JP2007282341A - Motor with cooling mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor equipped with a cooling mechanism high in cooling capacity under heavy load. <P>SOLUTION: An end ring 33 of a motor rotor 3 that constructs a torque generating mechanism of a motor unit 1 together with a motor stator, is provided with a groove 33a, and an end ring 34 is provided with a groove 34a. A balance ring 71 that is fixed on a shaft 2 and is used for balance correction, is provided with a groove 71a, and a balance ring 72 is provided with a groove 72a. The inner circumferential surface of a housing 6 is provided with a gas passage 6d. Internal gas is circulated through an air gap 6a and the gas passage 6d by the rotation of the shaft 2 to facilitate heat exchange between the inside and the outside of the housing 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a built-in motor for blowing air such as a turbo fan or a turbo blower, in which a motor mechanism portion is housed in a housing and incorporated in each device.

Conventionally, in a device using a built-in motor, the motor main part is housed in a housing 101 as shown in FIG. 4, and both sides of a shaft (main shaft) 103 to which a motor rotor (rotor) 102 is fixed are disposed in the housing 101. The shaft 104 is supported by a bearing 104 fitted to the housing 101, and both shaft ends project outside the housing 101 to fix a necessary impeller (not shown), and the outer peripheral surface of the motor stator (stator) 105 is fixed to the inner peripheral surface of the housing 101. Are integrally connected by press fitting or the like. When the motor is an induction motor, about 15% of the supplied power is consumed by the motor itself and the housing 101 is almost sealed, so that the temperatures of the motor rotor 102, the motor stator 105, and the shaft 103 are increased. Reduces the reliability of the motor. Therefore, although the outer wall of the housing 101 is not shown, it is blown by a fan, or a coolant such as gas or water is separately flowed into the housing 101 to cool it from the outer periphery of the motor stator 105, or as shown in FIG. The end ring 107 is provided with a rotor fin 106 to dissipate heat and stir the air in the housing 101 (see, for example, Patent Document 1).
JP-A-11-75345

Normally, the end rings 107 at both ends of the motor rotor 102 are made of aluminum die cast or the like, but there is no means for directly cooling the motor rotor 102. Reliability has been affected by the temperature rise of the end ring 107 and the generation of stress in the end ring 107 due to the centrifugal force applied to the motor rotor 102 under high speed operation. In addition, in the case of air agitation using the rotor fin 106, there is a problem that a sufficient cooling effect cannot be obtained especially by the influence of reliability due to the centrifugal force of the fin portion and by not actively flowing gas into the air gap. It was. For this reason, it is necessary to take measures such as reducing the output, increasing the motor size, improving the safety such as increasing the cooling capacity of the motor stator 105, or changing the aluminum material of the end ring 107 to a higher strength material. Further, it is difficult to directly cool the motor stator 105, and there has been a concern about a decrease in motor efficiency accompanying an increase in motor resistance due to a temperature increase of the stator coil in the motor stator 105.
This invention is made | formed in view of such a situation, Comprising: It aims at providing the motor provided with the cooling mechanism with a large cooling capability in the state where a motor load is large.

In order to achieve the above-mentioned object, the present invention is directed to a shaft in which a motor rotor having end rings at both ends is fixed, a bearing that supports both ends of the shaft, and magnetic induction between the motor rotor and a rotational force applied to the shaft. In a motor comprising a housing in which a motor stator for generating a motor is installed, a groove inclined with respect to the shaft core is formed in the outer peripheral portion of the end ring, and a gas flow is generated in the motor by the groove. did.
In addition, the present invention provides a shaft having a balance ring fixed to correct unbalance during rotation of a rotating body composed of at least a motor rotor and a shaft, a bearing that supports both ends of the shaft, and the motor rotation. In a motor comprising a housing having a motor stator for generating rotational force on the shaft by magnetic induction with the body, a groove inclined with respect to the shaft core is formed in the outer peripheral portion of the balance ring. A gas flow was generated inside the motor.
Further, according to the present invention, a gas flow groove is formed in the inner wall portion of the housing, and a gas passage is provided between the outer peripheral portion of the motor stator and the inner wall portion of the housing.

  In the motor according to the present invention, the internal gas in the housing can be circulated through the gas passage formed between the motor rotor and the motor stator and between the motor stator and the housing, so that the cooling capacity is improved and the temperature rises. Can be reduced. Accordingly, the influence of the deterioration of the strength of the end ring of the motor rotor is reduced and the reliability is improved, and it becomes possible to use in a harsher environment and to be downsized.

  The best mode for carrying out the motor with a cooling mechanism according to the present invention is such that a gas passage is provided between a gas passage formed of a plurality of grooves on the outer periphery of the end ring and the balance ring, a motor stator that forms a rotating magnetic field, and a housing. The optimum number of grooves varies depending on the number of rotations and load of the motor, but is generally 5 to 10, and the shape of the groove is a gas flow that flows from the groove to the motor rotor and from the motor rotor to the groove. It is desirable that the groove bottom and the surface of the motor rotor are substantially flush with each other so that the flow can be smoothly performed.

  Hereinafter, an embodiment in which the present invention is applied to an induction motor will be described with reference to the drawings. FIG. 1 is a side view showing a configuration of a motor provided with the cooling mechanism in a partial cross section, FIG. 2 is a cross-sectional view taken along line AA of the end ring according to the embodiment (FIG. 1), and FIG. .

  As shown in FIG. 1, a motor 1 having a cooling mechanism according to the present invention (hereinafter referred to as a motor unit) 1 includes a motor rotor 3 fixed to a shaft 2 and a bearing 41 that supports the vicinity of both ends of the shaft 2. , 42 and the motor rotor 3 are composed of a housing 6 in which a motor stator 5 for generating a rotational force on the shaft 2 by electromagnetic induction is fixedly provided with the motor rotor 3 and a constant air gap 6a. Yes.

  The motor rotor 3 includes a rotor core 31 formed by laminating disc-shaped silicon steel plates, a plurality of holes that are penetrated at regular intervals in the vicinity of the outer periphery thereof, and a plurality of aluminum members that are poured into both ends of the rotor core 31. The rotor bar 32 and end rings 33 and 34 for short-circuiting both ends thereof. As shown in the sectional view of FIG. 2, the end ring 33 is processed with a plurality of grooves 33 a in a direction inclined with respect to the axial direction of the shaft 2, and the end ring 34 is processed with a plurality of grooves 34 a. The motor stator 5 includes a stator core 51 formed by laminating silicon steel plates having a ring plate shape and through holes provided at regular intervals, and a stator coil 52 inserted into the through holes. .

  Further, when it is necessary to perform balance correction in order to remove the whirling vibration caused by the centrifugal force generated at the time of high speed rotation due to the eccentricity of the shaft 2, the large-diameter balance rings 71 and 72 are fixed to the shaft 2, The side or outer peripheral surface is corrected during manufacturing by grinding or the like. The balance ring 71 has a plurality of grooves 71a in the direction inclined with respect to the axis of the shaft 2 similar to the groove 33a, and the balance ring 72 has grooves 72a similar to the grooves 34a. The shapes of the grooves 33a, 34a, 71a, 72a are not limited to the U-shape shown in FIGS. 2 and 3, and the side surfaces may be inclined. The number of grooves varies depending on the number of rotations of the motor and the load, but generally 5 to 10 grooves are formed.

  When the motor unit 1 is supplied with a rated commercial power supply or a high-frequency power supply by an inverter power supply, a current flows through the stator coil 52 to generate an induced rotating magnetic field. An electromotive force is generated in the rotor bar 32 by this induced rotating magnetic field, and an eddy current flows through the end rings 33 and 34. A rotational force proportional to the current and the rotating magnetic field is generated in the motor rotor 3 and the shaft 2 rotates in the direction of the arrow. About 15% of the electric power supplied to the motor unit 1 is consumed as copper loss and iron loss in the motor rotor 3 and the motor stator 5, and the internal temperature of the motor rotor 3 and the motor stator 5 rises due to heat generation. .

  As the shaft 2 rotates, the gas around the end ring 33 and the balance ring 71 swirls, and the gas in the left space 6b flows in the direction of the arrow along the grooves 33a and 71a, and the motor rotor 3 and the motor stator. 5 is introduced into the air gap 6a. Further, the peripheral gas of the end ring 34 and the balance ring 72 is swirled and the peripheral gas flows rightward along the grooves 34a and 72a, whereby the gas in the air gap 6a is sucked out. For this reason, the gas pressure in the left space 6b decreases, the gas pressure in the right space 6c increases, and external gas flows into the left space 6b through the vent holes of the bearings 41, 42 and the like. Gas flows out. This internal gas flow promotes heat exchange between the housing 6 itself and the outside and heat exchange between the inside and outside gas, and the motor increases due to the increase in the contact gas flow rate accompanying the increase in the surface area of the end rings 33 and 34 and the balance rings 71 and 72. Temperature rises of the rotor 3 and the motor stator 5 are suppressed. Further, in the air gap 6a, the gas in the air gap 6a also generates heat due to windage damage. However, the gas in the air gap 6a is sucked out, so that the temperature of the gas becomes high, and the motor rotor 3 and the motor stator 5 associated therewith. It is also possible to suppress the temperature rise.

  Further, in the motor unit 1 of the present invention, the inner peripheral wall of the housing 6 is processed as shown in FIG. 1, and a gas passage 6 d is provided between the outer peripheral wall of the motor stator 5. The gas passage 6d is used as a gas passage for circulating the gas sucked from the air gap 6a by the end ring 34 and the balance ring 72 through the inner wall of the housing 6 to the left space 6b. As a result, the hot gas in the air gap 6a undergoes heat exchange with the outside through the housing 6 while passing through the gas passage 6d, thereby further improving the cooling capacity. This method also works effectively when it is necessary to block the internal space of the motor unit 1 from the external space as much as possible.

  The present invention is not limited to the above-described embodiments, and can be applied to a motor having a cylindrical motor rotor and a motor stator such as a DC motor instead of the induction motor.

  The present invention is used for a motor in which the fluidity of the internal gas in the housing is low and the internal temperature rise is large under a high load.

It is a block diagram of the motor unit by this invention. It is sectional drawing of the end ring concerning an Example. It is a perspective view of the rotor core concerning an Example. It is a figure which shows the structural example of the conventional motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor unit 2 Shaft 3 Motor rotor 31 Rotor core 32 Rotor bar 33 End ring 33a Groove 34 End ring 34a Groove 41 Bearing 42 Bearing 5 Motor stator 51 Stator core 52 Stator coil 6 Housing 6a Air gap 6b Left space 6c Right space 6d Gas passage 71 Balance ring 71a Groove 72 Balance ring 72a Groove 101 Housing 102 Motor rotor 103 Shaft 104 Bearing 105 Motor stator 106 Rotor fin 107 End ring

Claims (3)

A motor stator having a motor rotor having end rings at both ends, a motor stator that generates rotational force on the shaft by magnetic induction between the motor rotor and a bearing that supports both ends of the shaft are provided internally. A motor having a cooling mechanism, wherein a groove inclined with respect to an axis is formed in an outer peripheral portion of the end ring, and a gas flow is generated inside the motor by the groove. Magnetic induction between a shaft having a balance ring fixed to correct unbalance during rotation of a rotating body composed of at least a motor rotor and a shaft, a bearing bearing both ends of the shaft, and the motor rotor In the motor comprising a housing in which a motor stator for generating rotational force is generated by the shaft, a groove inclined with respect to the shaft core is formed in the outer peripheral portion of the balance ring, and the gas flows into the motor by the groove. A motor provided with a cooling mechanism characterized by 3. A motor provided with a cooling mechanism according to claim 1, wherein a groove for gas flow is formed in an inner wall portion of the housing, and a gas passage is provided between the outer periphery of the motor stator and the inner wall portion of the housing.

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