JP2000213489A - Motor-driven fluid pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the rotation of a rotor from being inhibited by the metallic powder clogged between a partitioning wall and a permanent magnet in advance by forming a recess part recessed in the rotary shaft center direction, on a vertical surface of a permanent magnet with respect to the rotary shaft center of a rotor capable of fixing an impeller on its one end and fixing the permanent magnet on its outer peripheral surface. SOLUTION: When a motor-driven fluid pump 1 used for cooling a radiator, is operated, a rotor 5 is rotated, and an impeller 3 is rotated for making the fluid inflow from a discharge port and the fluid outflow to an intake port 2a. When the fluid flows from the discharge port to a communication hole, the metallic powder in the fluid sticks to a recess part 13A, and flows to the sliding bearing 6B side through a clearance between a partitioning wall 10 and a permanent magnet 4. The metallic powder not stuck to the recess part 13A is stuck to an outer peripheral surface of the permanent magnet 4, but the metallic powder stuck on the partitioning wall 10 side from an interval L2, is separated from an arbitrary part of the permanent magnet 4 by a defining member 15 to be discharged toward the recess part 13B side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pump, and more particularly, to an electric fluid pump driven to rotate by electric power.

[0002]

2. Description of the Related Art As a conventionally known fluid pump, a rotor which is supported by a housing via a slide bearing and has a permanent magnet disposed on an outer peripheral surface thereof, and a shaft of the rotor which is fixedly provided on an inner peripheral side of the housing. BACKGROUND ART There is known an electric fluid pump of a type including a stator having a core having a plurality of protrusions projecting toward the heart and a coil wound around the core, and being driven by controlling energization of the coil. I have. In such an electric fluid pump, it is preferable to set the interval between the permanent magnet and the core as small as possible in order to efficiently transfer magnetism. However, in the electric fluid pump of the type in which the rotor is supported via the above-described sliding bearing, since the fluid is poured from the impeller side to the permanent magnet side to lubricate the sliding bearing, for example, for cooling an automobile. When used, foreign matter such as metal powder contained in the fluid circulating in the engine block or the radiator may adhere to the outer peripheral surface of the permanent magnet. This is not preferable from the viewpoint of the performance of the electric fluid pump, since a failure such as damage to the pump can be considered.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electric fluid pump in which a rotor is supported by a bearing, wherein the influence of metal powder mixed into the fluid is as small as possible. Is a technical issue.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a housing having a fluid inlet and a fluid outlet, an impeller fixed to one end, and a permanent magnet fixed to the outer peripheral surface. A rotor that is disposed between the impeller and the permanent magnet, rotatably supports the rotor with respect to the housing, and communicates with the suction port and the discharge port in the housing to house the impeller, and A first bearing defined in a drive chamber accommodating a permanent magnet; a second bearing disposed at the other end of the rotor for rotatably supporting the rotor with respect to the housing; and fixed to a drive chamber wall of the housing. A stator having a plurality of protrusions projecting radially inward toward the rotor side and extending in the axial direction at a predetermined interval from the outer peripheral surface of the permanent magnet, and a coil wound around the core; And the stator A partition wall disposed on the peripheral surface for restricting the fluid on the rotor side from flowing into the stator side; and a concave portion recessed in the direction of the rotation axis on the surface perpendicular to the rotation axis of the rotor. Is formed.
According to the first aspect, when the rotor rotates by controlling the energization of the coil, the impeller also rotates, and the fluid circulates according to the rotation of the impeller. When the fluid circulates, the partition wall is filled with the fluid, so that the rotor rotates while the rotor and the bearing are submerged in the fluid. If foreign matter such as metal powder is mixed in the fluid that has entered the drive chamber via the bearing, the metal powder adheres to the permanent magnet by magnetic force. Here, since the fluid flows from the high pressure side to the low pressure side, it flows from the discharge port side to the suction port side when the impeller rotates. Therefore, the fluid flows in the direction in which the concave portion formed on the side surface of the permanent magnet is formed, and the metal powder easily adheres to the concave portion. As a result, the amount of metal powder adhering to the outer peripheral surface of the permanent magnet is reduced, so that it is possible to prevent the metal powder from clogging between the partition walls and the permanent magnet and hinder the rotation of the rotor.

In addition to the structure of the first aspect, a concave portion of the permanent magnet is formed on the side surface on the first bearing side so that fluid can flow from the pump chamber to the drive chamber and the size of the permanent magnet is smaller than the radial size of the concave portion. If a communication hole having a small diameter opening position is provided, the fluid that has entered from the communication hole first flows into the recess. Therefore, most of the metal powder in the fluid adheres to the inner peripheral surface of the concave portion, and the amount of the metal powder adhering to the outer peripheral surface of the permanent magnet can be reduced as much as possible.

[0006] Further, as set forth in claims 3 to 5,
When a partitioning mechanism is provided on the partition wall for partitioning the distance between the partition wall and the outer peripheral surface of the permanent magnet into a first interval and a second interval smaller than the first interval, the rotation of the rotor makes it possible to arbitrarily set the outer peripheral surface of the permanent magnet. When the location is switched from the first interval to the second interval, the metal powder attached to the partition wall side from the second interval among the metal powder attached to the outer peripheral surface of the permanent magnet changes from the first interval to the second interval. The permanent magnet is peeled off from an arbitrary position by the switching surface of the permanent magnet. The metal powder peeled from the outer peripheral surface of the permanent magnet is the first
Is stored on the switching surface from the interval of the second interval to the second interval.
In this manner, interference of the partition wall with metal powder adhering between the outer peripheral surface of the permanent magnet and the partition wall can be suppressed, and damage to the partition wall by the metal powder can be suppressed as much as possible. Further, when the first interval or the second interval is formed spirally along the inner peripheral surface of the partition wall as described in claims 6 and 7, the fluid generated near the outer peripheral surface of the permanent magnet when the rotor rotates. Due to this flow, a force toward the axial direction of the rotor acts on the metal powder stored on the switching surface from the first interval to the second interval to discharge the metal powder toward the end of the permanent magnet. The metal powder discharged to the end of the permanent magnet adheres to the side surface of the permanent magnet, thereby making it possible to further suppress damage to the partition walls due to the metal powder.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. Embodiments of the present invention will be described using an electric fluid pump used for cooling an engine or a radiator of an automobile.

FIG. 1 is a sectional view of an electric fluid pump 1 according to the first embodiment. The electric fluid pump 1 includes a housing 2 having a suction port 2a for sucking fluid and a discharge port 2b for discharging fluid, a rotor 5 having an impeller 3 at one end and a permanent magnet 4 fixed to the outer periphery, and an impeller 3; The rotor 5 is rotatably supported with respect to the housing 2 and is disposed between the permanent magnets 4. The pump chamber 12 that houses the impeller 2 and communicates with the suction port 2 a and the discharge port 2 b and houses the permanent magnet 4. A first sliding bearing 6A as a first bearing that partitions the inside of the housing 2 with the driving chamber 11 that performs the rotation, and a first sliding bearing 6A provided at the other end of the rotor 5 to rotatably support the rotor 5 with respect to the housing 2. Second sliding bearing 6B as two bearings
And a stator 9 composed of a core 7 disposed on the inner periphery of the housing 2 and a coil 8 wound on the core 7, and a fluid disposed on the inner peripheral surface of the stator 9 on the rotor 5 side. And a partition wall 10 for restricting the inflow to the stator 9 side. In the first embodiment, the sliding bearing is used as the first bearing and the second bearing, but another bearing such as a rolling bearing may be used.

On the side surface perpendicular to the rotation axis of the permanent magnet 4,
A recess 13 is formed in the outer peripheral surface of the permanent magnet 4 to be recessed in the axial direction. The recess 13 is located on the first side of the side surface on the impeller 3 side.
A concave portion 13A and a second concave portion 13B opposite to the impeller 3 are formed. The housing 2 is provided with a communication hole 14 through which fluid can flow from the pump chamber 12 to the drive chamber 11.
First recess 13A formed on the side surface of first sliding bearing 6A
Is set smaller than the radial opening position of the communication hole 14.

FIG. 2 is a view A of the rotor 5 and the spacing mechanism in FIG. 1, and FIG. 3 is a view B of the rotor 5 and the spacing mechanism in FIG. The partition 10 has a first distance L1 between the partition 10 and the outer peripheral surface of the permanent magnet 4 in the radial direction.
And a second interval L2 smaller than the first interval L1. The interval partitioning mechanism includes a partition member 15 made of a synthetic resin, and the partition 10 is formed such that an outer peripheral area of the permanent magnet 4 facing the first interval L1 is larger than an outer peripheral area of the permanent magnet 4 facing the second interval L1. It is spirally attached to the inner peripheral surface, and defines a first interval L1 and a second interval L2.

The housing 2 has a suction port 2 for sucking a fluid.
a and a pump side housing 2A forming a pump chamber 12 having a discharge port 2b for discharging the sucked fluid, and a body side housing 2B supporting the rotor 5 via sliding bearings 6A and 6B. And the pump side housing 2A
And the body side housing 2B are fixed by bolts 16.

The stator 9 is fixed to the inner periphery of the body side housing 2B and has a core 7 having six protrusions 7a protruding toward the rotation axis of the rotor 5, and each protrusion 7a of the core 7.
The coil 8 is connected to the power supply controller 17 to control the supply of power from a battery (not shown). N pole and S
A permanent magnet 4 in which four poles are alternately formed is fixed.

The operation of the electric fluid pump 1 according to the first embodiment will be briefly described. When a fluid is supplied to a radiator or an engine (not shown), the power supply to each coil 8 is controlled by the power supply control device 17. For example, when a current is applied to a predetermined coil 8 to form a magnetic pole at a predetermined protrusion 7 a, a magnetic attraction force acts between the permanent magnet 4 and the rotor 5 to rotate. At this time, if a current is applied to the other coil 8 in the opposite direction to form a magnetic pole on the other protruding portion 7a, a magnetic repulsive force acts between the protruding portion 7a and the permanent magnet 4 to cause the rotor 5 to rotate. Rotation is promoted. Next, when the current flowing through the coil 7 is switched in the opposite direction, the magnetic attraction force and the magnetic repulsion force with the permanent magnet 4 are also switched, and the rotor 5 further rotates. In this way, by controlling the energization of the coil 8 by the energization control device 17, the rotation of the rotor 5 can be arbitrarily controlled. For example, when the magnitude of the current flowing through the coil 8 is controlled, the magnitude of the magnetic attraction force and the magnetic repulsion force acting between the protruding portion 7a and the permanent magnet 4 is controlled, so that an arbitrary rotational torque can be obtained. 8
An arbitrary rotation speed can be obtained by controlling the switching speed of the power supply to the motor.

As described above, when the rotor 5 is rotated, the impeller 3 at the tip of the rotor 5 rotates, so that fluid flows in from the discharge port 2b on the high pressure side and flows out to the suction port 2a. . The fluid flowing out of the suction port 2a flows through the engine or the radiator to cool the engine.

When the impeller 3 rotates and fluid flows into the communication hole 14 from the discharge port 2b, the metal powder in the fluid that has flowed first adheres to the inside of the first recess 13A, and the fluid further flows into the partition wall 10A.
And flows into the second sliding bearing 6B through the gap between the magnet and the permanent magnet 4. Here, if the metal powder that has not adhered in the first recess 13A is mixed in the fluid flowing through the gap between the outer peripheral surface of the permanent magnet 4 and the partition 10, the metal powder adheres to the outer peripheral surface of the permanent magnet 4. . An arbitrary portion of the outer peripheral surface of the permanent magnet 4 switches from the first interval L1 to the second interval, that is, the partition member 15
Is reached, the metal powder adhering to the partition 10 side from the second interval L2 among the metal powder adhering to the outer peripheral surface of the permanent magnet 4 is peeled off from an arbitrary portion of the permanent magnet 4 by the partition member 15. The metal powder that has peeled off from the outer peripheral surface of the permanent magnet 4 is stored on the side surface of the partition member 15. However, when the rotor 5 rotates, the fluid generated near the outer peripheral surface of the permanent magnet 4 flows from the first space L1 to the second space L1. The force toward the axial direction of the rotor 5 acts on the metal powder stored on the switching surface to the interval L2 of
The metal powder is discharged toward the recess 13B. Therefore, interference of the partition wall 10 by metal powder adhering between the outer peripheral surface of the permanent magnet 4 and the partition wall 10 is suppressed, and damage to the partition wall 10 by the metal powder can be prevented.

In the first embodiment, as shown in FIG. 4, the engine and the suction port 2 of the housing 2 of the electric fluid pump 1 are used.
A metal powder adhering magnet 19 is mounted in the fluid passage 18 to a. The metal powder-adhered magnet 19 has a bolt shape, and the metal powder-adhered magnet 19 is disposed in the fluid passage 18 by screwing the metal powder-adhered magnet 19 into a screw hole 18 a provided in the fluid passage 18. It is. Screw hole 1
An elastic member 20 for urging the metal powder-adhered magnet 19 in a direction protruding from the screw hole 18a, and an elastic member so as to close the screw hole 18a when the metal powder-adhered magnet 19 is removed from the fluid passage 18 are provided on the surface 8a. Valve plate 21 attached to end of member 20
And

According to this configuration, the metal powder mixed into the fluid flowing from the engine to the electric fluid pump 1 adheres to the metal powder adhesion magnet 19, and the metal powder is contained in the fluid flowing into the electric fluid pump 1. It is configured not to be included. In order to remove the metal powder attached to the metal powder attached magnet 19, it is necessary to remove the metal powder attached magnet 19. When the metal powder-adhered magnet 19 is removed, the elastic force of the elastic member 20 causes the valve plate 2
1 closes the screw hole 18a, and leakage of the fluid in the fluid passage 18 to the outside is suppressed as much as possible.

Next, a second embodiment of the present invention will be described. FIG. 5 is a cross-sectional view of the electric fluid pump 31 according to the second embodiment, FIG. 6 is a C view of the rotor 35 and the spacing section mechanism in FIG. 5, and FIG. 7 is a rotor 35 in FIG.
And FIG. The second embodiment is different from the first embodiment in that a first partitioning mechanism using a spacing section mechanism is used.
Is different only in the interval L31 and the second interval L32, and the other configuration is the same.

In the second embodiment, the first distance L31
The spacing section mechanism is formed such that the outer peripheral area of the permanent magnet 34 facing the second interval L32 is smaller than the outer peripheral area of the permanent magnet 34 facing the second interval L32. The spacing section mechanism is a partition 4
0 is spirally deformed radially outward, and the metal powder in the fluid flowing from the communication hole 44 first adheres to the inside of the first recess 43A and is further rotated. The outer surface of the permanent magnet 34 and the partition 4
Metal powder in the fluid flowing through the gap with zero is stored in the partition recess 45. Since the partitioning recess 45 has a spiral shape, a force directed in the axial direction of the rotor 35 acts on the metal powder stored in the partitioning recess 45 due to the flow of the fluid generated near the outer peripheral surface of the permanent magnet 34, The metal powder is discharged toward the second recess 43B. Therefore, as in the first embodiment, the interference of the partition wall 40 by the metal powder adhering between the outer peripheral surface of the permanent magnet 34 and the partition wall 40 is suppressed, and the partition wall 40 of the metal powder is suppressed.
Can prevent damage.

Although the embodiments of the present invention have been described above, the present invention is not intended to be limited to the above-described embodiments, and what kind of electric fluid pump according to the gist of the present invention is applicable. May be something.

[0021]

According to the first aspect, the fluid flows in the direction in which the concave portion formed on the side surface of the permanent magnet is formed, and the metal powder easily adheres to the concave portion. As a result, the amount of metal powder adhering to the outer peripheral surface of the permanent magnet is reduced, so that it is possible to prevent the metal powder from clogging between the partition walls and the permanent magnet and hinder the rotation of the rotor.

According to the second aspect, the fluid that has entered through the communication hole first flows into the recess. Therefore, most of the metal powder in the fluid will adhere to the inner peripheral surface of the concave portion,
This is preferable because metal powder adhering to the outer peripheral surface of the permanent magnet can be reduced as much as possible.

According to the third to fifth aspects, when any part of the outer peripheral surface of the permanent magnet is switched from the first interval to the second interval by the rotation of the rotor, the metal powder adhered to the outer peripheral surface of the permanent magnet. Among them, the metal powder adhering to the partition side from the second interval is peeled off from an arbitrary portion of the permanent magnet by the switching surface from the first interval to the second interval. The metal powder peeled off from the outer peripheral surface of the permanent magnet is stored on the switching surface from the first interval to the second interval. In this manner, interference of the partition wall with metal powder adhering between the outer peripheral surface of the permanent magnet and the partition wall can be suppressed, and damage to the partition wall by the metal powder can be suppressed as much as possible.

Further, according to the sixth and seventh aspects, the metal stored on the switching surface from the first interval to the second interval due to the flow of the fluid generated near the outer peripheral surface of the permanent magnet when the rotor rotates. A force acting on the powder in the axial direction of the rotor acts to discharge the metal powder toward the end of the permanent magnet. The metal powder discharged to the end of the permanent magnet adheres to the side surface of the permanent magnet, thereby making it possible to further suppress damage to the partition walls due to the metal powder.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electric fluid pump according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a view as viewed from B in FIG. 1;

FIG. 4 is a sectional view of a fluid passage according to the first embodiment.

FIG. 5 is a sectional view of an electric fluid pump according to a second embodiment of the present invention.

FIG. 6 is a sectional view taken along the line CC of FIG. 5;

FIG. 7 is a view as viewed in the direction D of FIG. 5;

[Explanation of symbols]

1, 31 ... electric fluid pump 2 ... housing 3 ... impeller 4, 34 ...
-Permanent magnet 5-Rotor 6-Bearing 7-Core 8-Coil 9-Stator 10-Partition wall 11-Drive room 12-Pump room 13A-・ First recess 13B
2nd recessed part 14,44 ... Communication hole 15 ... Partition member (spacing division mechanism) 17 ... Electrification control device 18 ... Fluid passage 19 ... Metal powder adhesion magnet 20 ... Elastic member 21 ... Valve plate 45 ... Division recess (interval division mechanism)

Claims (7)

[Claims] 1. A housing having a fluid inlet and a fluid outlet, a rotor having an impeller fixed to one end and a permanent magnet fixed to an outer peripheral surface, and a rotor disposed between the impeller and the permanent magnet. A rotor is rotatably supported with respect to the housing, and the interior of the housing is communicated with the suction port and the discharge port to form a pump chamber that houses the impeller and a drive chamber that houses the permanent magnet. A first bearing disposed at the other end of the rotor and rotatably supporting the rotor with respect to the housing; and a second bearing fixed to the drive room wall of the housing and facing the rotor. A stator comprising a core having a plurality of protrusions projecting radially inward and extending in the axial direction at a predetermined distance from the outer peripheral surface of the permanent magnet, and a coil wound around the core; Within And a partition wall disposed on a surface of the rotor to restrict the fluid on the rotor side from flowing into the stator side. An electric fluid pump, wherein a concave portion that is concave in a center direction is formed. 2. The housing is provided with a communication hole through which fluid can flow from the pump chamber to the driving chamber, and a radial opening position of the communication hole is defined by a radial direction of a concave portion formed on a side surface on the first bearing side. The electric fluid pump according to claim 1, wherein the diameter is smaller than the dimension. 3. The partition wall is provided with an interval partitioning mechanism for partitioning a radial interval between the partition wall and the outer peripheral surface of the permanent magnet into a first interval and a second interval smaller than the first interval. The electric fluid pump according to claim 1, wherein: 4. The space separating mechanism according to claim 1, wherein the first gap and the second gap are arranged such that an outer peripheral area of the permanent magnet facing the first interval is larger than an outer peripheral area of the permanent magnet facing the second interval. The electric fluid pump according to claim 3, wherein the electric fluid pump is partitioned. 5. The space separating mechanism according to claim 1, wherein the first gap and the second gap are arranged such that an outer peripheral area of the permanent magnet facing the first interval is smaller than an outer peripheral area of the permanent magnet facing the second interval. The electric fluid pump according to claim 3, wherein the electric fluid pump is partitioned. 6. The interval partitioning mechanism defines a first interval and a second interval so that the first interval is spirally formed along the inner peripheral surface of the partition wall. Claim 4
Electric fluid pump. 7. The interval defining mechanism defines a first interval and a second interval so that the first interval is spirally formed along the inner peripheral surface of the partition wall. Claim 5
Electric fluid pump.