Shift type built-in slot-increased permanent magnet rotor

Abstract

The utility model relates to a built-in type permanent magnet rotor of shifting type, and relates to the technical field of motor, and the rotor includes rotor core, be equipped with a plurality of permanent magnet unit on rotor core, each permanent magnet unit surrounds the axial symmetry of rotor core, permanent magnet unit includes two transverse magnetic steel groups and two pairs of oblique magnetic steel of one word type, each transverse magnetic steel group is divided into two rows outward and inward along the radial, is provided with a plurality of one word type magnetic steel of different width in each row, two pairs of oblique magnetic steel are arranged at intervals from inside to outside along the radial of rotor core, each pair of oblique magnetic steel is symmetrically arranged relative to d axle and is arranged shape is narrow mouth department of eight character shape of inwards, two transverse magnetic steel groups are arranged in the eight character narrow mouth department of oblique magnetic steel respectively, and the part of rotor core outside the radial outer side of the first U type magnetic steel group is provided with oval recess, and the outer end surface of this rotor core part is provided with two semicircular recesses, the rotor provided by the utility model can reduce motor noise and torque fluctuation.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a technology for a shift-type built-in slotted permanent magnet rotor. Background Technology

[0002] Built-in permanent magnet synchronous motors have a small effective air gap, resulting in a significant impact from cogging torque. In speed control systems, when the frequency of the motor torque coincides with the mechanical resonant frequency of the stator or rotor, the vibration and noise generated by the cogging torque are significantly amplified, also affecting low-speed performance and positioning accuracy. Furthermore, drawbacks such as a narrow high-speed constant power range and poor reliability make it difficult to meet requirements.

[0003] Cogging torque, also known as reluctance torque, is a fatal flaw in speed control systems used in automated and mechatronic applications. Various methods to reduce motor torque ripple, such as fractional slot, auxiliary slot, auxiliary tooth, skewed slot, skewed pole, closed slot, and magnetized slot wedge methods, each have their advantages and disadvantages, but none are truly effective in eliminating cogging. Skewed slots or skewed poles are the most commonly used methods to reduce torque ripple, but these methods affect the air gap magnetic induction intensity and flat top width of square wave motors. Furthermore, stator skew complicates the manufacturing process and structure, reduces the stator slot area, lowers output power, and increases copper losses. Both skewed slots and skewed poles reduce output power and complicate the motor's manufacturing process and structure, increasing manufacturing costs. Utility Model Content

[0004] In view of the defects existing in the prior art, the technical problem to be solved by this utility model is to provide a displacement-type built-in slotted permanent magnet rotor that can reduce motor noise and torque fluctuation.

[0005] To solve the above-mentioned technical problems, this utility model provides a displacement-type built-in slotted permanent magnet rotor, including a rotor core, on which multiple permanent magnet units are provided, and each permanent magnet unit is symmetrically arranged around the axis of the rotor core. The permanent magnet unit includes two transverse magnet groups and two pairs of straight oblique magnets. Each transverse magnet group is divided into inner and outer rows along the radial direction. Each row is provided with multiple straight magnets of different widths. A separator core is provided between each straight magnet. The two pairs of oblique magnets are arranged at intervals from the inside to the outside along the radial direction of the rotor core. Each pair of oblique magnets is symmetrically arranged relative to the d-axis and is arranged in a figure-eight shape with the narrow opening facing inward. Air permanent magnet slots are provided at both the inner and outer ends of each oblique magnet. The two transverse magnet groups are respectively arranged in the narrow opening of the figure-eight shape of the oblique magnets, so that the two transverse magnet groups and the two pairs of oblique magnets form two U-shaped magnet groups. In each permanent magnet unit, the rotor core portion radially outer of the first U-shaped magnet group is provided with an elliptical groove, and the outer end face of the rotor core portion is provided with two semi-circular grooves. The elliptical groove and the two semi-circular grooves are symmetrically arranged relative to the d-axis.

[0006] The present invention provides a displacement-type built-in slotted permanent magnet rotor, which is equipped with a double-layer U-shaped magnet group and uses horizontally different-width straight magnets to form displacement block permanent magnet poles with the rotor core, forming an asymmetrical displacement on the d-axis. Grooves are opened on the rotor core to reduce armature reaction demagnetization and magnetic field distortion, which can improve the air gap magnetic flux density waveform, effectively reduce motor noise and torque fluctuation, significantly reduce the fluctuation of the motor's composite torque, suppress static and dynamic armature reaction, and improve the overall performance of the motor. Attached Figure Description

[0007] Figure 1 This is a radial cross-sectional schematic diagram of the shift-type built-in slotted permanent magnet rotor according to an embodiment of the present invention. Detailed Implementation

[0008] The embodiments of this utility model are described in further detail below with reference to the accompanying drawings. However, these embodiments are not intended to limit this utility model. Any similar structures or variations thereof that adopt this utility model should be included in the protection scope of this utility model. The commas in this utility model all indicate the relationship between and.

[0009] like Figure 1 As shown, the present invention provides a displacement-type built-in slotted permanent magnet rotor, including a rotor core 1, on which a plurality of permanent magnet units are provided, and each permanent magnet unit is symmetrically arranged around the axis of the rotor core 1. The permanent magnet unit includes two transverse magnet groups 11 and two pairs of straight oblique magnets 12. Each transverse magnet group 11 is divided into inner and outer rows along the radial direction. Each row is provided with multiple straight magnets of different widths. A separator core is provided between each straight magnet. The two pairs of oblique magnets 12 are arranged from the inside to the outside along the radial direction of the rotor core 1. Each pair of oblique magnets 12 is symmetrically arranged relative to the d-axis and is arranged in a figure-eight shape with the narrow opening facing inward. Each oblique magnet 12 has an air permanent magnet slot 13 at both the inner and outer ends. The two transverse magnet groups 11 are respectively arranged in the narrow opening of the figure-eight shape of the oblique magnets 12, so that the two transverse magnet groups 11 and the two pairs of oblique magnet groups 12 form two U-shaped magnet groups. In each permanent magnet unit, the rotor core portion radially outer of the first U-shaped magnet group is provided with an elliptical groove 14, and the outer end face of the rotor core portion is provided with two semi-circular grooves 15. The elliptical groove 14 and the two semi-circular grooves 15 are symmetrically arranged relative to the d-axis.

[0010] The permanent magnet rotor motor of this utility model embodiment was compared with the existing built-in permanent magnet synchronous motor of the same specification. The parameters of the existing built-in permanent magnet synchronous motor are: rated power of 20KW, rated current of 19.5A, efficiency of 94.2%, rated speed of 3000r / min, maximum speed of 6500r / min, rated torque of 63.6Nm, and maximum torque of 78Nm. Compared with existing permanent magnet rotor motors of the same specifications, the motor using the permanent magnet rotor of this utility model has an efficiency increase from 94.2% to 96.2%, a cogging torque decrease from 3.75 Nm to 1.35 Nm, and a cogging torque fluctuation decrease from 5.9% to 1.92%. Therefore, the present invention improves the air gap flux density waveform and reduces motor noise and torque fluctuation.

Claims

1. A shift-type built-in slotted permanent magnet rotor, comprising a rotor core, wherein a plurality of permanent magnet units are provided on the rotor core, and the permanent magnet units are symmetrically arranged around the axis of the rotor core, characterized in that: The permanent magnet unit includes two transverse magnet groups and two pairs of straight oblique magnets. Each transverse magnet group is divided into inner and outer rows along the radial direction. Each row is provided with multiple straight magnets of different widths. A separator core is provided between each straight magnet. The two pairs of oblique magnets are arranged at intervals from the inside to the outside along the radial direction of the rotor core. Each pair of oblique magnets is symmetrically arranged relative to the d-axis and is arranged in a figure-eight shape with the narrow opening facing inward. Air permanent magnet slots are provided at both the inner and outer ends of each oblique magnet. The two transverse magnet groups are respectively arranged in the narrow opening of the figure-eight shape of the oblique magnets, so that the two transverse magnet groups and the two pairs of oblique magnets form two U-shaped magnet groups. In each permanent magnet unit, the rotor core portion radially outer of the first U-shaped magnet group is provided with an elliptical groove, and the outer end face of the rotor core portion is provided with two semi-circular grooves. The elliptical groove and the two semi-circular grooves are symmetrically arranged relative to the d-axis.

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