WO2020034448A1

WO2020034448A1 - A fully-enclosed asynchronous traction motor for low-floor vehicle

Info

Publication number: WO2020034448A1
Application number: PCT/CN2018/114090
Authority: WO
Inventors: 庞聪; 胡彬; 李广; 王岩; 李海燕
Original assignee: 中车永济电机有限公司
Priority date: 2018-08-17
Filing date: 2018-11-06
Publication date: 2020-02-20
Also published as: CN108964354A

Abstract

A fully-enclosed asynchronous traction motor for a low-floor vehicle. An air duct is provided on a rotating-end end cap, a non-rotating end end cap, a rotating-end stator pressing ring, a non-rotating end stator pressing ring, a stator core, and a rotor core so as to form, inside the motor, an outer air path for cooling the stator core; a first inner air path for cooling the rotor core and an end of a stator winding; and a second inner air path for cooling an outer ring surface of the rotor core.

Description

Fully enclosed asynchronous traction motor for low-floor vehicles

Technical field

The invention relates to the field of electric motors for low-floor vehicles, and in particular to a fully enclosed asynchronous traction motor for low-floor vehicles.

Background technique

Low-floor light rail vehicles refer to rail transit vehicles where the height of the floor surface from the rail surface is generally 350 to 400 mm. The entrance height of this vehicle is very low, which makes it very convenient to get on and off, especially for the elderly, children and the disabled. Low-floor light rail vehicles do not need to be provided with high platforms, and the tracks can be laid directly on the pavement or use the original tramway tracks; vehicles can adapt to urban ground conditions through a curve with a small radius, which can significantly reduce the cost of the line. General low-floor light rail vehicles consist of 2 to 3 trains with a total length of 20 to 35 m and medium capacity. Low-floor vehicles are provided with a low-floor surface in the middle of the vehicle. The low-floor surfaces of each section of the car pass through each other, while the end of the train is a high-floor surface. The proportion of the low-floor surface to the entire vehicle's floor surface is 60% to 70%. Due to the installation size limitation of low-floor traction motors, compared with conventional urban rail and subway traction motors, the volume restrictions are more stringent, and the lightweight requirements are higher; the motors are closer to the track surface, more susceptible to foreign objects, and the protection level requirements for motors Higher, considering the adaptability of operation in high latitudes, the motor should be able to meet the requirements of -40 ° C.

The existing asynchronous traction motors used on low-floor vehicles mainly have the following two structures: The first motor uses a self-ventilating structure, the motor uses a single bearing and single fan structure, and the protection level is IP23. The ventilated opening structure is installed on the bottom of the low-floor car. Rainwater easily enters the interior of the motor through the air inlet and outlet, and then enters the interior of the junction box from the position of the lead wire, causing the three-phase lead wire to burn out. The second type of motor uses a fully enclosed structure for protection. The grade reaches IP54, the cooling method is IC41, the base is cast with nodular cast iron material, the stator core heat sleeve, the rotor is a squirrel-cage guide bar end ring welding structure, and the single-end bearing structure is used in conjunction with the gear box bearing. This structure solves The technical defects of the first structure are met, and the weight and electromagnetic performance of the motor can basically meet the requirements. However, the overall temperature rise of the motor is high and it cannot meet the long-term temperature rise assessment requirements of the motor. In order to solve the problem of the temperature rise of the totally enclosed motor, the existing one is improved on the basis of the second type of the totally enclosed motor structure. A self-ventilation as described in the patent application number "200810079856.7" has been developed. Traction motor. This type of motor is equipped with external air duct and internal air duct in order to solve the problem of temperature rise. However, the structure of the entire air duct depends on the machine base. The closed inner cavity of the fully enclosed motor passes the internal wind provided on the machine base. And external air ducts for heat dissipation. This heat dissipation structure can improve the temperature rise problem of the original fully enclosed structure motor. However, as the performance of the motor improves and the requirements for the heat dissipation structure increase, this improved structure can no longer meet the temperature rise. Requirements, and due to the setting of the machine base, the entire motor is bulky and cannot meet the requirements of light weight.

Summary of the Invention

The invention aims to solve the technical problems of high temperature rise and low weight of the existing fully enclosed asynchronous traction motor used on low-floor vehicles. To this end, the present invention proposes a fully enclosed asynchronous traction motor for use on a low-floor vehicle.

The technical solutions adopted by the present invention to solve its technical problems are:

A fully enclosed asynchronous traction motor for a low-floor vehicle includes a rotating shaft, a rotor assembly, a stator assembly, a non-drive end cover, and a drive end cover. The rotor is mounted on the shaft, and the ends of the stator are axially mounted on the two ends. It is connected to the non-drive end cover and the drive end cover. The so-called fully enclosed asynchronous traction motor here means that a closed cavity is formed inside the motor. The rotor is assembled in the closed cavity and can be isolated from the outside to ensure the safety of the rotor. Reliable operation; the shaft extends outside the non-transmission end cover to form a shaft extension, a main fan is installed on the shaft extension, the air inlet of the main fan communicates with the outside world, and the shaft is installed with a fully enclosed asynchronous traction The auxiliary fan of the closed chamber of the motor. The main fan and auxiliary fan here may adopt the fan structure commonly used in the field of motors. The non-transmission end cover is provided with an air inlet channel communicating with the air outlet of the main fan. The transmission end cover is provided with an air outlet channel communicating with the outside; the stator assembly includes a stator core, a pressure plate, a tension plate, a transmission end stator pressure ring, and a non-transmission end fixing. Such a structure, the stator core of the structure is exposed to the outside, eliminating the structure of the machine base, and the heat dissipation is better, and the weight is higher; the non-drive end stator pressure ring is fixedly connected to the non-drive end cover, so The drive end stator pressure ring is fixedly connected to the drive end cover, the non-drive end stator pressure ring is provided with a first outer air channel and a first inner air channel isolated from each other, and the stator iron core is provided with a first isolated air channel. Two outer air ducts and a second inner air duct, the drive end stator pressure ring is provided with a third outer air duct and a third inner air duct which are isolated from each other, and the drive end cover is also provided with a separate from the air outlet passage A fourth inner air duct, a fifth inner air duct which penetrates both ends of the axial direction is opened on the rotor core of the rotor assembly, the main fan, the air inlet passage, the first outer air duct, the second outer air duct, the first The three outer air ducts and the air outlet channel are connected in sequence to form a first outer air path, the auxiliary fan, the first inner air duct, the second inner air duct, the third inner air duct, the fourth inner air duct, and the fifth inner wind. The channels communicate in sequence to form a first internal air path. When in use, the wind enters from the inlet of the main fan and exits from the air outlet passage after passing through the first external air path, which is mainly used to cool the stator core; under the action of the auxiliary fan, the wind is formed by the first internal air path A circulating air flow is formed in the circuit, which is mainly used to cool the rotor core and the ends of the stator windings. In addition, there is a second internal air path here. Due to the air gap between the rotor transfer and the stator assembly, the wind can pass through the fifth internal air duct, the closed cavity, and the air gap in sequence under the action of the auxiliary fan. A second air path is formed, and the surface of the outer ring of the rotor core is cooled by the circulating air flow. The main innovation of the present invention is that the present invention removes the machine base and directly exposes the stator core to the outside, which has better heat dissipation and a higher degree of weight reduction. Compared with the 200810079856.7 patent described in the background, the present invention removes The machine base was overcome, and its technical problems that depended on the machine base were overcome. The new inner and outer air duct structures were researched, which can better meet the technical requirements of low-floor vehicles for small motors, high weight, and high heat dissipation. .

The beneficial effect of the present invention is that the present invention provides a fully enclosed asynchronous traction motor for a low-floor vehicle. A first outer air path for cooling the stator core is formed inside the motor, and a rotor core and The first inner air path for cooling the ends of the stator windings and the second inner air path for cooling the outer ring surface of the rotor core, which can achieve high-efficiency cooling of the motor and control the overall temperature rise of the motor to avoid A series of problems such as motor burnout caused by the overall high temperature of the motor; and the structure of the base is omitted, which makes the overall motor lighter, smaller, better in heat dissipation, and more suitable for low-floor vehicles Requirements for the motor.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic diagram of the overall installation structure of the motor of the present invention;

FIG. 2 is a schematic structural diagram of a first external air path of the present invention; FIG.

3 is a schematic structural diagram of a first internal air path and a second internal air path of the present invention;

4 is a schematic cross-sectional structure view of a non-transmission end cover of the present invention;

5 is a schematic perspective structural view of a transmission end cover of the present invention;

FIG. 6 is a perspective structural schematic view of a driving end stator pressing ring according to the present invention; FIG.

7 is a schematic perspective view of a non-drive end stator pressing ring according to the present invention;

8 is a schematic structural diagram of a stator core punch and a rotor core punch of the present invention.

detailed description

1 to 7, a fully enclosed asynchronous traction motor for a low-floor vehicle includes a rotating shaft 1, a rotor assembly, a stator assembly, a non-drive end cover 3 and a drive end cover 11, a coupling 5 and The sealing plate 28 is installed between the transmission end cover 11 and the coupling 5. The rotor is assembled on the rotating shaft 1. The rotor assembly includes a rotor core 6 and a rotor pressing plate 7 at both ends of the rotor core 6. The stator assembly shaft The two ends are connected to the non-drive end cover 3 and the drive end cover 11 respectively. The coupling 5 is installed at the drive end of the rotating shaft 1 for connection with the gear box. The sealing plate 28 covers the drive end cover 11 and the coupling. The annular area between the shaft joints 5, the non-drive end cover 3, the drive end cover 11, the stator assembly, the rotating shaft 1, the coupling 5 and the sealing plate 28 together form a closed cavity, so-called fully enclosed here The motor refers to the closed cavity formed inside the motor. The rotor is assembled in the closed cavity and can be isolated from the outside to ensure the safe and reliable operation of the rotor. The rotating shaft 1 extends beyond the non-transmission end cover 3 to form a shaft. The main fan 2 is mounted on the shaft extension. The air outlet is in communication with the outside. The rotating shaft 1 is equipped with an auxiliary fan 4 located in the closed cavity. The main fan 2 and the auxiliary fan 4 here may adopt a fan structure commonly used in the field of motors. The non-drive end cover 3 is provided with an air inlet passage 12 communicating with the air outlet of the main fan 2, and the transmission end cover 11 is provided with an air outlet passage 19 communicating with the outside; the stator assembly includes a stator iron core 8, a pressure plate 26, The pulling plate 27, the driving-end stator pressing ring 9 and the non-driving-end stator pressing ring 10 have such a structure that the stator core 8 is exposed to the outside, eliminating the structure of the machine base, and having better heat dissipation and lighter weight; The non-drive end stator pressure ring 10 is fixedly connected to the non-drive end cover 3, the drive end stator pressure ring 9 is fixedly connected to the drive end cover 11, and the non-drive end stator pressure ring 10 is provided with first and second isolated ends. An outer air duct 13 and a first inner air duct 14, the stator iron core 8 is provided with a second outer air duct 15 and a second inner air duct 16 which are separated from each other, and the transmission end stator pressure ring 9 is provided with isolation from each other The third outer air duct 17 and the third inner air duct 18, the transmission end cover 11 is also A fourth inner air duct 20 is provided, which is isolated from the air outlet channel 19, and a fifth inner air duct 21 is formed on the rotor core of the rotor assembly and penetrates both ends in the axial direction. The main fan 2, the air inlet channel 12, The first outer air duct 13, the second outer air duct 15, the third outer air duct 17, and the air outlet channel 19 are sequentially connected to form a first outer air path. The auxiliary fan 4, the first inner air duct 14, and the second inner air duct. The air duct 16, the third inner air duct 18, the fourth inner air duct 20, and the fifth inner air duct 21 are sequentially connected to form a first inner air path. In use, the wind enters from the inlet of the main fan 2 and exits from the air outlet passage 19 after passing through the first external air path, which is mainly used to cool the stator core 8; under the action of the auxiliary fan 4, the wind is in the first inner A circulating air flow is formed in a loop formed by the air path, and is mainly used for cooling the rotor core and the end 25 of the stator winding. In addition, there is a second internal air path here. Due to the air gap between the rotor transfer and the stator assembly, the wind can pass through the fifth internal air duct 21, the closed cavity and The air gap forms a second air path, and the surface of the outer ring of the rotor core is cooled by the circulating air current. The main innovation of the present invention is that the present invention removes the machine base and directly exposes the stator core 8 to the outside, which has better heat dissipation and higher degree of lightweighting. Compared with the 200810079856.7 patent described in the background, the present invention Removed the machine base, overcome its technical problems that depend on the machine base, researched the new inner air duct and outer air duct structure, and can better meet the low-floor car's technology of small size, light weight and high heat dissipation for the motor Claim.

As a further improvement of the above technical solution, the stator core 8 is formed by alternately laminating two kinds of punches with different diameters to form a second outer air path 24 on the surface of the outer ring. In this way, a plurality of natural air ducts will be formed on the outer ring of the stator core 8, and natural wind can flow through the natural air ducts to dissipate heat from the surface of the stator core 8. The natural wind path here is the second external wind path 24. Further, the two punching pieces are laminated into a unit with 15-25 pieces as a group, and then the units of the two punching pieces are alternately laminated to form the stator core 8. Specifically, 15 or 20 or 25 punching pieces can be used. Form a unit, which can ensure the width of the natural air duct and further improve heat dissipation efficiency.

Preferably, the ratio of the number of punched slots of the stator core 8 to the number of punched slots of the rotor core 6 is 36:28. This slot number ratio is the best slot number ratio obtained after a large number of experiments. Compared with the existing slot number ratio of 36:46, the comparative test is as follows: the frequency is 68Hz, the voltage is 530V, the power is 120kW, and the speed is selected. For the two motors at 2018r / min, the motor test temperature rise of the 36:28 slot number ratio reached a steady state of 168K, but at the same time, the test temperature rise of the 36:46 slot number motor has reached 200K, and the test temperature The rise has not yet reached a steady state, and there is still an upward trend. Therefore, the 36:28 slot number structure adopted by the present invention can improve the heat dissipation efficiency of the motor and better control the temperature rise of the motor compared to the existing structure.

Preferably, two sets of first outer air ducts 13 and two sets of first inner air ducts 14 are uniformly distributed in the circumferential direction of the non-drive end stator pressing ring 10, and each set of first outer air ducts 13 includes at least two first outer air ducts. 13. Each group of first inner air ducts 14 includes at least two first inner air ducts 14. In specific implementation, the non-drive end stator pressing ring 10 is set to a square shape, and the two sets of first outer air channels 13 are symmetrically arranged on a pair of opposite sides of a square shape, which also meets the condition of uniform distribution in the circumferential direction.

Further, the air inlet passage 12 and the fan blade adopt an arc design, which can effectively reduce the ventilation resistance, increase the overall smoothness of the air path, and improve the overall ventilation and heat dissipation efficiency of the motor. The arc design is used here mainly to reduce the resistance, so those skilled in the art should know how to design the arc, that is, to design the length direction of the air inlet channel 12 to be arc-shaped, and to design the surface of the fan blades to be arc-shaped.

As a preferred fixing manner of the rotating shaft 1, a bearing housing 23 is fixed to the inner ring of the non-transmission end cover 3, a bearing 22 is mounted on the bearing housing 23, and one end of the rotating shaft 1 is supported on the bearing 22. This is more in line with the lightweight requirements of low-floor motors.

The above specific structure and size data are specific descriptions of the preferred embodiments of the present invention, but the invention creation is not limited to the embodiments, and those skilled in the art can also make without departing from the spirit of the present invention. Various equivalent deformations or substitutions are included in the scope defined by the claims of the present application.

Claims

A fully enclosed asynchronous traction motor for a low-floor vehicle, comprising a rotating shaft (1), a rotor assembly, a stator assembly, a non-drive end cover (3), and a drive end cover (11). The non-drive end cover (3) is extended to form a shaft extension. A main fan (2) is installed on the shaft extension. The air inlet of the main fan (2) communicates with the outside world. The rotation shaft (1) is installed on the shaft extension. There is an auxiliary fan (4) located in the closed cavity of the fully enclosed asynchronous motor, and the non-transmission end cover (3) is provided with an air inlet channel (12) communicating with the air outlet of the main fan (2). The transmission end cover (11) is provided with an air outlet channel (19) communicating with the outside, and is characterized in that the stator assembly includes a stator core (8), a pressure plate (26), a pull plate (27), and a transmission end stator. Pressure ring (9) and non-drive end stator pressure ring (10), the non-drive end stator pressure ring (10) is fixedly connected to the non-drive end cover (3), and the drive end stator pressure ring (9) is connected with The transmission end cover (11) is fixedly connected, the non-drive end stator pressure ring (10) is provided with a first outer air duct (13) and a first inner air duct (14), which are isolated from each other, and the stator core ( 8) The second The outer air duct (15) and the second inner air duct (16), the drive end stator pressure ring (9) is provided with a third outer air duct (17) and a third inner air duct (18), which are isolated from each other. The transmission end cover (11) is also provided with a fourth inner air channel (20) which is isolated from the air outlet channel (19). The rotor core of the rotor assembly is provided with a fifth inner air channel which penetrates both ends in the axial direction. (21), the main fan (2), an air inlet channel (12), a first external air channel (13), a second external air channel (15), a third external air channel (17), and an air outlet channel ( 19) Connected in order to form a first outer air path, the auxiliary fan (4), the first inner air duct (14), the second inner air duct (16), the third inner air duct (18), and the fourth inner wind. The channel (20) and the fifth internal air channel (21) are sequentially connected to form a first internal air channel.
The fully enclosed asynchronous traction motor for use on a low-floor vehicle according to claim 1, characterized in that the stator core (8) is formed by alternately laminating two punches of different diameters to the outside. The surface of the ring forms a second outer air path (24).
The fully enclosed asynchronous traction motor for a low-floor vehicle according to claim 2, characterized in that: both punching pieces are laminated into a unit with a group of 15-25 pieces, and then two punching pieces The lamination units are alternately laminated to form a stator core (8).
The fully enclosed asynchronous traction motor for a low-floor vehicle according to claim 1, characterized in that the ratio of the number of punched slots of the stator core (8) to the number of punched slots of the rotor core It's 36:28.
The fully enclosed asynchronous traction motor for use on a low-floor vehicle according to any one of claims 1 to 4, characterized in that the non-drive end stator pressure ring (10) is uniformly distributed with two sets of first external winds in the circumferential direction. Channel (13) and two sets of first inner air duct (14), each group of first outer air duct (13) includes at least two first outer air ducts (13), each group of first inner air duct (14) includes At least two first inner air ducts (14).
The fully enclosed asynchronous traction motor for a low-floor vehicle according to claim 5, characterized in that the air inlet passage (12) and the fan blades adopt a circular arc design to reduce wind resistance.
The fully enclosed asynchronous traction motor for a low-floor vehicle according to claim 6, characterized in that: a bearing seat (23) is fixed to an inner ring of the non-drive end cover (3), and the bearing seat A bearing (22) is mounted on (23), and one end of the rotating shaft (1) is supported on the bearing (22).