U.S. patent application number 14/886102 was filed with the patent office on 2016-02-11 for coolant pump with electric motor drive and mechanical drive.
The applicant listed for this patent is BorgWarner Inc.. Invention is credited to Thomas Buchholz, Juergen Roth.
Application Number | 20160040677 14/886102 |
Document ID | / |
Family ID | 55267091 |
Filed Date | 2016-02-11 |
United States Patent
Application |
20160040677 |
Kind Code |
A1 |
Buchholz; Thomas ; et
al. |
February 11, 2016 |
COOLANT PUMP WITH ELECTRIC MOTOR DRIVE AND MECHANICAL DRIVE
Abstract
The invention relates to a coolant pump (15) having a pump wheel
(13) which is arranged on a pump wheel shaft (3, 11); and having a
drive device (1; 8, 9) for the pump wheel (13), which drive device
has a mechanical drive (1) and which drive device has an
electric-motor drive (8, 9), wherein the pump wheel shaft is
divided into a driving section (3) and a driven section (11), and
an openable and closable clutch (4) is arranged between the driving
section (3) and the driven section (11).
Inventors: |
Buchholz; Thomas; (Stockach,
DE) ; Roth; Juergen; (Heiligenberg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BorgWarner Inc. |
Auburn Hills |
MI |
US |
|
|
Family ID: |
55267091 |
Appl. No.: |
14/886102 |
Filed: |
October 19, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12937746 |
Feb 6, 2011 |
|
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14886102 |
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Current U.S.
Class: |
417/15 |
Current CPC
Class: |
F04D 13/06 20130101;
F04D 13/024 20130101; F04D 15/0066 20130101; F01P 5/12 20130101;
F01P 7/164 20130101; F01P 7/162 20130101; F04D 13/02 20130101 |
International
Class: |
F04D 15/00 20060101
F04D015/00; F01P 5/12 20060101 F01P005/12; F04D 29/18 20060101
F04D029/18; F04D 13/06 20060101 F04D013/06; F04D 29/043 20060101
F04D029/043 |
Claims
1. A method for operating a dual mode coolant pump for a vehicle
engine, said coolant pump comprising an impeller shaft having a
driving section and a driven section, an impeller member at one end
of said shaft for circulating coolant in said engine, an electric
motor drive for rotating said impeller shaft at said driven
section, a mechanical drive for rotating said impeller shaft at
said driving section, a clutch mechanism for engaging and
disengaging said mechanical drive from said impeller shaft, and a
control system for activating and deactivating said mechanical
drive and said electric motor drive, said method of operating said
coolant pump comprising: activating said electric motor drive and
deactivating said mechanical drive for pumping coolant through said
engine during a first range of impeller rotation speed; activating
said mechanical drive and deactiving said electric motor drive for
pumping coolant through said engine during a second range of
impeller rotation speed; said second range of impeller rotation
speed being greater than said first range of impeller rotation
speed.
2. The method as set forth in claim 1 wherein said first range of
impeller rotation speed is from about 1000 rpm to about 1500
rpm.
3. The method as set forth in claim 1 wherein said second range of
impeller rotation is from about 1000 rpm to about 2500 rpm.
4. The method as set forth in claim 1 wherein said electric motor
is a brushless DC motor.
5. The method as set forth in claim 1 wherein said mechanical drive
comprises a pulley.
6. The method as set forth in claim 1 wherein said clutch mechanism
is an openable and closeable clutch.
7. The method as set forth in claim 1 wherein said mechanical drive
is engaged on the basis of pressure measurements.
8. The method as set forth in claim 1 wherein said mechanical drive
is engaged on the basis of monitoring of supply of electrical
energy.
9. The method as set forth in claim 1 wherein said first range of
impeller rotation speed comprises coolant temperature from about
80.degree. C. to about 94.degree. C.
10. The method as set forth in claim 1 wherein said second range of
impeller rotation speed comprises coolant temperature from about
90.degree. C. to about 96.degree. C.
11. The method as set forth in claim 1 wherein an auxiliary coolant
pump is not required for the vehicle engine.
12. The method as set forth in claim 1 further comprising the step
of recovering electrical energy from the electric motor drive when
said mechanical drive is exclusively activated.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. patent application Ser. No.
12/937,746, filed on Feb. 6, 2011. This application is also related
to U.S. patent application Ser. No. 14/517,914 and U.S. patent
application Ser. No. 14/517,916, both filed on Oct. 19, 2014.
TECHNICAL FIELD
[0002] The present invention relates to coolant pumps which have
both a mechanical mode of operation and an electric mode of
operation.
BACKGROUND OF THE INVENTION
[0003] A coolant pump of said type is known from DE 102 14 637
A1.
[0004] To be able to realize different driving operation states of
a vehicle with said coolant pump, which has both an electric-motor
drive and also a mechanical drive, a planetary drive is provided
which can be driven by the electric motor and/or by the mechanical
drive.
[0005] Said design is however complex with regard to its mechanical
construction and is susceptible to faults.
[0006] It is therefore an object of the present invention to create
a coolant pump, the design of which coolant pump is simplified in
relation to the prior art and the operation of which coolant pump
is efficient and fail-safe.
SUMMARY OF THE INVENTION
[0007] As a result of the pump wheel shaft being divided into a
driving section and a driven section which is separate from said
driving section, and as a result of the provision of a clutch which
is arranged between the driving section and the driven section and
which can be opened in order to separate said two sections and
which can be closed in order to connect the two sections, it is
possible in an extremely simple manner for the pump wheel to be
driven both by the electric-motor drive and also by the mechanical
drive, in each case independently.
[0008] The present invention is based on the concept of providing
two pump types, such that the mechanical pump takes over the
function of the electric pump in order to boost the pump power for
operating conditions for which the electric pump would be too weak.
In this way, it is also possible to obtain a fail-safe function for
the electric pump, since it is possible according to the invention
to couple in the mechanical pump if an interruption occurs in the
electrical energy supply for the electric pump.
[0009] In principle, the following implementations of the invention
are possible:
[0010] Although it is fundamentally possible to operate both pump
types in parallel, it is particularly preferably provided according
to the invention that the electric pump and the mechanical pump are
connected in series, with a regulated clutch performing the
function of coupling in the mechanical pump, for example on the
basis of pressure measurements or monitoring of the electrical
energy supply.
[0011] In the case of a sequential arrangement of the mechanically
operated pump and the electrically operated pump, it is preferably
possible, for both pumps to use a single pump wheel.
[0012] It is also possible according to the invention, as a result
of a downsizing of the coolant pump, for said coolant pump to be
adapted both for the utility vehicle field and also for the
passenger vehicle field, wherein in the case in particular of the
passenger vehicle field, the warm-up behavior of the engine can be
improved by precise adjustment of the basic coolant flow.
[0013] In hybrid vehicles, the concept according to the invention
may also provide a coolant flow when the engine is stopped. The
coolant flow is required for the functioning of the
alternator/generator and for the battery. The coolant flow which is
required may accordingly be provided by the combination according
to the invention of the electric pump and of the mechanically
driven pump, without an auxiliary pump being required, as in the
prior art.
[0014] This yields the following advantages:
[0015] More fail-safe design of the entire system, since it is
possible, when the electric-motor drive is deactivated, for the
pump wheel to be actuated solely by means of the mechanical drive.
The decoupling from the mechanical drive takes place by means of an
actuation of the clutch. In the rest position of the clutch, the
pump wheel shaft is driven by the mechanical drive.
[0016] Two operating principles for actuating a driving side,
wherein the two driving sides can be decoupled entirely from the
driven side, or the two driving sides can be decoupled only
individually from the driven side.
[0017] In-line concept for coupling/decoupling with electric-motor
drive. The electric-motor drive, which is preferably designed as a
brushless direct-current motor, is arranged on the driven side of
the pump wheel shaft. The mechanical drive and also the
electric-motor drive may, connected by the clutch, be arranged in
alignment on the same axis of the coolant pump, and drive only a
single pump wheel.
[0018] The concept of the coolant pump according to the invention
is compatible with different coolant pump designs.
[0019] The coolant pump according to the invention can provide
hydraulic energy when the internal combustion engine is at a
standstill, if the coolant pump is for an internal combustion
engine of a passenger vehicle. Post-operation cooling can take
place via the main pump wheel by means of drive by means of the
electric motor.
[0020] Sequential operating logic can be obtained with the coolant
pump according to the invention, since the pump wheel can be driven
either by the electric motor or by the mechanical drive.
[0021] The bearings on the driving side and on the driven side can
be arranged in alignment on the same axle, wherein all of the inner
rings rotate.
[0022] It is possible to recover electrical energy from the
electric-motor drive (generator operation) when the pump wheel is
being driven exclusively by the mechanical drive. From an energetic
aspect, this is particularly expedient in the overrun mode of the
internal combustion engine.
[0023] The provision of sufficient cooling power for most operating
states by decoupling the mechanical drive and operation by means of
the electric motor.
[0024] As a result of the quadratic power characteristic curve of a
coolant pump, the electric motor provides a basic volume flow,
wherein the maximum delivery power for maximum cooling power takes
place by coupling the mechanical drive (without electric-motor
pump).
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Further details, advantages and features of the present
invention can be gathered from the following description of an
exemplary embodiment on the basis of the drawing, in which:
[0026] FIG. 1 shows a sectioned illustration through an embodiment
of a coolant pump according to the invention;
[0027] FIG. 2 shows a schematic construction of a cooling circuit
of an internal combustion engine having the coolant pump according
to the invention; and
[0028] FIGS. 3 and 4 show two statistical distribution plots of the
pump wheel rotational speed in relation to the engine speed for two
transient driving cycles.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] FIG. 1 shows a sectioned illustration through an embodiment
of a coolant pump 15 according to the invention. The coolant pump
15 has a pump wheel 13 which is arranged on a pump wheel shaft. The
pump wheel shaft is divided into a driving section 3 and a driven
section 11. In the illustrated embodiment, the driving section 3 is
formed as a flange, to which a mechanical drive 1, in the form of a
belt pulley in this example, is rotationally fixedly connected. In
the illustrated embodiment, the arrangement composed of a flange 3
and a belt pulley 1 is mounted in a housing 7 by means of a bearing
(not shown).
[0030] The mechanical drive 1 may be connected to an internal
combustion engine of a motor vehicle, wherein in the illustrated
embodiment, it is possible to use a belt drive, of which, however,
only the belt pulley 1 is shown in order to simplify the
illustration.
[0031] The driven section 11 of the pump wheel shaft is mounted in
the housing 7 by means of two bearings 5 and 10, and at its free
end 16, supports the pump wheel 13. Here, the free end 16 of the
driven section 11 is sealed off with respect to the housing 7 by
means of a seal 12 which is arranged between the pump wheel 13 and
the bearing 10.
[0032] As is also shown in FIG. 1, the driven section 11 and the
driving section 3 of the pump wheel shaft can be connected by means
of a clutch 4 which is arranged between the two sections 3 and 11.
The clutch 4 may for example be embodied as an electromagnetic
clutch with a coil 5.
[0033] An electric-motor drive is also assigned to the driven
section 11 of the pump wheel shaft, which electric-motor drive is
arranged, with its rotor 9 and a stator 8 which surrounds said
rotor 9, in alignment with the lo mechanical drive 3 on the driven
section 11. Here, as shown in FIG. 1, the rotor 9 and the stator 8
are held in a housing 7.
[0034] Finally, a Hall effect device 14 is arranged between the
rotor 9 and the bearing 6.
[0035] With said design of the coolant pump 15 according to the
invention, it is possible for the pump wheel 13 to be completely
separated from the mechanical drive 1 by opening the clutch 4.
Here, the electric-motor drive, which is preferably embodied as a
brushless direct-current motor, is arranged on the side of the
driven section 11 of the pump wheel shaft, in order to be able to
provide a regulable coolant flow in a predeterminable power range,
which is completely independent of the rotational speed of the
motor to which the coolant pump 15 is connected, when the driven
section 11 is separated from the driving section 3 by the opened
clutch.
[0036] For this purpose, the rotor 9 of the electric-motor drive is
arranged directly on the driven section 11 of the pump wheel shaft,
as can be seen from FIG. 1. The stator 8 is integrated, around the
same axis of the housing 7, in the housing 7 around the rotor 9, as
can likewise be seen from FIG. 1.
[0037] The electric-motor drive 8, 9 can be regulated by means of a
commutated signal from an electronic regulating device (not
illustrated in any more detail in FIG. 1). If the driven side 11 is
separated from the driving side 1, 3, the pump wheel 13 can be
driven solely by the electric-motor drive 8, 9. Here, it is
provided that sufficient hydraulic output power is provided in
order to provide the required coolant flow for all normal operating
conditions of the engine which is connected to the coolant pump 15.
To obtain a maximum available coolant flow, the driven section 11
can be connected to the driving section 1, 3 of the pump wheel
shaft by means of the clutch 4. In said case, the pump wheel 13 is
driven solely by the mechanical drive 1 when the electric motor 8,
9 is deactivated. If appropriate, the electric motor 8, 9 may be
activated.
[0038] FIG. 2 illustrates a schematic construction of a possible
cooling circuit of an internal combustion engine 17 which uses the
coolant pump 15 according to the invention. In said schematically
highly simplified illustration, the pump which is driven by an
electric motor is denoted by the reference symbol 20 and the
mechanically driven pump is denoted by the reference symbol 21. The
two pumps, which are arranged in series, may be connected via the
clutch 4 to a belt drive 2 and via the belt pulley 1 to the engine
17 for the provision of the required mechanical drive energy. In
the illustrated embodiment, the coolant circuit also has a
thermostat 18 and a cooler 19, the interaction of which is shown by
the plotted arrows, in which regard reference is made explicitly to
the graphic illustration of FIG. 2.
[0039] FIGS. 3 and 4 show data of two transient driving cycles, in
which regard reference is made to FIGS. 3 and 4 with the curves and
entries plotted therein.
[0040] In addition to the above written disclosure of the
invention, reference is hereby explicitly made to the graphic
illustration of said illustration of said invention in FIGS. 1 to
3.
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