poles, 35 bridges, 4, 4a, 4b, 4A
a, 4Ab, 4Ba, 4Bb, 4Ca, 4Cb, 4D
a, 4Db field permanent magnet, 5 dovetail key, 51
Dovetail groove

Claims (4)

[Scope of utility model registration request] 1. A laminated electromagnetic field having a multi-phase / multi-pole winding (21) provided in a status lot (2) provided in a core made of laminated electromagnetic steel sheets, with a gap provided in the inner diameter of an armature (1). A rotor core (31) made of a steel plate is provided with grooves (33) in the normal direction to prevent magnetic flux leakage on both blades, and the width is slightly narrower than the pole pitch so as to be orthogonal to the normal direction of the rotor core (31). A plurality of rectangular slots (32) are provided, a rectangular field permanent magnet (4) is fitted in the slots (32), and a salient pole portion (34) is formed on the upper surface of the field permanent magnet (4). In the rotor of the permanent magnet type synchronous motor described above, the slot (3
2a, 32b), a bridge bridging the salient pole portion (34) and the rotor core (31), and a field permanent magnet (4a, 4b) obtained by dividing the field permanent magnet into two. Permanent magnet type synchronous motor rotor. 2. The rotor of a permanent magnet type synchronous motor according to claim 1, wherein the bridge is formed by a rotor core left uncut in the central portion of the slot (32). 3. The dovetail groove (51) provided in the central portion of the slot (32) and the non-magnetic dovetail key (5) fitted in the dovetail groove (51). The rotor of the permanent magnet type synchronous motor according to 1. 4. The rotor core (31) is divided into a plurality of blocks in the axial direction, and a field permanent magnet having a length equal to the length of each block is fitted into the slot of each block.
2. The rotor skew is provided by stacking axially the center of the slot of each block by a predetermined angle and sequentially stacking the phases.
4. A rotor for a permanent magnet synchronous motor according to any one of items 1 to 3.