Rotor, permanent magnet synchronous motor and die

Abstract

The utility model provides a rotor used for a permanent magnet synchronous motor. The rotor comprises a rotor frame and permanent magnets. The rotor frame is constructed to be a hollow cylinder, the rotor frame is provided with a plurality of interval grooves in the circumferential direction, and the rotor frame is divided into a plurality of rotor frame sub-parts by the interval grooves; the permanent magnets are arranged in the interval grooves; wherein the rotor frame is integrally cast through a pouring gate, the rotor frame sub-part is provided with a pouring gate stub bar corresponding to the pouring gate, the pouring gate stub bar is located on the end face of the rotor frame, and the pouring gate stub bar is closer to the outer circumference of the rotor frame than the inner circumference of the rotor frame. In addition, the utility model also relates to a permanent magnet synchronous motor comprising the rotor and a mold for casting the rotor.

Description

Technical Field

[0001] The utility model relates to a rotor for a permanent magnet synchronous motor, a permanent magnet synchronous motor comprising the rotor and a mold for casting the rotor. Background Art

[0002] The rotor currently used for permanent magnet synchronous motors is composed of a magnetizer and a permanent magnet, wherein the magnetizer is formed by stacking stamped silicon steel sheets, and the permanent magnet is embedded in the magnetizer. The silicon steel sheets constituting the magnetizer can be, for example, non-oriented silicon steel sheets or oriented silicon steel sheets. The difference in magnetic permeability or magnetic permeability in each direction of the non-oriented silicon steel sheet is very small, that is, there is no directional difference, while the magnetic permeability or magnetic permeability of the oriented silicon steel sheet in different directions is different, that is, it has excellent magnetic permeability in a specific direction, and poor magnetic permeability in other directions.

[0003] When the rotor magnetizer is made of non-oriented silicon steel sheets, the magnetization depth of the magnetizer is not deep enough. When oriented silicon steel sheets are used, the magnetization of the magnetizer will be uneven due to the specific orientation of the silicon steel sheets. In addition, the magnetizer itself is non-magnetic, which results in a waste of rotor space for the magnetizer, making the rotor space not fully utilized and unable to maximize the magnetic flux of the rotor. Utility Model Content

[0004] The utility model provides a rotor for a permanent magnet synchronous motor, which can effectively increase the magnetization depth of the rotor, thereby improving the performance of the rotor and the motor with the rotor.

[0005] The utility model proposes a rotor for a permanent magnet synchronous motor, the rotor comprising a rotor frame and permanent magnets; the rotor frame is constructed as a hollow cylinder, the rotor frame has a plurality of spacing grooves along the circumferential direction, the rotor frame is divided into a plurality of rotor frame sub-parts by the spacing grooves; the permanent magnets are arranged in the spacing grooves; wherein the rotor frame is integrally cast through a gate, the rotor frame sub-part has a gate head corresponding to the gate, the gate head is located on the end face of the rotor frame, and the gate head is closer to the outer circumference of the rotor frame than the inner circumference of the rotor frame.

[0006] In an embodiment of the present invention, each rotor frame sub-section has a gate sprue, and the number of the gate sprues is equal to the number of poles of the rotor.

[0007] In an embodiment of the present invention, the gate nozzle has a cross section that is long and narrow in a circumferential direction, and the gate nozzle extends to the outer circumference of the rotor frame.

[0008] In an embodiment of the present invention, the circumferential length of the cross section that is elongated in the circumferential direction is more than twice the radial length.

[0009] In an embodiment of the present invention, the cross-section of the gate nozzle forms a fan ring shape, the outer arc of the fan ring has the same curvature as the outer circumference of the rotor frame, and the gate nozzle is located on the outer circumference of the rotor frame.

[0010] In an embodiment of the present invention, the gate tip has a circular cross section.

[0011] In an embodiment of the present invention, the gate tip protrudes from the end surface of the rotor frame.

[0012] In an embodiment of the present invention, the rotor frame is made of plastic ferrite.

[0013] In an embodiment of the utility model, the spacing groove is used to accommodate a magnetic field application device during the orientation and magnetization process, so that the rotor frame obtains permanent magnetism; wherein the rotor frame sub-portion has a magnetic field direction extending in the radial direction of the rotor frame, and the rotor frame sub-portions on both sides of the spacing groove have opposite magnetic field directions respectively; wherein the magnetic field direction of the permanent magnet extends in the circumferential direction of the rotor frame; and wherein the magnetic field of the permanent magnet in the spacing groove together with the magnetic field of the rotor frame on both sides of the spacing groove forms a continuous magnetic circuit with the shortest path.

[0014] In an embodiment of the present invention, the spacing groove penetrates the rotor frame along the longitudinal direction of the rotor frame, and the cross section of the spacing groove is configured as a trapezoid, with the lower base of the trapezoidal cross section close to the inner circumference of the rotor frame.

[0015] The utility model also provides a permanent magnet synchronous motor, which comprises the rotor according to the embodiment of the utility model.

[0016] The utility model also provides a mold, which is used to cast the rotor frame of the rotor according to the above-mentioned embodiment of the utility model, the mold is hollow, the outer contour of the mold is constructed as a hollow cylinder, the mold has a plurality of spacing grooves along the circumferential direction, and the mold is divided into a plurality of mold sub-parts by the spacing grooves; wherein the mold sub-parts have a gate, the gate is located on the end face of the mold, and the gate is closer to the outer circumference of the mold than the inner circumference of the mold, wherein the position of the gate corresponds to the position of the gate head of the rotor frame.

[0017] In the prior art, the magnetizer of the rotor is usually formed by stamping and stacking silicon steel sheets. However, the magnetization depth of non-oriented silicon steel sheets is not deep enough overall; the magnetization direction of oriented silicon steel sheets is fixed, so the magnetization depth will be uneven after magnetization. In addition, if silicon steel sheets are manufactured and assembled according to the desired orientation, such as the orientation in the embodiment of the utility model, the manufacturing and assembly process must be complicated and costly.

[0018] Compared with the prior art, the rotor according to the utility model adopts a rotor frame to replace the magnetizer. The rotor frame itself is magnetic and can provide additional magnetic flux. The rotor can therefore provide more magnetic flux, and a synchronous motor with such a rotor can obtain greater power and stronger performance. The rotor according to the utility model is cast in one piece through the gate of the mold, and the gate is closer to the outer circumference of the rotor frame than the inner circumference of the rotor frame. The closer the gate is to the outer circumference, the stronger the magnetic field to which the casting material is subjected, and the more orderly the orientation of the magnetic particles in the casting material is arranged, and the density of the magnetic particles becomes larger, and the magnetic flux becomes larger. In addition, the one-piece rotor frame is made of magnetic material, and preferably a magnetic material with low magnetic resistance and good magnetic conductivity can be selected, and the processing technology of the one-piece rotor frame is simple, material-saving, low-cost, and very suitable for industrial mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the embodiment of the utility model, the following is a brief introduction to the drawings required for the description of the embodiment. Obviously, the drawings described below are only some exemplary embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 An exploded perspective view of a rotor for a permanent magnet synchronous motor according to an embodiment of the utility model is shown.

[0021] Figure 2 shows a cross-sectional view of a rotor frame according to an embodiment of the utility model,

[0022] Figure 3 A schematic diagram showing the magnetic field direction of the rotor frame according to an embodiment of the utility model is shown.

[0023] Figure 4 A schematic diagram showing the magnetic field trend of the rotor according to an embodiment of the utility model, and

[0024] Figure 5 A cross-sectional view of a rotor frame according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the technical solution of the utility model clearer, the technical solution of the embodiment of the utility model will be clearly and completely described in conjunction with the drawings of the specific embodiments of the utility model. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the described embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] Compared with the embodiments shown in the drawings, feasible implementations within the scope of protection of the present invention may have fewer components, other components not shown in the drawings, different components, differently arranged components, or differently connected components, etc. In addition, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0027] Figure 1 An exploded view of a rotor 100 for a permanent magnet synchronous motor according to an embodiment of the utility model is schematically shown. The rotor 100 includes a rotor frame 110 and a permanent magnet 120. The rotor frame 110 is configured as a hollow cylinder. In the utility model, the rotor frame 110 is configured as a hollow cylinder, which is particularly understood as the outer contour of the rotor frame 110 being a hollow cylinder. In the embodiment according to the utility model, the outer circumferential surface of the rotor frame 110 can be, for example, a closed surface, so as to obtain better structural strength. A plurality of spacing grooves 130 are arranged inside the rotor frame 110 along the circumferential direction, and the rotor frame 110 is divided into a plurality of rotor frame sub-sections 111 by the spacing grooves 130. In the embodiment according to the utility model, the spacing grooves 130 penetrate the rotor frame 110 in the axial direction. A plurality of permanent magnets 120 are respectively arranged in the spacing grooves 130, and are particularly inserted into the spacing grooves 130.

[0028] The rotor frame 110 is cast in one piece. The mold for casting the rotor frame 110 has a gate. After the cast rotor frame 110 is taken out of the mold, a gate head is formed at a position corresponding to the gate. Figure 1 The rotor frame 110 has a gate head 230 corresponding to the gate, and the gate head 230 is located at the end surface of the rotor frame 110. In the present invention, the gate head 230 is closer to the outer circumference of the rotor frame 130 than the inner circumference of the rotor frame 130. In other words, during the casting of the rotor frame 110, the gate on the mold is closer to the outer circumference of the rotor frame 110 than the inner circumference of the rotor frame 130, and preferably close to the outer circumference of the rotor frame 110.

[0029] In the prior art, the rotor of a permanent magnet synchronous motor is composed of a magnetizer and a permanent magnet. The permanent magnet can be attached to the surface of the magnetizer to form a surface-mounted rotor, or the permanent magnet can be inserted into the magnetizer to form an embedded rotor. This form of magnetizer is formed by stamping and stacking silicon steel sheets, and therefore cannot be manufactured by an integrated molding process. Compared with the prior art, an integrated rotor frame is used in the rotor according to the utility model to replace the magnetizer. In the utility model, the rotor frame can be injection molded of plastic ferrite, for example, so that it can be prepared very conveniently by an integrated molding process. The integrated molding process of the rotor frame is simple in process, high in efficiency, high in precision, and low in cost compared to the process of stamping and stacking silicon steel sheets. In addition, the rotor frame composed of plastic ferrite itself can provide a magnetic field and a magnetic force, and its magnetic permeability is much higher than that of the silicon steel sheet magnetizer.

[0030] In order to make the rotor frame 110 itself obtain stronger magnetism, the rotor frame 110 needs to be oriented during the casting or injection molding process so that each sub-part of the rotor frame 110 forms anisotropic magnets, and the rotor frame 110 needs to be magnetized so that each sub-part of the rotor frame 110 obtains magnetism in the orientation direction. During orientation, a magnetic field applying device, i.e., an orientation device, is arranged on the outer circumference of the rotor frame 110 and has alternating, paired magnetic poles. Under the action of the external magnetic field applied by the magnetic field applying device, the magnetic poles of the magnetic particles in the plastic ferrite in the rotor frame 110 are aligned and oriented. The orientation direction and magnetic field direction of the rotor frame 110 will be described in more detail later. The plastic ferrite enters from the gate of the mold. The closer the gate is to the outer circumference of the rotor frame 110, the stronger the magnetic field to which the plastic ferrite is subjected, and the more orderly the orientation arrangement of the magnetic particles. The magnetic particles in the plastic ferrite are closely attached to the outer circumference of the rotor frame 110 under the action of the magnetic field, which makes the magnetic particles arranged from the outside to the inside, and the density of the magnetic particles increases, and the magnetic flux increases. Compared with the arrangement where the gate is closer to the inner circumference of the rotor frame 110, the orientation of each sub-part of the rotor frame 110 according to the utility model is more orderly, has a larger magnetic flux, and has better rotor performance.

[0031] In the present invention, the one-piece molding process should be understood as the molding process of the entire part in one mold at one time. Compared with the traditional step-by-step manufacturing process, one-piece molding greatly reduces the cost of part production, faster production speed, and can produce various parts, products, tools, etc. in a very short time. The process flow of one-piece molding is relatively simple, and the required contours, holes, surface treatment, etc. can be completed in one mold, which can greatly reduce production time and cost, and at the same time improve the production accuracy and repeatability of parts. In the traditional processing method, it is necessary to prepare the mold and template first, and then the parts are processed step by step. The one-piece molding process does not require additional preparation of templates, etc., and it can be truly completed in one step, and the processing efficiency and speed are greatly improved. In addition, the mold designed by the one-piece molding process is usually produced in one time, so the speed is very fast, and large-scale production can be completed quickly, which can meet market demand more quickly. The one-piece molding process can not only meet the needs of the traditional manufacturing field, but also can be applied to some high-tech fields, such as generators, car wash manufacturing, medical equipment, etc. In these fields, the one-piece molding process can create more precise and higher-quality parts and products.

[0032] In an embodiment of the utility model, the plastic ferrite used for injection molding of the rotor frame has low magnetic resistance, good magnetic conductivity, deep magnetization depth, and is suitable for one-piece molding and industrial production. In an embodiment according to the utility model, the plastic ferrite can be, for example, a mixture of nylon and ferrite. The rotor frame made of plastic ferrite accommodates permanent magnets, and the rotor space is therefore fully utilized, so that the rotor can provide a larger magnetic flux without changing its volume. Plastic ferrite has a smaller density than silicon steel material, which results in a reduced weight of the rotor made of plastic ferrite, thereby improving the power density and energy efficiency of the motor. In addition, plastic ferrite has smaller hysteresis loss than silicon steel material, and has a higher resistivity, so the rotor made of plastic ferrite can have lower eddy current loss than the rotor made of silicon steel material.

[0033] In the embodiment according to the present invention, after casting and demoulding, due to the existence of the gate, a gate head 230 must be formed on the rotor frame 110. The gate head 230 may, for example, protrude from the end surface of the rotor frame 110. Alternatively, the gate head 230 may also be removed, for example, sheared off, but a mark may still be left on the end surface of the rotor frame 110.

[0034] In an embodiment of the present invention, each rotor frame sub-section 111 of the rotor frame 110 may have a gate sprue 230 , for example. The number of the gate sprues 230 is equal to the number of poles of the rotor. Figure 1As shown, magnetic poles are formed in each rotor frame sub-section 111, and the rotor has 5 pairs of poles (10 poles). The rotor frame has 10 gate sprues 230. Accordingly, the mold for casting the rotor frame has 10 gates. The material for casting, such as plastic ferrite, can be filled into the cavity in the shortest way through the corresponding gate path to form the corresponding rotor frame sub-section 111. The rotor frame sub-section 111 and its gate respectively correspond to a magnetic pole of the magnetic field applying device, so the material entering from the corresponding gate can be more strongly affected by the corresponding magnetic pole, so that it can have a more uniform orientation and stronger magnetism.

[0035] Figure 2 A cross-sectional view of a rotor frame 110 according to an embodiment of the utility model is shown. In this embodiment, the gate sprue 230, for example, has a cross-section that is long and narrow in the circumferential direction, and the gate sprue 230 is close to the outer circumference of the rotor frame 110 or extends to the outer circumference of the rotor frame 110. As mentioned above, during the injection molding process, the closer the gate is to the outer circumference of the rotor frame 110, the stronger the magnetic field of the magnetic field applying device to the plastic ferrite. In order to make the gate closer to the outer circumference of the rotor frame 110 as a whole, the gate is designed as a long and narrow opening in the circumferential direction, and the gate sprue 230 forms a long and narrow cross-section accordingly. In an embodiment according to the utility model, the circumferential length of the cross-section that is long and narrow in the circumferential direction can be, for example, more than twice the radial length, and the maximum length of the cross-section that is long and narrow in the circumferential direction can be, for example, more than twice the maximum length in the radial direction, and preferably more than more times. In a more preferred embodiment, the cross-section of the gate that is long and narrow in the circumferential direction can be, for example, formed into a fan ring, and the outer arc of the fan ring has the same curvature as the outer circumference of the rotor frame 110. The gate nozzle 230 can therefore be located on the outer circumference of the rotor frame 110, that is, partially coincide with the contour of the outer circumference. In this case, the gate of the mold for casting the rotor frame 110 can be arranged on the outer circumference of the rotor frame 110, that is, as close to the outer circumference as possible.

[0036] In the embodiment according to the present invention, the spacing groove 130 penetrates the rotor frame 110 along the longitudinal direction of the rotor frame 110. The cross section of the spacing groove 130 can be configured as a trapezoid, for example, the lower base of the trapezoidal cross section is close to the inner circumference of the rotor frame 110, and the upper base of the trapezoidal cross section is close to the outer circumference of the rotor frame 110. Trapezoidal permanent magnets 120 are arranged in the trapezoidal spacing groove 130, and this arrangement can make the magnetic field pass through the rotor frame 110 more, thereby reducing magnetic leakage.

[0037] Figure 3The schematic diagram of the magnetic field trend of the rotor frame 110 according to the embodiment of the utility model is shown. During the casting process of the rotor frame 110, a magnetic field applying device, namely an orientation device 310, is arranged around the rotor frame 110. The orientation device 310 has pairs of magnetic poles that are alternately changed. Figure 3 The embodiment of the present invention shows 5 pairs of poles (10 poles). According to the usual regulations, outside the magnet, the magnetic field lines start from the N pole and reach the S pole; inside the magnet, the magnetic field lines start from the S pole and reach the N pole. All embodiments of the present invention describe the magnetic field direction according to the above regulations. Figure 3 As can be seen in the figure, the magnetic poles of the orientation device 310 are arranged corresponding to each rotor frame sub-section. The magnetic field applied by the orientation device 310 extends in the radial direction in the rotor frame sub-sections on both sides of one of the spacing slots 130 and has opposite directions. For example, the magnetic field direction in the rotor frame sub-section 311 is oriented outward along the radial direction of the rotor frame 110, and the magnetic field direction in the rotor frame sub-section 312 is oriented inward along the radial direction of the rotor frame 110. Under the action of the external magnetic field, the magnetic poles of the magnetic particles in the plastic magnetic material, such as the plastic magnetic ferrite, will change from the original disorderly arrangement to a neat arrangement consistent with the direction of the external magnetic field, and each rotor frame sub-section will therefore behave as an anisotropic ferromagnetic material, and its orientation direction is consistent with the direction of the external magnetic field. In the subsequent magnetization process, the direction of the magnetic field applied by the magnetization device is consistent with the orientation direction. Under the action of the magnetization device, the rotor frame 110 and each rotor frame sub-section obtain permanent magnetism. After the orientation process, each rotor frame sub-section will have better magnetic conductivity, that is, higher magnetic permeability and lower magnetic resistance in a specific direction.

[0038] In another embodiment of the present disclosure, in addition to arranging a magnetic field applying device around the rotor frame 110, a magnetic field applying device may be arranged in the spacing groove 130, for example. The magnetic field applied by the magnetic field applying device in the spacing groove 130 may be the same as the magnetic field of the permanent magnet 120, for example. This will be described in detail later. By additionally arranging a magnetic field applying device in the spacing groove 130, a stronger magnetic field can be applied to the rotor frame and the ferromagnetic particles therein, so that these ferromagnetic particles can be aligned according to the desired magnetic field direction and have better magnetic conductivity, that is, higher magnetic permeability and lower magnetic resistance along the magnetic field direction.

[0039] Figure 4 FIG. 1 is a schematic diagram showing the magnetic field trend of the rotor according to an embodiment of the present utility model. Figure 4In the embodiment shown in , the rotor frame 110 of the rotor 100 has been oriented and magnetized and has obtained permanent magnetism. The permanent magnet 120 is inserted into the spacing slot 130. The magnetic field direction of the permanent magnet 120 is designed so that the rotor frame sub-parts on both sides of one of the spacing slots 130 and the permanent magnet 120 form a continuous magnetic circuit with the shortest path. In an embodiment according to the utility model, the material of the permanent magnet 120 may include, for example, ferrite, neodymium iron boron, samarium iron nitrogen and samarium cobalt. The permanent magnet composed of samarium cobalt, neodymium iron boron or samarium iron nitrogen has strong remanence, high power density, high coercive force, and good anti-demagnetization ability, so it is very suitable for high-power and high-torque motors. In an embodiment according to the utility model, the permanent magnet 120 may be sintered or bonded, for example, it may be sintered ferrite. In the case where the permanent magnet is made of sintered ferrite, the entire rotor does not use rare earth materials at all, so the cost of the rotor is further reduced.

[0040] exist Figure 4 In the illustrated embodiment, the rotor 100 has alternating N poles and S poles and forms a rotor with a plurality of pole pairs. Figure 4 The magnetic poles of the rotor 100 or the rotor frame 111 itself shown in FIG. Figure 3 What is shown is the magnetic pole of the external magnetic field applying device 310. Under the action of the S pole of the external magnetic field applying device 310, the corresponding rotor frame sub-part forms an N pole; under the action of the N pole of the external magnetic field applying device 310, the corresponding rotor frame sub-part forms an S pole. Figure 4 and Figure 3 The direction of the magnetic field is the same. Figure 4 As shown, the rotor frame subsection corresponding to the S pole of the rotor 100 has a magnetic field direction extending radially inward, and the rotor frame subsection corresponding to the N pole of the rotor 100 has a magnetic field direction extending radially outward. Between the adjacent S poles and N poles of the rotor 100, the magnetic field starts from the S pole, transitions through the permanent magnet in the shortest path and reaches the N pole, and the magnetic field in the permanent magnet extends in the circumferential direction. For example, the permanent magnet 421 is arranged in the spacing slot 431, the permanent magnet 422 is arranged in the spacing slot 432, and the permanent magnet 423 is arranged in the spacing slot 433. The magnetic field direction of the permanent magnet 423 extends in the circumferential direction of the rotor frame 110 and is opposite to the magnetic field direction of the adjacent permanent magnet 422. On both sides of the permanent magnet 422 or the spacing slot 432 are the rotor frame subsections 411 and 412, and on both sides of the permanent magnet 423 or the spacing slot 433 are the rotor frame subsections 412 and 413. From Figure 4As can be seen in FIG, the magnetic field starts from the S pole corresponding to the rotor frame subsection 412 and extends inwardly in the radial direction of the rotor frame 110 in the rotor frame subsection 412. Then the magnetic field is separated, one part of the magnetic field bends through the permanent magnet 422, and the other part of the magnetic field bends through the permanent magnet 423. The magnetic field extends counterclockwise in the circumferential direction of the rotor frame 110 in the permanent magnet 422, and the magnetic field bends after passing through the permanent magnet 422 and extends outwardly in the radial direction of the rotor frame 110 through the rotor frame subsection 411 to reach the N pole corresponding to the rotor frame subsection 411. The magnetic field extends clockwise in the circumferential direction of the rotor frame 110 in the permanent magnet 423, and the magnetic field bends after passing through the permanent magnet 423 and extends outwardly in the radial direction of the rotor frame 110 through the rotor frame subsection 413 to reach the N pole corresponding to the rotor frame subsection 413. Based on the above description of the directions and orientations of the magnetic field in the rotor frame sub-sections 411 , 412 and 413 and the permanent magnets 422 and 423 , the directions and orientations of the magnetic field in other rotor frame sub-sections and permanent magnets can be understood by comparison.

[0041] Figure 5 FIG. 1 shows a cross-sectional view of a rotor frame 110 according to another embodiment of the present invention. Figure 5 In the illustrated embodiment, the gate head 530 has a circular cross section. Accordingly, the gate of the mold for casting the rotor frame 110 also has a circular cross section. From the perspective of mold processing and manufacturing, the difficulty of processing a circular gate is less than that of the above-mentioned narrow and long gate. However, the circular gate is generally farther from the outer circumference of the rotor frame 110 than the narrow and long gate, so during casting or injection molding, the strength of the external magnetic field to which the material used for casting, such as plastic ferrite, is subjected is smaller than that of the above-mentioned narrow and long gate, and the uniformity of the orientation arrangement of the magnetic particles is smaller than that of the narrow and long gate.

[0042] The present invention also provides a permanent magnet synchronous motor, which includes the rotor according to the embodiment of the present invention. The permanent magnet synchronous motor may also be a brushless DC motor, for example.

[0043] The utility model also proposes a mold. The mold is used for casting or injection molding a rotor frame of a rotor according to an embodiment of the utility model. The mold is hollow, the outer contour of the mold is configured as a hollow cylinder, the mold has a plurality of spacing grooves along the circumferential direction, and the mold is divided into a plurality of mold sub-parts by the spacing grooves; wherein the mold sub-parts have a gate, the gate is located on the end face of the mold, and the gate is closer to the outer circumference of the mold than the inner circumference of the mold, wherein the position of the gate corresponds to the position of the gate head of the rotor frame.

[0044] In this document, unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the utility model belongs. The words "first", "second" and similar words used in the patent application specification and claims of the utility model do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not necessarily indicate quantity restrictions. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0045] The exemplary implementation scheme of the scheme proposed in the utility model is described in detail above with reference to the preferred embodiments. However, it can be understood by those skilled in the art that, without departing from the concept of the utility model, various modifications and variations can be made to the above-mentioned specific embodiments, and various technical features and structures proposed in the utility model can be combined in various ways without exceeding the protection scope of the utility model, which is determined by the attached claims.

Claims

1. A rotor, characterized in that: The rotor comprises a rotor frame and permanent magnets; The rotor frame is configured as a hollow cylinder, the rotor frame has a plurality of spacing grooves along a circumferential direction, and the rotor frame is divided into a plurality of rotor frame sub-parts by the spacing grooves; The permanent magnets are arranged in the spacing slots; The rotor frame is integrally cast through a gate, the rotor frame sub-portion has a gate head corresponding to the gate, the gate head is located at the end surface of the rotor frame, and the gate head is closer to the outer circumference of the rotor frame than the inner circumference of the rotor frame.

2. The rotor according to claim 1, characterized in that Each rotor frame subsection has a respective gate spigot, the number of which is equal to the number of poles of the rotor.

3. The rotor according to claim 1, characterized in that The gate spigot has a cross section that is elongated in a circumferential direction, and the gate spigot extends to an outer circumference of the rotor frame.

4. The rotor according to claim 3, characterized in that The maximum length of the cross section elongated in the circumferential direction in the circumferential direction is more than twice the maximum length in the radial direction.

5. The rotor according to claim 3, characterized in that The cross section of the gate nozzle forms a fan ring, the outer arc of the fan ring has the same curvature as the outer circumference of the rotor frame, and the gate nozzle is located on the outer circumference of the rotor frame.

6. The rotor according to claim 1, characterized in that The gate tip has a circular cross section.

7. The rotor according to claim 1, characterized in that The gate head protrudes from the end surface of the rotor frame.

8. The rotor according to claim 1, characterized in that The material of the rotor frame is plastic ferrite.

9. The rotor according to claim 1, characterized in that The spacing groove is used to accommodate a magnetic field applying device during the orientation and magnetization process, so that the rotor frame obtains permanent magnetism; wherein the rotor frame sub-portion has a magnetic field direction extending along the radial direction of the rotor frame, and the rotor frame sub-portions on both sides of the spacing groove have opposite magnetic field directions respectively; wherein the magnetic field direction of the permanent magnet extends along the circumferential direction of the rotor frame; and The magnetic field of the permanent magnet in the spacing slot and the magnetic field of the rotor frame on both sides of the spacing slot together form a continuous magnetic circuit with the shortest path.

10. The rotor according to claim 1, characterized in that The spacing groove penetrates the rotor frame along the longitudinal direction of the rotor frame. The cross section of the spacing groove is configured as a trapezoid, and the lower base of the trapezoid cross section is close to the inner circumference of the rotor frame.

11. A permanent magnet synchronous motor, characterized in that: The permanent magnet synchronous machine comprises a rotor according to any one of the preceding claims.

12. A mold for casting a rotor frame of a rotor according to any one of claims 1 to 10, characterized in that: The mold is hollow, the outer contour of the mold is configured as a hollow cylinder, the mold has a plurality of spacing grooves along the circumferential direction, and the mold is divided into a plurality of mold sub-parts by the spacing grooves; The mold sub-section has a gate, which is located at an end surface of the mold and is closer to an outer circumference of the mold than to an inner circumference of the mold, wherein the position of the gate corresponds to the position of a gate nozzle of the rotor frame.

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