Pump, method for manufacturing pump, and refrigeration cycle device

Provided is a pump that includes an annular molded stator having a substrate mounted with a Hall element and that includes a rotor having an annular rotor unit rotatably housed in a cup-shaped partition component, with one end thereof in an axial direction facing the Hall element and the other end thereof in the axial direction provided with an impeller attachment unit. The rotor unit includes a resin magnet, a sleeve bearing, and a resin portion. The resin magnet includes a rotor-position detecting magnetic-pole portion protruding axially with a predetermined height in an annular shape having a predetermined width in a radial direction on an outer periphery of an end face opposite to the Hall element. The rotor-position detecting magnetic-pole portion includes a plurality of arc-shaped notches on the same circumference on an inner diameter side thereof.

CROSS REFERENCE TO RELATED APPLICATION

This application is a U.S. national stage application of International Patent Application No. PCT/JP2012/065636 filed on Jun. 19, 2012.

TECHNICAL FIELD

The present invention relates to a pump, a method for manufacturing the pump, and a refrigeration cycle device.

BACKGROUND

A pump has been provided that includes a rotor having a drive magnet unit and a position-detection magnet unit axially protruding from an end face of the drive magnet unit; a resin sealing portion that has an inner hole for housing the rotor and that seals the stator; a magnetic sensor arranged opposite to the vicinity of the position-detection magnet unit in order to detect the magnetic pole position of the position-detection magnet unit and that is housed in the resin sealing portion; and a pump casing that has a feed-water inlet and a drain outlet and that covers the resin sealing portion. The pump controls power distribution to a coil in accordance with a detection signal from the magnetic sensor (see, for example, Patent Literature 1).

PATENT LITERATURE

The pump described in Patent Literature 1 described above has a problem however in that the direct material cost increases due to an increase in the magnet volume of the position-detection magnet unit.

SUMMARY

The present invention has been achieved in view of the above problems, and an objective of the present invention is to provide a pump that can reduce the magnetic amount to be used for a rotor-position detecting magnetic-pole portion that is provided in a magnet of a rotor and that can maintain detection accuracy of a magnetic pole position, while enabling the realization of cost reduction, a method of manufacturing the pump, and a refrigeration cycle device provide with the pump.

To solve the problem and achieve the objective described above, provided is a pump that includes: an annular molded stator having a substrate mounted with a magnetic-pole position detection element; and a rotor having an annular rotor unit rotatably housed in a cup-shaped partition component, with one end thereof in an axial direction facing the magnetic-pole position detection element and with the other end thereof in the axial direction being provided with an impeller attachment unit to which an impeller is attached. The rotor unit includes an annular magnet, a sleeve bearing provided inside of the magnet, and a resin portion used for integrally molding the magnet and the sleeve bearing and for forming the impeller attachment unit, the magnet includes a rotor-position detecting magnetic-pole portion, which protrudes axially with a predetermined height in an annular shape having a predetermined width in a radial direction, on an outer periphery of an end face opposite to the magnetic-pole position detection element, and the rotor-position detecting magnetic-pole portion is provided with a plurality of arc-shaped notches on the circumference on an inner diameter side thereof.

According to the present invention, it is possible to reduce the magnet amount to be used for a rotor-position detecting magnetic-pole portion provided in the magnet of a rotor and to maintain detection accuracy of the magnetic pole position, while enabling cost reduction to be realized.

DETAILED DESCRIPTION

Exemplary embodiments of a pump, a method for manufacturing a pump, and a refrigeration cycle device according to the present invention will be explained below in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments.

First Embodiment

In the following descriptions, an outline of a heat-pump type water heater as an example of application of the pump according to the present embodiment is described first, and details of the pump are given next.

FIG. 1is a configuration diagram of a heat-pump type water heater according to the present embodiment. As illustrated inFIG. 1, a heat-pump type water heater300includes a heat pump unit100, a tank unit200, and an operating unit11that is used when a user performs a drive operation and the like.

InFIG. 1, the heat pump unit100includes a compressor1(for example, a rotary compressor or a scroll compressor) that compresses a refrigerant; a refrigerant-water heat exchanger2in which heat is exchanged between the refrigerant and water; a decompression device3that decompresses and expands the high-pressure refrigerant; an evaporator4that evaporates a low-pressure two-phase refrigerant; a refrigerant pipe15that connects the compressor1, the refrigerant-water heat exchanger2, the decompression device3, and the evaporator4in a circular circuit; a pressure detection device5that detects discharge pressure of the compressor1; a fan7that blows air into the evaporator4; and a fan motor6that drives the fan7. The compressor1, the refrigerant-water heat exchanger2, the decompression device3, the evaporator4, and the refrigerant pipe15that connects these in a circular circuit constitute a refrigerant circuit.

The heat pump unit100includes a boiling-point temperature detection unit8of the refrigerant-water heat exchanger2; a feed-water temperature detection unit9of the refrigerant-water heat exchanger2; and an ambient-air temperature detection unit17, as a temperature detection unit.

The heat pump unit100also includes a heat-pump-unit control unit13. The heat-pump-unit control unit13receives signals from the pressure detection device5, the boiling-up temperature detection unit8, the feed-water temperature detection unit9, and the ambient-air temperature detection unit17and executes control of the number of revolutions of the compressor1, control of the opening degree of the decompression device3, and control of the number of revolutions of the fan motor6.

The tank unit200includes a hot water tank14that stores hot water heated by exchanging heat with the high-temperature and high-pressure refrigerant in the refrigerant-water heat exchanger2; a bathwater-reheating heat exchanger31that reheats bathwater; a bathwater circulating device32connected to the bathwater-reheating heat exchanger31; a pump10being a hot-water circulating device arranged between the refrigerant-water heat exchanger2and the hot water tank14; a hot-water circulating pipe16that connects the refrigerant-water heat exchanger2and the hot water tank14; a mixing valve33connected to the refrigerant-water heat exchanger2, the hot water tank14, and the bathwater-reheating heat exchanger31; and a bathwater reheating pipe37that connects the hot water tank14and the mixing valve33. The refrigerant-water heat exchanger2, the hot water tank14, the pump10, and the hot-water circulating pipe16constitute a water circuit.

The tank unit200also includes an in-tank water-temperature detection unit34; a reheated water-temperature detection unit35that detects the water temperature after it has passed through the bathwater-reheating heat exchanger31; and a mixed water-temperature detection unit36that detects the water temperature after it has passed through the mixing valve33, as a temperature detection unit.

The tank unit200further includes a tank-unit control unit12. The tank-unit control unit12receives signals from the in-tank water-temperature detection unit34, the reheated water-temperature detection unit35, and the mixed water-temperature detection unit36, in order to execute control of the number of revolutions of the pump10and opening/closing control of the mixing valve33. The tank unit200further performs sending and receiving of signals to and from the heat-pump-unit control unit13and to and from the operating unit11.

The operating unit11is a remote controller or an operation panel including a switch for a user to set the temperature setting of the hot water or to instruct hot water to be supplied.

InFIG. 1, a normal boiling operation in the heat-pump type water heater300configured as described above is explained. When a boiling operation instruction from the operating unit11or the tank unit200is transmitted to the heat-pump-unit control unit13, the heat pump unit100performs a boiling operation.

The heat-pump-unit control unit13executes control of the number of revolutions of the compressor1, control of the opening degree of the decompression device3, and control of the number of revolutions of the fan motor6on the basis of the detection values of the pressure detection device5, the boiling-up temperature detection unit8, and the feed-water temperature detection unit9.

Further, the detection value detected by the boiling-up temperature detection unit8is transferred between the heat-pump-unit control unit13and the tank-unit control unit12; and the tank-unit control unit12controls the number of revolutions of the pump10so that the temperature detected by the boiling-up temperature detection unit8becomes a target boiling-up temperature.

In the heat-pump type water heater300controlled as described above, the high-temperature and high-pressure refrigerant discharged from the compressor1reduces its temperature, while dissipating heat to a water supply circuit. The high-temperature and high-pressure refrigerant, which has dissipated heat and passed through the refrigerant-water heat exchanger2, is decompressed by the decompression device3. The refrigerant having passed through the decompression device3flows into the evaporator4, and absorbs heat from ambient-air. The low-pressure refrigerant having been discharged from the evaporator4is drawn into the compressor1to repeat circulation, thereby forming a refrigeration cycle.

Meanwhile, water in a lower part in the hot water tank14is guided to the refrigerant-water heat exchanger2driven by the pump10which is the hot-water circulating device. Water is heated by heat dissipation from the refrigerant-water heat exchanger2; and the heated hot water passes through the hot-water circulating pipe16and is returned to an upper part of the hot water tank14and stored.

As explained above, in the heat-pump type water heater300, the pump10is used as the hot-water circulating device that circulates hot water through the hot-water circulating pipe16between the hot water tank14and the refrigerant-water heat exchanger2.

The pump10according to the present embodiment is explained next.FIG. 2is an exploded perspective view of the pump10according to the present embodiment.

As illustrated inFIG. 2, the pump10includes a pump unit40that absorbs and discharges water by the revolution of the rotor (described later); a molded stator50that drives the rotor; and tapping screws160that fasten the pump unit40to the molded stator50. In an example illustrated inFIG. 2, the number of tapping screws160is, for example, five. However, the number of tapping screws is not limited thereto.

The pump10is assembled by fastening five tapping screws160to pilot holes84of a pilot hole component81(for details, refer toFIG. 5illustrated later) embedded in the molded stator50via screw holes44aformed in a boss44of the pump unit40.

InFIG. 2, a casing41, an intake42, a discharge outlet43, a cup-shaped partition component90, a lead wire52, a mold resin53, a stator iron core54, and a pump-unit installation surface63are illustrated but they do not appear in the configurations explained above. These elements are explained later.

The configuration of the molded stator50is explained first with reference toFIGS. 3 to 5.FIG. 3is a perspective view of the molded stator50,FIG. 4is a cross-sectional view of the molded stator50, andFIG. 5is an exploded perspective view of a stator assembly49.

As illustrated inFIGS. 3 to 5, the molded stator50is acquired by mold-forming the stator assembly49by using the mold resin53.

On one end face of the molded stator50in an axial direction, specifically, on an end face on the side of the pump unit40(refer also toFIG. 2), a flat pump-unit installation surface63is provided along an outer peripheral edge thereof.

A leg part85(refer toFIGS. 4 and 5) of the pilot hole component81is axially embedded at five places in the pump-unit installation surface63. The leg part85is, for example, a substantially columnar resin molded component. At the time of mold forming by using the mold resin53, one end face of the leg part85(the end face on the side of the pump unit40) becomes a die pressing part82of a molding die (refer toFIG. 4). Therefore, the pilot hole component81is exposed in a form of being embedded inward from the pump-unit installation surface63by a predetermined distance. The exposed parts are the die pressing part82and the pilot hole84for the tapping screw160.

The lead wire52pulled out from the stator assembly49is pulled out to the outside from an external surface of the axial end face of the molded stator50opposite to the side of the pump unit40.

Axial positioning of the molded stator50by the mold resin53(for example, thermosetting resin) at the time of mold forming is performed by axial end faces of a plurality of protrusions95a, which are formed in a substrate pressing component95(refer toFIG. 5), functioning as a pressing part of an upper die. Therefore, the axial end faces (die pressing surfaces) of the protrusions95aare exposed (not illustrated) from the axial end face of the molded stator50on a side of a substrate58.

An axial end face of an insulation part56on an opposite side to a wire connection (on the side of the pump unit40) becomes a die pressing part of a lower die. Accordingly, from the axial end face of the molded stator50on the opposite side to the substrate58, the end face of the insulation part56on the opposite side to the wire connection is exposed (not illustrated).

Radial positioning of the molded stator50at the time of mold forming is made by fitting an inner periphery of the stator iron core to the die. Therefore, tip ends of teeth (the inner periphery) of the stator iron core54are exposed to the inner periphery of the molded stator50illustrated inFIG. 3.

The internal configuration of the molded stator50, that is, the configuration or the like of the stator assembly49is described next.

As illustrated inFIG. 5, the stator assembly49includes a stator47and a pilot hole component81. As illustrated inFIGS. 4 and 5, the stator47includes the lead wire52, the stator iron core54provided with grooves54a, the insulation part56, a coil57, an IC58a, a Hall element58b, the substrate58, a terminal59, a lead-wire leading component61, and a substrate pressing component95. The pilot hole component81includes leg parts85, protrusions83and85aprovided in the leg parts85, and a connection part87.

The stator assembly49is manufactured in the procedure described below.

(1) An electromagnetic steel plate having a thickness of, for example, 0.1 millimeter to 0.7 millimeter is punched in a belt-like form, and the annular stator iron core54laminated by swaging, welding, or bonding is made from the electromagnetic steel plate. The stator iron core54has a plurality of teeth. Tip ends of the teeth of the stator iron core54are exposed to the inner periphery of the molded stator50illustrated inFIG. 3. The stator iron core54illustrated here has, for example, 12 teeth connected with thin connection parts. Therefore, inFIG. 3, the tip ends of the teeth of the stator iron core54are exposed at12positions. However, only five teeth of the 12 teeth are viewed inFIG. 3.
(2) The insulation part56is applied to the teeth of the stator iron core54. The insulation part56is formed integrally with or separately to the stator iron core54by using, for example, a thermoplastic resin such as PBT (polybutylene terephthalate).
(3) A concentratedly wound coil57(refer toFIG. 4) is wound around the teeth applied with the insulation part56. By connecting12concentratedly wound coils57, three-phase single Y-connection windings are formed.
(4) Because of the three-phase single Y-connection, terminals59(refer toFIG. 4, supply terminals to which power is supplied, and a neutral terminal) to which the coils57(refer toFIG. 4) of respective phases (a U phase, a V phase, and a W phase) are connected are assembled on the connection side of the insulation part56. There are three supply terminals and one neutral terminal.
(5) The substrate58is attached to the insulation part56on the connection side (on the side where the terminals59are assembled). The substrate58is held between the substrate pressing component95and the insulation part56. An electronic component is mounted on the substrate58, for example, the IC58a(drive element) that drives a motor (for example, a brushless DC motor), the Hall element58bthat detects the position of the rotor60(refer toFIG. 4, a magnetic-pole position detection element), and the like are provided thereon. Because the IC58ais mounted on the side of the substrate pressing component95of the substrate58, it is illustrated inFIG. 5. However, the Hall element58bis hidden and not seen inFIG. 5, because it is mounted on the opposite side to the IC58a. Further, the substrate58is attached with the lead-wire leading component61that leads out the lead wire52in a notched portion near the outer periphery thereof.
(6) The substrate58attached with the lead-wire leading component61is fixed to the insulation part56by the substrate pressing component95; and the pilot hole component81is assembled on the stator47to which the terminals59and the substrate58are soldered, thereby completing the stator assembly49(refer toFIG. 5).

The configuration of the pilot hole component81is explained next with reference toFIG. 5. The pilot hole component81is formed by molding a thermoplastic resin such as PBT (polybutylene terephthalate).

As illustrated inFIG. 5, the pilot hole component81is configured by circularly connecting a plurality (for example, five) of leg parts85in a substantially columnar shape with the thin connection part87. The leg part85is provided with the pilot hole84to be screwed into with the tapping screw160(refer toFIG. 2). The leg part85has a tapered shape, in which the leg part85becomes thicker from the exposed end face (the die pressing part82and the end face of the protrusion83) toward the axial center. By having such a tapered shape, the pilot hole component81is effectively prevented from falling off after performing mold forming with the stator47.

The pilot hole component81includes the plurality of protrusions85aon the outer periphery of the leg part85for preventing rotation. In the example illustrated inFIG. 5, four protrusions85aare provided on the outer periphery of the leg part85. The protrusion85ais formed to extend in a height direction (an axial direction) of the leg part85with a predetermined circumferential width. Further, the protrusion85aprotrudes from an outer peripheral surface of the leg part85by a required predetermined dimension in order to prevent the pilot hole component81from being rotated. The pilot hole component81can be set to the molding die in the first attempt by connecting the substantially columnar leg parts85with the thin connection part87, thereby enabling the machining cost to be reduced.

By providing a plurality of claws (not illustrated) for assembling the pilot hole component81on the stator47in the connection part87of the pilot hole component81and latching the claws of the pilot hole component81into the grooves54aformed on the outer periphery of the stator iron core54of the stator47, the stator47and the pilot hole component81can be set to the molding die in the first attempt, thereby enabling the machining cost to be reduced.

When the stator assembly49is mold-formed by the mold resin53after latching the pilot hole component81to the stator47, the axial positioning of the pilot hole component81is performed by holding the die pressing part82and the protrusions83of the pilot hole component81by the mold forming die.

An outer diameter of the die pressing part82can be set smaller than an outer diameter of an opening-side end face of the pilot hole component81(refer toFIG. 4). Thus, the end face of the pilot hole component81of a portion excluding the die pressing part82is covered with the mold resin53. Therefore, because the opposite end face of the pilot hole component81is covered with the mold resin53, exposure of the pilot hole component81is suppressed, thereby enabling the quality of the pump10to be improved.

The molded stator50is obtained by integrally molding the pilot hole component81assembled on the stator47by the mold resin53. In this case, the pilot holes84are molded so as to be exposed. By and assembling and fastening the pump unit40and the molded stator50to the pilot hole84with the tapping screws160via the screw holes44aformed in the pump unit40, the pump unit40and the molded stator50can be firmly assembled together (refer toFIG. 2).

The configuration of the pump unit40is to be explained next with reference toFIGS. 6 to 8.FIG. 6is an exploded perspective view of the pump unit40,FIG. 7is a cross-sectional view of the pump10, andFIG. 8is a perspective view of the casing41viewed from a side of a shaft support portion46. The pump unit40includes the following elements: (1) Casing41that has the intake42and the discharge outlet43of fluid and houses an impeller60bof the rotor60therein: The casing41is molded by using a thermoplastic resin, for example, PPS (polyphenylene sulfide). A boss44with a screw hole44a, which is used at the time of assembling the pump unit40and the molded stator50, is provided at five positions.

(2) Thrust bearing71: The material of the thrust bearing71is a ceramic, for example, alumina. The rotor60is pressed against the casing41via the thrust bearing71, due to a pressure difference acting on the both sides of the impeller60bof the rotor60during the operation of the pump10. Therefore, a thrust bearing made of a ceramic is used as the thrust bearing71to ensure wear resistance and sliding properties.
(3) Rotor60: The rotor60includes a rotor unit60aand the impeller60b. In the rotor unit60a, a ring-shaped (cylindrical or annular) resin magnet68(an example of a magnet) molded by using a pellet formed by kneading a magnetic powder, for example, ferrite powder and resin and a cylindrical sleeve bearing66(for example, made of carbon) provided inside of the resin magnet68are integrated at a resin portion67made of such as PPE (polyphenylene ether) (refer toFIG. 9explained later). The impeller60bis a resin molded product of, for example, PPE (polyphenylene ether). The rotor unit60aand the impeller60bare bonded by, for example, ultrasonic welding.
(4) Shaft70: The material of the shaft70(a rotary shaft) is a ceramic, for example, alumina, or SUS. Because the shaft70slides with the sleeve bearing66provided in the rotor60, a material such as a ceramic or SUS is selected so as to ensure the wear resistance and sliding properties. One end of the shaft70is inserted into a shaft support portion94of the cup-shaped partition component90; and the other end of the shaft70is inserted into the shaft support portion46of the casing41. Therefore, the one end of the shaft70to be inserted into the shaft support portion94is inserted therein so as not to rotate with respect to the shaft support portion94. Therefore, the one end of the shaft70is substantially D shaped, which is obtained by cutting a part of a circular form by a predetermined length (in an axial direction). A hole in the shaft support portion94has a shape matched with the shape of the one end of the shaft70. Further, the other end of the shaft70to be inserted into the shaft support portion46is also substantially D shaped, which is obtained by cutting a part of a circular form by a predetermined length (in an axial direction), and thus the shaft70has a symmetrical shape in a lengthwise direction. However, the other end of the shaft70is inserted rotatably into the shaft support portion46. The reason why the shaft is symmetrical in the lengthwise direction is because, at the time of inserting the shaft70into the shaft support portion94, it is possible to assemble it without taking into consideration whether the direction is up or down (refer toFIG. 6).
(5) O-ring80: The material of the O-ring80is, for example, EPDM (ethylene-propylene-diene rubber). The O-ring80seals the casing41from the cup-shaped partition component90of the pump unit40. In a pump mounted on a hot water dispenser, heat resistance and long life are required for sealing the piping. Therefore, the material such as EPDM is used to ensure the resistance properties.
(6) Cup-shaped partition component90: The cup-shaped partition component90is molded by using a thermoplastic resin, for example, PPE (polyphenylene ether). The cup-shaped partition component90includes a cup-shaped partition wall portion90athat is a joint with the molded stator50, and a flange portion90b. The cup-shaped partition wall portion90ais formed of a circular bottom and a cylindrical partition wall. The shaft support portion94, into which the one end of the shaft70is inserted, is provided in a standing condition substantially at the center on an internal surface of the bottom of the cup-shaped partition wall portion90a. On an external surface of the bottom of the cup-shaped partition wall portion90a, a plurality of ribs92are radially formed in a radial direction. A plurality of reinforcing ribs (not illustrated) are radially formed on the flange portion90bin the radial direction. The flange portion90balso includes an annular rib (not illustrated) housed in the pump-unit installation surface63of the pump unit40. The flange portion90bis formed with a hole90d, through which the tapping screw160passes, at five positions. A circular O-ring housing groove90cfor housing the O-ring80is formed on a surface of the flange portion90bon the side of the casing41.

The pump10is constructed by assembling the casing41to the cup-shaped partition component90after installing the O-ring80in the cup-shaped partition component90and installing the shaft70, the rotor60, and the thrust bearing71in the cup-shaped partition component90to construct the pump unit40; and further fixing the pump unit40to the molded stator50by the assembly tapping screws160and the like.

By fitting the ribs92provided on the bottom of the cup-shaped partition component90to the groove (not illustrated) in the molded stator50, circumferential positioning of the pump unit40and the molded stator50is performed.

The rotor60is housed inside of the cup-shaped partition wall portion90a. The rotor60is fitted to the shaft70inserted into the shaft support portion94of the cup-shaped partition component90. Therefore, to ensure concentricity between the molded stator50and the rotor60, it is better to keep the gap between an inner circumference of the molded stator50and an outer circumference of the cup-shaped partition wall portion90aas small as possible. For example, the gap is set to be about 0.02 millimeter to 0.06 millimeter.

However, if the gap between the inner circumference of the molded stator50and the outer circumference of the cup-shaped partition wall portion90ais too small, the escape route for air becomes narrow when the cup-shaped partition wall portion90ais inserted into the inner circumference of the molded stator50, thereby making it difficult to insert the cup-shaped partition component90.

FIG. 9is a cross-sectional view of the rotor unit60a(specifically, a cross-sectional view along arrow A-A inFIG. 11);FIG. 10is a side view of the rotor unit60aviewed from a side of an impeller attachment unit67a;FIG. 11is a side view of the rotor unit60aviewed from an opposite side to the side of the impeller attachment unit67a; andFIG. 12is an enlarged cross-sectional view of the sleeve bearing66.

The rotor unit60ais explained with reference toFIGS. 9 to 12. As illustrated inFIGS. 9 to 12, the rotor unit60aincludes at least the following elements:

(3) Resin portion67. The resin portion67is constituted by a thermoplastic resin, for example, PPE (polyphenylene ether). The impeller attachment unit67a, to which the impeller60bis attached, is formed in the resin portion67. The resin magnet68and the sleeve bearing66are integrally molded by using the resin portion67.

The resin magnet68is substantially ring shaped (cylindrical or annular shape), and is molded by using the pellet formed by kneading it with a magnetic powder, for example, ferrite powder and resin.

The sleeve bearing66(for example, made of carbon) is provided inside of the resin magnet68. The sleeve bearing66has a cylindrical shape. The sleeve bearing66is fitted to the shaft70which is assembled on the cup-shaped partition component90of the pump10to rotate. Therefore, the sleeve bearing66is fabricated by a material suitable for the bearing, for example, a thermoplastic resin such as PPS (polyphenylene sulfide) added with sintered carbon or carbon fiber, or a ceramic. The sleeve bearing66is provided with a drawing-out taper (not illustrated), which has an outer diameter decreasing with distance from a substantially axial center toward the opposite ends, and is provided with, for example, a plurality of semispherical protrusions66a(refer toFIG. 12) on an outer periphery, which prevent the rotation substantially at an axial center.

A depression67bis formed in a portion formed on an end face of the resin magnet68on the side of the impeller attachment unit67aof the resin portion67, corresponding to a magnet pressing part (not illustrated) provided on the upper die of the resin molding die. The depression67bis formed substantially at the center in a radial direction in the example illustrated inFIG. 9. The depression67bis formed at a position facing the protrusion68aof the resin magnet68in the axial direction.

As illustrated inFIG. 10, a plurality of impeller positioning holes67cfor attaching the impeller60bare made in the impeller attachment unit67a. For example, three impeller positioning holes67care formed substantially at a regular interval in the circumferential direction. The impeller positioning holes67cpenetrate the impeller attachment unit67a. The impeller positioning holes67care respectively formed on a radial extension line in the middle of two protrusions68a(refer toFIG. 10) out of the three protrusions of the resin magnet68.

Furthermore, as illustrated inFIG. 10, for example, three gates67e, which are to be used when the rotor unit60ais molded by using the thermoplastic resin (the resin portion67), are respectively formed substantially at a regular interval in the circumferential direction. The respective gates67eare formed on the radial extension line of the protrusions of the resin magnet68, and inside relative to the impeller positioning holes67c.

Notches67dto be fitted to a positioning protrusion (not illustrated) provided in the lower die of the resin molding die are formed in a portion of the resin portion67formed on an inner periphery of the resin magnet68opposite to the side of the impeller attachment unit67a(refer toFIGS. 9 and 11). The notch67dare formed at four positions substantially with an interval of 90 degrees in the example illustrated inFIG. 11. A plurality (eight in the example illustrated inFIG. 11) of protrusions68e, being a part of the resin magnet68, are exposed from the resin portion67(refer toFIG. 11).

FIG. 13is a cross-sectional view of the resin magnet68(specifically, a cross-sectional view on arrow B-B inFIG. 14);FIG. 14is a side view of the resin magnet68viewed from the side of the protrusion68a;FIG. 15is a side view of the resin magnet68viewed from an opposite side to the side of the protrusion68a;FIG. 16is a perspective view of the resin magnet68viewed from the side of the protrusion68a; andFIG. 17is a perspective view of the resin magnet68viewed from the opposite side to the side of the protrusion68a.FIG. 18is a perspective view of the rotor unit60aviewed from the side of the impeller attachment unit; andFIG. 19is a perspective view of the rotor unit60aviewed from an opposite side to the side of the impeller attachment unit.

The configuration of the resin magnet68is explained with respect toFIGS. 13 to 19. The resin magnet68illustrated here has, for example, eight magnetic poles. The resin magnet68includes a plurality of tapered notches68b, each arranged substantially at a regular interval in the circumferential direction on the inner periphery side of an end face opposite to the side of the impeller attachment unit67a. That is, the notches68bare formed on the inner periphery of the end face and are axially extended from the end face by a predetermined length. In the example illustrated inFIG. 15, there are eight notches68b. The notch68bhas a tapered shape with a diameter increasing on the end face side compared to the axial center side. The notches67dof the resin portion67(refer toFIG. 11) are formed at the same positions as the four notches68barranged substantially at an interval of 90 degrees.

The resin magnet68includes a plurality of protrusions68a, each being, for example, substantially horn shaped and extending axially by a predetermined length substantially at a regular interval in the circumferential direction on an inner periphery side at a predetermined depth from the end face opposite to the side where the notches68bare formed. In the example illustrated inFIG. 14, there are three protrusions68a.

As illustrated inFIG. 14, each protrusion68ahas a convex portion68a-1that is substantially horn shapes when viewed from the side and protrudes toward the end face. When the rotor unit60ais molded integrally, the convex portion68a-1provided at the end of the protrusion68ais held by the thermoplastic resin (the resin portion67) that forms the rotor unit60a. Accordingly, even if a slight gap is formed between the resin portion67and the resin magnet68due to resin shrinkage, the rotation torque of the resin magnet68can be reliably transmitted, thereby enabling the quality of the rotor unit60ato be improved. The shape of the protrusion68ais not limited to being substantially horn shaped, and can be any shape such as a triangle, trapezoid, semicircle, circular arc, or polygon.

The resin magnet68includes a plurality of gates68c, to each of which a plastic magnet (a material of the resin magnet68) is supplied, on the end face opposite to a magnetic-pole position detection element (the Hall element58b(refer toFIG. 4)) in a state of being molded in the rotor60(refer toFIG. 15). The position of the gate68cis, for example, between magnetic poles (refer toFIG. 15). With the gate68cbeing provided between the magnetic poles, variations in the magnetic poles can be suppressed, and detection accuracy of the magnetic pole position of the resin magnet68can be improved.

As illustrated inFIG. 13, a hollow portion of the resin magnet68has a straight shape from the end face where the protrusions68aare formed to the substantially axial center position and has a drawing-out taper shape from the end face opposite to the end face where the protrusions68aare formed to the substantially axial center position. Accordingly, the molded article can be easily taken out from the die, thereby enabling the productivity of the resin magnet68to be improved and the production cost to be reduced. That is, because the hollow portion of the resin magnet68has a drawn-out taper shape, it can be prevented that a part of or whole of the molded article is stuck to the die and is hard to taken out (attachment to the die), thereby enabling the productivity of the resin magnet68to be improved. The die for molding the resin magnet68is divided into a fixed die and a movable die on the end face on the drawn-out taper side of the protrusion68a. Because a part of the hollow portion formed by the movable die has a straight shape, sticking to the fixed die can be prevented further, and the productivity of the resin magnet68can be improved. The resin magnet68is pushed out from the movable die by an ejector pin.

As illustrated inFIG. 15, a plurality (eight in the example illustrated inFIG. 15) of protrusions68e, having a substantially elongated hole shape in cross section, are radially formed on the end face opposite to the magnetic-pole position detection element (the Hall element58b) of the resin magnet68. Further, as illustrated inFIG. 14, a plurality (eight in the example illustrated inFIG. 14) of depressions68d, each having a substantially elongated hole shape in cross section, is radially formed on the end face on the side of the impeller attachment unit67aof the resin magnet68.

When the rotor unit60ais integrally molded from the thermoplastic resin (the resin portion67), the protrusions68eand the depressions68dare embedded in the thermoplastic resin (the resin portion67), and the resin magnet68is held by the resin portion67.

As illustrated inFIG. 15, the protrusions68e, which are formed on the side opposite to the magnetic-pole position detection element (the Hall element58b), are formed, for example, substantially at the center of the magnetic pole formed in the rotor60. That is, the protrusions68eare formed on the circumference between the gates68cto which the material of the resin magnet68is supplied.

In this manner, with the protrusions68ebeing provided at the magnetic pole center, the magnetic force is improved and the performance of the pump10can be improved.

Furthermore, the depressions68dformed on the side of the impeller attachment unit67aof the resin magnet68are formed, for example, between the magnetic poles formed in the rotor60, that is, at the same positions where the gates68cto which the material of the resin magnet68is supplied are formed. In this manner, by providing the depressions68dbetween the magnetic poles, a decrease of the magnetic force is suppressed as much as possible, and thus a performance decrease of the pump10can be suppressed.

The number of at least one of the protrusions68eand the depressions68dcan be the same as the number of magnetic poles formed in the rotor60. By setting at least one of the protrusions68eand the depressions68dto be the same number as the number of magnetic poles, the unbalance of the magnetic force can be reduced.

The resin magnet68is provided with a rotor-position detecting magnetic-pole portion68f, which protrudes axially with a predetermined height in an annular shape having a predetermined width in a radial direction (refer toFIGS. 13 and 15), on an outer periphery of the end face opposite to the magnetic-pole position detection element (the Hall element58b). In this manner, by causing a part of the resin magnet68to protrude toward the magnetic-pole position detection element (the Hall element58b) as the rotor-position detecting magnetic-pole portion68fso as to reduce the axial distance between the rotor-position detecting magnetic-pole portion68fof the resin magnet68and the Hall element58bmounted on the substrate58, the detection accuracy of the magnetic pole position can be improved.

The rotor-position detecting magnetic-pole portion68fincludes, for example, an arc-shaped notch68grespectively at the center of each pole on the inner diameter side thereof (refer toFIG. 15). That is, a plurality (eight in the example illustrated inFIG. 15) of arc-shaped notches68gare provided on the inner diameter side of the rotor-position detecting magnetic-pole portion68f, and each arc-shaped notch68gis provided at a position at the magnetic pole center. These arc-shaped notches68gare formed by notching the inner diameter of the rotor-position detecting magnetic-pole portion68fin the same shape, and are arranged on the same circumference. In this manner, by providing the plurality of arc-shaped notches68gon the inner diameter side of the rotor-position detecting magnetic-pole portion68fto reduce the magnet amount at the magnetic pole center, the pump10can be manufactured at a low cost, while maintaining the detection accuracy of the magnetic pole position (refer toFIG. 15).

Although not illustrated, the rotor-position detecting magnetic-pole portion68fcan have a substantially sine wave shape on the inner diameter side such that the radial width thereof is the smallest at the magnetic pole center. That is, the inner diameter side of the rotor-position detecting magnetic-pole portion68fcan be notched as substantially sine wave shapes so that the radial width thereof is the smallest at the magnetic pole center. Also in this case, as in the example illustrated inFIG. 15, by reducing the magnet amount at the magnetic pole center, the pump10can be manufactured at a low cost, while maintaining the detection accuracy of the magnetic pole position.

As illustrated inFIG. 20, arc-shaped notches68hcan be respectively provided between magnetic poles on the inner diameter side of the rotor-position detecting magnetic-pole portion68f, as a modification of the resin magnet68. That is, a plurality (eight in the example illustrated inFIG. 20) of arc-shaped notches68his provided on the inner diameter side of the rotor-position detecting magnetic-pole portion68f, and each arc-shaped notch68his provided at a position between the magnetic poles. These arc-shaped notches68hare formed by notching the inner diameter of the rotor-position detecting magnetic-pole portion68fin the same shape and are arranged on the same circumference. With the resin magnet68according to the modification, the pump10can be manufactured at a low cost, while maintaining the pump performance. Further, in the configuration, by enlarging the diameter of the gate68cprovided between the magnetic poles of the resin magnet68, the moldability of the resin magnet68can be improved.

Although not illustrated, the rotor-position detecting magnetic-pole portion68fcan have a substantially sine wave shape on the inner diameter side such that the radial width thereof becomes the smallest between the magnetic poles. Also in this case, by reducing the magnet amount between the magnetic poles, the pump10can be manufactured at a low cost, while maintaining the detection accuracy of the magnetic pole position. Further, in the configuration, by enlarging the diameter of the gate68cprovided between the magnetic poles of the resin magnet68, the moldability of the resin magnet68can be improved.

In the present embodiment, the Hall element58bbeing a magnetic sensor is used as the magnetic-pole position detection element, and the Hall element58bis packaged together with an IC that converts an output signal thereof to a digital signal and is configured as a Hall IC, and the Hall IC is surface-mounted on the substrate58. By using the Hall IC surface-mounted on the substrate58to detect leakage flux of the resin magnet68from the axial end face (the surface opposite to the magnetic-pole position detection element) of the resin magnet68, the machining cost and the like of the substrate58can reduce the production cost of the pump10, as compared to a case where the Hall element58bis fixed to the substrate58by a Hall element holder (not illustrated) so as to detect the main magnetic flux of the resin magnet68from the side surface of the resin magnet68. In contrast, in the conventional arts, in order to detect the magnetic pole position, it has been necessary to assemble the magnetic-pole position detection element on the substrate by using a magnetic-pole position detection-element holder so that the magnetic-pole position detection element (the magnetic sensor) is positioned on an outer periphery of a position detection magnet. Therefore, there have been problems in ensuring an installation space of the magnetic-pole position detection element so as to increase the machining cost due to an increase in the number of components such as the magnetic-pole position detection-element holder.

Although not illustrated, as another modification of the resin magnet68, the position of the gate68c, to which the material of the resin magnet68is supplied, can be arranged at the magnetic pole center. In this case, the gate68ccan be provided in the protrusion68e. The resin magnet68according to this modification can improve orientation accuracy of the resin magnet68by positioning the gate68cat the magnetic pole center, thereby enabling the quality of the pump10to be improved.

Integral molding of the rotor60of the pump motor by the thermoplastic resin is described next. The resin magnet68is an example of the magnet.

The die for integrally molding the resin magnet68and the sleeve bearing66includes an upper die and a lower die (not illustrated). The sleeve bearing66is first set in the lower die. The sleeve bearing66can be set to the die without matching the circumferential direction, because the cross-sectional shape is symmetrical. The sleeve bearing66includes a plurality of protrusions66a(refer toFIG. 12) on the outer periphery thereof, but the position of the protrusions66ais not specifically limited. Therefore, an operation process is simplified so as to improve the productivity, and the production cost can be reduced.

When the sleeve bearing66is set in the lower die, the inner diameter of the sleeve bearing66is held in a sleeve-bearing insertion portion (not illustrated) provided in the lower die, thereby ensuring the accuracy of concentricity of the sleeve bearing66and the resin magnet68to be set in a subsequent process.

After the sleeve bearing66is set in the lower die, the resin magnet68is set in the lower die by fitting the tapered notches68bprovided on the inner peripheral edge of one of the end faces (the end face opposite to the impeller attachment unit67ain the state of the rotor60) to the positioning protrusions (not illustrated) provided in the lower die. In the example illustrated inFIG. 15, there are eight notches68b. Four notches among these, provided substantially at an interval of 90 degrees, are fitted to the positioning protrusions (not illustrated) in the lower die, thereby ensuring the accuracy of concentricity of the sleeve bearing66and the resin magnet68. The reason why the eight notches68bare provided is to improve the workability at the time of setting the resin magnet68in the lower die.

Further, the magnet pressing parts (not illustrated) provided in the upper die are axially pressed against the substantially horn-shaped protrusions68aformed on an inner peripheral edge of the other end face (the end face on the side of the impeller attachment unit67a, and in the state of the rotor60) of the resin magnet68. Accordingly, the positioning relation between the sleeve bearing66and the resin magnet68is secured.

In the example illustrated inFIG. 14, three substantially horn-shaped protrusions68aare provided on the inner periphery of the resin magnet68; and a die installation surface (a portion pressed by the die) of the protrusion68ais exposed after integrally being molded. The reason why there are three protrusions68ais to secure the positioning accuracy of the resin magnet68and ensure a flow passage of the thermoplastic resin to be used for integral molding, thereby alleviating the molding condition at the time of integral molding to improve the productivity.

Even when there is a gap between an insertion portion (not illustrated) of the resin magnet68in the lower die and the outer diameter of the resin magnet68, an inner-diameter pressing part (the positioning protrusion) provided in the lower die ensures the concentricity, and the position relation and the concentricity between the sleeve bearing66and the resin magnet68can be ensured by sandwiching these by the upper die and the lower die, thereby enabling the quality of the pump10to be improved.

In contrast, by making a gap between the insertion portion (not illustrated) of the resin magnet68in the lower die and the outer diameter of the resin magnet68, the workability at the time of setting the resin magnet68in the die is improved so as to reduce the production cost.

After the resin magnet68and the sleeve bearing66have been set in the die, the thermoplastic resin such as PPE (polyphenylene ether) is injected and molded, thereby forming the rotor unit60a. At this time, the notches68b(FIG. 15) of the resin magnet68that are not pressed by the die, that is, the four notches68b, the protrusions68eprovided on the end face opposite to the magnetic-pole position detection element of the resin magnet68, and the depressions68dprovided on the end face on the side of the impeller attachment unit67aare embedded in the resin portion67of the thermoplastic resin so as to form a transmitting portion of the rotation torque. Further, the protrusions68eand the depressions68dare embedded in the resin portion67of the thermoplastic resin, thereby firmly holding the resin magnet68.

After the resin magnet68and the sleeve bearing66have been integrally molded by using the thermoplastic resin (the resin portion67), at the time of magnetizing the resin magnet68, highly accurate magnetization can be performed by using the notches67d(four notches inFIG. 11) formed on the inner periphery of the one end face in the axial direction of the resin magnet68for positioning at the time of magnetization.

The manufacturing process of the pump10is described next with reference toFIG. 21.FIG. 21illustrates the manufacturing process of the pump10.

(1) Step 1: The annular stator iron core54is formed by punching an electromagnetic steel plate having a thickness of about 0.1 millimeter to 0.7 millimeter in a belt-like form and then being laminated by swaging, welding, or bonding. The sleeve bearing66is made as well. The resin magnet68is also molded.
(2) Step 2: To wind a winding wire on the stator iron core54. The insulation part56using the thermoplastic resin such as PBT (polybutylene terephthalate) is applied to the teeth of the annular stator iron core54connected with the thin connection part. The concentratedly wound coil57is wound around the teeth applied with the insulation part56. For example, if12(twelve) concentratedly wound coils57are connected, three-phase single Y-connection windings are formed. Because the winding is three-phase single Y-connection, the terminals59(the supply terminals to which power is supplied and the neutral terminal) of the stator47, to which the coils57of respective phases (a U phase, a V phase, and a W phase) are connected, are assembled on the connection side of the insulation part56. The substrate58is manufactured as well. The substrate58is held between the substrate pressing component95and the insulation part56. The IC that drives a motor (for example, a brushless DC motor), the Hall element58bthat detects the position of the rotor60, and the like are mounted on the substrate58. Further, the substrate58is fitted with the lead-wire leading component61that leads out the lead wire52at the notched portion near the outer periphery thereof. The rotor unit60ais manufactured as well. In the rotor unit60a, the ring-shaped (cylindrical or annular) resin magnet68molded by using the pellet formed by kneading a magnetic powder, for example, ferrite powder and resin and the cylindrical sleeve bearing66(for example, made of carbon) provided inside of the resin magnet68are integrally molded by using the resin such as PPE (polyphenylene ether). The structure of the resin magnet68is as described above with reference toFIGS. 9 to 20. The impeller60bis also molded. The impeller60bis molded by using the thermoplastic resin such as PPE (polyphenylene ether).
(3) Step 3: The substrate58is to be assembled on the stator47. The substrate58fitted with the lead-wire leading component61is fixed to the insulation part56by the substrate pressing component95. The impeller60bis also assembled on the rotor unit60aby ultrasonic welding or the like. The cup-shaped partition component90is also molded. The shaft70and the thrust bearing71are manufactured. The shaft70is manufactured from, for example, SUS. The thrust bearing71is manufactured from, for example, ceramics.
(4) Step 4: The substrate58is soldered. The terminals59(the supply terminals to which power is supplied and the neutral terminal) are soldered to the substrate58. The pilot hole component81is molded. The casing41is also molded. The casing41is molded by using a thermoplastic resin such as PPS (polyphenylene sulfide). The rotor60and the like are assembled into the cup-shaped partition component90.
(5) Step 5: After having manufactured the stator assembly49by assembling the pilot hole component81in the stator47, the stator assembly49is mold-formed so as to manufacture the molded stator50. The casing41is fixed to the cup-shaped partition component90to assemble the pump unit40. The tapping screws160are also manufactured.
(6) Step 6: The pump10is assembled. The pump unit40is assembled on the molded stator50and fixed with the tapping screws160(refer toFIG. 2).

FIG. 22is a conceptual diagram illustrating a circuit of a refrigeration cycle device using the refrigerant-water heat exchanger2. The heat-pump type water heater300described above is an example of the refrigeration cycle device using the refrigerant-water heat exchanger2.

The refrigeration cycle device using the refrigerant-water heat exchanger2includes, for example, an air conditioner, a floor heating device, or a hot water dispenser. The pump10according to the present embodiment constitutes a water circuit of a device using the refrigerant-water heat exchanger2, and circulates water (hot water) cooled or heated by the refrigerant-water heat exchanger2in the water circuit.

The refrigeration cycle device illustrated inFIG. 22includes the refrigerant circuit having a compressor1(for example, a scroll compressor or a rotary compressor) that compresses the refrigerant, the refrigerant-water heat exchanger2that performs heat exchange between the refrigerant and water, the evaporator4(heat exchanger), and the like. The refrigeration cycle device also includes the water circuit having the pump10, the refrigerant-water heat exchanger2, a load20, and the like.

As described above, according to the present embodiment, the following effects can be achieved.

(1) The resin magnet68, integrally molded with the sleeve bearing66to constitute the rotor unit60a, includes the rotor-position detecting magnetic-pole portion68faxially protruding in an annular shape having a predetermined width and a predetermined height on the outer periphery of the end face opposite to the magnetic-pole position detection element (the Hall element58b(refer toFIG. 4)) (refer toFIGS. 13, 15, and 17). Due to such a configuration, the axial distance between the rotor-position detecting magnetic-pole portion68fand the Hall element58bmounted on the substrate58can be shortened, thereby enabling the detection accuracy of the magnetic pole position to be improved. Further, the rotor-position detecting magnetic-pole portion68fincludes the arc-shaped notches, for example, at the center of respective magnetic poles on the inner diameter side (refer toFIGS. 13, 15, and 17). Due to such a configuration, the magnet amount at the magnetic pole center can be reduced and the pump10can be manufactured at a low cost, while maintaining the detection accuracy of the magnetic pole position.
(2) The resin magnet68is provided with the arc-shaped notches, for example, between the respective magnetic poles on the inner diameter side of the rotor-position detecting magnetic-pole portion68f(refer toFIG. 20). With such a configuration, the magnet amount at the position between the magnetic poles can be reduced and the pump10can be manufactured at a low cost, while maintaining the pump performance. Further, by enlarging the diameter of the gate provided between the magnetic poles of the resin magnet68, the moldability of the resin magnet68can be improved.
(3) The resin magnet68is provided with the gates68c, to which the material of the resin magnet68is supplied, on the end face opposite to the magnetic-pole position detection element (the Hall element58b). Because the position of the gate68cis between the magnetic poles, the pump10can be manufactured at a low cost, while maintaining the detection accuracy of the magnetic pole position.
(4) The resin magnet68is provided with the gates68c, to which the material of the resin magnet68is supplied, on the end face opposite to the magnetic-pole position detection element (the Hall element58b); and because the position of the gate68cis at the center of the magnetic pole, the orientation accuracy of the resin magnet68can be improved.
(5) The plurality of protrusions68eare formed, each on the same circumference substantially at a regular interval in the circumferential direction and on the end face opposite to the magnetic-pole position detection element (the Hall element58b) of the resin magnet68, and these protrusions68eare arranged at the center of the magnetic poles. Accordingly, the magnetic force is improved, thereby enabling the performance of the pump10to be improved.
(6) The plurality of depressions68dare formed, each on the same circumference substantially at a regular interval in the circumferential direction and on the end face on the side of the impeller attachment unit67aof the resin magnet68, and these depressions68dare arranged at positions between the magnetic poles. Accordingly, a decrease of the magnetic force can be suppressed.
(7) The resin magnet68is provided with the plurality of notches68bin a substantially horn shape in cross section on the inner periphery side of the end face opposite to the magnetic-pole position detection element (the Hall element58b). With such a configuration, the die abuts on the notches68bwhen the rotor60is integrally molded. Accordingly, the workability is improved by performing positioning in the rotation direction of the resin magnet68, and the accuracy of concentricity of the resin magnet68and the sleeve bearing66is ensured.
(8) At least one of the protrusions68eformed on the opposite side to the magnetic-pole position detection element (the Hall element58b) and the depressions68dformed on the side of the impeller attachment unit67aof the resin magnet68are set such that they are the same in number as that of the magnetic poles formed in the rotor60, thereby enabling unbalance of the magnetic force of the resin magnet68to be suppressed.
(9) The hollow portion of the resin magnet68has a straight shape from the end face where the protrusions68aare formed to the substantially axial center position; and has a drawn-out taper shape from the end face opposite to the end face where the protrusions68aare formed to the substantially axial center position, thereby enabling the productivity of the resin magnet68to be improved.
(10) When the pump10is applied to the refrigeration cycle device using the refrigerant-water heat exchanger2(for example, an air conditioner, a floor heating device, or a hot water dispenser), the performance and quality of the refrigeration cycle device can be improved and cost can be reduced, due to the improvement of the performance, quality, and the productivity of the pump10.
(11) Other effects directed from the present embodiment are as described in the descriptions of the configurations.

INDUSTRIAL APPLICABILITY

As explained above, the present invention is useful as a pump, a method for manufacturing a pump, and a refrigeration cycle device.