WO2015121051A1

WO2015121051A1 - Electric motor vehicle coolant pump

Info

Publication number: WO2015121051A1
Application number: PCT/EP2015/051395
Authority: WO
Inventors: Toni Henke; Kathrin Holzbauer; Alexander Findeisen
Original assignee: Pierburg Pump Technology Gmbh
Priority date: 2014-02-11
Filing date: 2015-01-23
Publication date: 2015-08-20
Also published as: EP2905471A1; EP2905471B1

Abstract

The invention relates to an electric motor vehicle coolant pump (10) with a pump rotor (20), a motor section (14) with a permanently magnetic motor rotor (30), a motor stator (32) having motor coils (33), and a can (40) which separates the motor stator (32) from the motor rotor (30) in a fluid-tight fashion, and a control section (16) having a control space (70) in which the motor controller (71) is arranged. The control space (70) is separated from the motor section (14) by a plastic dividing wall (50) lying essentially in a transverse plane. The dividing wall (50) has a heat-transmitting opening (64) in which a thermal conductor (66) is arranged, one of the longitudinal ends of which thermal conductor (66) being in heat-conducting contact with the can (40), and the other longitudinal end of which thermal conductor (66) being in heat-conducting contact with the motor controller (71). The specific thermal conductivity of the thermal conductor (66) is higher than the specific thermal conductivity of the dividing wall plastic.

Description

Electric vehicle coolant pump

The invention relates to an electric motor vehicle coolant pump, which is driven by an electric drive motor, which is designed as a so-called canned motor.

A motor vehicle coolant pump serves to pump a liquid heat carrier, hereinafter referred to as coolant, in a heating or cooling circuit. The coolant circuit does not necessarily have to be a main flow of the circuit, but may also form a side stream. For an opening-free separation of the wet area from the dry area of the coolant pump so-called canned motors are used as drive motors, which are commutated electronically. The motor rotor is arranged in the wet area, whereas the motor stator forming the motor coils are arranged in the dry area. The motor rotor room and the Motorstator- space are separated from each other by a liquid-tight by a generally cylindrical gap tube.

The problem with an electronically commutated drive motor is basically the cooling of the motor control, which has a plurality of power semiconductors for controlling the motor coils, which must heat up considerably during operation and must be cooled accordingly in order to prevent their destruction. The motor coils are another heat source that should be thermally shielded as well as possible with respect to the motor control. To cool the power semiconductors, it makes sense to use this for the coolant flowing through the coolant pump. From EP 2 469 102 AI an electric motor vehicle coolant pump is known, the canned drive motor is electronically commutated. The cooling of the electronic engine control via a substantially arranged in a transverse plane partition, which separates the wet space in which the permanent magnet motor rotor is arranged from the control room in which the electronic engine control is arranged. In practice, the dividing wall often consists of a material with good heat conduction, in order to ensure a good heat flow from the engine control through the dividing wall to the coolant. However, since the partition also separates the motor coils from the control room, heat from the motor coils into the control room can also be entered via this path.

Object of the invention against this background is to provide an electric motor vehicle coolant pump with improved cooling of the engine control.

This object is achieved by an electric motor vehicle coolant pump having the features of claim 1.

The electric motor vehicle coolant pump according to the invention has a pump unit, which is driven by the electric drive motor. The pump unit may for example be designed as a so-called impeller having a central axial inlet and the liquid coolant pumped radially outward. In the motor section a permanent magnetically excited motor rotor, a motor stator having a plurality of motor coils and a split pot is provided, which liquid-tightly separates the motor stator from the motor rotor. The fixed motor coils are preferably arranged annularly around the rotating motor rotor. Furthermore, the Coolant pump on a control section with a control room, in which the engine control is arranged.

The control room is hermetically separated from the motor section by a plastic partition wall lying essentially in a transverse plane, so that the partition wall shields the control room from the containment shell insulating the wet space with the motor stator. The partition wall has a heat transfer opening in which a heat conductor is arranged which is in heat-conducting contact with the split pot with its one axial longitudinal end and in heat-conducting contact with the motor control at its other axial longitudinal end. The specific thermal conductivity of the heat conductor is higher than the specific thermal conductivity of the partition wall plastic. Particularly preferably, the specific thermal conductivity of the heat conductor is at least twice as high as the specific thermal conductivity of the partition wall plastic.

Due to the plastic partition wall, the control room with the motor control is thermally well insulated and shielded from the motor section, in which inter alia, the heat generating motor coils are arranged. The heat input of the motor coils in the control room is reduced in this way to a minimum. However, the heat conductor in the heat transfer opening of the partition wall produces "pointwise" a thermal bridge between the motor control and the containment shell, which preferably consists of a material with a relatively high specific heat conductivity. The heat conductor is spatially preferably arranged where the motor control generates the most heat, ie in the vicinity of the power semiconductors.

By the plastic partition wall including the partition axially penetrating heat conductor on the one hand, a good thermal Isolation of the control room with respect to the motor coils and on the other hand realized a targeted heat dissipation from the engine control to the containment shell.

The heat conductor is preferably formed by a thermal adhesive or a non-adhesive thermal compound that completely fills and closes the heat transfer opening so that the motor section is fluidically completely isolated from the control section. By the thermal adhesive is permanently a gap-free connection of the heat conductor to the containment shell on the one hand and the engine control on the other hand ensured. The heat conductor can also be designed to be elastic and clamped axially between the motor control and the containment shell, so that a gap-free thermal connection of the heat conductor to the containment shell and the motor control is permanently ensured in this way.

Alternatively or additionally, the heat conductor can also be formed by a rigid and prefabricated solid, for example, a metal body or a ceramic body, which is particularly preferably thermally coupled by a thermal adhesive or a thermal mass gap-free to the engine control and the containment shell, but (electrically insulating) formed is.

Preferably, the heat conductor is designed as an electrical insulator. In this way, the heat conductor can be thermally coupled directly to a conductor track or to a power semiconductor without thereby producing an electrical connection from the conductor track or the power semiconductor to the containment shell. Preferably, the heat transfer opening is formed by a sleeve body whose axial length substantially corresponds to the axial distance between the containment shell and the engine control. The axial length of the sleeve body is greater than the axial wall thickness of the partition wall, so that the sleeve body axially projects beyond the partition wall on one or both axial sides.

Preferably, the plastic partition forms the only spatial separation between the motor coils and the control room. Since the plastic baffle forms good thermal insulation, another baffle is not required to ensure good thermal isolation of the motor bobbins from the control room.

According to a preferred embodiment, the plastic partition wall is an integral part of a plastic housing body which radially surrounds the motor stator and / or the control room. As a result, the additional production cost for the partition is kept relatively low.

Preferably, the containment shell is made of metal, which has a good thermal conductivity. Compared to a containment shell made of plastic, a metal containment shell has the advantage of being absolutely leakproof with respect to liquids such as water or water vapor, so that a transfer of moisture into the control room is excluded.

According to a preferred embodiment, the containment shell has a substantially lying in a transverse plane pot bottom, which is in heat-conducting contact with the heat conductor directly. The heat conductor or the heat transfer opening is within the axial projection of the pot bottom. Preferably, the motor control is arranged on a standing in a transverse plane board and has the motor control power semiconductors, which are directly or indirectly connected via separate guide elements thermally conductive to the heat conductor. When the power semiconductors are located on the distal side of the board, the heat is conducted through the routing elements to the proximal side of the board. Alternatively, the power semiconductors may be arranged on the proximal side of the board facing the plastic partition wall so that the cooling vanes of the power semiconductors are connected directly to the heat conductor with the heat conductor.

The heat-conducting elements of the motor control board are particularly preferably formed by metal sleeves, metal sleeves filled with a heat conductor and / or metal pins which are inserted in the board. The power semiconductors may in this case be arranged on the distal side of the circuit board, wherein the heat conduction elements establish the thermal connection through the circuit board to the proximal side of the circuit board. Particularly preferably, the power semiconductors are arranged in close proximity to the heat conductor, so that the heat path is short and the absolute thermal resistance between the power semiconductors and the heat conductor is low.

In the following an embodiment of the invention will be explained in more detail with reference to the drawings. Show it :

1 shows a longitudinal section of an electrical motor vehicle coolant pump with a plastic partition, which has a heat transfer opening in which a heat conductor is arranged, Figure 2 shows the proximal side of the partition wall of Figure 1 in a perspective view, and

3 shows the distal side of the partition wall of Figure 1 in a perspective view.

FIG. 1 shows an electric motor vehicle coolant pump 10 which, for example, serves to pump a liquid coolant, for example water, for cooling an internal combustion engine or another unit in a cooling circuit of a motor vehicle.

The coolant pump 10 has three sections in the axial direction, namely a pump section 12, a motor section 14 adjoining thereto and a control section 16 adjoining the motor section 14. In the pump section 12, a pump rotor 20 is arranged, which in the present case is a so-called impeller axial central inlet and the coolant pumps radially outward. The pump rotor 20 is driven by an electronically commutated drive motor, which is essentially formed by a permanent magnetically excited motor rotor 30 and these coaxial and annular motor coils 33 surrounding the motor rotor 30, which constitute the motor stator 32.

The motor rotor 30 is hermetically and liquid-tight isolated from the motor stator 32 by a metal can 40. Radially between the motor rotor 30 and the motor stator 32, a cylinder body 44 of the split pot 40 is arranged in the cylindrical magnetic gap between the motor stator 32 and the motor rotor 30th lies. The containment shell 40 has an annular pot bottom 42 adjoining the pump-remote longitudinal end of the motor rotor 30. Between the motor section 14 and the control section 16 there is provided a plastic partition wall 50 arranged in a transverse plane, which forms a fluid-tight separation of the motor section 14 from the control section 16 defined by an electronic motor control 71 in a control room 70. The plastic partition wall 50 is an integral part of a plastic housing body 18, which is formed substantially cylindrical and the motor stator 32 and the control chamber 70 radially surrounds.

The plastic partition wall 50 has a heat transfer opening 64, which is extended by a sleeve body 60 axially beyond the axial thickness of the partition 50 on both sides, so that on the proximal side a proximal collar 63 and on the distal side a distal collar 62nd is realized. The elongate heat transfer opening 64 formed in this way is completely filled with a heat conductor 66, which consists of a cured Wärmeleitkleber. The thermal adhesive has a good specific thermal conductivity and forms an electrical insulator.

The motor controller 71 in the control room 70 has a board 73 lying in a transverse plane, which carries the electronic components, which also include a plurality of power semiconductors 72. The power semiconductors 72 are arranged on the distal side of the circuit board 73, ie on the side of the circuit board 73 facing away from the dividing wall 50. The power semiconductors 72 are heaped and concentrated in a small area, in axial alignment with the heat conductor 66.

In the area of the power semiconductors 72, the circuit board 73 is repeatedly through-plated with guide elements 74 in the form of metal sleeves or metal pins filled with a heat-conducting compound, so that those of the Power semiconductors 72 heat is conducted via their cooling surfaces and the guide elements 74 to the proximal side of the board 73. On the proximal side of the board 73, a metallic collecting surface 76 is applied, which establishes the thermal connection between the guide elements 74 on the proximal side of the printed circuit board. The heat conductor 66 is thermally connected directly to the collecting surface 76 such that overall a low thermal resistance is realized.

Claims

Electric motor vehicle coolant pump (10) with

a pump rotor (20),

a motor section (14) having a permanent magnet motor rotor (30), a motor coil (33) having motor stator (32) and a split pot (40), the motor stator (32) liquid-tight from the motor rotor (30) separates, and

a control section (16) having a control room (70) in which the engine controller (71) is arranged, wherein

the control chamber (70) is separated from the motor section (14) by a plastic partition wall (50) lying substantially in a transverse plane,

the partition wall (50) has a heat transfer opening (64) in which a heat conductor (66) is arranged, with its one longitudinal end in heat-conducting contact with the containment shell (40) and with its other longitudinal end in heat-conducting contact with the motor control (71) stands, and

the specific thermal conductivity of the heat conductor (66) is higher than the specific thermal conductivity of the partition wall plastic.

An automotive electric motor coolant pump (10) according to claim 1, wherein said heat transfer port (64) is formed by a sleeve body (60) whose axial length is substantially equal to said sleeve body (60) axial distance between the containment shell (40) and the engine control (71) corresponds.

An automotive electrical coolant pump (10) according to any one of the preceding claims, wherein the heat conductor (66) is formed by a thermal adhesive which completely seals the heat transfer port (64).

4. Electric motor vehicle coolant pump (10) according to one of the preceding claims, wherein the heat conductor (66) is formed by a solid.

5. An automotive electrical motor coolant pump (10) according to any one of the preceding claims, wherein the heat conductor (66) is an electrical insulator.

An automotive electrical coolant coolant pump (10) according to any one of the preceding claims, wherein the plastic partition wall (50) forms the only separation between the motor coils (33) and the control room (70).

7. An automotive electrical motor coolant pump (10) according to any one of the preceding claims, wherein the plastic partition wall (50) is an integral part of a plastic housing body (18) surrounding the motor stator (32) and / or the control chamber (70) radially ,

8. Electric motor vehicle coolant pump (10) according to one of the preceding claims, wherein the gap pot (40) consists of metal. Electric motor vehicle coolant pump (10) according to any one of the preceding claims, wherein the gap pot (40) has a substantially in a transverse plane pot bottom (42) which is in heat-conducting contact with the heat conductor (66) directly

Electric motor vehicle coolant pump (10) according to one of the preceding claims, wherein the motor controller (71) is arranged on a transverse plane in a board (73) and power semiconductor (72) which directly or via guide elements (74) thermally conductively connected to the heat conductor (66) are connected.

An automotive electrical motor coolant pump (10) as claimed in any one of the preceding claims, wherein the vanes (74) are formed by metal sleeves and / or metal pins which fit into the board (73).