U.S. patent application number 10/829369 was filed with the patent office on 2004-10-28 for water pump.
This patent application is currently assigned to Aisin Seiki Kabushiki Kaisha. Invention is credited to Hashiguchi, Itsuro, Hattori, Takumi, Katsumata, Akihiro, Koga, Yojiro, Ozawa, Yasuo.
Application Number | 20040213683 10/829369 |
Document ID | / |
Family ID | 32959635 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040213683 |
Kind Code |
A1 |
Koga, Yojiro ; et
al. |
October 28, 2004 |
Water pump
Abstract
A water pump includes a driven portion, a shaft including a
hollow portion for rotating with the driven portion as a unit, an
impeller rotating with the shaft as a unit, a body including a
cylindrical supporting portion inserted by the shaft, a bearing
provided between an external peripheral surface of the supporting
portion and an internal peripheral surface of the driven portion
for rotatably supporting the driven portion, and a mechanical seal
sealing one side of a cylindrical space defined between an external
peripheral surface of the shaft and an internal peripheral surface
of the supporting portion, wherein a vibration absorption member is
provided in the hollow portion of the shaft.
Inventors: |
Koga, Yojiro; (Kariya-shi,
JP) ; Katsumata, Akihiro; (Handa-shi, JP) ;
Hashiguchi, Itsuro; (Chiryu-shi, JP) ; Hattori,
Takumi; (Chiryu-shi, JP) ; Ozawa, Yasuo;
(Kariya-shi, JP) |
Correspondence
Address: |
REED SMITH LLP
Suite 1400
3110 Fairview Park Drive
Falls Church
VA
22042
US
|
Assignee: |
Aisin Seiki Kabushiki
Kaisha
|
Family ID: |
32959635 |
Appl. No.: |
10/829369 |
Filed: |
April 22, 2004 |
Current U.S.
Class: |
417/363 ;
415/111 |
Current CPC
Class: |
F04D 29/043 20130101;
F04D 29/669 20130101; F01P 5/10 20130101 |
Class at
Publication: |
417/363 ;
415/111 |
International
Class: |
F04B 017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 23, 2003 |
JP |
2003-118747 |
Claims
What we claim is:
1. A water pump comprising: a driven portion; a shaft including a
hollow portion for rotating with the driven portion as a unit; an
impeller rotating with the shaft as a unit; a body including a
cylindrical supporting portion inserted by the shaft; a bearing
provided between an external peripheral surface of the supporting
portion and an internal peripheral surface of the driven portion
for rotatably supporting the driven portion; and a mechanical seal
sealing one side of a cylindrical space defined between an external
peripheral surface of the shaft and an internal peripheral surface
of the supporting portion; wherein a vibration absorption member is
disposed in the hollow portion of the shaft.
2. A water pump according to claim 1, wherein the vibration
absorption member is made of an elastic material.
3. A water pump according to claim 1, wherein the vibration
absorption member includes pores in its body.
4. A water pump according to claim 1, wherein the vibration
absorption member having a predetermined size is pushed to place it
into the hollow portion of the shaft from an opening portion
thereof.
5. A water pump according to claim 2, wherein the vibration
absorption member is formed by injection molding of softened
elastic material into the hollow portion of the shaft from an
opening portion thereof.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority under 35
U.S.C. .sctn. 119 with respect to a Japanese Patent Application
2003-11-8747, filed on Apr. 23, 2003, the, entire content of which
is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention generally relates to a water pump. More
particularly, the present invention pertains to a water pump used
for a vehicle.
BACKGROUND OF THE INVENTION
[0003] A known example of a water pump, disclosed in the U.S. Pat.
No. 6,561,756, includes a pulley, a shaft including a hollow
portion for rotating with the pulley as a unit, an impeller
rotating with the shaft as a unit, a body including a supporting
portion formed to cylindrical shape inserted by the shaft, a
bearing provided between an external peripheral surface of the
supporting portion and an internal peripheral surface of the pulley
for rotatably supporting the pulley, and a mechanical seal sealing
one side of a cylindrical space defined between an external
peripheral surface of the shaft and an internal peripheral surface
of the supporting portion.
[0004] In this composition, the mechanical seal of the water pump
seals up cooling fluid in a fluid chamber and makes the fluid
chamber and external separate. The mechanical seal having a
rotation side member and a fixed side member. These members are
relatively rotatably mounted each other keeping a fluid tight
manner. According to this structure, the cooling fluid plays a
lubrication role, and the cooling fluid comes into between sliding
surface of each the rotational side member and the fixed side
member. If the sliding surface is formed to be smooth surface,
sealing property thereof becomes to be improved, although
lubricating property thereof becomes to be deteriorated. In this
condition, the mechanical seal generates stick slip phenomenon and
tends to be took place at the mechanical seal in which the
mechanical seal rotates with vibrating. The vibration generated at
the mechanical seal tends to be transmitted to the shaft and the
pulley to cause noise.
SUMMARY OF THE INVENTION
[0005] In light of foregoing, according to an aspect of the present
invention, a water pump includes a driven portion, a shaft
including a hollow portion for rotating with the driven portion as
a unit, an impeller rotating with the shaft as a unit, a body
including a cylindrical supporting portion inserted by the shaft a
bearing provided between an external peripheral surface of the
supporting portion and an internal peripheral surface of the driven
portion for rotatably supporting the driven portion, and a
mechanical seal sealing one side of a cylindrical space defined
between an external peripheral surface of the shaft and an internal
peripheral surface of the supporting portion, wherein a vibration
absorption member is disposed in the hollow portion of the
shaft.
[0006] It is a primary object of the present invention is to
prevent a noise from generating at the mechanical seal arranged
between the rotational side member and the fixed side member.
[0007] It is another object of the present invention is to prevent
a vibration from generating at the mechanical seal arranged between
the rotational side member and the fixed side member.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0008] 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 wherein:
[0009] FIG. 1 is a cross-sectional view of a water pump according
to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0010] A preferred embodiment of the present invention will be
described hereinbelow in detail with reference to the accompanying
drawings.
[0011] FIG. 1 is a cross-sectional view of a water pump 10
according to an embodiment. A body 12 of the water pump 10 is
rigidly attached to an engine cylinder block 90 (or timing chain
case and so on) using a fastening means 13 via a gasket 80 and so
on. On the body 12, a cylindrical portion (supporting portion) is
formed with stepwise diameter provided with a large diameter
portion 12a and a small diameter portion 12b at right side and left
side of FIG. 1, respectively. The large diameter portion is formed
to have larger diameter than the small diameter portion. An inner
race of a bearing 14 is fitted to be fixed to an external
peripheral surface of the small diameter portion of the cylindrical
portion. In addition, right side face of the inner race of the
bearing 14 is adjacently placed to the large diameter portion 12a
of the body 12. An interstice may be formed between the right side
of the inner race and the large diameter portion 12a.
[0012] On an outer race of the bearing 14, a pulley 20 (driven
portion) is rotatably attached as a unit. The pulley 20 is formed
as an external peripheral portion of a rotational body 18 which has
a cylindrical cup shape. To discharge fluid droplet got out from a
mechanical seal 50, an opening portion 22a is formed at a bottom
portion 22 of the rotational body 18 neighboring the external
peripheral portion of the pulley 20 with equally angle. A shaft 25
is integrally disposed at the center of the bottom portion 22 of
the rotational body 18 so as to be elongated in the direction to
draw apart from the bottom portion 22 (right direction in FIG. 1),
and a pulley 20 side end of the shaft 25 is opened. At an end point
of the shaft 25, bottom wall portion is formed to occlude there.
The rotational body 18, integrally including the pulley 20, bottom
portion 22 and shaft 25, are formed by pressing of plate material
(such as a steel plate) to have same axis. Then, the pulley 20,
bottom portion 22 and shaft 25 are plated or coated to give
corrosion resistance.
[0013] An impeller 30 is rotatably provided at the occluded end
point of the shaft 25. The impeller 30 includes a base portion 30a,
a fin 30b formed to project from a rim portion of the base portion
30a and a hollow convex portion 30c projecting from the center
portion of the base portion 30a to right direction in FIG. 1 as a
unit. By fitting and attaching the hollow convex portion 30c to end
point of the shaft 25, the shaft 25 and the impeller 30 are rotated
integrally. By the way, the impeller 30 may be treated to give
corrosion resistance after press forming of a plate material. In
addition the impeller 30 may be formed by resin material. The
impeller 30 is disposed within the fluid chamber 95 which is formed
in the engine cylinder block 90 and so on and of which an opening
portion is occluded by the body 12. The fluid chamber 95 is a
component of an engine cooling fluid circuit (not shown).
[0014] The mechanical seal 50 is provided at one side of a
cylindrical space 27 (a boundary to the fluid chamber 95) defined
between the external peripheral portion of the shaft 25 and
internal peripheral portion of the large diameter portion 12a and
the small diameter portion 12b of the body 12. To prevent getting
out of cooling fluid to outside, the mechanical seal 50 isolates
the fluid chamber 95 from outside in watertight condition. The
mechanical seal 50 is made up of a fixed ring 50a rigidly attached
to internal peripheral side of the large diameter portion 12a of
the body 12 and a rotational ring 50b rigidly attached to the shaft
25 with contacting to the fixed ring 50a. The fixed ring 50a and
the rotational ring 50b relatively rotate with contacting each
other to keep watertight condition.
[0015] A hollow portion 25a is formed at inferior side of the shaft
25. In the hollow portion 25a, a vibration absorption member 26 is
provided. The vibration absorption member 26 is made of an elastic
material, and formed by pushing of the elastic material having a
predetermined size into the hollow portion 25a of the shaft from an
opening portion thereof. The vibration absorption member may be
formed by injection molding of softened elastic material into the
hollow portion of the shaft from an opening portion thereof. The
vibration absorption member 26 may be formed to have arbitrary
length. In addition, the vibration absorption member 26 may have
pores in its body. In addition, the vibration absorption member 26
may be made of rubber or polymer foam as an example of the elastic
material.
[0016] Next, operation and function of the embodiment will be
explained hereinafter.
[0017] The pulley 20 is rotated by a rotational force transmitted
from an output of an engine (not shown) via a belt 85 engaged to a
belt engaging face 20b of the pulley 20. With rotation of the
pulley 20, the shaft 25 attached to the pulley 20 as a unit is also
cooperatively rotated in the same direction. Then, the impeller 30
integrally attached to the shaft 25 is rotated in the fluid chamber
95 occluded by the body 12.
[0018] As the cooling fluid is filled in the fluid chamber 95, the
impeller 30 pushes the cooling fluid presented near the center of
the fluid chamber 95 in outer direction of the impeller 30
according to centrifugal force generated by rotation of the
impeller 30. Pumping action is conducted by centrifugal force from
the center of the impeller 30 to outer side. Accordingly, a
pressure difference between the rotational center of the impeller
30 and the outer side is took place in the fluid chamber 95, and
then, the cooling, fluid is sucked into the fluid chamber 95 from a
port 95a which is disposed close to the rotational center of the
impeller 30. Then, the cooling fluid is pushed to outer side by
pumping action of the impeller 30, and delivered to each cooled
portion in the engine from a discharge opening (not shown). In this
manner, the cooling fluid is circulated.
[0019] In this situation, for the mechanical seal 50, the fixed
ring (fixed side member) 50a and the rotational ring (rotational
side member) 50b slide each other. At this time, the cooling fluid
plays a lubrication role for the cooling fluid comes into the
sliding portion in which the sliding surfaces of the fixed ring 50a
and the rotational ring 50b slide each other. If the sliding
surface is formed to be smooth surface, sealing property thereof
becomes to be improved, although lubricating property thereof
becomes to be deteriorated. In this condition, the mechanical seal
50 generates stick slip phenomenon and rotates with vibrating. The
vibration generated at the mechanical seal 50 tends to be
transmitted to the shaft 25 and the pulley 20 to cause noise.
[0020] Although, for the embodiment of the present invention, the
vibration generated at the mechanical seal 50 may be absorbed by
the vibration absorption member 26 provided in the hollow portion
25a. Thus, transmission of the vibration to the shaft 25 and the
pulley 20 becomes low, and noise generation may be prevented.
[0021] The principles, a 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
embodiment 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.
* * * * *