ELECTRIC COOLANT PUMP

Abstract

The invention relates to an electric coolant pump comprising a pump housing, a rotating conveying element for accelerating the coolant, a pump shaft passing through the pump housing and on which the conveying element is mounted, an electric motor for driving the pump shaft; and a control circuit. The conveying element is arranged in a pump chamber formed by the pump housing and a spiral lid. The electric motor is arranged in a motor chamber formed by the pump housing and motor lid. Furthermore, a control circuit chamber is formed in the pump housing, for the control circuit. The control circuit chamber has an opening through which the control circuit can be inserted into the control circuit chamber.

Claims

1. An electric coolant pump including: a pump housing; a rotating conveying element for accelerating the coolant to be conveyed; a pump shaft, passing through the pump housing, on which the conveying element is mounted; an electric motor for driving the pump shaft; and a control circuit; wherein: the conveying element is arranged in a pump chamber formed by the pump housing and a spiral lid; the electric motor is arranged in a motor chamber formed by the pump housing and a motor lid; in the pump housing, a control circuit chamber is provided, inside of which the control circuit is arranged; and the control circuit chamber has an opening, through which the control circuit is insertable into the control circuit chamber.

2. The electric coolant pump according to claim 1, wherein the control circuit chamber is arranged in an axial direction of the pump shaft between the pump chamber and the motor chamber, and the insertion direction is oriented perpendicularly with respect to the axial direction of the pump shaft.

3. The electric coolant pump according to claim 1, wherein the control circuit chamber is provided immediately adjacent to the pump chamber.

4. The electric coolant pump according to claim 1, wherein the control circuit is fixed by means of a thermal paste or a thermal conductive pad in the control circuit chamber, particularly in the direction of the pump chamber.

5. The electric coolant pump according to claim 1, wherein the control circuit chamber extends in a U-shaped manner around the pump shaft.

6. The electric coolant pump according to claim 1, wherein the control circuit is arranged on a rectangular or U-shaped circuit board.

7. The electric coolant pump according to claim 1, wherein the opening of the control circuit chamber is closed by a lid.

8. The electric coolant pump according to claim 7, wherein, in the lid, a connector plug is provided for the control circuit.

9. The electric coolant pump according to claim 1, wherein, adjacent to the control circuit chamber, a leakage space for receiving escaping coolant is provided in the pump housing.

10. The electric coolant pump according to claim 1, wherein a winding of the electric motor is contactable by insulation-displacement connections when inserting the control circuit into the control circuit chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention will be explained in more detail hereinunder by means of an exemplified embodiment with the aid of the accompanying Figures. In the drawing:

[0017] FIG. 1 shows a perspective view of an exemplified embodiment of the electric coolant pump;

[0018] FIG. 2 shows an exploded perspective view of the electric coolant pump of FIG. 1;

[0019] FIG. 3 shows a side view of the electric coolant pump of FIG. 1 without a lid for the control circuit chamber;

[0020] FIG. 4 shows a cross-sectional view through the pump housing; and

[0021] FIG. 5 shows a cross-sectional view through the pump housing along the sectional plane A-A in FIG. 4.

[0022] The structure of an exemplified embodiment of the electric coolant pump in accordance with the invention is described hereinunder with reference to the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

[0023] The electric coolant pump 1 illustrated in FIGS. 1 to 3 serves to convey a coolant in a coolant circuit not illustrated in more detail. This coolant circuit can serve e.g. for cooling of an internal combustion engine of a motor vehicle and can consist substantially of cooling ducts through which the coolant is supplied to the components to be cooled and then to a heat sink (e.g. radiator). In the simplest case, the coolant can be e.g. water or a dielectric cooling liquid, to which metal corrosion-inhibiting constituents are added.

[0024] The electric coolant pump 1 comprises a pump housing 2 as a main component. In the described embodiment, the pump housing 2 is produced from a metallic material, in particular aluminium. A pump shaft 4 is mounted centrally in the pump housing 2 by means of a bearing 3. The pump shaft 4 therefore passes through the pump housing 2. A pump impeller 5 is mounted in a first axial end region of the pump shaft 4. The pump impeller 5 serves as a rotating conveying element for acceleration of the coolant to be conveyed. A rotor 6 is mounted in a second axial end region of the pump shaft 4 on the opposite side of the pump housing 2. Together with the stator 7, the rotor 6 forms an electric motor 8 for driving the pump shaft 4.

[0025] Jointly with a spiral lid 9, the pump housing 2 forms a pump chamber in which the pump impeller 5 is arranged. A seal 10 between the pump housing 2 and spiral lid 9 ensures a connection between these components which is as liquid-tight as possible. On the opposite side of the pump housing 2, and together with a motor lid 11, the pump housing 2 in turn forms a motor chamber in which the electric motor 8 is arranged.

[0026] Furthermore, a control circuit chamber 12 is formed within the pump housing 2. As seen in the axial direction of the pump shaft 4, this control circuit chamber 12 is arranged between the pump chamber and the motor chamber. The control circuit chamber 12 is formed in a substantially shaft-like manner and has a rectangular opening 13. A control circuit 14 for the electric coolant pump 1, i.e. more precisely for the electric motor 8, is arranged in this control circuit chamber 12. The insertion direction, in which the control circuit 14 is inserted into the control circuit chamber 12, is oriented perpendicularly (orthogonally) to the axial direction of the pump shaft 4.

[0027] The control circuit 14 is designed as an ECU and arranged on a U-shaped circuit board which has been inserted into the control circuit chamber 12 through the opening 13. The opening 13 is closed by means of a lid 15. Connector plugs 16 are formed on the lid.

[0028] During operation of the electric coolant pump 1, the pump impeller 5 is driven by the electric motor 8 operated by means of the control circuit 14. The coolant located in the pump chamber is accelerated by the pump impeller 5 and exits through the pump outlet 17 formed on the spiral lid 9. At the same time, coolant enters the pump chamber from the pump inlet 18 also formed on the spiral lid 9.

[0029] FIG. 4 shows a cross-sectional view through the pump housing 2, wherein the sectional plane coincides with the middle axis of the pump shaft 4. FIG. 5 shows a cross-sectional view through the pump housing 4 along the sectional plane A-A in FIG. 4. In the centre of the pump housing 2, a rotationally symmetrical aperture 19 for reception of the bearing 3 and of the pump shaft 4 is provided. The control circuit chamber 12 is formed in a U-shape around this aperture 19. In the axial direction of the pump shafts 4, the control circuit chamber 12 is separated by intermediate walls of the pump housing 2 from the pump chamber on one side (at the top in FIG. 4) and from the motor chamber on the other side (at the bottom in FIG. 4) and so, all in all, three separate chambers (control circuit chamber 12, pump chamber, motor chamber) are provided. The control circuit 14 is mounted in the control circuit chamber 12 by means of thermal conductive pads (not illustrated in more detail in the Figures) on the intermediate wall of the pump housing 2 facing the pump chamber.

[0030] As described above, the control circuit chamber 12 surrounds the pump shaft 4 in a U-shape. A leakage space 20 is formed in the spatial region around the pump shaft 4 in which the control circuit chamber 12 is not arranged. This leakage space 20 serves to receive coolant exiting in the region of the aperture 19.

[0031] Through the opening 13, the insertion of the control circuit 14 is also possible only after mounting of the remaining components such as bearing 3, pump shaft 4, pump impeller 5, rotor 6, stator 7, spiral lid 9, seal 10 and motor lid 11. This simplifies assembly, inter alia also because no ESD protection for the complete assembly is required. Furthermore, the adaptability and variability of the electric coolant pump 1 are increased since individually adapted control circuits 14 can be used independently of the remaining components of the electric coolant pump 1 in a later assembly step. Finally, maintenance and repair work on the control circuit 14 is facilitated since this can easily be removed from the control circuit chamber 12 after the lid 15 is opened.

[0032] The formation of the control circuit on a U-shaped circuit board together with the U-shaped control circuit chamber 12 ensures effective use of the available installation space. The integration of the leakage space 20 additionally increases the usage of the installation space.

[0033] Fixing the control circuit 14 directly to the intermediate wall of the pump housing 2 facing the pump chamber by means of thermal conductive pads or thermal conductive paste achieves particularly good thermal coupling to the coolant flowing through the pump chamber. In this way, the coolant can bring about a cooling effect on the control circuit 14.

[0034] The Figures of the drawings do not show an embodiment in which, during insertion of the control circuit 14 into the control circuit chamber 12, a winding of the electric motor 8 is contacted by insulation-displacement connections.

[0035] In the embodiment described above, the rotating conveying element is designed as a pump impeller 5 in order to accelerate the coolant to be conveyed. However, depending on the type of pump, another conveying element can also be used instead of the pump impeller 5.