JPH09228977A - Water pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the leakage of cooling water in a part where a water pump is installed by providing a stator which supports a cylindrical rotor rotatably and constitutes an electric motor in opposition to the rotor on an outer peripheral face of a case and providing a bladelike part which causes a stream in the axial direction on an inside diameter side of the rotor. SOLUTION: A water pump used for circulating cooling water of an engine for automobile can connect cases 13 made of non-magnetic material in series for a passage of cooling water. A cylindrical rotor 14 made of permanent magnet is supported in a condition in which its displacement in the axial direction is prevented and only rotation is possible in the inside of the case 13. Moreover, a stator 15 is provided in a part which is on an outer peripheral face of the case 13 and opposes to an outer peripheral face of the rotor 14 through the case 13, and the rotor 14 is rotated by conducting electricity to a stator 15 which is a coil. An impeller 16 which is a bladelike part is supported and fixed on the inside diameter side of the rotor 14 to cause a stream in the axial direction due to the rotation of the rotor 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A water pump according to the present invention is used for circulating cooling water for an automobile engine.

[0002]

2. Description of the Related Art A water pump for circulating cooling water for an automobile engine is constructed, for example, as shown in FIG. The cylindrical housing 1 is fixed to a cylinder block of an engine by a mounting flange 2 formed on an outer peripheral surface of an inner end portion (right end portion in FIG. 8). This housing 1
Inside of, a rotating shaft 3 is provided with a bearing 4 such as a double-row ball bearing,
It is rotatably supported. Sealing rings 5 and 5 are provided at both ends of the bearing 4 in the axial direction (left and right direction in FIG. 8) to prevent leakage of grease enclosed therein and leakage of dust and water vapor existing outside. I am trying. Further, at the outer end portion (left end portion in FIG. 8) of the rotary shaft 3 protruding from the outer end (left end portion in FIG. 8) opening of the housing 1, the pulley 6 is provided.
Is fixed. In the assembled state to the engine, a belt (not shown) is stretched over the pulley 6 so that the rotary shaft 3
Is driven to rotate by the crankshaft of the engine. On the other hand, the impeller 7 is fixed to a portion of the inner end portion (right end portion in FIG. 8) of the rotary shaft 3 that protrudes from the inner side surface (right side surface in FIG. 8) of the mounting flange 2. That is, the rotating shaft 3
The hub 8 is externally fitted and fixed to the inner end portion of the, and the impeller 7 is fixed around the hub 8. With the mounting flange 2 fixed to the cylinder block of the engine, the impeller 7 enters the inside of a water jacket provided in the cylinder block. Then, with the rotation of the rotating shaft 3, the cooling water in the water jacket is circulated with a radiator (not shown) or the like.

In the case of the water pump as described above, irrespective of the rotation of the rotating shaft 3 inside the housing 1, the hot water mixed with the steam present in the water jacket is prevented from leaking to the outside. A mechanism is needed. What happens is that if the amount of leakage of hot water becomes excessive, it will be necessary to frequently replenish the cooling water, which is not only troublesome, but also when hot water containing these steams enters the bearing 4 side, This is because the durability of the bearing 4 is adversely affected. Therefore, conventionally, a mechanical seal 9 is provided between the outer peripheral surface of the rotary shaft 3 and the inner peripheral surface of the housing 1 to prevent the hot water mixed with the steam from leaking to the outside. The mechanical seal 9 prevents the hot water containing the steam flowing in the water jacket from leaking to the outside while allowing the rotation of the rotating shaft 3 during the operation of the engine.

Further, a slinger 10 is externally fitted and fixed on the outer peripheral surface of the intermediate portion of the rotary shaft 3 between the bearing 4 and the mechanical seal 9. This slinger 10
The outer peripheral edge of is close to the inner peripheral surface of the housing 1. Also, a part of the housing 1 is used for the slinger 10.
An intake hole 11 is formed on the upper side and an exhaust hole 12 is formed on the lower side of the portion facing the outer peripheral edge. The slinger 10, the intake hole 11 and the exhaust hole 12 are provided to prevent hot water and steam leaked through the mechanical seal 9 from reaching the bearing 4. That is, when the engine is operating, the pressure in the water jacket rises to, for example, about 0.7 to 0.9 kg / cm ² (gauge pressure). Therefore, the hot water containing steam, which flows through the water jacket, passes through the mechanical seal 9 and enters the housing 1 little by little. However, the steam or hot water that has entered the housing 1 in this way is shaken off by the slinger 10 and adheres to the inner peripheral surface of the housing 1, and is discharged from the exhaust hole 12 to the outside of the housing 1. The intake hole 11 supplies outside air into the housing 1 so that steam and hot water are smoothly discharged from the exhaust hole 12.

In the case of the conventional water pump, the cooling water in the water jacket leaks to the outside through the mechanical seal 9, albeit little by little. Therefore, the cooling water decreases as it is used over a long period of time, and it is necessary to replenish the cooling water. Generally, this replenishment interval is very long (unless failure such as overheating or water leakage at the connection occurs). Therefore, as long as the start-up inspection required by the driver is performed, no particular problem will occur. However, it is considered that some drivers do not actually perform the start-up inspection, and in view of the fact that the legal inspection interval has recently been extended from 6 months to 12 months, a structure that can increase the cooling water supply interval Realization of is desired.

In view of measures against exhaust gas and fuel consumption, it is advantageous to keep the temperature of the cooling water at an appropriate value in order to appropriately control the operating condition of the engine. In order to keep the temperature of the cooling water at an appropriate value, the circulation amount of the cooling water by the water pump is set to the cooling water temperature (when feedback control is performed), the accelerator opening, the outside air temperature, and the air passing through the radiator. It is preferable to adjust according to the vehicle speed and the like related to the amount (when performing feedforward control).

A technique for preventing leakage of cooling water through a water pump is disclosed in, for example, Japanese Patent Laid-Open No. 61-7.
As described in Japanese Patent Application Laid-Open No. 2893 and Japanese Patent Application Laid-Open No. 7-208389, a structure utilizing a magnet coupling is conventionally known. In the case of this conventional structure, the drive side permanent magnet connected to the pulley and the driven side permanent magnet connected to the impeller are opposed to each other through the partition wall. Therefore, it is not necessary to penetrate the rotary shaft through the partition wall portion, and the leakage of the cooling water through the penetrating portion can be reliably prevented.

Further, as a technique for adjusting the circulating amount of cooling water by a water pump, for example, Japanese Patent Laid-Open No. 61-61
The structure described in JP-A-79817 is known.
In the case of this conventional structure, the circulation amount is increased / decreased by adjusting the distance between the tip end edge of the impeller and the movable member facing it by turning the solenoid on and off.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the case of the structures described in Japanese Patent Laid-Open No. 3 and Japanese Patent Laid-Open No. 7-208389, it is not possible to adjust the circulating amount of cooling water. Also, if the magnetic coupling goes out of step,
You can't fix this without stopping the engine. That is,
In order to normally transmit the rotational force to the magnet coupling, it is necessary to make the south pole of the drive side permanent magnet face the north pole of the driven side permanent magnet and the north pole of the driven side permanent magnet face the south pole. . On the other hand, when the rotational speed of the engine is rapidly increased and the rotational speed of the drive-side permanent magnet is rapidly increased, the rotational speed of the driven-side permanent magnet fixed to the impeller rotating in the cooling water that is a viscous fluid is increased. Without catching up with this, there is a possibility that out-of-step occurs in which the south poles and north poles of both permanent magnets do not properly face each other. When such a step-out occurs, the magnet coupling part vibrates violently and cannot be restored unless the engine is stopped in order to stop the drive side permanent magnet. Therefore, the structures described in JP-A-61-272893 and JP-A-7-208389 have many problems to be solved in terms of practical use.

Further, in the case of the structure disclosed in Japanese Patent Laid-Open No. 61-79817, regarding leakage of cooling water, FIG.
This is the same as the case of the conventional structure shown in FIG. Further, since it is difficult to finely adjust the circulating amount of the cooling water, it is difficult to maintain the temperature of the cooling water at a predetermined value (it fluctuates around the predetermined value) according to the operating condition of the engine. Further, Japanese Utility Model Laid-Open No. 61-84187 discloses a technique in which a water pump has an axial flow structure provided in the middle of a cooling water pipe, but leakage of a rotating portion is prevented by a pair of mechanical seals. Due to this structure, the prevention of leakage of cooling water is incomplete. In addition, the circulation amount of cooling water cannot be adjusted arbitrarily. The water pump of the present invention was invented in view of such circumstances, and provides a structure capable of eliminating the leakage of cooling water and adjusting the circulating amount arbitrarily.

[0011]

A water pump according to the present invention comprises a cylindrical case made of a non-magnetic material, which is connectable in series to a cooling water passage, and an axial displacement inside the case. A cylindrical rotor that is supported by the outer peripheral surface of the case and that faces the rotor through the case to constitute an electric motor; A wing-shaped portion provided on the inner diameter side and causing a flow in the axial direction of the case with rotation.

[0012]

In the case of the water pump of the present invention configured as described above, the rotor is rotated based on the energization of the stator, and the blade portion provided on the inner diameter side of the rotor is rotated, whereby the inside of the case is rotated. It is possible to induce a cooling water flow in the axial direction. In the case of the water pump of the present invention, since there is no member penetrating the case, it is possible to completely prevent the leakage of cooling water at the water pump installation portion. Further, the rotation speed of the impeller can be arbitrarily adjusted by changing the energization state of the stator that constitutes the electric motor. Therefore, in order to maintain the temperature of the cooling water at a specified value,
It becomes possible to finely adjust the circulating amount of this cooling water.

[0013]

1 to 4 show a first embodiment of the present invention. The case 13 is made of a non-magnetic material such as an aluminum alloy or a heat-resistant synthetic resin into a cylindrical shape, and is connected in series to a passage for cooling water, for example, in the middle of a hose connecting a radiator and a water jacket of an engine. You are free. Inside the case 13, a cylindrical rotor 14 is rotatably supported while being prevented from being displaced in the axial direction (left and right directions in FIG. 1, front and back directions in FIG. 2). In the case of this example, the rotor 14 is made of a permanent magnet, and N poles and S poles are alternately arranged on the outer peripheral surface. Also, on the outer peripheral surface of the case 13, the case 13
In the portion facing the outer peripheral surface of the rotor 14 via
The stator 15 is provided. The stator 15, which is a coil, changes the attraction force and the repulsive force acting between the stator 15 and the rotor 14 based on energization to rotate the rotor 14. That is, the rotor 14 and the stator 15 form an electric motor.

The energization of the stator 15 is controlled by a controller (not shown). To this controller, the detected values of various conditions related to the temperature rise of the cooling water, such as the outside air temperature, the engine speed, the accelerator opening degree, etc., and the detected value of the cooling water temperature itself are input. And this controller, in order to keep the temperature of the cooling water constant in accordance with these detected values,
By adjusting the amount of electricity supplied to the stator 15, the rotor 14
Change the rotation speed of.

An impeller 16 which is a blade portion is supported and fixed on the inner diameter side of the rotor 14 so that the impeller 16 rotates together with the rotor 14. As the impeller 16, a so-called axial flow fan type that causes an axial flow with rotation is used. Further, a rotary shaft 17 is provided at the center of the impeller 16, and both front and rear ends (right and left in FIG. 1) of the rotary shaft 17 are rotatably supported by a pair of front and rear bearing cylinders 25. There is. or,
Each of the bearing cylinders 25, 25 is supported and fixed by a plurality of stays 21 (21 in the illustrated example, 4 in total) at the inner center of both ends of the case 13 respectively.

The outer peripheral surfaces of the front and rear end portions of the rotary shaft 17 are opposed to the inner peripheral surfaces of the bearing tubes 25, 25 with a radial minute gap therebetween. Then, one of these two peripheral surfaces (the outer peripheral surfaces of both ends of the rotary shaft 17 in the illustrated example) on one of the peripheral surfaces is opposed to the radial minute gap as shown in FIG.
Herringbone-shaped radial dynamic pressure groove 1 as shown in (A)
8a or a radial dynamic pressure groove 18b inclined in one direction as shown in FIG. Also, the rotating shaft 17
Both end surfaces of the large diameter portion 19 provided in the intermediate portion of the above and functioning as a hub of the impeller 16 and the inner end surfaces of the bearing cylinders 25, 25 are opposed to each other with a minute thrust clearance therebetween. A herringbone-shaped thrust dynamic pressure groove 20a as shown in FIG. 4 (A) or the same end surface (both end surfaces of the large-diameter portion 19 in the illustrated example) of either of these end surfaces is formed. A thrust dynamic pressure groove 20b inclined in one direction is formed as shown in FIG. The bearing for rotatably supporting the rotary shaft 17 is not limited to the fluid bearing with the dynamic pressure groove,
Sliding bearings are also acceptable.

In the case of the water pump of the present embodiment constructed as described above, when the rotor 14 is rotated based on the energization of the stator 15, the impeller 16 supported on the inner diameter side of the rotor 14 rotates. . When rotating, the radial dynamic pressure groove 18a (or 18b) and the thrust dynamic pressure groove 2
By the action of 0a (or 20b), the outer peripheral surfaces of the front and rear end portions of the rotary shaft 17 and the inner peripheral surfaces of the respective bearing cylinders 25, 25 become the end surfaces of the large diameter portion 19 and the respective bearing cylinders 25, 25.
And the inner end surface of each are in non-contact state. Therefore, the rotation of the rotor 14 and the impeller 16 is smoothly performed with a light force. When the impeller 16 rotates in this manner, an axial flow of cooling water is generated in the case 13.

In the case of the water pump of the present invention, there is no member penetrating the case 13. Therefore, it is possible to completely prevent the leakage of the cooling water at the water pump installation part. Further, the rotation speed of the impeller 16 can be arbitrarily adjusted by changing the energization state of the stator 15 which constitutes the electric motor. Therefore, it becomes possible to finely adjust the circulating amount of the cooling water so as to maintain the temperature of the cooling water at a predetermined value.

Next, FIGS. 5 and 6 show a second embodiment of the present invention. In the case of this example, the spiral groove 22 is formed on the inner peripheral surface of the rotor 14a in which the S poles and the N poles are alternately arranged on the outer peripheral surface of the cylindrical shape, and the blade-shaped portion is formed on the inner peripheral surface of the rotor 14a. Is provided. In addition, stays 21 are respectively provided in the openings at both ends of the rotor 14a and the cylindrical case 13.
a and 21b are provided, and pivot bearings 23 and 23 are provided between the central portions of the stays 21a and 21b.
The rotor 14a has the two pivot bearings 23, 23.
Thus, it is rotatably supported inside the case 13. Further, the stator 1 is attached to the outer peripheral surface of the case 13.
5 are provided.

In the case of this example having such a configuration, when the rotor 14a rotates with the energization of the stator 15, the spiral groove 22 formed on the inner peripheral surface of the rotor 14a causes the axial direction (see FIG. 5). A flow is generated in the left-right direction and the front-back direction in FIG. 6. Also in the case of this example, as in the case of the first example described above, leakage of cooling water can be completely eliminated,
Further, the circulation amount of the cooling water can be finely adjusted.

Next, FIG. 7 shows a third embodiment of the present invention.
An example is shown. In the case of this example, a pair of stays 21
c and 21c at two positions on the inner peripheral surface of the case 13,
These stays 21c, 21 are provided at a distance from each other.
Between c, both ends of the hub 24 in the axial direction (the left-right direction in FIG. 7) are rotatably supported by pivot bearings 23, 23, respectively. A rotor 14b, which has an annular shape and has S poles and N poles alternately arranged on the outer peripheral surface around the hub 24, is provided concentrically with the hub 24, and an inner peripheral surface of the rotor 14b and an outer peripheral surface of the hub 24 are formed. An impeller 16 of an axial fan type, which is a blade portion, is provided therebetween. Further, a stator 15 is provided on the outer peripheral surface of the case 13.

In the case of this embodiment having such a structure, when the rotor 14b rotates in accordance with the energization of the stator 15, the impeller provided between the inner peripheral surface of the rotor 14b and the outer peripheral surface of the hub 24. 16 causes a flow in the axial direction (left and right direction in FIG. 7). Also in the case of this example, as in the case of the above-described first example and the above-described second example, it is possible to completely eliminate the leakage of cooling water and finely adjust the circulating amount of cooling water. In the structure of this example, the bearing for rotatably supporting the hub 24 may be a hydrodynamic bearing constituted by a hydrodynamic groove.

[0023]

Since the water pump of the present invention is constructed and operates as described above, it is possible to prevent the leakage of the cooling water from the installation portion of the water pump, and it is possible to extend the cooling water supply interval. . In addition, it becomes easy to keep the temperature of the cooling water at an appropriate value for measures against exhaust gas and fuel consumption.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a first example of an embodiment of the present invention.

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

FIG. 3B of FIG. 1 showing two examples of the shape of the radial dynamic pressure groove.
Part enlarged view.

FIG. 4 is an end view showing a rotor taken out to show two examples of shapes of thrust dynamic pressure grooves.

FIG. 5 is a schematic cross-sectional view showing a second example of the embodiment of the present invention.

FIG. 6 is an end view showing a rotor and a pivot bearing taken out.

FIG. 7 is a schematic sectional view showing a third example of the embodiment of the present invention.

FIG. 8 is a sectional view showing an example of a conventional structure.

[Explanation of symbols]

 1 Housing 2 Mounting Flange 3 Rotating Shaft 4 Bearing 5 Seal Ring 6 Pulley 7 Impeller 8 Hub 9 Mechanical Seal 10 Slinger 11 Intake Hole 12 Exhaust Hole 13 Case 14, 14a, 14b Rotor 15 Stator 16 Impeller 17 Rotating Shaft 18a, 18b Radial Motion Pressure groove 19 Large diameter part 20a, 20b Thrust dynamic pressure groove 21, 21a, 21b, 21c Stay 22 Spiral groove 23 Pivot bearing 24 Hub 25 Bearing tube

Claims (1)

[Claims] 1. A cylindrical case made of a non-magnetic material, which can be connected in series to a passage of cooling water, and is rotatably supported inside the case while being prevented from axial displacement. Supported by the cylindrical rotor and the outer peripheral surface of the case,
A stator that constitutes an electric motor by facing the rotor through the case, and a wing-shaped portion that is provided on the inner diameter side of the rotor and that causes a flow in the axial direction of the case with rotation are provided. Water pump.