U.S. patent application number 13/010946 was filed with the patent office on 2011-07-28 for apparatus for a pump, and a water pump.
This patent application is currently assigned to LICOS Trucktec GmbH. Invention is credited to Rainer Krafft, Andreas Wolf.
Application Number | 20110182757 13/010946 |
Document ID | / |
Family ID | 43778465 |
Filed Date | 2011-07-28 |
United States Patent
Application |
20110182757 |
Kind Code |
A1 |
Wolf; Andreas ; et
al. |
July 28, 2011 |
APPARATUS FOR A PUMP, AND A WATER PUMP
Abstract
An apparatus is proposed for a pump, in particular a water pump
of a motor vehicle having a rotating pump wheel which can be
driven, and having a switchable clutch arrangement for switchable
connection of the pump wheel to a drive side. According to the
invention, the pump wheel is mounted such that it can rotate on a
rotatable driveshaft.
Inventors: |
Wolf; Andreas; (Tettnang,
DE) ; Krafft; Rainer; (Heiligenberg, DE) |
Assignee: |
LICOS Trucktec GmbH
Markdorf
DE
|
Family ID: |
43778465 |
Appl. No.: |
13/010946 |
Filed: |
January 21, 2011 |
Current U.S.
Class: |
417/374 |
Current CPC
Class: |
F04D 13/026 20130101;
F04D 15/0027 20130101; F04D 13/027 20130101; F01P 5/12 20130101;
F04D 29/20 20130101 |
Class at
Publication: |
417/374 |
International
Class: |
F04B 9/02 20060101
F04B009/02; F01P 5/12 20060101 F01P005/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 26, 2010 |
DE |
10 2010 005 936.6 |
Claims
1. An apparatus for a pump of a motor vehicle, in particular a
water pump having a rotating pump wheel which can be driven, and
having a switchable clutch arrangement for switchable connection of
the pump wheel to a drive side, wherein the pump wheel is mounted
such that it can rotate on a rotatable driveshaft.
2. An apparatus according to claim 1, wherein the pump wheel is
arranged on the driveshaft such that it can move axially.
3. An apparatus according to claim 1, wherein an electromagnetic
coil is provided, and acts on a magnetically permeable armature
element when current is flowing.
4. An apparatus according to claim 3, wherein the armature element
can be moved axially by a magnetic influence of the coil, wherein
the switching state of the pump wheel can be predetermined by a
selected axial position of the armature element.
5. An apparatus according to claim 1, wherein contact means are
arranged on the driveshaft such that they rotate together, and are
designed for a force fit and/or an interlock with a contact section
on the pump wheel which can rotate on the driveshaft.
6. An apparatus according to claim 3, wherein the armature element
and the contact means are matched to one another such that a force
fit and/or an interlock can be predetermined between the driveshaft
and the pump wheel, as a function of an axial position of the
armature element.
7. An apparatus according to claim 1, wherein a displacement member
is provided, by means of which a contact section on the pump wheel
can be made to interlock and/or have a friction fit with the
contact means.
8. An apparatus according to claim 3, wherein the armature element
is arranged on a spring element which is connected to the
driveshaft such that they rotate together, wherein the spring
element is designed to press axially on the pump wheel.
9. An apparatus according to claim 3, wherein the armature element
is arranged on the pump wheel.
10. An apparatus according to claim 1, wherein an axially acting
bearing stop is formed on the driveshaft for the pump wheel.
11. An apparatus according to claim 5, wherein the contact means on
the driveshaft comprise a friction means in the form of a wedge
element which can make a friction fit with a friction section on
the pump wheel.
12. A pump for a motor vehicle, in particular a water pump having
an apparatus according to claim 1.
Description
[0001] This application claims the benefit under 35 USC
.sctn.119(a)-(d) of German Application No. 10 2010 005 936.6 filed
Jan. 26, 2010, the entirety of which is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The invention relates to an apparatus for a pump, in
particular a water pump of a motor vehicle, and a water pump.
BACKGROUND OF THE INVENTION
[0003] European Patent Application Publication No. 2 105 624 A1
discloses a clutch, which can be operated electromagnetically, for
a water pump in the cooling water circuit of an internal combustion
engine having a drive wheel which can be mounted such that it can
rotate in the area of or on the water pump, and having an armature
disk which interacts with a coil. The clutch is designed to create
a so-called "fail safe" arrangement, in which a water pump can be
driven via the clutch even when no current is flowing in the coil,
for example, if the electrical voltage supply fails.
SUMMARY OF THE INVENTION
[0004] The invention is based on the object of providing an
apparatus for a pump, in particular a water pump, in a motor
vehicle having a clutch arrangement, thus resulting in a switchable
pump of compact design.
[0005] The invention is based on an apparatus for a pump in a motor
vehicle, in particular a water pump, for example for the cooling
water circuit of an internal combustion engine. The pump comprises
a rotating pump wheel which can be driven, and a switchable clutch
arrangement for switchable connection of the pump wheel to a drive
side. The essence of the invention is now that the pump wheel is
mounted such that it can rotate on a rotatable driveshaft, such
that a relative movement can take place between the pump wheel and
the driveshaft. The pump wheel can therefore rotate on the
driveshaft. This measure makes it possible to integrate a clutch
arrangement at least partially in a simple manner in a pump, in
particular within a pump housing. Roller bearings or journal
bearings can be used to bear the pump wheel on the driveshaft. A
low-cost journal bearing is preferably used, since the operating
time in which the pump wheel is at a considerably lower rotation
speed than the driveshaft as a result of an appropriately switched
clutch is short in comparison to the total usage time. Any
increased wear which occurs to a journal bearing, in comparison to
a roller bearing, can therefore be coped with.
[0006] When the clutch is engaged, the pump wheel preferably
rotates at the same speed as the driveshaft, or at least
approximately at the same speed as the driveshaft. However,
ideally, there is no slip between the driveshaft and the pump
wheel. In the disengaged state, there is at least a relative
rotation speed between the pump wheel and a driveshaft which
rotates as before. The pump wheel is preferably stationary, or is
in a state with a low drag rotation speed, as a result of friction
forces which occur as before.
[0007] In order to, produce a disengaged or engaged state of the
pump wheel, it is furthermore proposed that the pump wheel be
movable axially on the driveshaft. It is therefore feasible for a
friction section of the pump wheel to interact with friction means
by axial movement, which friction means are arranged on the
driveshaft such that they rotate together.
[0008] In order to produce switching states of the clutch
arrangement, it is furthermore proposed that an electromagnetic
coil be provided, and act on a magnetically permeable armature
element when current is flowing. An armature element is
advantageously arranged within a pump housing. The electromagnetic
coil can likewise be arranged within the pump housing, for a
compact and low-cost design. However, an arrangement outside the
pump housing is also feasible, and has advantages in terms of an
electrical supply to the coil.
[0009] It is also preferable for the armature element to be movable
axially by an electromagnetic influence of the coil, wherein the
switching state of the pump wheel can be predetermined by a
selected axial position of the armature element. By way of example,
this allows the pump wheel to move axially or the armature element
to move a further element which acts on the pump wheel in order to
produce a switching state.
[0010] In order to transmit a torque from the driveshaft to the
pump wheel, a further preferred refinement of the invention
proposes that contact means, in particular friction means, are
arranged on the driveshaft such that they rotate together, and are
designed for a force fit and/or an interlock, in particular a force
fit, with a friction section on the pump wheel which can rotate on
the driveshaft.
[0011] In this context, it is also preferable if the armature
element and the friction means are matched to one another such that
a friction fit is created between the driveshaft and the pump
wheel, as a function of an axial position of the armature
element.
[0012] One particularly preferred refinement of the invention
proposes a displacement member, by means of which a contact
section, for example a friction section of the pump wheel, makes a
friction contact with the friction means. The displacement member,
for example a spring, and in particular a compression spring,
preferably acts in the axial direction on the pump wheel when no
current is flowing through the electromagnetic coil, as a result of
which a friction section of the pump wheel is displaced against
friction means which are connected to the driveshaft such that they
rotate together. This results in a "fail safe" arrangement which
ensures that the pump wheel rotates even when the voltage supply
for the electromagnetic coil fails on a running internal combustion
engine with a rotating driveshaft. Particularly when the pump is
used in a cooling water circuit of an internal combustion engine,
this makes it possible to ensure high operational reliability.
[0013] It is also advantageous if the armature element is arranged
on a spring element which is connected to the driveshaft such that
they rotate together, wherein the spring element is designed to
exert an axial pressure effect on the pump wheel. This likewise
makes it possible to create a friction fit between a friction
means, which is arranged on the spring element, and a corresponding
friction section on the pump wheel when no current is flowing
through the electromagnetic coil, and there is therefore no force
acting on the armature element, thus creating a "fail safe"
arrangement. For example, when current is flowing in the coil, the
armature element can be moved axially such that friction means
which press in a sprung manner against the pump wheel are lifted
off it, thus allowing the pump wheel to rotate freely or
essentially freely on the driveshaft.
[0014] In a further preferred embodiment, it is advantageous for
the armature element to be arranged on the pump wheel. The armature
element can be fitted on the induction side or on the side of the
pump wheel remote from the induction side.
[0015] When no current is flowing through the electric coil, a
displacement member, in particular a spring element, allows the
pump wheel to be displaced to an engaged state.
[0016] Furthermore, for defined positioning of the pump wheel, it
is preferable for an axial bearing stop to be formed on the
driveshaft for the pump wheel. The bearing stop preferably acts as
a rotating bearing, thus allowing to rotate essentially freely in a
situation in which the pump wheel is pressing against the bearing
stop with an axial pressure force and, furthermore, for example,
the friction means are not producing any further friction
forces.
[0017] In one preferred embodiment, the friction means on the
driveshaft comprise a wedge element which can make a friction fit
with a friction section on the pump wheel. This allows the pump
wheel to be made to rotate at the same speed as the driveshaft with
a comparatively small axial displacement force, by means of a
"wedge drive effect" of a friction surface in the form of a wedge,
by means of a friction fit.
[0018] The apparatus according to the invention is preferably used
for pumps in a motor vehicle, in particular water pumps. In the
case of internal combustion engines, the preferred application is
the water pump for the water cooling circuit. A switchable cooling
water pump allows the engine to be raised to the operating
temperature more quickly when it is being started up from the cold
state. For this purpose, in this phase of engine operation, the
cooling water circuit is switched off by disengaging the pump
wheel. As soon as the engine is then at a predetermined operating
temperature, the pump wheel is engaged, as a result of which the
cooling water circuit starts to run.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A plurality of exemplary embodiments of the invention are
illustrated in the figures and will be explained in more detail in
the following text, indicating further advantages and details.
[0020] FIG. 1 shows a schematic illustration of a partially
sectioned side view of parts of a cooling water pump with a clutch
arrangement, and
[0021] FIGS. 2 and 3 show a corresponding illustration of two
further embodiments for comparable parts.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 shows elements of a cooling water pump with a clutch
arrangement within a pump housing, which is not illustrated. The
cooling water pump comprises a pump shaft 1 on which a pump wheel 2
is borne such that it can rotate via a sliding bush 3 which extends
axially and radially. The radial section 3a of the sliding bush 3
can rest on a radial bearing stop 4, for example in the form of a
steel disk. A sliding ring seal or a similar seal can also
preferably be integrated in the bearing stop. The pump wheel 2 is
preferably in the form of an impeller, as is illustrated in FIG. 1,
which is surrounded by an appropriately shaped housing (not
illustrated).
[0023] A compression spring 5 is mounted on the driveshaft such
that they rotate together and has an engagement section 6 which can
interact in an interlocking and/or force-fitting manner with the
pump wheel 2. In the present case, a groove 2a in the form of a V
or wedge is incorporated in an annular shape into the pump wheel 2,
and an engagement section 6 enters this groove 2a in order to
produce a friction fit between the appropriately matched engagement
section 6 and the groove 2a.
[0024] However, it is also feasible for the engagement section 6 to
have shaped elements which fit corresponding shaped elements in the
V-shaped groove 2a, thus resulting in an interlock in the engaged
state.
[0025] A magnetically permeable armature element 7, for example an
annular element which interacts with an electromagnet 8, is fitted
to the engagement section 6. The electromagnet 8 may be fitted
inside or outside the pump housing. If arranged outside the pump
housing, a magnetic circuit must be ensured through the pump
housing to the armature element 7, in order to allow a magnetic
force to act on the armature element 7 when current flows through
the electromagnet 8.
[0026] Stop elements, for example in the form of finger-like stop
elements, are preferably provided to limit the movement of the
compression spring 5 on which the engagement section 6 and the
armature element 7 are arranged, which stop elements axially limit
axial movement of the armature element 7 when an attraction force
is applied by the electromagnet 8.
[0027] A water pump arrangement as shown in FIG. 1 operates as
follows:
[0028] Because the engagement section is pressed against the pump
wheel 2 when no current is flowing through the electromagnet 8,
this results in a "fail safe" arrangement, in which the pump wheel
runs at the same rotation speed as the pump shaft 1 when no current
is flowing, because of the friction effect of the engagement
section 6.
[0029] In order to "disengage" the pump wheel, a voltage is applied
to the electromagnet and can be increased in an initial time
interval in order to draw the armature element against the
electromagnet 8. This releases the friction fit between the
engagement section 6 and the wedge-shaped groove 2, and the pump
wheel is borne such that it can then rotate freely on the pump
shaft 1. The axial stop fingers, which are not illustrated, in the
area of the compression spring 5 limit the axial movement of the
armature element 7, such that it cannot come into contact with the
electromagnet 8 when current is flowing through the
electromagnet.
[0030] FIG. 2 shows an embodiment in which the wedge-shaped groove
2a and the engagement section 6 have been replaced by a wedge
element 9, which interacts with a conical recess 10, which matches
the wedge element 9, on the pump wheel 2. A bearing stop 11 which
is opposite the radial section 3a of the bearing bush 3 can move
axially and is pressed by a compression spring in the axial
direction against the pump wheel 2. The pump wheel 2 is therefore
moved axially in the direction of the wedge element 9, thus
resulting in a friction fit between the wedge element 9 and the
conical recess 10. In this state, the pump wheel 2 preferably runs
at the same rotation speed as the pump shaft 1.
[0031] The friction torque between the pump wheel 2 and the wedge
element 9 drives the pump wheel 2. When current is passed through
the electromagnet 8, the pump wheel 2 is drawn in the direction of
the electromagnet 8 via an armature element 13 which is arranged in
or on the pump wheel 2, thus releasing the force that is
transmitted between the wedge element 9 and the conical recess 10.
For example, the armature element 13 can be encapsulated in the
pump wheel 2. The pump wheel is pressed against the bearing stop
11, for example in the form of a steel disk, with the bearing stop
being designed such that no or essentially no drive torque is
transmitted to the pump wheel when the pump shaft 1 is rotating. In
this case, the pump wheel is disengaged, and no pump effect takes
place.
[0032] FIG. 3 shows an embodiment which operates analogously to the
embodiment shown in FIG. 2, with the difference that the elements
8, 11, 12, 13 have been transferred to the induction side while, in
contrast, the wedge element 9 and the conical recess 10 which
matches it are arranged on the side 15 remote from the induction
side 14.
[0033] In a corresponding manner to that in the exemplary
embodiment shown in FIG. 2, when no current is flowing through the
electromagnet 8, the compression spring 12 presses the pump wheel 2
against the wedge element 9, by means of which the drive torque of
the pump shaft 1 can be transmitted to the pump wheel 2 by a
friction fit. When current is passed through the electromagnet 8,
the pump wheel 2 can be disengaged, with the pump wheel 2 being
pulled away from the wedge element 9 via the armature element 13,
by means of an axial movement of the pump wheel 2 on the pump shaft
1. This represents the disengaged state.
LIST OF REFERENCE SYMBOLS
[0034] 1 Pump shaft [0035] 2 Pump wheel [0036] 2a Groove [0037] 3
Bearing bush [0038] 3a Radial section [0039] 4 Bearing stop [0040]
5 Compression spring [0041] 6 Engagement section [0042] 7 Armature
element [0043] 8 Electromagnet [0044] 9 Wedge element [0045] 10
Conical recess [0046] 11 Bearing stop [0047] 12 Compression spring
[0048] 13 Armature element [0049] 14 Induction side [0050] 15
Remote side
* * * * *