Patent Grant
6960066
This application is based on and claims priority under 35 U.S.C. § 119 with respect to Japanese Patent Application No. 2002-045201 filed on Feb. 21, 2002, Japanese Patent Application No. 2002-054039 filed on Feb. 28, 2002 and Japanese Patent Application No. 2003-044215 filed on Feb. 21, 2003 the entire content of which are incorporated herein by reference.
The present invention relates to a water pump. More particularly, the present invention pertains to a water pump for a vehicle.
A known water pump disclosed in Japanese Patent Laid-Open Publication No. H11-336699, a body is fixed to a cylinder block with a fixing member such as bolt, a solid rotational shaft is rotatably supported by the body via a bearing, a pulley is fixed to one end of the rotational shaft via a pulley bracket with a fixing member such as bolt, an impeller is press fitted to be secured to the other end of the rotational shaft, and the impeller and the pulley are rotated as one unit. With the water pump disclosed in Japanese Patent Laid-Open Publication No. H11-336699, the rotational shaft and the pulley are provided separately and are fixed each other by the fixing member. Therefore, the number of the components of the water pump is increased and the structure thereof becomes complex.
A need thus exists for a water pump which has a simple structure while maintaining the strength of the rotational shaft.
In light of the foregoing, the present invention provides a water pump which includes a rotation member, a hollow shaft portion having an opening on one end and connected to the rotation member for unitary rotating with the rotation member, an impeller connected to the shaft portion for unitary rotating with the shaft portion, a body defining a fluid chamber in which the impeller is rotated, a bearing for rotatably supporting the shaft portion on the body, a sealing member provided between the shaft portion and the body for sealing the fluid chamber and a cover portion for substantively closing the opening of the shaft portion.
The foregoing and additional features and characteristics of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawing figures in which like reference numerals designate like elements.
Embodiments of a water pump will be explained with reference to the illustrations in the drawing figures. Referring to
As shown in
A pulley 20 formed with an external peripheral portion 21 having a concave configuration is outfitted to an outer ring of the bearing 14 to be unitary rotated. Engaging bores 23 are formed on an external peripheral surface 21a of the external periphery portion 21 outfitted to the bearing 14 keeping equal angular interval one another. A cylindrical cover 24 having a bottom is provided on a front (i.e., left side of
An impeller 30 is unitary rotatably fixed to the right end portion of the shaft portion 25. The impeller 30 includes a base portion 30a, a plurality of vanes 30b projected from a peripheral portion of the right surface of the base portion 30a, and a hollow projection portion 30c projected from the central portion of the base portion 30a in the right direction of
The mechanical seal 50 is provided on one end side (i.e., boarder with the water chamber 95) of a cylindrical space 26 defined between the external peripheral surface of the shaft portion 25 and an internal peripheral surface of the large diameter portion 12a and the small diameter portion 12b. The water chamber 95 is water tightly separated from the outside by the mechanical seal 50 so that the cooling water is not leaked to the outside. The mechanical seal 50 includes a fixing ring 50a fixed to the internal peripheral side of the larger diameter portion 12a of the cylindrical portion of the body 12 and a rotational ring 50b fixed to the shaft portion 25 for contacting the fixing ring 50a for always establishing the fluid tight relationship and relative rotational relationship relative to the fixing ring 50a.
The operation of the water pump according to the first embodiment will be explained as follows. The pulley 20 is rotated by the rotational force transmitted from the output shaft of an engine (not shown) via a belt 85 engaged with a belt engaging surface 20b of the pulley 20. In accordance with the rotation of the pulley 20, the shaft portion 25 unitary formed with the pulley 20 is rotated in the identical direction with the pulley 20. The impeller 30 unitary connected to the shaft portion 25 is rotated in the water chamber 95 which is blocked by the body 12.
Because the water chamber 95 is filled with the cooling water, the impeller 30 moves the cooling water around the center of the water chamber 95 towards the external peripheral direction of the impeller 30 by the centrifugal force caused by the rotation of the impeller 30. Thus, the pumping operation by the centrifugal force is generated from the center of the impeller 30 to the external direction. Accordingly, the differential pressure is generated between the rotational center of the impeller 30 in the water chamber 95 and the external peripheral side of the water chamber 95. And thus, the cooling water is sucked from a suction portion 95a provided around the rotational center of the impeller 30 into the water chamber 95. The cooling water is pressurized to be sent to the external peripheral side by the pumping operation of the impeller 30 to be supplied to portions to be cooled of the engine from an outlet portion (not shown) provided on the external peripheral sides. The cooling water is circulated in the foregoing manner.
According to the water pump of the first embodiment of the present invention, the opening of the shaft portion 25 is substantively closed with the cover 24. In case the pump 10 is assembled to the engine body provided in the engine compartment, the water droplet may be applied to the surface of the pump 10 due to the water splash during the vehicle driving. Even in this case, the opening of the shaft portion 25 is substantively closed by the cover 24. Thus, the invasion of the dump and the water droplet to the opening portion can be securely prevented with a simple construction.
Normally, the inside of the shaft portion formed by the press molding is unlikely to be successfully treated by the surface finishing and is apt to be eroded (e.g., rusted). With the water pump of the second embodiment, because the opening is substantively closed, the invasion of the water droplet from the outside can be prevented and the erosion in the shaft portion can be prevented. With this construction, the decline of the strength of the shaft portion 25 due to the rusting in the shaft portion and the water leakage due to the damage of the shaft portion 25 can be prevented and the fitting strength between the pulley 20 and the bearing 14 is increased to prevent the dropping out of the belt from the pulley 20.
As shown above, with the water pump according to the first embodiment, the mechanical 50 is provided between the external peripheral surface of the shaft portion 25 and the internal peripheral surface of the large diameter portion 12a of the body 12. Although the water droplet leaked via the mechanical seal 50 is to be leaked via a draining bore 22b and the through-bores 22a, the leaked water droplet is not drained to the outside by being retained in an annular space 27 formed between the cover 24 and the pulley 20. Thus, it is unlikely to be misjudged that the water leakage is caused in the water pump 10 being observed from the outside and is unlikely to misjudge the water leakage to mislead the exchange of the water pump 10. In addition, because the cover 24 is provided, the leaked water droplet (i.e., LLC) scattered around the water pump due to the rotation of the water pump 10 is not applied to the parts in the engine compartment and the driving belt 85 of the water pump 10. Vapor shaped leaked water is discharged from the small hole 24d. Thus, the defective operation due to the application of the water droplet is prevented. Further, because the cover 24 prevents the invasion of the external object such as sand and pebbles via the through-bores 22a from the outside, the defective operation causing the water leakage due to the invasion of the external object in the sliding portion of the mechanical seal is prevented. Further, since the nail portions 24c are formed on the flange portion 24b constituting the annular apace 27, the fixing means can be miniaturized.
According to the first embodiment of the present invention, the scattering of the leaked water droplet by the rotation of the pulley leaked via the mechanical seal, the drain bore, and the through bores can be prevented because the through bores are covered with the cover. In addition, the water leakage caused by the invasion of the external object into the sliding portion of the mechanical seal is prevented by the cover for covering the through bores.
With the first embodiment of the present invention, the water droplet leaked via the mechanical seal, the drain bore and the through bores is temporarily retained.
A second embodiment of the water pump of the present invention will be explained referring to
The pulley 110 is made from a plate member made of metal such as steel by press molding. The pulley 110 includes a cylindrical configuration having a concave portion 110g in the center and a plurality of groove portions 110e on the external peripheral surface in the axial direction. The groove portions 110e of the pulley 110 are provided with a belt having a core wire made of material which is flexible (e.g., alamido fiber) to be connected to the crankshaft and the camshaft so that the pulley 110 rotates synchronized with the rotation of the camshaft for controlling the intake and exhaust air of the engine and the crankshaft of the engine. The pulley 110 can be rotated while maintaining a constant belt tension. That is, the belt is provided on the groove portions 110e of the external peripheral surface of the pulley 110 to drive the pulley 110 so that the pulley 110 is rotatably supported relative to the housing 160 which is not rotated.
The shaft portion 120 which is formed by press molding the metal plate is fixed to the concave portion 110g of the pulley 110 by press fitting (e.g., welding) so that the pulley 110 is unitary rotated with the shaft portion 120. The center of the shaft portion 120 includes an opening 125 on one side in the axial direction and an annular concave portion is formed on the external peripheral portion. The concave portion in the axial direction of the shaft portion 120 is formed by a cylindrical portion 120e projected in the axial direction. The cylindrical portion 120e is formed by extending the end of the central portion of the shaft portion 120 in the radial direction, then by bending the end in the axial direction which is the same extended direction of the central portion of the shaft portion 120.
The shaft portion 120 and the pulley 110 are coaxially formed, the cylindrical portion 120e of the shaft portion 120 is fitted into the concave portion 110g of the pulley 110 so that the pulley 110 and the shaft portion 120 are unitary rotated. In this case, the opening of the shaft portion 120 in the axial direction is covered with a closing-portion 110d formed on the axial end portion of the pulley 110. The shaft portion 120 is formed with an opening 120f on one end of the end portion 120c in the axial direction extended in the radial direction of the shaft portion 120. The pulley 110 is formed with an opening 110f on an axial end portion of the closing portion 110d of the pulley 110 at a position corresponding to the opening 120f in the radial direction under the condition that the shaft portion 120 is press fitted into the concave portion 110g.
The impeller 130 includes a disc shaped or propeller shaped base portion 130b and the vanes 130c projected from the base portion 130b in the axial direction. A concave portion 130a in which the cylindrical axial end portion 120g of the shaft portion 120 is provided is formed in the center of the base portion 130b of the impeller 130. The axial end portion 120g on the housing side of the shaft portion 120 is press fitted to be fixed to the concave portion 130a and the impeller 130 is unitary rotated with the pulley 110.
On the other hand, the housing 160 (e.g., engine body) equipped with the water pump 101 is provided with an intake port and an outlet port (not shown). The housing 160 is formed with a recess portion 161 in which the fluid such as the cooling water and the lubrication oil (i.e., the cooling water in this embodiment) is flowed. When the impeller 130 is rotated, the cooling water is flowed from the inlet port to the outlet port. The engine is cooled down by the cooling water passing through the engine to absorb the heat of the engine.
The body 164 of the pump 101 for assembling the water pump 101 relative to the housing 160 is provided on an end of the housing 160. Although the housing 160 corresponds to the engine body in this embodiment, the housing 160 may be formed by aluminum die casting. The housing 160 may be constructed unitary with a cylinder block of the engine or a timing belt case.
The body 164 includes approximately disc shape which is made from a plate member such as steel plate having corrosion resistant treatment and press molded. As shown in
The space constructs a fluid chamber (e.g., water chamber in case the cooling water is filled) 170. The impeller 130 is rotatably provided in the water chamber 170.
An axial sealing member 150 is press fitted to be fixed to an internal peripheral surface 164d of the stepped portions 164b of the body 164. An external peripheral surface 150b of the axial sealing member 150 is press fitted to be fixed not to be relatively rotatable to the internal peripheral surface 164d. On the other hand, an internal peripheral surface 150a of the axial sealing member 150 contacts an external peripheral surface 120a of the shaft portion 120. The axial sealing member 150 is assembled to the shaft portion 120 to be slidable relative to the shaft portion 120 while maintaining the sealing performance of the water chamber 170 with the axial sealing member 150. In this case, the shaft portion 120 is rotatably supported by the body 164 so that the shaft portion 120 is relatively rotatable to the shaft portion 120 under the condition that the sealing performance at both sides of the axial sealing member (shown in
An inner ring 140a of the bearing 140 is pressed fitted to be fixed to an external peripheral surface 164e of an internal diameter end portion 164c having a cylindrical shape of the body 164. The inner ring 140a is fixed not to be relatively rotated. On the other hand, an outer ring 140b of the bearing 140 is press fitted to an internal peripheral surface of the cylindrical portion 120e of the shaft portion 20 not to be relatively rotatable to the pulley 110. In the second embodiment, the bearing 140 includes a known rolling bearing. Thus, the pulley 110 is rotatably supported by the bearing 140 relative to the body 164 fixed to the housing 160.
The operation of the water pump according to the second embodiment of the present invention will be explained as follows.
The rotational force from a crankshaft which corresponds to an output shaft of an engine drives a belt provided on an external peripheral surface of an external diameter of the pulley 110 to rotate the pulley 110. When the pulley 110 is rotated, the shaft portion 120 which is press molded unitary with the pulley 110 is rotated. Then, the impeller 130 fixed to the shaft portion 120 rotates in the water chamber 170 in the housing 160.
In this case, the cooling water filled in the water chamber 170 as a cooling medium for cooling the engine around the water chamber 170 is introduced to the external peripheral side of the impeller 130 by the centrifugal force in accordance with the rotation of the impeller 130. The differential pressure is generated between the rotational center of the impeller 130 and the external peripheral side in the water chamber 170. Thus, the cooling water is sucked from the intake port provided around the rotation center of the impeller 130 into the water pump. The, cooling water is pressurized to be sent to the external peripheral side of the impeller 130 by the rotation of the impeller 130 to be supplied to each portion to be cooled in the engine from the outlet portion (not shown) provided at the external peripheral side of the impeller 130. The engine is cooled down by the water circulation in the foregoing manner.
In this case, although one end of the pulley (i.e., left side of
According to the water pump of the second embodiment of the present invention, the opening 125 of the shaft portion 120 is closed with a closing portion 110d of the pulley 110. In case the pump 101 is assembled to the engine body provided in the engine compartment, the water droplet may be applied to the surface of the pump 101 due to the water splash during the vehicle driving. Even in this case, the opening 125 of the shaft portion 120 is securely closed by the closing portion 110d by fixing the shaft portion 120 to a recess portion 110g of the pulley 110 by press fitting. Thus, the invasion of the dump and the water droplet to the opening portion 125 can be securely prevented with a simple construction.
Normally, the inside of the shaft portion 120 formed by the press molding is unlikely to be successfully treated by the surface finishing and is apt to be eroded (e.g., rusted). With the water pump of the second embodiment, because the opening 125 is closed, the invasion of the water droplet from the outside can be prevented and the erosion in the shaft portion can be prevented. With this construction, the decline of the strength of the shaft portion 120 due to the rusting in the shaft portion and the water leakage due to the damage of the shaft portion 120 can be prevented and the fitting strength between the pulley 110 and the bearing 140 is increased to prevent the dropping out of the belt from the pulley 110.
Further, with the water pump of the second embodiment of the present invention, even when temporary leakage is generated in case the external object invades into the axial sealing member 150, the cooling water is introduced from the water chamber 170 to one end of the bearing 140 via the axial sealing member 150 and the external peripheral surface 120a of the shaft portion 120. Notwithstanding, because the opening 120f having a size slightly smaller than the size between the outer ring 140b of the bearing 140 and the internal diameter end portion 164c of the body 164 is formed on one axial end portion (i.e., flange portion) 120c of the shaft portion 120 in the pump 101, the cooling water leaked in the axial direction from the opening 120f is retained in a space 260 formed by an axial end portion 110h and the axial end portion 120c of the shaft portion 120.
Thus, the water pump of the second embodiment of the present invention includes a drain pocket function which is capable of retaining the small amount of leaked cooling water leaked from the water chamber 170 via the axial sealing member 150 in the space 126. By retaining the small amount of the leaked cooling water which is not recognized being leaked due to the defective of the sealing in the space 126, the leakage of the cooling water to the outside of the pump can be prevented. Thus, the reliability of the water pump is improved.
A third embodiment of the water pump according to the present invention will be explained referring to
With the pump 201 of the third embodiment, an inner ring 240a of a bearing 240 is press fitted to a body 264 fixed to the engine via a tightening member 265 such as bolt not to be relatively rotated. An outer ring 240b of the bearing 240 is press fitted to be fixed to a recess portion 221g formed on an external peripheral portion of the shaft portion 221 having a cylindrical axis in the center.
The shaft portion 221 having the cylindrical configuration in the center is formed by press molding. As shown in
Thus, when the pump 201 is assembled to the engine body provided in the engine compartment of the vehicle, even when the water droplet is applied to the surface of the pump 201 shown in
A fourth embodiment of the water pump according to the present invention will be explained referring to FIG. 5. With the water pump of the fourth embodiment, the basic construction is the same as the water pump according to the third embodiment. As shown in
A fifth embodiment of the water pump according to the present invention will be explained with reference to FIG. 6. The basic construction of the water pump of the fifth embodiment is the same with the water pump of the third embodiment shown in FIG. 4. Although the opening of the shaft portion 221 of
A sixth embodiment of the water pump of the present invention will be explained referring to
In the sixth embodiment, since the holes 526 are formed on the connecting portion 521c, it is able to form a straight portion 526a with a high degree of accuracy and it is able to increase the strength of the engagement between the nail portions 524c and the straight portion 526a. Further, since the nail portions 524c are disposed in the circumferential direction, the nail portions is not affected by a centrifugal force and the strength of the engagement between the nail portions 524c and the straight portion 526a can be improved.
A seventh embodiment of the water pump of the present invention will be explained referring to
In the seventh embodiment, since it is able to fix the cover 624 by fitting the projecting portion 624d into the opening 25a, it is able to simplify the work operation for assembling.
According to the embodiments of the present invention, because the opening the shaft portion is substantively closed by the cover or the closing portion of the rotational member, the invasion of the water droplet from the outside into the inside of the opening can be securely prevented. Thus, the water droplet is not retained at the opening portion of the shaft portion, which protects the shaft portion. Accordingly, the deterioration of the shaft portion due to the rusting, the perforation, the water leakage in the shaft portion can be securely prevented and the reliability of the water pump can be increased.
Although the embodiments are explained by applying the pump to the water pump for the vehicle, the invention is not limited to the foregoing embodiments and the pump can be applied to the output pump for outputting the fluid (e.g., operation fluid) to the outside in the hydraulic pressure device.
The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiment described herein is to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2002-045201 | Feb 2002 | JP | national |
| 2002-054039 | Feb 2002 | JP | national |
| 2003-044215 | Feb 2003 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2855909 | Stefan | Oct 1958 | A |
| 3838899 | Sampatacos | Oct 1974 | A |
| 4890946 | von Pragenau | Jan 1990 | A |
| 4955786 | Kunkel et al. | Sep 1990 | A |
| 4966572 | Kunkel et al. | Oct 1990 | A |
| 5026253 | Börger | Jun 1991 | A |
| 5125795 | Suzuki et al. | Jun 1992 | A |
| 5795137 | Ozawa et al. | Aug 1998 | A |
| 6561756 | Ozawa et al. | May 2003 | B2 |
| 6561770 | Okuda | May 2003 | B2 |
| 20020034438 | Ozawa et al. | Mar 2002 | A1 |
| Number | Date | Country |
|---|---|---|
| 0 289 958 | Nov 1988 | EP |
| 2-45698 | Feb 1990 | JP |
| 4-262096 | Sep 1992 | JP |
| 404250306 | Dec 1992 | JP |
| 11-336699 | Dec 1999 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20030175133 A1 | Sep 2003 | US |
