WO2023092805A1

WO2023092805A1 - Cooling mode and cooling structure of internal circulation evaporative cooling motor

Info

Publication number: WO2023092805A1
Application number: PCT/CN2021/142501
Authority: WO
Inventors: 张江涛; 吴楠; 蔡晓; 孙德强; 倪伟; 李嘉宾
Original assignee: 中车永济电机有限公司
Priority date: 2021-11-29
Filing date: 2021-12-29
Publication date: 2023-06-01
Also published as: CN114337111B; CN114337111A

Abstract

The present application relates to a cooling mode and a cooling structure of an internal circulation evaporative cooling motor. The cooling mode comprises liquid cooling and air cooling. An independent sealing cavity is formed between each of the two end surfaces of a motor stator and a machine base, and a corresponding inner end cover; an evaporative cooling working medium is injected into the sealing cavities at two ends; the stator is axially provided with a liquid cooling channel; the circulating cooling of the stator portion of the motor is realized by means of an external evaporative cooling circulation system; the motor stator and the sealing cavities at the two ends are axially provided with an air cooling channel; a rotor is axially provided with a rotor ventilation channel; and an air cooling circulation loop is formed between the air cooling channel, an air gap between the rotor and the stator, and the rotor ventilation channel. According to the present application, a liquid cooling pipe is arranged at the yoke portion of a stator core, and the liquid cooling pipe is attached to an iron core in a cold pressing mode; the yoke portion of the stator core is provided with an air cooling pipe so as to form a stator cooling air path structure; and the yoke portion of a rotor iron is provided with a rotor ventilation channel, and the evaporative cooling medium in the stator is used to cool the circulating air of a rotor portion, so that the temperature rise of the rotor portion is reduced.

Description

A cooling method and cooling structure of an internal circulation evaporative cooling motor

Cross References to Related Applications

This application is based on a Chinese patent application with application number 202111430667.1 and a filing date of November 29, 2021, and claims the priority of this Chinese patent application. The entire content of this Chinese patent application is hereby incorporated by reference into this application.

technical field

The present application relates to the field of traction motor cooling structure, in particular to a cooling method and cooling structure of an internal circulation evaporative cooling motor.

Background technique

In recent years, with the rapid development of rail transit at home and abroad, new technologies in this field have also shown a rapid development trend. The traction motor is one of the core components of the rail transit vehicle, which is used for traction and braking of the vehicle. With the development and progress of technology, the requirements for the following aspects of the rail transit traction motor are getting higher and higher:

(1) Compact shape: Since the traction motor is installed on the lower side of the bogie, the size of the traction motor is getting smaller and smaller due to the space layout on the lower side of the bogie and the vehicle boundary requirements, and miniaturization is a development trend.

(2) Light weight: The light weight of the traction motor can not only improve the running stability of the vehicle, but also improve the energy saving of the system due to the reduced weight of the whole vehicle.

(3) High power and high torque: The increase in the running speed and carrying capacity of rail vehicles requires the power and torque of the traction motor to increase.

In order to meet the above requirements, the traction motor needs to adopt a high electromagnetic load, which brings challenges to the cooling design of the motor. The existing forced air cooling and water cooling methods in the field of rail transit are difficult to meet the heat dissipation requirements of traction motors, and more efficient cooling methods have become the needs of industry development. Evaporative cooling technology is one of the more advanced cooling methods at present. It uses the principle of liquid medium vaporization (phase change) to absorb heat to cool the motor. The cooling effect is greatly improved and it can meet the heat dissipation requirements of the traction motor.

The motor cooling structure of the existing evaporative cooling technology (as shown in Figure 1) includes an inner end cover 6 fixed circumferentially on both ends of the inner wall of the machine base 1, which is sleeved between the rotor 2 and the stator 3, and the two ends are respectively connected to the front and rear. The inner end cover 6 is sealed with the sealing cylinder 4, and the two ends of the sealing cylinder 4 form a closed stator cavity through the support member 7 and the front and rear inner end covers 6 respectively, and the entire stator 3 is sealed. In the stator cavity, the evaporative cooling medium is injected into the stator cavity, and the stator cavity is filled with the evaporative cooling medium. This evaporative cooling method only cools the stator of the motor, and no cooling measures are used for the rotor of the motor, so the problem of rotor temperature rise cannot be solved.

Contents of the invention

In order to solve the temperature rise problem of the motor rotor, the present application provides a cooling method and a cooling structure for an internal circulation evaporative cooling motor.

This application is achieved through the following technical solutions: on the one hand, it provides a cooling method for internal circulation evaporative cooling motors, including liquid cooling methods and gas cooling methods;

The liquid cooling method includes: there are independent sealed cavities between the two ends of the stator of the motor, the machine base and the opposite inner end cover, and evaporative cooling fluid is injected into the sealed cavities at both ends, and the stator In the axial direction, there is at least one liquid cooling channel for evaporative cooling working fluid to flow through the sealed cavity at both ends, and the circulating cooling of the stator part of the motor is realized through the external evaporative cooling circulation system;

The gas cooling method includes: the stator of the motor and the sealed cavity at both ends have at least one through gas cooling passage in the axial direction, and the rotor has at least one through rotor air passage in the axial direction, the gas cooling passage, the An air cooling circulation loop is formed between the air gap between the rotor and the stator and the air duct of the rotor.

As a further improvement of the technical solution of the motor cooling method of the present application, the air cooling circulation circuit in the gas cooling method has an internal circulation fan.

As a further improvement of the technical solution of the motor cooling method of the present application, the evaporative cooling working fluid does not directly contact with the stator of the motor.

Another aspect of the present application provides a cooling structure for an internal circulation evaporative cooling motor, including a liquid cooling structure. The air outlet and liquid return port on the base outside the end, and the motor cooling structure also includes a gas cooling structure;

The liquid cooling structure also includes: a sealing cylinder 2 arranged circumferentially between the inner edge of the stator tooth pressure plate and the inner edge of the corresponding inner end cover, at least one liquid cooling pipe axially penetrating through the stator, and the motor The machine base, the inner end caps at both ends and the sealing cylinder are arranged to form independent sealed cavities at both ends of the stator, and each of the liquid cooling tubes can communicate with the sealed cavities at both ends;

The gas cooling structure includes: at least one air-cooled pipe axially penetrating through the stator and the sealed cavity at both ends, at least one rotor air duct axially arranged on the rotor, each of the air-cooled pipes can communicate The area between the sealed cavity and the end cover, each of the rotor air passages can communicate with the area between the rotor and the end cover, the air-cooled pipe is connected to the rotor air passage, the rotor and An air cooling circulation loop is formed between the air gaps between the stators.

As a further improvement of the technical solution of the motor cooling structure of the present application, the air cooling circulation loop of the gas cooling structure includes an internal circulation fan.

As a further improvement of the technical solution of the motor cooling structure of the present application, the machine base is a fully laminated welded machine base structure.

As a further improvement of the technical solution of the motor cooling structure of the present application, the outer end surface of the stator tooth pressure plate is potted with a sealant layer.

As a further improvement of the technical solution of the motor cooling structure of the present application, the air-cooled pipe is sealed and connected to the stator pressure ring and the inner end cover respectively through sealing rings.

As a further improvement of the technical solution of the motor cooling structure of the present application, the liquid cooling pipe and the stator pressure ring are connected in a sealed manner by brazing.

As a further improvement of the technical solution of the motor cooling structure of the present application, the end cover of the motor is inclined inward near the rotating shaft.

The cooling structure of the internal circulation evaporative cooling motor described in this application efficiently cools the stator and the rotor at the same time, and is especially suitable for direct-drive traction motors of rail vehicles. This application adopts evaporative cooling technology, and compared with the existing forced air cooling and water cooling methods in the rail transit field, the cooling efficiency will be greatly improved. The motor adopts a fully laminated welded frame with a small footprint, and the one-piece frame structure is eliminated, which has the advantages of good manufacturability, low processing cost, short cycle time, and light weight. The yoke of the stator core is equipped with a liquid cooling tube, and the cold pressing method is used to make the liquid cooling tube fit the iron core, the liquid cooling tube and the stator pressure ring are sealed, and the evaporative cooling medium is filled with the liquid cooling tube. On the one hand, the cooling of the stator core is improved. The effect, on the other hand, is to prevent the leakage of evaporative cooling medium from the slots of the stator laminations. The yoke of the stator core is equipped with air-cooled pipes, and the air-cooled pipes are sealed with the inner end covers at both ends and the stator pressure ring to prevent the evaporative cooling medium from entering the gap between the rotor and the stator punching plates, and constitute the structure of the rotor cooling air path . The yoke of the rotor core is provided with a rotor ventilation channel, and an internal circulation fan is installed on the shaft, which forms an internal circulation cooling system together with the axial cooling air path of the stator core. The evaporative cooling medium in the stator is used to cool part of the circulating air of the rotor and reduce the temperature rise of the rotor part. .

Description of drawings

In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the specific embodiments or prior art. Obviously, the accompanying drawings in the following description The figures show some implementations of the present application, and those skilled in the art can obtain other figures based on these figures without any creative effort.

FIG. 1 is a structural schematic diagram of a motor cooling structure in the prior evaporative cooling technology.

Fig. 2 is a cross-sectional view of the cooling structure of the internal circulation evaporative cooling motor according to the embodiment of the present application.

Fig. 3 is another cross-sectional view of the cooling structure of the internal circulation evaporative cooling motor.

Fig. 4 is a schematic diagram of cooperation between the liquid cooling tube and the stator pressure ring.

Detailed ways

The technical solutions of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

In the description of the present application, it should be noted that the terms "a" and "two" are used for description purposes only, and should not be understood as indicating or implying relative importance.

In the description of the embodiments of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a A detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediary, and it may be an internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the present application in specific situations.

As shown in Figure 2, on the one hand, the present application provides a cooling method for an internal circulation evaporative cooling motor, including a liquid cooling method and a gas cooling method;

The liquid cooling method includes: there are independent sealed cavities between the two ends of the stator 3 of the motor and the machine base 1 and the opposite inner end cover 6, and evaporative cooling fluid is injected into the sealed cavities at both ends, and the stator 3 is axially There is at least one liquid cooling passage for the evaporative cooling fluid to flow through the sealed cavity at both ends, and the circulating cooling of the stator part of the motor is realized through the external evaporative cooling circulation system;

The gas cooling method includes: the stator 3 of the motor and the sealed cavity at both ends have at least one through gas cooling passage in the axial direction, and the rotor 2 has at least one through rotor air passage 9 in the axial direction, the gas cooling passage, the rotor 2 An air cooling circulation loop is formed between the air gap between the stator 3 and the rotor air duct 9 .

In an embodiment of the present application, since the sealed cavity is filled with the evaporative cooling medium, the evaporative cooling medium can circulate between the two sealed cavities through the liquid cooling channel, and the external evaporative cooling circulation system realizes the cooling of the stator part of the motor. Circulation cooling. Since the stator 3 and the rotor 2 are respectively provided with a gas cooling channel and a rotor ventilation channel 9 in the axial direction, the high-temperature air in the rotor can be sent to the gas cooling channel through internal circulation ventilation, and after being cooled by the gas cooling channel, circulate to the rotor ventilation channel 9 to cool the rotor 2 and realize the circulation cooling of the rotor part of the motor.

Preferably, the liquid cooling tube 15 and the air cooling tube 16 are closely attached to the iron core punching sheet of the stator 3 by using extrusion technology, so as to eliminate gaps and improve heat dissipation efficiency. The liquid cooling tube 15 and the air cooling tube 16 used in this embodiment are copper tube structures.

In an embodiment of the present application, a plurality of liquid cooling channels and gas cooling channels respectively form squirrel-cage evaporative cooling working medium circulation channels and gas circulation channels on the stator 3, which increases the heat dissipation area and improves heat dissipation efficiency. Said liquid cooling channels and gas cooling channels are located on the yoke of the stator 3 . All liquid cooling channels are located on the same circumference of the stator 3, and all gas cooling channels are located on the same circumference of the stator 3.

Specifically, in order to prevent the evaporative cooling working medium from entering the stator 3 and leaking in the gaps of the iron core stamping sheets, the evaporative cooling working medium is not in direct contact with the stator 3 of the motor.

In a specific application, in order to improve the cooling effect, each sealed cavity can cover more than 80% of the corresponding end surface of the stator 3 .

In order to enhance the cooling effect of the rotor 2, an internal circulation fan 10 is provided in the air-cooling circulation circuit in the gas cooling mode. The internal circulation fan 10 can speed up the flow rate of gas in the air-cooling circulation circuit, and improve the circulation cooling effect of the rotor part of the motor.

In order to realize the above-mentioned cooling method, another aspect of the present application provides a specific implementation method, which is as follows:

A cooling structure for an internal circulation evaporative cooling motor, including a liquid cooling structure, the liquid cooling structure includes inner end covers 6 circumferentially fixed to both ends of the inner wall of the motor frame 1, respectively set on the outer sides of the two ends of the stator 3. The air outlet 11 and the liquid return port 12 on the seat 1, the motor cooling structure also includes a gas cooling structure;

The liquid cooling structure also includes: a sealing cylinder 2 14 circumferentially arranged between the inner edge of the stator tooth pressure plate 13 and the inner edge of the corresponding inner end cover 6, at least one liquid cooling tube 15 (liquid cooling pipe 15) axially penetrating the stator 3 Cooling channel), the frame 1 of the motor, the inner end caps 6 at both ends and the sealing cylinder 2 14 are set to form independent sealed cavities at both ends of the stator 3, and each liquid cooling tube 15 can communicate with the sealed cavities at both ends. Cavity;

The gas cooling structure includes: at least one air-cooled tube 16 (gas cooling channel) axially penetrating the stator 3 and the sealed cavity at both ends, at least one rotor air channel 9 axially arranged on the rotor 2, each wind The cold pipes 16 can communicate with the area between the sealed cavity and the end cover 8, and each rotor air channel 9 can communicate with the area between the rotor 2 and the end cover 8. An air-cooled circulation loop is formed between the air gap and the stator 3.

Specifically, the air outlet 11 and the liquid return port 12 are connected to an external evaporative cooling cycle system to form a motor evaporative cooling cycle system.

In order to improve the circulation cooling effect of the rotor 2 , the air cooling circulation loop of the gas cooling structure includes an internal circulation fan 10 . In an embodiment of the present application, the internal circulation fan 10 is installed on the rotating shaft 5 below the air outlet 11, and the gap between the internal circulation fan 10 and the rotor 2 is small, so that the ventilation effect of the fan can be ensured. During specific use, the gas in the air gap between the rotor air channel 9, the rotor 2 and the stator 3 is sent to one end of the air-cooled pipe 16 below the air outlet 11 by the internal circulation fan 10, and the evaporative cooling working medium passes through the air-cooled pipe 16 to The internal gas is cooled, and after passing through the air-cooled pipe 16 , the cooled gas is sent back to one end of the rotor 2 located below the liquid return port 12 .

In an embodiment of the present application, in order to form an independent sealed cavity structure, the outer edge and inner edge of the inner end cover 6 are respectively sealed and connected to the machine base 1 and the outer end of the sealing cylinder 2 14, and the sealing cylinder The inner end of the second 14 is sealed and connected with the inner edge of the stator tooth pressure plate 13 . The air-cooled pipe 16 is sealed and connected to the stator pressure ring 18 and the inner end cover 6 respectively through sealing rings. The liquid cooling pipe 15 and the stator pressure ring 18 are hermetically connected by brazing 19 . The above-mentioned sealing method can effectively prevent the evaporative cooling working medium from leaking from the sealed cavity to the inside of the base 1 .

In specific applications, as shown in Figure 2, one end of the air-cooled pipe 16 has a stepped outer edge, and the other end has a threaded structure. After the air-cooled pipe 16 is inserted into the stator 3, a sealing round gasket 22 and a tight The solid nut 21 fastens and seals the other end of the air-cooled pipe 16, which can be easily disassembled.

In an embodiment of the present application, in order to avoid direct contact between the evaporative cooling working fluid and the stator 3 of the motor, the outer end surface of the stator tooth pressure plate 13 is potted with a sealant layer 17 . The above-mentioned sealing method can effectively prevent the evaporative cooling working fluid from entering the stator 3 and then leaking from the gaps of the iron core punching sheets.

The machine base 1 of an embodiment of the present application adopts a fully laminated welded machine base without an integrated machine base structure, thereby achieving light weight and reducing manufacturing costs. Air outlet 11 and liquid return port 12 are provided at both ends of machine base 1 respectively, and communicate with the external evaporative cooling circulation system to realize the circulation cooling of the stator part of the motor.

An embodiment of the present application further provides a fixing method of the sealing cylinder 14. The outer end surface of the stator tooth pressure plate 13 has a ring-inward installation groove, and a seal ring 20 is arranged in the ring-inward installation groove. The inner end of the second cylinder 14 is arranged in the circumferential installation groove and is in clearance fit with the sealing ring 20 , and two sealing rings are arranged between the inner end of the second sealing cylinder 14 and the sealing ring 20 . The inner end surface of the inner end cover 6 has a ring outward mounting groove, the outer end of the sealing cylinder 14 is arranged in the ring outward mounting groove, and the outer end of the sealing cylinder 2 14 and the inner end cover 6 There are two sealing rings in between. The way of adopting double seal rings can effectively realize the radial sealing between each other.

As shown in Figure 2, the sealing cylinder 14 in an embodiment of the present application adopts a cylindrical structure with a thick middle and thin ends, which can improve the manufacturability of parts and facilitate the finishing of both ends of the sealing cylinder 14 , to ensure the sealing performance.

During specific installation, after the stator tooth pressure plate 13, the sealing ring 20, the sealing cylinder 14 and the sealing ring are all assembled, the sealing compound is potted to ensure the sealing performance of the potting.

In an embodiment of the present application, the inner end of the sealing cylinder 2 14 is located outside the sealing ring 20 , and the height of the sealing ring 20 is higher than that of the sealant layer 17 . The inner end of the sealing cylinder 14 is set in the ring-inward installation groove, the outer end of the sealing cylinder 2 14 is arranged in the ring-outward installation groove, the installation places are closely matched, and the two ends of the sealing cylinder 14 are sealed and supported At the same time, structural reliability is provided.

As shown in FIGS. 2 and 3 , the end cover 8 of the motor is inclined inwardly near the rotating shaft 5 . The middle part of the end cover 8 forms an inner cone shape inward, which can reduce the internal circulation wind resistance on the one hand and reduce the axial dimension of the motor on the other hand.

As shown in FIG. 4 , in an embodiment of the present application, the sealing method of the brazing 19 may be potting sealant or a sealing ring. As shown in FIG. 4 a , a sealant is filled in the gap between the liquid cooling pipe 15 and the stator pressure ring 18 . As shown in FIG. 4 b , a sealing ring is provided between the liquid cooling pipe 15 and the stator pressure ring 18 .

As shown in Figures 2 and 3, the air-cooled tubes 16 and liquid-cooled tubes 15 in an embodiment of the present application are arranged at alternating intervals in the circumferential direction of the yoke of the stator 3 to achieve high-efficiency cooling, and at the same time reduce the size of the stator 3 too much. temperature difference.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present application. scope.

Claims

A cooling method for an internal circulation evaporative cooling motor, including a liquid cooling method and a gas cooling method;

The liquid cooling method includes: there are independent sealed cavities between the two ends of the stator (3) of the motor and the base (1) and the opposite inner end cover (6), and the sealed cavities at both ends The evaporative cooling working medium is injected, and the stator (3) has at least one liquid cooling channel in the axial direction for the evaporative cooling working medium to flow through the sealed cavities at both ends, and the stator (3) of the motor is realized through an external evaporative cooling circulation system. ) part of the circulating cooling;

The gas cooling method includes: the stator (3) of the motor and the sealed cavity at both ends have at least one through gas cooling passage in the axial direction, and the rotor (2) has at least one through rotor air passage (9) in the axial direction ), an air-cooling circulation loop is formed between the gas cooling channel, the air gap between the rotor (2) and the stator (3), and the rotor air channel (9).
According to the cooling mode of an internal circulation evaporative cooling motor according to claim 1, the air cooling circulation circuit in the gas cooling mode has an internal circulation fan (10).
According to the cooling method of an internal circulation evaporative cooling motor according to claim 1 or 2, the evaporative cooling working medium is not in direct contact with the stator (3) of the motor.
A cooling structure for an internal circulation evaporative cooling motor, including a liquid cooling structure, the liquid cooling structure includes inner end covers (6) circumferentially fixed to both ends of the inner wall of a machine base (1) of the motor, respectively opened on the stator (3 ) an air outlet (11) and a liquid return port (12) on the base (1) outside both ends, and the motor cooling structure also includes a gas cooling structure;

The liquid cooling structure also includes: a sealing cylinder 2 (14) arranged circumferentially between the inner edge of the stator tooth pressure plate (13) and the inner edge of the corresponding inner end cover (6), at least one of which axially passes through the stator (3) the liquid cooling pipe (15), the frame (1) of the motor, the inner end caps (6) at both ends and the sealing cylinder two (14) surround the stator (3) Independent sealed cavities at both ends, each of the liquid cooling tubes (15) can communicate with the sealed cavities at both ends;

The gas cooling structure includes: at least one air-cooled pipe (16) axially passing through the stator (3) and the sealed cavity at both ends, at least one rotor air channel (9) axially arranged on the rotor (2) ), each of the air-cooled pipes (16) can communicate with the area between the sealed cavity and the end cover (8), and each of the rotor air passages (9) can communicate with the rotor (2) and In the area between the end covers (8), the wind is formed between the air cooling pipe (16) and the rotor air channel (9), the air gap between the rotor (2) and the stator (3). Cold loop.
According to the internal circulation evaporative cooling motor cooling structure according to claim 4, the air cooling circulation circuit of the gas cooling structure comprises an internal circulation fan (10).
According to the cooling structure of an internal circulation evaporative cooling motor according to claim 4, the frame (1) is a fully laminated welded frame structure.
According to the cooling structure of an internal circulation evaporative cooling motor according to claim 4, the outer end surface of the stator tooth pressure plate (13) is potted with a sealant layer (17).
According to the cooling structure of an internal circulation evaporative cooling motor according to claim 4, the air-cooled pipe (16), the stator pressure ring (18), and the inner end cover (6) are respectively sealed and connected by sealing rings.
According to the cooling structure of an internal circulation evaporative cooling motor according to claim 4, the liquid cooling pipe (15) and the stator pressure ring (18) are hermetically connected by brazing (19).
According to the cooling structure of an internal circulation evaporative cooling motor according to claim 4, the end cover (8) of the motor is inclined inwardly near the rotating shaft (5).