JPH09177696A - Water pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent that the steam or the like leaked from a mechanical seal reaches to a bearing, and to improve the durability of the bearing. SOLUTION: A cylinder 29 is provided at the outer peripheral edge of a seal member 28 which is provided between a mechanical seal 9 and a bearing 4. By making the outer peripheral surface of the cylinder 29 and the inner peripheral surface of a housing 1 eccentric, a minute clearance 30 whose thickness size along the circumferential direction is changed gradually is provided between both peripheral surfaces. An exhaust port 27 is provided at the bottom of the housing 1, and the inner periphery side opening of the exhaust port 27 is opposed to the minute clearance 30. The seal member 28 presses out the steam or the like leaked from the mechanical seal 9 and invaded to the minute clearance 30, from the exhaust port 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A water pump according to the present invention is used in a state where it is incorporated in a cylinder block of an engine in order to circulate 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. 13). A rotating shaft 3 is rotatably supported inside the housing 1 by a bearing 4 such as a double-row ball bearing. Sealing rings 5 and 5 are provided at both ends of the bearing 4 in the axial direction (left and right direction in FIG. 13) to prevent leakage of grease enclosed therein and leakage of dust and water vapor existing outside. I am trying. Further, a pulley 6 is fixed to a portion of the outer end portion (left end portion in FIG. 13) of the rotary shaft 3 protruding from the outer end (left end portion in FIG. 13) opening of the housing 1. When assembled to the engine, hang a belt (not shown) around the pulley 6,
The rotary shaft 3 is rotationally driven by the crankshaft of the engine. On the other hand, at the inner end of the rotary shaft 3 (right end in FIG. 13), the inner side surface of the mounting flange 2 (right side in FIG. 13).
The impeller 7 is fixed to the portion protruding from the. That is, the hub 8 is externally fitted and fixed to the inner end portion of the rotary shaft 3, 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 which is a sealing device 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. ing.

In order to configure the mechanical seal 9, a seat ring 11 is provided inside an annular recess 10 formed on the outer end surface (the left end surface in FIG. 13) of the hub 8 with a cushioning material 12 such as heat resistant rubber interposed therebetween. keeping. That is, the seat ring 11 is supported in a state of projecting radially outward from the outer peripheral surface of the rotary shaft 3 toward the inner peripheral surface of the housing 1. One side surface (left side surface in FIG. 13) of such a seat ring 11 is a rotation side sliding surface 13 that is flat over the entire circumference. On the other hand, the support cylinder 14 is internally fitted and fixed to the inner end portion (the right end portion in FIG. 13) of the inner peripheral surface of the housing 1. The support cylinder 14 has a flange-shaped support plate portion 15 that projects inward in the diametrical direction from the inner peripheral surface of the housing 1 toward the outer peripheral surface of the rotary shaft 3. Further, the guide cylinder portion 16 is directed to the inner peripheral edge of the support plate portion 15, and the fitting cylinder portion 17 is directed to the outer peripheral edge thereof, respectively, facing inward (to the right in FIG. 13)
They are formed concentrically with each other. An outward flange-shaped locking flange portion 18 is formed at the end edge portion of the fitting tubular portion 17 among them. In the state where the fitting cylinder portion 17 is fitted and fixed to the inner end portion of the housing 1, the locking flange portion 18 abuts on the inner end surface of the housing 1 and the fitting fixing position of the fitting cylinder portion 17 is obtained. Regulate.

Further, a driven ring 19, a bellows 20, and a compression coil spring 21 are provided on the outside in the diametrical direction of the guide tube portion 16. Driven ring 19 of these
Like the seat ring 11, the whole is made of a heat-resistant slippery material and is formed into an annular shape. The inner end surface, which is one surface (right side in FIG. 13) of the driven ring 19 in the axial direction (right and left direction in FIG. 13), has a width dimension narrowed by axially projecting the outer half portion in the diametrical direction. This protruding portion is used as the fixed-side sliding surface 22. The fixed-side sliding surface 22 is in intimate sliding contact with the rotating-side sliding surface 13 over the entire circumference. The bellows 20 is made of heat-resistant rubber or the like into a generally cylindrical shape, and is provided between the driven ring 19 and the support plate portion 15. The bellows 20 is capable of expanding and contracting in a length dimension in the axial direction (left and right direction in FIG. 13). In addition, the compression coil spring 21
Is provided between an outward flange-shaped locking flange portion 23 formed on the outer peripheral surface of the driven ring 19 and a base portion 24 of the bellows 20 abutting against the support plate portion 15. Therefore, the driven ring 19 is elastically pressed toward the seat ring 11 by the elastic force of the compression coil spring 21.

Since the mechanical seal 9 is constructed as described above, the hot water containing steam flowing in the water jacket is prevented from leaking to the outside while permitting the rotation of the rotary shaft 3 during the operation of the engine. To do. That is, the rotation of the rotary shaft 3 inside the housing 1 is allowed based on the sliding movement of the rotary sliding surface 13 and the stationary sliding surface 22.
Further, since the sliding surfaces 13 and 22 are in intimate sliding contact with each other over the entire circumference, the hot water containing the steam is prevented from leaking out of the water jacket.

Further, a ring-shaped sealing member 25 called a slinger 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 support cylinder 14. The outer peripheral edge of the sealing member 25 is close to the inner peripheral surface of the housing 1. Further, an intake hole 26 is provided above the portion of the housing 1 facing the outer peripheral edge of the sealing member 25.
Similarly, exhaust holes 27 are formed on the lower side. The sealing member 25, the intake hole 26, and the exhaust hole 27 are provided to prevent the hot water and steam leaked through the mechanical seal 9 from reaching the bearing 4. That is, when the engine is operating, the pressure inside the water jacket is, for example, 0.7 to 0.9 kg / cm ² (gauge pressure).
Rise to a degree. 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 blown off by the sealing member 25 and adheres to the inner peripheral surface of the housing 1, and the exhaust hole 27
Is discharged to the outside of the housing 1. The intake hole 26 supplies outside air into the housing 1 so that steam and hot water are smoothly discharged from the exhaust hole 27.

Regarding the water pump, as a publication relating to a technique for preventing water vapor or the like leaking from a mechanical seal from entering a bearing, for example, Japanese Patent Laid-Open Publication No. Hei 5-
No. 99198, No. 5-321888, No. 59-160889, No. 60-167194, No. 61-5398, No. 61-48997-8.
No. 61-51497 and No. 61-6230.
No. 0, No. 61-103596, No. 62-15.
0596, Japanese Utility Model Publication No. 1-125819, 2
There is a publication of -59220 and the like. These publications, including those similar to the conventional structure shown in FIG. 13, disclose a technique for ensuring the durability of the bearing by discharging water vapor leaking from the mechanical seal into the atmosphere. Further, in Japanese Utility Model Application Laid-Open No. 5-19524, an exhaust passage formed at the center of the rotary shaft and having one end open to the atmosphere, and a branch from this exhaust passage, the end of which is the outer periphery of the rotary shaft. A structure is provided in which a branch passage is opened in a part of the surface, and water vapor leaked from the mechanical seal is discharged to the outside through the branch passage and the exhaust passage.

[0009]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention Including the structure described in FIG. 13 and the techniques described in the above publications, water vapor and the like leaked from a mechanical seal, which has been conventionally known, is discharged into the atmosphere. Most of the techniques are for utilizing the centrifugal force and the stirring force to discharge the water vapor and the like leaking from the mechanical seal into the housing to the outside of the housing. With such a structure, the discharge efficiency of water vapor is limited.

On the other hand, in order to further improve the durability of the bearing, the present inventor pressurizes the steam leaking into the housing in order to further reduce the steam remaining in the housing. I thought it would be effective to force it out of the housing. Among the above publications, Japanese Utility Model Laid-Open No. 61-62300 discloses that a centrifugal multi-blade fan-shaped stirring blade is provided at an intermediate portion of a rotary shaft and an inner peripheral surface of a housing is formed in a spiral shape. It describes a structure in which an exhaust hole is opened in the largest diameter portion of the surface. According to such a structure, the water vapor and the like leaking into the housing are forcibly sent out toward the exhaust hole by the stirring blade, so that the water vapor and the like remaining in the housing can be further reduced. become.

[0011] However, such an actual development 61-6230
In the case of the technique described in Japanese Patent Publication No. 0, the machining of the inner peripheral surface of the housing is troublesome and the manufacturing cost increases. Further, since a relatively large amount of outside air is sucked from the outside of the housing and this air is discharged to the outside of the housing together with the steam, the amount of air passing through the housing increases as the stirring blade rotates, and the intake air is increased. It is considered that the noise during operation increases due to the sound and the discharge sound.

The water pump of the present invention has been invented in view of such circumstances, and has a structure capable of efficiently discharging water vapor leaked into the housing without increasing the manufacturing cost and noise during operation. Is provided.

[0013]

Among the water pumps of the present invention, the water pump described in claim 1 is, like the conventional water pump described above, a housing having a cylindrical inner peripheral surface and not rotating. , A rotary shaft supported inside the housing via a bearing, an impeller fixed to a portion of the rotary shaft projecting from an inner end opening of the housing, and an inner circumference of the inner end of the housing. A sealing device such as a mechanical seal, which is provided between the surface and the outer peripheral surface of the intermediate portion of the rotary shaft to close the space between these peripheral surfaces;
An exhaust hole, which is formed in a part of the housing in a state where the inner peripheral surface and the outer peripheral surface of the housing penetrate, and whose inner peripheral surface side opening is located between the sealing device and the bearing, and the exhaust hole. A portion facing the outer peripheral surface of the rotating shaft or the inner peripheral surface of the intermediate portion of the housing, a sealing member having its base end fixed in a state of diametrically projecting from the peripheral surface, The above-mentioned rotating shaft is freely rotatable.

In particular, in the water pump according to the first aspect of the present invention, the peripheral surface of the sealing member on the tip side is a peripheral surface different from the peripheral surface to which the sealing member is fixed. It faces the peripheral surface or the outer peripheral surface of the intermediate portion of the rotary shaft through a cylindrical minute gap. The tip-side peripheral surface of the sealing member is shaped so as to increase the pressure of the minute gap with the rotation of the rotary shaft at least at a portion corresponding to the exhaust hole. Based on such a minute gap and the shape of the tip end side peripheral surface of the sealing member, the water pump of the present invention, based on the pressure increased in the portion corresponding to the exhaust hole, causes the fluid entering the minute gap to It has the function of pushing out from the exhaust hole.

As a more specific structure for giving such a function, for example, the following structures (1) to (4) can be considered. By providing a cylindrical portion on the outer peripheral edge portion of the sealing member fixed to the outer peripheral surface of the intermediate portion of the rotating shaft, and eccentric the outer peripheral surface of the cylindrical portion with respect to the outer peripheral surface of the rotating shaft and the inner peripheral surface of the housing Make the thickness of the minute gaps uneven in the circumferential direction. Then, due to the wedge action generated between the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the housing as the rotary shaft rotates, the pressure in the minute gap is increased. A cylindrical portion is provided on the outer peripheral edge of the sealing member fixed to the outer peripheral surface of the intermediate portion of the rotating shaft, and the outer diameters of the outer peripheral surface of the cylindrical portion at a plurality of positions in the circumferential direction are gradually increased in the circumferential direction. As a result, the thickness of the minute gap is made non-uniform in the circumferential direction. Then, the pressure in the minute gap is increased by the wedge action generated at a plurality of circumferential positions between the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the housing as the rotary shaft rotates. The tip end side peripheral surface of the sealing member whose base end is fixed to the intermediate portion outer peripheral surface of the rotating shaft or the intermediate portion inner peripheral surface of the housing, and the intermediate portion inner peripheral surface of the housing or the intermediate portion outer peripheral surface of the rotating shaft. On at least one peripheral surface of the side peripheral surface and the peripheral surface facing each other, a groove or a ridge is formed which guides a fluid to the central portion in the width direction of the at least one peripheral surface as the rotary shaft rotates. As a result, the pressure in the central portion in the width direction of the one peripheral surface is increased, and the central portion in the width direction is conducted to the exhaust hole.

The water pump according to the second aspect of the present invention is, like the water pump described in Japanese Utility Model Laid-Open No. 5-19524, a housing having a cylindrical inner peripheral surface and not rotating, and an inner side of the housing. A rotating shaft supported via a bearing, and an impeller fixed to a portion projecting from an inner end opening of the housing at an inner end portion of the rotating shaft,
A sealing device provided between an inner peripheral surface of an inner end portion of the housing and an outer peripheral surface of an intermediate portion of the rotating shaft to close a space between the both peripheral surfaces; and an inner peripheral surface of the housing in a part of the housing. An atmosphere communication hole formed so as to penetrate the outer peripheral surface, an exhaust passage formed at the center of the rotating shaft and having one end open to the atmosphere, and a branch from this exhaust passage, the end of which is rotated as described above. A branch passage opened in a part of the outer peripheral surface of the shaft.

Particularly, in the water pump according to the second aspect, a part of the outer peripheral surface of the rotary shaft and the inner peripheral surface of the member fixed to the housing face each other with a cylindrical minute gap therebetween. doing. At least one of the two peripheral surfaces is shaped to increase the pressure around the rotary shaft at the end opening of the branch passage as the rotary shaft rotates. Based on such a minute gap and the shape of the peripheral surface, the water pump of the present invention allows the fluid that has entered the inner portion of the sealing device to flow into the branch passage and It has a function of pushing out through the exhaust passage.

As a more specific structure for giving such a function, for example, the following structure can be considered. In order to form the sealing device, a minute gap is formed between the inner peripheral surface of the cylindrical portion formed on a part of the member fixed to the housing and the outer peripheral surface of the rotary shaft, and these inner peripheral surfaces are formed. At least one of the outer circumferential surface and the outer circumferential surface guides the fluid to the central portion of the minute gap as the rotary shaft rotates.
Form a herringbone-shaped groove or ridge. Then, the end portion of the branch passage is opened to the central portion of the minute gap. In order to form the sealing device, a minute gap is formed between the inner peripheral surface of the cylindrical portion formed on a part of the member fixed to the housing and the outer peripheral surface of the rotary shaft, and these inner peripheral surfaces are formed. At least one of the outer circumferential surface and the outer circumferential surface is provided with a groove or ridge inclined in one direction for guiding the fluid to the inner side of the sealing device as the rotary shaft rotates. Then, the end of the branch passage is opened to the inner side of the sealing device.

[0019]

In the water pump of the present invention constructed as described above, the pressure of the fluid that leaks from the sealing device and enters the minute gap causes the exhaust hole or the end portion of the branch passage to follow the rotation of the rotating shaft. Raise at the portion corresponding to the opening. Therefore, this fluid is efficiently pushed out from the exhaust hole or the branch passage due to the increased pressure. As a result, it is possible to sufficiently effectively prevent the fluid from entering the bearing portion for supporting the rotating shaft.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 show a first example of an embodiment of the present invention corresponding to the above among the embodiments of the invention described in claim 1. The feature of the present invention is that the fluid such as water vapor leaking from the mechanical seal 9 which is the sealing device is efficiently discharged through the exhaust hole 27 to prevent the water vapor and the like from entering the bearing 4. The structure and operation of the other parts are the same as those of the above-described conventional art, and therefore, duplicate description will be omitted or simplified, and the characteristic part of the present invention will be mainly described below.

A cylindrical portion 29 is provided on the outer peripheral edge of a ring-shaped sealing member 28 fixed to the outer peripheral surface of the intermediate portion of the rotary shaft 3. By making the outer peripheral surface of the cylindrical portion 29 close to the inner peripheral surface of the intermediate portion of the housing 1, a cylindrical minute gap 30 is formed between the outer peripheral surface and the inner peripheral surface.
The sealing member 28 is fixed to the rotary shaft 3 by externally fitting the fitting cylinder portion 31 formed on the inner peripheral edge portion thereof to the rotary shaft 3. The outer peripheral surface of the cylindrical portion 29 is eccentric with respect to the inner peripheral surface of the fitting cylindrical portion 31 and the inner peripheral surface of the housing 1. Therefore, the thickness dimension of the minute gap 30 gradually changes in the circumferential direction. In the illustrated state, the thickness of the minute gap 30 is the narrowest at the lower end,
Widest at the top. However, the wide and narrow positions of this thickness dimension move in the circumferential direction as the rotary shaft 3 rotates.

On the other hand, an exhaust hole 27 for exhausting water vapor and the like leaking from the mechanical seal 9 is formed at the bottom of the housing 1. Further, a little from the bottom of the housing 1 and slightly forward of the direction of rotation of the sealing member 28 (in the case where the sealing member 28 rotates clockwise as shown by an arrow α in FIG. 2). The intake hole 26 is formed at a position displaced to the upper left of the exhaust hole 27). Similarly to the inner end opening of the exhaust hole 27, the inner end opening of the intake hole 26 faces the center portion in the width direction (the left-right direction in FIG. 1) of the minute gap 30.

Further, in the illustrated example, as shown in FIG. 3, a herringbone-shaped concave groove 32 is formed on the outer peripheral surface of the cylindrical portion 29.
A plurality of 32 are provided intermittently in the circumferential direction.
These concave grooves 32, 32 allow water vapor and the like in the minute gap 30 to be generated in the minute gap 3 as the sealing member 28 rotates.
It is formed in the direction of scraping to the center of the width direction of 0. More specifically, a direction toward the rear in the rotation direction of the sealing member 28 toward the widthwise central portion of the cylindrical portion 29 (the surface shown in FIG. 3 is rotated downward as indicated by an arrow β with rotation). In the case of displacing from above to the above, the central portion in the width direction is inclined downward).

In the case of the water pump of the present invention configured as described above, the water vapor and the like leaking from the mechanical seal 9 are effectively discharged from the exhaust hole 27 into the atmosphere. That is, the water vapor or the like leaking from the mechanical seal 9 enters the minute gap 30 between the inner peripheral surface of the intermediate portion of the housing 1 and the outer peripheral surface of the cylindrical portion 29. When the rotary shaft 3 rotates, the minute gap 30 behaves like a whirling motion in which the portion having the smallest thickness dimension rotates.
In the illustrated example, the outside air sucked from the intake hole 26 is rotated by a little over 300 degrees, and then the exhaust hole 27 is rotated.
Discharge more into the atmosphere. The water vapor and the like leaking from the mechanical seal 9 and entering the minute gap 30 are discharged into the atmosphere through the exhaust hole 27 together with this air.
Since the flow rate of water vapor or the like discharged from the exhaust hole 27 is limited as described above, no annoying noise is generated in the exhaust hole 27 portion. The position where the intake hole 26 is formed is not necessarily limited to the illustrated position.
The point is that it may be a part that can take in the air for discharging from the exhaust hole 27 together with the water vapor and the like.

The exhaust hole 2 is formed in a part of the minute gap 30.
Since the thickness dimension of the part facing 7 is small,
The pressure of the mixed fluid of air and water vapor existing in the minute gap 30 increases due to the wedge action toward the exhaust hole 27. Therefore, the mixed fluid is efficiently pushed out from the exhaust hole 27 based on the increased pressure. In particular, in the illustrated example, the concave grooves 32, 32 formed on the outer peripheral surface of the cylindrical portion 29 scrape the fluid in the minute gap 30 toward the central portion in the width direction of the minute gap 30, and further the minute gap 30. The fluid existing in the vicinity of the
Performs the function of sucking in 0. Therefore, it is extremely efficient to collect the water vapor and the like leaking from the mechanical seal 9 in the minute gap 30 and further discharge it through the exhaust hole 27. As a result, it is possible to sufficiently effectively prevent the fluid such as the water vapor from entering the bearing 4 portion for supporting the rotating shaft 3.

In the case of the first example, since the cylindrical portion 29 forming the sealing member 28 is eccentric with respect to the rotary shaft 3, rotation imbalance occurs as it is. However, since the diameter of the cylindrical portion 29 is small and the amount of eccentricity is limited, it is almost unnecessary to consider the occurrence of vibration due to this rotational imbalance. If a minute vibration is generated and cannot be ignored, the rotational imbalance is increased by increasing the thickness of a portion of the cylindrical portion 29 having a small diameter and increasing the weight of the portion. To eliminate.

Next, FIG. 4 shows a second example of the embodiment of the present invention, which corresponds to the above-described embodiment of the invention described in claim 1. In the case of this example, a cylindrical portion 33 (which is substantially cylindrical but is strictly non-cylindrical) is provided on the outer peripheral edge of the sealing member 28a that is externally fitted and fixed to the intermediate portion of the rotary shaft 3. There is. Unlike the case of the first example described above, the center of the cylindrical portion 33 and the center of the rotating shaft 3 are aligned.

However, in the case of this example, the outer diameter of the outer peripheral surface of the tubular portion 33 at a plurality of locations in the circumferential direction (three locations in the illustrated example) is set by forming the tubular portion 33 into a generally knot shape. Is gradually increased in the circumferential direction. Also in the case of this example, the outer peripheral surface of the cylindrical portion 33 is the inner peripheral surface of the intermediate portion of the housing 1,
They are opposed to each other via the minute gap 30a. However, due to the change in the outer diameter of the tubular portion 33, the thickness of the minute gap 30a is not uniform in the circumferential direction. Specifically, the thickness dimension of the minute gap 30a is 3 in the circumferential direction.
It becomes the widest at the location, and becomes gradually narrower toward both sides in the circumferential direction. Also in the case of this example, the intake hole 26 and the exhaust hole 27 are formed at the same positions as in the above-described first example.

In the case of this example constructed in this way, it occurs at a plurality of circumferential positions between the outer peripheral surface of the cylindrical portion 33 and the inner peripheral surface of the housing 1 as the rotary shaft 3 rotates. Due to the wedge action, the pressure in the minute gap 30a is increased, and water vapor or the like is discharged from the exhaust hole 27 together with the air sucked from the intake hole 26. Other configurations and operations are similar to those of the first example described above.

Next, FIGS. 5 to 7 correspond to those of the embodiment of the invention described in claim 1 as described above.
13 shows a third example of the embodiment of the present invention. In the case of this example, the exhaust hole 27 is formed at the bottom of the housing 1 as in the first example and the second example described above, but the intake hole 26 is provided at the top of the housing 1. There is. or,
The inner peripheral surface side opening of the intake hole 26 is displaced in the axial direction (left and right direction in FIG. 5) toward the bearing 4 side with respect to the inner peripheral surface side opening of the exhaust hole 27. A thick-walled ring-shaped sealing member 28b is internally fitted and fixed to the inner peripheral surface of the intermediate portion of the housing 1 so as to cover the inner peripheral surface side opening of the exhaust hole 27.

The inner peripheral surface, which is the peripheral surface on the front end side of the sealing member 28b, faces the outer peripheral surface of the intermediate portion of the rotary shaft 3 with a minute gap 30b. Further, a plurality of herringbone-shaped concave grooves 34, 34 are formed on the inner peripheral surface of the sealing member 28b.
It is provided intermittently in the circumferential direction. Each of these grooves 3
4, 34 are formed in a direction in which the fluid in the minute gap 30b is scraped toward the central portion in the width direction of the minute gap 30b as the rotary shaft 3 rotates. More specifically, as it goes to the center of the sealing member 28b in the width direction (horizontal direction in FIG. 5), the direction toward the front in the rotation direction of the rotation shaft 3 (the rotation shaft 3 facing the surface shown in FIG. 7). When the outer peripheral surface of the is displaced from the upper side to the lower side as indicated by an arrow γ, the outer peripheral surface is inclined toward the center in the width direction).

Further, in the illustrated example, the sealing member 28b is used.
An annular groove 35 is formed in the central portion of the inner peripheral surface in the width direction over the entire circumference of the inner peripheral surface. And this annular groove 3
5 and the exhaust hole 27 are electrically connected. Therefore, in the illustrated example, a wide outer peripheral annular groove 36 is formed on the outer peripheral surface of the sealing member 28b, and the inner peripheral surface side opening of the exhaust hole 27 is formed in the outer peripheral annular groove 36. They are facing each other. Then, the outer peripheral annular groove 36 and the annular groove 35,
The communication holes 37 communicate with each other.

In the case of this example configured as described above, the water vapor leaking from the mechanical seal 9 is prevented from leaking into the annular groove 3.
5, exhaust hole 2 through communication hole 37 and outer circumferential annular groove 36
7, and is effectively discharged toward the atmosphere from the exhaust hole 27. That is, the water vapor and the like leaking from the mechanical seal 9 and the outer peripheral surface of the intermediate portion of the rotary shaft 3 and the sealing member 28.
It enters into the minute gap 30b between the inner peripheral surface of b. The fluid existing in the minute gap 30b due to the rotation of the rotary shaft 3 has concave grooves 34, 34 formed on the inner peripheral surface of the sealing member 28b.
By this, it is scraped to the central portion in the width direction of the minute gap 30b. As a result, the pressure in the central portion in the width direction of the minute gap 30b rises, and the fluid scraped to the central portion is
The gas is discharged from the exhaust hole 27 through the annular groove 35, the communication hole 37, and the outer peripheral annular groove 36.

Further, by drawing the fluid in the minute gap 30b toward the center of the minute gap 30b, the pressure at both ends of the minute gap 30b in the width direction is reduced. As a result,
Fluids such as outside air and water vapor existing near the minute gap 30b are sucked into the minute gap 30b. Then, the fluid sucked into the minute gaps 30b is discharged into the atmosphere through the exhaust holes 27 through the above-described path. Other than that, the configuration and the operation are similar to those of the first example described above.

In the illustrated example, the grooves 34, 34 for scraping the fluid in the minute gap 30b to the center of the minute gap 30b in the width direction are formed on the inner peripheral surface of the sealing member 28b. The concave grooves 34, 34 can also be formed on the outer peripheral surface of the rotary shaft 3. Further, the annular groove 35 crossing the central portions of the grooves 34, 34 can be omitted. Further, if the communication hole 37 and the exhaust hole 27 are directly aligned, the outer peripheral annular groove 36 can be omitted. Further, the sealing member 28b is externally fitted and fixed to the outer peripheral surface of the intermediate portion of the rotary shaft 3, and the sealing member 28b
A minute gap 30b may be provided between the outer peripheral surface of b and the inner peripheral surface of the intermediate portion of the housing 1. In this case, the exhaust hole 27
The opening on the inner peripheral side of is directly opposed to the minute gap 30b. Further, instead of the concave grooves 34, 34, a ridge having the same shape can be formed.

Next, FIGS. 8 to 9 show a fourth example of the embodiment of the present invention, which corresponds to the above-mentioned embodiment among the embodiments of the present invention described in claim 2. In the case of this example, the atmosphere communication hole 38 is formed in a part of the housing 1 in a state where the inner peripheral surface and the outer peripheral surface of the housing 1 are penetrated. Further, an exhaust passage 39 is formed at the center of the rotary shaft 3,
One end (the left end in FIG. 8) of this exhaust passage 39 is opened to the atmosphere. Further, at the portion near the other end (close to the right end in FIG. 8) of the exhaust passage 39, the guide cylinder portion 16 of the support cylinder 14 constituting the mechanical seal 9 faces the inner peripheral surface of the central portion in the axial direction (the lateral direction in FIG. 8). A branch passage 40 is formed in the portion to be formed. Further, a cylindrical minute gap 41 is formed between the inner peripheral surface of the guide cylinder portion 16 and the outer peripheral surface of the rotary shaft 3, which corresponds to the cylindrical portion described in the above portion.

On the outer peripheral surface of the intermediate portion of the rotary shaft 3,
As shown in FIG. 9, in a portion facing the minute gap 41,
The herringbone-shaped concave grooves 42, 42 are formed.
Incidentally, FIG. 9A shows the concave grooves 42, 42 independent from each other, and FIG. 9B shows the central portions of the concave grooves 42, 42 connected by an annular concave groove 43. The opening of the branch passage 40 faces the central portions of the concave grooves 42, 42.

In the case of this example configured as described above, the water vapor and the like leaking from the mechanical seal 9 and entering the minute gap 41 are discharged from the atmosphere communicating hole 38 to the housing 1.
Together with the air sucked therein, the grooves 42, 42 formed on the outer peripheral surface of the rotary shaft 3 scrape the air into the central portion of the minute gap 41 in the width direction. As a result, this minute gap 41
The pressure in the central portion in the width direction (left and right direction in FIG. 8) of the fluid increases, and the fluid raked to the central portion causes the branch passage 40,
It is discharged through the exhaust passage 39. The basic operation is similar to that of the above-described third example except that the discharge route is slightly different. Similar to the case of the third example, it is possible to form a ridge having the same shape instead of the concave grooves 42, 42.

The concave grooves 42, 42 (or ridges) for increasing the pressure in the widthwise central portion of the minute gap 41 are formed on the outer peripheral surface of the intermediate portion of the rotary shaft 3 as in the fourth example. In addition to
As in the fifth example shown in FIG. 10, it may be formed on the inner peripheral surface of the guide tube portion 16 that constitutes the support tube 14. Furthermore,
Grooves 42, 42 (or ridges) are formed on both the outer peripheral surface of the intermediate portion of the rotary shaft 3 and the inner peripheral surface of the guide tube portion 16, or the concave grooves 42, 42 are formed on one peripheral surface. It is also possible to form ridges on the other peripheral surface.

Next, FIG. 11 shows a sixth example of the embodiment of the present invention, which corresponds to the above-mentioned among the embodiments of the present invention described in claim 2. In the case of this example, in the portion facing the minute gap 41 on the outer peripheral surface of the intermediate portion of the rotary shaft 3,
As the rotary shaft 3 rotates, the fluid is guided to the inner side of the mechanical seal 9 (on the side where the sliding contact portion between the rotary sliding surface 13 and the fixed sliding surface 22 exists, the right side in FIG. 11). Concave grooves 44, 44 that are inclined in one direction are formed. Then, the end of the branch passage 40 is opened to the inner side of the mechanical seal 9.

In the case of this example having such a configuration, the water vapor and the like leaking from the mechanical seal 9 and entering the minute gap 41 are connected to the atmosphere 38 (see FIG. 8; omitted in FIG. 11). With the air sucked into the housing 1 from the inside, the inside of the minute gap 41 is sent to the inner side of the mechanical seal 9 by the concave grooves 44 formed in the outer peripheral surface of the rotary shaft 3. As a result, the pressure at the back side portion rises, and the fluid pushed into the back side portion is discharged through the branch passage 40 and the exhaust passage 39. Also in the case of this example, it is possible to form a ridge having the same shape instead of the concave grooves 44, 44.

The recessed grooves 44, 44 (or ridges) for increasing the pressure in the inner portion of the mechanical seal 9 are
In addition to being formed on the outer peripheral surface of the intermediate portion of the rotary shaft 3 as in the sixth example, as in the seventh example shown in FIG. 12, it is formed on the inner peripheral surface of the guide tube portion 16 constituting the support tube 14. You can also Further, concave grooves 44, 44 (or ridges) are formed on both the outer peripheral surface of the intermediate portion of the rotary shaft 3 and the inner peripheral surface of the guide tube portion 16, or the concave groove 44 is formed on one peripheral surface. 44 may be formed on the other peripheral surface, respectively.

[0043]

Since the water pump of the present invention is constructed and operates as described above, it is possible to efficiently discharge the fluid such as steam leaking from the sealing device such as the mechanical seal to the atmosphere. As a result, it is possible to more reliably prevent the fluid from reaching the bearing for supporting the rotary shaft with respect to the housing, and to contribute to further improvement in the durability of the bearing. Also, the noise during driving does not increase. Furthermore, since it is not necessary to use parts with complicated shapes,
The production cost does not increase.

[Brief description of the drawings]

FIG. 1 is a sectional view of a water pump showing a first example of an embodiment of the present invention.

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

FIG. 3 is a side view showing an example of a dynamic pressure groove formed on the outer peripheral surface of the sealing member.

FIG. 4 is a view similar to FIG. 2, showing a second example of the embodiment of the present invention;

FIG. 5 is a sectional view of the water pump showing the third example.

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

FIG. 7 is a sectional view taken along line CC of FIG. 6, showing only the sealing member.
Sectional view.

FIG. 8 is a cross-sectional view of a water pump showing a fourth example of the embodiment of the present invention.

FIG. 9 is a side view showing two examples of dynamic pressure grooves formed on the outer peripheral surface of the rotary shaft.

FIG. 10 is a side view showing two examples of dynamic pressure grooves formed on the inner peripheral surface of the guide tube portion in the fifth example of the embodiment of the present invention.

FIG. 11 is a sectional view showing the sixth example, which corresponds to the portion D in FIG. 8;

FIG. 12 is a sectional view showing the seventh example, similar to FIG. 11.

FIG. 13 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 Annular Recessed 11 Seat Ring 12 Buffer Material 13 Rotation Side Sliding Surface 14 Support Tube 15 Support Plate Section 16 Guide Tube Section 17 Fit Joint cylinder 18 Locking collar 19 Driven ring 20 Bellows 21 Compression coil spring 22 Fixed side sliding surface 23 Locking collar 24 Base 25 Sealing member 26 Intake hole 27 Exhaust hole 28, 28a, 28b Sealing member 29 Cylindrical Part 30, 30a, 30b Micro gap 31 Fitting cylinder part 32 Recessed groove 33 Cylindrical part 34 Recessed groove 35 Annular recessed groove 36 Outer peripheral side annular recessed groove 37 Communication hole 38 Atmosphere communication hole 39 Exhaust passage 40 Branch passage 41 Micro gap 42 Concave Groove 43 Annular groove 44 Groove

Claims (2)

[Claims] 1. A housing having a cylindrical inner peripheral surface that does not rotate, a rotating shaft supported inside the housing via bearings, and an inner end opening of the housing at an inner end portion of the rotating shaft. An impeller fixed to a portion projecting from the housing, a sealing device provided between an inner peripheral surface of an inner end portion of the housing and an outer peripheral surface of an intermediate portion of the rotating shaft to close a space between the peripheral surfaces, and the housing. An exhaust hole which is formed in a part of the housing so as to penetrate the inner peripheral surface and the outer peripheral surface of the housing and has an inner peripheral surface side opening located between the sealing device and the bearing; and an exhaust hole facing the exhaust hole. In the portion, the outer peripheral surface of the intermediate portion of the rotary shaft or the inner peripheral surface of the intermediate portion of the housing is provided with a sealing member having a proximal end portion fixed in a state of diametrically projecting from the peripheral surface. For water pump whose shaft can be driven to rotate In the above, the peripheral surface on the front end side of the sealing member is a peripheral surface different from the peripheral surface on which the sealing member is fixed,
It faces the inner peripheral surface of the intermediate portion of the housing or the outer peripheral surface of the intermediate portion of the rotating shaft through a cylindrical minute gap, and the peripheral surface at the tip end side of the sealing member is rotated with the rotation of the rotating shaft. It is shaped so as to increase the pressure in the minute gap at least in the portion corresponding to the exhaust hole, and has a function of pushing out the fluid entering the minute gap from the exhaust hole based on the pressure increased in this portion. Water pump characterized by. 2. A housing which has a cylindrical inner peripheral surface and does not rotate, a rotary shaft supported inside the housing via a bearing, and an inner end opening of the housing at the inner end of the rotary shaft. An impeller fixed to a portion projecting from the housing, a sealing device provided between an inner peripheral surface of an inner end portion of the housing and an outer peripheral surface of an intermediate portion of the rotating shaft to close a space between the peripheral surfaces, and the housing. An atmosphere communication hole formed in a part of the housing so as to penetrate the inner peripheral surface and the outer peripheral surface of the housing, an exhaust passage formed in the center of the rotary shaft and having one end open to the atmosphere, and the exhaust passage In a water pump having a branch passage that branches from the outer peripheral surface of the rotating shaft and is opened at a part of the outer peripheral surface of the rotating shaft, the water pump is fixed to a part of the outer peripheral surface of the rotating shaft and the housing. A small cylindrical gap is formed between the inner peripheral surface of the member and At least one of the two peripheral surfaces faces each other and has a shape that increases the pressure around the rotary shaft at the end opening portion of the branch passage as the rotary shaft rotates. The water pump is characterized in that it has a function of pushing out the fluid, which has entered the inner portion of the sealing device, through the branch passage and the exhaust passage based on the pressure increased in this portion.