A rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure and motor

Abstract

The invention discloses a rare earth permanent magnet and ferrite permanent magnet hybrid split-lobed rotor punching structure and a motor, which relates to the technical field of permanent magnet motors; comprising: a tangential punching, with disconnected magnetic isolation bridges extending outwards on both sides of the end; a rare earth permanent magnet steel groove between adjacent tangential punchings, in which a rare earth permanent magnet steel is placed; a straight punching, which is connected to the tangential punching and the two are an integrated structure, and a ferrite permanent magnet steel groove is opened on the straight punching, in which a ferrite permanent magnet steel is placed; a non-disconnected magnetic isolation bridge is formed between the bottom of the rare earth permanent magnet steel groove and the top of the adjacent ferrite permanent magnet steel groove, and between the side walls of the adjacent ferrite permanent magnet steel groove. The amount of rare earth permanent magnet material is reduced, the amount of ferrite permanent magnet material is increased, and the cost of permanent magnet motor magnet steel is greatly reduced; by setting the non-disconnected magnetic isolation bridge, the magnetic isolation aluminum ring set on the split-lobed rotor punching can be cancelled.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnet motors, and in particular to a rare earth permanent magnet and ferrite permanent magnet hybrid split-lobed rotor punching structure and a motor. Background Art

[0002] Compared with the straight rotor laminations, the tangential rotor laminations significantly reduce the use of magnetic steel due to their magnetic concentration effect, so they are widely used in electric vehicles, servo systems, low-speed direct drives and other fields. However, the current tangential rotor lamination structure, especially the split-petal design, mainly relies on magnetic isolation rings to achieve magnetic isolation. The magnetic isolation rings are mostly made of aluminum alloy or other non-magnetic materials, which leads to complex rotor structure, reduced mechanical strength and reduced reliability.

[0003] In addition, as the price of rare earth permanent magnet materials continues to rise, the manufacturing cost of permanent magnet motors with tangential rotor lamination structures is also getting higher and higher. In contrast, although the residual magnetic density of ferrite permanent magnet materials is relatively low, they do not contain rare earth elements and have obvious cost advantages. The price is only one-tenth or less of rare earth permanent magnet materials.

[0004] In summary, the current permanent magnet motor with a tangential split rotor lamination structure faces problems such as complex rotor structure, insufficient strength, poor reliability and high manufacturing cost. Summary of the invention

[0005] The purpose of the present invention is to provide a rare earth permanent magnet and ferrite permanent magnet hybrid split rotor stamping structure and motor, which has the advantages of simple rotor structure, high strength, good reliability, etc., and also greatly reduces the cost of permanent magnet motor magnetic steel.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is: a rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure, comprising:

[0007] The tangential punching sheet has two ends with disconnected magnetic isolation bridges extending outwards; between adjacent tangential punching sheets are rare earth permanent magnetic steel grooves, in which rare earth permanent magnetic steel is placed;

[0008] The straight punching sheet is connected to the tangential punching sheet and the two are an integrated structure. A ferrite permanent magnet steel groove is opened on the straight punching sheet, and the ferrite permanent magnet steel is placed in the groove;

[0009] A non-disconnecting magnetic isolation bridge is formed between the bottom of the rare earth permanent magnet steel slot and the top of the adjacent ferrite permanent magnet steel slot and between the side walls of the adjacent ferrite permanent magnet steel slot.

[0010] In one embodiment, the circumferential angle occupied by each rotor punching structure is 360° / N, and N rotor punching structures are spliced ​​into a full circle; multiple rotor punching structures are stacked in the axial direction to a required height.

[0011] In one embodiment, the rare earth permanent magnet steel slot is a tangential structure, and the ferrite permanent magnet steel slot is a straight structure.

[0012] In one embodiment, the rare earth permanent magnet steel slot and the ferrite permanent magnet steel slot are in a U-shaped structure.

[0013] In one embodiment, a full circle formed by splicing N rotor punchings has a total of N rare earth permanent magnet steel slots and N ferrite permanent magnet steel slots.

[0014] In one of the embodiments, the non-disconnecting magnetic isolation bridge is a T-shaped structure.

[0015] In one of the embodiments, the width of the non-disconnecting magnetic isolation bridge is 1.5-2.5 mm.

[0016] In one of the embodiments, a fixing screw hole is provided on the tangential punching sheet, and a fixing screw is inserted into the hole, so that the axial multiple rotor punching sheet structures are fixed together by the fixing screw.

[0017] In one embodiment, a stainless steel keyway is provided on the straight punching sheet, a stainless steel key is inserted into the slot, and the rotor punching sheet and the rotor bracket are fixed together by the stainless steel key.

[0018] A motor has a rotor, wherein the rotor is formed by stacking the above-mentioned rotor punching sheet structure.

[0019] The present invention adopts the above technical solution, and can achieve the following technical effects:

[0020] Compared with the prior art, the rare earth permanent magnet and ferrite permanent magnet hybrid split rotor punching structure and motor of the present invention reduce the amount of rare earth permanent magnet material used and increase the amount of ferrite permanent magnet material used by setting rare earth permanent magnet steel slots and ferrite permanent magnet steel slots, thereby greatly reducing the magnet steel cost of the permanent magnet motor.

[0021] Compared with the prior art, the rare earth permanent magnet and ferrite permanent magnet hybrid split-type rotor punching structure and motor of the present invention can eliminate the magnetic isolation aluminum ring set in the split-type rotor punching by setting a non-disconnecting magnetic isolation bridge, and directly fix the rotor punching to the rotor bracket through a stainless steel key, thereby having the advantages of simple rotor structure, high strength, good reliability, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a schematic diagram of the structure of the rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination;

[0024] Figure 2 It is a schematic diagram of the structure of the existing tangential split rotor lamination;

[0025] Figure 3 Taking a 90kW motor as an example, the following is a comparison diagram of the no-load back electromotive force between the existing punching sheet and the punching sheet of the present invention.

[0026] Explanation of the serial numbers in the figure: 1. Disconnection type magnetic isolation bridge; 2. Non-disconnection type magnetic isolation bridge; 3. Rare earth permanent magnet steel slot; 4. Ferrite permanent magnet steel slot; 5. Fastening screw hole; 6. Stainless steel keyway; 7. Magnetic isolation aluminum ring. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0029] In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0030] In the description of the present application, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] See also Figure 1 This embodiment provides a rare earth permanent magnet and ferrite permanent magnet hybrid split-lobed rotor punching structure, including:

[0033] The tangential punching sheet has two ends with disconnected magnetic isolation bridges extending outward; between adjacent tangential punching sheets are rare earth permanent magnet steel slots, which are tangential structures and have rare earth permanent magnet steel placed inside; the tangential punching sheet is provided with a fixing screw hole, into which a fixing screw is inserted, and the axial multiple rotor punching sheet structures are fixed together by the fixing screw;

[0034] The straight punching sheet is connected to the tangential punching sheet and the two are an integrated structure. A ferrite permanent magnet steel slot is opened on the straight punching sheet. The slot is a straight structure and a ferrite permanent magnet steel is placed inside. A stainless steel key slot is provided on the straight punching sheet. A stainless steel key is inserted into the slot. The rotor punching sheet and the rotor bracket are fixed together by the stainless steel key.

[0035] In this embodiment, the rare earth permanent magnet steel slots 3 and the ferrite permanent magnet steel slots 4 are preferably U-shaped structures, and the rotor punchings can be inserted with both rare earth permanent magnet steels and ferrite magnets, that is, the magnets made of inexpensive ferrite materials with low residual magnetic density can replace part of the rare earth permanent magnet material magnets, thereby reducing the cost of the magnets while meeting the motor performance.

[0036] A non-disconnecting magnetic isolation bridge is formed between the bottom of the rare earth permanent magnet steel slot and the top of the adjacent ferrite permanent magnet steel slot, and between the side walls of the adjacent ferrite permanent magnet steel slot. The non-disconnecting magnetic isolation bridge is designed to be very narrow, that is, the bridge width is preferably 1.5-2.5mm. The magnetic flux density at this location is easy to reach saturation, so the magnetic resistance is large, which can play a role in magnetic isolation. Therefore, this application does not require a magnetic isolation aluminum ring.

[0037] As a preferred implementation scheme provided in this embodiment, the circumferential angle occupied by each rotor punching structure is 360° / N, and N rotor punchings are spliced ​​into a whole circle, which has a total of N rare earth permanent magnet steel slots and N ferrite permanent magnet steel slots; multiple rotor punching structures are stacked in the axial direction to the required height.

[0038] like Figure 2 As shown, the existing tangential split rotor punching includes a disconnected magnetic isolation bridge, a rare earth permanent magnet steel slot, a magnetic isolation aluminum ring, a fixing screw hole, and a stainless steel keyway. A rare earth permanent magnet steel is placed in the rare earth permanent magnet steel slot 8, a magnetic isolation aluminum ring is arranged under the magnet steel, and a stainless steel key is inserted into the stainless steel keyway 11, and the magnetic isolation aluminum ring, the rotor punching and the rotor bracket are fixedly connected by the stainless steel key.

[0039] Example 2

[0040] A motor has a rotor, wherein the rotor is formed by stacking the rotor punching structure described in Example 1.

[0041] This embodiment designs a permanent magnet motor with a center height of 400mm, 90Kw, 380V, and 230rpm. As shown in Table 1, the total price of the existing tangential split rotor punching structure magnet steel is 7370 yuan, and the total price of the punching magnet steel of the present invention is 6381 yuan, and the magnet steel cost is reduced by 13.4%. Figure 3 As shown, the line no-load back EMF of the existing punching sheet and the punching sheet of the present invention, the back EMF curves of the two are close to overlap, the line no-load back EMF effective value of the existing punching sheet is 339V, and the line no-load back EMF of the punching sheet of the present invention is 335V. It shows that the performance of the two punching sheets is not much different, but the punching sheet of the present invention has a better cost.

[0042] Table 1 The cost of magnetic steel of the existing tangential split rotor lamination structure and the rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure of the present invention

[0043]

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure, characterized in that: include: Tangential punching sheet, with disconnected magnetic isolation bridges extending outwards on both sides of its end; Between adjacent tangential punching sheets are rare earth permanent magnet steel grooves, in which rare earth permanent magnet steel is placed; A straight punching sheet is connected to a tangential punching sheet and the two are an integrated structure. A ferrite permanent magnet steel groove is opened on the straight punching sheet, and a ferrite permanent magnet steel is placed in the ferrite permanent magnet steel groove; A non-disconnecting magnetic isolation bridge is formed between the bottom of the rare earth permanent magnet steel slot and the top of the adjacent ferrite permanent magnet steel slot, and between the side walls of the adjacent ferrite permanent magnet steel slots; The rare earth permanent magnet steel slot is a tangential structure, and the ferrite permanent magnet steel slot is a straight structure.

2. According to claim 1, a rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure is characterized in that: The circumferential angle occupied by each rotor punching structure is 360° / N, and N rotor punchings are spliced ​​into a full circle; multiple rotor punching structures are stacked in the axial direction to the required height.

3. The rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure according to claim 1, characterized in that: The rare earth permanent magnet steel slot and the ferrite permanent magnet steel slot are in a U-shaped structure.

4. The rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure according to claim 2, characterized in that: The whole circle formed by splicing N rotor punchings has a total of N rare earth permanent magnet steel slots and N ferrite permanent magnet steel slots.

5. The rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure according to claim 1, characterized in that: The non-disconnecting magnetic isolation bridge is a T-shaped structure.

6. A rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure according to claim 1 or 5, characterized in that: The width of the non-disconnecting magnetic isolation bridge is 1.5-2.5 mm.

7. The rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure according to claim 1, characterized in that: The tangential punching sheet is provided with a fixing screw hole, into which a fixing screw is inserted, and the axial multiple rotor punching sheet structures are fixed together by the fixing screw.

8. The rare earth permanent magnet and ferrite permanent magnet hybrid split rotor lamination structure according to claim 1, characterized in that: A stainless steel keyway is provided on the straight punching sheet, a stainless steel key is inserted into the stainless steel keyway, and the rotor punching sheet and the rotor bracket are fixed together by the stainless steel key.

9. An electric motor having a rotor, characterized in that: The rotor is formed by laminating the rare earth permanent magnet and ferrite permanent magnet hybrid split rotor punching structure as described in any one of claims 1 to 8.

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