CN116937924A - 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 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 penetrate through the slit air grooves so that the punching sheets are connected into a whole in a split mode;

each slit air groove is internally provided with a heat dissipation hole, the heat dissipation holes extend along the axial direction of the rotor core and penetrate through the two end rings, the first conducting bars comprise outer conducting bars positioned on the first side of the heat dissipation holes and inner conducting bars positioned on the second side of the heat dissipation holes, the first side is the side, far away from the axis of the rotor core, of the heat dissipation holes, the second side is the side, close to the axis of the rotor core, of the heat dissipation holes, and the squirrel cage connecting structure is made of an electric conduction non-magnetic conduction metal material.

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,

and each slit air groove is provided with two radiating holes which are symmetrical about the Q axis.

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

along the radial outward direction of the Q axis from the rotor core, a first distance between the wall of the first side of each heat dissipation hole and the Q axis is smaller and smaller, and the first distance is the farthest distance between the wall of the second side of the heat dissipation hole 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 between the heat dissipation holes in the slit air grooves along the Q axis and in the radial outward direction of the rotor core is Lm1, …, lmi, … and LmN respectively, i is a natural number from 1 to N, the outer circle diameter of the rotor core is Dr, and the outer circle diameter of the rotor core is more than or equal to 0.2 and less than or equal to 2Lmi/Dr is less than or equal to 0.8.

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

each layer of the slit air grooves has a groove extension center line, the distance between two points, at which the same heat dissipation hole intersects with the groove extension center line, of each of the heat dissipation holes in the slit air grooves is the width of the heat dissipation hole, on one magnetic pole of the rotor core, along the Q axis in the radial outward direction of the rotor core, the width of the heat dissipation hole in each of the slit air grooves is Wm1, …, wmi, …, wmN, i is one natural number of 1 to N, and Wmi is less than or equal to Lmi; and/or, 0.2.ltoreq.2 Wmi/Dr.ltoreq.0.8.

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

the projection of the radiating hole on any plane perpendicular to the axis of the rotor core is rectangular.

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

the end ring is in a ring shape concentric with the rotating shaft hole of the rotor core, and the radial width of the end ring isWherein Dr is an outer diameter of the rotor core, and Dsft is a diameter of the rotating shaft hole.

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 punching sheet in a die casting mold according to the target position of each punching sheet 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, an inner cylinder body correspondingly matched with the inner circumferential wall of a rotating shaft hole and supporting bars correspondingly matched with the shape of each heat dissipation hole;

inserting each supporting bar into the forming position of each heat dissipation hole 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, and after the injected electric conduction and 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 die.

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 comprises an outer conducting bar positioned on the first side of the radiating hole and an inner conducting bar positioned on the second side of the radiating hole, wherein the outer conducting bar can improve the self-starting performance of the motor rotor, and the inner conducting bar can improve the inertial mass of the rotor to a certain extent, so that the starting capability of the rotor can be enhanced to a certain extent.

It is worth emphasizing that the heat dissipation holes are used as axial airflow circulation channels of the motor rotor on one hand, heat in the rotor core can be timely dissipated, temperature rise in the running process of the motor rotor is effectively controlled, and on the other hand, the heat dissipation holes are used as separation areas of the outer side guide bars and the inner side guide bars, so that the squirrel-cage connecting structure of the application forms squirrel-cage characteristics, and the rotor is guaranteed to have self-starting capability.

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 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. 3 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. 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) of a self-starting synchronous reluctance motor rotor assembly (without magnetic bridge) with a rotor strength (with magnetic bridge) without using 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 heat radiation hole;

301. an end ring; 302. a first guide bar; 3021. an outer guide bar; 3022. an inner guide bar; 303. and a second conducting bar.

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 8 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; each slot air groove 201 has a heat dissipation hole 203 therein, the heat dissipation holes 203 extend along the axial direction of the rotor core and penetrate through the two end rings 301, the first conductive bars 302 include an outer conductive bar 3021 located at a first side of the heat dissipation holes 203 and an inner conductive bar 3022 located at a second side of the heat dissipation holes 203, the first side is a side of the heat dissipation holes 203 away from the axis of the rotor core, the second side is a side of the heat dissipation holes 203 near the axis of the rotor core, and it is noted that, for the in-groove region of each slot air groove 201, other regions are filled with the first conductive bars 302 except for the air magnetic isolation position of the heat dissipation holes 203, that is, the heat dissipation holes 203 in the present application are separate holes of the outer conductive bars 3021 and the inner conductive bars 3022, and the squirrel cage connecting structure is made of an electrically conductive and magnetically non-conductive metal material. 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; the first conducting bar 302 comprises an outer conducting bar 3021 positioned on the first side of the heat dissipation hole 203 and an inner conducting bar 3022 positioned on the second side, wherein the outer conducting bar 3021 can improve the self-starting performance of the motor rotor, and the inner conducting bar 3022 can improve the inertial mass of the rotor to a certain extent, which can also improve the starting capability of the rotor to a certain extent.

It should be emphasized that the heat dissipation holes 203 are used as axial airflow channels of the motor rotor, so as to timely dissipate heat in the rotor core, effectively control temperature rise in the running process of the motor rotor, and are used as separation areas of the outer guide strips 3021 and the inner guide strips 3022, so that the squirrel-cage connection structure of the application forms squirrel-cage characteristics, and the rotor is ensured to have self-starting capability.

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. In this case, before the foregoing casting of the motor rotor, a processing tool (for example, a die casting mold, a support bar, or the like described later) may be used to form a processing device, specifically, the support bar is inserted into a position where the corresponding heat dissipation hole 203 is located, and the outside guide bar 3021 and the inside guide bar 3022 are formed by preventing the area from entering the die casting material and allowing the die casting material to be split to other positions of the slot air groove 201 that are not occupied by the support bar.

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 a specific embodiment, each slit air groove 201 has two heat dissipation holes 203, and the two heat dissipation holes 203 are symmetrical about the Q axis.

In this technical solution, on the one hand, the two symmetrically arranged heat dissipation holes 203 can increase the axial flow area of the rotor core, and further utilize the improvement of the heat dissipation effect, and more importantly, the structures of the outer guide strips 3021 respectively located at the first sides of the heat dissipation holes 203 are symmetrical to each other, which is beneficial to promoting the stable start of the rotor core.

In some embodiments, a first distance between a wall of a first side of each of the heat dissipating holes 203 and the Q axis is smaller along a direction of the Q axis outward from a radial direction of the rotor core, the first distance being a farthest distance between a wall of a second side of the heat dissipating hole 203 and the Q axis in a direction parallel to the D axis. This ensures that each outer conductor 3021 has a certain width so that the corresponding resistance is not too great.

In some embodiments, the rotor core has 2N slit air slots 201,2N, the slit air slots 201 are symmetrical about the D axis, the first distance between the heat dissipation holes 203 in each slit air slot 201 is one natural number of Lm1, …, lmi, …, lmN, i being 1 to N, on one magnetic pole of the rotor core, along the Q axis from the radial direction of the rotor core, the outer circle diameter of the rotor core is Dr, 0.2+.2 2 Lmi/dr+.0.8, taking the specific example shown in fig. 2 as an example, where n=4, that is, the slit air slots 201 are provided with 8 on the rotor core, taking the D axis as the symmetry axis, and the upper and lower regions of the rotor core are each 4. Referring specifically to fig. 6, when 2Lmi/Dr is between 0.2 and 0.8, the starting performance of the motor rotor is in a high range.

With continued reference to fig. 2, in some embodiments, each layer of slot air slots 201 has a slot extension centerline, specifically, the specific shape of the slot extension centerline matches the shape of the corresponding slot air slot 201, which may have a straight line segment and a circular arc segment, for each slot air slot 201, the distance between two points where the same slot air slot 203 intersects with the slot extension centerline is the width of the slot air slot 203, on one magnetic pole of the rotor core, along the Q axis in the radial outward direction of the rotor core, the width of the slot air slot 203 in each slot air slot 201 is Wm1, …, wmi, …, wmN, i is a natural number from 1 to N, wmi is Lmi, at this time, the air slot portion and the bar filling portion (specifically, may be cast aluminum slot portion) of each slot air slot 201 are each generally occupied so that the inertia mass of the motor rotor is relatively large and the inertia of the motor is not excessively large, and the inertia of the motor is difficult to start the rotor; furthermore, the self-starting capacity of the motor rotor is further improved by not more than 0.2 Wmi/Dr not more than 0.8.

In some embodiments, the projection of the heat dissipation hole 203 on any plane perpendicular to the axis of the rotor core is rectangular, so as to reduce manufacturing difficulty. In the case where the process conditions are satisfied, the projection of the heat dissipation holes 203 on the plane may be other shapes that satisfy the requirements.

In some embodiments, the end ring 301 is in communication with the rotorThe spindle hole 1021 of the core is concentric with a circular ring shape, the radial width of the end ring 301 is W,the Dr is the diameter of the outer circle of the rotor core, the Dsft is the diameter of the rotation shaft hole 1021, and the end ring shape defined in this way can ensure that the motor rotor has better starting capability.

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 1.5% 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 be more than 2, 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 of the punching split bodies 10 in a die-casting mold according to the target position of each of the punching split bodies 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, an inner cylinder body correspondingly matched with the inner circumferential wall of the rotating shaft hole 1021 and supporting bars correspondingly matched with the shape of each of the heat dissipation holes 203, specifically, the outer cylinder body is in fit with the outer circumferential wall of the rotor core, the inner diameter of the outer cylinder body is Dr, the inner cylinder body is in fit with the inner circumferential wall of the rotating shaft hole 1021, the outer diameter of the inner cylinder body is Dsft, a circular ring area is formed between the outer cylinder body and the inner cylinder body, and each of the punching split bodies 10 and the supporting bars is assembled in the area;

inserting each supporting bar into the forming position of each heat dissipation hole 203 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, and after the injected electric conduction and 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 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 conducting bar 302 comprises an outer conducting bar 3021 positioned on the first side of the heat dissipation hole 203 and an inner conducting bar 3022 positioned on the second side, wherein the outer conducting bar 3021 can improve the self-starting performance of the motor rotor, and the inner conducting bar 3022 can improve the inertial mass of the rotor to a certain extent, which can also improve the starting capability of the rotor to a certain extent.

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 corresponding to the outer sides of the end parts of the rotor iron cores 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;

each slit air groove (201) is internally provided with a radiating hole (203), the radiating holes (203) extend along the axial direction of the rotor core and penetrate through the two end rings (301), the first guide bars (302) comprise outer guide bars (3021) positioned on the first side of the radiating holes (203) and inner guide bars (3022) positioned on the second side of the radiating holes (203), the first side is the side, far away from the axis of the rotor core, of the radiating holes (203), the second side is the side, close to the axis of the rotor core, of the radiating holes (203), and the squirrel cage connecting structure is made of an electric conductive and non-magnetic conductive metal material.

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,

two radiating holes (203) are respectively arranged in the same slit air groove (201), and the two radiating holes (203) are symmetrical about the Q axis.

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

the first distance between the wall of the first side of each heat dissipating hole (203) and the Q axis is smaller and smaller along the direction of the Q axis from the radial outward direction of the rotor core, and the first distance is the farthest distance between the wall of the second side of the heat dissipating hole (203) and the Q axis in the direction parallel to the D axis.

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

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 radiating holes (203) in the slit air grooves (201) along the Q axis and in the radial outward direction of the rotor core is respectively Lm1, …, lmi, … and LmN, 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 0.2 and less than or equal to 2Lmi/Dr and less than or equal to 0.8.

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

each layer of the slit air grooves (201) has a groove extension center line, the distance between two points where the same heat dissipation hole (203) intersects with the groove extension center line is the width of the heat dissipation hole (203) for the heat dissipation holes (203) in each slit air groove (201), the width of the heat dissipation hole (203) in each slit air groove (201) is Wm1, …, wmi, …, wmN, i is one natural number of 1 to N, wmi is less than or equal to Lmi, on one magnetic pole of the rotor core, along the Q axis, in the radial outward direction of the rotor core; and/or, 0.2.ltoreq.2 Wmi/Dr.ltoreq.0.8.

8. A self-starting synchronous reluctance machine rotor assembly according to any one of claims 4 to 7,

the projection of the heat dissipation hole (203) on any plane perpendicular to the axis of the rotor core is rectangular.

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

the end ring (301) is in a ring shape concentric with a rotating shaft hole (1021) of the rotor core, the radial width of the end ring (301) is W,wherein Dr is an outer diameter of the rotor core, and Dsft is a diameter of the rotation shaft hole (1021).

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 punching split body (10) in a die casting mold according to the target position of each punching split body 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, an inner cylinder body correspondingly matched with the inner circumferential wall of a rotating shaft hole (1021) and supporting bars correspondingly matched with the shape of each heat dissipation hole (203);

inserting each supporting bar into the forming position of each heat dissipation hole (203) 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, and after the injected electric conduction and 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 die.

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.