JP3445975B2 - Pump for hot water circulation by direct drive of brushless DC motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump for circulating water by a direct drive of a brushless DC motor in the pump field.

[0002]

2. Description of the Related Art Conventionally, a so-called magnet pump has been used when it is necessary to completely partition a pump portion and a motor portion to reliably prevent water leakage from the pump portion to the motor portion.

As a drive system of this magnet pump, a sealless pump of a so-called magnet coupling is used in which a magnetic material is magnetically inductively coupled via a partition wall separating the pump portion and the motor portion.

In recent years, due to demands for downsizing, space saving, and the like, in the above sealless pump, the pump portion is larger than the motor portion and is fitted in the blade body which is the rotor of the motor inside the partition wall. There is known a direct drive of a brushless DC motor that drives by directly acting on the permanent magnet from the outside of the partition wall by induction of magnetic force. It is possible to improve efficiency by driving the DC motor and further downsize the pump. Is being carried out.

In this conventional brushless DC motor direct drive pump, a potting material such as urethane foam resin is hermetically sealed around the internal equipment in the cylindrical casing in order to further improve the water resistance of the internal equipment. In order to prevent deterioration of the quality of the magnetic induction drive unit and the printed circuit board, which are interior equipment, due to dew condensation inside the equipment when loaded, the interior equipment is insulated and heat-insulated.

[0006]

By the way, when the potting material is loaded around the interior equipment in the casing, the heat insulating property is increased to that extent, and conversely, there is a problem in the cooling property for preventing the equipment from heating. On the other hand, demand is increasing under high temperature and high humidity environmental conditions such as hot water supply and floor heating, and it is necessary to take more reliable insulation measures against dew condensation on the magnetic induction drive unit and the printed circuit board. The problem is to improve the durability of elements such as semiconductors by improving the cooling performance of the element.

[0007]

The present invention has been made in view of the above points, and in order to solve the above-mentioned problems, the means of the present invention has an outer casing and an inner casing. A centrifugal pump composed of a rotor of a brushless DC motor and a double-walled impeller directly driven by the rotor is provided inside the inner casing, and magnetic force induction drive of the brushless DC motor is provided inside an outer casing of the outer periphery of the inner casing. The internal parts of the inner casing such as a motor drive controller having a magnetic force sensor composed of a stator and a Hall element for inductively controlling the magnetic force of the stator are filled with potting material between the inner casing and the outer casing. Direct dry of a brushless DC motor in which the above-mentioned internal equipment is embedded in a potting material inside the outer casing In the pump for hot water circulation by,
The outer casing is divided into a main body casing part for enclosing the inner casing and a control casing part with an air-cooling cavity penetrating the center part of the outer casing behind the main body casing part. A motor drive control unit having a magnetic force sensor including a Hall element for inductively controlling the magnetic force of the stator is provided as a hall element of the main body casing section by providing a cooling cavity between the casing sections and integrally communicating with the connecting body section. The printed circuit board for motor drive control is separated from the printed circuit board for the magnetic force sensor by a lead wire connection to be housed in the control casing part, and the lead wire is inserted into the connecting body part, and between the inner casing and the outer casing of the main body casing part. And the space between the internal equipment inside the connecting body and inside the control casing as potting material It is a pump for circulating hot water by a direct drive of a brushless DC motor, characterized in that the potting material is isolated from the outside air by filling the interior equipment by burying it in one body and covering the loading port of the potting material with a lid. is there.

According to the second aspect of the present invention, the outer casing including the main body casing portion, the control casing portion, and the connecting body portions on the left and right sides of the cooling cavity portion is an integrally molded body of a lightweight metal material such as aluminum material. It is a pump for circulating hot water by a direct drive of the brushless DC motor according to the means of claim 1.

According to a third aspect of the present invention, the inner casing comprises a partition wall having a substantially U-shaped cross section in the central portion of the casing body, and the rotor in the inner casing is rotatably supported by a permanent magnet material. It consists of a vane body with an interior,
A stator for magnetic force induction driving of an internal brushless DC motor is arranged on the outer peripheral portion of the inner casing so as to face the magnet material of the vane body, and a printed circuit board for the magnetic sensor of the Hall element is provided outside the rear portion of the inner casing. A centrifugal pump, which is arranged in a casing and consists of an impeller directly driven by a rotor of a brushless DC motor, has a suction port in an outer casing which is coaxial with the front end side of the rotor and which is installed in a double-walled impeller. 3. A pump for circulating hot water by a direct drive of a brushless DC motor according to claim 1 or 2, wherein the pump has a discharge port for sending water from the axial center part to one outer circumferential part of the impeller to the outside of the outer casing.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a side view of a pump for circulating hot water by a direct drive of a brushless DC motor according to the present invention, the upper half of which is partially cut away to show the internal structure, and the lower half of which shows its appearance. FIG. 2 is a plan view showing a part of a main body casing of the hot water circulation pump of FIG. 1, a connecting body portion, a cooling cavity portion, and a control casing portion. FIG. 3 shows A of FIG.
-It is sectional drawing cut | disconnected by the A section and seen in the arrow direction.

As shown in FIG. 1, a pump 1 for circulating hot water by a direct drive of a brushless DC motor according to the first embodiment of the present invention, as shown in FIG. 1, has an outer casing 2 and an inner casing. 3, a centrifugal pump composed of a rotor 4 of a brushless DC motor and an impeller 5 composed of a double wall body directly driven by the rotor 4 is housed in an inner casing 3. On the other hand, a motor drive controller 7 having a stator 5 for magnetic force induction driving of a brushless DC motor and a magnetic force sensor including a Hall element for inductively controlling the magnetic force of the stator 5 inside the outer casing 2 on the outer periphery of the inner casing 3. Interior equipment such as. And these inner casings 3
A potting material 8 of urethane foam resin is filled between the outer casing 2 and the outer casing 2, and the above-mentioned internal equipment is embedded in the outer casing 2 at the outer peripheral portion of the inner casing 3 with the potting material 8 to directly connect the brushless DC motor. It is a pump 1 for circulating hot water by a drive.

In the embodiment of claim 1, particularly in the hot water circulation pump 1 by the direct drive of these brushless DC motors, the outer casing 2 and the main body casing portion 9 in which the inner casing 3 is housed are shown in FIG. As described above, it is divided into a control casing portion 15 formed by interposing an air-cooling hollow portion 10 penetrating the central portion of the outer casing 2 behind the main body casing portion 9. A cooling cavity portion 10 is provided between the main body casing portion 9 and the control casing portion 15 and is integrally communicated with the connecting body portion 11. For example, connecting body portions 11 are symmetrically arranged on the left and right of the hollow portion 10, and the connecting body portion 11 integrally connects the main body casing portion 9 and the control casing portion 15. Further, the motor drive control unit 7 having a magnetic force sensor including a Hall element for inductively controlling the magnetic force of the stator 6 is provided from the printed circuit board 12 for the magnetic force sensor of the Hall element of the main body casing unit 9 to the printed circuit board 13 for motor drive control.
2 and is housed in the control casing portion 15 by connecting the lead wire 14, and as shown in FIG.
The lead wire 14 is inserted through the connecting body portion 11 and connected to the printed circuit board 12 for the magnetic force sensor of the main body casing portion 9.

Then, a potting material made of urethane foam resin is provided between the inner casing 3 and the outer casing 2 of the main body casing portion 9, the inside of the connecting body portion 11 and the voids between the internal equipments in the control casing portion 15. Material 8
For example, the rear portion of the control casing portion 15 is opened, and the interior equipment is embedded by integrally loading from the opened portion. By embedding the devices with the potting material in this manner, even if the hot water circulation pump 1 of the present invention is used in a hot and humid environment, the inside of the outer casing 2 is thermally insulated, so that dew condensation occurs around the devices. As a result, the printed circuit board will not be damaged. The rear portion of the control casing portion 15, which is the loading port for the potting material 8, has a packing material of, for example, an O-ring 17 fitted therein and is covered with a lid body 16 to isolate the potting material 8 from the outside air. In this way, by blocking the potting material 8 from the outside air,
The urethane foam resin of the potting material 8 is prevented from being watered and gradually deteriorated.

By the way, in the invention according to claim 1, as described above, the potting material 8 made of urethane foam resin is used.
The devices inside the outer casing 2 are embedded and insulated, but the circuit of the motor drive control unit 7 having a magnetic force sensor composed of a Hall element for inductively controlling the magnetic force of the stator 6 by this thermal insulation effect. Dissipation of heat from semiconductor elements such as Hall elements of a printed circuit board, which is a substrate, which are weak against heat, is hindered, and as a result, these semiconductors may be destroyed. Therefore, in the invention of claim 1, the motor drive control section 7 is separated into the printed circuit board 12 for the magnetic sensor of the Hall element of the main body casing section 9 and the printed circuit board 13 for the motor drive control so that they do not affect each other. In addition, in order to easily cool the printed circuit board 12 and the printed circuit board 13, both of them are arranged in separate casings, and are also arranged near the metal wall bodies of these casings for easy cooling. Therefore, for this purpose, a control is provided in which a cavity 10 for air cooling is provided in the center behind the main body casing portion 9 and the left and right sides thereof are symmetrically connected by a connecting body portion 11 to accommodate the printed circuit board 13. The casing portion 15 is integrally formed.

In the present embodiment, the temperatures of the printed circuit board 12 and the printed circuit board 13 for controlling the motor drive can be lowered by about 10 to 15 ° C. as compared with the conventional example. In particular, the printed circuit board 12 of the magnetic sensor and the pump. Even if an IC or the like that is easily affected by temperature is mounted on the printed circuit board 13 for drive control, the performance can be stably exhibited.

Particularly, in the embodiment of the invention of claim 2,
By forming the main body casing part 9, the connecting body part 11 and the control casing part 15 from a lightweight metal material such as an aluminum alloy having excellent heat conductivity integrally by, for example, casting, the number of parts can be reduced. To reduce costs.

Further, in the third embodiment of the invention,
An inner casing 3 having a partition wall with a lateral U-shaped cross section is installed in the center of the outer casing 2, and a rotor 4 of a brushless DC motor pivotally supported in the inner casing 3 rotates on a rotating shaft 26. The permanent magnet 23 of the vane body 22 is provided with a stator 6 for freely magnetically driving a brushless DC motor, which is internally supported by a vane body 22 in which a permanent magnet 23 is incorporated. The printed circuit boards for the magnetic sensors of the Hall elements, which are arranged so as to face each other, are arranged inside the outer casing behind the inner casing. The centrifugal pump including an impeller 5 that is directly driven by the rotor 4 of the brushless DC motor is coaxial with the front end side of the rotor 4 and has an outer casing 2.
Has a suction port 20, and has a discharge port 21 that extends from the axial center portion of the double-walled impeller 5 to the outside of the outer casing 2 from one circumferential direction portion of the outer circumference of the impeller 5 and supplies water. Characterize.

The hot water circulation pump 1 by the direct drive of the brushless DC motor according to the embodiment of the present invention is
It is particularly suitable for high temperatures such as hot water supply and heating, for example, hot water used for floor heating is hot water of 80 to 90 ° C., and the DC motor has a wider range of flow rate control than the AC motor. Is always rotating, and if the motor has the same capacity, it may be overheated or, on the contrary, overheated due to the difference in the floor area of the installed room.
Since the C motor can control the flow rate, it can be controlled appropriately.

In the outer casing 2, as shown in FIG. 1, a main body casing portion 9 on the motor side and a pump side casing lid 19 made of, for example, plastic on the pump side are connected by screws 27. The suction port 20 of the pump is integrally formed on the pump-side casing lid 30, and the discharge port 21 of the pump in the centrifugal direction is also integrally formed on the pump-side casing lid 30. . Therefore, the pump 1 for hot water circulation by the direct drive of the brushless DC motor of the present invention is large, and its casing is made of a plastic pump side casing lid 19, a main body casing portion 9 made of an aluminum alloy, a connecting body portion 11, and a control. It is formed from three parts, that is, an integrally molded body of the casing 15 for control and a cover 16 at the rear end of the casing 15 for control, which has a small number of parts, a small number of assembling steps, and is excellent in cost.

As shown in the figure, the blade body 22 is formed with a notch at the inner end of the permanent magnet 23. A plurality of balance weights having a required weight are formed in the notch with a predetermined diameter about the rotary shaft 26. It is attached on the circumference so that the rotational balance condition of the blade body 22, that is, the rotor 4 can be adjusted.

As shown in FIGS. 1 and 2, the potting material 32 is injected by opening the lead wire outlet 29 and the lid 16 which are open at the end surface of the control casing 29, and the outer casing 2 and the inner casing 3 are then injected. In between, the connection body 11 and the control casing 15 can be integrally fluidized and filled.

In the present invention, since the cooling air can freely flow in the hollow portions 10 between the connecting body portions, the rear surface portion of the main body casing portion 9 and the front surface portion of the control casing portion 15 can be effectively cooled, For example, when used under high-temperature environmental conditions such as hot water supply and heating at a high temperature of 90 ° C., the printed circuit board portion and the like can be maintained at a predetermined temperature and durability can be improved.

In the above description, the sealless pump for hot water supply and heating has been described. However, not only the pump for circulating hot water but also the pump for other purposes can be applied based on the spirit of the present invention to improve the quality. The durability can be improved.

[0024]

As described above, according to the present invention, the casing of the pump for hot water circulation by the direct drive of the brushless DC motor comprises the outer casing, the inner casing portion, the connecting body portion, and the control casing portion. In particular, since a cavity for air cooling was formed between the connecting body parts,
The external casing and the control casing printed circuit board portion for controlling and driving the DC motor can be arranged in a divided manner, and can prevent thermal buffering from each other, and can be arranged close to the wall for air cooling. The semiconductors on the weak printed circuit board can be protected by cooling, and moreover, the potting material is loaded in three parts of the outer casing and the inner casing, the connecting body part, and the control casing part to install the magnetic induction drive unit, the printed circuit board unit, and other equipment. Since it is formed in a sealed state with potting material, even under high temperature and high humidity environments such as hot water supply, heating, etc., internal dew condensation does not occur in the magnetic induction drive unit and printed circuit board unit, etc. The durability can be improved.

Since the above-mentioned three parts are integrally formed, the number of parts can be reduced, the number of assembling steps can be reduced, and the cost can be reduced. In addition, since the casing of the main body is made of a lightweight aluminum alloy, the pump body can be made lightweight, and since the heat conductivity is good, the heat dissipation is also excellent.

[Brief description of drawings]

FIG. 1 shows the internal structure by cutting a part of the upper half,
The lower half shows a side view of a pump for hot water circulation by a direct drive of the brushless DC motor of the present invention showing its appearance.

FIG. 2 is a plan view showing a part of a main body casing of the hot water circulation pump of FIG. 1, a connecting body, a cooling cavity, and a control casing.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1 and viewed in the direction of the arrow.

[Explanation of symbols]

1 Hot water circulation pump 2 External casing 3 Inner casing 4 rotor 5 impeller 6 stator 7 Motor drive control unit 8 potting materials 9 Main body casing 10 cavity 11 Connection body 12 Printed circuit board 13 Printed circuit board 14 lead wire 15 Control casing 16 Lid 17 O-ring 18 Fins 19 Pump side cover 20 Suction port 21 Discharge port 22 vane body 23 Permanent magnet 24 core 25 coils 26 rotation axis 27 screws 28 Locking claw 29 Lead wire outlet

Continuation of front page (56) Reference JP-A-11-107972 (JP, A) JP-A-9-137794 (JP, A) JP-A-10-311290 (JP, A) JP-A-2000-240593 (JP, A) Actual Kaihei 3-102090 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F04D 13/02 F04D 29/58

Claims (3)

(57) [Claims] 1. A centrifugal pump having an outer casing and an inner casing, wherein a rotor of a brushless DC motor and a double-walled impeller driven directly by the rotor is provided inside the inner casing, and the outer periphery of the inner casing is included. In the outer casing of the unit, a motor drive controller having a magnetic force sensor including a stator for magnetic force induction driving of a brushless DC motor and a Hall element for inductively controlling the magnetic force of the stator is installed, and an internal casing is provided. In a pump for hot water circulation by a direct drive of a brushless DC motor, in which a potting material is filled between outer casings, and the above-mentioned internal equipment is embedded in the outer casing at the outer peripheral portion of the inner casing, the outer casing is provided inside. Main body casing part that houses the casing and main body casing part It is divided into a control casing part having an air-cooling cavity part penetrating the center part of the rear outer casing, and a cooling cavity part is provided between the main body casing part and the control casing part to form a connecting body part. The motor drive control unit that has a magnetic force sensor consisting of a Hall element for inductively controlling the magnetic force of the stator is connected from the printed circuit board for the magnetic force sensor of the Hall element of the main body casing to the printed circuit board for motor drive control. The lead wires are separated by a lead wire connection and housed in the control casing portion, and the lead wires are inserted into the connecting body portion, and the interior casings of the main body casing portion and between the outer casings, the interior of the connecting body portion and the control casing portion are installed. The interior space is buried by loading the space between them with potting material,
Also, a hot water circulating pump by a direct drive of a brushless DC motor, characterized in that the potting material charging port is covered with a lid to isolate the potting material from the outside air. 2. The outer casing, which is composed of a main body casing portion, a control casing portion, and left and right connecting body portions of the cooling cavity portion, is an integrally molded body of a lightweight metal material such as an aluminum material. A pump for circulating hot water by a direct drive of the brushless DC motor according to 1. 3. The inner casing comprises a partition wall having a substantially U-shaped cross section in the center of the casing body.
The rotor in the inner casing is composed of a vane body in which a rotatably supported permanent magnet material is installed, and the stator for magnetic force induction driving of a brushless DC motor provided in the outer periphery of the inner casing is a magnet material of the vane body. The printed circuit board for the magnetic sensor of the Hall element is disposed inside the outer casing at the rear of the inner casing, and the centrifugal pump composed of an impeller directly driven by the rotor of the brushless DC motor rotates. The front end side of the child has a suction port coaxially with the outer casing, and has a discharge port for sending water from the axial center part in the double-walled impeller to the outside of the outer casing from one circumferential direction part of the impeller outer periphery. A pump for hot water circulation by a direct drive of the brushless DC motor according to claim 1 or 2.