JP5732380B2 - 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, the drive shaft is rotatably supported inside the pump housing via a bearing portion, and the pump chamber formed on the front front side of the pump housing is fixed to the tip end of the drive shaft. An impeller made of synthetic resin is rotatably provided. Further, a mechanical seal is provided between the drive shaft and the pump housing to prevent leakage of cooling water from the pump chamber toward the bearing portion.

JP 2005-291116 A

  By the way, since the inner peripheral side of the mechanical seal is always in sliding contact with the outer peripheral surface of the drive shaft while the pump is driven, the cooling water in the pump chamber is slightly supplied via the impeller in order to suppress seizure. There is a need.

  However, in the water pump described in Patent Document 1, the synthetic resin impeller is not provided with any special means for supplying cooling water from the pump chamber in the mechanical seal direction. For this reason, the cooling water may not be sufficiently supplied to the mechanical seal side, and the mechanical seal may be seized.

  The present invention has been devised in view of the technical problems of the prior art, and provides a water pump that can actively supply cooling water from an impeller to a mechanical seal to suppress burning of the mechanical seal. It is aimed.

The invention according to claim 1 is housed in the pump housing, a pump housing that forms a pump chamber, a drive shaft that transmits rotational power from the outside and is rotatably supported in the pump chamber, A synthetic resin impeller provided at one end of the drive shaft, and a seal member disposed between the drive shaft and the pump housing located behind the impeller,
The impeller includes a base portion formed in a disk shape, a locking means that protrudes along the axial direction at a rotation center position of the base portion, and one end portion of the drive shaft is locked and fixed, and a front surface of the base portion A plurality of blade portions radially provided on the side from the rotation center side, and provided radially from the rotation center side of the base portion, each having a distal end portion extending between the blade portions, and from the front surface of the base portion And a slit portion formed through the rear surface of the seal member side.

  According to the present invention, it is possible to positively supply cooling water from the impeller side to the mechanical seal, and to effectively suppress the seizure of the mechanical seal.

It is A arrow directional view of FIG. 2 which shows one Embodiment of the water pump which concerns on this invention. It is a longitudinal cross-sectional view of the water pump of this embodiment. It is a disassembled perspective view of the water pump of this embodiment. It is a perspective view which shows the impeller provided to this embodiment. It is a perspective view which shows the front-end | tip part of the drive shaft provided to this embodiment. It is a front view of the impeller provided for this embodiment. It is a rear view of the impeller.

  Hereinafter, embodiments of a water pump according to the present invention will be described with reference to the drawings.

  1 to 3 show an embodiment of a water pump according to the present invention. The water pump 1 is applied to a cooling device that circulates antifreeze liquid (ethylene glycol) that is cooling water between a radiator of an automobile and an engine. Yes.

  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 A pulley 4 rotatably supported by a single ball bearing 5 is inserted into the pump housing 2 and is integrally formed with the pulley 4 via a large-diameter shaft portion 6a on one end side. A drive shaft 6, an impeller 7 fixed to the small-diameter shaft portion 6 b on the other end side of the drive shaft 6 and rotatably accommodated in the pump chamber 3, and the pump housing 2 and the drive shaft 6. A mechanical seal 8 interposed between the pump chamber 3 and the ball bearing 5 is mainly configured.

  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 medium-diameter portion 10b in the direction of the large-diameter shaft portion 6a of the drive shaft 6 is formed, and thus a hollow portion 10d having a stepped diameter is formed therein.

  In the middle diameter portion 10 b, 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. In addition, a discharge pipe 14 a is attached to the atmosphere opening hole 14. Further, an annular space 15 is formed between the inner diameter portion 10 b and the drive shaft 6 on the inner peripheral side of the medium diameter portion 10 b, and the annular space 15 is formed by the drain hole 11 and the atmosphere opening hole 14. Is communicated in the vertical direction.

  As shown in FIGS. 2 and 3, the pulley 4 is formed integrally with the drive shaft 6 by a synthetic resin material in a disc shape, and a central portion where the large-diameter shaft portion 6a of the drive shaft 6 is integrally coupled. A fixed portion 4a, a disk-like flange wall 4b extending in the radial direction of the drive shaft 6 from the axial end edge of the central fixed portion 4a, and an axial direction of the drive shaft 6 from the outer peripheral edge of the flange wall 4b It is composed of a bent large-diameter cylindrical portion 4c and a belt mounting portion 4d protruding from the outer peripheral surface of the cylindrical portion 4c.

  The cylindrical portion 4 c is configured such that the outer ring 5 b of the ball bearing 5 is press-fitted and fixed to the inner peripheral surface via a metal cylindrical insert 16. The insert 16 is previously provided integrally with the cylindrical portion 4c via an annular protrusion 16a at the tip during resin molding of the pulley 4, and the axial length thereof is slightly smaller 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.

  In the belt mounting portion 4d, a transmission belt wound around a driving pulley fixed to a tip end portion of a crankshaft (not shown) is wound around an outer periphery formed in a wave shape so that a rotational force is transmitted. It has become.

  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 position in the axial direction is set by press-fitting into the insert 16.

  Bearing seals 17a and 17b made of a pair of annular rubber materials for preventing intrusion of dust and the like are provided at the front and rear ends of the inner ring 5a and the outer ring 5b, respectively. Each of the bearing seals 17a and 17b 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. 3, a thin annular plate-like shielding plate 18 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 18 is disposed 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 drive shaft 6 is formed integrally with the pulley 4 from a synthetic resin material as described above, and has a large diameter formed on the base end side of the pulley 4 side. A shaft portion 6a, a medium-diameter shaft portion 6c formed on the center side and having a smaller diameter than the large-diameter shaft portion 6a, and a small-diameter shaft portion 6b formed on the distal end side and having a smaller diameter than the medium-diameter shaft portion 6c. Are formed in a stepped small diameter from the large diameter shaft portion 6a to the small diameter shaft portion 6b.

  Between the large-diameter shaft portion 6a and the medium-diameter shaft portion 6c, an annular groove 19 having an annular groove 20 that is annularly cut is formed. The annular groove 19 is provided at a position facing the annular space chamber 15, and one end surface on the mechanical seal 8 side is configured as a first step surface 19 a that is a step portion, and the other end surface on the opposite side is formed. The second step surface 19b is configured.

  The first and second step surfaces 19 a and 19 b are formed in a direction perpendicular to the axis of the drive shaft 6, and each outer peripheral edge faces the drain hole 11 and the air release hole 14 through the annular space chamber 15. Yes. The annular groove 19 has an axial width, that is, a width W between the stepped surfaces 19a and 19b 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.

  Further, as shown in FIGS. 1, 2, and 5, the small-diameter shaft portion 6b is formed in a two-sided width shape, and is an engagement groove that is an engagement portion on the distal end side of the parallel side surfaces 6d and 6e. 20 and 20 are formed along the radial direction. Both the engagement grooves 20 and 20 are formed in a substantially rectangular cross section with a predetermined depth, and the front end portion 6f is formed in a projection shape by the both engagement grooves 20 and 20, and is formed in a planar rectangular shape. Yes.

  The impeller 7 is integrally formed of a synthetic resin material, and as shown in FIGS. 1 to 4, a substantially disk-shaped base portion 7 a and a radial shape 8 from the center portion side on the front outer peripheral side of the base portion 21. A blade portion 7b of the sheet, and a locking means 21 that protrudes in the axial direction integrally with the central portion that is the rotation center portion of the base portion 7a and is fixed to the small-diameter shaft portion 6b of the drive shaft 6; It is composed of

  The base portion 7a is formed to have a predetermined thickness and rotates with a gap on the rear surface of the pump chamber 3.

  Each of the eight blade portions 7b has a concave curved shape on one side in the rotational direction of the impeller 7, and each inner peripheral end 7c is disposed at a position spaced apart from the locking means 21 by a predetermined length. In addition, the outer peripheral end 7d extends to the outer peripheral edge of the base portion 7a.

  As shown in FIGS. 1, 2, and 4, the locking means 21 includes a pair of halved cylindrical portions 22 and 22 through which the small-diameter shaft portion 6 b of the drive shaft 6 is inserted in the internal axis direction. A pair of locking pieces 23, 23 provided between the opposing surfaces of the cylindrical portions 22, 22 in the circumferential direction and locked to the respective engaging grooves 20, 20 of the small-diameter shaft portion 6 b. Yes.

  The cylindrical portions 22 and 22 protrude from the center of the front surface of the base portion 7a, and the amount of protrusion is set to be shorter than each blade portion 7b. An insertion hole 22a having a substantially rectangular cross section through which the portion 6b is inserted is formed through.

  Both the locking pieces 23, 23 are formed in an elongated rectangular plate shape and face each other with a certain gap therebetween, and a base end portion rises integrally from the base portion 7a, and each tip end side is a base end. They are formed so as to be elastically deformable in the direction of expansion and contraction with respect to each other. A pair of locking claws 23a and 23a that are locked to the respective engaging grooves 20 and 20 of the small-diameter shaft portion 6b are integrally provided on the opposing inner surfaces of both distal ends of the both locking pieces 23 and 23. Yes.

  The width of the gap between the locking pieces 23 and 23 is set to be slightly larger than the width of the small-diameter shaft portion 6b, and both side surfaces 6d and 6e of the small-diameter shaft portion 6b are in sliding contact with each inner surface. It is designed to be inserted through.

  The engaging claws 23a, 23a are formed in a shape substantially similar to the engaging grooves 20, 20 of the small-diameter shaft portion 6b, and the engaging grooves 20, 20 are caused by the elastic return force of the engaging pieces 23, 23. To be engaged.

  Further, as shown in FIG. 1, a pair of recesses 24, 24 are formed on the back side of each of the locking pieces 23, 23 between the circumferential portions of the cylindrical portions 22, 22. ing.

  As shown in FIGS. 1, 4, 6 and 7, the base portion 7a of the impeller 7 has a total of four slit portions as a pair from both side surfaces of the locking pieces 23, 23, respectively. 25a, 25b, 26a, and 26b are formed from the rotation center side toward the outer peripheral side, and are formed so as to penetrate from the front surface to the back surface of the base portion 7a.

  In other words, the pair of slit portions 25a and 25b on the one side and the pair of slit portions 26a and 26b on the other side are respectively both side surfaces of the one locking piece 23, 23, that is, the tubular portions 22 and 22 respectively. And extending in the radial direction with the opposite inner surface as a base end, and is formed in a curved shape along the concave inner surface of each of the corresponding blade portions 7b. The one slit portions 25a and 26a are formed in a curved shape that is almost linear, while the other slit portions 25b and 26b are formed in a curved shape that is close to an arc shape, and each notch width is It is set to about 0.5 mm.

  Moreover, the length of these slit parts 25a-26b is set from the inner side of the opposing inner surface of each said cylindrical parts 22 and 22 to the outer periphery vicinity of the said base 7a.

  Furthermore, round holes 27a to 27d are formed at the respective tip portions of the slit portions 25a to 26b. The round holes 27a to 27d are formed in the shape of raindrops and are formed in a continuous shape from the slit portions 25a to 26b.

  As shown in FIG. 2, the mechanical seal 8 is a general one, and includes a cartridge portion 8a fixed to the inner peripheral surface of the intermediate diameter portion 10b of the cylindrical portion 10, and an inner portion of the cartridge portion 8a. The sleeve portion 8b is disposed on the peripheral side and is in sliding contact with the outer peripheral surface 6c of the drive shaft 6.

[Effects of this embodiment]
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 drive 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, a part of the cooling water in the pump chamber 3 that has become high pressure passes through the slit portions 25a to 26b and the round holes 27a to 27d, for example, along the outer peripheral surface of the drive shaft 6. It flows in the direction of the mechanical seal 8. For this reason, the sleeve portion 8b of the mechanical seal 8 is positively cooled by the cooling water, and seizure due to sliding friction with the drive shaft 6 can be effectively suppressed.

  In particular, since each of the slit portions 25a to 26b is formed along each blade portion 7b, the cooling water collected in the concave portion of each blade portion 7b as the impeller 7 rotates is directly moved to the base portion 7a side. It is guided and easily guided to the slit portions 25a to 26b. As a result, the fluid quickly flows in the direction of the mechanical seal 8 through the slit portions 25 a to 26 b and is used for cooling the mechanical seal 8.

  Moreover, it becomes easy to allow the cooling water to flow in the direction of the mechanical seal 8 also from the respective round holes 27a to 27d provided at the tip portions of the respective slit portions 25a to 26b.

  Since the drive shaft 6 and the impeller 7 are formed of a synthetic resin material instead of a metal material, the weight of the drive shaft 6 and the impeller 7 can be reduced, and the rotational responsiveness of the drive shaft 6 and the impeller 7 is improved due to a decrease in inertia mass.

  Further, when the impeller 7 is attached to the drive shaft 6, when the distal end portion of the small diameter shaft member 6 b of the drive shaft 6 is pushed into the rectangular insertion hole 22 a of the impeller 7 and inserted, the locking pieces 23, 23 are inserted. Allows the insertion of the small-diameter shaft portion 6b while expanding and deforming by its own elastic force. When further pushed and inserted, the pair of stopper surfaces 6f formed on the end edges of the both side surfaces 6d and 6e are brought into contact with each other to restrict further insertion, and the locking pieces 23 and 23 are reduced in diameter to the original shape. While being deformed, the engaging claws 23a and 23a engage with the engaging grooves 20 and 20 of the small diameter shaft portion 6b. Thereby, the impeller 7 can be stably and reliably attached to the drive shaft 6 while being prevented from rotating.

  Further, since the impeller 7 can be attached to the drive shaft 6 with one touch, the attaching operation becomes extremely easy.

  The rotating base portion 7a is deformed when a load of cooling water received by each blade portion 7b is applied, or when the blade portion 7b is inserted into the insertion hole 22a of the impeller 7 of the drive shaft 6, and the slit portions 25a to 25a are deformed. There is a possibility that stress concentration occurs on the tip end side of 26b, but since the respective round holes 27a to 27d are formed in the tip end portion, the stress concentration can be relaxed. Generation | occurrence | production of the crack etc. by the front-end | tip part side can fully be suppressed.

  Further, most of the cooling water flowing in the direction of the mechanical seal 8 is restricted from flowing into the proximal end portion of the drive shaft 6 by the mechanical seal 8, but a part of the cooling water is, for example, of the mechanical seal 8. It leaks from the sliding seal portion 8c and flows along the outer peripheral surface 6c of the drive shaft 6 toward the large-diameter shaft portion 6a. When the flowing cooling water reaches the first step surface 19 a, it is cut at the outer peripheral edge of the first step surface 19 a with the action of the rotational centrifugal force of the drive shaft 6, and is drained through the annular space chamber 15. It is dropped into the drain chamber 12 from the hole 11 and collected and stored here.

  That is, since the outer peripheral edge of the first step surface 19 a is formed perpendicular to the drive shaft 6, the cooling water transmitted through the outer peripheral surface 6 c is quickly cut off from the drain hole 11. It is dropped and stored in the drain chamber 12.

  Therefore, most of the leaked cooling water does not reach the second stepped surface 19b side through the outer peripheral surface of the annular groove 19c by the effective draining action of the first stepped surface 19a.

  In addition, even if the cooling water adhering to the outer peripheral surface of the annular groove 19c slightly flows along the outer peripheral surface of the annular groove 19c in the direction of the large-diameter shaft portion 6a, the outer surface travels along the second step surface 19b. It is cut by the peripheral edge 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 passes through the annular space chamber 15 and the air opening hole 14 through the discharge pipe 14a. Discharged outside.

  As described above, most of the cooling water leaking from the mechanical seal 8 and transmitted to the outer peripheral surface 6c of the drive shaft 6 is effectively cut off by the first step surface 19a, and enters the drain chamber 12 from the drain hole 11. Since the liquid drops, the flow into the ball bearing 5 can be sufficiently suppressed.

  Moreover, even if it slightly flows along the outer peripheral surface of the annular groove 19 c and flows toward the large-diameter shaft portion 6 a, it is effectively cut at the outer peripheral edge of the second step surface 19 b 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.

  Further, since the inside of the ball bearing 5 is sealed by the bearing seals 17a and 17b, it becomes possible to further prevent the penetration of cooling water and water vapor into the ball bearing 5.

  Further, the shielding plate 18 can also prevent entry of dust and the like into the ball bearing 5 from the vicinity of the outside of the medium diameter portion 10b.

  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 annular groove 19c is formed in a simple cylindrical shape, it can be easily formed by grinding after the drive shaft 6 is formed.

  The present invention is not limited to the configuration of the above-described embodiment, and the number of the slit portions 25a to 26b can be further reduced to 3 to 1 or vice versa. Is possible.

  The cross-sectional shape of the locking claws 23a, 23a can be triangular or quadrangular.

  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 or 2,
The water pump according to claim 1, wherein the slit portion is formed along a shape of the blade portion.

  According to this invention, part of the cooling water that has flowed along the blade portion can easily flow out from the slit portion toward the bearing portion.

[Claim b] In the water pump according to any one of claims 1 to a,
While forming one end portion of the drive shaft in a two-sided width shape and forming engaging portions on both side surfaces on the distal end side of the one end portion,
The locking means is provided between a pair of half-cylindrical insertion portions that allow the one end portion of the drive shaft to be inserted in the internal axial direction, and the one end portion of the drive shaft that is inserted between the opposing surfaces of the both insertion portions. A pair of locking pieces on the inner surface facing each other, and both the locking pieces can be elastically deformed in the expansion / contraction direction with the insertion of one end of the drive shaft. A water pump characterized by being formed.

[Claim c] In the water pump according to claim b,
The slit portion extends in a radial direction substantially in parallel from both sides of one locking piece of the locking means, and is formed in a double shape bent in a curve along the two adjacent blade portions. A water pump characterized by

[Claim d] The water pump according to claim c,
The water pump according to claim 1, wherein a pair of the two slit portions are provided at substantially right and left target positions centering on both locking pieces of the locking means.

[Claim e] In the water pump according to any one of claims 1 to d,
A water pump, wherein a round hole is formed at a tip portion of each slit portion.

  When one end portion of the drive shaft is inserted between the insertion portion and the locking pieces, and the locking pieces are elastically deformed in the diameter increasing direction via the locking claws, the tip ends of the slit portions However, in the present invention, since the round hole is formed at the tip, the generation of the concentrated stress can be sufficiently suppressed, and the occurrence of cracks and the like can be eliminated.

[Claim f] In the water pump according to any one of claims b to e,
A water pump, wherein a recess is formed on an outer surface side of the locking piece.

According to this invention, a part of the cooling water that has flowed into the front side of the impeller is collected in the concave portion, and flows from here through the slit portion toward the bearing portion. It functions as a guide for the cooling water in the direction of the slit.
[Claim g] In the water pump according to any one of claims b to e,
The water pump is characterized in that the distance from the center of rotation of the impeller to the outside of the locking piece is smaller than the distance to the outer periphery of the insertion portion.

According to this invention, since the cooling water that has flowed into the impeller front side is easier to flow on the outer surface of the locking piece than on the outer surface of the insertion portion, it is easier to collect the cooling water outside the locking piece. Become.

DESCRIPTION OF SYMBOLS 1 ... Water pump 2 ... Pump housing 3 ... Pump chamber 4 ... Pulley 6 ... Drive shaft 6a ... Large diameter shaft part 6b ... Small diameter shaft part 6c ... Medium diameter shaft part 6d, 6e ... Both side surfaces 6f ... Stopper surface 7 ... Impeller 7a ... Base 7b ... Bane 8 ... Mechanical seal (seal member)
8a ... cartridge part 8b ... sleeve part 10 ... cylindrical part 10b ... medium diameter part 11 ... drain hole 12 ... drain chamber 14 ... air release hole 15 ... annular space chamber 20 ... engagement groove (engagement part)
21 ... Locking means 22 ... Cylindrical portion 22a ... Insertion hole 23 ... Locking portion 23a ... Locking claws 25a-26b ... Slit portions 27a-27d ... Round holes

Claims (2)

A pump housing forming a pump chamber;
A driving shaft that transmits rotational power from the outside and is rotatably supported in the pump chamber;
A synthetic resin impeller housed in the pump chamber and provided at one end of the drive shaft;
A seal member disposed between the drive shaft located behind the impeller and the pump housing, and
The impeller is
A base formed in a disk shape;
A locking means that protrudes along the axial direction at the rotation center position of the base portion, and one end portion of the drive shaft is locked and fixed;
A plurality of blade portions provided radially on the front side of the base portion from the rotation center side;
A slit portion provided radially from the rotation center side of the base portion, each having a distal end portion extending between the blade portions, and penetrating from the front surface of the base portion to the rear surface of the seal member;
A water pump comprising: A pump housing forming a pump chamber;
A driving shaft that transmits rotational power from the outside and is rotatably supported in the pump chamber;
A synthetic resin impeller housed in the pump chamber and provided at one end of the drive shaft;
A seal member disposed between the drive shaft located behind the impeller and the pump housing, and
The impeller is
A base formed in a disk shape;
A locking means that protrudes along the axial direction at the rotation center position of the base portion, and one end portion of the drive shaft is locked and fixed;
A plurality of blade portions provided on the front side of the base portion from the rotation center side toward the outer peripheral side;
A cutout is formed from the rotation center side to the outer peripheral side of the base part , and the tip part side extends between the blade parts, and a part of the cooling water introduced to the front side of the base part is supplied to the seal member. A slit part that flows out to the side,
A water pump comprising:

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