CN110896254A

CN110896254A - Rotor and motor with same

Info

Publication number: CN110896254A
Application number: CN201811067867.3A
Authority: CN
Inventors: 左亚军; 郭丙春; 张健强
Original assignee: Guangdong Welling Motor Manufacturing Co Ltd
Current assignee: Guangdong Welling Motor Manufacturing Co Ltd
Priority date: 2018-09-13
Filing date: 2018-09-13
Publication date: 2020-03-20

Abstract

The invention discloses a rotor and a motor with the same, wherein the rotor comprises: a mounting frame; the rotor core is arranged on the outer side of the mounting frame and comprises a plurality of sub-cores which are spaced from each other in the circumferential direction, the plurality of sub-cores and the mounting frame are mutually independent parts, a mounting groove is defined between the side wall of each two adjacent sub-cores and the outer circumferential wall of the mounting frame, and a permanent magnet is arranged in the mounting groove; and the plastic coating part is used for coating the mounting frame, the rotor core and the permanent magnet into a whole. According to the rotor of the invention, the flux leakage of the rotor is small. When the rotor is applied to the permanent magnet motor, the output torque of the permanent magnet motor can be improved, the output performance of the permanent magnet motor is enhanced, and the requirements on strength and rigidity can be well met under the action of a centrifugal force at a high rotating speed.

Description

Rotor and motor with same

Technical Field

The invention relates to the technical field of motor manufacturing, in particular to a rotor and a motor with the same.

Background

In the plastic-coated rotor structure of the existing permanent magnet motor, the following problems exist:

1. the closed structure of the inner magnetic bridge or the outer magnetic bridge of the iron core punching sheet of the rotor structure can cause larger magnetic leakage and reduce the output torque of the permanent magnet motor, thereby weakening the output performance of the permanent magnet motor;

2. the position of the permanent magnet in the rotor is generally positioned by an iron core punching structure, so that the structural design of the iron core punching is more complicated, and the service life of a high-punching die and the guarantee of high punching precision are not facilitated;

3. considering the plastic coating process of the rotor structure, a positioning process hole of a permanent magnet needs to be formed in the end part of the plastic coating material of the rotor structure, and the perforated structure easily causes stress concentration under the centrifugal force action when the permanent magnet motor runs, so that the plastic coating material is broken. Meanwhile, when the shaft is cold-pressed, the local micro deformation of the rotor core can be directly transferred to the plastic-coated material, so that the plastic-coated material is broken, and the qualification rate of the rotor structure is reduced;

4. in the rotor plastic-coating process, the flow characteristic of injection molding plastic is difficult to control, so that the problem that the radial positions of the permanent magnets are inconsistent after injection molding can be caused, the magnetic field is asymmetric, and various performance indexes of the permanent magnet motor are influenced.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. To this end, an object of the invention is to propose a rotor having a low flux leakage.

Another object of the invention is to propose an electric machine with a rotor as described above.

A rotor according to an embodiment of the first aspect of the invention comprises: a mounting frame; the rotor core is arranged on the outer side of the mounting frame and comprises a plurality of sub-cores which are circumferentially spaced from each other, the plurality of sub-cores and the mounting frame are mutually independent components, a mounting groove is defined between the side wall of each two adjacent sub-cores and the outer peripheral wall of the mounting frame, and a permanent magnet is arranged in the mounting groove; and the plastic coating part is used for coating the mounting frame, the rotor core and the permanent magnet into a whole.

According to the rotor of the embodiment of the first aspect of the present invention, by providing the plurality of sub-cores circumferentially spaced from each other and making the plurality of sub-cores and the mount frame as a plurality of members independent from each other, flux leakage of the rotor is small. When the rotor is applied to the permanent magnet motor, the output torque of the permanent magnet motor can be improved, the output performance of the permanent magnet motor is enhanced, and the requirements on strength and rigidity can be well met under the action of a centrifugal force at a high rotating speed.

According to some embodiments of the invention, the axial end bottom of the permanent magnet is exposed from the inner circumferential wall of the plastic-coated member.

According to some embodiments of the invention, an inner end of the permanent magnet is in direct contact with the outer peripheral wall of the mounting bracket.

According to some embodiments of the invention, the surface of the mounting bracket that contacts the inner end of the permanent magnet is a flat surface or an outwardly convex arc surface.

According to some embodiments of the present invention, the inner end of each sub-core has a core mounting portion, the outer peripheral wall of the mounting frame is provided with a plurality of grooves arranged at intervals in the circumferential direction, and the core mounting portions of the plurality of sub-cores are fitted in the plurality of grooves in a one-to-one correspondence.

According to some embodiments of the invention, each of the grooves is formed as a dovetail groove, and a shape of each of the core mounting parts is adapted to a shape of the dovetail groove.

According to some embodiments of the invention, at least one boss is disposed on a bottom wall of each of the grooves, and each of the core mounting portions abuts against the boss in the corresponding groove.

According to some embodiments of the invention, each of the bosses has a length L and a height H, wherein L, H respectively satisfy: l is more than or equal to 1mm and less than or equal to 5mm, and H is more than or equal to 0.1mm and less than or equal to 0.5 mm.

According to some embodiments of the invention, the mounting bracket is an integrally formed piece, or the mounting bracket is formed by axially stacking a plurality of mounting pieces.

According to some embodiments of the invention, the mount is a metal piece, a plastic piece, or a combination of metal and plastic.

An electric machine according to an embodiment of the second aspect of the invention comprises a rotor according to the above-described embodiment of the first aspect of the invention.

According to some embodiments of the invention, the electric machine is a permanent magnet machine.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a perspective view of a rotor according to an embodiment of the present invention;

FIG. 2 is a schematic view taken along the direction A in FIG. 1;

FIG. 3 is an enlarged view of the portion B circled in FIG. 2;

FIG. 4 is a cross-sectional view of a rotor according to an embodiment of the present invention;

FIG. 5 is an enlarged view of the circled portion C of FIG. 4;

FIG. 6 is a schematic view of an assembly of a rotor core and a mounting bracket according to an embodiment of the invention;

fig. 7 is an enlarged view of a portion D circled in fig. 6.

Reference numerals:

100: a rotor;

1: a mounting frame; 11: a groove; 111: a boss;

2: a sub-core; 21: mounting grooves; 22: a permanent magnet; 221: the inner end of the permanent magnet;

23: an iron core mounting part;

3: wrapping a plastic part; 4: a rotating shaft; 41: and (7) installing holes.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

A rotor 100 according to an embodiment of the present invention is described below with reference to fig. 1 to 7. The rotor 100 may be applied to a motor such as a permanent magnet motor. In the following description of the present application, the application of the rotor 100 to a permanent magnet motor is exemplified. Of course, those skilled in the art will appreciate that the rotor 100 may also be applied to other types of motors, and is not limited to permanent magnet motors.

As shown in fig. 1, a rotor 100 according to an embodiment of the first aspect of the present invention includes a mounting frame 1, a rotor core, and an overmold 3.

Specifically, referring to fig. 1 in conjunction with fig. 2 and 4, the rotor core is disposed outside the mounting frame 1. Here, it should be noted that the direction "outer" is understood to be a direction away from the central axis of the mounting bracket 1, and the opposite direction is defined as "inner", i.e. a direction towards the central axis of the mounting bracket 1.

The rotor core includes a plurality of sub-cores 2 circumferentially spaced apart from each other, and the plurality of sub-cores 2 and the mounting frame 1 are a plurality of members independent from each other. For example, in the example of fig. 4, the plurality of sub-cores 2 and the mount 1 are separately formed, and the plurality of sub-cores 2 and the mount 1 are not integrally formed. Moreover, a plurality of sub-cores 2 are arranged at intervals in the circumferential direction of the mounting frame 1, specifically, two pairs of sub-cores 2 are not in contact with each other, and the plurality of sub-cores 2 are not directly connected with each other, and the inner ends of every two adjacent sub-cores 2 are spaced from each other, and the outer ends of every two adjacent sub-cores 2 are also spaced from each other. In the description of the present invention, "a plurality" means two or more. Therefore, by arranging the rotor core comprising the plurality of sub-cores 2 which are spaced in the circumferential direction, the inner magnetic bridges and the outer magnetic bridges of the rotor core are both in an open structure, so that the problem that the traditional core punching sheet has larger magnetic leakage caused by the closed structure of the inner magnetic bridges or the outer magnetic bridges is solved, namely, the magnetic leakage of the rotor 100 according to the embodiment of the invention is small, when the rotor 100 is applied to a permanent magnet motor, the output torque of the permanent magnet motor is increased, the output performance of the permanent magnet motor is improved, and the market competitiveness of the permanent magnet motor can be effectively improved. Moreover, the opening structure of the inner magnetic bridge can meet the requirements of strength and rigidity under the action of high-rotation-speed centrifugal force, and the defect that the strength of the traditional iron core punching sheet is insufficient due to the opening structure of the inner magnetic bridge is overcome.

A mounting groove 21 is defined between the side walls of every two adjacent sub-cores 2 and the outer peripheral wall of the mounting frame 1, and a permanent magnet 22 is arranged in the mounting groove 21. The permanent magnet 22 is located through the lateral wall of two adjacent sub-cores 2 and the periphery wall of mounting bracket 1 jointly, compares with the traditional mode that only comes the location through rotor core, has simplified rotor core such as the structural shape of sub-core 2 to can simplify the structure of high-pressure punching mould, be favorable to improving the life-span of high-pressure punching mould and rotor core such as the size precision of sub-core 2.

The plastic-coated piece 3 is used for coating and molding the mounting frame 1, the rotor core and the permanent magnet 22 into a whole. Therefore, the mounting frame 1, the rotor core and the permanent magnet 22 can be conveniently and firmly connected into a whole by arranging the plastic coating piece 3.

According to the rotor 100 of the embodiment of the first aspect of the present invention, by providing the plurality of sub-cores 2 circumferentially spaced from each other and making the plurality of sub-cores 2 and the mounting frame 1 as a plurality of members independent from each other, flux leakage of the rotor 100 is small. When the rotor 100 is applied to a permanent magnet motor, the output torque of the permanent magnet motor can be improved, the output performance of the permanent magnet motor is enhanced, and the requirements on strength and rigidity can be well met under the action of a centrifugal force at a high rotating speed. In addition, a mounting groove 21 for mounting the permanent magnet 22 is defined between the side walls of the two adjacent sub-cores 2 and the peripheral wall of the mounting frame 1, so that the structural shape of the rotor sheet of the rotor core can be simplified, the simplification of a high-punching die is realized, and the service life of the high-punching die and the size precision of the rotor sheet of the rotor core are improved.

According to some embodiments of the present invention, referring to fig. 1 in combination with fig. 2 and 3, the axial end bottom of the permanent magnet 22 is exposed to the inner circumferential wall of the overmold 3. For example, the inner end 221 of the permanent magnet 22 projects inwardly of the inner circumferential wall of the plastic-coated member 3. In the direction a shown in fig. 1, the inner end 221 of the permanent magnet 22 can be seen. That is, the radial inner end of the permanent magnet 22 is partially exposed at the axial end of the whole rotor 100, and the exposed part (i.e. the inner end) of the permanent magnet 22 is used for positioning the permanent magnet 22 in a mold, such as a high-impact mold, when the rotor 100 is subjected to injection molding and plastic coating, the exposed design makes it unnecessary to provide a positioning process hole for positioning the permanent magnet 22 on the end surface of the plastic-coated part 3, so that stress concentration generated at the positioning process hole under the centrifugal force action of the plastic-coated part 3 during the operation of the permanent magnet motor is avoided, and the risk of fracture of the plastic-coated part 3 is effectively reduced.

According to some embodiments of the invention, as shown in fig. 4 and 5, the inner end 221 of the permanent magnet 22 is in direct contact with the peripheral wall of the mounting 1. For example, at this time, the portion of the radial inner end of the permanent magnet 22, which is in direct contact with the mounting frame 1, is free of injection molding material, and the injection molding material is only filled in the radial outer end of the permanent magnet 22, so that the problem that the radial positions of the permanent magnets 22 are inconsistent after the rotor 100 is coated with plastic is solved, the symmetry of the magnetic field is ensured, the efficiency of the rotor 100 is improved, and the vibration noise of the permanent magnet motor is reduced. In addition, when the pivot 4 is impressed to the cold in the mounting bracket 1, rotor core part can produce micro deformation, because above-mentioned inner of permanent magnet 22 and the periphery wall direct contact of mounting bracket 1, do not have the material of moulding plastics between the two to can effectively avoid rotor core's deformation to transmit on the package moulds 3, thereby reduced the strain that the package moulded 3, make the package mould 3 can not take place to break when the pivot 4 is pressed into to cold, promoted rotor 100's qualification rate.

Alternatively, the surface of the mounting bracket 1 contacting the inner end of the permanent magnet 22 is a flat surface or an outwardly convex arc surface. For example, in the example of fig. 4 and 5, the outer peripheral surface of the mounting bracket 1 is formed as an outwardly convex arc surface, and the inner end 221 of the permanent magnet 22 abuts against the arc surface of the mounting bracket 1. Therefore, the permanent magnet 22 can be well positioned in the mounting groove 21, the symmetry of the magnetic field is further ensured, the efficiency of the rotor 100 is further improved, and the vibration noise of the permanent magnet motor is further reduced. It will be appreciated that the surface of the mounting 1 which is in contact with the inner end of the permanent magnet 22 may also be other surfaces, such as a wavy surface or the like.

According to some embodiments of the present invention, as shown in fig. 2 to 7, the inner end of each sub-core 2 has a core mounting portion 23, the outer circumferential wall of the mounting bracket 1 is provided with a plurality of grooves 11 arranged at intervals in the circumferential direction, and the core mounting portions 23 of the plurality of sub-cores 2 are fitted in the plurality of grooves 11 in a one-to-one correspondence. From this, through setting up iron core installation department 23 and recess 11 that mutually support, sub-iron core 2 can conveniently install on mounting bracket 1, simple structure, and easily realize.

Alternatively, referring to fig. 2 to 7, each of the grooves 11 is formed as a dovetail groove, and the shape of each of the core mounting parts 23 is adapted to the shape of the dovetail groove. Thus, the plurality of sub-cores 2 and the mounting frame 1 are mounted by the dovetail groove structure, and radial deformation of the rotor 100 due to centrifugal force when the permanent magnet motor is operated is reduced.

According to some embodiments of the present invention, as shown in fig. 7, at least one boss 111 is provided on the bottom wall of each recess 11, and each core mounting portion 23 abuts against the boss 111 in the corresponding recess 11. From this, through setting up foretell boss 111, the area of contact between boss 111 and the iron core installation department 23 that corresponds is less relatively, and plastic deformation takes place more easily for boss 111, and pivot 4 is changeed interference fit with mounting bracket 1, has reduced the assembly requirement of pivot 4 with mounting bracket 1, is favorable to the assembly process of impressing of pivot 4 and mounting bracket 1, can reduce the power of impressing when the pivot 4 is impressed, has improved the feasibility of preparation technology.

Optionally, each boss 111 has a length L and a height H, wherein L, H respectively satisfies: l is more than or equal to 1mm and less than or equal to 5mm, and H is more than or equal to 0.1mm and less than or equal to 0.5 mm. Therefore, the boss 111 meets the size, the boss 111 is convenient to process, the pressing force during pressing the rotating shaft 4 can be reduced better, and the feasibility of the manufacturing process is improved.

One boss 111 is shown in fig. 7 for illustrative purposes, but it will be apparent to one of ordinary skill after reading the following disclosure that it is within the scope of the present invention to apply this disclosure to two or more bosses 111.

In the description of the present invention, it is to be understood that the terms "center", "length", "height", "up", "down", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

According to some alternative embodiments of the invention, the mounting 1 is an integrally formed part. Of course, the invention is not limited thereto, and according to other alternative embodiments of the invention, the mounting bracket 1 may also be formed by stacking a plurality of mounting pieces in the axial direction. Wherein, the mounting bracket 1 is provided with a mounting hole 41 matched with the rotating shaft 4.

Alternatively, the mounting bracket 1 is made of metal, plastic, or a combination of metal and plastic. I.e. the mounting 1 may be made of a metal material only, or of a plastic material only, or alternatively of both metal and plastic materials.

Alternatively, the rotor core may be constituted by a plurality of rotor lamination sheets stacked in the axial direction. But is not limited thereto.

The rotor 100 according to the embodiment of the invention has the advantages of small flux leakage of the rotor core, good consistency of radial distribution positions of the permanent magnets 22, good strength of the plastic-coated part 3, reduction of reject ratio of a cold pressing shaft and the like. In addition, the inner magnetic bridge opening structure of the rotor 100 can meet the strength and rigidity requirements under the action of a centrifugal force at a high rotating speed, and the defects that the strength of the inner magnetic bridge opening structure of the traditional iron core stamped steel is insufficient and the like are overcome.

A motor according to an embodiment of the second aspect of the invention comprises a rotor 100 according to the above-described embodiment of the first aspect of the invention. Among them, the motor can be applied to household appliances such as a refrigerator, a washing machine, and the like.

Optionally, the motor is a permanent magnet motor. But is not limited thereto.

According to the motor of the embodiment of the second aspect of the present invention, by using the rotor 100 described above, the overall performance of the motor, for example, a permanent magnet motor, can be improved.

Other constructions and operations of electric machines, such as permanent magnet machines, according to embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A rotor, comprising:

a mounting frame;

the rotor core is arranged on the outer side of the mounting frame and comprises a plurality of sub-cores which are circumferentially spaced from each other, the plurality of sub-cores and the mounting frame are mutually independent components, a mounting groove is defined between the side wall of each two adjacent sub-cores and the outer peripheral wall of the mounting frame, and a permanent magnet is arranged in the mounting groove;

and the plastic coating part is used for coating the mounting frame, the rotor core and the permanent magnet into a whole.

2. The rotor of claim 1, wherein axial end bottoms of the permanent magnets are exposed from an inner circumferential wall of the overmold.

3. A rotor according to claim 1 or 2, wherein the inner ends of the permanent magnets are in direct contact with the outer peripheral wall of the mounting frame.

4. The rotor of claim 3, wherein the surface of the mounting bracket contacting the inner end of the permanent magnet is a flat surface or an outwardly convex arc surface.

5. The rotor of claim 1, wherein each of the inner ends of the sub-cores has a core mounting portion, a plurality of grooves are formed in the outer peripheral wall of the mounting frame at intervals in the circumferential direction, and the core mounting portions of the plurality of sub-cores are fitted in the plurality of grooves in a one-to-one correspondence manner.

6. The rotor of claim 5, wherein each of the grooves is formed as a dovetail groove, and a shape of each of the core mounting portions is adapted to a shape of the dovetail groove.

7. The rotor of claim 5, wherein at least one boss is arranged on the bottom wall of each groove, and each iron core mounting part is abutted against the boss in the corresponding groove.

8. The rotor as set forth in claim 7 wherein each of said lands has a length L and a height H, wherein said L, H respectively satisfy: l is more than or equal to 1mm and less than or equal to 5mm, and H is more than or equal to 0.1mm and less than or equal to 0.5 mm.

9. The rotor as claimed in claim 1, wherein the mounting bracket is an integrally formed member or is formed by stacking a plurality of mounting pieces in an axial direction.

10. The rotor of claim 1, wherein the mounting bracket is a metal piece, a plastic piece, or a combination of metal and plastic.

11. An electrical machine comprising a rotor according to any of claims 1-10.

12. The electric machine of claim 11, wherein the electric machine is a permanent magnet machine.