Note: Descriptions are shown in the official language in which they were submitted.
~03957~
The present invention relates to a pump unit for liquid cooled
internal combustion engines, preferably for a motor car engine. The pump in
accordance with the invention constitutes in mounted condition a unit in
which the components preferably are undetachably united together.
The conventional cooling water pumps are so designed, that they
consist of relatively large parts fastened together with screws and such
pumps are relatively heavy and space consuming.
According to one aspect of the invention, a pump unit for liquid-
cooled internal combustion engines comprises a bearing housing member, an
aperture formed therein; a rotatable assembly including an impeller disposed
adjacent one side of said housing member and rotatably supported by said
housing member and a drive member for rotating said impeller and including
a drive pully disposed adjacent the other side of said housing member, said
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assembly including a connecting portion extending through said aperture and
connecting said impeller to said drive member; bearing means supporting the
drive member for rotation relative to the housing member; and a seal adapted
to seal said aperture between said rotatable assembly and said housing
member wherein the axial length L of the pump unit as measured from ~he
impeller to the oppositely located end of the drive member and the pitch `
diameter Dm of the bearing means are related mathematically by the expres-
sion
L ~f~ ~ Dm ~ L/~
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~39573
The advantages of fluid pumps in accordance with the present
invention are the following: It is possible to select various materials for
this shaftless type of pump. Suitable materials might be aluminum, plastics
or pressed metal sheet. In selecting a suitable material, the pump will be
cheap and light and has in relationship to the small weight, a good struc-
tural strength. The good reliability in operation depends on the fact that
there will be less unbalance and smaller masses in the pump components. An
important feature of the pump unit of the present invention is its compact
design. To this end, since there is no conventional shaft, the bearing of
one embodiment of the pump unit is selected with greater pitch diameter and
of about the same order of magnitude as the axial length of the pump unit
measured from the impeller to the oppositely located end of the drive member.
Such a bearing, preferably of single row deep groove type, or in some cases
of double row angular contact type, is simpler and axially more compact. i
Additionally, the axial length of one embodiment of the pump unit measured ~ ~`
from the impeller to the outer end of drive member and the outer diameter of
the impeller are of the same order of magnitude to provide a compact pump
unit. Further, the axial length of the pump unit is of about the same or at
most, equal to the diameter of the impeller. A further advantage is the
possibility of getting a good sealing effect since the sealing diameter is ;~
very small. The pump unit is so designed that a good ventilating and drying
of the bearing is obtained in front of, or behind the same, so that possible
fluid particles will not get into contact with the bearing. Regarding an ~ ;
outer-ring-rotated bearing, it is possible to place the seal with its small
diameter essentially
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~L039573 `
in the radial center line of the bearing, whereby a considerable increase in
the life of the seal is obtained.
The invention will now be described with reference to the accompanying
drawings in which: Figure 1 shows an embodlment of the pump unit with a
specially shaped inner-ring-rotated bearing;
Figure 2 shows a modification of the pump unit with an outer-ring-
rotated bearing;
Figure 3 is a sectional view of still another embodiment of pump
unit in accordance with the present invention; and
Figure 4 is a sectional view of a modified form of the pump unit
shown in Figure 3.
Referring now to the drawings and particularly to Figure 1 thereof,
there is illustrated a pump unit constructed in accordance ~nth the present
invention~ the main components of which include a pump unit bearing housing
1~ a bearing 2~ a drive member 3, a rotor or impeller 4~ and a sealing
element 5. In the assembly illustrated, the pump unit housing 1 is detachably
mounted by suitable means such as screws to the pump housing ~ to support
the pump unit assembly in an opening in the pump housing, which may be a
conventional volute casing. It is noted that the pump unit may be secured
to the pump housing by other means; for example, by a press fit or be formed
integrally therewith.
Figure 1 shows a cooling water pump in which the pump lmit bearing
housing 1 consists of a relatively thin wall 6 of pressed sheet metal~ die~
casted aluminum or plastics which is fixed to a stronger housing portion 7
suitably of aluminum. In the portion 7, the outer ring 8 of the bearing 2 is
fitted by shrinkage fit or otherwise. The inner and of the drive member 3 is
of a stepped configuration to define the inner raceway 9 of the bearing and
an axially extending seat 13 of smaller diameter than the raceway 9 for the
seal S. As illustrated, a space or p~cket for the seal is provided between
~L039S73
the wall 6 of the pump unit housing 1 and the radial leg 30 of the drive
member 3 connecting the raceway 9 and seal 13. The rotor 4 is mounted on the
radial extension 32 depending from seat 13 by suitable means; for instance~
by welding or riveting. The inner raceway 9 is in the embodiment shown
integrated with the drive member 3 of the pump unit, but the raceway might
also be shaped in a separate inner ring fitted on the drive member 3 In
the embodiment shown, the rolling bodies of the bearing consist of balls and
the bearing is provided with a cage 10 of a suitable type. As shown in the
figure, the inner ring will be rotated.
The pump unit is in this case driven by a belt from a suitable
source of power. For this purpose the drive pulley part 11 of the drive
member 3 is profiled on its outer surface as shown at 12. In the embodiment
illustrated, the bearing is a single row deep groove ball bearing and the
seal 5 is mounted radially inwardly of the pitch circle of the bearing.
Further, in accordance with the present invention, the axial length L of the
pump unit measured from the rotor 4 to the outer end of the drive member 3
and the pitch diameter Dm of the bearing are preferably of the same order of
magnitude. Additionally, the axial length L of the pump unit and the outer
diameter D of the rotor 4 are preferably of the same order of magnitude.
~urther, the axial le~gth L of the pwmp unit may be approximately equal to,
or at most, equal to the diameter D of the rotor 4. This arrangement pro-
vides a very compact pump unit and facilitates the use of a comparatively
simple type of bearing such as the single row deep groove ball bearing
illustrated. Further, by this construction, the seal can be located in close
proximity to the bearing and will be insensitive to any possible wobbling or
warping, and thus have an extended life. Seal failure is one of the more
common failures in the water pumps in the automotive field. Additionally,
a compact pump unit design offers greater freedom in selection of materials
so that the pump unit may be made very economically and of light weight
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construction. ~o39~73
The various components of the pump unit provide a shaftless assembly
wherein the various elements such as the bearing, d~ive member, impeller and
pump unit housing preferably form an integral unit which is easily replace-
able in the event of pump failure.
In new installations, the separable integral pump unit of the
present invention is adapted for use with various pump housing designs thereby
providing a standard unit which may be assembled to a plurality of different
designed pump housing and therefore has a non-obsolescent characteristicO
Presently, as engine designs are changed, it often necessitates a correspond-
ing design change in the entire water pump assembly.
In the pump unit housing 1 tnere is provided a number of large
openings 14 intended for ventilating, drying and draining purposes. Through
these openings there is obtained a very effective ventilating or draining in
front of the bearing. Close to the drive side of the pump there can be
applied a fan (not shown here). This can be designed in such a way that the
fan is integrated with the drive member of the pump so that a combined fan
and drive member is obtained. The fan can, of course, be a separate part
fixed to the drive member. ~
In Figure 2 a modiication of the cooling water pump unit is shown --
in which, unlike the above mentioned embodiment, the outer ring of the bearing
rotates. The parts of the pump unit which are similar to the previously de- ;
scribed embodiment are referenced by the same numerals with the letter "a"
postscript. In this example a conventional bearing is used, for example, a
single row deep groove ball bearing, the inner ring 15 of which is fitted on
an annular part 16 of the pump unit bearing housing la. The outer ring 17 of
the bearing is fitted into a bearing seat 18 in the drive member 3a. The
outer surface of the drive pulley part of the drive member is profiled at 19
as in the first embodiment. The drive member is provided with a web portion
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20 which i5 fixed to a hub portion 21 of the impeller~ by~ for example~ weld-
ing. The seal 5a is fitted to a suitable place on the portion 21 in connection
with the inner part of the pump unit housing 1~. The seal can also be located
in the radial center line of the bearing whereby angular warpings are elimin-
ated. The drive member is also in this embodimant provided with large drain-
ing/ventilating openings 22.
In the present instance, the axial length L of the pump unit assembly
measured from the rotor 4a to the outer end of the drive member 3a, and the
pitch diameter D of the bearing are preferably of the same order of magnitude.
10 Additionally, the axial length L of the pump unit and the outer diameter D i
of the rotor 4 are preferably of the same order of magnitude. Further, the ~ ~-
axial length L of the pump unit may be approximately equal to, or at most,
equal to the diameter Dr of the rotor 4. These relationships provide the
functional advantages set forth above in connection with the previously de-
scribed embodiment. Further, as illustrated, the seal 5a is located closely
adjacent the bearing assembly and disposed radially inwardly thereof. To
this end, the housing la is provided with an annular recess defining two walls
of a pocket for the seal at the juncture of the radial portion 24 of the
housing la and the annular part 16. The other walls of the p~-cket, as illus- ;
trated, are defined by the rear face of the impeller and the hub portion 21.
Figure 3 shows another embodiment of pump unit in accordance with ~-
the present invention. The elements of the pump unit similar to those of the
previously described embodiment, are designated by the same numerals with
the letter "b" postscript. Thus the pump unit comprises a pump unit housing
lb adapted to be secured by suitable means to the main pump housing H , for
example, in the manner described previously, a rotor or impeller 4b, one end
of which is disposed interiorly of the pump housing H and is secured to a
drive member 3b, which in the present instance has a sheave or pulley formed
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~039573
integrally therewith for a belt connected to a suitable drive means to rotate
the impeller. The drive member 3b mo~mts at its o~lter and remote from the
pump unit housing lb, a fan wheel 29 connected at its hub portion 31 in a
suitable manner, for example, by screws 34. The bearing 2b in the present
instance, is illustrated as a single row deep groove ball bearing comprising
an outer ring 17b fitted in the drive member 3b, an inner ring 15b fitted in
the pump unit housing lb and a plurality of balls in the annular space between
the rings. However, when a fan wheel 29 is provided, a double row angular
contact ball bearing is preferred. The drive member is also provided, in -
the present instance~ with draining/ventilati~g openings 22b.
In accordance with this embodiment, the axial length L of the pump
unit measured from the rotor 4b to the outer end of the drive member 3b and
the pitch diameter D of the bearing are preferably of the same order of
magnitude. Additionally, the axial length L of the pump unit and the outer
diameter D of the rotor 4 are preferably of the same order of magnitude.
Further, the axial length ~ of the pump unit may be approximately equal to~ -
or at most, equal to the diameter D of the rotor 4. These relationships
provide the functional advantages set forth above in connection with the
previously described embodiments. Further as illustrated, the seal 5b is
located closely adjacent the bearing assembly and disposed radially inwardly
thereof. To this end, the pump unit housing lb is provided with a circumfer-
entially extending flange portion 40b, the outer surface of which defines the
seat for the inner ring 15b and which defines interiorly thereof, a pair of
pockets separated by a thin web 4~b. The outer pocket 44b is outwardly flared
to receive the central hub portion 46b of the drive member 3b which is pro~
vided with an opening within which the stub shaft 49b of the impeller is ~-
mounted by a locking key 53b. The inner pocket 47b is outwardly flared in
an opposite direction and mounts therein the seal 5b.
There is illustrated in Figure 4 a modified form of a pump unit ;
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~039573
constructed in accordance with the present invention. The pump unit is
similar to the embodiment of Figure 3 and accordingly~ the basic elements
thereof are designated with the same numera:Ls and a letter ~c~ postscript.
Thus, the pump unit includes a pump unit bearing housing lc, a bearing 2c,
drive member 3c, an impeller 4c, and a sealing element Sc. In accordance
with this embodiment of the invention, the seal Sc which circumscribes the
shaft 49c of the impeller, is located close~Ly adjacent the bearing 2c, and
is disposed in the radial center line C of the bearing. By this arrangement
the seal is insensiti~e to any possible wobbling or warping and provides an
optimum extended seal life potential. To accomodate the seal 5c in this
location, there is provided an annular pocket defined in part by the inner
circumferentially extending wall 41c of the Plange portion 40c, a radial
shoulder 43c of the flange portion 40c, and a circumferential shoulder 45c
aligned with the shoulder 43c at the juncture of the hub 47c of the impeller ;
4c and the stub shaft 49c. A snap ring 51c seats the seal 5c in the pocket.
As illustrated, the shaft 49c is suitably mounted in the opening in the
drive member by a locking key 53c.
In the present instance, the axial length L of the pump unit
assembly measured from the rotor 4c to the outer end of the drive member 3c
and the pitch diameter Dm of the bearing are preferably of about the same
order of magnitude. Additionally, the axial length L of the pump unit and
the outer diameter D of the rotor 4 are preferably of the same order of
magnitude. Further, the axial length L of the pump unit may be approximately
equal to, or at most~ equal to the diameter Dr of the rotor 4. These re
lationships provide the functional advantages set forth above in connection
with the previously described embodiments.
The term "order of magnitude" as used herein is defined by the `~
following mathematical definition. Two quantities A and B are of the same
"order of magnitude" if a ~3~ B~ A/ ~ . For example~ if B is 1 in., and A is
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IL~)3~3tS73
between 1.732 in. and 0.577 in., then A and B are of the same order of
magnitude. Thus the axial length L of the pump unit and the pitch diameter
D of the bearing are of about the same order of magnitude if D ~ ~ L
Dm~/ ~
The axial length L of the pump unit and the outer diameter of the
impeller are of about the same order of magnitude if D ~ 3 ~ L ~ D ~ ~3.
_ 9 ~
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