Radial ventilation cooling structure for motor

A radial ventilation cooling structure for a motor includes at least three core sections, a ventilation channel steel is provided between every two adjacent core sections, and a ventilation channel is formed between the ventilation channel steel and the every two adjacent core sections, and impedances of the multiple ventilation channels are gradually increased in a direction from two ends of the motor to a center of the motor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the national phase of International Application No. PCT/CN2015/094824, titled “RADIAL VENTILATION COOLING STRUCTURE FOR MOTOR”, filed on Nov. 17, 2015, which claims the benefit of priority to Chinese Patent Application No. 201510337278.2 titled “RADIAL VENTILATION COOLING STRUCTURE FOR MOTOR”, filed with the Chinese State Intellectual Property Office on Jun. 17, 2015, the entire disclosures of which are incorporated herein by reference.

FIELD

This application relates to the field of motor technology, and particularly to a radial ventilation cooling structure for a motor.

BACKGROUND

When a motor is operating, coils, cores and other components may have energy loss, this part of loss is eventually dissipated in the form of heat energy. Radial ventilation cooling is one of commonly used cooling manners for the motor. This cooling manner can increase the heat dissipation area and improve the power density of the generator, thus it has been widely used.

As shown inFIG. 1, the core of the motor is divided into multiple core sections11, a ventilation channel steel12is provided between adjacent core sections11in a radial direction of the motor. The ventilation channel steel12has a supporting effect to the core sections11, and also divides the space between adjacent core sections11into a ventilation channel13. The motor has a recirculation ventilation path in which a cold air enters an air gap14from an end of a winding (not shown) and passes through the ventilation channel13(for example, branch ventilation channels1to8in the Figure), and reaches a cavity between two core brackets15, and finally the hot air in the cavity is drawn through a pipeline to a heat exchanger outside the motor and converted into a cold air by the heat exchanger, and then the cold air enters the inside of the motor. As shown inFIG. 2, the ventilation channel steel12in the conventional radial ventilation cooling structure for the motor is a bar-shaped ventilation channel steel having a rectangular cross section, and the height of the ventilation channel13in an axial direction of the motor, that is the height h of the ventilation channel steel12in the axial direction of the motor (as shown inFIGS. 1 and 2), is equal to the distance between adjacent core sections11in the axial direction of the motor.

In the process of implementing the above ventilation cooling, the inventors have found that there are at least the following issues in the conventional technology. After the airflow enters the air gap, the velocity of the airflow is continuously reduced due to the bypassing effect, a local drag and a frictional drag of the ventilation channels and the like, thus the static pressure is increasingly greater and the dynamic pressure is increasingly smaller from an inlet of the air gap to a middle position of the air gap. However, since the multiple ventilation channel steels has the same structure and the multiple core sections has the same structure, the multiple ventilation channels have the same impedance, thus the quantity of airflow flowing through the multiple ventilation channels are increasingly larger. The heat generated by the internal heat source (coils, cores, and etc.) of the motor is distributed uniformly in the axial direction of the motor, while the airflow flowing through the multiple ventilation channels is distribute non-uniformly, thus the distribution of the temperature of the coils and the multiple core sections in the axial direction of the motor is not uniform, and the temperature from the inlet of the air gap to the middle position of the air gap is increasingly lower. The distribution of the temperature of the coils and the multiple core sections in the axial direction of the motor is not uniform, and the maximum temperature value is great, which is apt to cause a too high local temperature rising phenomenon, resulting in a shutdown of the motor, and is also apt to cause the core bracket to be thermally deformed, and therefore affecting the normal operation of the motor.

SUMMARY

A radial ventilation cooling structure for a motor is provided according to embodiments of the present application, which can improve the uniformity of the quantities of the airflow flowing through multiple ventilation channels, and in turn improve the uniformity of temperature distribution of coils and multiple core sections in an axial direction of the motor. Therefore, the maximum temperature value can be reduced without changing the total flowing quantity of the airflow, thus effectively avoiding the shutdown of the motor caused by an excessive local temperature rise, reducing the thermal deformation of a core bracket, and ensuring the normal operation of the motor.

In order to achieve the above objects, a radial ventilation cooling structure for a motor is provided according to the present application, which includes at least three core to sections, a ventilation channel steel is provided between every two adjacent core sections, and a ventilation channel is formed between the ventilation channel steel and the every two adjacent core sections, and impedances of the multiple ventilation channels are gradually increased in a direction from two ends of the motor to a center of the motor.

In the radial ventilation cooling structure for the motor according to the present application, the impedances of the multiple ventilation channels are gradually increased in the direction from the two ends of the motor to the center of the motor, thus improving the uniformity of the quantities of the airflow flowing through the multiple ventilation channels, and in turn improving the uniformity of the temperature distribution of the coils and the multiple core sections in the axial direction of the motor. Therefore, the maximum temperature value is reduced without changing the total quantity of the airflow, which effectively avoids the shutdown of the motor caused by the excessive local temperature rise and at the same time reduces the thermal deformation of the core bracket, thereby ensuring the normal operation of the motor.

In the drawings:

DETAILED DESCRIPTION

A radial ventilation cooling structure for a motor according to embodiments of the present application is described in detail hereinafter with reference to the accompanying drawings.

First Embodiment

Referring to a conventional radial ventilation cooling structure for a motor shown inFIG. 1, the radial ventilation cooling structure for the motor according to this embodiment of the present application also includes at least three core sections11, a ventilation channel steel12is provided between every two adjacent core sections11, and a ventilation channel13is formed between the ventilation channel steel12and the every two adjacent core sections11. However, unlike the conventional radial ventilation cooling structure for the motor, in the radial ventilation cooling structure for the motor according to this embodiment of the present application, multiple ventilation channel steels12and/or multiple core sections11have different structures, which allows the impedances R of the multiple ventilation channels13to gradually increase in a direction from two ends of the motor to the center of the motor.

The impedance R of the ventilation channel13is a drag (including a local drag and a frictional drag) applied by the ventilation channel13to the airflow. The ventilation channels13in the radial ventilation cooling structure for the motor according to this embodiment may be equivalent to pipelines connected in parallel in fluid mechanics. As shown inFIG. 3(only a half of the symmetrical structure of the motor is shown), the node a is an air inlet of an air gap14, and the nodes a1, a2, . . . , a8are respectively air inlets of branch ventilation channels1,2, . . . ,8, and the node h is an air outlet of the branch ventilation channels1,2, . . . ,8. After the airflow enters the air gap14, the velocity of the airflow is increasingly smaller due to the bypassing effect, the local drag and the frictional drag of the ventilation channels13and other reasons, thus the static pressures U1, U2, . . . , U8of the airflow at the nodes a1, a2, . . . , a8is increasingly greater and the dynamic pressures of the airflow at the nodes a1, a2, . . . , a8is increasingly smaller from the inlet of the air gap14to the middle position of the air gap14, that is, in the direction from two ends of the motor to the center of the motor. Assuming that the static pressure of the airflow at the node b (that is, the outlet of the ventilation channel13) is U0, according to the flow distribution law of the parallel pipelines in fluid mechanics:

It can be seen that the impedances R of the multiple ventilation channels13are gradually increased in the direction from the two ends of the motor to the center of the motor, that is, the impedances R1, R2, . . . , R8of the branch ventilation channels1,2, . . . ,8are gradually increased (the impedance R1of the branch ventilation channel1is minimum and the impedance R8of the branch ventilation channel8is maximum), which can improve the uniformity of the quantities Q of the airflow flowing through the multiple ventilation channels13. By adjusting the impedances R of the multiple ventilation channels13, the quantities Q of the airflow flowing through the multiple ventilation channels13are enabled to be the same. The impedances R of the ventilation channels13are adjusted according to the following principle: if the quantity of the airflow flowing through a ventilation channel13is large, the impedance R of this ventilation channel13is increased; if the quantity of the airflow flowing through a ventilation channel13is small, the impedance R of this ventilation channel13is decreased, and the sum of the impedances R of the multiple ventilation channels13is constant.

In the radial ventilation cooling structure for the motor according to this embodiment of the present application, the impedances of the multiple ventilation channels are gradually increased in the direction from the two ends of the motor to the center of the motor, which improves the uniformity of the quantities of the airflow flowing through the multiple ventilation channels, and in turn improves the uniformity of the temperature distribution of the coils and the multiple core sections in the axial direction of the motor. Therefore, the maximum temperature value is reduced without changing the total quantity of the airflow, which effectively avoids the shutdown of the motor caused by the excessive local temperature rise and at the same time reduces the thermal deformation of the core bracket, thereby ensuring the normal operation of the motor.

Second Embodiment

Referring to the conventional radial ventilation cooling structure for the motor shown inFIG. 1, the radial ventilation cooling structure for the motor according to this embodiment of the present application also includes at least three core sections11, a ventilation channel steel12is provided between every two adjacent core sections11, and a ventilation channel13is formed between the ventilation channel steel12and the every two adjacent core sections11. However, unlike the conventional radial ventilation cooling structure for the motor, in the radial ventilation cooling structure for the motor according to this embodiment of the present application, the multiple ventilation channel steels12and/or the multiple core sections11have different structures, thus the impedances R of the multiple ventilation channels13are gradually increased in the direction from two ends of the motor to the center of the motor, and the impedances S of the ventilation paths where the multiple ventilation channels13are located are equal. The impedance S of each of the ventilation paths is equal to the sum of the impedance R of the respective ventilation channel13in the ventilation path and the impedance of a respective air gap14in the ventilation path.

Referring toFIG. 3, the branches a→a1→b, a→a2→b, . . . , a→a8→b are respectively the ventilation paths where the branch ventilation channels1,2, . . . ,8are located. The flow distribution law of the parallel pipelines in fluid mechanics is as follow:

Therefore, the impedances S1, S2, . . . , S8of the branch ventilation paths where the branch ventilation channels1,2, . . . ,8are located are equal, which allows the quantities Q1, Q2, . . . , Q8of the airflow flowing through the branch ventilation channels1,2, . . . ,8to be the same, that is, the impedances S of the ventilation paths where the multiple ventilation channels13are located are equal, which allows the quantities Q of the airflow flowing through the multiple ventilation channels13to be the same.

In the radial ventilation cooling structure for the motor according to this embodiment of the present application, the impedances of the multiple ventilation channels are gradually increased in the direction from the two ends of the motor to the center of the motor, and the impedances of the ventilation paths where the multiple ventilation channels are located are equal, thus the quantities of the airflow flowing through the multiple ventilation channels are the same, which improves the uniformity of the quantities of the airflow flowing through the multiple ventilation channels, and in turn improves the uniformity of the temperature distribution of the coils and the multiple core sections in the axial direction of the motor. Therefore, the maximum temperature value is reduced without changing the total quantity of the airflow, which effectively avoids the shutdown of the motor caused by the excessive local temperature rise and at the same time reduces the thermal deformation of the core bracket, thereby ensuring the normal operation of the motor.

Third Embodiment

As shown inFIGS. 4 and 5, based on the first embodiment and the second embodiment, the radial ventilation cooling structure for the motor according to this embodiment provides a manner of adjusting the size of the ventilation channel steel12(including a height h in the axial direction of the motor and/or a width w in a circumferential direction of the motor), to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor.

The ventilation channel steel12in this embodiment is still an integral bar-shaped ventilation channel steel in the shape of a straight line shape.

As the height h of the ventilation channel steel12increases, the impedance R of the corresponding ventilation channel13is decreased; and as the height h of the ventilation channel steel12decreases, the impedance R of the corresponding ventilation channel13is increased. Therefore, the heights h of the multiple ventilation channel steels12can be adjusted to be gradually decreased in the direction from the two ends of the motor to the center of the motor, to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor. Preferably, to avoid affecting the electromagnetic performance of the motor, the sum of the heights h of the multiple ventilation channel steels12is constant after the size adjustment compared with the sum of the heights h before the size adjustment.

As the width w of the ventilation channel steel12increases, the impedance R of the corresponding ventilation channel13is increased; and as the width w of the ventilation channel steel12decreases, the impedance R of the corresponding ventilation channel13is decreased. Therefore, the widths w of the multiple ventilation channel steels12can be adjusted to be gradually increased in the direction from the two ends of the motor to the center of the motor, to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor.

Preferably, to avoid affecting the electromagnetic performance of the motor as much as possible, the height h of each of the ventilation channel steels12cannot be too large, and should not be greater than 10 mm.

Preferably, in order to prevent each of the ventilation channels13from being blocked after it is baked with the vacuum pressure impregnating process (Vacuum Pressure Impregnating, abbreviated as VPI), the width w of each of the ventilation channel steels12cannot be too large, and should be less than the width of the core tooth by 12 mm or more. The height h of each of the ventilation channel steels12cannot be too small, and should not be less than 6 mm.

It is to be noted here that the impedances R of the multiple ventilation channels13may be enabled to gradually increase in the direction from the two ends of the motor to the center of the motor by only adjusting the height h of each of the ventilation channel steels12, or only adjusting the width w of each of the ventilation channel steels12, or adjusting both the heights h and the widths w of the multiple ventilation steel grooves12(for example, firstly adjusting the heights h of the multiple ventilation channel steels12and then finely adjusting the widths w of the multiple ventilation channel steels12), or adjusting the heights h of a part of the ventilation channel steels12and the widths w of a part of the ventilation channel steels12.

For example, in a manner of adjusting both the heights h and the widths w of the multiple ventilation steel grooves12, the sizes of the multiple ventilation channel steels12are shown in Table 1:

As shown inFIG. 6, which is a schematic view comparing the simulation calculation results of the quantities of the airflow flowing through the multiple ventilation channels after the heights h and the widths w of the multiple ventilation steel grooves are adjusted according to the sizes in Table 1 with the simulation calculation results of the quantities of the airflow flowing through the multiple ventilation channels before the sizes of the multiple ventilation steel grooves are adjusted. As can be seen fromFIG. 6, by adjusting the heights h and the widths w of the multiple ventilation channel steels, the impedances R of the multiple ventilation channels13are adjusted to be gradually increased in the direction from the two ends of the motor to the center of the motor, which improves the uniformity of the quantities Q of the airflow flowing through the multiple ventilation channels13. With further adjustment, the quantities Q of the airflows flowing through the multiple ventilation channels13can be enabled to be the same.

In the radial ventilation cooling structure for the motor according to this embodiment of the present application, the impedances of the multiple ventilation channels are gradually increased in the direction from the two ends of the motor to the center of the motor by adjusting the heights h and/or the widths w of the multiple ventilation channel steels, thereby improving the uniformity of the quantities of the airflow flowing through the multiple ventilation channels, and in turn improving the uniformity of the temperature distribution of the coils and the multiple core sections in the axial direction of the motor. Therefore, the maximum temperature value is reduced without changing the total quantity of the airflow, which effectively avoids the shutdown of the motor caused by the excessive local temperature rise and at the same time reduces the thermal deformation of the core bracket, thereby ensuring the normal operation of the motor.

Fourth Embodiment

As shown inFIGS. 7 to 10, based on the first embodiment or the second embodiment, the radial ventilation cooling structure for the motor according to this embodiment provides manners to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor by arranging sections (the number n of the sections is different and/or the distances Δh between the sections in the radial direction of the motor are different) of the ventilation channel steel12in different arrangements (including linearly arranging the sections, staggering the sections, arranging the sections in the form of a character “”, arranging the sections arranged in the form of an inverted character “”).

The ventilation channel steel12in this embodiment includes multiple separate ventilation channel steel sections121having the same structure. Each of the ventilation channel steel sections121is an integral bar-shaped ventilation channel steel section in the form of a straight line shape. The distances Δh between ventilation channel steel sections121, adjacent in the radial direction of the motor, of the same ventilation channel steel12are the same. The sections of the ventilation channel steel12may be arranged linearly as shown inFIG. 7, or staggered as shown inFIG. 8, or arranged in the form of a character “” as shown inFIG. 9, or arranged in the form of an inverted character “” as shown inFIG. 10.

As the number n of the ventilation channel steel sections121of the ventilation channel steel12increases, the impedance R of the corresponding ventilation channel13is increased; and as the number n of the ventilation channel steel sections121of the ventilation channel steel12decreases, the impedance R of the corresponding ventilation channel13is decreased. Therefore, the number n of the ventilation channel steel sections121of the multiple ventilation channel steels12can be adjusted to be gradually increased in the direction from the two ends of the motor to the center of the motor, to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor.

As the distance Δh between the ventilation channel steel sections121in the same ventilation channel steel12increases, the impedance R of the corresponding ventilation channel13is decreased; and as the distance Δh between the ventilation channel steel sections121in the same ventilation channel steel12decreases, the impedance R of the corresponding ventilation channel13is increased. Therefore, the distance Δh between the ventilation channel steel sections121of the multiple ventilation channel steels12can be adjusted to be gradually decreased in the direction from the two ends of the motor to the center of the motor, to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor.

It is to be noted here that the impedances R of the multiple ventilation channels13may be adjusted to gradually increase in the direction from the two ends of the motor to the center of the motor by only adjusting the number n of the ventilation channel steel sections121of each of the ventilation channel steels12, or only adjusting the distance Δh between the ventilation channel steel sections121of each of the ventilation channel steels12, or adjusting both the number n of the ventilation channel steel sections121and the distance Δh between the ventilation channel steel sections121of the multiple ventilation steel grooves12(for example, firstly adjusting the number n of the ventilation channel steel sections121of the multiple ventilation channel steels12and then finely adjusting the distance Δh between the ventilation channel steel sections121of the multiple ventilation channel steels12), or adjusting the heights h of a part of the ventilation channel steels12and the widths w of a part of the ventilation channel steels12. The multiple ventilation channel steels12may have the same arrangement or different arrangements, that is, the arrangement of the multiple ventilation channel steels12may employ any one or a combination of the following arrangements: arranging the sections linearly as shown inFIG. 7, or staggering the sections as shown inFIG. 8, or arranging the sections in the form of a character “” as shown inFIG. 9, or arranging the sections in the form of an inverted character “” as shown mFIG. 10.

As can be known from simulation calculation, by adjusting the number n of the ventilation channel steel sections121and/or the distance Δh between the ventilation channel steel sections121in the multiple ventilation channel steels12and/or the arrangement of the multiple ventilation channel steels12, the impedances R of the multiple ventilation channels13are adjusted to gradually increase in the direction from the two ends of the motor to the center of the motor, which can improve the uniformity of the quantities Q of the airflow flowing through the multiple ventilation channels13. With further adjustment, the quantities Q of the airflow flowing through the multiple ventilation channels13are enabled to be the same.

In the radial ventilation cooling structure for the motor according to this embodiment of the present application, the impedances of the multiple ventilation channels are enabled to gradually increase in the direction from the two ends of the motor to the center of the motor by adjusting the number a of the ventilation channel steel sections and/or the distance Ah between the ventilation channel steel sections in the multiple ventilation channel steels and/or the arrangement of the multiple ventilation channel steels, thereby improving the uniformity of the quantities of the airflow flowing through the multiple ventilation channels, and in turn improving the uniformity of the temperature distribution of the coils and the multiple core sections in the axial direction of the motor. Therefore, the maximum temperature value is reduced without changing the total quantity of the airflow, which effectively avoids the shutdown of the motor caused by the excessive local temperature rise and at the same time reduces the thermal deformation of the core bracket, thereby ensuring the normal operation of the motor. In addition, each of the multiple ventilation channel steels is sectioned, which can effectively suppress the growth of the boundary layer, thereby enhancing the heat transfer and further reducing the temperature of the coils and the multiple core sections.

Fifth Embodiment

As shown inFIG. 11, based on the first embodiment or the second embodiment, the radial ventilation cooling structure for the motor according to this embodiment provides a manner to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor by configuring each of the multiple ventilation channel steels12in the form of an integral S shape and adjusting the maximum widths wmaxof the multiple ventilation channel steels12in the circumferential direction of the motor and/or the numbers m of the turns of the multiple ventilation channel steels12and/or the bending angles θ of the turns of the multiple ventilation channel steels12.

The ventilation channel steel12in this embodiment is a bar-shaped ventilation channel steel in the form of an integral S shape. Multiple turns of the same ventilation channel steel12have the same bending angle θ.

As the maximum width wmaxof the ventilation channel steel12increases, the impedance R of the corresponding ventilation channel13is increased; and as the maximum width wmaxof the ventilation channel steel12decreases, the impedance R of the corresponding ventilation channel13is decreased. Therefore, the maximum widths wmaxof the multiple ventilation channel steels12can be adjusted to be gradually increased in the direction from the two ends of the motor to the center of the motor, to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor.

As the number m of the turns of the ventilation channel steel12increases, the impedance R of the corresponding ventilation channel13is increased; and as the number m of the turns of the ventilation channel steel12decreases, the impedance R of the corresponding ventilation channel13is decreased. Therefore, the numbers m of the turns of the multiple ventilation channel steels12can be adjusted to be gradually increased in the direction from the two ends of the motor to the center of the motor, to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor.

As the bending angle θ of the turns of the ventilation channel steel12increases, the impedance R of the corresponding ventilation channel13is decreased; and as the bending angle θ of the turns of the ventilation channel steel12decreases, the impedance R of the corresponding ventilation channel13is increased. Therefore, the bending angle θ of the turns of the multiple ventilation channel steels12can be adjusted to be gradually decreased in the direction from the two ends of the motor to the center of the motor, to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor.

It is to be noted here that the impedances R of the multiple ventilation channels13may be enabled to gradually increase in the direction from the two ends of the motor to the center of the motor by only adjusting the maximum width wmaxof each of the ventilation channel steels12, or only adjusting the number m of the turns of each of the ventilation channel steels12, or only adjusting the bending angle θ of the turns of each of the ventilation channel steels12, or adjusting both the maximum widths wmaxand the numbers m of the turns of the multiple ventilation channel steels12, or adjusting both the maximum widths wmaxand the bending angles θ of the turns of the multiple ventilation channel steels12, or adjusting both the numbers m of the turns and the bending angles θ of the turns of the multiple ventilation channel steels12, or adjusting the maximum widths wmax, the numbers m of the turns, and the bending angles θ of the turns of the multiple ventilation channel steels12at the same time, or adjusting the maximum widths wmaxof a part of the ventilation channel steels12, the numbers m of the turns of a part of the ventilation channel steels12, and the bending angles θ of the turns of a part of the ventilation channel steels12.

As can be known from simulation calculation, by adjusting the maximum width wmaxand/or the number m of the turns and/or the bending angle θ of the turns of the multiple ventilation channel steels12, the impedances R of the multiple ventilation channels13are adjusted to be gradually increased in the direction from the two ends of the motor to the center of the motor, which can improve the uniformity of the quantities Q of the airflow flowing through the multiple ventilation channels13. With further adjustment, the quantities Q of the airflow flowing through the multiple ventilation channels13are enabled to be the same.

In the radial ventilation cooling structure for the motor according to this embodiment of the present application, the impedances of the multiple ventilation channels are enabled to gradually increase in the direction from the two ends of the motor to the center of the motor by adjusting the maximum widths wmaxand/or the number m of the turns and/or the bending angles θ of the turns of the multiple ventilation channel steels, thus improving the uniformity of the quantities of the airflow flowing through the multiple ventilation channels, and in turn improving the uniformity of the temperature distribution of the coils and the multiple core sections in the axial direction of the motor. Therefore, the maximum temperature value is reduced without changing the total quantity of the airflow, which effectively avoids the shutdown of the motor caused by the excessive local temperature rise and at the same time reduces the thermal deformation of the core bracket, thereby ensuring the normal operation of the motor. In addition, by configuring each of the multiple ventilation channel steels to be in the form of an integral S shape, the growth of the boundary layer can be effectively suppressed, thereby enhancing the heat transfer and further reducing the temperature of the coils and the multiple core sections.

Sixth Embodiment

As shown inFIG. 12, based on the first embodiment or the second embodiment, the radial ventilation cooling structure for the motor according to this embodiment provides a manner to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor by communicating the multiple ventilation channels13with each other.

The radial ventilation cooling structure for the motor according to this embodiment is additionally provided with a ventilation hole111based on the radial ventilation cooling structure for the motor shown inFIG. 1. The core section11located between any two ventilation channels13is provided with the ventilation hole111in the axial direction of the motor. The ventilation hole111is configured to communicate the two ventilation channels13at two sides of the core section11, as shown inFIG. 13. In order to ensure the multiple ventilation channels13to be in communication with each other, the ventilation channel steel12may be sectioned.

Preferably, to avoid affecting the electromagnetic performance of the motor as much as possible and to ensure that the ventilation channels13and the ventilation holes111will not blocked after being baked by the vacuum pressure impregnating VPI process, the diameter of each of the ventilation holes111should be ranged from 4 mm to 8 mm, inclusive. The number of the ventilation holes111in each of the core tooth portion should not be greater than three.

Preferably, the ventilation hole111is arranged in the core section11at a portion near the air inlet of the ventilation channel13, that is, near the air gap14.

Optionally, the ventilation holes111in different core sections11may have different altitudes in the radial direction of the motor.

As can be known from simulation calculation, by adjusting the diameters of the multiple ventilation holes111and/or the number of the ventilation holes111and/or the altitudes of the ventilation holes111in the core section11, the impedances R of the multiple ventilation channels13can be adjusted to be gradually increased in the direction from the two ends of the motor to the center of the motor, which can improve the uniformity of the quantities Q of the airflow flowing through the multiple ventilation channels13. With further adjustment, the quantities Q of the airflows flowing through the multiple ventilation channels13are enabled to be the same.

In the radial ventilation cooling structure for the motor according to this embodiment of the present application, the impedances of the multiple ventilation channels are enabled to gradually increase in the direction from the two ends of the motor to the center of the motor by communicating the multiple ventilation channels with each other and adjusting the diameters of the multiple ventilation holes and/or the number of the ventilation holes and/or the altitudes of the ventilation holes in the core sections, thus improving the uniformity of the quantities of the airflow flowing through the multiple ventilation channels, and in turn improving the uniformity of the temperature distribution of the coils and the multiple core sections in the axial direction of the motor. Therefore, the maximum temperature value is reduced without, changing the total quantity of the airflow, which effectively avoids the shutdown of the motor caused by the excessive local temperature rise and at the same time reduces the thermal deformation of the core bracket, thereby ensuring the normal operation of the motor.

Seventh Embodiment

As shown inFIG. 14, based on the first embodiment or the second embodiment, the radial ventilation cooling structure for the motor according to this embodiment provides a manner to allow the impedances R of the multiple ventilation channels13to gradually increase in the direction from the two ends of the motor to the center of the motor by providing each of multiple core sections11with a chamfer structure112.

The radial ventilation cooling structure for the motor according to this embodiment additionally arranges the chamfer structures112on multiple core sections11based on the radial ventilation cooling structure for the motor shown inFIG. 1. The chamfer structure112is arranged on the core section11at a portion near the air inlet of the ventilation channel13, that is, near the air gap14, to reduce the local drag at the air inlet of each of the multiple ventilation channels13. Moreover, the widths of openings of the multiple chamfer structures112are gradually reduced in the direction from the two ends of the motor to the center of the motor, and the local drags at the air inlets of the multiple ventilation channels13are gradually increased in the direction from the two ends of the motor to the center of the motor, thus the impedances R of the multiple ventilation channels13are gradually increased in the direction from the two ends of the motor to the center of the motor, which can improve the uniformity of the quantities Q of the airflow flowing through the multiple ventilation channels13. With further adjustment, the quantities Q of the airflow flowing through the multiple ventilation channels13are enabled to be the same.

As shown inFIG. 15, since the core section11is formed by laminating multiple stamped sheets113, the laminated core section11can be formed with the step-shaped chamfer structure112by adjusting the tooth radial height of each of the stamped sheets113.

In the radial ventilation cooling structure for the motor according to this embodiment of the present application, the impedances of the multiple ventilation channels are enabled to gradually increase in the direction from the two ends of the motor to the center of the motor by providing chamfer structures on the multiple core sections, thus improving the uniformity of the quantities of the airflow flowing through the multiple ventilation channels, and in turn improving the uniformity of the temperature distribution of the coils and the multiple core sections in the axial direction of the motor. Therefore, the maximum temperature value is reduced without changing the total quantity of the airflow, which effectively avoids the shutdown of the motor caused by the excessive local temperature rise and at the same time reduces the thermal deformation of the core bracket, thereby ensuring the normal operation of the motor.

Eighth Embodiment

The ventilation channel steels12can be divided into multiple groups. As shown inFIG. 16, based on the first embodiment or the second embodiment, the ventilation channel steels12are divided into multiple groups, and the ventilation channel steels in each of the dashed boxes shown inFIG. 16belong to one group, and each group has at least one of the ventilation channel steels12. The ventilation channel steels12in each group have the same shape and the same arrangement, and the ventilation channel steels12in the multiple groups employ any one or a combination of the following shapes and arrangements: an integral straight line shape as shown inFIG. 5, arranging sections linearly as shown inFIG. 7, or staggering sections as shown inFIG. 8, arranging sections in the form of a character “” as shown inFIG. 9, arranging sections in the form of an inverted character “” as shown inFIG. 10, or an integral S shape as shown inFIG. 11. Preferably, the above solution can also be combined with the solution of the sixth embodiment shown inFIGS. 12 to 13in which the multiple ventilation channels13are in communication with each other and/or the solution of the seventh embodiment shown inFIGS. 14 to 15in which the chamfer structures112are provided on the multiple core sections11.

Ninth Embodiment

The ventilation channel steel12can employ any one or a combination of the following shapes and arrangements: an integral straight line shape as shown inFIG. 5, arranging sections linearly as shown inFIG. 7, staggering sections as shown inFIG. 8, arranging sections in the form of a character “” as shown inFIG. 9, arranging sections in the form of an inverted character “” as shown inFIG. 10, or an integral S shape as shown inFIG. 11. Preferably, the above solution can also be combined with the solution of the sixth embodiment shown inFIGS. 12 to 13in which the multiple ventilation channels13are in communication with each other and/or the solution of the seventh embodiment shown inFIGS. 14 to 15in which the chamfer structures112are provided on the multiple core sections11.

The above descriptions are only the specific embodiments of the present application. However, the scope of protection of the present application is not limited thereto, and any variations or substitutions easily made by the person skilled in the art within the technical scope disclosed by the present application are deemed to fall into the scope of protection of the present application. Therefore, the scope of protection of the present application is defined by the claims.