CN210536441U - Double-wind-path structure capable of effectively reducing temperature rise of high-power wide-rotating-speed variable frequency motor - Google Patents

Abstract

The utility model discloses a can effectively reduce two wind path structures of high-power wide rotational speed inverter motor temperature rise, solve current two air-cooled cooling wind path and can not effectively reduce the problem of high-power wide rotational speed water cooled machine temperature rise. A centrifugal fan arranged on a motor rotor is refitted into a cooler, so that the wind speed and the wind quantity of circulating cooling wind are not influenced by the rotating speed of the motor; the method of drilling a radial vent hole on a straight-line section lead of the rotor winding is abandoned, and the radial vent hole is opened on the side wall of the rotor winding embedded groove; the hot air blown through the end part of the stator winding is directly led into the hot air chamber, and the cooling air bypassing the end part of the stator is led into the cold air chamber through the air guide channel, so that the air entering the cold air chamber is prevented from being heated and heated by the end part of the stator winding. The utility model discloses wind path scientific and reasonable's setting has guaranteed that the temperature rise of high-power wide rotational speed inverter motor all accords with the designing requirement under various operating modes.

Description

Double-wind-path structure capable of effectively reducing temperature rise of high-power wide-rotating-speed variable frequency motor

Technical Field

The invention relates to a cooling air path in a water-cooled motor, in particular to a double-air-path air cooling structure in a high-power wide-rotating-speed variable-frequency water-cooled motor.

Background

For a high-power wide-rotating-speed water-cooled variable-frequency synchronous motor, the capacity of continuous load operation in a wide rotating speed range is firstly required, and the motor is characterized in that: the span of the rotating speed range is wide, some rotating speed ranges are (15-2400) rpm, the power of the motor is large, and the power can reach more than 10 megawatts; because the rotating speed range is wide, the highest rotating speed is high, and the rotating speed range is limited by the mechanical property of a motor manufacturing material, the rotor core of the motor cannot be formed by laminating silicon steel sheets, and the rotating shaft and the rotor core are integrally forged in a general forging mode; because the centrifugal force at the end of the rotor winding is proportional to the square of the rotating speed of the rotor and proportional to the radius of the rotor, the larger the outer diameter of the rotor is, the larger the centrifugal force which the retaining ring on the rotor needs to bear, and the mechanical properties which the retaining ring material can bear are limited, therefore, the diameter of the rotor of the high-speed motor cannot be designed to be too large, but in order to meet the requirement of high power, the axial length of the whole motor can only be designed to be longer, a centrifugal fan is arranged on the rotating shaft to form a circulating cooling air path between the inside of the motor and a cooler, the heat in the motor is brought into the cooler by the circulating cooling air to exchange heat with cooling water to reduce the temperature rise inside the motor, and the motor with a longer rotating shaft generally adopts a double-air-path cooling structure, namely, that is, a circulating cooling air path is arranged between the driving end (AS end) of the motor, another circulating cooling air path is arranged between the non-driving end (BS end) of the motor and the middle part of the stator and the rotor so as to achieve better cooling effect; in addition, in order to effectively reduce the high temperature rise of the rotor winding of the high-power motor, the prior art is that radial vent holes are drilled on the linear side of the rotor winding lead, so that cooling air passes through the vent holes, and a better effect of cooling the rotor winding is achieved; for the motor, the conventional design method is that two ends of a stator are respectively provided with a hot air chamber, the middle part of the stator between the two hot air chambers is provided with a cold air chamber, and cold air after water cooling enters end cover chambers at two ends of the motor and is divided into two paths to complete the cooling task of the motor: one path of cold air is blown through the end part of the stator winding and then is introduced into a cold air chamber in the middle of the motor through an air guide channel to cool the middle section of the iron core, then enters into radial ventilation channels at two ends of the stator iron core through an air gap between the stator and the rotor to cool two ends of the stator iron core, air blown out from the radial ventilation channels of the stator iron core enters into a hot air chamber and then enters into a cooling chamber again, hot air is cooled through heat exchange between the hot air and cooling water, the cooled air enters into end cover chambers at two ends of the motor again, and the circulation is carried out, so that the cooling of the motor is realized; the other path of cold air enters a ventilation auxiliary groove at the bottom of a rotor winding groove after blowing the end part of the rotor winding, then enters a stator air gap and a rotor air gap after blowing a radial ventilation channel arranged on a rotor winding lead, then enters the radial ventilation channels at two ends of a stator iron core through the stator air gap and the rotor air gap, and finally enters a cooler through a hot air chamber to carry out heat exchange between hot air and cooling water; the existing air path cooling structure has the following three defects: (1) when the motor runs at a low rotating speed, the rotating speed of a centrifugal fan on a rotating shaft of the motor is very low, so that the circulating speed and the flow of circulating cooling air are too low, and the temperature rise of the motor cannot be effectively reduced; (2) the cooling air introduced into the cold air chamber in the middle of the motor through the air guide duct firstly blows the cooling air which passes through the end part of the stator winding and is heated by the end part of the stator winding, and the cooling air is used for cooling the middle part of the stator iron core and the two ends of the iron core, so that the cooling effect is greatly reduced; (3) the mode of opening radial ventilation hole on rotor winding wire straight line edge can cause the local cross-section of winding wire to narrow down, directly leads to the magnetic density and the electric density of this department to rise, causes the local temperature of winding to rise on the contrary easily, simultaneously, still can increase rotor winding's the preparation degree of difficulty, the insulating processing degree of difficulty and rotor winding's rule degree of difficulty.

Disclosure of Invention

The invention provides a double-air-path structure capable of effectively reducing the temperature rise of a high-power wide-rotating-speed variable frequency motor, and solves the technical problem that the temperature rise of a high-power wide-rotating-speed water-cooled motor cannot be effectively reduced by the existing double-air-cooled cooling air path.

The invention solves the technical problems by the following technical scheme:

the general concept of the invention is: the centrifugal fan arranged on the motor rotor is changed into a centrifugal fan arranged in the cooling chamber, so that the wind speed and the flow of the circulating cooling wind are not influenced by the rotating speed of the motor; the method of drilling a radial vent hole on a straight-line section lead of the rotor winding is abandoned, and the radial vent hole is opened on the side wall of the rotor winding embedded groove; the hot air blown through the end part of the stator winding is directly led into the hot air chamber, and the cooling air bypassing the end part of the stator is led into the cold air chamber through the air guide channel, so that the air entering the cold air chamber is prevented from being heated and heated by the end part of the stator winding.

A double-air-path structure capable of effectively reducing the temperature rise of a high-power wide-rotating-speed variable frequency motor comprises a water cooling chamber, a motor AS end cover chamber, a motor BS end cover chamber and a rotor winding embedded groove, wherein an AS end stator winding end part and an AS end rotor winding end part are arranged in the motor AS end cover chamber, an AS side hot air chamber and a BS side hot air chamber are respectively arranged on a motor stator base, a cold air chamber is arranged between the AS side hot air chamber and the BS side hot air chamber, an AS end annular end plate is arranged between the AS side hot air chamber and the motor AS end cover chamber, a rotor winding ventilation groove bottom auxiliary groove is communicated with the groove bottom of the rotor winding embedded groove, the rotor winding groove bottom ventilation auxiliary groove is communicated with the motor AS end cover chamber, an inner side ventilation opening communicated with the AS side hot air chamber is arranged on the AS end annular end plate close to the AS end stator winding end part, and an outer side air inlet is arranged on the AS end annular end plate far, the outer side air inducing port is connected with one end of an air inducing pipe, and the other end of the air inducing pipe is communicated with the cold air chamber; a motor AS end cooling circulating air driving centrifugal fan and a motor BS end cooling circulating air driving centrifugal fan are respectively arranged in the water cooling chamber; the inner side wall of the slot of the rotor winding embedded slot is provided with a semi-cylindrical radial ventilation duct, the lower end of the semi-cylindrical radial ventilation duct is communicated with a ventilation auxiliary slot at the bottom of the rotor winding slot, and the upper end of the semi-cylindrical radial ventilation duct is communicated with the gap between the stator and the rotor.

The inner side ventilation openings on the AS end annular end plate are arranged on the same circumference at equal intervals in radian; and semi-cylindrical radial ventilation ducts are arranged on two side walls in the slot of the rotor winding embedded slot.

The invention divides the cooling air to flow, ensures the cooling effect of the cooling air on the stator and the rotor, and the radial ventilation holes of the rotor, which are communicated with the ventilation auxiliary grooves at the bottom of the winding groove of the rotor, are arranged on the tooth parts at the two sides of the winding groove, thereby achieving the purpose of cooling the rotor winding on the premise of not damaging the magnetic density, the electric density and the insulation of the winding.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a diagram showing the fitting relationship between the rotor winding embedded slots 19 and the rotor winding slot bottom ventilation auxiliary slots 18 according to the present invention.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings:

a double-air-path structure capable of effectively reducing the temperature rise of a high-power wide-rotating-speed variable frequency motor comprises a water cooling chamber 1, a motor AS end cover chamber 4, a motor BS end cover chamber 5 and a rotor winding embedded groove 19, wherein an AS end stator winding end part 6 and an AS end rotor winding end part 7 are arranged in the motor AS end cover chamber 4, an AS side hot air chamber 13 and a BS side hot air chamber 14 are respectively arranged on a motor stator base, a cold air chamber 12 is arranged between the AS side hot air chamber 13 and the BS side hot air chamber 14, an AS end annular end plate 8 is arranged between the AS side hot air chamber 13 and the motor AS end cover chamber 4, a rotor winding groove bottom ventilation auxiliary groove 18 is communicated with the rotor winding groove bottom 18, the rotor winding groove bottom ventilation auxiliary groove 18 is communicated with the motor AS end cover chamber 4, an inner side ventilation opening 9 communicated with the AS side hot air chamber 13 is arranged on the AS end annular end plate 8 and close to the AS end stator winding end part 6, an outer air induction port 10 is arranged on the AS end annular end plate 8 far away from the AS end stator winding end part 6, the outer air induction port 10 is connected with one end of an air induction pipe 11, and the other end of the air induction pipe 11 is communicated with a cold air chamber 12; a motor AS end cooling circulating air driving centrifugal fan 2 and a motor BS end cooling circulating air driving centrifugal fan 3 are respectively arranged in the water cooling chamber 1; a semi-cylindrical radial ventilation duct 20 is arranged on the inner side wall of the rotor winding embedded groove 19, the lower end of the semi-cylindrical radial ventilation duct 20 is communicated with a ventilation auxiliary groove 18 at the bottom of the rotor winding groove, and the upper end of the semi-cylindrical radial ventilation duct 20 is communicated with the stator-rotor gap 16; a middle radial air duct 15 and an edge radial air duct 17 are provided on the stator core, the middle radial air duct 15 is communicated with the cold air chamber 12, and the edge radial air duct 17 is communicated with the AS-side hot air chamber 13.

The inner ventilation openings 9 on the AS end annular end plate 8 are arranged on the same circumference at equal intervals in radian; the two side walls in the rotor winding embedded groove 19 are provided with semi-cylindrical radial ventilation ducts 20; the cooling air passage provided in motor BS end cover chamber 5 is identical to that provided in motor AS end cover chamber 4.

The cooling air circulation process of the present invention is described below by taking an AS-side cooling circulation air path of the motor AS an example, after the hot air absorbed the heat of the motor in the motor water cooling chamber 1 is sucked into the cooler 21 by the AS-side cooling circulation air driving centrifugal fan 2, heat exchange is performed between the hot air and the cooling water, the cooled cold air after heat exchange is blown into the AS-side end cover chamber 4 of the motor by the AS-side cooling circulation air driving centrifugal fan 2, and the air is divided into three paths: the first path of cooling air is heated and heated after blowing through the AS end stator winding end part 6, the heated and heated air directly enters the AS side hot air chamber 13 through the inner side ventilation opening 9, and is sucked back to the water cooling chamber 1 for cooling by the motor AS end cooling circulating air driving centrifugal fan 2; after bypassing the AS end stator winding end part 6, the second path of cooling air is introduced into a cold air chamber 12 through an air induction port 10 and an air induction pipe 11, then enters a stator and rotor air gap 16 through a stator core middle radial ventilation channel 15, then enters an AS side thermal air chamber 13 through a stator core side radial ventilation channel 17, and is cooled by a motor AS end cooling circulating air driving centrifugal fan 2 to suck back into a water cooling chamber 1 for cooling; the third path of cooling air blows through the AS end rotor winding end part 7 and then enters into a rotor winding groove bottom ventilation auxiliary groove 18, then enters into a stator and rotor air gap 16 after carrying out direct contact type cooling on the rotor winding through a semi-cylindrical radial ventilation channel 20, then enters into an AS side heat air chamber 13 through a stator iron core side radial ventilation channel 17, and is sucked back into the water cooling chamber 1 by the motor AS end cooling circulating air driving centrifugal fan 2 for cooling; the air path is scientifically and reasonably arranged, and the temperature rise of the high-power wide-rotating-speed variable frequency motor is ensured to meet the design requirements under various working conditions.

Claims (2)

1. A double-air-path structure capable of effectively reducing the temperature rise of a high-power wide-rotating-speed variable frequency motor comprises a water cooling chamber (1), a motor AS end cover chamber (4), a motor BS end cover chamber (5) and a rotor winding embedded groove (19), wherein an AS end stator winding end part (6) and an AS end rotor winding end part (7) are arranged in the motor AS end cover chamber (4), an AS side hot air chamber (13) and a BS side hot air chamber (14) are respectively arranged on a motor stator base, a cold air chamber (12) is arranged between the AS side hot air chamber (13) and the BS side hot air chamber (14), an AS end annular end plate (8) is arranged between the AS side hot air chamber (13) and the motor AS end cover chamber (4), a rotor winding groove bottom ventilation auxiliary groove (18) is communicated with the groove bottom of the rotor winding groove (19), and the rotor winding groove bottom ventilation auxiliary groove (18) is communicated with the motor AS end cover chamber (4), the novel air-conditioning system is characterized in that an inner side vent (9) communicated with an AS side hot air chamber (13) is arranged on the AS end annular end plate (8) close to the AS end stator winding end part (6), an outer side air-inducing port (10) is arranged on the AS end annular end plate (8) far away from the AS end stator winding end part (6), the outer side air-inducing port (10) is connected with one end of an air-inducing pipe (11), and the other end of the air-inducing pipe (11) is communicated with a cold air chamber (12); a motor AS end cooling circulating air driving centrifugal fan (2) and a motor BS end cooling circulating air driving centrifugal fan (3) are respectively arranged in the water cooling chamber (1); a semi-cylindrical radial ventilation duct (20) is arranged on the inner side wall of the rotor winding embedded groove (19), the lower end of the semi-cylindrical radial ventilation duct (20) is communicated with a ventilation auxiliary groove (18) at the bottom of the rotor winding groove, and the upper end of the semi-cylindrical radial ventilation duct (20) is communicated with a stator-rotor gap (16).

2. The double-wind path structure capable of effectively reducing the temperature rise of the high-power wide-rotating-speed variable frequency motor according to claim 1, wherein the inner ventilation openings (9) on the AS-end annular end plate (8) are arranged on the same circumference at equal intervals in radian; and semi-cylindrical radial ventilation ducts (20) are arranged on two side walls in the rotor winding embedded groove (19).

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