U.S. patent application number 09/971342 was filed with the patent office on 2002-04-18 for electrical transmission system.
Invention is credited to Bachmann, Max, Ott, Herbert.
Application Number | 20020043074 09/971342 |
Document ID | / |
Family ID | 7659875 |
Filed Date | 2002-04-18 |
United States Patent
Application |
20020043074 |
Kind Code |
A1 |
Ott, Herbert ; et
al. |
April 18, 2002 |
Electrical transmission system
Abstract
The electrical transmission system for a motor vehicle having a
traction input, a power electronic system that controls the
traction input and a cooling system for cooling the power
electronic system. The cooling system is a refrigerator, or
possibly a heat pump, with an integrated carburetor and a
compressor unit. The electrical transmission system is particularly
suitable for urban buses.
Inventors: |
Ott, Herbert; (Meckenbeuren,
DE) ; Bachmann, Max; (Bad Waldsee, DE) |
Correspondence
Address: |
DAVIS & BUJOLD, P.L.L.C.
500 NORTH COMMERCIAL STREET
FOURTH FLOOR
MANCHESTER
NH
03101
US
|
Family ID: |
7659875 |
Appl. No.: |
09/971342 |
Filed: |
October 4, 2001 |
Current U.S.
Class: |
62/259.2 ;
62/323.1 |
Current CPC
Class: |
B60K 11/02 20130101;
B60K 7/0007 20130101 |
Class at
Publication: |
62/259.2 ;
62/323.1 |
International
Class: |
F25D 023/12; F25B
027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 14, 2000 |
DE |
100 51 092.2 |
Claims
1. Electrical transmission system for motor vehicles, specially
urban buses, having a traction input, a power electronic system
that controls it and a cooling system for the power electronic
system, characterized in that the cooling system is a refrigerator
with integrated carburetor and compressor unit.
2. Transmission system according to claim 1, characterized in that
said refrigerator is connected via a primary circuit with the parts
to be cooled of the power electronic system.
3. Transmission system according to claim 1, characterized in that
said refrigerator is connected via a secondary circuit with the
parts to be cooled of the power electronic system.
4. Transmission system according to any one of the preceding
claims, characterized in that the cooling system is provided with a
terminal for connection with an air-conditioning equipment in the
motor vehicle.
5. Transmission system according to any one of the preceding
claims, characterized in that said refrigerator is provided with a
terminal for connection with a fuel cell cooling existing in the
motor vehicle.
6. Transmission system according to any one of the preceding
claims, characterized in that the cooling system is provided with a
terminal for connection with the internal combustion engine cooling
existing in the motor vehicle.
Description
[0001] According to the preamble of claim 1, this invention
concerns an electrical transmission system for motor vehicles,
specially urban buses, having a traction input and a power
electronic system that controls it.
[0002] Electrical transmission system known already, specially for
urban buses, have a traction input in the form of an electromotor
which is often designed as asynchronous machine, that is, having a
stator and a rotor provided in the stator. The rotor is usually
designed as squirrel cage motor and consists of electrically
conductive aluminum which in the form of a pressure casting can be
shaped as a rotor. During production the aluminum is preferably
poured in the grooves formed by the laminated bundle of the rotor
wherein on the front side of the rotor aluminum rods from the
respective grooves are interlocked and thus short circuited. Such
asynchronous motors are chiefly highly utilized motors whose heat
development needs an optimized cooling.
[0003] EP 0 484,548 has disclosed such as electrical machine with
an internal rotor with rotor shaft and with a rotor laminated
bundle with external stator. Said electrical machine is connected
with the coolant circuit of the vehicle.
[0004] However, the transportation of coolant in such an electrical
machine is made difficult by the structurally determined spatial
limitation whereby the collected heat amounts can be removed only
with difficulty, specially in highly used machines.
[0005] In the Applicant's German Patent Application No. 199 055 38
an electromotor was proposed for driving vehicles which has an
external stator, an internal pivotally mounted rotor, a rotor
laminated bundle and a rotor shaft non-turnably connected with the
rotor laminated bundle, the rotor being designed hollow and the
rotor shaft as spider shaft. The spider shaft has on its periphery
a number of webs which, to form small heat-transfer surfaces, abut
only on almost linear contact surface on the rotor laminated
bundle. The webs are designed so as to have the needed strength and
rigidity but a small surface contact with the heat-generating
laminated bundle.
[0006] It is thus possible to protect the support of the rotor
shaft and the seals thereof against damages resulting from the high
amounts of heat transferred to the bearings.
[0007] The Applicant's German Patent Application No. 199 055 39 has
disclosed one other electromotor for driving vehicles in which a
gear exchanger for cooling a coolant used in the electromotor is
integrated in the electromotor wherein the coolant can be passed in
the ducts having large cross-sections and wherein the heat
exchanger can be placed in one of said ducts. The heat exchanger
can here be provided with cooling tubes which surround the stator,
it being possible for the cooling tubes in the heat exchanger to be
connected with cooling webs for heat transfer.
[0008] The Applicant's German Patent Application No. 199 055 40
finally describes an electromotor for driving vehicles having an
external stator and an internal pivotally mounted rotor with a
laminated bundle wand with a rotor shaft non-turnably connected
with the rotor laminated bundle, the rotor being designed hollow
and in the area between rotor laminated bundle and rotor shaft, a
coolant is passed through. The rotor shaft can be designed in the
shape of a worm conveyor or be provided with vent devices on an
least one of its axial ends for enlarging the flow rate or the feed
pressure of the coolant. Thereby is made possible an improved
transportation of the coolant so that the support of the machine be
protected from damages.
[0009] However, together with said different parts of the
electromotor, the power electronics of such traction inputs must be
cooled. The degree of effectiveness of the parts used therein
depends on the operating temperature. With adequately low coolant
temperature it is possible to change over to a correspondingly high
power. In case of automotive utilizations, it is then possible with
the conventional hot air exchangers no longer to cool the initial
temperature to below 50.degree. C. when the cool air already has a
temperature of 40.degree. C.
[0010] The problem to be solved by this invention is to provide an
effective cooling system for the power electronics of traction
inputs.
[0011] Based on an electrical transmission system for motor
vehicles and specially urban buses of the kind specifically
mentioned above, this problem i solved by the feature stated in the
characteristic part of claim 1; advantageous developments are
described in the sub-claims.
[0012] Therefore, it is provided according to the invention that
the cooling system for the power electronics consists of a
refrigerator or heat pump with integrated carburetor and compressor
unit. The coolant can thus be brought to adequately low temperature
according to the lay out.
[0013] The coolant of the refrigerator or heat pump can be used
directly for cooling the corresponding parts of the power
electronics; the coolant can also be used to cool the parts
indirectly via a secondary circuit.
[0014] In vehicles having built-in air conditioning equipment, the
latter can be switched on as additional cooling system via an
adequate terminal.
[0015] The inventive installation of a refrigerator or heat pump
reduces the temperature of the parts thus leading to increased
effectiveness. A reduction in weight and installation space of the
traditional coolers is at the same time made possible. When a heat
pum is used, the reverse temperature can be set adequately high so
as to have a great difference from the temperature of the cool air.
With a temperature difference adequately great, the specific
cooling capacity is in creased and a slimmer cooling surface design
is made possible.
[0016] By adequate selection of the coolant and of the pressure
level of the heat pump or refrigerator, the reverse cooling to high
temperature level is also possible so that the connection can also
be implemented on existing cooling units such as fuel cell cooling,
internal combustion engine cooling, air conditioning systems,
etc.
[0017] The existing air conditioning in the vehicle can even be
used as heat pump for direct or indirect cooling.
[0018] With multiple use of the existing units a reduction of the
total weight can be obtained. A reduction fo the number of parts at
the same time allows in turn a higher reliability of the whole
system.
[0019] According to the invention, by heat pump is understood in
the conventional sense an arrangement where in a cycle process with
the aid of supplied work a temperature difference is created
wherein heat from a heat accumulator of lower temperature is pumped
into one with higher temperature. Conversely, in a traditional
refrigerator according to the 2.sup.nd law of thermodynamics, the
reduction fo he entropy of the system related to the product of a
temperature difference is compensated by supplying labor or
heat.
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