CN221509290U - Motor and air compressor - Google Patents

Abstract

The utility model provides a motor and an air compressor, wherein the motor comprises: a housing; the front flange and the rear end cover are respectively arranged at the opposite ends of the shell so as to jointly enclose an installation space; the rotor and the stator are sleeved outside the rotor, and the rotor and the stator are both positioned in the installation space; the motor comprises a motor and a shell, wherein a first shell cooling channel for circulating a first cooling medium and a second shell cooling channel for circulating a second cooling medium are arranged on the shell at intervals, so that the problem that the heat dissipation efficiency of a heat dissipation mode of a motor of the air compressor in the prior art is low is solved.

Description

Motor and air compressor

Technical Field

The utility model relates to the technical field of motors, and in particular to a motor and an air compressor.

Background Art

Screw air compressors are usually driven by electric motors. During operation, the higher the motor speed, torque density and power density, the higher the heat it generates. Therefore, the heat dissipation and cooling structure of the motor are essential settings for the reliable, stable and efficient operation of the motor.

At present, the cooling methods of motors can be divided into air cooling, water cooling and oil cooling. Oil-cooled motors have become the first choice for cooling solutions for high-performance motors due to their natural electrical insulation and high freedom of structural design. Their disadvantage is that oil is relatively expensive. Water-cooled motors are widely used because water has a large specific heat, can carry away heat well, has better heat transfer, cooling characteristics and economy than oil, basically does not increase noise, and water itself has no risks of explosion and toxicity and is easy to prepare. Their disadvantage is that water can conduct electricity, so a specific spiral flow channel needs to be set up. It cannot enter the interior of the motor like oil or be cooled by immersion.

At present, the heat dissipation method of the motor of the mainstream air compressor in the industry mostly adopts oil cooling. The motor casing is provided with an oil inlet and an oil outlet. The casing and the auxiliary system of the air compressor form a cooling circuit together. During operation, the cooled low-temperature lubricating oil flows into the oil inlet of the casing under the action of the pressure difference, and flows out from the oil outlet after passing through the heat dissipation channel in the casing to take away the heat generated by the motor. However, this heat dissipation method of dissipating the heat of the motor through only one heat dissipation channel has a low heat dissipation efficiency, which easily leads to the accumulation of heat surplus generated by the current during the operation of the motor, which is difficult to dissipate, resulting in excessive temperature rise of the motor, and even the phenomenon of motor burning.

Utility Model Content

The main purpose of the utility model is to provide a motor and an air compressor to solve the problem of low heat dissipation efficiency of the heat dissipation method of the motor of the air compressor in the prior art.

In order to achieve the above-mentioned purpose, according to one aspect of the utility model, a motor is provided, comprising: a casing; a front flange and a rear end cover, the front flange and the rear end cover are respectively arranged at opposite ends of the casing to jointly enclose an installation space; a rotor and a stator, the stator is arranged outside the rotor, and the rotor and the stator are both located in the installation space; wherein a first casing cooling channel for circulating a first cooling medium and a second casing cooling channel for circulating a second cooling medium are arranged on the casing at intervals.

Furthermore, the first casing cooling channel includes a first spiral flow channel arranged around the axis of the motor; the second casing cooling channel includes a second spiral flow channel arranged around the axis of the motor; wherein the first spiral flow channel is sleeved outside the second spiral flow channel.

Furthermore, a rear end cover cooling channel is provided on the rear end cover, the inlet of the rear end cover cooling channel is connected to the outlet of the external cooling device, and the outlet of the rear end cover cooling channel is connected to the installation space; a front flange cooling channel is provided on the front flange, the inlet of the front flange cooling channel is connected to the installation space, and the outlet of the front flange cooling channel is connected to the inlet of the external cooling device.

Further, the rotor includes a rotor shaft and a rotor core sleeved on the rotor shaft, the rotor shaft is a hollow circular shaft, and the two ends of the inner hole of the rotor shaft are respectively connected to the outlet of the rear end cover cooling channel and the inlet of the front flange cooling channel; and/or the stator includes a stator core, and a groove is arranged on the outer peripheral surface of the stator core, and the groove and the casing together form a stator cooling channel, and the two ends of the stator cooling channel are respectively connected to the outlet of the rear end cover cooling channel and the inlet of the front flange cooling channel.

Furthermore, the extending direction of the groove is parallel to the axis of the motor; and/or the number of the grooves is multiple, and the multiple grooves are arranged at intervals around the axis of the motor.

Furthermore, the rotor includes a bearing sleeved on one end of the rotor shaft near the rear end cover; the rear end cover includes an end cover body and a bearing mounting portion arranged on one side of the end cover body near the front flange; wherein a bearing mounting groove for mounting the bearing is provided on the bearing mounting portion, and the rear end cover cooling channel is provided on the end cover body and is connected with the bearing mounting groove so as to be connected with the first end of the inner hole of the rotor shaft through the bearing mounting groove.

Furthermore, the rear end cover cooling channel includes a first channel section and a second channel section that are connected to each other, the first channel section is a first strip-shaped channel section extending radially along the rotor shaft, and the second channel section is a first annular channel section arranged around the axis of the motor; wherein, one end of the first channel section is the rear end cover inlet, and the other end of the first channel section is connected to the bearing mounting groove to serve as the first rear end cover outlet; a second rear end cover outlet is arranged on one side of the second channel section close to the front flange.

Furthermore, the front flange includes a flange body and an annular flange arranged on one side of the flange body close to the rear end cover, and the front flange cooling channel is arranged on the flange body and connected to the inner hole of the annular flange so as to be connected to the second end of the inner hole of the rotor shaft through the inner hole of the annular flange.

Furthermore, the front flange cooling channel includes a third channel section and a fourth channel section that are connected to each other, the third channel section is a second strip channel section extending radially along the rotor shaft, and the fourth channel section is a second annular channel section arranged around the axis of the motor; wherein, one end of the third channel section is the front flange outlet, and the other end of the third channel section is connected to the inner hole of the annular flange to serve as the first front flange inlet; a second front flange inlet is arranged on one side of the fourth channel section close to the front flange.

According to another aspect of the utility model, an air compressor is provided, comprising the above-mentioned motor, and the air compressor also includes: a cooler; a first external cooling pipe and a first liquid pump arranged on the first external cooling pipe, the inlet and outlet of the first external cooling pipe are respectively connected to the outlet and inlet of the first casing cooling channel on the casing of the motor; a second external cooling pipe and a second liquid pump arranged on the second external cooling pipe, the inlet and outlet of the second external cooling pipe are respectively connected to the outlet and inlet of the second casing cooling channel on the casing of the motor; wherein the first external cooling pipe and the second external cooling pipe are arranged at intervals and both pass through the cooler.

Applying the technical solution of the utility model, the motor of the utility model comprises: a casing; a front flange and a rear end cover, the front flange and the rear end cover are respectively arranged at opposite ends of the casing to enclose an installation space together; a rotor and a stator, the stator is sleeved outside the rotor, and the rotor and the stator are both located in the installation space; wherein, the casing is provided with a first casing cooling channel for the circulation of a first cooling medium and a second casing cooling channel for the circulation of a second cooling medium. In this way, the motor of the utility model improves the heat dissipation efficiency of the motor by arranging the first casing cooling channel and the second casing cooling channel on the casing, effectively solves the problem of low heat dissipation efficiency of the heat dissipation method of the motor of the air compressor in the prior art, improves the power density of the motor, increases the current density of the motor, improves the working efficiency and operation stability of the motor, and thus improves the working efficiency of the air compressor with the motor of the utility model, achieving the purpose of energy saving.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

FIG1 shows a cross-sectional view of an embodiment of a motor according to the present utility model;

FIG2 is a schematic diagram showing the flow of the first portion of the coolant in the motor shown in FIG1 ;

FIG3 is a schematic diagram showing the flow of the second portion of the coolant in the motor shown in FIG1 ;

FIG4 shows a schematic structural diagram of the motor shown in FIG1 ;

FIG5 shows a bottom view of the front flange of the motor shown in FIG1 ;

FIG6 shows a top view of the rear end cover of the motor shown in FIG1 ;

FIG7 shows a front view of the rotor of the motor shown in FIG1 ;

FIG. 8 shows a front view of the stator of the motor shown in FIG. 1 .

The above drawings include the following reference numerals:

1. Casing; 11. First casing cooling channel; 111. First casing inlet; 112. First casing outlet; 12. Second casing cooling channel; 121. Second casing inlet; 122. Second casing outlet;

2. front flange; 21. front flange cooling channel; 211. third channel section; 212. fourth channel section; 22. front flange outlet; 23. front flange inlet; 231. first front flange inlet; 232. second front flange inlet; 201. flange body; 202. annular flange;

3. rear end cover; 31. rear end cover cooling channel; 311. first channel section; 312. second channel section; 32. rear end cover inlet; 33. rear end cover outlet; 331. first rear end cover outlet; 332. second rear end cover outlet; 301. end cover body; 302. bearing mounting portion; 303. bearing mounting groove;

4. rotor; 41. rotor shaft; 42. rotor core; 43. bearing;

5. stator; 51. stator core; 52. groove; 53. stator cooling channel;

6. Machine head.

DETAILED DESCRIPTION

It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

As shown in Figures 1 to 8, the utility model provides a motor, including: a casing 1; a front flange 2 and a rear end cover 3, the front flange 2 and the rear end cover 3 are respectively arranged at opposite ends of the casing 1 to jointly enclose an installation space; a rotor 4 and a stator 5, the stator 5 is sleeved outside the rotor 4, and the rotor 4 and the stator 5 are both located in the installation space; wherein, a first casing cooling channel 11 for circulating a first cooling medium and a second casing cooling channel 12 for circulating a second cooling medium are arranged on the casing 1 at intervals.

In this way, the motor of the utility model improves the heat dissipation efficiency of the motor by arranging the first casing cooling channel 11 and the second casing cooling channel 12 on the casing 1, effectively solving the problem of low heat dissipation efficiency of the heat dissipation method of the motor of the air compressor in the prior art, improving the power density of the motor, increasing the current density of the motor, improving the working efficiency and operation stability of the motor, thereby improving the working efficiency of the air compressor with the motor of the utility model and achieving the purpose of energy saving.

Specifically, the first cooling medium is water, and the second cooling medium is oil. The heat generated by the motor during operation is first dissipated through the oil in the second casing cooling channel 12, and then the heat absorbed by the oil in the second casing cooling channel 12 is transferred to the water in the first casing cooling channel 11 for secondary heat dissipation, effectively reducing the temperature rise of the stator of the motor, reducing the temperature resistance level required for the enameled wire, and reducing the production cost of the motor.

The structure of the oil-cooled motor in the prior art is mostly a single oil-cooling flow path with a large cross-sectional area. Under normal working conditions, the temperature inside and on the surface of the motor is above 100°C. The motor of the utility model can effectively reduce the temperature rise of the stator of the motor, and the enameled wire does not need to be made of high-grade raw materials, which effectively reduces copper loss and reduces the production cost of the motor.

Specifically, the casing 1 is a stretched casing with a simple structure and high reliability. It only needs to ensure the airtightness of the installation with the front flange 2 and the rear end cover 3 so that the cooling medium can enter and exit from the set flow path to effectively dissipate the heat of the motor; wherein, the first casing cooling channel 11 and the inlet and outlet are respectively the first casing inlet 111 and the first casing outlet 112, and the first casing inlet 111 and the first casing outlet 112 are arranged on the outer peripheral surface of the casing 1 at intervals along the axial direction of the motor; the second casing cooling channel 12 and the inlet and outlet are respectively the second casing inlet 121 and the second casing outlet 122, and the second casing inlet 121 and the second casing outlet 122 are arranged on the outer peripheral surface of the casing 1 at intervals along the axial direction of the motor.

As shown in FIG. 1 to FIG. 3 , the first casing cooling channel 11 includes a first spiral flow channel arranged around the axis of the motor; the second casing cooling channel 12 includes a second spiral flow channel arranged around the axis of the motor; wherein the first spiral flow channel is arranged outside the second spiral flow channel.

As shown in Figures 1 to 3, a rear end cover cooling channel 31 is provided on the rear end cover 3, the inlet of the rear end cover cooling channel 31 is connected to the outlet of the external cooling device, and the outlet of the rear end cover cooling channel 31 is connected to the installation space; a front flange cooling channel 21 is provided on the front flange 2, the inlet of the front flange cooling channel 21 is connected to the installation space, and the outlet of the front flange cooling channel 21 is connected to the inlet of the external cooling device.

As shown in Figures 1 to 3 and Figures 7 and 8, the rotor 4 includes a rotor shaft 41 and a rotor core 42 sleeved on the rotor shaft 41, the rotor shaft 41 is a hollow circular shaft, and the two ends of the inner hole of the rotor shaft 41 are respectively connected to the outlet of the rear cover cooling channel 31 and the inlet of the front flange cooling channel 21; and/or the stator 5 includes a stator core 51, and a groove 52 is provided on the outer peripheral surface of the stator core 51. The groove 52 and the casing 1 together form a stator cooling channel 53, and the two ends of the stator cooling channel 53 are respectively connected to the outlet of the rear cover cooling channel 31 and the inlet of the front flange cooling channel 21.

Specifically, a portion of the oil flowing out of the outlet of the rear end cover cooling channel 31 can pass through the inner hole of the rotor shaft 41 and reach the inlet of the front flange cooling channel 21, so as to cool the rotor shaft 41 during the operation of the motor, thereby taking away the heat generated by the rotor 4 during the operation, reducing the temperature rise of the rotor, and avoiding the risk of demagnetization of the rotor's magnetic steel due to overheating; another portion of the oil flowing out of the outlet of the rear end cover cooling channel 31 can pass through the stator cooling flow channel 53 and reach the inlet of the front flange cooling channel 21, so as to cool the stator core 51 during the operation of the motor, thereby taking away the heat generated by the stator 5 during the operation.

Preferably, the extending direction of the groove 52 is parallel to the axis of the motor; and/or there are multiple grooves 52, and the multiple grooves 52 are arranged at intervals around the axis of the motor.

As shown in Figures 1 to 3 and Figure 6, the rotor 4 includes a bearing 43 sleeved on one end of the rotor shaft 41 close to the rear end cover 3; the rear end cover 3 includes an end cover body 301 and a bearing mounting portion 302 arranged on one side of the end cover body 301 close to the front flange 2; wherein, a bearing mounting groove 303 for mounting the bearing 43 is provided on the bearing mounting portion 302, and the rear end cover cooling channel 31 is provided on the end cover body 301 and communicated with the bearing mounting groove 303, so as to communicate with the first end of the inner hole of the rotor shaft 41 through the bearing mounting groove 303.

Specifically, the inlet of the rear cover cooling channel 31 is the rear cover inlet 32 , the outlet of the rear cover cooling channel 31 is the rear cover outlet 33 , and the rear cover outlet 33 includes a first rear cover outlet 331 and a plurality of second rear cover outlets 332 .

As shown in Figures 1 to 3 and Figure 6, the rear end cover cooling channel 31 includes a first channel section 311 and a second channel section 312 that are connected to each other. The first channel section 311 is a first strip-shaped channel section extending radially along the rotor shaft 41, and the second channel section 312 is a first annular channel section arranged around the axis of the motor; wherein, one end of the first channel section 311 is the rear end cover inlet 32, and the other end of the first channel section 311 is connected to the bearing mounting groove 303 to serve as the first rear end cover outlet 331; a second rear end cover outlet 332 is arranged on one side of the second channel section 312 close to the front flange 2.

Specifically, a portion of the oil flowing out of the outlet of the rear end cover cooling channel 31 will pass through the bearing mounting groove 303 before reaching the inner hole of the rotor shaft 41, which can lubricate the bearing mounting groove 303, reduce the friction loss of the bearing 43, increase the life of the bearing 43, improve the working efficiency of the motor, and increase the life of the bearing.

As shown in Figures 1 to 3 and Figure 5, the front flange 2 includes a flange body 201 and an annular flange 202 arranged on one side of the flange body 201 close to the rear end cover 3, and the front flange cooling channel 21 is arranged on the flange body 201 and is connected to the inner hole of the annular flange 202 so as to be connected to the second end of the inner hole of the rotor shaft 41 through the inner hole of the annular flange 202.

Specifically, the outlet of the front flange cooling channel 21 is the front flange outlet 22 , the inlet of the front flange cooling channel 21 is the front flange inlet 23 , and the front flange inlet 23 includes a first front flange inlet 231 and a plurality of second front flange inlets 232 .

As shown in Figures 1 to 3 and Figure 5, the front flange cooling channel 21 includes a third channel section 211 and a fourth channel section 212 that are connected to each other. The third channel section 211 is a second strip channel section extending radially along the rotor shaft 41, and the fourth channel section 212 is a second annular channel section arranged around the axis of the motor; wherein, one end of the third channel section 211 is the front flange outlet 22, and the other end of the third channel section 211 is connected to the inner hole of the annular flange 202 to serve as the first front flange inlet 231; a second front flange inlet 232 is arranged on the side of the fourth channel section 212 close to the front flange 2.

The utility model also provides an air compressor, comprising the above-mentioned motor, and the air compressor also includes: a cooler; a first external cooling pipeline and a first liquid pump arranged on the first external cooling pipeline, the inlet and outlet of the first external cooling pipeline are respectively connected to the outlet and inlet of the first casing cooling channel 11 on the casing 1 of the motor; a second external cooling pipeline and a second liquid pump arranged on the second external cooling pipeline, the inlet and outlet of the second external cooling pipeline are respectively connected to the outlet and inlet of the second casing cooling channel 12 on the casing 1 of the motor; wherein the first external cooling pipeline and the second external cooling pipeline are arranged at intervals and both pass through the cooler.

In addition, the air compressor also includes a third external cooling pipe and a third liquid pump arranged on the cooling pipe. The third external cooling pipe passes through the cooler, and the inlet and outlet of the third external cooling pipe are respectively connected to the outlet of the rear end cover cooling channel 31 and the inlet of the front flange cooling channel 21.

Specifically, the air compressor includes a head 6 connected to a motor, and a cooler, a first liquid pump, a second liquid pump and a third liquid pump are all located in the head 6 .

From the above description, it can be seen that the above embodiments of the utility model achieve the following technical effects:

The motor of the utility model comprises: a housing 1; a front flange 2 and a rear end cover 3, the front flange 2 and the rear end cover 3 are respectively arranged at opposite ends of the housing 1 to enclose an installation space together; a rotor 4 and a stator 5, the stator 5 is sleeved outside the rotor 4, and the rotor 4 and the stator 5 are both located in the installation space; wherein, the housing 1 is provided with a first housing cooling channel 11 for the circulation of a first cooling medium and a second housing cooling channel 12 for the circulation of a second cooling medium. In this way, the motor of the utility model improves the heat dissipation efficiency of the motor by arranging the first housing cooling channel 11 and the second housing cooling channel 12 on the housing 1, effectively solves the problem of low heat dissipation efficiency of the heat dissipation method of the motor of the air compressor in the prior art, improves the power density of the motor, increases the current density of the motor, improves the working efficiency and operation stability of the motor, thereby improving the working efficiency of the air compressor having the motor of the utility model, and achieving the purpose of energy saving.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and/or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and/or combinations thereof.

Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims (10)

1. An electric machine, comprising:

A housing (1);

The front flange (2) and the rear end cover (3) are respectively arranged at two opposite ends of the shell (1) so as to jointly enclose an installation space;

The rotor (4) and the stator (5), the stator (5) is sleeved outside the rotor (4), and the rotor (4) and the stator (5) are both positioned in the installation space;

The shell (1) is provided with a first shell cooling channel (11) for circulating a first cooling medium and a second shell cooling channel (12) for circulating a second cooling medium at intervals.

2. An electric machine according to claim 1, characterized in that,

The first housing cooling channel (11) comprises a first spiral flow channel arranged around the axis of the motor;

The second housing cooling channel (12) comprises a second spiral flow channel arranged around the axis of the motor;

Wherein the first spiral flow passage is sleeved outside the second spiral flow passage.

3. An electric machine according to claim 1, characterized in that,

The rear end cover (3) is provided with a rear end cover cooling channel (31), an inlet of the rear end cover cooling channel (31) is communicated with an outlet of an external cooling device, and an outlet of the rear end cover cooling channel (31) is communicated with the installation space;

The front flange (2) is provided with a front flange cooling channel (21), an inlet of the front flange cooling channel (21) is communicated with the installation space, and an outlet of the front flange cooling channel (21) is communicated with an inlet of the external cooling device.

4. The motor of claim 3, wherein the motor is configured to control the motor,

The rotor (4) comprises a rotor shaft (41) and a rotor iron core (42) sleeved on the rotor shaft (41), the rotor shaft (41) is a hollow round shaft, and two ends of an inner hole of the rotor shaft (41) are respectively communicated with an outlet of the rear end cover cooling channel (31) and an inlet of the front flange cooling channel (21); and/or

The stator (5) comprises a stator core (51), a groove (52) is formed in the outer peripheral surface of the stator core (51), the groove (52) and the shell (1) jointly enclose a stator cooling flow channel (53), and two ends of the stator cooling flow channel (53) are respectively communicated with an outlet of the rear end cover cooling channel (31) and an inlet of the front flange cooling channel (21).

5. The motor of claim 4, wherein the motor is configured to control the motor to drive the motor,

-The direction of extension of the recess (52) is parallel to the axis of the motor; and/or

The number of the grooves (52) is a plurality, and the grooves (52) are arranged at intervals around the axis of the motor.

6. The motor of claim 4, wherein the motor is configured to control the motor to drive the motor,

The rotor (4) comprises a bearing (43) sleeved at one end of the rotor shaft (41) close to the rear end cover (3);

the rear end cover (3) comprises an end cover body (301) and a bearing mounting part (302) arranged on one side of the end cover body (301) close to the front flange (2);

Wherein, be provided with on the bearing installation portion (302) and be used for installing bearing mounting groove (303) of bearing (43), rear end cover cooling channel (31) set up on the end cover body (301) and with bearing mounting groove (303) intercommunication is in order to pass through bearing mounting groove (303) with the first end of the hole of rotor shaft (41).

7. The electric machine according to claim 6, characterized in that the rear end cap cooling channel (31) comprises a first channel section (311) and a second channel section (312) in communication, the first channel section (311) being a first strip-shaped channel section extending in the radial direction of the rotor shaft (41), the second channel section (312) being a first annular channel section arranged around the axis of the electric machine; wherein,

One end of the first channel section (311) is a rear end cover inlet (32), and the other end of the first channel section (311) is communicated with the bearing mounting groove (303) to serve as a first rear end cover outlet (331);

a second rear end cap outlet (332) is arranged on the side of the second channel section (312) close to the front flange (2).

8. The electric machine according to claim 4, characterized in that the front flange (2) comprises a flange body (201) and an annular flange (202) arranged at a side of the flange body (201) close to the rear end cap (3), the front flange cooling channel (21) being arranged on the flange body (201) and communicating with the inner bore of the annular flange (202) for communicating with the second end of the inner bore of the rotor shaft (41) through the inner bore of the annular flange (202).

9. The electric machine according to claim 8, characterized in that the front flange cooling channel (21) comprises a third channel section (211) and a fourth channel section (212) in communication, the third channel section (211) being a second strip-shaped channel section extending in the radial direction of the rotor shaft (41), the fourth channel section (212) being a second annular channel section arranged around the axis of the electric machine; wherein,

One end of the third channel section (211) is a front flange outlet (22), and the other end of the third channel section (211) is communicated with an inner hole of the annular flange (202) to serve as a first front flange inlet (231);

A second front flange inlet (232) is arranged on the side, close to the front flange (2), of the fourth channel section (212).

10. An air compressor comprising the electric machine of any one of claims 1 to 9, the air compressor further comprising:

a cooler;

The motor comprises a first external cooling pipeline and a first liquid pump arranged on the first external cooling pipeline, wherein an inlet and an outlet of the first external cooling pipeline are respectively connected with an outlet and an inlet of a first shell cooling channel (11) on a shell (1) of the motor;

A second external cooling pipeline and a second liquid pump arranged on the second external cooling pipeline, wherein the inlet and the outlet of the second external cooling pipeline are respectively connected with the outlet and the inlet of a second shell cooling channel (12) on a shell (1) of the motor;

Wherein the first and second external cooling pipes are disposed at intervals and both pass through the cooler.