JP5898976B2 - Impeller system with axial gap rotor - Google Patents

Description

  The present invention relates to a system having an impeller such as an electric pump, a water turbine generator, and an air-conditioning fan configured integrally with a motor or generator having an axial gap rotor having a gap in the axial direction.

  In recent years, the necessity of energy saving has been regarded as important in industrial equipment, home appliances, automobile parts, and the like. Currently, more than half of the amount of power used in the country is consumed by driving the rotating electrical machine. Among them, in applications such as electrification, system applications having impellers such as electrically driven pumps and blower fans account for more than 70%. In power generation applications, a system using an impeller such as a water turbine generator is used.

  A general pump driven electrically has a structure in which a motor and a pump unit are coupled by a shaft and the motor is used as a drive source. In this case, since a coupling component such as a shaft joint must be formed in the axial direction, there is a problem in that the axial dimension becomes long. In order to shorten the dimension in the axial direction, a configuration such as a pump integrated type (JOVD type) in which a motor shaft is directly connected to an impeller has been commercialized. However, since the pump unit is filled with liquid such as water, the pump chamber in which the impeller rotates needs to be sealed so that the liquid does not leak outside. Even the pump integrated type has a structure in which this sealing is performed in the space between the pump chamber and the motor. As a structure that seals so that liquid does not leak out, a structure in which an O-ring of rubber-like member or an oil seal is arranged is adopted. However, a structure that seals through a rotating body such as a shaft requires regular maintenance. It has the disadvantage of becoming necessary. Therefore, Patent Documents 1 and 2 propose a structure in which the pump chamber and the motor are integrated, and the stator electric part of the motor and the pump chamber filled with the liquid are separated by a partition wall. By providing a partition made of a non-magnetic material between the stator and the rotor of the motor, the seal at the rotating part is unnecessary. However, since this method requires a large gap between the stator and the rotor, the loss in transmitting the magnetic flux generated on the stator side to the rotor side increases, and the overall efficiency of the motor and pump There is a problem of causing a decrease in

  On the other hand, in motors and generators used in these systems, a soft magnetic material is used for the iron core part, and reducing the loss of the iron core part is a means for realizing higher efficiency of these products. It has become. Another measure to improve efficiency is to use a permanent magnet with a high magnetic force to increase the magnet torque per predetermined current so that the required torque can be obtained at a low current. There is a means for reducing (copper loss). However, in recent years, there has been a background that it has become difficult to use magnets with high magnetic force due to soaring rare earths. Therefore, there is a need for a method for increasing the efficiency even when a magnet having a weak magnetic force is used. Patent Document 3 is cited as a method for improving the efficiency of a permanent magnet motor. In Patent Document 3, an axial gap type motor is used in order to use a low-loss amorphous material for a soft magnetic material used in a permanent magnet motor, and the volume of the permanent magnet is increased in order to reduce copper loss. A motor having a configuration in which the two surfaces are rotors has been proposed.

  When this axial gap type motor is applied to a system having an impeller such as a pump to achieve high efficiency and downsizing, the structure in which the impeller is directly arranged on the output shaft has a large diameter in the liquid. Rotating the disc increases the disc friction loss, leading to a reduction in efficiency. Further, if the structure is such that the output shaft is extended from the disc, there remains a problem that the shaft is long in the axial direction as in the normal pump described above and the shaft between the pump portion must be sealed.

JP 2009-077531 A Japanese Patent No. 4828751 JP 2010-115069 A

  In the pump system having the structure disclosed in Patent Documents 1 and 2, since the gap between the stator and the rotor is widened, the magnetic resistance, which is the ease of flow of magnetic flux between the stator and the rotor, is increased. There is a problem of increasing the motor efficiency and causing a decrease in motor efficiency. In addition, in application to an axial gap structure pump system or the like that increases the motor efficiency disclosed in Patent Document 3, because the diameter of the disk is large, there is a concern that the disk friction loss increases and the pump efficiency decreases. Has a problem.

  The object of the present invention is to realize the isolation of the motor from the impeller chamber filled with liquid without increasing the gap and keep the motor highly efficient, and to improve the efficiency of the motor itself by applying the axial gap structure. An object of the present invention is to provide a system having an axial gap type impeller having high reliability and system efficiency without increasing the diameter of an impeller such as a pump.

  In order to solve the above-described problems, the present invention provides an axial gap type rotating electric machine having at least two rotors as a motor unit, and the gap between the stator and the rotor is appropriately dimensioned to obtain the maximum efficiency. A configuration is proposed in which the rotor is partitioned from one side of the rotor to the impeller by a partition wall of a non-magnetic member, and torque is transmitted in a non-contact manner.

  As a specific structure, in order to increase the volume of the magnet, in an axial gap rotating electrical machine having a rotor on both axial sides of an axial gap type rotating electrical machine configured to have a large diameter, either one of the rotor shafts Place magnets with multiple poles in the circumferential direction on the side opposite to the direction of the stator, and arrange the same number of magnets on the side of the axial motor on the impeller side that transmits torque so that the magnets face each other A structure in which torque is transmitted in a non-contact manner by repulsive attraction of a magnet is used as a structure in which the rotors separated are separated by a non-magnetic member and a non-conductive partition.

  With the above structure, the rotating electrical machine can be configured as an axial gap type that can improve efficiency. Since the impeller side and the rotating electrical machine side are partitioned by a partition wall, only the impeller side is conveyed by the impeller. Therefore, it is possible to realize a structure that does not increase the rotor disk friction loss on the axial gap type rotating electrical machine side. In addition, since the rotating electrical machine portion is configured independently, the gap between the stator and the rotor as a motor is appropriately maintained, so that a structure that does not reduce the efficiency of the motor can be realized. .

  According to the present invention, a system having an impeller such as a pump that is high in efficiency and thin in the axial direction because the gap of the rotating electrical machine is not enlarged to reduce the efficiency of the motor and the disk friction loss is not increased. Can be configured. In addition, since an axial gap motor with a large rotor diameter can be configured, an impeller drive system having a rotating electrical machine having high efficiency with an inexpensive magnet with low magnetic force can be configured without using a strong magnet having a rare earth. Can do.

It is a cross-sectional view explaining the impeller drive system of this invention. It is the perspective view which showed the structure of the axial gap type rotary electric machine part which has a magnet rotor on both axial direction surfaces of this invention. It is a figure which shows the iron core structure of the axial gap type rotary electric machine part which has a magnet rotor on both axial direction surfaces of this invention. It is a figure which shows the torque transmission side rotor structure of the axial gap type rotary electric machine part which has a magnet rotor on both axial direction surfaces of this invention. It is a perspective view which shows the structure of the impeller side rotor of the impeller drive system of this invention. It is a perspective view which shows the housing structure which has the impeller side rotor and partition wall of the impeller drive system of this invention. It is a figure which shows 2nd Embodiment of the torque transmission side rotor structure of the axial gap type rotary electric machine part which has a magnet rotor on both axial surfaces of this invention. In the impeller drive system of this invention, it is a cross-sectional view explaining the various patterns as a rotor structure which transmits torque without contact.

  Embodiments of the present invention will be described below with reference to the drawings.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a cross-sectional view of an impeller drive system configured by integrating an axial gap type motor and an impeller according to the present invention. FIG. 2 is a perspective view showing the structure of the axial gap motor portion of the impeller drive system.

  The axial gap type motor has a plurality of iron cores 1 in the circumferential direction, and a stator 100 is constituted by a coil 2 in which a conductor is wound around the iron core 1. The stator is arranged at the center in the axial direction, and has a structure having two rotors on both sides in the axial direction. The non-output-side rotor has a structure in which the non-output-side rotor magnet 12 is held by the non-output-side rotor 10 via the anti-output-side rotor yoke 11. In this embodiment, the magnet is divided and arranged in the circumferential direction, and the inter-magnet positioning member 13 is arranged between the magnets. A hole into which the rotating electrical machine shaft 5 is inserted and fixed is provided at the center of the counter-output-side rotor 10 and is fixedly coupled to the rotating electrical machinery shaft 5. The rotating electrical machine part shaft 5 is held in a rotatable state by a bearing 6 disposed rotatably in a bearing holding part 4 provided inside the stator 100 and is coupled to an output-side rotor 20. The output-side rotor 20 has the same configuration as that of the counter-output-side rotor 10 and includes an output-side rotor yoke 21, an output-side rotor magnet 22, and an inter-magnet positioning member 23, and the output-side rotor. The magnet 22 is arranged on the surface on the stator side so as to face the stator 100, so that an axial gap type motor capable of rotating the rotors 10 and 20 is configured.

  Further, the output-side rotor 20 has a surface that does not face the stator 100, that is, a surface on which the impeller 16 is disposed, and an output-side rotor torque transmission-side magnet that is magnetized in a plurality of poles in the circumferential direction. 24 is arranged. Between the output side rotor torque transmission side magnet 24 and the impeller 16, it is configured integrally with a casing 7 that holds the outer peripheral portion (stator holding portion 3) of the stator 100 of the axial type motor. The casing partition wall 7a is disposed, and the axial motor section and the impeller 16 section are configured to partition the space. The housing partition 7a is a non-conductor and is preferably made of a non-magnetic material. However, if the casing partition wall 7a is made thin, a resin material such as plastic cannot secure the strength, and may be made of a nonmagnetic metal such as stainless steel. The casing partition wall 7a is provided with an impeller shaft 9 at the center, and is rotatably supported by an impeller bearing 8 provided on the inner peripheral portion of the impeller 16 with respect to the shaft. The thrust direction of the impeller 16 has a structure in which a screw portion provided at the tip of the impeller portion shaft 9 is fixed by an impeller fastening portion washer 18 and an impeller fastening nut 15. Further, the motor side of the impeller 16, that is, the surface of the impeller side rotor 30 on the housing partition wall 7a side, has the same number of poles as the output side rotor torque transmission side magnet 24 provided in the motor unit. The impeller side rotor magnet 32 is disposed and integrated with the impeller 16. Thus, torque is transmitted in a non-contact manner by the attractive force of the output side rotor torque transmission side magnet 24 and the impeller side rotor magnet 32. The torque that can be transmitted by this magnetic coupling can be increased because the permanent magnet and the permanent magnet face each other and the gap magnetic flux can be increased. For this reason, even with a structure having a large gap through the housing partition wall 7a, it is possible to transmit the torque generated in the motor unit over the entire surface. For the above reason, the area of the non-contact torque transmission surface can be reduced as necessary.

  In the embodiment shown in FIG. 1, the impeller side rotor magnet 32 on the impeller 16 side is an example having a smaller diameter than the output side rotor torque transmission side magnet 24. With the configuration as described above, the impeller 16 can partition the room where the impeller 16 performs work by stirring fluids such as water, oil, and air and the motor unit by the housing partition wall 7a. The disk friction loss generated by the two rotor disks can be reduced.

  In FIG. 3, it shows about the Example from which the structure of the iron core of a motor part differs. FIG. 4A shows an iron core having a structure in which foil strips such as electromagnetic steel plates or iron-based amorphous, fine met, and nanocrystal materials are laminated in the circumferential direction. Moreover, (b) is an example using the iron core which compression-molded powder, such as a dust core and a ferrite. (C) has shown the example which comprises such an iron core which shows the iron core of the structure which laminated | stacked foil strips, such as an electromagnetic steel plate or iron-based amorphous | non-crystalline amorphous, a fine met, and a nanocrystal material, in the circumferential direction as a rectangular cross section. (D) shows the iron core which gave directionality to the iron core of the soft-magnetic material shown to (a) to (c). In the axial gap motor of the present invention, since the magnetic flux flows only in the axial direction, an anisotropy is provided in this direction. Thus, in the axial gap motor of the present invention, a special magnetic material can be used, so that the motor efficiency can be designed extremely high.

  FIG. 4 is a perspective view showing the detailed structure of the output side rotor. (A) The figure shows the perspective view which looked at the output side rotor from the surface of the output side rotor torque transmission side magnet 24. The output-side rotor has a structure in which a structural member 20a such as iron, aluminum, or stainless steel is sandwiched between the output-side rotor torque transmission side magnet 24 and the output-side rotor magnet 22. (B) The figure shows the perspective view at the time of seeing what was shown in (a) figure from the opposite side. On the surface facing the motor side, a plurality of output-side rotor magnets 22 are arranged in the circumferential direction, and a positioning member 23 is arranged therebetween. The reason for this structure is that the motor unit needs to be configured to reduce cogging torque and torque pulsation generated between the iron core 1 and the magnet. The magnet shape of a present Example is comprised as a substantially sector shape in the circumferential direction, and is made into the shape from which the opening angle of the both sides differs. By adopting such a shape, torque pulsation can be reduced. In this embodiment, the shape of the magnet is such a shape, but a donut-shaped magnet may be configured by magnetization so as to have such a shape. FIG. 4C shows a cross-sectional view. It can be seen from the cross-sectional view that a donut-shaped yoke 21 is sandwiched between the magnet 22 and the structural member 20a. Since this yoke needs to be composed of a soft magnetic material, it is constructed by winding an amorphous foil strip or an electromagnetic steel plate, or a powder magnetic core obtained by compression molding a powdered soft magnetic material. FIG. 4D shows an example in which the output side rotor torque transmission side magnet 24 is configured as a rotor magnet 24 having a smaller diameter than the rotor of the axial gap motor. As described above, the magnet on the side that transmits torque in a non-contact manner has a structure in which the magnet and the magnet face each other and rotate synchronously, and therefore can transmit a large torque in a smaller area than the motor unit.

  FIG. 5 shows the structure of the impeller portion. (A) The figure is the perspective view seen from the impeller side. The impeller 16 has a structure having a plurality of blades in the circumferential direction, and has a function of creating a flow by stirring a medium such as water, air, or oil. It is set as the structure which has arrange | positioned the impeller side rotor magnet 32 in the surface facing the motor side of this impeller. A perspective view seen from the magnet side surface is shown in FIG. The impeller side magnet 32 disposed on the surface of the impeller side rotor 30 has a donut shape, and has a structure in which a slide bearing is disposed on the inner side.

  FIG. 6 is a perspective view showing the relationship between the housing 7 having the housing partition wall 7 a and the impeller 16. At the center of the partition wall, an impeller side shaft 9 made of metal or resin is formed integrally with the housing. This shaft has a structure in which it is integrally formed by insert molding when molding a shaft 7 made of resin as shown in FIG. And The casing partition wall 7a is configured such that the portion facing the magnet is as thin as possible, the shaft fixing portion is thick, and only the magnet facing surface is thinned. As shown in FIG. 5A, the impeller 16 is rotatably held on the shaft 9 via the slide bearing 8 and is fixed in the thrust direction by the washer 18 and the nut 15. It is structured to do.

Subsequently, a second embodiment of the present invention will be described with reference to FIG.
In the first embodiment, an example in which the output-side rotor is constituted by two types of magnets is shown. FIG. 7 shows an example in which these two magnets are shared. FIG. 7A is a perspective view showing the structure of the output side rotor. A hole for holding the magnet is provided in the structural member 20a of the rotor, and a magnet 22 having the same shape as the hole is inserted and fixed to form a rotor. The appearance of the rotor has a structure as shown in FIG. FIG. 7C shows a cross-sectional view of the entire system using this rotor. The only difference from FIG. 1 is the output side rotor. Compared with the first embodiment shown in FIG. 1, the cost can be reduced and the thickness can be reduced by the absence of the yoke 22 and the magnet positioning member 23 in the output-side rotor 20. However, in this case, the impeller side rotor needs to be the same as the number of poles of the motor magnet.

Next, a third embodiment of the present invention will be described with reference to FIG.
FIG. 8 shows a combination pattern of the structures of the output side rotor and the impeller side rotor. FIG. 8A shows the structure of the embodiment shown in FIG. The output-side rotor 20 has a donut-shaped yoke portion 21, an output-side magnet 22 is disposed on the motor-side surface, and a donut-shaped output-side rotor torque transmission-side magnet on the opposite surface. 24 is arranged. It faces the impeller side rotor 30 with a partition wall (not shown) interposed therebetween, and a donut shaped impeller side magnet 32 is arranged on the facing surface. This impeller side rotor 32 is smaller than the output side magnet 22. FIG. 8B shows a similar configuration. The output side magnet 22 and the impeller side rotor 32 have the same shape. With this shape, an increase in transmission torque can be expected due to an increase in magnetic force, so that the gap between the partition walls can be increased. FIG. 8C shows an example in which a soft magnetic material yoke 31 is also provided on the impeller side rotor side. Since the rotor on the impeller side is disposed in a coolant such as water or oil, it is desirable to use a rust preventive material such as aluminum or stainless steel rather than using a member that easily rusts such as iron. For this reason, when it becomes a nonmagnetic material, it is necessary to provide a yoke separately. The yoke is made of a material as described above and arranged on the back side of the magnet to prevent rust. FIG. 8D shows an example in which the output-side rotor torque transmission-side magnet 24 is made smaller than the motor part (rotor) diameter, and the impeller-side magnet 32 is similarly made smaller. Such a configuration is possible depending on the required torque. FIG. 8E shows only the impeller side rotor. As described above, since rust prevention is required, the structure in which the entire rotor portion is coated with a material capable of rust prevention is shown. FIG. 8F shows an example in which the impeller, the magnet 32, the yoke 31, and the plain bearing 8 are integrated with resin. The impeller itself is made of resin, and when the shape is molded with a mold, it is characterized in that it can be integrated with insert molding of other members such as magnets to prevent rust.

  The impeller drive system integrated with the motor of the axial type structure of the present invention can be applied to a wide range of applications aiming at small size and high efficiency. Specifically, a system using an impeller integrated with an axial gap motor according to the present invention includes an industrial pump, a compressor, an industrial fan, a small hydropower turbine power generation system, an in-vehicle electric water pump, and an in-vehicle electric oil pump. It can be widely applied to general rotating machine systems such as home appliance pumps and home appliance blowers, and drive and power generation systems using impellers.

DESCRIPTION OF SYMBOLS 1 Stator iron core 2 Stator coil 3 Stator holding | maintenance part 4 Bearing holding | maintenance part 5 Rotating electrical machinery part axis | shaft 6 Bearing 7 Housing 7a Housing partition 8 Impeller part bearing 9 Impeller part axis | shaft 10 Counter output side rotor 11 Counter output side rotation Secondary yoke 12 Non-output side rotor magnet 15 Impeller fastening nut 16 Impeller 18 Impeller fastening portion washer 20 Output rotor 21 Output rotor rotor 22 Output rotor magnet 23 Magnet positioning member 24 Output Side rotor torque transmission side magnet 30 Impeller side rotor 32 Impeller side rotor magnet

Claims (6)

In a motor-integrated impeller system configured by integrating an axial gap motor and an impeller,
A stator,
A shaft passing through the stator;
A first rotor and a second rotor disposed in the axial direction with the stator interposed therebetween;
An impeller part having an impeller disposed in an axial direction opposite to the stator with respect to the first rotor;
A non-magnetic partition wall disposed between the first rotor and the impeller and partitioning the space in a direction perpendicular to the axis;
A torque transmission side magnet disposed between the first rotor and the partition;
An impeller-side rotor magnet disposed between the partition wall and the impeller unit, and disposed on an impeller shaft and a dynamic shaft of the impeller;
A motor-integrated impeller system that performs torque transmission to the impeller in a non-contact manner by the attractive force of the torque transmission side magnet and the impeller side rotor magnet. The motor-integrated impeller system according to claim 1,
The motor-integrated impeller system, wherein the torque transmission side magnet and the impeller side rotor magnet have the same number of poles. The motor-integrated impeller system according to claim 2,
A housing for holding the outer periphery of the stator;
The motor-integrated impeller system, wherein the casing and the partition wall are integrally formed. The motor-integrated impeller system according to claim 2,
A motor-integrated impeller system, wherein the inner and outer diameters of the magnets constituting the axial gap motor and the magnets arranged in the impeller are different. The motor-integrated impeller system according to claim 2,
A non-magnetic, non-conductive (resin) partition and a fixed shaft for impeller rotation holding provided on the partition are configured, and can be rotated in the rotational direction and thrust direction by a slide bearing provided on the inner periphery of the impeller. A motor-integrated impeller system characterized by having a structure that realizes holding. The motor-integrated impeller system according to claim 2,
A motor-integrated impeller system characterized in that the impeller part is coated for rust prevention.