JP2008223666A - Fan motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems that it is difficult to enhance durability when incorporating bearing parts that are subjected to secular deterioration, such as a roller bearing or a sliding bearing, to a fan motor, and it becomes bigger in size, and it has also disadvantage in terms of manufacturing cost. <P>SOLUTION: An outer rotor type motor of a fan motor has an outer rotor cup integrally fixed to an impeller, a rotating shaft fixed to the axis part of the outer rotor cup, an annularly circular rotor magnet fixed on the inner surface of circumferential wall of the outer rotor cup, and a stator having a plurality of sets of coils. At least an outer surface of the circumferential wall of the outer rotor cup is formed into a partial spherical surface having its center at a point on the axis of the impeller and with decreasing radius as it moves toward the intake side of casing, a supporting shaft for supporting the end of the rotating shaft with a point contact at the center of the partial spherical surface is provided concentrically to the rotating shaft, and a base plate to which the supporting shaft is fixed and which supports the stator is fixedly provided in the casing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fan motor having a casing, an impeller housed in the casing, and an outer rotor type motor that is mostly disposed inside the impeller.

  Conventionally, in an outer rotor type fan motor, an impeller and an outer rotor cup are connected via a rotating shaft, the rotating shaft is supported by a roller bearing or a sliding bearing, a rotor magnet is fixed to the inner periphery of the outer rotor cup, and is wound around a stator. A rotating magnetic field is generated by switching energization to the plurality of rotated coils, and the rotor magnet, the outer rotor cup, and the impeller are rotationally driven integrally with the rotating shaft.

  In general, the outer rotor cup is configured in a cup shape having a cylindrical portion, and is arranged outside the impeller. In this case, since the motor protrudes to the outside, the fan motor becomes large. Therefore, recently, in order to reduce the size of the fan motor, a technique for incorporating the motor into the inner space of the impeller has been proposed.

  For example, in Patent Document 1, an outer rotor cup, a rotor magnet mounted on the inner surface of the outer rotor cup, and a stator having a plurality of coils are formed in a truncated cone shape so as to be reduced in diameter toward the suction port of the casing. An outer rotor type fan motor is disclosed in which the motor is accommodated in the inner space of the impeller. In order to support the rotating shaft provided in the axial center part of the outer rotor cup, a cylindrical member fixed to the casing is provided inside the stator, and the rotating shaft is supported by the cylindrical member by a pair of sliding bearings.

Patent Document 2 discloses an outer rotor type fan motor in which a rotor and a stator are formed in a truncated cone shape and accommodated in an inner space of an impeller, like the outer rotor type fan motor of Patent Document 1. The rotor has a return path forming ring and a rotor magnet.
The stator has a pair of claw-shaped magnetic poles and an annular coil wound around a coil frame housed therebetween. A rotating shaft or a rotating sleeve fixed to the rotor is rotatably supported by a stationary member on the casing side via a bearing.

JP 2005-160264 A JP-T 2006-512038

At present, in a heat source device such as a water heater, air of a blowing amount adapted to a gas supply amount of fuel gas supplied to a burner is supplied from a fan motor, and the blowing amount is a table preset in a control device. It is set by controlling the fan motor speed based on the above.
Here, by monitoring the driving state such as the current value and voltage value of the fan motor and the feedback amount of the rotational speed control, it is possible to detect a decrease in the performance of the fan motor due to dust attached to the impeller and bearing wear due to secular change. And the technique of ensuring the stable ventilation volume is taken by taking the countermeasures against them.

  However, a pair of ball bearings and sliding bearings are generally used for the bearings that support the rotation shaft of the fan motor. However, when such bearing parts are used, the effect of changes in sliding resistance due to aging changes. Therefore, it is difficult to secure a stable air flow rate. Moreover, since ball bearings and sliding bearings are incorporated, there is a problem that not only the manufacturing cost of the fan motor is high, but also the durability is poor.

On the other hand, in order to increase the durability of the motor, it is not impossible to use air bearings or magnetically levitated bearings. However, when these bearings are used, the structure is complicated because many parts with high accuracy are used. There is a problem that the size and size are increased, and the production cost is also increased.
An object of the present invention is to provide a fan motor which is not affected by changes in sliding resistance of a bearing due to secular change, has excellent durability, has a simple structure, and is advantageous in manufacturing cost.

  According to another aspect of the present invention, a fan motor includes a casing having a suction port and a discharge port, an impeller housed in the casing and having a plurality of blades, and an outer rotor type motor, most of which is disposed inside the impeller. The outer rotor type motor includes an outer rotor cup that is integrally fixed to an impeller, a rotary shaft that is fixed to an axial center portion of the outer rotor cup, and a circle that is fixed to an inner surface of a peripheral wall portion of the outer rotor cup. The outer rotor cup has an annular rotor magnet and a stator having a plurality of sets of coils, and the outer surface of at least the peripheral wall portion of the outer rotor cup is centered on a point on the axis of the impeller and moves toward the suction port side of the casing. A support shaft formed concentrically with the rotary shaft is formed on the partial spherical surface to be reduced in diameter, and supports the tip of the rotary shaft by point contact at the center of the partial spherical surface. It is, is characterized in that the base plate having a base end portion of the support shaft for supporting and the stator is fixed is fixedly provided in the casing.

  In this fan motor, the rotating shaft is fixed to the axial center portion of the outer rotor cup, and the tip portion of the rotating shaft is positioned at the center of the partial spherical surface forming the outer surface of the peripheral wall portion of the outer rotor cup. Since it is received and supported by point contact at the tip of the fixed support shaft, bearing components that change with time such as ball bearings and sliding bearings can be omitted, and the bearing structure can be simplified, downsized, and improved in durability.

  Since an annular rotor magnet is fixed to the inner surface of the outer peripheral wall portion of the outer rotor cup and a magnetic force acts between the rotor magnet and the annular magnetic body of the stator, the outer rotor cup, the rotor magnet, the rotating shaft, and the impeller Is always maintained in a neutral posture that coincides with the axis of the support shaft.

  As described above, when the tip of the rotating shaft is supported by the support shaft by point contact at the center of the sphere, the external force acting on the impeller in the direction perpendicular to the axial center is not uniform over the entire circumference. In some cases, the impeller, the outer rotor cup, the rotor magnet, and the rotating shaft may swing around the point contact portion as a swing center.

  However, since the outer surface of at least the peripheral wall portion of the outer rotor cup is formed in a partial spherical surface that is centered on a point on the impeller shaft center and decreases in diameter toward the suction port side of the casing, the impeller and the outer rotor cup Even if the rotor magnet or the like swings as described above, it can be configured such that they do not interfere with the stator.

The fan motor of claim 2 is characterized in that, in the invention of claim 1, the outer surface of the rotor magnet is formed into a partial spherical surface that is in close contact with the inner surface of the peripheral wall portion of the outer rotor cup.
A fan motor according to a third aspect is characterized in that, in the invention according to the first or second aspect, a front end portion of the outer rotor cup on the suction port side of the casing is formed on a flat wall.

The fan motor according to claim 4 is the invention according to claim 1 or 2, wherein the tip of the outer rotor cup on the suction port side of the casing is formed on a partial spherical wall continuously connected to the peripheral wall portion. It is a feature.
According to a fifth aspect of the present invention, a heat source apparatus includes the fan motor according to any one of the first to fourth aspects.

  According to the first aspect of the present invention, the rotation shaft fixed to the axial center portion of the outer rotor cup is supported by point contact at the center of the partial spherical surface forming at least the outer surface of the outer wall portion of the outer rotor cup. Since the base end of this support shaft is fixed to the base plate fixed to the casing, the bearing parts that change over time such as ball bearings and sliding bearings are omitted, and the bearing structure is simplified and miniaturized. Durability can be increased.

  Since the outer surface of at least the peripheral wall portion of the outer rotor cup is formed so as to be a partial spherical surface centering on a point on the impeller shaft center and becoming smaller in diameter toward the suction port side of the casing, one point contact support Even if the outer rotor cup, the rotor magnet, and the rotating shaft oscillate with the center of oscillation, the structure can be easily configured so that they do not interfere with the stator. In other words, by configuring at least the outer surface of the peripheral wall portion of the outer rotor cup as a partial spherical surface, it is possible to support the rotating shaft at one point by point contact with the supporting shaft.

  According to the invention of claim 2, since the outer surface of the rotor magnet is formed into a partial spherical surface that is in close contact with the inner surface of the outer wall of the outer rotor cup, the annular magnet is brought into close contact with the inner surface of the outer wall of the outer rotor cup and screwed. And can be fixed with an adhesive or the like.

According to the third aspect of the present invention, since the tip of the outer rotor cup on the suction port side of the casing is formed on the flat wall, the diameter of the outer rotor type motor is made larger than the axial length of the impeller. can do.
According to the fourth aspect of the present invention, the front end portion of the outer rotor cup on the suction port side of the casing is formed on the partial spherical wall continuously connected to the peripheral wall portion. Excellent guide for guiding.

  According to the invention of claim 5, in the heat source device provided with the fan motor, since the bearing component that increases the frictional resistance due to secular change is not adopted in the fan motor, it has excellent durability and combustion air. The air amount control for controlling the air amount is simplified.

  A fan motor according to the present invention includes a casing having a suction port and a discharge port, an impeller housed in the casing and having a plurality of blades, and an outer rotor type motor that is mostly disposed inside the impeller. The outer rotor type motor has an outer rotor cup, a rotor magnet, and a stator having a plurality of sets of coils, and supports the tip of the rotating shaft of the axial center portion of the outer rotor cup by a point contact with a support shaft. is there.

Embodiments of the present invention will be described below with reference to FIGS.
The present embodiment is an example in which the fan motor 10 of the present invention is applied to a hot water supply device (this corresponds to a heat source device).

  As shown in FIG. 1, a water heater 1 includes a water heater body 2, a gas supply pipe 40 that supplies fuel gas to the water heater body 2, a water supply pipe 41 that supplies water to the water heater body 2, A hot water discharge pipe 42 for discharging hot water from the main body 2, a drainage channel 43 for discharging drain generated in the auxiliary heat exchanger 7 during the recovery of latent heat, an operation panel 44 for operating the hot water supply device 1, and a hot water supply device 1 is provided with a control unit 45 (C / U) for controlling the entire system 1.

  The gas supply pipe 40 is connected to the gas supply port of the gas supply source and extends to the burner 5. One end of the water supply pipe 41 is connected to a water supply port connected to the water pipe, and the other end is connected to the auxiliary heat exchanger 7. One end of the tapping pipe 42 is connected to the main heat exchanger 6 and the other end is connected to a tapping port, and hot water is supplied from the tapping port to each facility such as a kitchen and a bath.

  The water heater main body 2 includes a main body case 3 and an exhaust cover (not shown). A combustion chamber 4 is formed in the main body case 3. The combustion chamber 4 includes a burner 5 for burning fuel gas, and a burner. A main heat exchanger 6 that recovers sensible heat from the combustion gas 5 is provided, and a sub heat exchanger 7 for recovering latent heat is provided above the main heat exchanger 6. A fan motor 10 that supplies combustion air to the burner 5 and a temperature sensor 9 that detects the ambient temperature are provided at the lower end of the main body case 3.

Next, the fan motor 10 will be described in detail.
FIG. 2 is a front view of the outer rotor type fan motor 10 of this embodiment, and FIG. 3 is a cross-sectional view taken along the line III-III of FIG. As shown in FIGS. 2 and 3, the fan motor 10 has a casing 11, a circular suction port 12 is formed on the front surface of the casing 11, and a rectangular discharge port 13 is formed on the upper end of the casing 11. .

  Inside the casing 11, an impeller 14 is disposed concentrically with the suction port 12 with its axis oriented horizontally. The impeller 14 is made of a synthetic resin having a plurality of blades 14a formed on the outer periphery. An outer rotor type motor 20 that rotationally drives the impeller 14 is provided in the casing 11, and most of the outer rotor type motor 20 is disposed inside the impeller 14, and the outer rotor type motor 20 is fixed to the casing 11. The base plate 21 is supported.

  As shown in FIG. 3, the outer rotor type motor 20 includes an outer rotor cup 30, a rotation shaft 32, a rotor magnet 33, a stator 23, a support shaft 26, and the like. In the following description, the left and right indicate the left and right in FIG. The outer rotor cup 30 is made of a synthetic resin material integrally with the impeller 14. The outer rotor cup 30 has a partially spherical peripheral wall 30a and a flat wall 30b that is connected to the right end (tip) of the outer rotor cup 30 and faces the suction port 12. The outer surface of the partially spherical peripheral wall 30a is the tip of the rotating shaft 32. Is formed as a partial spherical surface centered on a point where the support shaft 26 is supported by point contact, and the diameter of the partial spherical surface decreases as it moves toward the suction port 12 side.

  The left end portion of the outer rotor cup 30 is connected to the inner peripheral portion of the annular left end wall 14b of the impeller 14, and the surface of the outer rotor cup 30 that faces the base plate 21 is open. The flat wall 30b of the outer rotor cup 30 is formed in a circular shape smaller than the suction port 12, and a rotating shaft 32 is integrally formed at the center of the inner surface of the flat wall 30b, and the rotating shaft 32 is horizontal to the left with respect to the flat wall 30b. It extends to.

  As shown in FIGS. 3 and 4, the rotating shaft 32 is disposed concentrically with the impeller 14, and a metal support shaft 26 that supports the tip of the rotating shaft 32 by point contact is concentric with the rotating shaft 32. The left end of the support shaft 26 is fixed to the base plate 21. As shown in FIG. 4, a conical portion 26 a is formed at the tip of the support shaft 26, a concave portion 32 a is formed at the left end of the rotating shaft 32, and the tip of the conical portion 26 a of the supporting shaft 26 is a concave portion 32 a of the rotating shaft 32. The rotary shaft 32 is supported by the support shaft 26 so as to be rotatable and swingable. The tip of the conical portion 26 a of the support shaft 26 is the spherical center of the partial spherical surface of the outer surface of the peripheral wall portion 30 a of the outer rotor cup 30.

  The rotor magnet 33 is formed in an annular shape so as to cover substantially the entire inner surface of the peripheral wall portion 30a of the outer rotor cup 30, and the outer surface of the rotor magnet 33 is formed in a partial spherical surface that is in close contact with the inner surface of the peripheral wall portion 30a of the outer rotor cup 30. The rotor magnet 33 is fixed to the inner surface of the peripheral wall portion 30a of the outer rotor cup 30 by bonding or the like. The inner surface of the rotor magnet 33 is also formed in a partial spherical surface centered on the tip of the support shaft 26. The rotor magnet 33 is an even number of permanent magnets, for example, four or eight sets of permanent magnets, and an even number of permanent magnets in which magnetic field directions are inward and magnetic field directions are alternately arranged. It consists of a magnet.

  The stator 23 includes a silicon steel sheet laminate (magnetic body) and a plurality of sets of coils 24 wound around the plurality of slots to form a plurality of poles. A rotating magnetic field is generated by switching energization of the plurality of sets of coils 24, and the impeller 14 is rotated via the rotor magnet 33 and the outer rotor cup 30. Further, since a uniform magnetic force acts on the stator 23 from the rotor magnet 33 over the entire circumference, normally, a neutral posture in which the axis of the rotating shaft 32 coincides with the axis of the support shaft 26 is maintained.

  The outer peripheral surface of the stator 23 is formed in a partial spherical surface so as to face the inner surface of the rotor magnet 33 with a small gap. For example, eight integral leg members 25 made of synthetic resin that support the outer peripheral portion of the stator 23 and a cylindrical member 22 made of synthetic resin that supports the inner peripheral portion of the stator 23 are fixed to the base plate 21. . The cylindrical member 22 has an inner diameter larger than that of the rotation shaft 32, and is configured not to interfere with the rotation shaft 32 even when the rotation shaft 32 swings around the tip of the conical portion 26 a of the support shaft 26. A synthetic resin sleeve 26 a is fitted on the support shaft 26.

The operation and effect of the fan motor 10 described above will be described.
In the fan motor 10, the rotating shaft 32 is fixed to the axial center portion of the outer rotor cup 30, and the tip end portion of the rotating shaft 32 is positioned at the center of the partial spherical surface that forms the outer surface of the peripheral wall portion 30 a of the outer rotor cup 30. Since the tip of the support shaft 26 fixed to the base plate 21 is received and supported by point contact, bearing components that change with time such as ball bearings and sliding bearings are omitted, and the bearing structure is simplified, downsized, and durable. Can be increased.

  An annular rotor magnet 33 is fixed to the inner surface of the peripheral wall portion 30 a of the outer rotor cup 30, and magnetic force acts equally between the rotor magnet 33 and the annular magnetic body of the stator 23, so the outer rotor cup 30 The rotor magnet 33, the rotating shaft 32, and the impeller 14 are always maintained in a neutral posture that coincides with the axis of the support shaft 26.

  As described above, since the tip end portion of the rotating shaft 32 is supported by the support shaft 26 by point contact at the position of the center of the sphere, the external force acting on the impeller 14 in the direction orthogonal to the axial center is even over the entire circumference. In some cases, the impeller 14, the outer rotor cup 30, the rotor magnet 33, and the rotating shaft 32 may swing around the point contact portion as a swing center.

  However, at least the outer surface of the outer wall portion 30a of the outer rotor cup 30 is formed into a partial spherical surface that is centered on a point on the axial center of the impeller 14 and decreases in diameter toward the suction port 12 side of the casing 11. Since there is a small gap between the inner surface of the partial spherical surface and the outer peripheral surface of the partial spherical surface of the stator 23, even if the impeller 14, the outer rotor cup 30, the rotor magnet 30 and the like swing as described above, these Does not interfere with the stator 23. In other words, the outer surface of the peripheral wall 30a of the outer rotor cup 30 is a partial spherical surface, the inner surface of the rotor magnet 30 is a partial spherical surface, and the outer peripheral surface of the stator 23 is a partial spherical surface. A configuration that supports a single point is now possible.

  Since the outer surface of the rotor magnet 33 is formed into a partial spherical surface that is in close contact with the inner surface of the peripheral wall portion 30a of the outer rotor cup 30, the annular rotor magnet 33 is in close contact with the inner surface of the peripheral wall portion 30a and fixed with screws or an adhesive. can do. Since the tip of the outer rotor cup 30 on the suction port 12 side of the casing 11 is formed on the flat wall 30b, the diameter of the outer rotor type motor 20 can be formed larger than the length of the impeller 14 in the axial direction. .

  In the water heater 1 (heat source machine) provided with this fan motor, the fan motor 10 does not employ bearing parts that increase the frictional resistance due to aging, so that it has excellent durability and the amount of combustion air. The air amount control for controlling the air flow becomes simple.

Next, the fan motor 10A of Example 2 will be described.
However, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different configurations are described. As shown in FIG. 5, in the outer rotor type motor 20A of the fan motor 10A, the distal end portion 30E on the inlet 12 side of the casing 11 of the outer rotor cup 30A is continuously connected to the peripheral wall portion 30a of the outer rotor cup 30A. It is formed on a partial spherical wall. Therefore, the guide performance for guiding the air sucked from the suction port is excellent, and the swing angle when the impeller 14 or the like swings around the tip of the support shaft 26 can be increased.

  In the first and second embodiments, the fan motors 10 and 10A applied to the water heater 1 have been described as examples. However, the fan motor according to the present invention is a variety of fans provided in various devices and apparatuses other than the water heater. Applicable to motors. Moreover, the attitude | position which installs a fan motor is not limited to the attitude | position of the said Example, It can install in a various attitude | position.

It is a front view of the principal part of the hot-water supply apparatus which concerns on Example 1 of this invention. It is a front view of the fan motor incorporated in the hot water supply apparatus. It is the III-III sectional view taken on the line of FIG. It is a principal part enlarged view of a part of rotating shaft and a support shaft. FIG. 6 is a view corresponding to FIG. 3 of the fan motor according to the second embodiment.

Explanation of symbols

1 Water heater
10, 10A Fan motor 11 Casing 12 Suction port 13 Discharge port 14 Impeller 14a Blade 21 Base plate 23 Stator 24 Coil 26 Support shaft 30 Outer rotor cup 30a Peripheral wall portion 30b Flat wall 30E Tip portion 32 Rotating shaft 33 Rotor magnet

Claims (5)

In a fan motor having a casing having a suction port and a discharge port, an impeller housed in the casing and having a plurality of blades, and an outer rotor type motor that is mostly disposed inside the impeller.
The outer rotor type motor includes an outer rotor cup that is integrally fixed to an impeller, a rotary shaft that is fixed to an axial center portion of the outer rotor cup, and an annular rotor that is fixed to an inner surface of a peripheral wall portion of the outer rotor cup. Having a magnet and a stator having a plurality of sets of coils;
The outer surface of at least the peripheral wall portion of the outer rotor cup is formed in a partial spherical surface whose diameter is reduced as it moves to the suction port side of the casing with the point on the axial center of the impeller as the center,
A support shaft that supports the tip of the rotating shaft by point contact at the center of the partial spherical surface is provided concentrically with the rotating shaft,
A fan motor characterized in that a base end portion of the support shaft is fixed and a base plate for supporting the stator is fixedly provided on the casing.   2. The fan motor according to claim 1, wherein an outer surface of the rotor magnet is formed on a partial spherical surface that is in close contact with an inner surface of a peripheral wall portion of the outer rotor cup.   The fan motor according to claim 1 or 2, wherein a tip of the outer rotor cup on a suction port side of the casing is formed on a flat wall.   3. The fan motor according to claim 1, wherein a tip portion of the outer rotor cup on a suction port side of the casing is formed on a partial spherical wall continuously connected to the peripheral wall portion.   A heat source machine comprising the fan motor according to any one of claims 1 to 4.