JP5197722B2 - Water pump - Google Patents

Description

  The present invention relates to a water pump that is used, for example, to supply cooling water for cooling an engine to the inside of the engine.

  As this type of conventional water pump, one described in Patent Document 1 below is known.

  In brief, a pump shaft formed integrally with a pulley by press molding inside a pump housing is rotatably supported by a ball bearing, and an impeller is fixed to a tip portion of the pump shaft.

  The ball bearing has an outer ring fixed to the inner peripheral part of the pulley, and an inner ring fixed to the outer peripheral surface of the cylindrical part of the pump housing.

  Further, a mechanical seal is provided between the pump shaft and the pump housing to prevent leakage of cooling water from the pump chamber in which the impeller is rotatably accommodated in the ball bearing direction.

Japanese Patent Laying-Open No. 2004-84610 (FIG. 1)

  However, in the water pump described in the publication, it is difficult to completely prevent the leakage of cooling water from the pump chamber with the mechanical seal from the structural point of view. For this reason, the cooling water leaking from the mechanical seal may enter the inside of the ball bearing along the outer peripheral surface of the pump shaft. As a result, the durability of the ball bearing decreases due to rusting or the like.

  The present invention has been devised in view of the actual situation of the conventional water pump, and it does not leak from the mechanical seal and is transmitted to the bearing through the pump shaft without being transmitted to the bearing. A water pump is provided.

  In the first aspect of the invention, in particular, the pump shaft is provided with a small-diameter shaft portion having a smaller diameter than an outer peripheral surface of a portion where the mechanical seal is disposed at a portion between the mechanical seal and the flange wall. A step portion is formed between the portion extending in the axial direction from the outer peripheral surface of the portion where the seal is disposed and the small-diameter shaft portion.

  According to a second aspect of the present invention, the stepped portion is formed on a vertical surface perpendicular to the central axis of the pump shaft, or has an acute angle so as to approach the mechanical seal from the outer peripheral side to the inner peripheral side. It is characterized by being formed into an inclined surface.

  According to a third aspect of the present invention, a drain chamber capable of storing a predetermined volume of cooling water and a drain hole that guides water dripped from the stepped portion to the drain chamber are provided below the stepped portion in the direction of gravity. It is characterized by having.

  According to this invention, the cooling water leaking from the mechanical seal can be effectively prevented from moving in the bearing direction by the stepped portion.

It is a longitudinal section of a 1st embodiment of a water pump concerning the present invention. It is a disassembled perspective view of the water pump in this embodiment. It is a principal part side view of the pump shaft provided to 2nd Embodiment. It is principal part side sectional drawing of the pump shaft provided to 3rd Embodiment. It is principal part side sectional drawing of the pump shaft provided to 4th Embodiment. It is a principal part side view of the pump shaft provided to 5th Embodiment. It is a principal part side view of the pump shaft provided to 6th Embodiment. It is a principal part side view of the pump shaft provided to 7th Embodiment. It is a principal part side view of the pump shaft provided to 8th Embodiment.

Hereinafter, each embodiment of the water pump according to the present invention will be described with reference to the drawings. [First Embodiment]
1 and 2 show a first embodiment of a water pump according to the present invention. The water pump 1 is applied to a cooling device for circulating an antifreeze liquid (ethylene glycol) as cooling water between a radiator of an automobile and an engine. Has been.

  The water pump 1 is directly attached to a side of a cylinder block (not shown) of the engine by bolting or the like, and has a pump housing 2 in which a pump chamber 3 is formed in a front end on the cylinder block side, and an outer periphery of the pump housing 2 On the side, a pulley 4 rotatably supported by a single ball bearing 5, a pump shaft 6 inserted and disposed inside the pump housing 2 and having one end 6 a fixed to the pulley 4, and the pump shaft The impeller 7 fixed to the other end 6b of the pump 6 and rotatably accommodated in the pump chamber 3, and interposed between the pump housing 2 and the pump shaft 6, the pump chamber 3 and the ball It is mainly composed of a mechanical seal 8 that seals between the bearing 5.

  The pump housing 2 is integrally formed of, for example, an aluminum alloy material, the housing body 9 on the pump chamber 3 side is formed in a deformed annular shape, and a cylindrical shape with a step diameter is formed on the rear end side of the housing body 9. The part 10 has integrally.

  The housing body 9 is formed with a flat annular mounting surface 9a at the front end that abuts against a flat portion on the side of the cylinder block, and a mounting bolt that is screwed and fixed to the cylinder block is inserted through the outer periphery. A plurality of boss portions 9c constituting the bolt holes 9b are provided.

  Further, a discharge port 9d for discharging cooling water flowing into the pump chamber 3 from a radiator-side suction port (not shown) into the water jacket in the cylinder block as the impeller 7 rotates is provided inside the housing body 9. Is formed.

  As shown in FIGS. 1 and 2, the cylindrical portion 10 includes a large-diameter portion 10a on the pump chamber 3 side, a medium-diameter portion 10b extending from the large-diameter portion 10a in the ball bearing 5 direction, A small-diameter portion 10c extending from the middle-diameter portion 10b toward the one end portion 6a of the pump shaft 6 is formed, and thus a hollow portion 10d having a stepped diameter is formed inside.

  In the middle diameter portion 1b, a drain hole 11 through which water droplets of cooling water leaked from the mechanical seal 8 flow down is formed in the vertical direction, and the drain hole 11 is formed below the drain hole 11. A drain chamber 12 for collecting and storing water droplets dripped from the drain hole 11 is formed across the inside of the large diameter portion 10a. The drain chamber 12 is liquid-tightly sealed at its lower end opening with a drain cap 13.

  In addition, an air opening hole 14 is formed on the upper side of the middle diameter portion 10b in the gravity direction to discharge water vapor of cooling water leaked from the mechanical seal 8 or stored in the drain chamber 12 or the like. Has been. Furthermore, an annular space chamber 15 is formed between the inner diameter portion 10 b and the pump shaft 6, and the annular space chamber 15 includes the drain hole 11 and the atmosphere opening hole 14. Is communicated in the vertical direction. In addition, a cylindrical bulging portion 10f that forms an air communication hole 18 that communicates the air opening hole 14 and the atmosphere is integrally formed on the outer periphery of the medium diameter portion 10b.

  As shown in FIGS. 1 and 2, the pulley 4 is integrally formed in a disk shape by press-molding a metal plate material, and a central cylindrical shape into which one end portion 6a of the pump shaft 6 is press-fitted and fixed. Fixed portion 4a, a disc-shaped flange wall 4b extending from the axial end edge of the fixed portion 4a in the radial direction of the pump shaft 6, and the outer peripheral edge of the flange wall 4b in the axial direction of the pump shaft 6 A bent large-diameter cylindrical portion 4c, a large-diameter second flange wall 4d bent in the radial direction of the pump shaft 6 from the axial end edge of the cylindrical portion 4c, and the second The belt mounting portion 4e is formed in a folded shape from the outer peripheral edge of the flange 4d.

  The fixing portion 4a has an air vent hole 4e penetratingly formed at the tip portion thereof to ensure smooth press-fitting of the pump shaft 6, and a cover member 17 described later is press-fitted and fixed to the outer periphery.

  As shown in FIG. 2, the flange wall 4b has a plurality of through holes 16 formed at substantially equal positions in the circumferential direction at substantially the center position in the radial direction. Each through-hole 16 has a role as a work hole for inserting a press-fitting jig (not shown) when the inner ring 5a of the ball bearing 5 is press-fitted into the outer periphery of the small-diameter portion 10c of the cylindrical portion 10. In addition, it also has a role of discharging the water vapor that has evaporated from the drain chamber 12 and the like and has reached the inside of the small diameter portion 10c to the outside. Therefore, each through hole 16 is set to a position and a size necessary for the respective formation positions and inner diameters to fulfill the respective roles.

  The cylindrical portion 4c is configured such that the outer ring 5b of the ball bearing 5 is press-fitted and fixed to the inner peripheral surface, and therefore the axial length thereof is slightly larger than the axial length of the outer ring 5b. The inner diameter of the outer ring 5b is slightly smaller than the outer diameter of the outer ring 5b.

  The second flange wall 4d is formed in a bulging shape in the direction of the impeller 7, thereby ensuring rigidity.

  The belt mounting portion 4e is configured such that a transmission belt wound around a driving pulley fixed to a distal end portion of a crankshaft (not shown) is wound around an outer periphery formed in a wavy tooth shape to transmit a rotational force. It has become.

  The cover member 17 is formed in a substantially bowl shape by a thin metal plate, and is disposed so as to cover the flange wall 4b of the pulley 4 and the front surface of the cylindrical portion 4c and the second flange wall 4d. Further, the central cylindrical portion 17a is press-fitted and fixed to the outer periphery of the fixed portion 4a, and the inner surface of the disc portion 17b formed along the radial direction from the axial end edge of the cylindrical portion 17a is the flange. The entire facing surface of the wall 4b is covered with a slight gap S between the facing surface. Further, the large-diameter portion 17c extending in the radial direction from the outer peripheral edge of the disc portion 17b is formed to be inclined in the direction of the second flange wall 4d, and the substantially vertical outer peripheral portion 17d is The inner circumferential surface of the belt mounting portion 4e, the clearance S3, and the opposing surface of the second flange wall 4d are opposed to each other with a slight annular clearance S1.

  Accordingly, the cover member 17 closes the front end opening of each through-hole 16 in the flange wall 4b to prevent entry of dust and the like from the outside, and evaporates from the drain chamber 12 and the like to open each through-hole 16. The water vapor that has passed is discharged to the outside through the gaps S, S1, and S3.

  The ball bearing 5 is a general one, and an inner ring 5a press-fitted into the small diameter part 10, an outer ring 5b press-fitted into the cylindrical part 4c, and a cage between the inner ring 5a and the outer ring 5b. And a plurality of balls 5c provided so as to roll freely.

  In the inner ring 5a, the maximum axial insertion position of the inner ring 5a is regulated by an annular protrusion 10e provided at the front end edge of the medium diameter part 10b of the cylindrical part 10, while the outer ring 5b is controlled by positioning of the inner ring 5a. Naturally, the axial position is set by press-fitting into the cylindrical portion 4c.

  An annular gap S2 is formed between the front edge of the ball bearing 5 and the flange wall 4b to guide the water vapor or the like toward the through holes 16.

  Bearing seals 19a and 19b made of a pair of annular rubber materials for preventing intrusion of dust and the like are provided inside the front and rear ends of the inner ring 5a and the outer ring 5b, respectively. Each of the bearing seals 19a and 19b has an outer peripheral portion fixed to each end portion in the axial direction of the outer ring 5b, while an inner peripheral portion is slidably formed on the inner ring 5a so as to seal the inside. It has become.

  Further, as shown in FIG. 2, a thin annular plate-shaped shielding plate 20 is sandwiched between the inner ring 5a and the annular protrusion 10e of the medium diameter portion 10b and fixed to the outer periphery of the small diameter portion 10c. ing. The shielding plate 20 is arranged so as to cover the rear end edge side of the ball bearing 5 so as to prevent dust from the outside from entering the ball bearing 5.

  As shown in FIGS. 1 and 2, the pump shaft 6 is substantially entirely formed of a metal material with a uniform outer diameter, and is annularly cut out at a substantially central position in the axial direction of the outer peripheral surface 6c. A small-diameter shaft portion 21 that is an annular groove is formed.

  That is, the small-diameter shaft portion 21 is provided between the mechanical seal 8 and the flange wall 4b, that is, at a position facing the annular space chamber 15, and one end surface on the mechanical seal 8 side is a step portion. The second step surface 23 is configured as a first step surface 22, and the other end surface opposite to the first step surface 22.

  The first and second step surfaces 22 and 23 are formed in a direction perpendicular to the axis of the pump shaft 6, and the outer peripheral edges 22 a and 23 a are connected to the drain hole 11 and the air release hole via the annular space chamber 15. 14 The small-diameter shaft portion 21 has an axial width, that is, a width W between the stepped surfaces 22 and 23 set to about 2 mm and a depth D set to about 1 mm. It is possible to set the width W to 2 mm or more and the depth D to 1 mm or more.

  The impeller 7 is integrally formed by press molding, and is a cylindrical press-fit fixing portion 7a that is press-fitted and fixed to the other end portion 6b of the pump shaft 6, and a radial direction from the axial end edge of the press-fit fixing portion 7a. It is comprised from the several blade | wing part 7b extended. An air vent hole 7c for smoothly press-fitting the pump shaft 6 is formed at the center position of the press-fit fixing portion 7a.

  The mechanical seal 8 is a general one, and is a cartridge portion 8a fixed to the inner peripheral surface of the medium diameter portion 10b of the tubular portion 10 and a sleeve supported by the outer peripheral surface 6c of the pump shaft 6. It comprises a portion 8b and a seal portion 8c which is provided between the inner peripheral side of the cartridge 8a and the outer peripheral side of the sleeve portion 8b and slides.

  Therefore, according to this embodiment, when the crankshaft of the engine is rotationally driven and the pulley 4 is rotationally driven, the impeller 7 is rotated via the pump shaft 6 to perform a pumping action, and cooling water is supplied. The engine is cooled by being pumped from the discharge port 9d to the water jacket of the engine.

  At this time, most of the cooling water in the pump chamber 3 having the high pressure is restricted from flowing into one end side of the pump shaft 6 by the mechanical seal 8, but a part of the cooling water is, for example, the mechanical seal 8. Leaks from the sliding seal portion 8 c and flows along the outer peripheral surface 6 c of the pump shaft 6 toward the one end portion 6 a. When the flowing cooling water reaches the first step surface 22, it is cut at the outer peripheral edge 22 a of the first step surface 22 with the action of the rotational centrifugal force of the pump shaft 6, and passes through the annular space chamber 15. It is dropped from the drain hole 11 into the drain chamber 12 and collected and stored here.

  That is, since the outer peripheral edge 22a of the first step surface 22 is formed perpendicular to the pump shaft 6, the cooling water that has traveled along the outer peripheral surface 6c is quickly cut and drain hole 11 is formed. And is dripped and stored in the drain chamber 12.

  Therefore, most of the leaked cooling water does not reach the second stepped surface 23 side along the outer peripheral surface of the small-diameter shaft portion 21 by the effective draining action of the first stepped surface 22.

  Further, even if the cooling water adhering to the outer peripheral surface of the small-diameter shaft portion 21 flows along the outer peripheral surface of the small-diameter shaft portion 21 in the direction of the one end portion 6a, the outer surface travels along the second step surface 23. It is cut by the peripheral edge 23 a and dropped into the drain chamber 12.

  The cooling water stored in the drain chamber 12 evaporates into water vapor, or most of the water vapor leaking from the mechanical seal 8 is connected to the atmosphere communication hole via the annular space chamber 15 and the air release hole 14. 18 is discharged to the outside.

  Further, this water vapor flows into the annular gap S2 from the annular space chamber 15 through the cylindrical passage 24 formed between the outer peripheral surface of the pump shaft 6 and the inner peripheral surface of the small diameter portion 10c of the cylindrical portion 10. In this case, the air then flows into the gap S through the through holes 16 and is further discharged from the annular gaps S1 and S3 to the outside through the space between the cover member 17 and the pulley 4.

  As described above, most of the cooling water leaking from the mechanical seal 8 and flowing into the small diameter shaft portion 21 through the outer peripheral surface 6 c of the pump shaft 6 is effectively cut off by the first step surface 22. Then, since the liquid drops from the drain hole 11 into the drain chamber 12, the inflow into the ball bearing 5 can be sufficiently suppressed.

  Moreover, even if it flows slightly along the outer peripheral surface of the small-diameter shaft portion 21 toward the one end portion 6 a, it is effectively cut at the outer peripheral edge 23 a of the second step surface 23 and is drained through the drain hole 11. Since the liquid drops into the ball 12, entry into the ball bearing 5 is sufficiently prevented.

  Furthermore, since the water vapor is also quickly discharged to the outside through the air opening hole 14, the annular gap S2, the through hole 16, and the gaps S, S1, and S3, the intrusion into the ball bearing 5 is suppressed. .

  Further, since the inside of the ball bearing 5 is sealed by the bearing seals 19a and 19b, it becomes possible to further prevent the intrusion of cooling water and water vapor into the ball bearing 5.

  Further, dust and the like from the outside can be prevented from entering the inside of the ball bearing 5 from the through holes 16 by the cover member 17, and the inside of the ball bearing 5 from the outside of the medium diameter portion 10 b by the shielding plate 20. Intrusion of dust etc. into the can also be prevented.

  As a result, the occurrence of rust inside the ball bearing 5 and the intrusion of dust inside the ball bearing 5 are suppressed, so that the durability of the ball bearing 5 can be improved.

Further, since the outer peripheral surface of the small diameter shaft portion 21 is formed in a simple cylindrical shape, it can be easily formed by grinding after the pump shaft 6 is formed.
[Second Embodiment]
3 to 9 show modified examples of the small-diameter shaft portion 21 of the pump shaft 6. In the second embodiment shown in FIG. 3, the small-diameter shaft portion 21 of the pump shaft 6 is extended to the one end portion 6a. Is. Therefore, only the first step surface 22 formed in the direction perpendicular to the axis exists and the second step surface does not exist, but the water that has traveled on the outer peripheral surface 6c can be effectively cut by the first step surface 22. become.

According to this embodiment, since the whole of the one end portion 6a side of the pump shaft 6 is formed with a small diameter, the pump shaft 6 can be reduced in weight in addition to the above-described effects.
[Third Embodiment]
In the third embodiment shown in FIG. 4, the small-diameter shaft portion 21 is extended to the one end portion 6a as in the second embodiment, and the first step surface 22 is a mechanical seal extending from the outer peripheral edge 22a to the inner peripheral edge. The outer peripheral edge 22a of the first step surface 22 is formed to have a sharp cross section with a taper shape that decreases in eight directions.

Therefore, according to this embodiment, the water that has flowed from the mechanical seal 8 side along the outer peripheral surface 6 c toward the small-diameter shaft portion 21 is reliably cut by the acute outer peripheral edge 22 a of the first step surface 22. For this reason, the draining action is further improved, and transmission to the outer peripheral surface of the small diameter shaft portion 21 can be sufficiently suppressed.
[Fourth Embodiment]
In the fourth embodiment shown in FIG. 5, the first step surface 22 is formed with an acute cross-sectional shape as in the third embodiment, while the second step surface 23 is the shaft of the pump shaft 6 as in the first embodiment. It is formed in a perpendicular direction.

Therefore, the first step surface 22 can obtain the same effect as that of the third embodiment, and the second step surface 23 can further cut the water that has slightly passed along the outer peripheral surface of the small-diameter shaft portion 21. become.
[Fifth Embodiment]
In the fifth embodiment shown in FIG. 6, the first step surface 22 is formed in the direction perpendicular to the axis of the pump shaft 6 as in the first and second embodiments, but the first step surface 23 extends from the inner periphery to the outer periphery. Toward the flange wall 4b, that is, a taper surface having an upward slope.

According to this embodiment, not only the effective draining action by the first step surface 22 is obtained, but also the second step surface 23 is formed on the upward tapered surface, but the draining action is reduced. The rigidity of the pump shaft 6 is increased and the occurrence of concentrated stress in the bending direction can be suppressed.
[Sixth Embodiment]
The sixth embodiment shown in FIG. 7 is basically the same as that of the first embodiment, but the outer diameter of the pump shaft 6 is temporarily tapered from the one end 6a side to the other end 6b side. Formed. Accordingly, the outer peripheral edge 22a of the first step surface 22 formed in the direction perpendicular to the axis is inevitably having a slightly acute cross section while the outer peripheral edge 23a of the second step surface 23 has a slightly obtuse cross section. ing.

Therefore, in this embodiment, the draining action at the outer peripheral edge 22a of the first step surface 22 is particularly good.
[Seventh Embodiment]
In the seventh embodiment shown in FIG. 8, the first and second step surfaces 22 and 23 are each formed in two steps. Also in this case, the draining action can be effectively performed by the two outer peripheral edges 22a and 22b of the first step surface 22, and the second step surface 23 can be drained by the two outer peripheral edges 23a and 23b. Become. And since each is formed in step shape, generation | occurrence | production of the concentrated stress of bending deformation can be suppressed.
[Eighth Embodiment]
In the eighth embodiment shown in FIG. 9, the structure is basically the same as that of the first embodiment, but an annular protrusion 25 is integrally formed at the axial center position of the small-diameter shaft 21. It is. The annular protrusion 25 is set to have the same outer diameter as the pump shaft 6, and both surfaces 25 a and 25 b are formed in the direction perpendicular to the axis of the pump shaft 6.

  Further, the first and second step surfaces 22 and 23 are formed in a direction perpendicular to the axis as the both surfaces 25a and 25b.

  Therefore, most of the water flowing in the direction of the one end portion 6a along the outer peripheral surface 6c of the pump shaft 6 is first cut at the outer peripheral edge 22a of the first step surface 22, but a part of the small diameter shaft portion 21 is partly cut. Even when it flows in the direction of the annular protrusion 25 along the outer peripheral surface of the annular protrusion 25, it is cut at the outer peripheral edge 25 c of the one end face 25 a of the annular protrusion 25 and dropped in the direction of the drain hole 11.

  Therefore, although it hardly flows in the direction of the second step surface 23 due to such double draining, even if it flows, the outer peripheral edge 25d of the other end surface 25b of the annular protrusion 25 and the outer peripheral edge 23a of the second step surface 23. Therefore, there is no flow in the direction of the one end 6a, that is, in the direction of the ball bearing 5.

  Further, since the strength of the small-diameter shaft portion 21 of the pump shaft 6 is increased by the annular protrusion 25, it is possible to sufficiently cope with bending deformation and torsional deformation.

  The present invention is not limited to the configuration of each of the embodiments described above. For example, the width W and the depth D of the small diameter shaft portion 21 can be further changed, and the first step surface 22 and the first step surface 22 can be changed. The taper angle with the two step surfaces 23 can also be changed.

  Further, the bearing is not limited to the ball bearing 5 and may be, for example, a plain bearing or a needle bearing.

  Furthermore, although the first step surface 22 is formed along the direction perpendicular to the axis of the pump shaft 6 in the first embodiment or the like, the angle of the surface is formed in a slight taper shape in an acute angle or obtuse angle direction. May be.

The technical ideas of the invention other than the claims ascertained from the embodiment will be described below.
[Claim a] In the water pump according to claim 1,
The water pump according to claim 1, wherein an outer peripheral surface of the small-diameter shaft portion is formed in a cylindrical shape.

According to this invention, since the outer peripheral surface of the small-diameter shaft portion is simply cylindrical, it can be easily formed by grinding after forming the pump shaft.
[Claim b] In the water pump according to claim 1,
The small-diameter shaft portion is partially provided on the pump shaft, and a second step portion is formed on the flange wall side.

According to this invention, even if the water that has moved to the flange wall side along the outer peripheral surface of the small-diameter shaft portion is cut by the outer peripheral edge of the second stepped portion, it is directed toward the flange wall direction, that is, in the bearing direction. Movement can be regulated effectively.
[Claim c] In the water pump according to claim b,
The second stepped portion is formed on a vertical surface perpendicular to the central axis of the pump shaft, or increases in diameter as it approaches the flange wall from the inner peripheral side to the outer peripheral side. A water pump characterized by being formed in an inclined shape.

According to this invention, since the second step portion is formed in an enlarged diameter, the strength of the pump shaft can be ensured.
[Claim d] In the water pump according to claim 3,
The water pump is characterized in that the drain chamber is open to the atmosphere.

The water stored in the drain chamber can be evaporated and discharged to the atmosphere.
(Claim e) In the water pump according to claim d,
An annular space portion is formed between the outer peripheral surface of the small-diameter shaft portion and the inner peripheral surface of the tubular portion, and the drain hole is formed below the annular space portion in the gravity direction of the tubular portion. On the other hand, an air opening hole is formed on the upper side in the direction of gravity.
[Claim f] In the water pump according to claim 1,
The pump shaft is formed in a tapered shape having a small diameter continuously from the flange wall side in the axial direction toward the impeller side, and the stepped portion is perpendicular to the central axis of the pump shaft. A water pump characterized by being formed on a surface.

According to the present invention, the cooling water that has traveled from the mechanical seal side along the tapered outer peripheral surface of the pump shaft is effective due to the sharp edge between the tapered outer peripheral surface and the outer peripheral edge of the vertical surface of the stepped portion. It is possible to cut into
[Claim g] In the water pump according to claim 1,
The pulley has a second flange wall extending outward from an end opposite to the flange wall of the cylindrical portion in the axial direction, and is folded back from the outer peripheral edge of the second flange wall in the axial direction of the flange wall. A water pump comprising a formed belt mounting portion.
(Claim h) In the water pump according to claim 1,
The water pump is characterized in that the pulley and the flange wall are integrally formed.
(Claim i) In the water pump according to claim h,
The water pump is characterized in that the pump shaft and the flange wall are formed separately, and one end of the pump shaft is fixed to the flange wall.
[Claim j] In the water pump according to claim 1,
A water pump, wherein a plurality of through holes are formed in the flange wall.

According to this invention, the bearing is fixed from the axial direction between the cylindrical portion and the cylindrical portion by a jig using the plurality of through holes, and the water vapor that has passed through the mechanical seal is exposed to the outside. It becomes possible to discharge.
(Claim k) In the water pump according to claim 1,
The water pump is characterized in that the step portion is formed in a plurality of steps.
(Claim 1) In the water pump according to claim k,
A water pump comprising a plurality of the small-diameter shaft portions.
[Claim m] In the water pump according to claim 1,
A water pump characterized in that a bearing seal is provided which is fixed to one side of the inner ring and the outer ring of the bearing and slides relative to the other side.

By this bearing seal, the intrusion of water or the like into the bearing can be regulated.
[Claim n] In the water pump according to claim 1,
The height of the said level | step-difference part is set to 1 mm or more, The water pump characterized by the above-mentioned.
[Claim o]
A pulley having a cylindrical portion on the inner peripheral side, rotated by transmission of power from the drive source,
A pump shaft fixed to the inner peripheral side of the cylindrical portion;
A flange wall that is bent in the direction of the pump shaft from the axial outer end edge of the cylindrical portion;
An impeller provided on the other axial end side of the pump shaft;
A pump housing having a cylindrical portion surrounding an outer peripheral side of the pump shaft;
A mechanical seal disposed between the inner peripheral side of the tubular portion and the outer peripheral surface of the pump shaft;
A bearing provided between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the cylindrical portion and rotatably supporting the pulley;
The pump shaft has a stepped portion that restricts movement of the adhering water that has traveled from the mechanical seal side along the outer peripheral surface toward the flange wall at a portion between the mechanical seal and the flange wall. A water pump characterized by that.
[Claim p]
A pump shaft provided with a pulley at one end and an impeller at the other end;
A pump housing surrounding an outer peripheral side of the pump shaft;
A bearing provided in the pump housing and rotatably supporting the pump shaft;
A mechanical seal that is fixed to the pump housing and the pump shaft and includes a seal portion that slides at a position closer to the impeller than the bearing in the axial direction of the pump shaft;
The water pump according to claim 1, wherein an annular groove that prevents transmission of adhering water in the bearing direction is formed in the middle of the outer peripheral surface from the mechanical seal to the bearing in the pump shaft.
[Claim q] In the water pump according to claim p,
The water pump according to claim 1, wherein the axial width of the annular groove is set to 2 mm or more.

DESCRIPTION OF SYMBOLS 1 ... Water pump 2 ... Pump housing 3 ... Pump chamber 4 ... Pulley 5 ... Ball bearing (bearing)
6 ... pump shaft 6a ... one end 6b ... other end 6c ... outer peripheral surface 7 ... impeller 8 ... mechanical seal 8c ... seal part 9 ... housing body 10 ... cylindrical part 10b ... medium diameter part 11 ... drain hole 12 ... drain chamber 14 ... Air opening hole 15 ... Annular space 16 ... Through hole 17 ... Cover member 18 ... Air communication hole 19a, 19b ... Bearing seal 20 ... Shielding plate 21 ... Small diameter shaft (annular groove)
22 ... First step surface (step portion)
22a ... outer peripheral edge 23 ... second step surface 23a ... outer peripheral edge 26 ... annular projection

Claims (3)

A pulley having a cylindrical portion on the inner peripheral side, rotated by transmission of power from the drive source,
A pump shaft fixed to the inner peripheral side of the cylindrical portion;
A flange wall that is bent in the direction of the pump shaft from the axial outer end edge of the cylindrical portion;
An impeller provided on the other axial end side of the pump shaft;
A pump housing having a cylindrical portion surrounding an outer peripheral side of the pump shaft;
A mechanical seal disposed between the inner peripheral side of the cylindrical portion and the outer peripheral surface of the pump shaft;
A bearing provided between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the cylindrical portion and rotatably supporting the pulley;
The pump shaft is provided with a small-diameter shaft portion having a smaller diameter than an outer peripheral surface of a portion where the mechanical seal is disposed at a portion between the mechanical seal and the flange wall, and an outer periphery of the portion where the mechanical seal is disposed. A water pump, wherein a step portion is formed between a portion extending in the axial direction from the surface and the small-diameter shaft portion. The water pump according to claim 1,
The step portion is formed on a vertical surface perpendicular to the central axis of the pump shaft, or is formed on a tapered surface that is inclined downward toward the mechanical seal from the outer peripheral side to the inner peripheral side. A water pump characterized by that. The water pump according to claim 1,
A water pump characterized in that a drain chamber capable of storing a predetermined volume of cooling water and a drain hole for guiding water dripped from the stepped portion to the drain chamber are provided below the stepped portion in the direction of gravity. .

Images