DE102021129530A1 - Double impeller cooling water pump for electric vehicles and cooling circuit for a thermal management module with an electric water pump - Google Patents

Abstract

The invention relates to an electric water pump (1) for a cooling circuit of an electric vehicle, with an electric motor (2) driving a shaft (5) which is coupled to at least one impeller (3, 4), with at least two impellers (3 and 4 ) are mounted on the shaft (5) on one side of the electric motor (2). The invention also relates to a cooling circuit (14) for a thermal management module with a pipe system (16) into which one or more valves (19, 20, 23) and a water pump (1) of the type according to the invention are integrated in order to to form sub-cycles.

Description

The invention relates to an electric water pump for a cooling circuit of an electric vehicle (Battery Electric vehicle; BEv), with an electric motor driving a (drive) shaft which is coupled/fixedly connected to at least one impeller/pump wheel/vane wheel.

From the prior art are already electric water pumps and drive control method of electric brushless DC motors, for example from DE 10 2017 222 602 A1 , known. There, a method and a system for controlling a drive of an electric brushless DC motor of an electric water pump is presented. The method relates to estimating an initial position of a rotor using a magnitude of a current generated in a three-phase coil wound on a stator and converting a current magnitude reflecting a rotation angle of the rotor with respect to the initial position based on the rotary phase current into two direct currents. The converted DC currents are output, and a rotation angle, speed, flux, and torque of the motor are detected based on values of the three-phase current, a voltage generated according to the flow of the three-phase current, a predetermined coil resistance, and an inductance input. A speed of the motor is then adjusted based on the detected rotation angle, speed, flux and torque of the rotor.

Water pumps and drives for such water pumps are also from the DE 2012 222 781 A1 known. There, a coolant pump for a cooling circuit of an internal combustion engine is presented with a pump housing in which a drive shaft is mounted, which can be driven via a drive wheel and at one end of which a pump wheel is attached, through which a cooling medium flows, with the coolant pump being driven directly by the exhaust gas pressure of the internal combustion engine by the drive wheel being arranged in an exhaust system of the internal combustion engine.

There are also thermal management modules, for example from the DE 10 2016 210 477 A1 , known. A thermal management module is proposed therein, which comprises a rotary slide with a coolant channel and a primary seal resting on the rotary slide for sealing the coolant channel. The rotation of the rotary valve is intended to force a rotation of the primary seal perpendicular thereto.

The electrification of motor vehicles entails increasingly complex coolant circuit architectures. Within these circuits, several sub-circuits must be thermally separated from one another. The separation is currently being completed by installing several electric water pumps. This causes high costs. For example, it is deplorable that the use of electric water pumps can account for around 75% of the added value of a control system. Here it is necessary to take action to improve.

It is the object of the present invention to eliminate or at least alleviate the disadvantages of the prior art.

In a water pump mentioned at the outset, this is achieved according to the invention in that at least two impellers are mounted on the shaft on one side of the electric motor. Such a double or multiple impeller can almost halve the costs.

The focus of the invention is therefore a modified architecture corresponding to the use of throttles, bypass and mixing valves for hydraulic and thermal decoupling. This allows the pump function to be coupled mechanically within a double impeller pump. The invention includes a water pump based on a dry-running or wet-running principle. A double impeller according to the invention thermally separates the circuits from one another. The inflow is optimized by a coaxial channel layout. Maximum pump capacities and pressures can be designed by varying the outer diameter and the length of the pump vanes. Two or more pump rooms can be mapped. The impeller may be injection molded as one piece or assembled from multiple shells by, for example, plastic welding.

Advantageous embodiments are claimed in the dependent claims and are explained in more detail below.

It is advantageous if the at least two impellers are arranged one behind the other in the longitudinal direction of the shaft, ie next to one another when viewed from the side. A compact design can then be implemented.

If a housing is used that is designed in such a way that it provides a separate delivery point for each impeller, it is possible to ensure that the individual sub-circuits are kept separate. It is important that one delivery point is fluidically/hydraulically separated from the other delivery points.

It has proven useful if the housing is separated and/or subdivided in such a way that separate channels lead to the delivery point or points.

Manufacturing can be simplified if the impellers are designed as impellers.

It is advantageous if exactly two impellers or more than two impellers are present.

On the one hand, longevity is increased and, on the other hand, production costs are reduced if two impellers are designed as a preferably one-piece/single-material double impeller.

An advantageous embodiment is also characterized in that each impeller has a suction channel aligned in the longitudinal direction of the shaft. One suction channel can be a tube and the other suction channel can be a circular ring cross-section sleeve.

It has proven useful if the suction channels are arranged concentrically with one another.

In order to be able to implement different conveying properties, it has proven useful if the impellers differ in their geometric data of the pump blade length and/or outer diameter. As an alternative to this, they can of course also be configured identically or at least in a highly similar manner.

The invention also relates to a cooling circuit for a thermal management module with a pipe system in which one or more valves and a water pump of the type according to the invention are integrated in order to form a plurality of partial circuits/sub-circuits, with one or more heat exchangers preferably being integrated are involved.

For example, "chillers" can be installed to exchange heat between a cooling circuit and a refrigeration circuit.

• 1 eine perspektivische Darstellung einer erfindungsgemäßen Wasserpumpe, wobei das Gehäuse nicht dargestellt ist,
• 2 einen Längsschnitt durch die erfindungsgemäße Wasserpumpe aus 1,
• 3 eine Draufsicht auf die Wasserpumpe der 1 und 2 entlang der Längsachse der Wasserpumpe, bestimmt durch die Längsachse einer von einem Elektromotor antreibbaren oder angetriebenen Welle, und
• 4 bis 6 mehrere hydraulische Entkoppelungen in einem Kühlkreislauf u.a. für ein Thermo-Management-Modul.

The invention is explained in more detail below with the aid of a drawing. Show it:

• 1 a perspective view of a water pump according to the invention, the housing not being shown,
• 2 a longitudinal section through the water pump according to the invention 1 ,
• 3 a top view of the water pump 1 and 2 along the longitudinal axis of the water pump, determined by the longitudinal axis of a driveable or driven by an electric motor shaft, and
• 4 until 6 several hydraulic decouplings in a cooling circuit, among other things for a thermal management module.

The figures are only of a schematic nature and only serve to understand the invention. The same elements are provided with the same reference numbers. Features of the individual embodiments can be interchanged.

In the 1 1 shows an electric water pump 1 according to a first embodiment of the invention. It has at least one electric motor 2 as a drive and a first impeller 3 and a second impeller 4 on a common shaft 5.

The shaft 5 defines the axial direction 6 . This also determines the radial direction 7 . The circumferential direction is referenced with reference number 8 .

The shaft 5 protrudes from an end face 9 of the electric motor 2. The combination of the first impeller 3 and the second impeller 4 is fastened on the shaft 5 as a common, integral/single-material/one-piece component. The first impeller 3 has a first suction channel 10, whereas the second impeller 4 has a second suction channel 11. How particularly good also in the 2 As can be seen, pump blades 12 of the first impeller 3 differ from pump blades 13 of the second impeller 4. The two impellers 3 and 4 are arranged on one and the same end face 9 of the electric motor 2. The concentric structure of the water pump 1 is the 3 good to take.

In the 4 until 6 different cooling circuits 14 are shown as examples: a chiller 15 is integrated into a pipe system 16 . Furthermore, high-voltage battery components 17 and main cycle components 18 are involved. There are also several valves 19 and 20. The electric motor 2 can be designed as a DC motor. A AGB 21 and a radiator 22 may be present.

A special feature in the hydraulic decoupling is the 4 realized a bypass, whereas in the hydraulic decoupling after 5 a throttle valve 23 is used in a switching logic (possibly integrable in TMM).

In the hydraulic decoupling after 6 this is done by mixing, with two valves 19 designed as proportional valves being used. It can be implemented using a common proportional valve, e.g. as an extended SANHUA.

Reference List

1

(electric) water pump

2

Electric motor / DC motor

3

first impeller

4

second impeller

5

shaft / drive shaft

6

axial direction

7

radial direction

8th

circumferential direction

9

face

10

first suction channel

11

second suction channel

12

Pump blade of the first impeller

13

Pump blade of the second impeller

14

cooling circuit

15

chillers

16

pipe system

17

high-voltage battery components

18

Major Cycle Components

19

Valve

20

Valve

21

AGW

22

radiator

23

throttle valve

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102017222602 A1 [0002]
• DE 2012222781 A1 [0003]
• DE 102016210477 A1 [0004]

Claims (10)

Water pump (1) for a cooling circuit of an electric vehicle, with an electric motor (2) driving a shaft (5) which is coupled to at least one impeller (3, 4), with at least two impellers (3 and 4) on one side of the Electric motor (2) are mounted on the shaft (5). water pump (1) after claim 1 , characterized in that the at least two impellers (3 and 4) are arranged one behind the other in the longitudinal direction of the shaft (5). Water pump (1) according to one of Claims 1 or 2 , characterized in that a housing is designed in such a way that it provides its own delivery point for each impeller (3 and 4). water pump (1) after claim 3 , characterized in that the housing is separated and/or subdivided in such a way that separate channels lead to the conveying points. Water pump (1) according to one of Claims 1 until 4 , characterized in that the impellers (3 and 4) are designed as impellers. Water pump (1) according to one of Claims 1 until 5 , characterized in that two impellers (3 and 4) are designed as a double impeller. Water pump (1) according to one of Claims 1 until 6 , characterized in that each impeller (3 and 4) has a suction channel (10 and 11) aligned in the longitudinal direction of the shaft (5). water pump (1) after claim 7 , characterized in that the suction channels (10 and 11) are arranged concentrically to one another. Water pump (1) according to one of Claims 1 until 8th , characterized in that the impellers (3 and 4) differ in their geometry data of the pump blade length and/or outer diameter. Cooling circuit (14) for a thermal management module with a pipe system (16) into which one or more valves (19, 20, 23) and a water pump (1) according to one of the preceding claims are integrated in order to form a number of partial circuits.

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