CN116937923A - Self-starting synchronous reluctance motor rotor assembly, manufacturing method thereof and motor - Google Patents

Abstract

The application provides a self-starting synchronous reluctance motor rotor assembly, a manufacturing method and a motor, wherein the motor rotor assembly comprises a squirrel cage connecting structure and a rotor core formed by a plurality of punching sheets in a split mode: the plurality of punching sheet split bodies are sequentially arranged at intervals along the Q-axis direction of the rotor assembly, and the intervals between two adjacent punching sheet split bodies respectively form slit air grooves communicated along the D-axis direction of the rotor assembly; the squirrel-cage connecting structure comprises end rings arranged corresponding to the outer sides of the end parts of the rotor iron cores and a plurality of first guide bars connected between the two end rings, wherein the first guide bars pass through each slit air groove so that each punching sheet is connected into a whole in a split mode; the slit air grooves are internally provided with heat dissipation holes, and the first conducting bars comprise outer conducting bars and inner conducting bars. The application can increase the reluctance effect of the Q axis, increase the inductance difference value of the dq axis, and increase the salient pole ratio, thereby improving the motor efficiency.

Description

Self-starting synchronous reluctance motor rotor assembly, manufacturing method thereof and motor

Technical Field

The application belongs to the technical field of motors, and particularly relates to a self-starting synchronous reluctance motor rotor assembly, a manufacturing method and a motor.

Background

The direct-starting synchronous reluctance motor combines the structural characteristics of an asynchronous motor and a synchronous reluctance motor, realizes starting by generating moment through squirrel cage induction, realizes constant-speed operation by generating reluctance torque through rotor inductance difference, and can realize starting operation by directly inputting a power supply. Compared with a direct-start permanent magnet motor, the direct-start synchronous reluctance motor has no rare earth permanent magnet material, no demagnetization problem, low motor cost and good reliability; compared with an asynchronous motor, the motor has high efficiency and constant rotating speed. The direct start synchronous reluctance motor can be started by itself without the need of a controller for starting, and the cost is further reduced.

The self-starting motor generates starting torque by cutting a stator magnetic field through a rotor conducting bar, and the rotor conducting bar is made of an electric conduction non-magnetic conduction material, usually pure aluminum and is filled in a high-pressure casting mode. After casting aluminum, end rings are formed at two ends of the rotor to short-circuit all or part of the conducting bars.

The rotor core is provided with a plurality of groups of identical air grooves, and the number of the air groove groups is the number of rotor poles; according to the shape of the air groove, the radial direction parallel to the air groove is called D-axis, and the radial direction perpendicular to the air groove is called Q-axis; the air groove is divided into a plurality of layers along the Q axis; each layer of air groove is divided into a D-axis aluminum casting groove, a Q-axis aluminum casting groove and a non-aluminum casting groove; the cast aluminum slots and the non-cast aluminum slots are separated by an inner magnetic bridge; the air slots and the rotor outer circle are separated by an outer magnetic bridge.

Because the rotor core is provided with a plurality of groups of grooves, the rotor structure strength is generally lower, and only the magnetic bridge is difficult to meet the structure strength requirement when the motor rotates at a high speed, on the other hand, the magnetic bridge is also used for limiting the flow direction of aluminum liquid when aluminum is cast and ensuring the shape of the conducting bars, but because the existing self-starting synchronous reluctance motor rotor core has the magnetic bridge structure (shown in fig. 5), magnetic force lines can form a magnetic leakage path through the magnetic bridges, so that the salient pole ratio is influenced, and the motor efficiency is reduced.

Disclosure of Invention

Therefore, the application provides a rotor assembly of a self-starting synchronous reluctance motor, a manufacturing method and a motor, which can solve the technical problems that in the prior art, a rotor core of the self-starting synchronous reluctance motor is based on the requirement of the structural strength of the rotor, a magnetic bridge structure is reserved, magnetic lines of force form magnetic leakage at the position where the magnetic bridge is arranged, and the motor efficiency is reduced.

In order to solve the above problems, the present application provides a rotor assembly of a self-starting synchronous reluctance motor, which comprises a squirrel cage connecting structure and a rotor core formed by a plurality of punching sheets in a split manner:

the punching sheet split bodies are sequentially arranged at intervals along the Q-axis direction of the rotor assembly, and the intervals between two adjacent punching sheet split bodies respectively form slit air grooves penetrating along the D-axis direction of the rotor assembly;

the squirrel-cage connecting structure comprises end rings and a plurality of first guide bars, wherein the end rings are arranged at the outer sides of the end parts of the rotor core, the first guide bars are connected between the two end rings, the first guide bars penetrate through the slit air grooves to enable the punching sheets to be connected into a whole in a split mode, the slit air grooves penetrate through the two first guide bars, the two first guide bars are respectively positioned at the two ends of the length of the slit air grooves along the D axis, empty grooves are formed between the two first guide bars, and the squirrel-cage connecting structure is made of conductive non-magnetic metal materials.

In some embodiments of the present application, in some embodiments,

two of the punching sheet split bodies which are positioned at the outermost side in the Q axis direction are side split bodies, each side split body is provided with a side air groove, the two side air grooves are symmetrical relative to the D axis and are symmetrical relative to the Q axis, the squirrel cage connecting structure further comprises second guide bars connected between the two end rings, and each second guide bar penetrates through the side air grooves in a one-to-one correspondence mode.

In some embodiments of the present application, in some embodiments,

the punching sheet split bodies are provided with central split bodies, the central split bodies are provided with rotating shaft holes, the intersection point of the D shaft and the Q shaft is a first center, and the centers of the rotating shaft holes are overlapped with the first center.

In some embodiments of the present application, in some embodiments,

the two first guide bars of the same slit air groove are symmetrical about the Q axis, the first distance between the side wall of one side of each first guide bar, which is close to the center of the rotor core, and the Q axis is smaller and smaller along the direction of the Q axis from the radial direction of the rotor core outwards, and the first distance is the farthest distance between the side wall of one side of each first guide bar, which is close to the center of the rotor core, and the Q axis in the direction parallel to the D axis.

In some embodiments of the present application, in some embodiments,

the rotor core is provided with 2N slit air grooves, the 2N slit air grooves are symmetrical about the D axis, the first distance of the first conducting bars in each slit air groove is L1, …, li, … and LN respectively along the Q axis in the radial outward direction of the rotor core on one magnetic pole of the rotor core, i is a natural number from 1 to N, the diameter of the outer circle of the rotor core is Dr, and the diameter of the outer circle of the rotor core is more than or equal to 0.15 and less than or equal to 2Li/Dr is less than or equal to 0.75.

In some embodiments of the present application, in some embodiments,

the rotor core is characterized in that rotor baffles are arranged at two axial ends of the rotor core, the rotor baffles are clamped between the end face of the rotor core and the end ring, and casting through holes are formed in the rotor baffles at positions corresponding to the end parts of the empty slots and the side air slots.

In some embodiments of the present application, in some embodiments,

the casting through holes corresponding to the end portions of the same empty slot have inner side hole walls near the center side of the rotor core, and ventilation gaps are formed between the inner side hole walls and the first conducting bars.

In some embodiments of the present application, in some embodiments,

the end ring comprises an inner ring wall and an outer ring wall concentric with a rotating shaft hole of the rotor core, the projection of the side wall of one side of each first conducting bar, which is close to the center of the rotor core, in any plane perpendicular to the axis of the rotor core is a straight line parallel to the Q axis, the inner ring wall is provided with a straight line inner wall parallel to the side wall of one side of each slit air groove, which is close to the center of the rotor core, at the position corresponding to each slit air groove, the distance between the straight line inner wall and the Q axis is a second distance, and the second distances between the straight line inner wall corresponding to each slit air groove and the Q axis are respectively Le1, …, lei, … and LeN, and Lei is more than or equal to Li.

In some embodiments of the present application, in some embodiments,

0.15≤2Lei/Dr≤0.75。

in some embodiments of the present application, in some embodiments,

the outer diameter of the end ring is D, D/Dr is less than or equal to 1, and D/Dr is more than or equal to Dsft/Dr; and/or the number of the groups of groups,

the axial height of the end ring is Ht, and the axial height of the rotor core is H, wherein Ht/H is more than 0.5 and is more than or equal to 0.05.

In some embodiments of the present application, in some embodiments,

the squirrel-cage connecting structure is formed by die casting.

The application also provides a manufacturing method of the self-starting synchronous reluctance motor rotor assembly, which comprises the following steps:

placing each rotor baffle plate and each punching sheet in a die-casting mold according to the target position of each rotor baffle plate and each punching sheet in the rotor iron core, wherein the die-casting mold comprises an outer cylinder body correspondingly matched with the outer circumferential wall of the rotor iron core, supporting strips correspondingly matched with the shape of each ventilation gap and an inner cylinder body correspondingly matched with the radial outer side of each supporting strip;

inserting each supporting bar into the forming position of each ventilation gap correspondingly;

and injecting an electric conduction non-magnetic conduction metal material into a region formed between the outer cylinder body and the inner cylinder body, after the injected electric conduction non-magnetic conduction metal material is solidified and molded, extracting each supporting bar from the rotor core, and taking out the molded self-starting synchronous reluctance motor rotor assembly from the mold.

The application also provides a motor, which comprises the self-starting synchronous reluctance motor rotor assembly.

The rotor assembly of the self-starting synchronous reluctance motor, the manufacturing method and the motor provided by the application have the following beneficial effects:

the rotor core is provided with a plurality of punching sheets which are assembled in a split mode, and the connection of the punching sheets in a squirrel cage connection structure is used as a lower mode to form an organic whole, so that each stacked punching sheet of the rotor core does not need to keep a magnetic bridge in the prior art and also has higher structural strength, and magnetic leakage of a magnetic circuit at the position of the magnetic bridge can be reduced because the magnetic bridge in the prior art is not kept, the reluctance effect of a Q axis can be improved, the inductance difference value of a dq axis is increased, the salient pole ratio is increased, and the motor efficiency is further improved; unlike the punched sheets of integral structure adopted in the rotor assembly of the self-starting synchronous reluctance motor in the prior art, the rotor punched sheet is formed by mutually assembling a plurality of punched sheets in a separated mode, so that the consumption of silicon steel sheets can be reduced, and the manufacturing cost is reduced; the first conducting bar can improve the self-starting performance of the motor rotor.

The first guide bars are arranged at the two ends of each slit air groove, the hollow grooves are arranged at the middle positions, the first guide bars at the two ends can improve the self-starting performance of the motor rotor, the corresponding guide bar structures are not arranged at the middle positions of the slit air grooves, and the hollow grooves can reduce vortex generation at the positions and improve the motor performance.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It will be apparent to those skilled in the art from this disclosure that the drawings described below are merely exemplary and that other embodiments may be derived from the drawings provided without undue effort.

The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the application, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present application, should fall within the ambit of the technical disclosure.

FIG. 1 is a schematic view (axial projection) of a rotor core in a self-starting synchronous reluctance motor rotor assembly according to an embodiment of the present application;

FIG. 2 is a schematic internal cross-sectional view of a self-starting synchronous reluctance motor rotor assembly according to an embodiment of the present application;

FIG. 3 is an axial projection schematic view of a rotor assembly of a self-starting synchronous reluctance motor according to an embodiment of the present application;

FIG. 4 is an axial cross-sectional schematic view of a self-starting synchronous reluctance motor rotor assembly according to an embodiment of the present application;

FIG. 5 is a schematic diagram (axial projection) of a rotor core of a prior art self-starting synchronous reluctance motor rotor assembly having a magnetic bridge;

FIG. 6 is a graph of the starting capability of a self-starting synchronous reluctance motor rotor assembly according to an embodiment of the present application;

FIG. 7 is a graph comparing motor efficiency with a self-starting synchronous reluctance motor rotor assembly (without a magnetic bridge) and without a magnetic bridge employing the present application;

FIG. 8 is a graph comparing rotor strength (safety factor) for a self-starting synchronous reluctance motor rotor assembly (without magnetic bridge) with a rotor strength (with magnetic bridge) without magnetic bridge according to the present application;

fig. 9 is a schematic diagram (axial projection) of a rotor baffle of a rotor assembly of a self-starting synchronous reluctance motor according to an embodiment of the present application.

The reference numerals are expressed as:

10. the punching sheet is split; 101. side-to-side split; 102. a central split; 1021. a rotation shaft hole;

201. slit air groove; 202. a side air groove; 203. a hollow groove;

301. an end ring; 302. a first guide bar; 303. a second guide bar;

4. a rotor baffle; 41. and casting the through hole.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

It should be understood that the term "and/or" as used herein is merely one relationship describing the association of the associated objects, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present application, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present application and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present application; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present application.

Referring to fig. 1 and 9 in combination, according to an embodiment of the present application, a rotor assembly of a self-starting synchronous reluctance motor is provided, which includes a squirrel cage connection structure (not indexed in the drawings) and a rotor core (not indexed in the drawings) formed by a plurality of lamination sub-units 10, specifically, each lamination sub-unit 10 corresponding to the same position is stacked as a whole in an axial direction of the rotor core: wherein, in a radial plane of the rotor core (i.e. a plane perpendicular to a rotating shaft of the rotor core), a plurality of the punching sheet split bodies 10 are sequentially arranged at intervals along a Q-axis (as shown in fig. 1) direction of the rotor assembly, and the intervals between two adjacent punching sheet split bodies 10 respectively form slit air grooves 201 penetrating along the D-axis (as shown in fig. 1) direction of the rotor assembly; referring to fig. 1, the respective punch segments 10 are symmetrical about the Q axis, the number of the punch segments 10 disposed at both sides of the D axis is equal, and the positions thereof are correspondingly symmetrical about the D axis, and similarly, the respective slit air slots 201 are symmetrical about the Q axis, and the number of the respective slit air slots 201 disposed at both sides of the D axis is equal, and the positions thereof are correspondingly symmetrical about the D axis, taking the two-pole rotor core shown in fig. 1 as an example, the Q axis and the D axis are orthogonal to each other, and it can be understood that the outer peripheral wall of each punch segment 10 in the same radial plane is cylindrical after the lamination according to the preset positions is completed; the squirrel-cage connecting structure comprises end rings 301 (specifically, two end rings 301 are arranged corresponding to the outer sides of the ends of the rotor core, and one end ring corresponds to each end of the rotor core) and a plurality of first guide bars 302 connected between the two end rings 301, wherein the plurality of first guide bars 302 pass through each slit air groove 201 so that each punching split body 10 is connected into a whole; two first conducting bars 302 pass through each slit air groove 201, the two first conducting bars 302 are respectively positioned at two ends of the length of the slit air groove 201 along the D axis, an empty groove 203 is formed between the two first conducting bars 302, and the squirrel cage connecting structure is made of conductive non-magnetic metal materials. It can be understood that the motor rotor is not provided with corresponding magnetic steel grooves and magnetic steel.

In the technical scheme, the rotor core is assembled by the plurality of punching sheet split bodies 10, and the connection of the punching sheet split bodies 10 under the squirrel cage connection structure is used as an organic whole, so that each stacked punching sheet of the rotor core does not need to keep a magnetic bridge in the prior art and also has higher structural strength, and magnetic leakage of a magnetic circuit at the position of the magnetic bridge can be reduced because the magnetic bridge in the prior art is not kept, thus the reluctance effect of a Q axis can be increased, the inductance difference value of a dq axis is increased, the salient pole ratio is increased, and the motor efficiency is further improved; unlike the punched sheet of integral structure adopted in the rotor assembly of the self-starting synchronous reluctance motor in the prior art, the rotor punched sheet is formed by mutually assembling and combining a plurality of punched sheet split bodies 10 at intervals, so that the consumption of silicon steel sheets can be reduced, and the manufacturing cost is reduced; in this technical solution, the first conducting bars 302 are disposed at two ends of each slit air slot 201, and the hollow slots 203 are disposed at the middle positions, the first conducting bars 302 at two ends can improve the self-starting performance of the motor rotor, the corresponding conducting bar structures are not disposed at the middle positions of the slit air slots 201, and the hollow slots 203 can reduce the eddy current generation at the positions, thereby improving the motor performance. The empty slot 203 is occupied by air.

In a preferred embodiment, the squirrel cage connecting structure is specifically molded by die casting an electrically conductive and magnetically non-conductive metal material, preferably, the electrically conductive and magnetically non-conductive metal material may be aluminum or copper, preferably, aluminum, which has a smaller density, and the magnetic permeability of the squirrel cage connecting structure is similar to that of air, so that the magnetic resistance effect of the Q axis can be increased.

With continued reference to fig. 1, in some embodiments, two of the punch segments 10 located at the outermost sides in the Q axis direction are side segments 101, each side segment 101 has a side air slot 202 thereon, the two side air slots 202 are symmetrical about the D axis and symmetrical about the Q axis, and the squirrel cage connection structure further includes second guide bars 303 connected between two end rings 301, where each second guide bar 303 runs through the side air slot 202 in a one-to-one correspondence.

In this technical scheme, through constructing the side air tank 202 on the side components of a whole that can function independently 101, the reluctance effect of Q axle can be further increased, the inductance difference of dq axle is increased, increase the salient pole ratio, and then improve motor efficiency, and the aforesaid second conducting bar 303 of passing through is arranged in the side air tank 202 need not to design alone the equipment of side components of a whole that can function independently 101, has promoted motor rotor's compactibility.

In some embodiments, the side split 101 has an outer arc-shaped magnetic bridge, and by setting the outer arc-shaped magnetic bridge, the positioning of the side split 101 in the process of manufacturing the motor rotor can be facilitated, and the manufacturing process is facilitated.

With continued reference to fig. 1, in some embodiments, each of the punch segments 10 has a central segment 102, where a rotation shaft hole 1021 is configured on the central segment 102, an intersection point of the D axis and the Q axis is a first center, and a center of the rotation shaft hole 1021 coincides with the first center.

In this technical scheme, the rotation shaft hole 1021 is configured on the central split body 102, so that the structural configuration of the rotor core is more reasonable.

In some embodiments, the two first guide bars 302 of the same slot air groove 201 are symmetrical about the Q axis, and a first distance between a side wall of the first guide bar 302 near the center of the rotor core and the Q axis, which is the farthest distance between a side wall of the first guide bar 302 near the center of the rotor core and the Q axis in a direction parallel to the D axis, is smaller and smaller along a direction of the Q axis radially outward from the rotor core. Specifically, the rotor core has 2N slit air grooves 201,2N, the slit air grooves 201 are symmetrical about the D axis, the first distances of the first conductive bars 302 in each slit air groove 201 are one natural number of L1, …, li, …, LN, i, and 1 to N, respectively, on one magnetic pole of the rotor core, along the Q axis from the radial direction of the rotor core to the outside, the outer circle diameter of the rotor core is Dr,0.15 is equal to or less than 2Li/Dr is equal to or less than 0.75, taking the specific embodiment shown in fig. 2 as an example, where n=4, that is, the slit air grooves 201 are provided on the rotor core in total, and the upper and lower regions of the rotor core have 4 pieces, respectively, with the D axis as the symmetry axis. Referring specifically to fig. 6, when 2Li/Dr is between 0.15 and 0.75, the starting performance of the motor rotor is in a high range.

Referring to fig. 9, in some embodiments, rotor baffles 4 are disposed at two axial ends of the rotor core, the rotor baffles 4 are clamped between an end face of the rotor core and the end ring 301, and casting through holes 41 are disposed on the rotor baffles 4 at positions corresponding to the end portions of the empty slots 203 and the side air slots 202.

In the technical scheme, before the rotor core is formed and prepared, each punching split body 10 can be preassembled between two rotor baffles 4 according to the target position, so that the position of each punching split body can be determined before being placed in a corresponding die, the preparation efficiency is improved, the squirrel cage connecting structure can be formed by casting aluminum liquid into the casting through hole 41, and the preparation process is simple and easy to implement.

In some embodiments, the casting through hole 41 corresponding to the end of the same empty slot 203 has an inner hole wall near the center side of the rotor core, and a ventilation gap is formed between the inner hole wall and the first guide bar 302. In the preparation process of the motor rotor, corresponding support bars are inserted into the ventilation gaps before casting the aluminum liquid, occupation is formed at the positions, then the aluminum liquid is cast, and each support bar is extracted from the corresponding support bar after solidification of the cast aluminum liquid, so that the ventilation gaps are formed.

The ventilation gap is used as an axial airflow circulation channel of the motor rotor on one hand, can timely disperse heat in the rotor core, effectively controls temperature rise in the running process of the motor rotor, and is used as a casting separation area of the first guide bar 302 and the empty groove 203 on the other hand, so that the squirrel cage connecting structure of the application forms squirrel cage characteristics, and the rotor is ensured to have self-starting capability.

In some embodiments, the end ring 301 includes an inner ring wall and an outer ring wall concentric with the rotation shaft hole 1021 of the rotor core, where a projection of a side wall of each first conducting bar 302 near a center of the rotor core in any plane perpendicular to an axis of the rotor core is a straight line parallel to the Q axis, the inner ring wall has, at a position corresponding to each slit air groove 201, a straight line inner wall parallel to a side wall of each first conducting bar 302 near the center of the rotor core, a distance between the straight line inner wall and the Q axis is a second distance, and the second distances between the straight line inner wall corresponding to each slit air groove 201 and the Q axis are Le1, …, lei, …, leN, lei being equal to Li, respectively. The inner walls of the straight lines at the two adjacent ends can be connected through smooth arcs or straight lines.

When Lei is larger than Li, the inner annular wall of the end ring 301 forms the aforementioned ventilation gap with the radially inner side wall of the casting through hole 41 of the rotor baffle 4, so as to ensure the ventilation and heat dissipation effects of the ventilation gap. In one preferred embodiment, 0.15.ltoreq.2 Lei/Dr.ltoreq.0.75 in some embodiments.

In some embodiments of the present application, in some embodiments,

the outer diameter of the end ring 301 is D, D/Dr is less than or equal to 1, and D/Dr is greater than or equal to Dsft/Dr, so that the end ring 301 is located within the end face entity range of the rotor core, and no adverse obstacle is caused to subsequent shaft penetration, and meanwhile, the width of the air gap between stator rotations is not affected.

The axial height of the end ring 301 is Ht, the axial height of the rotor core is H, and 0.5 > Ht/H is more than or equal to 0.05, so that the volume of the end ring 301 is larger, the resistance of a squirrel cage connecting structure is reduced, and the starting capability of the motor is further improved.

As shown in fig. 7, the motor performance of the motor rotor without the magnetic bridge of the present application can be improved by at least 1.8% by testing the motor efficiency of the motor rotor with the magnetic bridge of the prior art and the motor rotor without the magnetic bridge of the present application.

As shown in fig. 8, the strength of the rotor of the motor with a magnetic bridge in the prior art and the strength of the rotor of the motor without a magnetic bridge in the application are tested, and the strength of the rotor of the motor without a magnetic bridge in the application is remarkably improved, so that the safety coefficient is improved to more than 1.6, and the safety coefficient in the prior art is only about 1.2.

According to an embodiment of the present application, there is also provided a method for manufacturing the self-starting synchronous reluctance motor rotor assembly, including the steps of:

placing each rotor baffle 4 and each punching split body 10 in a die casting die according to various target positions in the rotor core, wherein the die casting die comprises an outer cylinder body correspondingly matched with the outer circumferential wall of the rotor core, supporting strips correspondingly matched with the shape of each ventilation gap and an inner cylinder body correspondingly matched with the radial outer side of each supporting strip, specifically, the outer cylinder body is matched with the outer circumferential wall of the rotor core in a fitting way, the inner diameter of the outer cylinder body is Dr, the inner cylinder body is matched with the inner circumferential wall of a rotating shaft hole 1021 in a fitting way, the outer diameter of the inner cylinder body is Dsft, a circular ring area is formed between the outer cylinder body and the outer cylinder body, and each punching split body 10 and each supporting strip are assembled in the area;

inserting each supporting bar into the forming position of each ventilation gap correspondingly;

and injecting an electric conduction and non-magnetic conduction metal material into the annular area formed between the outer cylinder body and the inner cylinder body, solidifying and forming the injected electric conduction and non-magnetic conduction metal material, drawing out each support bar from the rotor core, and taking out the formed rotor assembly of the self-starting synchronous reluctance motor from the die.

In the technical scheme, the rotor core of the self-starting synchronous reluctance motor rotor assembly is formed according to the manufacturing method, the rotor core is assembled by a plurality of punching sheet split bodies 10, and each punching sheet split body 10 is connected with a squirrel cage connecting structure to form an organic whole, so that each stacked punching sheet of the rotor core has higher structural strength without retaining a magnetic bridge in the prior art, and magnetic circuit magnetic flux leakage at the position of the magnetic bridge can be reduced because the magnetic bridge in the prior art is not retained, so that the reluctance effect of a Q-axis can be increased, the inductance difference value of a dq-axis is increased, the salient pole ratio is increased, and the motor efficiency is further improved; unlike the punched sheet of integral structure adopted in the rotor assembly of the self-starting synchronous reluctance motor in the prior art, the rotor punched sheet is formed by mutually and separately assembling a plurality of punched sheet split bodies 10, so that the consumption of silicon steel sheets can be reduced, and the manufacturing cost is reduced; the first guide bars 302 are disposed at two ends of each slit air groove 201 and the hollow groove 203 is disposed at the middle position, the first guide bars 302 at two ends can improve the self-starting performance of the motor rotor, and the hollow groove 203 is disposed at the middle position of the slit air grooves 201 without providing corresponding guide bar structures, so that the generation of vortex at the position can be reduced, and the motor performance can be improved.

According to an embodiment of the present application, there is also provided an electric machine including the self-starting synchronous reluctance motor rotor assembly described above.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application. The foregoing is merely a preferred embodiment of the present application, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the technical principles of the present application, and these modifications and variations should also be regarded as the scope of the application.

Claims (13)

1. The rotor assembly of the self-starting synchronous reluctance motor is characterized by comprising a rotor core formed by a squirrel cage connecting structure and a plurality of punching sheet split bodies (10):

the punching sheet split bodies (10) are sequentially arranged at intervals along the Q-axis direction of the rotor assembly, and slit air grooves (201) penetrating along the D-axis direction of the rotor assembly are respectively formed at intervals between two adjacent punching sheet split bodies (10);

the squirrel-cage connecting structure comprises end rings (301) arranged on the outer sides of the end parts of the rotor iron cores and a plurality of first conducting bars (302) connected between the two end rings (301), wherein the first conducting bars (302) penetrate through each slit air groove (201) to enable each punching sheet split body (10) to be connected into a whole, each slit air groove (201) penetrates through two first conducting bars (302), the two first conducting bars (302) are respectively positioned at two ends of the length of the slit air grooves (201) along the D axis, empty grooves (203) are formed between the two first conducting bars (302), and the squirrel-cage connecting structure is made of conductive non-magnetic metal materials.

2. The self-starting synchronous reluctance machine rotor assembly according to claim 1, wherein,

two of the punching sheet split bodies (10) located at the outermost side of the Q axis direction are side split bodies (101), each side split body (101) is provided with a side air groove (202), the two side air grooves (202) are symmetrical about the D axis and symmetrical about the Q axis, the squirrel cage connecting structure further comprises second guide strips (303) connected between the two end rings (301), and the second guide strips (303) correspondingly penetrate through the side air grooves (202) one by one.

3. The self-starting synchronous reluctance machine rotor assembly according to claim 1, wherein,

each punching sheet split body (10) is provided with a central split body (102), the central split body (102) is provided with a rotating shaft hole (1021), the intersection point of the D shaft and the Q shaft is a first center, and the center of the rotating shaft hole (1021) coincides with the first center.

4. The self-starting synchronous reluctance machine rotor assembly according to claim 1, wherein,

the two first guide strips (302) of the same slit air groove (201) are symmetrical about the Q axis, a first distance between a side wall of one side of each first guide strip (302) close to the center of the rotor core and the Q axis along the Q axis in a direction from the radial outside of the rotor core is smaller and smaller, and the first distance is the farthest distance between a side wall of one side of each first guide strip (302) close to the center of the rotor core and the Q axis in a direction parallel to the D axis.

5. The self-starting synchronous reluctance machine rotor assembly according to claim 4,

the rotor core is provided with 2N slit air grooves (201), the 2N slit air grooves (201) are symmetrical about the D axis, the first distance between the first conducting bars (302) in each slit air groove (201) along the Q axis in the radial outward direction of the rotor core is respectively L1, …, li, … and LN, i is one natural number of 1 to N, and the outer circle diameter of the rotor core is Dr and is more than or equal to 0.15 and less than or equal to 2Li/Dr and less than or equal to 0.75.

6. The self-starting synchronous reluctance machine rotor assembly according to claim 5,

rotor baffle (4) are arranged at two axial ends of the rotor core, the rotor baffle (4) is clamped between the end face of the rotor core and the end ring (301), and casting through holes (41) are formed in positions, corresponding to the end parts of the empty slots (203) and the side air slots (202), of the rotor baffle (4).

7. The self-starting synchronous reluctance machine rotor assembly according to claim 6, wherein,

the casting through hole (41) corresponding to the end of the same empty slot (203) has an inner side hole wall near the center side of the rotor core, and a ventilation gap is formed between the inner side hole wall and the first conducting bar (302).

8. The self-starting synchronous reluctance machine rotor assembly according to claim 5,

the end ring (301) comprises an inner annular wall and an outer annular wall concentric with a rotating shaft hole (1021) of the rotor core, the projection of the side wall of each first conducting bar (302) close to the center of the rotor core on any plane perpendicular to the axis of the rotor core is a straight line parallel to the Q axis, the inner annular wall is provided with a straight line inner wall parallel to the side wall of each slit air groove (201) of each first conducting bar (302) close to the center of the rotor core, the distance between the straight line inner wall and the Q axis is a second distance, and the second distances between the straight line inner wall corresponding to each slit air groove (201) and the Q axis are Le1, …, lei, … and LeN respectively, and Lei is more than or equal to Li.

9. The self-starting synchronous reluctance machine rotor assembly according to claim 8,

0.15≤2Lei/Dr≤0.75。

10. the self-starting synchronous reluctance machine rotor assembly according to claim 9,

the outer diameter of the end ring (301) is D, D/Dr is less than or equal to 1, and D/Dr is more than or equal to Dsft/Dr; and/or the number of the groups of groups,

the axial height of the end ring (301) is Ht, and the axial height of the rotor core is H, wherein 0.5 > Ht/H is more than or equal to 0.05.

11. The self-starting synchronous reluctance machine rotor assembly according to claim 1, wherein,

the squirrel-cage connecting structure is formed by die casting.

12. A method of manufacturing a self-starting synchronous reluctance machine rotor assembly according to any one of claims 1 to 11, comprising the steps of:

placing each rotor baffle (4) and each punching split (10) in a die casting mold according to the target position of each punching split in the rotor core, wherein the die casting mold comprises an outer cylinder body correspondingly matched with the outer circumferential wall of the rotor core, supporting strips correspondingly matched with the shape of each ventilation gap and an inner cylinder body correspondingly matched with the radial outer side of each supporting strip;

inserting each supporting bar into the forming position of each ventilation gap correspondingly;

and injecting an electric conduction non-magnetic conduction metal material into a region formed between the outer cylinder body and the inner cylinder body, after the injected electric conduction non-magnetic conduction metal material is solidified and molded, extracting each supporting bar from the rotor core, and taking out the molded self-starting synchronous reluctance motor rotor assembly from the mold.

13. An electric machine, which is characterized in that,

a self-starting synchronous reluctance motor rotor assembly comprising any one of claims 1 to 11.