JP7186342B2 - electric pump - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric pump, and more particularly to an electric pump used in a vehicle cooling system.

2. Description of the Related Art A vehicle such as an automobile uses a cooling system that cools heat-generating devices in the vehicle with coolant (cooling water) cooled by a radiator. For example, in a hybrid vehicle, a cooling system is used that cools a power unit including an inverter, a converter, and the like by sending refrigerant cooled by a radiator through piping. In such a cooling system, an electric pump is used to circulate the coolant inside the pipes.

This type of electric pump is an electric pump that sucks and discharges refrigerant, and includes a pump chamber having a suction port for sucking the refrigerant and a discharge port for discharging the sucked refrigerant, and an impeller disposed in the pump chamber. and a motor chamber for rotating the

The pump chamber is formed by two housings, and the two housings are fixed with a plurality of screws. The contact surfaces of the two housings are sealed to seal the pump chamber.

When the pressure of the refrigerant is applied to the pump chamber, the housing between the screws is deformed, and the refrigerant leaks from the seal surface.

In order to solve this problem, there is known an electric pump provided with an annular reinforcing rib that connects the screw seats of the housing (for example, Patent Document 1).

JP-A-5-172078

In conventional electric pumps, in order to suppress the deformation of the housing between the screws when the pump chamber is pressurized by the refrigerant, an annular reinforcing rib is provided near the outer periphery of the upper surface of the housing to connect the screw seats. there is

However, the annular reinforcing rib that connects the screw seats cannot completely suppress the deformation of the housing between the screws.

Compared to conventional electric pumps, the electric pump of the present disclosure improves the rigidity of the housing, reduces the deformation of the housing between screws, improves the sealing performance of the sealing surface, and suppresses refrigerant leakage from the sealing surface. intended to

To achieve the above object, one aspect of the electric pump according to the present invention is an electric pump, in which a housing of the electric pump includes a suction port for sucking refrigerant and a discharge port for discharging the sucked refrigerant. and an outlet, and a pump chamber having an impeller for sucking and discharging refrigerant by rotating inside the housing, wherein the housing includes a first housing portion provided with a suction port and a discharge port; and a second housing portion to which an impeller shaft to which is rotatably fixed is fixed, and the pump chamber is formed by a space surrounded by the first housing portion and the second housing portion. The first housing portion and the second housing portion are in contact with each other at the first sealing surface with the sealing material interposed therebetween. The second housing part has a first outer peripheral side located on the outer periphery. The first housing portion has a first annular rib formed on the outer periphery of the first sealing surface so as to cover the first outer peripheral side surface with a gap therebetween. The first annular rib covers the end portion of the sealing material in the direction of the first outer peripheral side surface in the gap.

According to the electric pump of the present disclosure, it is possible to improve the rigidity of the housing, reduce the deformation of the housing between the screws, improve the sealing performance of the sealing surface, and suppress refrigerant leakage from the sealing surface.

Sectional view of an electric pump according to an embodiment Appearance perspective view of an electric pump according to an embodiment 1 is an exploded perspective view of a housing of an electric pump according to an embodiment; Detailed cross-sectional view of the sealing surface of the electric pump according to the embodiment Cross-sectional view of a conventional electric pump (magnet coupling pump) Appearance perspective view of a conventional electric pump (magnet coupling pump) Detailed sectional view of a conventional electric pump (magnet coupling pump)

Embodiments of the present disclosure will be described below. It should be noted that each of the embodiments described below is a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, etc. shown in the following embodiments are examples and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest level concept of the present invention will be described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily strictly illustrated. Therefore, the scales and the like are not always the same in each drawing. In each figure, the same reference numerals are assigned to substantially the same configurations, and duplicate descriptions are omitted or simplified.

(Embodiment)
An electric pump according to an embodiment will be described below with reference to FIGS. 1 to 4. FIG. 1 to 3 are diagrams showing the configuration of an electric pump according to an embodiment. FIG. 1 is a cross-sectional view of the electric pump, FIG. 2 is an external perspective view of the electric pump, and FIG. 3 is a housing of the electric pump. It is an exploded perspective view. 5 to 7 are diagrams showing the configuration of a conventional electric pump (magnet coupling pump), FIG. 5 being a cross-sectional view, FIG. 6 being an external perspective view, and FIG. 7 being a detailed cross-sectional view.

The electric pump 1 is an electric pump that uses refrigerant as a working fluid and sucks and discharges the refrigerant by the power of a motor. Electric pump 1 in the present embodiment is an electric water pump that uses water (cooling water) as a coolant.

The electric pump 1 is a cooling pump incorporated in a circulation path connected to a heat exchanger such as a radiator. In a hybrid vehicle, for example, the electric pump 1 circulates cooling water cooled by a radiator to supply cooling water to a power unit including an inverter, a converter, or the like, an engine (internal combustion engine), or the like.

As shown in FIG. 1, the electric pump 1 includes a housing 100 having a pump chamber (pump casing) 100a and a motor chamber (motor casing) 100b, an impeller 200 arranged in the pump chamber 100a, and a A motor 300 and a drive circuit unit 400 are provided. The drive circuit unit 400 has a plurality of circuit components 410 and a circuit board 420 on which the plurality of circuit components 410 are mounted.

The housing 100 is an outer shell member forming the outer shell of the electric pump 1, and as shown in FIGS. It is The first housing portion 110, the second housing portion 120, and the third housing portion 130 are connected and fixed to each other by, for example, three screws 800 and nuts 900. As shown in FIG.

The first housing portion 110, the second housing portion 120, and the third housing portion 130 are made of a resin material, a metal material, or the like. In the present embodiment, first casing portion 110, second casing portion 120, and third casing portion 130 are made of PPS (Polyphenylene Sulfide) resin, which has relatively high thermal conductivity among resin materials. there is

The pump chamber 100 a is a region through which cooling water passes, and is configured by a first housing portion 110 and a second housing portion 120 . That is, the pump chamber 100a is a spatial region surrounded by the first housing portion 110 and the second housing portion 120, and the first housing portion 110 and the second housing portion 120 serve as partition walls to form a flow path. is doing.

The pump chamber 100a has a suction port 101 for sucking cooling water and a discharge port 102 for discharging the sucked cooling water. In this embodiment, the suction port 101 and the discharge port 102 are provided in the first housing portion 110 . The suction port 101 and the discharge port 102 have a long cylindrical shape, and are provided in the first housing part 110 so that the extending directions of the cylinders are twisted.

Specifically, the suction port 101 is provided so that the direction in which the cooling water flows in the suction port 101 and the rotational axis of the impeller 200 are substantially parallel. On the other hand, the discharge port 102 is provided such that the direction in which the cooling water flows in the discharge port 102 and one of the tangential directions of the rotation circle of the impeller 200 are substantially parallel. As a result, the cooling water is drawn into the pump chamber 100 a from the suction port 101 and discharged from the discharge port 102 by the rotation of the impeller 200 .

The motor chamber 100b is composed of a second housing portion 120 and a third housing portion 130. As shown in FIG. The motor chamber 100b is a spatial region surrounded by the second housing portion 120 and the third housing portion 130, and the second housing portion 120 and the third housing portion 130 serve as partition walls to form a closed space. forming. Thus, in the present embodiment, the second housing portion 120 also serves as a partition between the pump chamber 100a and the motor chamber 100b.

A motor 300 and a drive circuit unit 400 are housed in the motor chamber 100b. That is, the motor 300 and the drive circuit unit 400 are arranged in the same internal space (motor chamber 100b). Specifically, in the motor chamber 100b, the motor 300 is housed, and a plurality of circuit components 410 and circuit boards 420 are also housed.

The electric pump 1 according to the present embodiment has a structure in which the second housing portion 120 is a boundary and is separated into a pump chamber 100a that is a liquid layer and a motor chamber 100b that is an air layer. That is, in the electric pump 1, the motor 300 in the motor chamber 100b is not immersed in the cooling water, unlike the canned motor pump in which the rotor of the motor is immersed in the cooling water. That is, the electric pump 1 has a structure in which cooling water does not flow into the motor chamber 100b.

The impeller (vane wheel) 200 has a disk-shaped bottom (base) 210 and a plurality of blades (blades) 220 and is arranged at a position facing the suction port 101 . A plurality of blades 220 are fixed to the bottom portion 210 . In this embodiment, the plurality of blades 220 are open blades, and are arranged substantially radially around the central axis of impeller 200 .

A bearing 230 is provided coaxially with the central axis of the impeller 200 , and an annular driven magnet 240 and an annular back yoke 250 are provided coaxially with the central axis on the lower surface of the bottom portion 210 . Bearing 230 , driven magnet 240 and back yoke 250 are fixed to bottom 210 .

The impeller shaft 500 is fixed to the second housing portion 120 coaxially with the central axis of the second housing portion 120 and arranged in the pump chamber 100a.

Impeller 200 is rotatably fixed to impeller shaft 500 via bearing 230 .

The washer 600 is fixed to the tip of the impeller shaft 500 by the tip screw portion of the impeller shaft 500 and the nut 700, and suppresses the movement of the impeller 200 in the thrust direction.

The motor 300 is, for example, an inner rotor type DC brushless motor, and has a stator 310 (stator) and a rotor (rotor) 320 arranged on the inner peripheral side of the stator 310 .

The stator 310 has a plurality of coils 311 (windings), and when the coils 311 are energized, magnetic flux is generated on the inner peripheral side. In this embodiment, stator 310 is fixed to motor frame 330 . Note that the motor frame 330 is fixed to the third housing portion 130 .

The rotor 320 has a structure in which a rotor shaft 323 is connected to a rotor frame 321 . The magnetic pole portion 322 is a cylindrical member that is fixed to the outer periphery of the rotor frame 321 and is installed so as to face the inner peripheral surface of the stator 310 with a small gap (air gap) therebetween. A plurality of magnetic poles (for example, permanent magnets in which N poles and S poles are alternately arranged in the circumferential direction) are provided corresponding to the coils 311 . The rotor shaft 323 is supported by bearings provided on the motor frame 330 and bearings provided on the second housing portion 120 . A magnet holder 324 is fixed to the tip of the rotor shaft 323 , and an annular driving magnet 325 is fixed to the outer periphery of the magnet holder 324 coaxially with the rotor shaft 323 .

The driving magnet 325 and the driven magnet 240 are provided with a plurality of magnetic poles and have the same number of magnetic poles. The driving magnet 325 and the driven magnet 240 are attracted to each other by magnetic force at their opposing N and S poles. The drive magnet 325 and the driven magnet 240 are arranged coaxially.

When the driving magnet 325 fixed to the rotor shaft 323 via the magnet holder 324 rotates, the rotational force is transmitted to the driven magnet 240 by magnetic force, and the impeller 200 rotates. The driving magnet 325 is arranged in the motor chamber 100b, and the driven magnet 240 is arranged in the pump chamber 100a. The drive magnet 325 and the driven magnet 240 are separated by the partition wall of the second housing portion 120, and the rotational force of the drive magnet 325 is transmitted to the driven magnet 240 by the magnetic force passing through the partition wall of the second housing portion 120. . By rotating the impeller 200 arranged in the pump chamber 100 a , the cooling water is drawn into the pump chamber 100 a from the suction port 101 and discharged from the discharge port 102 .

The drive circuit unit 400 includes a plurality of circuit components 410 for driving the motor 300,
and a circuit board 420 on which a plurality of circuit components 410 are mounted.

A plurality of circuit components 410 constitute a drive circuit or the like for driving motor 300 . The circuit component 410 (circuit element) is, for example, a capacitive element such as an electrolytic capacitor or a ceramic capacitor, a resistive element such as a resistor, a coil element, or a semiconductor element such as a microcomputer (integrated circuit element). Circuit component 410 may also include a rotational position detection element (Hall IC) for detecting the rotational position of rotor 320 .

In the present embodiment, most of the plurality of circuit components 410 are mounted on the impeller 200 side surface of the circuit board 420 .

A through hole 421 through which the rotor shaft 323 passes is formed in the circuit board 420 . The through hole 421 is, for example, circular, but is not limited to this.

In the present embodiment, as shown in FIG. 1, the pump chamber 100a is a spatial region surrounded by the first housing portion 110 and the second housing portion 120. The contact surface of the housing portion 120 is sealed to seal the pump chamber 100a. Specifically, it is sealed by a circumferential pump chamber seal surface 100c , which is a first seal surface .

Further, the motor chamber 100b is a spatial region surrounded by the second housing portion 120 and the third housing portion 130, and the contact surface between the second housing portion 120 and the third housing portion 130 is the motor chamber. 100b is sealed to hermetic. Specifically, it is sealed by a circumferential motor chamber seal surface 100d , which is a second seal surface .

In the present embodiment, as shown in FIGS. 1 to 4, a portion of the first casing portion 110 is formed on the outer circumference of the pump chamber seal surface 100c of the first casing portion 110, and extends in the outer circumference annular direction. A continuous first annular rib 111 protrudes so as to cover the end portion of the pump chamber sealing surface 100c in the outer peripheral direction of the second housing portion 120 and the outer peripheral side surface of the second housing portion 120, and extends along the outer periphery. It is provided through a side surface and a gap. When the first housing portion 110 and the second housing portion 120 are assembled by contacting the pump chamber sealing surface 100c, the first annular rib 111 provided on the first housing portion 110 is aligned with the second housing portion 120. It overlaps with the outer peripheral side surface with a constant gap provided.

Further, a second annular rib 121 formed by a part of the second housing portion 120 on the outer periphery of the motor chamber sealing surface 100d of the second housing portion 120 and continuously extending in the direction of the outer circumference is used as the motor chamber seal. It protrudes so as to cover the end portion of the surface 100d in the outer peripheral direction of the third housing portion 130 and the outer peripheral side surface of the third housing portion 130, and is provided with a gap between the outer peripheral side surface and the outer peripheral side surface. When the second housing portion 120 and the third housing portion 130 are assembled by contacting the motor chamber sealing surface 100d, the second annular rib 121 provided on the second housing portion 120 is positioned on the third housing portion 130. It overlaps with the outer circumference with a certain gap provided.

As shown in FIGS. 5 and 6, the conventional magnet coupling pump does not have the first annular rib 111 and the second annular rib 121, and is fixed by the pump chamber seal surface 1100c and the motor chamber seal surface 1100d. .

In this embodiment, FIG. 1 shows the flow of cooling water. As the impeller 200 rotates clockwise (CW direction) when viewed from the suction port 101 , cooling water is drawn into the pump chamber 100 a from the suction port 101 and discharged from the discharge port 102 . As a result, pressure is generated by the cooling water in the pump chamber 100a.

In the present embodiment, as shown in FIGS. 1 to 4, a continuous first annular rib 111 protrudes from the pump chamber seal surface 100c on the outer circumference of the pump chamber seal surface 100c of the first housing portion 110. Since the first annular rib 111 receives pressure more integrally than the annular reinforcing rib that connects the screw seats in a conventional electric pump, there is no partial concentration of stress, and the pump chamber seal surface 100c The rigidity of the first housing portion 110 in the vicinity can be improved, and deformation of the pump chamber sealing surface 100c between the screws of the first housing portion 110 can be reduced. As a result, the sealing performance of the pump chamber seal surface 100c can be improved, and cooling water leakage from the pump chamber seal surface 100c can be suppressed.

In the conventional magnetic coupling pump, as shown in FIG. 7, when a liquid gasket is used to seal the pump chamber sealing surface 1100c, the pasty liquid gasket 1112 flowing out from the pump chamber sealing surface 1100c to the outer periphery is , adhered to the outside of the first housing portion 1110 and the second housing portion 1120, causing a poor appearance due to dirt, and required additional work to remove the adhering liquid gasket.

On the other hand, in the electric pump 1 of the present embodiment, as shown in FIG. 4, when the liquid gasket is used to seal the pump chamber seal surface 100c, the first annular Since the rib 111 overlaps the outer circumference of the second housing part 120 with a gap, the liquid gasket 112 that has flowed out to the outer circumference of the pump chamber sealing surface 100c is separated from the inner wall of the first annular rib 111 and the second outer circumference. It stays in the gap of the housing part 120 and becomes a rubber-like solid after a certain period of time.

As a result, the liquid gasket 112 does not adhere to the outside of the first housing portion 110 and the second housing portion 120, there is no appearance defect due to contamination, and there is no need to remove the adhered liquid gasket.

It should be noted that the first housing portion 110 and the second housing portion 120 can be brought into contact with each other via a sufficient amount of the liquid gasket 112, and as a result, the first housing portion 110 and the second housing portion 120 A liquid gasket 112 is provided between the joints of the two and the joints to the pump chamber seal surface 100c so as to suppress leakage of the refrigerant from the pump chamber seal surface 100c.

In the conventional magnetic coupling pump, as shown in FIG. 7, when the motor chamber sealing surface 1100d is sealed using a liquid gasket, the pasty liquid gasket 1122 flowing out from the motor chamber sealing surface 1100d to the outer periphery is , adhered to the outside of the second housing portion 1120 and the third housing portion 1130, causing a poor appearance due to contamination, and required additional work to remove the adhering liquid gasket.

On the other hand, in the electric pump 1 of the present embodiment, as shown in FIG. 4, when the motor chamber sealing surface 100d is sealed using a liquid gasket, the second annular rib provided on the second housing portion 120 121 overlaps the outer circumference of the third housing portion 130 with a gap, so that the liquid gasket 122 that has flowed out to the outer circumference of the motor chamber sealing surface 100 d flows into the inner wall of the second annular rib 121 and the third housing portion 130 . It stays in the gaps of the body 130 and becomes a rubber-like solid after a certain period of time.

As a result, the liquid gasket 122 does not adhere to the outside of the second housing portion 120 and the third housing portion 130, there is no appearance defect due to contamination, and there is no need to remove the adhered liquid gasket.

As described above, by providing the first annular rib 111 connected in the outer peripheral annular direction on the outer periphery of the pump chamber seal surface 100c of the first housing portion 110 so as to protrude from the pump chamber seal surface 100c, the first annular rib 111 integrally receives pressure, there is no partial concentration of stress, and the rigidity of the first housing portion 110 near the pump chamber sealing surface 100c is improved, and the pump chamber between the screws of the first housing portion 110 is improved. The deformation of the seal surface 100c is reduced, the sealing performance of the pump chamber seal surface 100c is improved, and cooling water leakage from the pump chamber seal surface 100c is suppressed.

In the present embodiment, a liquid gasket is used as a sealing material for the pump chamber sealing surface 100c, but rubber, resin, metal, or other non-liquid gaskets may be used. Alternatively, a groove may be provided in the second housing portion 120 or the first housing portion 110 and an O-ring may be used. By providing the first annular rib 111 against the compressive reaction force of the gasket and the O-ring, the rigidity of the first housing part 110 is improved and the deformation of the first housing part 110 between screws is reduced. As a result, the sealing performance of the pump chamber sealing surface 100c can be improved, and cooling water leakage from the pump chamber sealing surface 100c can be suppressed.

It should be noted that the function similar to that of the first annular rib 111 is that a third annular rib projecting in the direction of the suction port 101 from the pump chamber sealing surface 100c, which is the first sealing surface, of the second housing portion 120. Also, a function similar to that of the second annular rib 121 can be achieved by extending the third housing portion 130 from the motor chamber sealing surface 100d , which is the second sealing surface, toward the suction port 101. It can also be realized by a configuration in which a rib , which is a fourth annular rib, protrudes outward.

In addition, although the motor 300 is an inner rotor type DC brushless motor in the above embodiment, it is not limited to this.

Furthermore, the electric pump of the present disclosure uses a magnetic coupling to transmit the driving force of the rotor shaft 323 of the motor to the impeller. It can also be applied to an electric pump that transmits by mechanical parts.

In addition, forms obtained by applying various modifications that a person skilled in the art can think of to each of the above embodiments, or arbitrarily combining the constituent elements and functions of the above embodiments without departing from the spirit of the present invention Also included in the present invention is a form implemented by

An electric pump according to the present disclosure is a pump for circulating a coolant such as water (cooling water), and can be used, for example, as an electric water pump used in a vehicle cooling system or the like.

Reference Signs List 1 electric pump 100 housing 101 suction port 102 discharge port 100a pump chamber 100b motor chamber 100c pump chamber sealing surface 100d motor chamber sealing surface 110 first housing portion 111 first annular rib 112 liquid gasket 120 second housing portion 121 Second annular rib 122 Liquid gasket 130 Third housing 200 Impeller 210 Bottom 220 Blade 230 Bearing 240 Driven magnet 250 Back yoke 300 Motor 310 Stator 311 Coil 320 Rotor 321 Rotor frame 322 Magnetic pole 323 Rotor shaft 324 Magnet holder 325 Drive Magnet 330 Motor frame 400 Drive circuit unit 410 Circuit component 420 Circuit board 421 Through hole 500 Impeller shaft 600 Washer 700 Nut 800 Screw 900 Nut

Claims (6)

an electric pump,
In the housing of the electric pump,
A suction port for sucking refrigerant and a discharge port for discharging the sucked refrigerant,
Inside the housing,
A pump chamber having an impeller that sucks and discharges the refrigerant by rotating,
The housing is
a first housing portion provided with the suction port and the discharge port;
a second housing portion to which an impeller shaft to which the impeller is rotatably fixed is fixed;
The pump chamber is formed by a space surrounded by the first housing and the second housing,
the first housing portion and the second housing portion are in contact with each other at a first sealing surface with a sealing material interposed therebetween;
The second housing part has a first outer peripheral side located on the outer periphery,
The first housing portion has a first annular rib formed on the outer periphery of the first sealing surface so as to cover the first outer peripheral side surface with a gap therebetween, and
The electric pump, wherein the first annular rib covers an end portion of the seal member in the first outer peripheral side surface direction in the gap. Inside the housing,
further comprising a motor chamber in which a motor for rotating the impeller disposed in the pump chamber is disposed;
The housing is
further comprising a third housing portion in which the motor and the motor drive circuit are arranged;
the motor chamber is formed by a space surrounded by the second housing portion and the third housing portion;
the second housing portion and the third housing portion are in contact with each other at a second sealing surface with a sealing material interposed therebetween;
The third housing part has a second outer peripheral side located on the outer periphery,
The second housing portion has a second annular rib formed on the outer periphery of the second sealing surface so as to cover the second outer peripheral side surface with a gap therebetween, and
2. The electric pump according to claim 1 , wherein said second annular rib covers an end portion of said sealing member in said second outer peripheral side surface direction in said gap . an electric pump,
In the housing of the electric pump,
A suction port for sucking refrigerant and a discharge port for discharging the sucked refrigerant,
Inside the housing of the electric pump,
A pump chamber having an impeller that sucks and discharges the refrigerant by rotating,
The housing is
a first housing portion provided with the suction port and the discharge port;
a second housing portion to which an impeller shaft to which the impeller is rotatably fixed is fixed;
The pump chamber is formed by a space surrounded by the first housing and the second housing ,
the first housing portion and the second housing portion are in contact with each other at a first sealing surface with a sealing material interposed therebetween;
The first housing part has a third outer peripheral side located on the outer periphery,
The second housing portion has a third annular rib formed on the outer periphery of the first sealing surface so as to cover the third outer peripheral side surface with a gap therebetween, and
The electric pump, wherein the third annular rib covers an end portion of the seal member in the direction of the third outer peripheral side surface in the gap. Inside the housing,
further comprising a motor chamber in which a motor for rotating the impeller disposed in the pump chamber is disposed;
The housing is
further comprising a third housing portion in which the motor and the motor drive circuit are arranged;
the motor chamber is formed by a space surrounded by the second housing portion and the third housing portion ;
the second housing portion and the third housing portion are in contact with each other at a second sealing surface with a sealing material interposed therebetween;
The second housing part has a fourth outer peripheral side located on the outer periphery,
The third housing portion has a fourth annular rib formed on the outer periphery of the second sealing surface so as to cover the fourth outer peripheral side surface with a gap therebetween, and
4 . The electric pump according to claim 3 , wherein the fourth annular rib covers an end portion of the seal member in the direction of the fourth outer peripheral side surface in the gap. The electric pump according to any one of claims 1 to 4, wherein the sealing material is a liquid gasket. The first housing portion, the second housing portion, and the third housing portion are provided with screws arranged at least three places on the outer peripheral side of the housing with respect to the first to fourth annular ribs. 5. The electric pump according to claim 2 or 4, wherein said first and second sealing surfaces are fixed so as to press against each other.

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