KR101502285B1

KR101502285B1 - Electric Water Pump

Info

Publication number: KR101502285B1
Application number: KR20140147833A
Authority: KR
Inventors: 도민훈; 김경엽; 황양호; 박종원
Original assignee: 지엠비코리아 주식회사
Priority date: 2014-10-29
Filing date: 2014-10-29
Publication date: 2015-03-12

Abstract

The present invention relates to an electric water pump used in an automobile, and more particularly, to an electric water pump capable of enhancing durability and reducing power loss.
An electric water pump according to the present invention includes a housing, a can, a rotary shaft, a lower bearing, an upper bearing, a thrust bearing, a rotor, and an impeller. The can is embedded in the housing. The rotating shaft is mounted inside the can. The lower bearing is press-fitted into a lower portion of the can to support one end of the rotation shaft. The upper bearing is detachably mounted on the upper part of the can to support the other end of the rotary shaft. The thrust bearing is coupled to the rotating shaft to support the upper bearing. The rotor has a thrust bearing fixing part formed by insert injection and fixedly coupling the thrust bearing, and is fixedly coupled to the rotation shaft. The impeller is detachably mounted on a rotary shaft projecting to the outside of the can.
The present invention does not require the use of a rubber cup by injecting and fixing the plastic thrust bearing formed of ceramic. Therefore, the durability of the water pump can be improved.
In addition, according to the present invention, the dimensional tolerance between the housing and the impeller is reduced, and the flow loss can be reduced.

Description

ELECTRIC WATER PUMP [0001]

The present invention relates to an electric water pump used in an automobile, and more particularly, to an electric water pump capable of enhancing durability and reducing power loss.

Generally, a water pump is a device for circulating cooling water to an engine and a heater for cooling the engine and heating the room. The cooling water discharged from the water pump exchanges heat with the engine, the heater, or the radiator, circulates, and then flows back to the water pump. These water pumps are largely divided into mechanical water pumps and electric water pumps. Electric water pumps are widely used which can control the engine cooling in an optimal state and simplify the structure around the engine to improve the fuel efficiency of the vehicle.

Japanese Patent Application No. 10-1072328 discloses a conventional electric water pump, and FIG. 1 is a sectional view of the electric water pump disclosed in the above-mentioned conventional patent.

In the case of the conventional water pump shown in Fig. 1, the upper bearing 7 is mounted between the upper bearing mounting surface 4 and the front end of the rotary shaft 5, And is mounted between the step portion 6 and the upper bearing 7. A thrust bearing (8) is mounted between the cup (9) and the upper bearing (7). That is, the cup 9 relieves the thrust of the rotary shaft 5 from being transmitted to the upper bearing 7, and the thrust bearing 7 reduces the rotational friction of the rotary shaft 5. [

In the case of the water pump, when the impeller 3 is rotated, a lift force is generated, and the impeller 3 receives a force in the direction of the arrow 10. In this case, since the cup 9 is formed of a rubber material, it is contracted and the impeller 3 is moved in the direction of the arrow 10. At this time, if the distance between the impeller 3 and the housing 1 is small, the impeller 3 abuts against the housing 1, and therefore, the interval between the housing 1 and the impeller 3 is made large to prevent this . As a result, a flow loss occurs between the housing 1 and the impeller 3.

Further, the cup 9 has a problem of being worn or broken due to the continuous rotation friction.

The present invention is intended to solve the above problems. An object of the present invention is to provide an electric water pump capable of reducing a flow loss by reducing a gap between a housing and an impeller.

It is another object of the present invention to provide an electric water pump of high durability by not using a cup made of a rubber material.

An electric water pump according to the present invention includes a housing, a can, a rotary shaft, a lower bearing, an upper bearing, a thrust bearing, a rotor, and an impeller. The can is embedded in the housing. The rotating shaft is mounted inside the can. The lower bearing is press-fitted into a lower portion of the can to support one end of the rotation shaft. The upper bearing is detachably mounted on the upper part of the can to support the other end of the rotary shaft. The thrust bearing is coupled to the rotating shaft to support the upper bearing. The rotor has a thrust bearing fixing part formed by insert injection and fixedly coupling the thrust bearing, and is fixedly coupled to the rotation shaft. The impeller is detachably mounted on a rotary shaft projecting to the outside of the can.

In the electric water pump described above, it is preferable that the rotary shaft has a projection for supporting one end of the rotor. The thrust bearing is preferably supported at one end of the thrust bearing and at an outer circumferential surface thereof. Preferably, the thrust bearing fixing portion is insert-injected so as to surround the end portion of the outer circumferential surface of the thrust bearing.

The present invention does not require the use of a rubber cup by injecting and fixing the plastic thrust bearing formed of ceramic. Therefore, the durability of the water pump can be improved.

In addition, according to the present invention, the dimensional tolerance between the housing and the impeller is reduced, and the flow loss can be reduced.

1 is a cross-sectional view of a conventional water pump,
2 is a sectional view of one embodiment of an electric water pump according to the present invention,
FIG. 3 is a cross-sectional view of the can of the embodiment shown in FIG. 2,
Fig. 4 is a cross-sectional view of the inner diameter of the bearing of Fig. 2,
FIG. 5 is a cross-sectional view of the can in which the rotating shaft and the rotor are mounted on the can,
FIG. 6 is a cross-sectional view of the rotor shown in FIG. 2, in which a rotor and a thrust bearing are mounted,
Fig. 7 is a sectional view of the rotor shown in Fig. 2 before insert injection,
Fig. 8 is an exploded perspective view of the water pump shown in Fig. 2,
Fig. 9 is a conceptual view of the upper bearing of the embodiment shown in Fig. 2,
10 is a conceptual view of the can of the embodiment shown in Fig.

An electric water pump according to an embodiment of the present invention will be described with reference to FIGS. 2 to 10. FIG.

The electric water pump according to the present invention includes a housing 110, a can 115, a rotary shaft 120, a lower bearing 125, an upper bearing 130, a thrust bearing 135, a rotor 140 And an impeller 145.

The can 115 is housed in the housing 110. The rotation shaft 120 is mounted inside the can 115 and the protrusion 121 is formed to support one end of the rotor 140.

The lower bearing 125 is press-fitted into the lower portion of the can 115 to support one end of the rotation shaft 120. The upper bearing 130 is detachably mounted on the upper part of the can 115 to support the other end of the rotation shaft 120.

One end of the thrust bearing 135 is supported by the protrusion 121 of the rotation shaft 120 so as to be in contact with the upper bearing 130 and is coupled to the rotation shaft 120 and the outer circumferential surface thereof is formed by cutting.

The rotor 140 is fixedly coupled to the rotating shaft 120 and has a thrust bearing fixing portion 141 for fixing the thrust bearing 135 in a fixed manner. The thrust bearing fixing portion 141 is formed by insert injection so as to enclose and fix the end portion of the outer circumferential surface of the thrust bearing 135 coupled to the rotation shaft 120.

In this embodiment, the thrust bearing 135 has one end supported by the projection of the rotary shaft 120 and the other end abutting the upper bearing 130. In this embodiment, the thrust bearing 135 is formed of ceramic and the upper bearing 130 is formed of plastic. Therefore, even if the thrust bearing 135 is pressed by the rotation of the rotor 140, it is not contracted. Thus, the impeller 145 does not move upward, and the gap between the impeller 145 and the housing 110 is maintained constant. Accordingly, the gap between the impeller 145 and the housing 110 can be reduced. Therefore, the flow loss due to the gap between the impeller 145 and the housing 110 can be reduced. Further, since the thrust bearing 135 is formed of ceramic, since the wear is small, wear and breakage due to continuous rolling friction can be reduced.

In the case of the conventional water pump shown in FIG. 1, the cup 9 is formed of a rubber material and mounted between the rotary shaft 5 and the upper bearing 7. In this case, the cup 9 shrinks when the impeller 3 rotates, and the gap between the housing 1 and the impeller 3 is increased so that the housing 1 and the impeller 3 are not in contact with each other. Therefore, a flow loss occurs between the housing 1 and the impeller 3. In addition, the rubber cup 9 is worn or broken due to subsequent rolling friction.

The impeller 145 is detachably mounted on a rotary shaft 120 protruding outside the can 115.

In this embodiment, the upper bearing 130 is coupled to the upper portion of the can 115 by bolts 131. Meanwhile, in the present embodiment, the upper bearing 130 is integrally formed of plastic. In this case, it is possible to align the center axes of the inner diameters of the lower bearing 125 and the upper bearing 130 to match each other. The lower bearing 125 and the upper bearing 130 are mounted on the can 115 as shown in FIG. 3 and the tool 101 is mounted on the upper bearing 130 and the lower bearing 125 And the inner diameters of the upper bearing 130 and the lower bearing 125 are machined together. The center axes of the inner diameters of the upper bearing 130 and the lower bearing 125 coincide with each other because one tool 101 is inserted into the upper bearing 130 and the lower bearing 125 to process the inner diameter thereof. After machining the inner diameter, the upper bearing 130 is separated and the rotary shaft 120 and the rotor 140 are mounted as shown in FIG. 5, and then the upper bearing 130 is coupled again. Thus, the center axes of the inner diameters of the lower bearing 125 and the upper bearing 130 coincide with each other.

At this time, the bolt 131 is inserted into the bolt hole 132 of the upper bearing 130 and the bolt tap 117 of the can 115 to bind the upper bearing 130 to the upper portion of the can 115. When the upper bearing 130 is fastened to the can 115 by the bolt 131, not all the bolts 131 are fastened together at the same time. Therefore, the position of the upper bearing 130 can be slightly distorted from the upper part of the can 115 when the bolt 131 is fastened. Even if the inner diameter of the upper bearing 130 and the lower bearing 125 are machined together using the tool 101, if the upper bearing 130 is mounted again, the center lines of the upper bearing 130 and the lower bearing 125 do not coincide I can not. A plurality of mounting protrusions 116 are formed in the can 115 so that the upper bearing 130 is always located at a predetermined position on the upper side of the can 115. The mounting shaft 116 A mounting hole 133 is formed in the mounting hole 133. [ Thus, when the upper bearing 130 is positioned on the upper side of the can 115, the mounting protrusion 116 is inserted into the mounting hole 133 to maintain the upper bearing 130 at a constant position. That is, even when the bolt 131 is fastened, the mounting protrusion 116 is inserted into the mounting hole 133 to fix the upper bearing 130 to a predetermined position. Therefore, the center line of the upper bearing 130 and the center line of the lower bearing 125 can coincide with each other. The mounting protrusion 116 is formed on the upper bearing 130 and the mounting hole 133 is formed on the upper bearing 130. However, in the present embodiment, the mounting projection 116 is formed on the can 115 and the mounting hole 133 is formed on the upper bearing 130, May be formed in the can 115. Accordingly, since the center axes of the upper bearing 130 and the lower bearing 125 coincide with each other, the rotation of the rotation shaft 125 can be smoothly performed.

101: tool 110: housing
115: can 116: mounting projection
117: bolt tab 120: rotary shaft
121: projection 125: lower bearing
130: Upper bearing 131: Bolt
132: bolt hole 133: mounting hole
135: thrust bearing 140: rotor
141: thrust bearing fixing portion 145: impeller

Claims

A housing,
A can accommodated in the housing,
A rotation shaft mounted on the inside of the can with a projection formed on an outer circumferential surface thereof,
A lower bearing press-fitted to a lower portion of the can to support one end of the rotary shaft,
An upper bearing detachably mounted on the upper portion of the can to support the other end of the rotary shaft,
A thrust bearing which is supported at one end thereof by the protrusion and whose outer circumferential surface is integrally formed and is coupled to the rotation shaft to support the upper bearing,
A thrust bearing fixing part for insert-molding the end of the outer circumferential surface of the thrust bearing to fix the thrust bearing to the fixed part; a rotor supported by the protrusion and fixedly coupled to the rotation shaft;
And an impeller detachably mounted on a rotating shaft protruding outside the can.

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