阅读说明：本技术 排水泵用电动机及其制造方法以及具有该电动机的排水泵 (Motor for drain pump, method for manufacturing the same, and drain pump having the same ) 是由 佐藤克司 佐藤永 于 2018-10-16 设计创作，主要内容包括：提供一种能够有效地抑制在将轴承安装于树脂成形品的结构中产生的轴偏差的排水泵用电动机及其制造方法以及具有该电动机的排水泵。排水泵(1)的电动机(100)在定子(120)所具有的树脂制的定子模制件(121)埋入有金属制的定子芯(126)。定子模制件(121)嵌入在金属制的电动机罩(150)的外侧周壁部(152)的内侧。并且,定子芯(126)在定子模制件(121)的外周面露出且与电动机罩(150)的外侧周壁部(152)抵接。(Provided are a motor for a drain pump, a manufacturing method thereof and a drain pump having the motor, wherein the motor can effectively restrain the shaft deviation generated in the structure that a bearing is installed on a resin forming product. In a motor (100) of a drain pump (1), a metal stator core (126) is embedded in a resin stator molding (121) of a stator (120). The stator mold (121) is fitted inside the outer peripheral wall (152) of a metal motor cover (150). The stator core (126) is exposed on the outer peripheral surface of the stator mold (121) and abuts against the outer peripheral wall (152) of the motor cover (150).)

1. A drain pump motor for a drain pump, comprising:

a stator having a stator molding made of resin;

a metal motor cover having a peripheral wall portion, the stator mold being fitted inside the peripheral wall portion;

a stator-side bearing mounted to the stator;

a cover-side bearing mounted to the motor cover; and

a rotor supported by the stator-side bearing and the cover-side bearing,

a stator core made of metal is embedded in the stator molding,

the stator core is exposed on the outer peripheral surface of the stator mold and abuts against the peripheral wall portion of the motor cover.

2. The motor for a drain pump according to claim 1,

the stator core and a metal holding member for holding the stator-side bearing are embedded in the stator molding.

3. A drain pump, comprising:

the motor for the drain pump according to claim 1 or 2;

a rotary blade driven by the motor for the drainage pump to rotate; and

a housing containing the rotating blades.

4. A method for manufacturing a motor for a drain pump, which is a method for manufacturing a motor for a drain pump,

a stator mold is molded by embedding a metallic stator core in a resin stator mold provided in a stator so as to expose an outer peripheral surface of the stator mold,

mounting a stator side bearing to the stator molding,

the cover side bearing is mounted on a metal motor cover,

the stator-side bearing and the cover-side bearing support a rotor,

the stator mold is fitted inside the peripheral wall portion of the motor cover so that the peripheral wall portion abuts against the stator core.

5. The manufacturing method of a motor for a drain pump according to claim 4,

the stator mold is formed by embedding the stator core and a metal holding member holding the stator-side bearing in the stator mold.

6. The manufacturing method of a motor for a drain pump according to claim 5,

the holding member and the stator core are disposed in a cavity provided in one metal mold, and the cavity is filled with a resin to mold the stator mold in a state where the holding member and the stator core are respectively in contact with positioning surfaces in the metal mold along a rotation axis direction.

Technical Field

The present invention relates to a motor for a drain pump, a method of manufacturing the same, and a drain pump having the same.

Background

An air conditioner installed on a ceiling of an indoor room includes a drain pan for receiving condensed water condensed on a surface of an indoor heat exchanger, and a drain pump (condensed water pump) for draining the condensed water in the drain pan.

Patent document 1 discloses an example of a conventional drain pump. The drain pump has a motor portion and a pump portion. The motor unit includes a stator circuit unit formed by embedding a stator unit in a resin mold unit. The stator circuit portion has a through hole. A pair of upper and lower bearing assemblies are disposed in the through hole. A rotor is disposed between the bearing assemblies, and a drive shaft of the rotor is supported by the bearing assemblies. An impeller (rotary vane) of the pump section is mounted at a drive shaft of the rotor

Disclosure of Invention

Accordingly, an object of the present invention is to provide a motor for a drain pump, a method of manufacturing the same, and a drain pump having the same, which can effectively suppress the occurrence of shaft misalignment in a structure in which a bearing is mounted on a resin molded product.

Means for solving the problems

In order to solve the above problem, a motor for a drain pump according to an embodiment of the present invention includes: a stator having a stator molding made of resin; a metal motor cover having a peripheral wall portion, the stator mold being fitted inside the peripheral wall portion; a stator-side bearing mounted to the stator; a cover-side bearing mounted to the motor cover; and a rotor that is supported by the stator-side bearing and the cover-side bearing, wherein a metallic stator core is embedded in the stator mold, and the stator core is exposed on an outer peripheral surface of the stator mold and abuts against a peripheral wall portion of the motor cover.

In the present invention, it is preferable that the stator core and a metal holding member holding the stator-side bearing are embedded in the stator mold.

In order to solve the above problem, a drain pump according to another embodiment of the present invention includes: the electric motor for the drain pump; a rotary blade driven by the motor for the drainage pump to rotate; and a housing accommodating the rotary blade.

In order to solve the above problem, a method of manufacturing a motor for a drain pump according to another embodiment of the present invention is characterized in that a metal stator core is embedded in a resin stator mold provided in a stator so as to be exposed on an outer peripheral surface of the stator mold to form the stator mold, a stator-side bearing is attached to the stator mold, a cover-side bearing is attached to a metal motor cover, the stator-side bearing and the cover-side bearing support a rotor, and the stator mold is fitted inside a peripheral wall portion of the motor cover so as to be in contact with the stator core.

In the present invention, it is preferable that the stator mold is formed by embedding the stator core and a metal holding member that holds the stator-side bearing in the stator mold.

In the present invention, it is preferable that the holding member and the stator core are provided in a cavity provided in one metal mold, and the cavity is filled with a resin to mold the stator mold in a state where the holding member and the stator core are respectively in contact with positioning surfaces in the metal mold along a rotation axis direction.

Effects of the invention

According to the present invention, the resin stator mold of the stator is embedded with the metal stator core and is fitted inside the peripheral wall portion of the metal motor cover. The stator core is exposed on the outer peripheral surface of the stator mold and abuts against the peripheral wall portion of the motor cover. Thus, the metal stator core abuts against the peripheral wall portion of the motor cover, and resin deformation due to insertion can be suppressed. Therefore, the shaft misalignment between the stator-side bearing mounted on the stator mold, which is a resin molded product, and the housing-side bearing mounted on the motor housing can be effectively suppressed.

Drawings

Fig. 1 is a diagram showing a drain pump according to an embodiment of the present invention.

Fig. 2 is a sectional view taken along line a-a of fig. 1.

Fig. 3 is a view showing a motor included in the drain pump of fig. 1.

Fig. 4 is a sectional view of the motor of fig. 3 in an exploded state.

Fig. 5 is a sectional view illustrating a method of manufacturing the motor of fig. 3.

Fig. 6 is a diagram showing a configuration of a modification of the motor of fig. 3.

Detailed Description

The structure of a drain pump according to an embodiment of the present invention will be described below with reference to fig. 1 to 4. As an example, the drain pump of the present embodiment is used to discharge condensed water accumulated in a drain pan of an indoor unit of an air conditioner to the outside. Of course, the use of the drain pump is not limited to the drainage of the condensed water, and the drain pump can be used for drainage, pumping, and the like of various liquids.

Fig. 1 (a) is a front view of a drain pump according to an embodiment of the present invention, and fig. 1 (b) is a plan view. Fig. 2 is a sectional view taken along line a-a of fig. 1. Fig. 3 shows a motor included in the drain pump of fig. 1, in which fig. 3 (a) is a plan view and fig. 3 (B) is a cross-sectional view taken along line B-B of fig. 3 (a). Fig. 4 is a cross-sectional view (vertical cross-sectional view) taken along the rotation axis of fig. 3 with the motor exploded.

As shown in fig. 1 and 2, the drain pump 1 of the present embodiment has a housing 10, a cover 20, a rotary vane 30, and a motor 100. In the present embodiment, the casing 10, the cover 20, and the rotary blade 30 are made of synthetic resin.

The housing 10 integrally includes a body portion 11, a suction pipe 16, and a discharge pipe 18, the body portion 11 includes a bottom wall portion 12 having an inverted truncated cone shape and a peripheral wall portion 13 continuously provided on an outer peripheral edge of the bottom wall portion 12, the suction pipe 16 extends downward from a center of the bottom wall portion 12 and has a suction port 17 facing downward, the discharge pipe 18 extends laterally (in a left direction in fig. 1) from the peripheral wall portion 13 and has a discharge port 19 facing laterally, in the present embodiment, the discharge pipe 18 extends linearly laterally, but is not limited thereto, and may be formed in a substantially L shape or an arc shape with the discharge port facing upward, for example, a discharge pipe inlet 15 serving as an inlet to the discharge pipe 18 is provided on an inner peripheral surface 14 of the peripheral wall portion 13 of the body portion 11.

The casing 10 has a space in which the rotary vane 30 is disposed inside, and the casing 10 forms (partitions) the pump chamber 25 by surrounding the space together with the cover 20.

The cover 20 has a substantially cylindrical shape, and the lower end thereof is fitted into the upper opening of the body 11 of the housing 10 and is attached to the housing 10 through the locking portion 21. A bracket 23 is attached to the upper end of the cover 20 via an engaging portion 22. The bracket 23 is provided with a mounting portion 24 for mounting the drain pump 1 to another device.

The rotary vane 30 is rotatably accommodated in the pump chamber 25. The rotary vane 30 includes a shaft 31, a large-diameter vane 33, a small-diameter vane 34, and an annular portion 36. The rotary vane 30 includes a plurality of large-diameter vanes 33 and small-diameter vanes 34 formed in a substantially flat plate shape, and in the present embodiment, there are four large-diameter vanes 33 and four small-diameter vanes 34.

The shaft portion 31 is formed in a cylindrical shape, and has a mounting hole 32 at an upper end portion thereof, into which a drive shaft 144 of the motor 100 is fitted. The shaft 31 is inserted through the through hole 26 of the cover 20. The plurality of large-diameter blades 33 extend in the radial direction (radial direction) from the outer peripheral surface of the shaft portion 31. The plurality of small-diameter blades 34 are connected to the radially inner portion of the lower end of each large-diameter blade 33. The annular portion 36 has an inverted truncated cone shape, and is provided with an opening 37 at the center. The annular portion 36 connects the tapered portions of the lower ends of the large-diameter blades 33 to each other. The large-diameter vanes 33 are disposed in the pump chamber 25 such that the radially outer ends thereof face the inner circumferential surface 14 of the circumferential wall 13 of the housing 10. The small-diameter vane 34 is inserted into the suction pipe 16 through the opening 37 of the annular portion 36.

The motor 100 as a drain pump motor is accommodated in the cover 20. The motor 100 includes a stator 120, a rotor 140, a motor cover 150, a stator-side bearing 161, and a cover-side bearing 162.

Fig. 3 (a) and (b) are a plan view and a longitudinal sectional view of the motor 100. The stator 120 includes a stator mold 121 which is a resin molded product. The stator mold 121 integrally includes a substantially disk-shaped upper wall portion 122, a peripheral wall portion 123 extending downward from the peripheral edge of the upper wall portion 122, and a connector portion 124 projecting laterally from the upper wall portion 122. The metal cylindrical holding member 125 that holds the stator-side bearing 161 is embedded in the center of the upper wall portion 122 by insert molding. The circuit board 129 is also embedded in the upper wall 122 by insert molding. The end of the opening of the holding member 125 faces downward. The bobbin 127 integrated with the stator core 126 formed by laminating metal plates is embedded in the peripheral wall 123 by insert molding in a state wound in a coil shape by a copper wire. A radially outward surface 126a of the stator core 126 is exposed in the same plane as the outer peripheral surface of the peripheral wall 123. The wiring 128 is connected to the connector portion 124. The wire 128 supplies current to the copper wire wound around the bobbin 127 to excite the stator core 126.

The rotor 140 has a substantially disc-shaped magnet portion 141 having a magnet. The metal drive shaft 144 is fixed to the center of the magnet portion 141 so as to penetrate the magnet portion 141. The driving shaft 144 is rotatably supported by the stator-side bearing 161 at a position above the magnet portion 141. A portion of the drive shaft 144 below the magnet portion 141 is rotatably supported by the cover-side bearing 162. The magnet portion 141 is disposed to face the stator core 126 of the stator 120 with a space in the radial direction. The rotor 140 is driven to rotate by a magnetic force acting on the stator core 126 of the magnet portion 141.

The motor case 150 is made of a non-magnetic metal, and has a substantially annular plate-shaped bottom wall portion 151, an outer peripheral wall portion 152 provided continuously on an outer peripheral edge of the bottom wall portion 151, and an inner peripheral wall portion 153 provided continuously on an inner peripheral edge of the bottom wall portion 151. The motor cover 150 is a member obtained by press-working a sheet metal using a press die, for example, and has high dimensional accuracy. The peripheral wall 123 of the stator mold 121 is fitted inside the outer peripheral wall 152.

The stator-side bearing 161 and the cover-side bearing 162 are oil-impregnated bearings in which, for example, metal powder is compacted and sintered and then impregnated with oil, and the stator-side bearing 161 and the cover-side bearing 162 are each formed into a substantially cylindrical shape. The stator-side bearing 161 is press-fitted into the holding member 125 of the stator 120. The cover-side bearing 162 is press-fitted into the inner peripheral wall 153 of the motor cover 150. As the stator-side bearing 161 and the cover-side bearing 162, a ball bearing (ball bearing) may be used instead of the oil bearing. In the structure using the ball bearing, the holding member 125 may be omitted.

Next, an example of a method for manufacturing the electric motor for a drain pump according to the present embodiment will be described with reference to fig. 5. Fig. 5 is a longitudinal sectional view illustrating a method of manufacturing the motor 100 of the present embodiment.

First, the stator mold 121 is injection molded using the molds (the lower mold K1 and the upper mold K2) shown in fig. 5a, the lower mold K1 is a separable mold formed by combining a plurality of mold portions, or is a single (single) mold, as shown in fig. 5 b, the holding member 125, the bobbin 127 integrated with the stator core 126, and the circuit board 129 are disposed in the cavity C1 provided in the lower mold K1, and at this time, the inner peripheral surface 125a of the holding member 125 is brought into contact with the holding member positioning surface K11 along the direction of the rotation shaft L in the lower mold K1, the radially outward surface 126a of the stator core 126 is brought into contact with the stator core positioning surface K12 along the direction of the rotation shaft L in the lower mold K1, and thereby, the dimensional accuracy of the lower mold K1 of the holding member 125 and the stator core 126 is positioned in the radial direction as shown in fig. 5C, the lower mold K1 is opened, and the radially outer peripheral surface of the stator mold K898 is taken out, and the stator mold 121 is taken out as shown in fig. 7.

Next, the stator-side bearing 161 is press-fitted and attached to the holding member 125 of the stator mold 121. The cover-side bearing 162 is press-fitted and attached to the inner peripheral wall 153 of the motor cover 150. Then, the upper end portion of the drive shaft 144 of the rotor 140 is inserted into the stator-side bearing 161, and the lower end portion of the drive shaft 144 is inserted into the cover-side bearing 162, so that the rotor 140 is rotatably supported.

Then, the peripheral wall portion 123 of the stator mold 121 is fitted inside the outer peripheral wall portion 152 of the motor cover 150. At this time, the radially outward surface 126a of the stator core 126 abuts against the inner circumferential surface 152a of the outer circumferential wall portion 152, and the metal portions abut against each other, thereby suppressing deformation of the resin due to the insertion. This ensures the following distance accuracy: a radial distance D1 between the inner peripheral surface 125a of the holding member 125 and the radially outward surface 126a of the stator core 126, and a radial distance D2 between the inner peripheral surface 152a of the outer peripheral wall portion 152 of the motor cover 150 and the inner peripheral surface 153a of the inner peripheral wall portion 153. Therefore, the axial center of the stator-side bearing 161 attached to the holding member 125 can be aligned with the axial center of the cover-side bearing 162 attached to the inner peripheral wall 153 of the motor cover 150 with high accuracy, and these axial deviations can be suppressed.

As described above, according to drain pump 1 of the present embodiment, stator core 126 made of metal is embedded in stator mold 121 made of resin, which stator 120 of motor 100 has, and stator mold 121 is embedded inside outer peripheral wall portion 152 of motor cover 150 made of metal. The stator core 126 is exposed on the outer peripheral surface of the stator mold 121 and abuts against the outer peripheral wall portion 152 of the motor cover 150. Accordingly, the metal stator core 126 abuts against the outer peripheral wall portion 152 of the motor cover 150, and deformation of the resin due to the fitting can be suppressed. Therefore, the shaft misalignment between the stator-side bearing 161 attached to the stator mold 121 of the resin molded product and the cover-side bearing 162 attached to the motor cover 150 can be effectively suppressed.

Further, the stator core 126 and the metal holding member 125 that holds the stator-side bearing 161 are embedded in the stator mold 121. This can suppress resin deformation when the stator side bearing 161 is mounted on the stator mold 121, and can more effectively suppress shaft misalignment. Further, the holding member 125 can prevent the stator-side bearing 161 and the stator mold 121 from coming into direct contact with each other, and can suppress the deterioration of the resin due to the oil.

Further, the holding member 125 and the stator core 126 are disposed in the cavity C1 provided in the one lower die K1, and are brought into contact with the holding member positioning surface K11 and the stator core positioning surface K12 in the direction along the rotation shaft L in the lower die K1, respectively, and then, the resin is filled in the cavity C1 in this state to mold the stator mold 121, whereby the holding member 125 and the stator core 126 are positioned in the radial direction with the dimensional accuracy of the lower die K1, and therefore, the accuracy of the radial distance D1 between the inner peripheral surface 125a of the holding member 125 and the surface 126a of the stator core 126 facing the radial outer side can be effectively ensured.

The motor 100 of the drain pump 1 according to the embodiment has a structure in which the cover-side bearing 162, which is a single oil-retaining bearing, is provided on the inner peripheral wall 153 of the motor cover 150. For example, as shown in fig. 6, instead of the above-described housing-side bearing 162, a motor 100A having a configuration of a housing-side bearing 170 may be employed, the housing-side bearing 170 being a bearing unit composed of a plurality of members. Fig. 6 shows a motor 100A according to a modification of the above embodiment, in which fig. 6 (a) is a plan view and fig. 6 (b) is a cross-sectional view taken along line C-C of fig. 6 (a). In fig. 6, the same components as those in the above embodiment are denoted by the same reference numerals. The cover-side bearing 170 included in the motor 100A includes a metal housing 171, an oil-impregnated bearing 172 accommodated in the housing 171, and a pressure plate 173 for pressing the oil-impregnated bearing 172 against the housing 171. The cover-side bearing 170 is fitted into the inner peripheral wall 153 of the motor cover 150. In the housing-side bearing 170, the oil-impregnated bearing 172 is housed in the housing 171, whereby the coaxiality between the two bearings can be easily obtained as compared with the structure of the bearing alone such as the housing-side bearing 162 of the above-described embodiment. The motor 100A also exhibits the same effects as those of the above-described embodiment.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. In the above-described embodiments, those skilled in the art can appropriately add, delete, and change the design of the components and appropriately combine the features of the embodiments, and the configuration is included in the scope of the present invention as long as the gist of the present invention is achieved.

Description of the symbols

1 drain pump, 10 casing, 11 body, 12 bottom wall, 13 peripheral wall, 14 inner peripheral surface, 15 discharge pipe inlet, 16 suction pipe, 17 suction inlet, 18 discharge pipe, 19 discharge port, 20 cover, 21 snap part, 22 latch part, 23 bracket, 24 mounting part, 25 pump chamber, 26 through hole, 30 rotating blade, 31 shaft, 32 mounting hole, 33 large diameter blade, 34 small diameter blade, 36 ring part, 37 opening, 100A motor, 120 stator, 121 stator molding, 122 upper wall, 123 peripheral wall, 124 connector part, 125 holding member, 125a inner peripheral surface, 126 stator core, 126a surface facing radially outside, 127 bobbin, 128 wiring, 140 rotor, 141 magnet part, 144 drive shaft, 150 motor cover, 151 bottom wall, 152 outer peripheral wall, 152a inner peripheral wall, 153a inner peripheral surface, 161 stator side bearing, 162 cover bearing, 170 cover, 171 casing, 172 oil-containing bearing, 173 pressure plate, rotating shaft, D radial distance, K lower metal mold, K holding member, K upper metal core positioning surface, K side metal positioning surface, J metal positioning mold, K positioning surface, and J metal positioning mold