JP2015033208A - Motor and blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide compact and highly economic motor and blower in which reduction in motor output can be minimized while preventing leakage of high temperature and high pressure fluid.SOLUTION: A motor consists of a rotating shaft, a rotor fixed to the rotating shaft, a stator arranged to face the rotor on the circumference, bearings for supporting the rotating shaft rotatably on both sides of the rotor, a housing having an internal space for housing the rotating shaft, the rotor and the stator, and holding the stator and the bearings, and a thin plate member arranged in the internal space of the housing in tight contact with the inner peripheral part of the stator by receiving a pressure.

Description

  The present invention relates to a motor and a blower.

  The rotor of the motor is disposed at the shaft end opposite to the impeller of the rotating shaft by cantilever support in the bearing box, and the stator of the motor disposed in a non-contact state with the rotor on the outer periphery of the rotor is the bearing box. A sealing flange is disposed at the end of the bearing box opposite to the impeller, and a heat sink for cooling the bearing box is disposed directly or via the sealing flange. A fan for blowing high-temperature fuel gas in a solid oxide fuel cell is known (Patent Document 1).

Japanese Patent No. 5001665

  SUMMARY OF THE INVENTION An object of the present invention is to provide a small and highly economical motor and blower capable of suppressing a decrease in output of a motor while preventing leakage of a high-temperature and high-pressure fluid.

In order to solve the above problem, the motor according to claim 1 is:
A rotation axis;
A rotor fixed to the rotating shaft;
A stator disposed on the circumference facing the rotor;
A bearing rotatably supporting the rotating shaft on both sides of the rotor;
A housing having an internal space for housing the rotating shaft, the rotor, and the stator, and holding the stator and the bearing;
A thin plate member that receives pressure on the internal space of the housing and is placed in close contact with the inner peripheral portion of the stator.
It is characterized by that.

According to a second aspect of the present invention, in the motor according to the first aspect,
The pressure is 0.2% proof stress or less of the thin plate member,
It is characterized by that.

The invention according to claim 3 is the motor according to claim 1,
When the pressure exceeds the 0.2% proof stress of the thin plate member, the surface of the thin plate member facing the gap between the respective tooth portions arranged in the circumferential direction of the inner peripheral portion of the stator is plastically deformed. fixed,
It is characterized by that.

According to a fourth aspect of the present invention, in the motor according to any one of the first to third aspects,
The thin plate member is made of a nonmagnetic material,
It is characterized by that.

In order to solve the above-mentioned problem, the air blower according to claim 5
A motor according to any one of claims 1 to 4,
An impeller driven by the motor;
A casing for rotatably housing the impeller,
It is characterized by that.

According to the first aspect of the present invention, it is possible to suppress a decrease in the output of the motor while keeping the internal space for accommodating the stator airtight.
According to the second, third, and fourth aspects of the invention, the internal space that accommodates the stator is protected against high-temperature and high-pressure fluid while suppressing a decrease in the output of the motor as compared with the case where the present configuration is not provided. And can be kept airtight.
According to the fifth aspect of the present invention, it is possible to provide a small and highly economical air blower capable of suppressing a decrease in the output of the motor while preventing leakage of high temperature and high pressure fluid.

(A) is a schematic longitudinal cross-sectional view of the air blower 1, and (b) is a cross-sectional view of the air blower 10. (A) is a cross-sectional view of the motor unit 20, and (b) is a vertical cross-sectional view of the motor unit 20. (A) is a partial enlarged cross-sectional view for explaining a close contact state between the stator 50 and the partition wall 25, and (b) is a portion for explaining a state in which the partition wall 25 is plastically deformed and fixed to the opening G of the stator 50. It is an expanded sectional view. It is a schematic diagram explaining the process of determining the thickness of the partition 25 which received the pressure p from the inner surface (the rotor 22 side). It is a cross-sectional schematic diagram for demonstrating the movement of the fluid in the air blower. It is a longitudinal cross-sectional view of the air blower 100 of a comparative example. (A) is a longitudinal cross-sectional view of the air blower 200 of a comparative example, (b) is a longitudinal cross-sectional view of the air blower 300 of a comparative example.

Next, the present invention will be described in more detail with reference to the drawings with reference to the drawings. However, the present invention is not limited to these embodiments.
In the following description using the drawings, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones, and are necessary for the description for easy understanding. Illustrations other than the members are omitted as appropriate.

(1) Configuration of Blower Device FIG. 1A is a schematic longitudinal sectional view of the blower device 1 according to the present embodiment, and FIG. Hereinafter, the whole structure of the air blower 1 is demonstrated, referring drawings.
In each drawing, the partition wall 25 as an example of a thin plate member is shown thicker than the actual thickness for the sake of explanation.

  The blower device 1 includes a blower unit 10, a motor unit 20, a connection unit 30, and a control unit 40, and rotates the impeller 12 of the blower unit 10 connected to the motor unit 20 to suck from the suction port 13. The compressed fluid is compressed and discharged from the discharge port 14.

The blower unit 10 includes a casing 11 and an impeller 12 that is rotatably supported in the casing 11.
In the casing 11, a suction port 13 is formed in the central portion, and a discharge port 14 is formed in the outer periphery. The suction port 13 and the discharge port 14 are in communication with the casing 11.

The motor unit 20 is disposed on the side of the blower unit 10 and constitutes a brushless motor including a rotating shaft 21, a rotor 22, and a stator 50.
The impeller 12 is fixed to one end of the rotating shaft 21, and the rotor 22 is fixed to the other end side. The rotating shaft 21 is rotatably supported on the housing 24 via bearings 23 on both sides of the rotor 22.

The rotor 22 is formed of a magnetic material, and a permanent magnet 22a having a plurality of magnetic poles in the circumferential direction is embedded. Further, the isotropic multipole may be magnetized so as to have a plurality of magnetic poles in the circumferential direction without embedding the permanent magnet 22a.
The stator 50 has a gap on the outer peripheral side of the rotor 22 and is disposed to face the rotor 22.
In the gap between the rotor 22 and the stator 50, a partition wall 25 as an example of a thin plate member is fixed in close contact with the inner peripheral portion of the stator 50.

The connecting portion 30 includes a heat insulating plate 31 and an annular space portion 32, and one end of the casing 11 of the blower unit 10 and the motor unit with the one end side of the rotating shaft 21 inserted between the blower unit 10 and the motor unit 20. One end of each of the 20 housings 24 is connected via a heat insulating plate 31.
In addition, inside the annular space 32, the refrigerant supplied from the outside circulates, and heat transfer from the blower 10 to the motor unit 20 is suppressed.

  The control unit 40 includes a control board 41 (not shown) that performs power supply control to the stator 50, and is connected to an external power source (not shown) via wiring. The control board 41 has a semiconductor element such as an FET (field effect transistor) or a transistor, and supplies power supplied from an external power source to the stator 50 while performing switching control.

  In the air blower 1 configured as described above, electric power is supplied from the external power source to the stator 50 via the control unit 40, and the rotor 22 disposed so as to face the stator 50 and the partition wall 25 is rotationally driven. Then, the rotating shaft 21 with the rotor 22 fixed at one end rotates with the impeller 12, and the rotation of the impeller 12 sucks fluid into the casing 11 from the suction port 13, and compresses and boosts the sucked fluid. And discharged from the discharge port 14.

(2) Configuration of Motor Unit FIG. 2 (a) is a cross-sectional view of the motor unit 20, FIG. 2 (b) is a vertical cross-sectional view of the motor unit 20, and FIG. 3 (a) shows a close contact state between the stator 50 and the partition wall 25. FIG. 3B is a partially enlarged sectional view for explaining a state in which the partition wall 25 is plastically deformed and fixed to the opening G of the stator 50.
As shown in FIG. 2, the motor unit 20 includes a cylindrical rotor 22 and a stator 50 disposed opposite to the rotor 22 with a gap radially outward. In the gap between the rotor 22 and the stator 50, a partition wall 25 is fixed in close contact with the inner peripheral portion of the stator 50.

(2.1) Stator The stator 50 includes a stator core 51, an insulator 52 attached to both end faces of the stator core 51, and a coil 53 wound around the stator core 51 and the insulator 52.

The stator core 51 is made of laminated electromagnetic steel plates and has tooth portions 54 protruding radially inward, and the tooth portions 54 are arranged at equal intervals in the circumferential direction.
Between the adjacent tooth portions 54, the same number of slot portions 55 having openings G opened on the inner peripheral side (rotor 22 side) are formed.

The coil 53 is wound through an opening G that is open on the inner peripheral side of each slot 55 and sandwiches an insulator 52 that insulates the stator core 51 and the coil 53 around each tooth 54.
Although the number of the slot portions 55 is not particularly limited, in the blower device 1 according to the present embodiment, the stator 50 has nine slot portions 55, and the rotor 22 has six poles corresponding thereto. It is said that.

(2.2) Partition Wall As shown in FIG. 3A, the inner peripheral surface of the stator 50 has openings G formed at equal intervals in the circumferential direction between adjacent tooth portions 54 of the stator core 51.
The partition wall 25 is a cylindrical non-magnetic thin plate member made of, for example, non-magnetic stainless steel having a thickness of about 0.1 mm, and is fixed in close contact with the inner peripheral surface of the stator 50, and the opening G is formed from the inner peripheral surface. Arranged in a closed state.

As shown in FIG. 3B, the partition wall 25 is a housing that supports the stator 50 and the rotor 22 inside in a state where a cylindrical non-magnetic thin plate member is disposed in close contact with the inner peripheral surface of the stator 50. The inner space R of 24 may be fixed by being plastically deformed by applying a pressure p higher than the proof strength of the partition wall 25.
Specifically, the partition wall 25 receiving the pressure p from the inner surface (the rotor 22 side) is in close contact with the inner peripheral surface of the stator 50, and the region facing the opening G formed on the inner peripheral surface of the stator 50 is: It is fixed by being plastically deformed in a state where it receives the pressure p exceeding the proof stress and swells toward the opening G side.

(2.3) Determination of Plate Thickness of Partition Wall FIG. 4 is a schematic diagram for explaining the process of determining the thickness of the partition wall 25 that receives the pressure p from the inner surface (the rotor 22 side).
(2.3.1) When the pressure p is less than the yield strength of the partition wall 25 The partition wall 25 receives the pressure p from the inner surface and comes into close contact with the inner peripheral surface of the stator 50, and the opening G formed on the inner peripheral surface of the stator 50. The region opposite to is regarded as a thin cylindrical cylinder receiving pressure p, and the stress σ acting in the circumferential direction is expressed by the following formula (1) below the proof stress of the partition wall 25.
Circumferential stress: σ = pD / 2t (1)
However, in equation (1):
D is the opening width (cm) of the opening G, t is the thickness (cm) of the partition wall 25, and p is the pressure (kg / cm ² ) applied to the internal space R.

In the formula (1), the opening width D of the opening G = 1.0 cm, the pressure p = 20 kg / cm ² , and the 0.2% proof stress of the stainless steel material of the partition wall 25 is σ = 2000 kg / cm ^2. When the thickness is calculated, t = 0.005 cm = 0.05 mm.
That is, if a commercially available stainless steel thin plate having a standard thickness of 0.1 mm is used, the mechanical material strength is sufficient.

When the fluid is a high temperature / high pressure, for example, a heated fluid having a pressure p of about 2 MPa and a temperature of 300 ° C., the 0.2% proof stress of the stainless steel material of the partition wall 25 is σ = 1500 kg / cm ^2. As a result, when the thickness of the partition wall 25 is calculated, t = 0.0067 cm = 0.067 mm.
That is, even a high-temperature / high-pressure heating fluid has sufficient mechanical material strength if a commercially available stainless steel thin plate having a standard thickness of 0.1 mm is used.

(2.3.2) When the pressure p exceeds the yield strength of the partition wall 25 The partition wall 25 is subjected to a pressure p higher than the yield strength from the inner surface, and the region facing the opening G formed on the inner peripheral surface of the stator 50 is plasticized. The approximate value when it is deformed and fixed is expressed by the following equation (2).
^{p = E · [m 2/} 4 (m 2 -1)] · [8t 3 / D 3] ··· (2)
However, in equation (2):
D is the opening width (cm) of the opening G, t is the thickness (cm) of the partition wall 25, m is the Poisson's ratio, and E is the Young's modulus.

In the equation (2), when the opening width G of the opening G = 1.0 cm and the thickness t of the partition wall 25 = 0.01 cm = 0.1 mm and the pressure p is calculated, p = 40 MPa. The result is difficult to deform.
On the other hand, when the opening width D of the opening G is set to 2.0 cm and the opening width D of the opening G of the adjacent tooth portion 54 of the stator 50 is widened, p = 5 MPa, and the winding work of the coil 53 is facilitated. On the other hand, even with a high-temperature / high-pressure heating fluid, a sufficient mechanical material strength can be obtained by using a commercially available stainless steel thin plate having a standard thickness of 0.1 mm.

(2.4) Housing The housing 24 supports the stator 50 in which the partition wall 25 is in close contact with the inner peripheral surface to hold the high-temperature and high-pressure fluid in the inner space R, and on both sides of the rotor 22 the rotating shaft 21. Each of the bearings 23 is supported so as to be rotatably supported.
Further, a cable for supplying electric power to the coil 53 wound around the stator 50 is drawn out from one end of the outer peripheral surface of the housing 24.

(3) Action / Effect of Blower Device Before describing the action / effect of the blower device 1 according to the present embodiment, problems of the blower devices 100 and 200 of the comparative example will be described.

(3.1) Configuration and Operation of Blower Device 100 FIG. 6 is a longitudinal sectional view of a blower device 100 of a comparative example.
The blower device 100 includes a blower unit 110, a motor unit 120, a connecting unit 130, and a control unit 140.
An impeller 112 is fixed to one end of the rotating shaft 121, and a rotor 122 is fixed to the other end side. The rotating shaft 121 is rotatably supported by the housing 124 via bearings 123 on both sides of the rotor 122.

A seal member S selected from a gland packing, an oil seal, an O-ring, or the like is provided as a shaft seal member between the connecting portion 130 of the rotating shaft 121 and each bearing 123.
On the other hand, when the fluid sent out by the blower 100 is at a high temperature and high pressure, the material deteriorates in the gland packing, oil seal, O-ring, etc. mainly made of rubber or synthetic resin. There was a problem of short life.

  In particular, for example, the heating fluid used in the tire vulcanizer has the pressure p of about 2 MPa and the temperature reaches 300 ° C., so that the seal member S deteriorates in a short time and passes through the seal member S. High temperature and high pressure heating fluid may enter the stator 150 of the motor unit 120 (see the arrow in FIG. 6), and the coil may be damaged.

(3.2) Configuration and Operation of the Blowers 200 and 300 FIG. 7A is a longitudinal sectional view of the blower 200 of the comparative example, and FIG. 7B is a longitudinal sectional view of the blower 300 of the comparative example.
The blower device 200 includes a blower unit 210, a motor unit 220, and a control unit 240.
An impeller 212 is fixed to one end of the rotating shaft 221, and a rotor 222 is fixed to the other end, and both sides of the rotor 222 are rotatably supported by a housing 224 via respective bearings 223.
Between the rotor 222 and the stator 250, a bottomed resin partition 225 is disposed in a non-contact manner.

  In such a blower device 200, when the fluid to be delivered is at a high temperature and a high pressure, in particular, for example, when the pressure p is about 2 MPa and the temperature is 300 ° C., the thickness of the resin partition 225 is increased. It is necessary to thicken. Therefore, there is a problem that the gap between the rotor 222 and the stator 250 becomes large, resulting in a decrease in motor performance.

  In particular, in order to support the bearing 223 of the rotating shaft 221 to which the rotor 222 is fixed by disposing the resin partition 225 between the rotor 222 and the stator 250, the resin partition 225 serves as a housing. In order to ensure the mechanical strength, a larger wall thickness was required.

  In addition, as shown in FIG. 7B, the blower 300 supports the bearing 223 with a housing 224 of the motor unit 220. Therefore, it is necessary to dispose the respective bearings 223 between the rotor 222 and the impeller 212, and the connection part 230 between the motor part 220 and the air blowing part 210 becomes long, resulting in a problem that the air blowing device 300 is enlarged. there were.

(3.3) Action of the Blower 1 FIG. 5 is a schematic cross-sectional view for explaining the movement of fluid in the blower 1.
The blower device 1 according to the present embodiment constitutes a brushless motor in which the motor unit 20 is disposed on the side of the blower unit 10 and includes a rotating shaft 21, a rotor 22, and a stator 50.
The impeller 12 is fixed to one end of the rotating shaft 21, and the rotor 22 is fixed to the other end side. The rotating shaft 21 is rotatably supported on the housing 24 via bearings 23 on both sides of the rotor 22.

  In the gap between the rotor 22 and the stator 50, a partition wall 25 is fixed in close contact with the inner peripheral portion of the stator 50. The partition wall 25 is a cylindrical non-magnetic thin plate member, and is arranged in a state in which openings G formed at equal intervals between adjacent tooth portions 54 of the stator core 51 are closed from the inner peripheral surface.

In the air blower 1 configured as described above, the rotating shaft 21 having the rotor 22 fixed at one end rotates with the impeller 12, and the rotation of the impeller 12 causes the high temperature / high pressure from the suction port 13 to the casing 11. And the compressed fluid is further compressed and pressurized and discharged from the discharge port 14.
The compressed / pressurized high-temperature / high-pressure fluid is discharged from the discharge port 14, but part of the fluid passes through the connecting portion 30 from the insertion portion of the casing 11 and the rotating shaft 21. Then, the high-temperature and high-pressure fluid flows from the bearing 23 supported by the housing 24 to support the rotating shaft 21 to the internal space R of the housing 24 where the rotor 22 is supported (see the arrow in FIG. 5).

The inner space R of the housing 24 is in an airtight state because the partition wall 25 made of stainless steel having a thickness of 0.1 mm is closely attached to the inner peripheral surface of the stator 50 facing the rotor 22.
As a result, the high-temperature / high-pressure fluid that has flowed into the internal space R stays in the internal space R, and is in a pressurized state that is substantially equal to that in the casing 11 of the blower unit 10.
Therefore, the rotation shaft 21 and the rotor 22 can be sealed to prevent the motor performance from being lowered without widening the gap between the rotor 22 and the stator 50.

  Since the fluid that has once flown in the inner space R of the housing 24 in which the partition wall 25 is in close contact with the inner peripheral surface of the stator 50 and is in an airtight state, the fluid in the inner space R is not replaced. Even if the high-temperature heating fluid is continuously sent out by the part 10, the temperature rise in the internal space R is suppressed.

  The partition 25 is plastic in a state where a region facing the opening G formed on the inner peripheral surface of the stator 50 is bulged toward the opening G side by applying a pressure p higher than the proof strength of the partition 25 to the internal space R of the housing 24. In the deformed and fixed state, the rotating shaft 21 and the rotor 22 can be held as a sealed structure without widening the gap between the rotor 22 and the stator 50 even when a higher pressure fluid flows in.

  That is, the inner surface of the partition wall 25 is preliminarily plastically deformed by applying a pressure p equal to or higher than the maximum working pressure, and can be used as it is as the partition wall 25 having a sealed structure. The blower 1 having sufficient strength and including the internal space R of the sealed structure can be manufactured at a lower cost.

The rotary shaft 21 is rotatably supported by bearings 23 on both sides of the rotor 22, and the bearings 23 are held by a housing 24.
As a result, the support of the rotating shaft 21 with the impeller 12 fixed to the one end side and rotating is stabilized, and the blower device 1 including the motor unit 20 can be downsized and economically improved.

The blower 1 according to this embodiment can be suitably used as a blower in a tire vulcanizer that performs vulcanization by supplying a high-temperature, high-pressure inert gas to a bladder set on the inner surface of an unvulcanized tire. .
Moreover, it is also suitable as a blower for high temperature fuel gas recirculation of a stationary solid oxide fuel cell.

DESCRIPTION OF SYMBOLS 1, 100, 200, 300 ... Air blower 10, 110, 210 ... Air blower 11 ... Casing 12, 112, 212 ... Impeller 13 ... Inlet 14 ... Discharge 20 , 120, 220 ... motor part 21, 121, 221 ... rotating shaft 22, 122, 222 ... rotor 23, 123, 223 ... bearings 24, 124, 224 ... housing 25, 225, .., partition walls 30, 130, 230 ... connecting part 31 ... heat insulating plate 32 ... annular space part 40, 140, 240 ... control part 41 ... control board 50, 150, 250 ... Stator 51 ...
Stator core 52 ... Insulator 53 ... Coil 54 ... Teeth 55 ... Slot G ... Opening R ... Internal space S ... Sealing member

Claims (5)

A rotation axis;
A rotor fixed to the rotating shaft;
A stator disposed on the circumference facing the rotor;
A bearing rotatably supporting the rotating shaft on both sides of the rotor;
A housing having an internal space for housing the rotating shaft, the rotor, and the stator, and holding the stator and the bearing;
A thin plate member that receives pressure on the internal space of the housing and is placed in close contact with the inner peripheral portion of the stator.
A motor characterized by that. The pressure is 0.2% proof stress or less of the thin plate member,
The motor according to claim 1. When the pressure exceeds the 0.2% proof stress of the thin plate member, the surface of the thin plate member facing the gap between the respective tooth portions arranged in the circumferential direction of the inner peripheral portion of the stator is plastically deformed. fixed,
The motor according to claim 1. The thin plate member is made of a nonmagnetic material,
The motor according to any one of claims 1 to 3, wherein the motor is provided. A motor according to any one of claims 1 to 4,
An impeller driven by the motor;
A casing for rotatably housing the impeller,
A blower characterized by that.

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