CN221227233U - Rotor assembly, motor and vehicle - Google Patents

Abstract

The application discloses a rotor assembly, a motor and a vehicle, and solves the technical problem that the motor arrangement space utilization rate is low in the prior art. The rotor assembly comprises a rotating shaft, an iron core assembly and a heat radiating piece, wherein the rotating shaft is connected with a limiting ring; the iron core component is sleeved outside the rotating shaft and comprises a rotor iron core and a squirrel cage end ring positioned at one axial end of the rotor iron core, and the squirrel cage end ring is sleeved outside the limiting ring in a clearance mode; the heat dissipation part comprises a mounting part and blades, the mounting part is provided with a stepped hole for the rotating shaft to extend in, and the end part of the mounting part, which is close to the large hole, is connected with the blades; the squirrel cage end ring is sleeved outside the mounting piece, the step surface of the mounting piece is abutted with the limiting ring, and the limiting ring is positioned in the large hole of the step hole. The rotor assembly is compact in structure and high in space utilization rate.

Description

Rotor assembly, motor and vehicle

Technical Field

The application belongs to the technical field of rotors, and particularly relates to a rotor assembly, a motor and a vehicle.

Background

The motor is a device for converting electric energy into mechanical energy, and mainly comprises a stator, a rotor, a shell, an end cover and the like. In motor use, the motor can produce a large amount of heat, and after the heat reaches certain degree, the motor can not be used, otherwise insulation breakdown can occur, and the motor burns out.

In the prior art, a cooling fan is arranged on a rotating shaft of a motor to stir a motor cavity for cooling, wherein the cooling fan, a rotor end ring and a rotor core are sequentially arranged along the axial direction, and the arrangement structure occupies large space and has low space utilization rate.

Disclosure of Invention

The application provides a rotor assembly, a motor and a vehicle, and aims to solve the technical problem that the existing motor is low in space utilization rate in heat dissipation structure arrangement.

In a first aspect of the present application, there is provided a rotor assembly comprising:

The rotating shaft is connected with a limiting ring;

The iron core assembly is sleeved outside the rotating shaft and comprises a rotor iron core and a squirrel cage end ring positioned at one axial end of the rotor iron core, and the squirrel cage end ring is in clearance sleeve outside the limiting ring;

The heat dissipation part comprises a mounting part and blades, the mounting part is provided with a stepped hole for the rotating shaft to extend in, and the end part of the mounting part, which is close to the large hole, is connected with the blades;

The squirrel cage end ring is sleeved outside the mounting piece, the step surface of the mounting piece is abutted to the limiting ring, and the limiting ring is positioned in the large hole of the step hole.

In some embodiments, the mounting member extends radially to an end face of the squirrel cage end ring proximate to the end of the large bore, and a portion of the end of the mounting member extending to the end face of the squirrel cage end ring is disposed in a gap with the end face of the squirrel cage end ring.

In some embodiments, the squirrel cage end ring is provided with a first lightening hole extending along the rotation axis, an outer diameter of an end portion of the mounting is smaller than an outer diameter of the squirrel cage end ring, and a projection of the first lightening hole along the rotation axis is located outside the mounting.

In some embodiments, the two heat dissipation parts, the limiting rings and the squirrel cage end rings are respectively arranged, the two heat dissipation parts are respectively positioned at two sides of the axial direction of the rotor core, and the shaft section where the small holes of the two heat dissipation parts are positioned is positioned between the two limiting rings.

In some embodiments, one of the two limiting rings is a pressing ring, and the other is a shaft shoulder, and the shaft shoulder and the rotating shaft are of an integrated structure.

In some embodiments, the aperture of the mounting member is in clearance fit with the shaft.

In some embodiments, a plurality of the blades are connected to the end of the mounting member, and the plurality of blades are spaced around the axis of the rotating shaft.

In some embodiments, the rotor core is provided with a plurality of second lightening holes penetrating through the rotor core along the axial direction of the rotating shaft, the plurality of second lightening holes are arranged at intervals, and the projection of the squirrel cage end ring along the axial direction of the rotating shaft falls outside the second lightening holes.

In a second aspect of the application, there is provided an electric machine comprising the rotor assembly of the first aspect.

In a third aspect of the application, there is provided a vehicle comprising the electric machine of the second aspect.

The rotor assembly comprises a rotating shaft, an iron core assembly and a heat radiating piece, wherein the rotating shaft is connected with a limiting ring; the iron core component is sleeved outside the rotating shaft and comprises a rotor iron core and a squirrel cage end ring positioned at one axial end of the rotor iron core, and the squirrel cage end ring is sleeved outside the limiting ring in a clearance mode; the heat dissipation part comprises a mounting part and blades, the mounting part is provided with a stepped hole for the rotating shaft to extend in, and the end part of the mounting part, which is close to the large hole, is connected with the blades; the squirrel cage end ring is sleeved outside the mounting piece, the step surface of the mounting piece is abutted with the limiting ring, and the limiting ring is positioned in the large hole of the step hole.

The pivot is connected in the spacing ring, and the setting of spacing ring can provide axial spacing for iron core subassembly. The iron core component rotates under the action of a magnetic field generated after the stator component is electrified, so that electric energy is converted into kinetic energy.

The squirrel cage end ring clearance sleeve is arranged outside the limiting ring to provide the installation space of the heat dissipation part and improve the space utilization rate. The heat dissipation piece is sleeved outside the rotating shaft, so that the heat dissipation piece can rotate along with the rotating shaft, when the rotor assembly is applied to a non-oil-cooled motor, the blades on the heat dissipation piece can stir air inside the motor cavity in the rotation process of the mounting piece, so that air flow circularly flows, heat inside the rotor assembly is conducted out more fully, the temperature of a rotor core is reduced to a certain extent, and the reliability and the service life of motor operation are improved. When the rotor assembly is applied to an oil-cooled motor, the blades can assist the rotor to stir oil in the rotating process along with the rotating shaft, so that cooling oil particles are more dispersed, the flow velocity of the cooling oil particles is improved through beating, the stator winding of the motor is fully contacted with the cooling oil, the temperature of the stator winding is effectively reduced, and the cooling efficiency is improved.

The squirrel cage end ring sleeve is arranged outside the mounting piece, namely, the shaft section where the large hole of the stepped hole is located is positioned between the limiting ring and the squirrel cage end ring, so that the gap between the limiting ring and the squirrel cage end ring is fully utilized, and the space utilization rate is improved. The small hole of the stepped hole is positioned at the axial section between the limiting ring and the rotor core, and the stepped surface of the mounting piece is abutted with the limiting ring so as to axially limit the heat dissipation piece, thereby axially limiting the rotor core. The limiting ring is positioned in the large hole of the stepped hole, namely the large hole of the stepped hole is used as an avoidance hole for accommodating the limiting ring, so that the axial length dimension is shortened, and the space utilization rate is further improved.

According to the application, the radiating piece is arranged on the rotor assembly, so that the radiating efficiency of the rotor is improved, and the running reliability and service life of the motor are improved. And the limiting ring is arranged, so that the axial positioning of the radiating piece and the rotor core is realized. Compared with the heat dissipation piece, the squirrel cage end ring and the rotor core are sequentially arranged, the squirrel cage end ring is sleeved outside the limiting ring in a clearance mode, the gap between the squirrel cage end ring and the limiting ring is used for accommodating the shaft section of the large hole of the stepped hole of the heat dissipation piece, the axial size of the rotor assembly is reduced, the rotor assembly is compact in structure, and the space utilization rate is high.

Drawings

FIG. 1 illustrates a schematic structural diagram of a rotor assembly in one or more embodiments of the application.

FIG. 2 illustrates a schematic view of another angle of the rotor assembly of FIG. 1.

Fig. 3 shows an exploded view of the rotor assembly of fig. 1.

Fig. 4 shows a cross-sectional view of the rotor assembly of fig. 1.

Fig. 5 shows a schematic structural view of a heat sink in the rotor assembly of fig. 1.

Fig. 6 shows a schematic B-B structure of the heat sink of fig. 5.

Fig. 7 shows a back view of the heat sink of fig. 5.

Fig. 8 shows a schematic structural view of another heat sink.

Fig. 9 shows a schematic structural view of yet another heat sink.

Fig. 10 shows an exploded view of a motor in one or more embodiments of the application.

Reference numerals illustrate:

100-rotor assembly, 110-rotating shaft, 111-shaft shoulder, 120-iron core assembly, 121-rotor iron core, 121 a-second lightening hole, 122-squirrel cage end ring, 130-heat dissipation piece, 131-mounting piece, 131 a-mounting section, 131 b-connecting section, 131 c-limit section, 131 d-big hole, 131 f-small hole, 131 g-step surface, 132-blade, 140-limit ring and 141-clamping ring.

200-Stator assembly, 300-motor housing, 400-end cap, 500-reducer housing, 600-bearing.

Detailed Description

In order to make the present application more clearly understood by those skilled in the art, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. 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.

According to the embodiment of the first aspect of the application, the rotor assembly is provided, so that the heat dissipation efficiency of the motor is improved, the rotor assembly is compact in structure and high in space utilization rate.

Referring to fig. 1 to 4, a rotor assembly 100 provided by an embodiment of the present application includes a rotating shaft 110, an iron core assembly 120, and a heat dissipation member 130, wherein the rotating shaft 110 is connected with a limiting ring 140; the iron core assembly 120 is sleeved outside the rotating shaft 110, the iron core assembly 120 comprises a rotor iron core 121 and a squirrel cage end ring 122 positioned at one axial end of the rotor iron core 121, and the squirrel cage end ring 122 is sleeved outside the limiting ring 140 in a clearance manner; the heat dissipation member 130 comprises a mounting member 131 and a blade 132, wherein the mounting member 131 is provided with a stepped hole for the rotating shaft 110 to extend into, and the end part of the mounting member 131 close to the large hole 131d is connected with the blade 132; the squirrel cage end ring 122 is sleeved outside the mounting piece 131, the stepped surface 131g of the mounting piece 131 is abutted with the limiting ring 140, and the limiting ring 140 is positioned in the large hole 131d of the stepped hole.

The rotating shaft 110 is a power transmission structure, and the rotor rotates to drive the rotating shaft 110 to rotate, so that power is transmitted to wheels to drive the vehicle to run. The rotating shaft 110 is connected to the limiting ring 140, i.e. the limiting ring 140 is sleeved outside the rotating shaft 110, and the limiting ring 140 can provide axial limiting for the iron core assembly 120.

The core assembly 120 rotates under the magnetic field generated after the stator assembly is energized, thereby converting electrical energy into kinetic energy. The iron core assembly 120 is sleeved outside the rotating shaft 110, and two ends of the rotating shaft 110 extend out of the iron core assembly 120, so that kinetic energy is transferred to the rotating shaft 110. The squirrel-cage end ring 122 is sleeved outside the limiting ring 140 in a clearance manner, so that the installation space of the heat dissipation piece 130 is provided, and the space utilization rate is improved.

The heat dissipation member 130 is sleeved outside the rotating shaft 110, so that the heat dissipation member 130 can rotate along with the rotating shaft 110, when the rotor assembly 100 is applied to a non-oil-cooled motor, the blades 132 on the heat dissipation member 130 can stir air in the motor cavity in the rotating process of the mounting member 131, so that air flow circularly flows, heat in the rotor assembly 100 is more fully conducted, the temperature of the rotor core 121 is reduced to a certain extent, and the reliability and the service life of the motor are improved. When the rotor assembly 100 is applied to an oil-cooled motor, the blades 132 can assist the rotor in stirring oil in the process of rotating along with the rotating shaft 110, so that cooling oil particles are more dispersed, and the flow velocity of the cooling oil particles is improved by beating, so that the stator winding of the motor is fully contacted with the cooling oil, the temperature of the stator winding is effectively reduced, and the cooling efficiency is improved.

The squirrel-cage end ring 122 is sleeved outside the mounting piece 131, namely, the shaft section of the large hole 131d of the stepped hole is positioned between the limiting ring 140 and the squirrel-cage end ring 122, so that the gap between the limiting ring 140 and the squirrel-cage end ring 122 is fully utilized, and the space utilization rate is improved. The shaft section of the small hole 131f of the stepped hole is positioned between the limiting ring 140 and the rotor core 121, and the stepped surface 131g of the mounting piece 131 is abutted against the limiting ring 140 so as to axially limit the heat dissipation piece 130, thereby axially limiting the rotor core 121. The limiting ring 140 is located in the large hole 131d of the stepped hole, namely, the large hole 131d of the stepped hole is used as an avoidance hole and used for accommodating the limiting ring 140, so that the axial length dimension is shortened, and the space utilization rate is further improved.

The present application provides the heat sink 130 on the rotor assembly 100 to improve the heat dissipation efficiency of the rotor, thereby improving the reliability and lifetime of the motor operation. On the basis of arranging the heat dissipation piece 130, the squirrel cage end ring 122 is sleeved outside the limit ring 140 in a clearance mode, the gap between the squirrel cage end ring 122 and the limit ring 140 is used for accommodating the shaft section where the large hole 131d of the stepped hole of the heat dissipation piece 130 is located, the axial size of the rotor assembly 100 is reduced, the rotor assembly 100 is compact in structure, and the space utilization rate is high.

In some embodiments, referring to fig. 4 and 6, the end of the mounting member 131 close to the large hole 131d extends radially to the end face of the cage end ring 122, so as to increase the size of the end face of the mounting member 131 close to the large hole 131d, so that the blades 132 connected to the end face have a larger arrangement space, and the larger the size of the blades 132, the better the effect of stirring the air flow or cooling oil. That is, referring to fig. 6, the heat dissipation member 130 includes a mounting section 131a, a connecting section 131b and a limiting section 131c sequentially arranged along the axial direction, the mounting section 131a is connected to the blade 132, the mounting section 131a is located at the axial outer side of the squirrel-cage end ring 122, the connecting section 131b is an axial section where the large hole 131d of the stepped hole is located, and is located between the squirrel-cage end ring 122 and the limiting ring 140, the limiting section 131c is an axial section where the small hole 131f of the stepped hole is located, and is located between the limiting ring 140 and the rotor core 121, and the outer diameter of the mounting section 131a is larger than the outer diameter of the connecting section 131 b.

Since the stop collar 140 has axially stopped the mounting member 131 and the rotor core 121, in some embodiments, referring to fig. 4, the portion of the end portion of the mounting member 131 extending to the end face of the squirrel-cage end ring 122 is disposed in a gap with the end face of the squirrel-cage end ring 122, that is, the mounting section 131a is disposed in a gap with the end face of the squirrel-cage end ring 122, so as to avoid the over-positioning problem caused by the double stop surfaces.

In certain embodiments, the cage end ring 122 is provided with a first lightening hole (not shown) extending along the rotation shaft 110 to lighten the rotor core 121, and the outer diameter of the end of the mounting member 131 is smaller than the outer diameter of the cage end ring 122, i.e., the outer diameter of the mounting section 131a is smaller than the outer diameter of the cage end ring 122, and the projection of the first lightening hole along the rotation shaft 110 is located outside the mounting member 131. In some embodiments, the plurality of first lightening holes are arranged at intervals, the first lightening holes can realize the effect of lightening, and meanwhile, the arrangement of the first lightening holes can also ensure the dynamic balance of the rotor assembly 100. The projection of the first lightening hole along the rotating shaft 110 is located outside the mounting member 131, so as to facilitate processing of the first lightening hole, and meanwhile, the heat dissipation member 130 can agitate the air flow in the first lightening hole during the rotation process, so as to dissipate heat better.

In some embodiments, referring to fig. 1 to 4, two heat dissipation members 130, two limiting rings 140 and two squirrel-cage end rings 122 are respectively disposed on two sides of the rotor core 121 in the axial direction, the small holes 131f of the two heat dissipation members 130 are located between the two limiting rings 140, that is, the first limiting ring 140, the first heat dissipation member 130, the rotor core 121, the second heat dissipation member 130 and the second limiting ring 140 are sequentially disposed along the axial direction of the rotating shaft 110, two squirrel-cage end rings 122 are respectively disposed on two ends of the rotor core 121 in the axial direction, the two squirrel-cage end rings 122 are respectively sleeved outside the two limiting rings 140 in a gap manner, the two squirrel-cage end rings 122 are respectively sleeved outside the large holes 131d of the two heat dissipation members 130, and the end parts of the two heat dissipation members 130 are respectively located outside the two squirrel-cage end rings 122.

In some embodiments, referring to fig. 4, one of the two limiting rings 140 is a pressing ring 141, and the other is a shoulder 111, and the shoulder 111 and the rotating shaft 110 are integrally formed. The shaft shoulder 111 is arranged on the rotating shaft 110 to axially position the heat dissipation element 130, the rotor core 121 and the pressing ring 141, the pressing ring 141 is connected to the rotating shaft 110, and the pressing ring 141 and the shaft shoulder 111 are combined to axially limit the rotor core 121 and the two heat dissipation elements 130 which are positioned between the pressing ring 141 and the shaft shoulder 111. In some embodiments, the clamping ring 141 is an interference fit with the spindle 110.

In some embodiments, the small hole 131f of the mounting member 131 is in clearance fit with the rotating shaft 110, so that the heat dissipation member 130 is conveniently sleeved outside the rotating shaft 110, and the mounting is convenient. In some embodiments, the shaft 110 is keyed to the rotor core 121 to circumferentially constrain the rotor core 121.

In some embodiments, referring to fig. 7 to 9, a plurality of blades 132 are connected to an end of the mounting member 131, and the plurality of blades 132 are spaced around an axis of the rotating shaft 110. The blades 132 may be provided with four, five, eight, ten, etc., and the number of the blades 132 is not limited; in some embodiments, the blades 132 may extend radially, and in other embodiments, the blades 132 may be radially angled from the axis of rotation 110 by between 0 and 90. In certain embodiments, the vane 132 is arcuate, or the vane 132 includes arcuate and straight sections that are connected.

In certain embodiments, the outer diameter of the end of the mounting member 131 proximate the large aperture 131d is the same as the outer diameter of the squirrel cage end ring 122, and in certain embodiments, referring to FIG. 4, the outer diameter of the end of the mounting member 131 proximate the large aperture 131d is less than the outer diameter of the squirrel cage end ring 122.

In some embodiments, referring to fig. 3 and 4, the rotor core 121 is provided with a plurality of second lightening holes 121a penetrating along the axial direction of the rotating shaft 110, the plurality of second lightening holes 121a are spaced apart, and the projection of the squirrel cage end ring 122 along the axial direction of the rotating shaft 110 falls outside the second lightening holes 121 a. The squirrel cage is obtained by casting the rotor core 121, and if the projection of the squirrel cage end ring 122 along the axial direction of the rotating shaft 110 falls into the second lightening holes 121a, liquid enters into the second lightening holes 121a during casting.

In some embodiments, referring to fig. 4, the second lightening hole 121a is projected along the axial direction of the rotating shaft 110 to fall in the end face of the heat dissipation member 130 close to the small hole 131f, so as to ensure that the small end face of the heat dissipation member 130 has a larger abutting area with the rotor core 121, and improve stability.

In some embodiments, the iron core assembly 120 further includes a plurality of cage bars, the rotor core 121 is provided with a mounting hole into which the rotating shaft 110 extends and a plurality of guide holes extending along the axial direction of the rotating shaft 110, the guide holes are far away from the mounting hole and are arranged along the circumferential direction of the mounting hole with respect to the second lightening hole 121a, the cage bars are arranged in the guide holes in a one-to-one correspondence manner, and two ends of the cage bars are respectively connected to the two cage end rings 122. When the rotor assembly 100 works, the hole wall of the guide hole limits the squirrel cage guide bars, so that the connection stability of the squirrel cage and the rotor core 121 is ensured.

In some embodiments, the rotor core 121 may be a non-oriented silicon steel core, and the cage bars and the two cage end rings 122 form a cage, which is an aluminum cage.

In a second aspect of the present application, an embodiment of the present application provides an electric machine comprising the rotor assembly 100 of the first aspect.

Referring to fig. 10, the motor provided by the embodiment of the application further includes a stator assembly 200 and a housing 300, wherein the stator assembly 200 is sleeved outside the rotor assembly 100, and the stator assembly 200 and the rotor assembly 100 are both positioned in the housing 300.

In some embodiments, a cooling flow passage through which a cooling medium flows and an inlet and an outlet communicating with the cooling flow passage are provided in the housing 300. In certain embodiments, the cooling flow channels are disposed helically about the axis of the shaft 110, and in certain embodiments, the cooling flow channels are disposed serpentine over the cylindrical surface of the housing 300. The cooling liquid enters the cooling flow channel from the inlet and is discharged from the outlet so as to cool the motor.

In some embodiments, the motor further includes an end cover 400, the end cover 400 is connected to one axial end of the housing 300, the end cover 400 is provided with a mounting hole into which the rotating shaft 110 extends, two ends of the rotating shaft 110 are connected with bearings 600, one bearing 600 is mounted in the mounting hole of the end cover 400, the other bearing 600 is mounted in the housing 500 of the reducer, and the heat dissipation element 130 is disposed in a gap with the corresponding bearing 600.

In a third aspect of the application, an embodiment of a vehicle is provided comprising the motor of the second aspect.

The vehicle provided by the embodiment of the application further comprises a speed reducer, and the rotating shaft 110 is in transmission connection with a speed reducing shaft of the speed reducer.

The rotor assembly 100, the motor and the vehicle provided by the application have at least the following advantages:

(1) The heat sink 130 has a stepped structure, and the concave portion, i.e. the large hole 131d, accommodates the shaft shoulder 111 and the pressing ring 141, so that the axial dimension of the rotor assembly 100 is shortened, the gap between the heat sink 130 and the bearing 600 is ensured, and the structure is compact.

(2) The end part of the heat dissipation piece 130 extends to the axial outer side of the squirrel cage end ring 122 along the radial direction, so that a larger arrangement space is provided for the blades 132, the air flow in the motor cavity is fully disturbed in the rotating process of the non-oil-cooled asynchronous rotor, and the heat in the rotor core 121 is effectively brought out, so that the heat dissipation of the rotor assembly 100 is improved, the heat damage of the motor rotor is reduced, and the reliability of the motor is improved; the oil-cooled asynchronous rotor can fully strike cooling oil in the rotation process, so that the stator winding is fully contacted with the cooling oil, and the temperature of the stator winding is effectively reduced.

(3) The projection of the first lightening holes of the squirrel cage end ring 122 along the axial direction is positioned outside the heat dissipation piece 130, so that the first lightening holes can be conveniently and smoothly processed, and the air flow in the first lightening holes can be stirred in the rotation process of the heat dissipation piece 130, so that heat dissipation is better.

(4) The second lightening holes 121a of the rotor core 121 are located in the squirrel cage end ring 122, so that the squirrel cage end ring 122 is matched with the stepped structure of the heat dissipation member 130, the axial space utilization rate is improved, and smooth casting of the core assembly 120 is ensured.

In the present application, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" indicate orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the present application, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

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

Claims (10)

1. A rotor assembly, comprising:

The rotating shaft is connected with a limiting ring;

The iron core assembly is sleeved outside the rotating shaft and comprises a rotor iron core and a squirrel cage end ring positioned at one axial end of the rotor iron core, and the squirrel cage end ring is sleeved outside the limiting ring;

The heat dissipation part comprises a mounting part and blades, wherein the mounting part is provided with a stepped hole for the rotating shaft to extend in, and the end part of the mounting part, which is close to the large hole of the stepped hole, is connected with the blades;

The squirrel cage end ring is sleeved outside the mounting piece, the step surface of the mounting piece is abutted to the limiting ring, and the limiting ring is positioned in the large hole of the step hole.

2. The rotor assembly of claim 1, wherein the mounting member extends radially to an end face of the squirrel cage end ring proximate to the end of the large bore, the portion of the mounting member extending to the end face of the squirrel cage end ring being disposed in clearance with the end face of the squirrel cage end ring.

3. The rotor assembly of claim 2, wherein the squirrel cage end ring is provided with a first lightening hole extending along the shaft, an outer diameter of an end of the mounting member is smaller than an outer diameter of the squirrel cage end ring, and a projection of the first lightening hole along the shaft is located outside the mounting member.

4. A rotor assembly according to any one of claims 1 to 3, wherein two heat dissipation members, two limiting rings and two squirrel cage end rings are respectively arranged, the two heat dissipation members are respectively arranged on two axial sides of the rotor core, and the shaft section where small holes of the two heat dissipation members are arranged is arranged between the two limiting rings.

5. The rotor assembly of claim 4, wherein one of the two stop collars is a press ring and the other is a shoulder, the shoulder being of unitary construction with the shaft.

6. A rotor assembly according to any one of claims 1 to 3, wherein the aperture of the mounting member is in clearance fit with the shaft.

7. A rotor assembly according to any one of claims 1 to 3, wherein a plurality of said blades are attached to an end of said mounting member, said plurality of blades being spaced about an axis provided to said shaft.

8. A rotor assembly according to any one of claims 1 to 3, wherein the rotor core is provided with a plurality of second lightening holes penetrating through the shaft in the axial direction of the shaft, the plurality of second lightening holes being arranged at intervals, and the projection of the squirrel cage end ring in the axial direction of the shaft falling outside the second lightening holes.

9. An electric machine comprising a rotor assembly as claimed in any one of claims 1 to 8.

10. A vehicle comprising the electric machine of claim 9.