A synchronous reluctance motor

Abstract

The utility model introduces a synchronous reluctance motor, including a housing, a stator, a rotor core and a rotating shaft; a rotor punching sheet is evenly spaced around an axial hole with a plurality of annular shaft grooves, the annular shaft grooves include arc, reverse arc, straight bar or multi-section bending; a split pole groove is connected between the ends of two adjacent annular shaft grooves, and a dovetail-shaped interpolar groove is correspondingly arranged on the outer edge of the rotor punching sheet outside each annular shaft groove, and pole shoes are formed on both sides of the outer notch of the interpolar groove. The rotor punching sheet of the utility model has a simple structure, and only a single-layer guide bar is arranged to save a part of the scarce space of the rotor to form an interpolar groove, and the interpolar groove better reduces the cross-axis inductance, and a pole shoe is arranged at the end of the guide bar, and a non-equal length air gap and a pole surface groove are arranged on the outer surface of the pole shoe to solve the problem of poor distribution caused by the single-layer guide bar, and can improve the distribution characteristics of the air gap magnetic flux density. When the motor is running, the rotor core is affected by the alternating magnetic field generated by the stator and the deformation amount is small. The reduced deformation amount can reduce the noise of the motor.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a synchronous reluctance motor. Background Art

[0002] In order to form distributed multi-layer conductive bars, the existing synchronous reluctance motor needs to cut a large number of slits between the conductive bars in the rotor core, so that the interior of the entire rotor core punching sheet presents a hollow structure. Each layer of conductive bars is attached to the underlying structure through a slender magnetic bridge, resulting in more deformation of the conductive bars in the outer layers, making the rigidity of the entire rotor poor. When the motor is running, due to the influence of the alternating magnetic field and torque pulsation, tiny deformations will occur between the numerous conductive bars in the rotor core, causing noise. The complex structure of the rotor core also leads to a very long total tangent length for the core punching sheet processing, a large stamping force is required during the stamping process, and the energy consumption required for motor manufacturing is high. Utility Model Content

[0003] The utility model aims to overcome the deficiencies of the prior art and provide a synchronous reluctance motor with a simple rotor punching structure, which greatly reduces the tangent length of the punching and ensures the overall rigidity of the rotor core.

[0004] The technical solution adopted by the utility model is:

[0005] A synchronous reluctance motor comprises a housing, a stator, a rotor core and a rotating shaft, wherein the stator is installed in the housing, the rotor core is arranged in the stator and an air gap is left between the rotor core and the inner wall of the stator, the rotor core comprises a plurality of rotor punchings stacked concentrically, an axial hole is arranged at the center of the rotor punching, and the rotating shaft is arranged in the axial hole;

[0006] The rotor punching sheet is evenly spaced with a number of annular shaft grooves around the shaft hole, the number of the annular shaft grooves is consistent with the number of motor poles 2P, the shapes of the annular shaft grooves include arc, reverse arc, straight bar or multi-stage bending, the center of the geometric figure formed by the annular shaft grooves is concentric with the shaft hole; an axis hoop is formed between the annular shaft groove and the shaft hole; the ends of two adjacent annular shaft grooves are connected together or separately with a split pole groove, and a split pole groove is connected together to form a two-split salient pole, and a split pole groove is connected separately to form a three-split salient pole; a magnetic bridge is formed between the inner end of the split pole groove and the end of the annular shaft groove, and the outer end points to the circumference of the rotor punching sheet and forms a magnetic bridge with the outer edge of the rotor punching sheet; dovetail-shaped interpolar grooves are correspondingly arranged on the outer edge of the rotor punching sheet outside each annular shaft groove, and pole shoes are formed on both sides of the outer notch of the interpolar groove, and the bottom edge line of the interpolar groove matches the shape of the annular shaft groove; the bottom edge line of the interpolar groove, the annular shaft groove and the area between the split pole grooves at both ends form a guide bar; a pole surface groove is arranged on the outer edge of the rotor punching sheet between two adjacent interpolar grooves.

[0007] Specifically, the setting range of the maximum width angle ω1 of the inter-electrode groove is to between.

[0008] Specifically, the interior of the annular shaft groove is empty or is equipped with a permanent magnet matching the annular shaft groove.

[0009] Specifically, the air gap length δ between the rotor core and the stator is set to be non-equal length, and the air gap length δ gradually increases toward both sides with the d-axis as the center.

[0010] Due to the adoption of the above-mentioned technical solution, the utility model has the following advantages:

[0011] The rotor punching structure of the utility model is simple. Only a single-layer conductor bar is provided to save a part of the scarce space of the rotor to form an inter-pole groove. The inter-pole groove can better reduce the cross-axis inductance Lq. Pole shoes are provided at the ends of the conductor bars, and non-equal length air gaps and pole surface grooves are provided on the outer surfaces of the pole shoes to solve the problem of poor distribution caused by the single-layer conductor bar, which can improve the distribution characteristics of the air gap magnetic flux density. Only a small number of magnetic bridges are provided as supporting structures to connect the various conductor bars. There is no superposition of deformation amounts peculiar to the rotor punching of the existing multi-layer conductor bar type synchronous reluctance motor, which can well maintain the overall rigidity of the rotor punching structure. When the motor is running, the deformation amount of the rotor core affected by the rotating magnetic field of the stator is small. The reduction in deformation amount can reduce the noise of the motor. In addition, compared with the rotor punching of the existing multi-layer conductor bar type synchronous reluctance motor, the utility model saves a large number of tortuous tangents, so that the punching force required for the rotor punching during stamping is greatly reduced. Since the number of rotor punchings required for the motor is large, the electric energy consumed in the motor production process can be significantly saved in accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional schematic diagram of the utility model.

[0013] Figure 2 It is a schematic diagram of a rotor punching sheet with arc-shaped annular shaft grooves of a six-pole two-split salient pole of the utility model.

[0014] Figure 3 It is a schematic diagram of a rotor punching sheet with a straight strip type annular shaft groove of a six-pole two-split salient pole of the utility model.

[0015] Figure 4 It is a schematic diagram of a rotor punching sheet with reverse arc-shaped annular shaft grooves of a six-pole two-split salient pole of the utility model.

[0016] Figure 5 It is a schematic diagram of a rotor punching sheet with arc-shaped annular shaft grooves of a six-pole three-split salient pole of the utility model.

[0017] Figure 6 It is a schematic diagram of a rotor punching sheet with straight strip-type annular shaft grooves of a six-pole three-split salient pole of the utility model.

[0018] Figure 7 It is a schematic diagram of a rotor punching sheet with reverse arc-shaped annular shaft grooves of a six-pole three-split salient pole of the utility model.

[0019] Figure 8 It is a schematic diagram of a rotor punching sheet with multi-section bent annular shaft grooves of a six-pole three-split salient pole of the utility model.

[0020] Fig. 9 It is a schematic diagram of a rotor punching sheet with an arc-shaped annular shaft groove of a two-pole three-split salient pole of the utility model.

[0021] Fig.10 yes Fig. 9 Schematic diagram of the air gap length δ of the structure.

[0022] Fig.11 It is a no-load air gap magnetic flux density distribution diagram of a 4-pole three-split salient pole rotor of the utility model.

[0023] In the figure: 1- housing, 2- stator, 3- rotor punching, 31- shaft hole, 32- guide bar, 33- interpole groove, 34- pole shoe, 35- split pole groove, 36- shaft hoop, 37- ring shaft groove, 38- magnetic bridge, 39- pole face groove, 4- air gap, 5- rotating shaft, d- direct axis, q- quadrature axis, ω1- maximum width angle of interpole groove, δ- air gap length, Φ- magnetic flux lines. DETAILED DESCRIPTION

[0024] The present invention is further explained below in conjunction with the accompanying drawings and embodiments, which should not be used to limit the protection scope of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0025] Combined with Figure 1-11 A synchronous reluctance motor shown includes a housing 1, a stator 2, a rotor core and a rotating shaft 5. The stator 2 is installed in the housing 1. The rotor core is arranged in the stator 2 and an air gap 4 is left between the rotor core and the inner wall of the stator 2. The rotor core includes a plurality of rotor punchings 3 which are stacked concentrically. An axial hole 31 is provided at the center of the rotor punching 3. The rotating shaft 5 is arranged in the axial hole 31.

[0026] The rotor punching 3 is evenly spaced with a number of annular shaft grooves 37 around the shaft hole 31. The number of annular shaft grooves 37 is consistent with the number of motor poles 2P. The shapes of the annular shaft grooves 37 include arc, straight bar or multi-section bending. The center of the geometric figure enclosed by each annular shaft groove 37 is concentric with the shaft hole 31; an axle hoop 36 is formed between the annular shaft groove 37 and the shaft hole 31; the ends of two adjacent annular shaft grooves 37 are connected together or separately with a split pole groove 35, and a split pole groove 35 is connected together to form a two-split salient pole, and a split pole groove 35 is connected separately to form a three-split salient pole; a magnetic bridge 38 is formed between the inner end of the split pole groove 35 and the end of the annular shaft groove 37, and the outer end points to the circumference of the rotor punching 3 and forms a magnetic bridge 38 with the outer edge of the rotor punching 3; a dovetail-shaped inter-pole groove 33 is correspondingly provided on the outer edge of the rotor punching 3 outside each annular shaft groove 37, and the setting range of the maximum width angle ω1 of the inter-pole groove is to Pole shoes 34 are formed on both sides of the outer notch of the interpolar groove 33, and the bottom edge of the interpolar groove 33 matches the shape of the annular shaft groove 37; the area between the bottom edge of the interpolar groove 33, the annular shaft groove 37 and the split pole grooves 35 at both ends forms a guide bar 32; and a pole surface groove is provided on the outer edge of the rotor punching 3 between two adjacent interpolar grooves 33.

[0027] Preferably, the interior of the annular shaft groove 37 is empty or a permanent magnet matching the annular shaft groove 37 is installed.

[0028] Preferably, the air gap length δ between the rotor core and the stator 2 is set to be non-equal length, and the air gap length δ gradually increases toward both sides with the d-axis as the center.

[0029] The utility model adopts a single-layer conductive bar 32 with a relatively wide width, and through cooperation with the pole shoe 34, the non-equal-length air gap 4 and the pole face groove 39, the main magnetic flux is normally conducted along the d-axis magnetic circuit in the rotor core. The pole shoe 34 increases the width of the pole face, so that the main magnetic flux path passing through the air gap 4 can cover most of the rotor surface except for a small range of the q-axis position, and the interpolar groove 33 appears in the area not covered by the main magnetic flux; because the interpolar groove 33 is at the q-axis position, because the rotor of the synchronous reluctance motor needs to form a lower inductance in the q-axis magnetic circuit, the air groove that gradually increases inward from the opening of the interpolar groove 33 appears here just to meet this condition. The pole face groove is set on the rotor pole face to reduce the conduction of the magnetic flux in the shallow layer under the pole face along the circumferential direction, and can limit the magnetic flux from gathering at the front pole shoe 34 when the motor is overloaded, thereby reducing the torque loss.

[0030] On the pole face of the rotor core, the air gap length δ near the d-axis is set as the minimum safety distance, and the air gap length δ gradually increases toward both sides; the function is to improve the distribution characteristics by distributing the magnetic flux density distribution passing through the air gap 4; the function of the pole shoe 34 is to increase the coverage of the pole face, and the function of the unequal width air gap 4 is to reduce the magnetic flux distribution to the pole shoe 34, so that the magnetic flux density of the air gap 4 on the pole face from the position near the d-axis to the position near the q-axis gradually decreases instead of sharply decreasing at the outermost part of the pole face; the air gap length δ at different positions is different, forming an effect of gradually decreasing the magnetic flux distribution from the position near the d-axis to the position near the q-axis. According to the principle of minimum magnetic resistance, the magnetic flux has the characteristic of selecting the path with the minimum magnetic pressure drop. The magnetic permeability μ of the core material such as silicon steel sheet Fe The magnetic permeability μ0 is much larger than that of air, resulting in the magnetic flux density near the d-axis being significantly higher than that on both sides.

[0031] The split-pole slot 35 is the key to forming the conductive bar 32. One end of each of the two adjacent conductive bars 32 is close to each other at the d-axis position. The split-pole slot 35 serves as a magnetic isolation slot. A magnetic bridge 38 is provided at the outer end of the split-pole slot 35. The split-pole slot 35 prevents the magnetic flux from being conducted along the q-axis magnetic circuit, which can reduce Lq and further increase the salient pole ratio of the rotor. A split-pole slot 35 is connected between the ends of two adjacent annular shaft slots 37 to form a two-split salient pole rotor. The two sides of the split-pole slot 35 can carry a magnetic potential difference, forming a two-level magnetic potential on the rotor surface. Between the ends of the two adjacent annular shaft slots 37, a magnetic potential difference is formed. A three-split salient pole rotor is formed by connecting a split pole slot 35 respectively. The magnetic potential difference generated between the three parts forms a three-level magnetic potential on the rotor surface. The middle part is the neutral magnetic potential area. The neutral magnetic potential area of ​​each pole axis is integrated at the shaft hoop 36 and the rotating shaft 5. When the motor is running, the neutral magnetic potential area of ​​the pole axis is not magnetized, and can absorb part of the main magnetic flux to be conducted inward through the silicon steel at the shaft hoop 36 and the steel and iron rotating shaft 5 with good magnetic conductivity, so that the magnetic flux conducted through the conductive bar 32 is reduced. Therefore, the width of the conductive bar 32 of the three-split salient pole rotor is narrower than that of the two-split salient pole rotor. Fig.11 As shown, the figure shows the no-load air gap 4 magnetic flux density distribution of the 4-pole three-split salient pole rotor embodiment of the utility model.

[0032] The ring shaft groove 37 prevents the magnetic flux on the conductive bar 32 from being conducted along the q-axis magnetic circuit through the shaft hoop 36 and the steel or iron rotating shaft 5 with good magnetic conductivity. The leakage magnetic flux needs to pass through the ring shaft groove 37 twice to pass through the shaft. The magnetic bridge 38, which serves as the supporting structure of the entire punching sheet, is indispensable. The ring shaft groove 37 is divided into slot segments equal to the number of motor poles 2P. Permanent magnets are inserted into the ring shaft groove 37. Ordinary ferrite, samarium cobalt ferrite or neodymium magnet steel can be selected. The ring shaft groove 37 can also be left empty or injected with non-magnetic fillers to reinforce the rotor. Permanent magnets of different materials inserted into the ring shaft groove 37 respectively result in different constant magnetic field intensities on the rotor, and motors with different back electromotive force amplitudes are obtained through armature reaction. The motor with the ring shaft groove 37 empty or injected with non-magnetic fillers does not generate back electromotive force, and the motor torque only has a reluctance torque component.

[0033] The parts not described in detail in this utility model are prior art.

[0034] The embodiments selected in this article for the purpose of disclosing the utility model are currently considered to be suitable, but it should be understood that the utility model is intended to include all changes and improvements of the embodiments that belong to the scope of the present concept and utility model.

Claims

1. A synchronous reluctance motor, comprising a housing, a stator, a rotor core and a rotating shaft, wherein the stator is mounted in the housing, the rotor core is arranged in the stator and an air gap is left between the rotor core and the inner wall of the stator, the rotor core comprises a plurality of rotor punchings stacked concentrically, an axial hole is arranged at the center of the rotor punching, and the rotating shaft is arranged in the axial hole; characterized in that: The rotor punching sheet is evenly spaced with a number of annular shaft grooves around the shaft hole, the number of the annular shaft grooves is consistent with the number of motor poles 2P, the shapes of the annular shaft grooves include arc, reverse arc, straight bar or multi-stage bending, the center of the geometric figure formed by the annular shaft grooves is concentric with the shaft hole; an axis hoop is formed between the annular shaft groove and the shaft hole; the ends of two adjacent annular shaft grooves are connected together or separately with a split pole groove, and a split pole groove is connected together to form a two-split salient pole, and a split pole groove is connected separately to form a three-split salient pole; a magnetic bridge is formed between the inner end of the split pole groove and the end of the annular shaft groove, and the outer end points to the circumference of the rotor punching sheet and forms a magnetic bridge with the outer edge of the rotor punching sheet; dovetail-type interpolar grooves are correspondingly arranged on the outer edge of the rotor punching sheet outside each annular shaft groove, and pole shoes are formed on both sides of the outer groove of the interpolar groove; the bottom edge line of the interpolar groove matches the shape of the annular shaft groove; the bottom edge line of the interpolar groove, the annular shaft groove and the area between the split pole grooves at both ends form a guide bar; a pole surface groove is arranged on the outer edge of the rotor punching sheet between two adjacent interpolar grooves.

2. The synchronous reluctance motor according to claim 1, characterized in that: The setting range of the maximum width angle ω1 of the inter-electrode groove is to 3. The synchronous reluctance motor according to claim 1, characterized in that: The interior of the annular shaft groove is empty or is equipped with a permanent magnet matching the annular shaft groove.

4. The synchronous reluctance motor according to claim 1, characterized in that: The air gap length δ between the rotor core and the stator is set to be non-equal length, and the air gap length δ gradually increases toward both sides with the d axis as the center.

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