The present invention relates to both a water pump used for pumping a cooling water into an interior of an internal combustion engine to cool the internal combustion engine, and a method for producing the water pump.
As a hitherto used water pump, the pump described in Patent Document-1 is known.
Outline of the hitherto used pump will be described. The water pump has a pump housing having therein a pump chamber, a drive shaft rotatably supported in the pump chamber, a pulley connected to one end of the drive shaft through a discal end wall, a ball bearing provided between the pulley and the pump housing to rotatably support the pulley, an impeller connected to the other end of the drive shaft to integrally rotate therewith and a mechanical seal provided between the impeller and the pulley.
The discal end wall is formed with a plurality of through holes that are arranged in a circumferential direction at evenly spaced intervals. Each of the through holes has such functions as to allow insertion of a tool therethrough to press an outer race of the ball bearing onto an inner cylindrical surface of the pulley at the time of assembling the water pump and as to allow water leaked from the interior of the pump housing through the mechanical seal to be discharged to the outside.
In the water pump described in the Patent Document-1 however, the through holes are placed near the center of the discal end wall. Due to such placement of the through holes, the function as to allow discharging of leaked water through the mechanical seal to the outside becomes poor, and due to the leaked water poor discharging, it often occurs that foreign substances such as water, dust and the like that might enter the pump housing (viz., into the ball bearing) through the through holes are not easily discharged to the outside.
The present invention is provided by taking the actual situation of the hitherto used water pump into consideration and aims to provide a water pump that is improved in dischargeablity of foreign substances such water, dust and the like to the outside through the through holes.
Patent Document-1: Japanese Laid-open Patent Application (tokkai) 2004-116486
The invention defined in claim 1 relates to a water pump, particularly to a feature of the water pump in which a discal end wall of a pulley is formed with a plurality of through holes that extend in an axial direction to connect inside and outside of the end wall, and each of the through holes is formed at a radially outer side of an inner peripheral surface thereof with a pathway groove that penetrates approximately along an inner peripheral surface of the tubular base section in a radially outside direction.
In accordance with the present invention, the dischargeablity of water or the like to the outside through the through holes can be improved.
In the following, embodiments of the water pump of the present invention will be described in detail with reference to the accompanying drawings.
The water pump shown is applied to a cooling device by which an unfreezing fluid (ethylene glycol) viz., cooling water is recirculated between a radiator and an internal combustion engine of a motor vehicle.
As is seen from
The pump housing 1 is integrally constructed of an aluminum alloy, and has both a housing body 8 that defines therein the pump chamber 2 and has an annular ring like shape and a stepped cylindrical portion 9 that projects backward from the housing body 8.
The housing body 8 has an annular flat mounting face 8a that is to be in contact with a flat face possessed by a side part of the cylinder block and has at a peripheral portion thereof a plurality of boss portions 8c with respective bolt holes 8b through which connecting bolts pass to be screwed to the cylinder block.
In the housing body 8, there is defined an outlet port 8d from which a cooling water, which has been led into the pump chamber 2 from an inlet port located at the side of a radiator (not shown), is discharged to a water jacket of the cylinder block in response to rotation of the impeller 6.
As is seen from
The medium diameter part 9b is formed at a gravitationally lower portion thereof with a vertically extending drain hole 10 for draining drops of water that may leak from the mechanical seal 7, and at a lower side of the drain hole 10, there is formed a drain chamber 11 for reserving therein the water drops, the drain chamber being constructed to straddle an interior of the larger diameter part 9a. A lower open end of the drain chamber 11 is hermetically sealed by a drain cap 12.
The medium diameter part 9b is formed at a gravitationally upper portion thereof with an atmosphere-open hole (not shown) through which the cooling water that might leak from the mechanical seal 7 and vapor of the cooling water that might be reserved in the drain chamber 11 are discharged to the outside. Furthermore, between an inner cylindrical surface of the medium diameter part 9b and the drive shaft 5, there is defined an annular space chamber 13 that is communicated with both the drain hole 10 and the atmosphere-open hole in an up-and-down direction. An outer cylindrical wall of the medium diameter part 9b is formed with an atmosphere-open passage (not shown) through which the above-mentioned atmosphere-open hole is communicated with the outside.
The ball bearing 3 is of a conventional type, and as is seen from
The inner race 3a takes the most pressed axial position by being pressed against an annular projected portion 9d formed at a front end of the medium diameter part 9b of the cylindrical portion 9, and the outer race 3b is pressed or positioned to a certain position in the pulley 4 due to the positioning of the inner race 3a.
As is seen from
The first seal member 14 is tightly put between the annular projected portion 9d of the medium diameter part 9b and one end of the inner race 3a. While, the second seal member 15 is tightly put between the other end of the inner race 3a and a retainer 16 that is a holding member.
As is seen from
As is seen from
The cylindrical part 4e is formed with an air bleed through opening 4f that effects air bleeding when the end part 5a of the drive shaft 5 is press-fitted into a center position of the bottom wall of the cylindrical part 4e.
The above-mentioned belt-holding part 4d has an outer surface whose vertical section is shaped like wave-like teeth. Although not shown in the drawing, around the belt-holding part 4d, there is put a part of a transmission belt that has another part put around a drive pulley fixed to a leading end of a crankshaft, so that transmission of a rotation force is carried out.
As is seen from
The end part 5a and the other end part 5b are generally the same in outer diameter and the outer diameter of the smaller diameter shaft part 5c is smaller than that of the end parts 5a and 5b. The smaller diameter shaft part 5c is exposed to the annular space chamber 13 so that leaked water from the mechanical seal 7 and thus running on the cylindrical outer surface is cut or separated by opposed stepped edges 5d and 5e before being guided into the drain chamber 11 from the annular space chamber 13 through the drain hole 10.
The impeller 6 is integrally constructed of a metal material such as aluminum alloy or the like, and as is seen from
The base part 6a is shaped to have a given thickness and arranged to rotate behind a back face of the pump chamber 2 with a certain clearance kept therebetween. The tubular fixing part 6b is formed with an axially extending fixing hole 6d into which the other end part 5b of the drive shaft 5 is press-inserted.
The mechanical seal 7 is of a commonly used type and comprises a cartridge part 7a that is fixed to an inner cylindrical surface of the medium diameter part 9b of the cylindrical portion 9, a sleeve part 7b that is supported on an outer cylindrical surface of the drive shaft 5, and a seal part (not shown) that is arranged between an inner cylindrical side of the cartridge part 7a and an outer cylindrical side of the sleeve part 7b and makes a sliding movement relative to the cartridge part and the sleeve part.
As is seen from
At a circumferentially middle position of each arcuate bottom face 17c, there is formed a pathway groove 17d. As is seen from
In the following, the process for producing the pulley 4 by press-forming will be described with reference to
In a first step, as is seen from
In a second step, as is seen from
In a third step thereafter, as is seen from
Then, in a fourth step, as is seen from
Then, in a fifth step, as is seen from
That is, the stamping tool 20 comprises a discal base part 20a and six punching rods 20b that are projected from a front end of the discal base part 20a, and each punching rod 20b has a transverse section that includes the triangular shape of the above-mentioned Japanese triangular rice ball (viz., Sankaku Onigiri) and the V-shape of the pathway groove 17d in section, that are provided for each through opening 17. The diameter of a circular path that connects radially outer edges of the six punching rods 20b is slightly smaller than a diameter of the inner cylindrical surface 4g of the cylindrical base part 4b, so that when the punching rods 20b are inserted into the cylindrical base part 4b, the radially outer edge of each punching rod 20b does not contact the inner cylindrical surface 4g.
Furthermore, in the present embodiment, considering the view of the transverse cross section of each punching rod 20b, the part corresponding to the cross section of the pathway groove 17d is made smaller than the part of the through opening 17 and the width length of the part corresponding to the pathway groove 17d is continuously reduced as the position is shifted radially outward. With this feature, even when, upon insertion of the punching rods 20b into the cylindrical base part 4b, a little shaft drift occurs, undesired contact of the radially outer edge of each punching rod 20b with the inner cylindrical surface 4g can be suppressed.
Accordingly, when the punching rods 20b of the stamping tool 20 are inserted into the cylindrical base part 4b to punch the flange wall 4a through the engaging holes 19b of the supporting tool 19, the six through openings 17 and the pathway grooves 17d are produced at the same time. With this action, a series of press-forming steps for the pulley 4 is finished.
As is mentioned hereinabove, in the present embodiment, the through openings 17 are formed at the outer peripheral side of the flange wall 4a and the leading ends of the pathway grooves 17d take the same position as the position of the inner cylindrical surface 4g of the cylindrical base part 4b, and thus, water, dust and the like that might be present in the cylindrical base part 4b can be effectively discharged to the outside.
That is, even when water that might leak from the mechanical seal 7 during operation of the pump flows to a front portion in the cylindrical base part 4b or even when water and dust intrude into the front portion in the cylindrical base part 4b through the through openings 17, such foreign things can be speedily discharged to the outside from a lower part of the inner cylindrical surface 4g of the cylindrical base part 4b particularly when the pump is stopped. Thus, the function of discharging water and the like from the interior of the cylindrical base part 4b to the outside is highly increased.
Accordingly, water and dust that might enter into the front area in the cylindrical base part 4b are suppressed from flowing toward the ball bearing 3, and thus, generation of rust inside the ball bearing 3 can be sufficiently suppressed.
Each through opening 17 of the second embodiment shown in
Each through opening 17 of the third embodiment shown in
Through openings 17 of the fourth embodiment shown in
Each through opening 17 of the fifth embodiment shown in
Each through opening 17 of the sixth embodiment shown in
Accordingly, due to presence of the pathway groove 17d (17d) of each through opening, the above-mentioned second to sixth embodiments have such an operation effect that the performance for discharging water and dust is increased like in case of the first embodiment.
In case of the fifth embodiment, due to presence of the two pathway grooves 17d and 17d, the performance for discharging water and dust is much increased.
That is, each through opening 17 of the seventh embodiment shown in
Accordingly, in this embodiment, water that might enter into the interior of the cylindrical base part 4b is discharged to the outside while being guided through the relatively broad bottom face 17c of the through opening 17, and thus, a flow resistance becomes small and thus the discharge performance is further increased.
Each through opening 17 of the eighth embodiment shown in
Accordingly, also in this embodiment, the water that might enter into the interior of the cylindrical base part 4b is discharged to the outside while being guided through the relatively broad outer edge 17e of the through opening 17, and thus, a flow resistance becomes small and thus the discharge performance is further increased.
That is, each through opening 17 of the ninth embodiment shown in
The pathway groove 17d is placed at a position radially outside the position of the inner cylindrical surface 4g of the cylindrical base part 4b. That is, the pathway groove has a stepped surface that is depressed by one step relative to the inner cylindrical surface 4g, unlike in the case of the above-mentioned embodiments in which each pathway groove takes the same position as the position of the inner cylindrical surface 4g.
Accordingly, in this embodiment, the water that might enter into the interior of the cylindrical base part 4b is discharged to the outside while being guided through the broad and low stepped pathway groove 17d of the through opening 17, and thus, a discharging flow speed of the water is increased and thus the discharge performance is much more increased.
This special construction can exhibit a satisfied discharge performance regardless of the position where the through openings 17 take at the time when the pump is now working.
Each through opening 17 of the tenth embodiment shown in
Like in the ninth embodiment, the pathway groove 17d is placed at a position radially outside the position of the inner cylindrical surface 4g of the cylindrical base part 4b. That is, the pathway groove has a stepped surface that is depressed by one step relative to the inner cylindrical surface 4g.
Accordingly, in this embodiment, the discharge performance for water and the like is increased like the ninth embodiment.
The pathway groove 17d is an elongate cut shaped rectangular and extends radially outward from the bottom surface 17c, and a radially outer edge 17f of the pathway groove extends to the outer cylindrical surface of the cylindrical base part 4b passing over the inner cylindrical surface 4g of the cylindrical base part 4b thereby to constitute an entire construction shaped like a gutter.
Accordingly, in this embodiment, the water and the like that might enter into the interior of the cylindrical base part 4b is directly led to the pathway groove 17d of the through opening 17 from a lower part of the inner cylindrical surface 4g of the cylindrical base part 4b and continuously moved downward and discharged to the outside. Accordingly, the water discharge performance is further increased.
Number | Date | Country | Kind |
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2013-270934 | Dec 2013 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2014/079208 | 11/4/2014 | WO | 00 |