JP2013255327A - Magnet motor and pump device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnet motor that can secure necessary torque characteristics even when using a ferrite magnet having weak coercive force and magnetize the ferrite magnet externally.SOLUTION: A magnet motor includes a rotor which has a plurality of permanent magnets radially arranged and also has a magnetic pole core arranged with the permanent magnets interposed, and a stator which has armature windings of three phases wound in slots provided in a stator core. The rotor includes a shaft and a rotor core, and is formed by molding a rotor assembly having the shaft and the rotor core pressed in or shrinkage-fitted and a magnetic pole assembly of the magnetic pole core and the permanent magnets out of resin, peripheral surfaces of the permanent magnets being in a mutually projection shape.

Description

  The present invention relates to a magnet motor and a pump device using the same.

  A magnet motor is adopted as a drive source of the current pump device, a ferrite magnet is adopted as a low output magnet motor, and a neodymium magnet is adopted as a high output magnet motor. Since neodymium, which is the main raw material for this neodymium magnet, is a rare metal and may be difficult to obtain, it is required to use a ferrite magnet even in a high-power magnet motor.

  However, since the residual magnetic flux density of the neodymium magnet is 1.3 T, the residual magnetic flux density of the ferrite magnet is as small as 0.45 T (about 1/3), and there is a problem that the size of the ferrite magnet motor becomes large. In order to use this for the pump device, it was necessary to increase the size of the pump device.

  Since the amount of magnetic flux from the magnet depends on the circumference of the ferromagnetic surface of the magnet, as a technique for avoiding the above problem, a configuration in which flat ferrite magnets are arranged radially has been proposed (Patent Document 1,). Non-patent document 1).

JP 2006-20425 A

T.A. A. LIPO, "Alternator Design", Denki Shoin, May 2007, P559-564

  In the case of Patent Document 1 and Non-Patent Document 1, since the ferrite magnet extending radially with respect to the outer diameter of the rotor is long, a high output torque can be obtained even if the ferrite magnet is used.

  On the other hand, since the magnet motor of the pump device is small, the radial distance from the outer periphery of the rotor to the shaft is short, and when the magnet approaches the shaft, the magnet cannot be externally magnetized. There is a problem that it is impossible to obtain a high output torque by applying the configuration of Document 1.

  The present invention is a small magnet motor capable of obtaining a high torque output as well as using a neodymium magnet even when a ferrite magnet having a weak coercive force is used, and capable of magnetizing a ferrite magnet. The purpose is to provide.

  In order to achieve the above object, the magnet motor according to claim 1 has a plurality of permanent magnets arranged radially and a plurality of magnetic cores arranged radially so as to sandwich each of the plurality of permanent magnets. A magnet motor comprising a rotor and a stator in which a three-phase armature winding is wound in a slot provided in a stator core, wherein circumferential surfaces of the permanent magnets are convex with respect to each other It was.

  According to the above configuration, even if a ferrite magnet having a weak coercive force is used, the required torque characteristics can be secured and the ferrite magnet can be externally magnetized.

The longitudinal cross-sectional view of the pump apparatus of one Example. The right view of FIG. The top view of the state which removed the pump cover of FIG. The longitudinal cross-sectional view of the magnet motor of one Example. The radial direction sectional view of the magnet motor of one example. The radial direction sectional view of the primary fabrication object of one example. The schematic diagram which showed the mode at the time of magnetizing. The structural diagram of the rotor of the magnet motor of one Example.

  Hereinafter, the pump apparatus 100 of one Example of this invention and the magnet motor 3 used for it are demonstrated with reference to FIGS.

  First, the pump apparatus 100 of a present Example is demonstrated using FIGS. 1-3. 1 is a longitudinal sectional view of the pump device 100, FIG. 2 is a right side view of FIG. 1, and FIG. 3 is a plan view of the pump device 10 with the pump cover 10 removed.

  As shown in FIG. 1, the pump device 100 includes a base 1 in which a water passage is formed, and a suction-side water passage 1 a and a discharge-side water passage 1 b provided in the base 1. As shown in FIGS. 2 and 3, the pump device 100 controls the pressure tank 2 placed on the top of the base 1, the pump driving magnet motor 3 placed on the base 1, and this. A control device 4, a display substrate 5 of the control device 4, a harmonic suppression coil 6 that suppresses noise from the control device 4, and a pressure sensor 7 provided in the discharge-side water passage 1b. 10 is a covered structure.

  As shown in FIG. 1, the pump unit 15 includes an impeller 16, a casing 17 in which the impeller 16 is placed, and a casing cover 18 that closes the front surface of the casing 17. The pump unit 15 is called a Wesco pump, and has a suction port 17 a and a discharge port 17 b in the casing 17. An air-water separation chamber 19 is provided at the top of the pump unit 15. The steam-water separation chamber 19 is connected by a suction pipe 20 so as to communicate with the suction-side water passage 1 a of the base 1.

  A suction flange 21 for pipe connection is attached to the end surface on the base 1 side of the suction side water passage 1a. Further, a check valve 22 is provided in the air / water separation chamber 19 above the suction pipe 20. The check valve 22 allows water to flow from the suction port side to the casing 17 side, but operates to prevent reverse flow.

  The steam / water separation chamber 19 is connected by a discharge pipe 23 so as to communicate with the discharge-side water passage 1 b of the base 1. A discharge flange 24 for pipe connection is attached to the end surface on the base 1 side of the discharge side water passage 1b.

  Further, a screw-in type priming water supply plug 25 is provided in the upper part of the air / water separation chamber 19, and the priming water is supplied by removing the priming water supply plug 25.

  The operation of the pump device 100 is performed by supplying a current from the control device 4 to the magnet motor 3 for driving the pump. First, the self-priming operation is performed, and after the self-priming operation is finished, the pumping operation is started.

  In the self-priming operation, the priming water in the steam / water separation chamber 19 is recirculated from the casing discharge port 17b and the air is discharged, and the upstream air gradually escapes from the casing suction port 17a of the pump unit 15 to fill the water. . Then, when the water is completely filled, the self-priming operation is completed and the pumping operation is started.

  In the pumping operation, the sucked-up water is sent out from the discharge pipe via the discharge flange 24. In such a pumping operation, when the flow path connected to the discharge pipe is closed, the pressure on the downstream side from the discharge pipe rises. Normally, the pressure sensor 7 detects this pressure and stops the operation of the magnet motor 3 for driving the pump. The pump apparatus 100 operates by such an operation.

  Next, the structure of the magnet motor 3 will be described in detail with reference to FIGS. 4 is a longitudinal cross-sectional view of the magnet motor 3, FIG. 5 is a radial cross-sectional view of the magnet motor 3, FIG. 6 is a radial cross-sectional view of the primary molded body, and FIG. 8 is a structural diagram of the rotor of the magnet motor 3.

  First, the outline of the magnet motor 3 used in the pump device 100 will be described with reference to the cross-sectional view of FIG. As shown here, the magnet motor 3 is covered with housings 30a and 30b, and both ends of the shaft 36 of the magnet motor 3 are rotatably supported by bearings 51a and 51b. A stator 35 is press-fitted in the housing 30a, and a rotor 50 fitted to the shaft 36 is provided on the inner peripheral side. A cooling fan 52 for generating cooling air is attached to one end of the shaft 36, and a part of the cooling air generated here cools the magnet motor 3 for driving the pump via the housing 30a, Some cool the control device 4 through the motor cover 53 and the ventilation duct 54.

  Next, the configuration of the stator 35 of the magnet motor 3 will be described with reference to FIG. As shown in this radial cross-sectional view, the stator 35 has a three-phase concentrated armature composed of a U phase, a V phase, and a W phase through an insulator 33 in a slot 32 formed in the stator core 31. The winding 34 is wound.

  Next, the configuration of the rotor 50 of the magnet motor 3 will be described in detail with reference to FIG. As shown in this radial cross-sectional view, a rotor core 37 is fitted to the shaft 36, and this is hereinafter referred to as a rotor assembly. In addition, the fitting method of both may be press-fitting or shrink fitting. On the outer periphery of the rotor assembly, an annular shape in which ferrite magnets 38 (permanent magnets) whose circumferential surfaces are mutually convex and magnetic cores 39 whose circumferential surfaces are mutually concave are alternately arranged radially. A structure is configured, which is hereinafter referred to as a magnetic pole assembly.

  A method of forming the magnetic pole assembly will be described with reference to FIG. First, as shown in FIG. 6A, the ferrite magnets 38 and the magnetic pole cores 39 before magnetization are alternately arranged radially. As a result, the ferrite magnet 38 before magnetization can be sandwiched between the magnetic pole cores 39. Then, as shown in FIG. 6B, the primary molded body 43 is molded by filling a primary molding resin 41 between the ferrite magnet 38 and the magnetic pole core 39. The slit hole 40 of the magnetic pole core 39 and the inner and outer peripheral surfaces of the magnetic pole core 39 are not filled with the primary molding resin 41. Therefore, in the primary molded body 43, the inner and outer peripheral surfaces of the slit hole 40 and the magnetic pole core 39 are exposed. To do.

  Next, a method of magnetizing the ferrite magnet 38 of the primary compact 43 will be described with reference to FIG. In FIG. 7, the outer peripheral magnetized yoke 46 is obtained by winding an outer peripheral magnetized coil 45 around a slot 44, and the inner peripheral magnetized yoke 49 is obtained by winding an inner peripheral magnetized coil 48 around a slot 47. Then, after the primary molded body 43 is installed so that the ferrite magnet 38 is positioned between the outer peripheral magnetized coil 45 and the inner peripheral magnetized coil 48, a predetermined current is supplied to both the magnetized coils, thereby performing the primary molding. The ferrite magnet 38 constituting the body 43 can be magnetized.

  Thereafter, the primary molded body 43 and the rotor assembly are arranged as shown in FIG. 8 and the secondary molded resin 42 is filled between them, so that the rotor 50 is a secondary molded body in which both are integrated. Can be obtained. Thus, since the shaft 36 and the ferrite magnet 38 are integrally molded, torque acting on the ferrite magnet 38 is transmitted to the shaft 36 via the secondary molding resin 42 and the rotor core 37. In addition, since the secondary molding resin 42 is filled in the plurality of grooves 37a provided in the rotor core 37 and the slit holes 40 that are not filled with the resin during the primary molding, the rotor 50 is firmly integrated. It becomes.

  The configuration and the manufacturing method of the magnet motor 3 for driving the pump according to the present embodiment have been described above. The characteristics will be described.

  Patent Document 1 and Non-Patent Document 1 describe a configuration in which flat magnets are arranged radially and extend to the vicinity of the shaft. In this configuration, if the lower limit width of the magnetic core is narrow, an inner peripheral magnetized yoke is used. A ferrite magnet cannot be fully magnetized, and it is necessary to assemble a magnetized ferrite magnet. When a magnetized ferrite magnet is assembled, the ferrite magnet will stick to either the left or right magnetic core even if the position of the magnetic core is accurately defined, so the amount of magnetic flux flowing from the top of the magnetic core to the stator side The motor characteristics cannot be kept uniform. Further, if the lower limit width of the magnetic pole core is widened and the ferrite magnet is extended to the shaft, the magnetic flux leaks to the shaft, and the necessary characteristics cannot be obtained.

  On the other hand, in the magnet motor 3 of the present embodiment, the circumferential surfaces of the ferrite magnets 38 (permanent magnets) have a convex shape, and the magnetic pole core 39 and the magnetic pole assembly of the ferrite magnets 38 are primarily molded with the primary molding resin 41. Thus, the primary molded body 43, the ferrite magnet 38 of the primary molded body 43 is magnetized from the inner and outer circumferences, and the rotor assembly and the primary molded body 43 in which the shaft 36 and the rotor core 37 are fitted are formed into the secondary molded resin 42. The rotor 50 is obtained by secondary molding. That is, the ferrite magnets 38 are externally attached by increasing the amount of magnetic flux by making the circumferential surfaces of the ferrite magnets 38 convex to each other, shortening the length of the ferrite magnets 38 and increasing the lower limit width of the magnetic pole core 39. Magnetization is possible, and the mass productivity of the rotor 50 can be increased.

3 Magnet motors 30a, 30b Housing 31 Stator cores 32, 44, 47 Slot 33 Insulator 34 Armature winding 35 Stator 36 Shaft 37 Rotor core 38 Ferrite magnet 39 Magnetic pole core 40 Slit hole 41 Primary molding resin 42 Secondary Molded resin 43 Primary molded body 45 Outer peripheral magnetized coil 46 Outer peripheral magnetized yoke 48 Inner peripheral magnetized coil 49 Inner peripheral magnetized yoke 50 Rotors 51a, 51b Bearing 52 Cooling fan 53 Motor cover 54 Ventilation duct 100 Pump device

Claims (5)

A rotor having a plurality of permanent magnets arranged radially, and a plurality of magnetic pole cores arranged radially so as to sandwich each of the plurality of permanent magnets;
A stator in which a three-phase armature winding is wound in a slot provided in the stator core;
A magnet motor comprising:
2. A magnet motor according to claim 1, wherein circumferential surfaces of the permanent magnets are convex. The magnet motor according to claim 1,
The rotor further includes a shaft and a rotor core,
The rotor is formed by molding a rotor assembly in which the shaft and the rotor core are press-fitted or shrink-fitted and a magnetic pole assembly in which the permanent magnet and the magnetic core are combined. Magnet motor characterized by The magnet motor according to claim 2,
After magnetizing a permanent magnet of a primary molded body obtained by primary molding of the magnetic pole assembly with a primary molding resin from the inner and outer circumferences using a magnetized yoke,
A magnet motor, wherein the rotor is formed by secondary molding of the rotor assembly and the magnetic pole assembly. The magnet motor according to claim 3, wherein
During the primary molding, the resin is not filled in the slit hole of the magnetic core,
In the secondary molding, the slit motor is filled with a resin in a slit hole of the magnetic pole iron core.   The pump apparatus which used the magnet motor as described in any one of Claims 1-4 as a drive source.