JP4013621B2 - Electric water pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric water pump for circulatingly supplying cooling water to a heat generating device such as a combustion engine of an automobile.
[0002]
[Prior art]
In an automobile equipped with a combustion engine, it is necessary to circulate and supply cooling water to the engine, and this cooling water is supplied by a water pump.
The electric water pump rotates an impeller by an electric motor instead of an automobile engine, and the conventional electric water pump is configured as a centrifugal pump that discharges cooling water in a centrifugal direction by the impeller.
[0003]
[Problems to be solved by the invention]
However, the centrifugal pump has a problem that the pump efficiency is low and the pump efficiency is about 60%. In addition, in the centrifugal pump, since the water flow is discharged in the centrifugal direction, it is necessary to enlarge the housing of the water pump in the centrifugal direction, which has been an obstacle in mounting the vehicle.
Therefore, an object of the present invention is to provide an electric water pump that can improve pump efficiency and can be made compact.
[0004]
[Means for Solving the Problems]
The present invention is an electric water pump including an electric motor and a blade portion that is rotationally driven by the electric motor, and is configured as an axial flow pump that generates an axial flow of cooling water by the rotation of the blade portion. The rotation axis of the part and the rotation axis of the electric motor are coaxially arranged, and the electric motor is coaxially arranged inside the blade part .
[0005]
According to the present invention, the electric water pump is configured as an axial flow pump, and the axial flow pump is superior in pump efficiency as compared with a centrifugal pump, so that improvement in pump efficiency can be achieved.
Moreover, since the cooling water flows in the axial direction, it is not necessary to increase the pump diameter as in the case of a centrifugal pump. Furthermore, since the axial center of the blade that generates the axial flow and the axial center of the electric motor are coaxially arranged, the direction of the cooling water flowing through the blade matches the axial direction of the electric motor, and an electric motor is provided. However, the pump diameter can be prevented from increasing, and the size can be reduced.
[0006]
In addition, the electric motor is coaxially arranged inside the blade portion, and thus, by providing the electric motor inside the blade portion, the axial length of the pump can be reduced, and further downsizing can be achieved. Can be planned.
[0008]
And the said blade | wing part has a shaft part and the spiral blade provided in the said shaft part, and it is preferable that the front-end | tip part and the rear-end part are streamline. Since the shaft tip and rear ends are streamlined, the resistance when cooling water flows is reduced, the water flow is stabilized, and the pump efficiency is improved.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an electric water pump 1 according to the first embodiment. The water pump 1 is mounted on an automobile and circulates and supplies cooling water that cools heat-generating equipment such as an automobile engine.
[0010]
The water pump 1 includes a cylindrical housing 7 having a cooling water suction port 3 and a discharge port 5. A blade portion 9 is installed in the housing 7, and an electric motor 11 for rotating the blade portion 9 is attached outside the housing 7. The electric motor 11 is connected to a power source (not shown) through the connector 11a.
[0011]
The housing 7 and the electric motor 11 are juxtaposed in the axial direction of the electric motor rotating shaft 13. The housing 7 and the electric motor 11 have substantially the same diameter, and the overall shape obtained by combining both the members 7 and 11 is a cylindrical shape.
[0012]
In the housing 7, a cooling water flow path 15 is formed for the cooling water to flow in the axial direction. The cooling water flowing from the suction port 3 provided on one end side in the axial direction of the housing 7 In the axial direction, and flows out from the discharge port 5 provided on the other axial end side of the housing 7. Here, the suction port 3 is provided on one end surface in the axial direction of the housing 7, while the discharge port 5 is provided on the outer peripheral surface of the housing 7. That is, the suction port 3 opens in the axial direction of the housing 7, but the discharge port 5 opens in a direction orthogonal to the axial direction of the housing 7. Therefore, the cooling water flowing in the axial direction in the housing 7 curves toward the discharge port 5 in the vicinity of the discharge port 5. In addition, in FIG. 1, although the discharge port 5 is drawn smaller than the suction port 3, it is preferable that it is comparable magnitude | size.
[0013]
A hole 16 through which the rotation shaft 13 of the electric motor 11 is inserted is formed in the other axial end surface 7 b of the housing 7. The electric motor 11 is provided on the other end side of the housing 7 in the axial direction, and the rotating shaft 13 is inserted into the cooling water passage 15 through the hole 16.
[0014]
The blade portion 9 includes a shaft portion 17 whose axial direction is directed in the longitudinal direction of the cooling water passage 15 and a spiral blade 19 provided on the outer peripheral surface of the shaft portion 17 in the middle portion of the cooling water passage 15. The shaft flow is generated by rotation to send the cooling water in the direction of the shaft portion 17, that is, in the longitudinal direction of the cooling water flow path 15. That is, this pump 1 is an axial pump. Since it is an axial flow pump, the pump efficiency is as high as about 80 to 90%, and high efficiency can be achieved. The axial flow of the cooling water generated by the blade portion 9 flows out from the discharge port 5 located on the downstream side of the blade portion 9.
[0015]
The shaft portion 17 has a streamlined tip portion 17a so that the resistance to water flow is reduced. Further, the rear end portion 17b of the shaft portion 17 is also formed in a streamline shape, and the effect of reducing the resistance of water flow is also obtained in this rear end portion 17b. Thus, by forming both the front-end | tip part 17a and the rear-end part 17b of the axial part 17 in a streamline shape, a resistance reduction effect can be heightened further, a water flow is stabilized and pump efficiency improves. The rear end portion 17 b of the shaft portion 17 is connected to the rotating shaft 13 extending from the electric motor 11 provided outside the housing 7. In order to prevent the cooling water from leaking from the hole 16, the hole 16 is provided with a seal member 21 such as a mechanical seal or a rubber seal.
[0016]
In addition to the blade portion 9 which is a moving blade, the housing 7 is provided with a stationary blade 23 for preventing the vortex from being generated by the rotation of the blade portion 9. In FIG. 1, the stationary blade 23 is provided on the upstream side of the blade portion 9, but can also be provided on the downstream side.
[0017]
According to the electric water pump 1 according to the present embodiment, since the power source of the pump 1 is an electric motor, only energy corresponding to the required amount of cooling water is required, and the fuel efficiency of the automobile is improved. Moreover, since the electric water pump 1 is configured as an axial flow pump, and the axial flow pump is highly efficient at high rotation, a motor with high rotation and low torque can be used, and a small and inexpensive electric water pump 1 can be used. Become.
[0018]
Further, since the blade portion 9 generates an axial flow, it is not necessary to increase the diameter of the housing unlike a centrifugal pump, and the diameter of the housing 7 is reduced to the size of the blade portion 9 to reduce the cross-sectional area. can do. Further, since the rotation axis 17b of the blade portion 9 and the rotation axis 13a of the electric motor rotation shaft 13 are coaxially arranged, the diameter does not increase even if the electric motor 11 is provided. In particular, since the cylindrical housing 7 and the electric motor 11 are coaxially arranged side by side, the overall shape of the pump is small and simple.
[0019]
Therefore, if this electric water pump 1 is mounted on an automobile, the pump 1 can be installed in a space that forms part of the circulation path of the cooling water without requiring a large space like a centrifugal pump. The degree of freedom increases. For example, the water pump 1 can be attached in the middle of a cooling water circulation pipe, and can also be attached to an engine water jacket or a radiator.
[0020]
FIG. 2 shows an electric water pump 31 according to the second embodiment. The water pump 31 includes a cylindrical housing 37 having mounting flanges 33 and 35 at both axial ends. One end of the housing 37 in the axial direction is a cooling water suction port 39, while the other end in the axial direction is a cooling water discharge port 41, and the cooling water can flow in the housing 37 in the axial direction. it can.
[0021]
In the middle of the cooling water flow path 43 in the housing 37, a blade portion 45 that generates an axial flow is provided. The blade portion 45 includes a shaft portion 47 whose tip is streamlined and a spiral blade 49 provided on the outer periphery of the shaft portion 47. The shaft portion 47 is provided with a rotation support shaft 51 coaxially. Both ends in the axial direction of the rotation support shaft 51 are rotatably supported via a dynamic pressure bearing 53. A slide bearing may be adopted as the bearing of the rotation support shaft 51. When a rolling bearing is used as the bearing, there is a risk that grease as a lubricant may flow out and lower in viscosity due to cooling water, but such a problem can be avoided by employing a dynamic pressure bearing or a sliding bearing. The hydrodynamic bearing is a kind of a sliding bearing.
[0022]
The member that supports the rotation support shaft 51 on the suction port 39 side is a support column 55 provided at the suction port 39 of the housing 37, and a plurality of support columns 55 are provided at equal intervals in the suction port 39. The cooling water can enter the housing 37 through the gap between the columns 55.
[0023]
A member that supports the rotation support shaft 51 on the discharge port 41 side is a support base member 57 provided in the vicinity of the discharge port 41 of the housing 37. The support base member 57 is attached to the inner peripheral surface of the housing 37, and the cooling water can reach the discharge port 41 through the circulation hole 59 provided on the outer peripheral side of the support base member 57.
[0024]
In the second embodiment, the electric motor 61 for rotationally driving the blade portion 45 is provided coaxially with the blade portion 45 inside the blade portion 45. The electric motor 61 is configured as a brushless motor and can also perform sensorless control.
[0025]
In order to house the electric motor 61 inside, the inside of the shaft portion 47 of the blade portion 45 is formed in a hollow shape. The rotary support shaft 51 passing through the shaft 47 is provided with a permanent magnet 63 on the rotor side, and the electromagnet holding portion 65 extending from the support base member 57 into the shaft 47 is provided with an electromagnet 67 on the stator side. It has been. By the operation of the electric motor 61, the rotation support shaft 51 that is a rotor rotates, and the blade portion 45 rotates to generate an axial flow. Therefore, the cooling water flows around the blade portion 45 to cool the blade portion 45, and the motor 61 provided therein is effectively cooled. That is, the blade part 45 functions like a cooling fin.
[0026]
The permanent magnet 63 and the electromagnet 67 have waterproof portions 63a and 67a formed by resin molding, respectively, to ensure waterproofness. Therefore, there is no problem even if cooling water enters the blade portion 45. Moreover, since the electric motor 61 will be in a submerged state because cooling water approachs into the blade part 45, the motor cooling effect by cooling water further increases.
[0027]
Due to these excellent motor cooling effects, even if the electric water pump 1 of this embodiment is arranged near the heating element of an automobile engine or transmission, the motor performance is not inferior. Even if it is used, high-capacity cooling water can be pumped. Furthermore, since the electromagnet 67 is provided on the stator side, wiring to the electromagnet 67 is easy.
[0028]
In addition, by arranging the electric motor 61 inside the blade portion 45, the axial length of the pump 31 is shortened, and further compactization is possible. In addition, since the suction port 39 and the discharge port 41 are formed on both end surfaces in the axial direction of the cylindrical housing 37, the flow of the cooling water is linear, the resistance is low, and the pump efficiency is high.
[0029]
FIG. 3 shows an electric water pump 71 according to the third embodiment. The electric water pump 71 has a configuration in which a blade portion 75 is coaxially provided inside the electric motor 73. The electric water pump 71 has a bottomed cylindrical housing main body 77 and a lid 79 provided so as to close an opening on one end side in the axial direction of the housing main body 77. A through-hole serving as a cooling water suction port 81 is formed in the lid 79, and a through-hole serving as a cooling water discharge port 82 is formed in the bottom 77 a of the housing body 77. Therefore, the cooling water can flow in the axial direction within the housing body 77.
[0030]
An electromagnet 83 on the stator side is provided on the inner peripheral surface of the housing body 77. A permanent magnet 85 on the rotor side is arranged inside the electromagnet 83. The permanent magnet 85 is attached to the outer peripheral portion of the blade portion 75, and the blade portion 75 rotates integrally with the rotation of the permanent magnet 85 to generate an axial flow.
[0031]
The blade portion 75 includes a spiral blade 89 on the outer periphery of the shaft portion 87, and the spiral blade 89 is coupled to the inside of the permanent magnet 85. Both ends in the longitudinal direction of the shaft portion 87 are rotatably supported by the lid body 79 or the housing main body bottom portion 77a via the dynamic pressure bearing 91.
[0032]
The inner side of the permanent magnet 85 is an internal flow path 91 through which the cooling water entering from the suction port 81 flows, and the axial flow of the cooling water is generated by the rotation of the blade portion 75. Since the cooling water flows through the electric motor 71, the electromagnet 83 and the permanent magnet 85 are formed with waterproof portions 83a and 85a by resin molding, respectively.
[0033]
In the electric water pump 71 according to the third embodiment, since the blade portion 75 is coaxially arranged inside the electric motor 73, the axial length of the pump 1 can be reduced. In addition, since the cooling water flows inside the electric motor 73, the electric motor 73 can be effectively cooled. In addition, since the cooling water can also flow through the space between the electromagnet 83 and the permanent magnet 85, the flow path can be widened, the pressure loss of the flowing water is small, and the pump efficiency is high.
[0034]
FIG. 4 shows an electric water pump 71 according to the fourth embodiment. The fourth embodiment is common to the third embodiment, but the main difference is that the shaft portion 87 is omitted and the cylindrical permanent magnet 85 forms a substantial shaft portion. is there. The outer peripheral surface of the permanent magnet 85 (the waterproof portion 85a) serving as the shaft portion is rotatably supported by a dynamic pressure bearing 93 formed between the inner periphery of the electromagnet 83 (the waterproof portion 83a). In 4th Embodiment, since the axial part 87 of 3rd Embodiment is abolished, the suction port 81 and the discharge port 82 can be formed largely, and the distribution | circulation efficiency of cooling water is good. In addition, since it is not necessary to provide a separate rotation support shaft, the structure becomes simple and the failure of the pump can be reduced. Further, since the outer diameter of the permanent magnet 85 having the inner flow path on the inner peripheral side can be made larger than the outer diameter of the shaft portion of the third embodiment, the load capacity of the dynamic pressure bearing 93 is increased and the pump Can rotate smoothly.
In addition, the point which abbreviate | omitted description in 4th Embodiment is the same as that of 3rd Embodiment, and the same code | symbol is attached | subjected to the member which is common in drawing.
[0035]
The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the matters described in the claims.
[0036]
【The invention's effect】
According to the present invention, since the electric water pump is configured as an axial flow pump, the pump efficiency can be improved, and the rotation axis of the electric motor and the rotation axis of the blade portion are provided coaxially. The pump can be made compact.
In addition, since the electric motor is coaxially arranged inside the blade portion , the axial length of the pump can be reduced, and further downsizing can be achieved .
Et al is, when the shaft tip portion and the rear portion of the blade part is streamlined, the water flow is stabilized with resistance when the cooling water flows is reduced, the pump efficiency is improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an electric water pump according to a first embodiment.
FIG. 2 is a cross-sectional view of an electric water pump according to a second embodiment.
FIG. 3 is a cross-sectional view of an electric water pump according to a third embodiment.
FIG. 4 is a sectional view of an electric water pump according to a fourth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electric water pump 9 Blade | wing part 11 Electric motor 13a Rotating shaft center 17 Shaft part 17a Shaft part front-end | tip part 17b Shaft part rear end part 17c Rotating shaft center 19 Spiral blade 31 Electric water pump 45 Blade part 47 Shaft part 49 Spiral blade 61 Electric Motor 71 Electric water pump 75 Blade portion 87 Shaft portion 89 Spiral blade 91 Internal flow path

Claims (2)

In an electric water pump comprising an electric motor and a blade portion that is rotationally driven by the electric motor,
It is configured as an axial flow pump that generates an axial flow of cooling water by the rotation of the blade portion,
The rotation axis of the blade part and the rotation axis of the electric motor are arranged coaxially ,
The electric water pump , wherein the electric motor is coaxially disposed inside the blade portion . The blade portion has a shaft portion and a spiral blade provided in the shaft portion,
The electric water pump according to claim 1 , wherein the shaft portion has a streamlined front end portion and rear end portion .

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