Pump arrangement

Abstract

Pump arrangement (1), comprising: - a pump (6) with at least one pump rotor, and - an electric motor (2) comprising a stator (16) and a rotor (4), wherein the rotor (4) of the electric motor (2) is firmly connected to the at least one pump rotor via a toothing and forms a rotor unit, wherein the pump (6) is designed as a gerotor pump with an external gear (15) and an internal gear (17) meshing therewith, wherein the external gear (15) is firmly connected as a pump rotor to the rotor (4) of the electric motor (2), and wherein one or more permanent magnets (14) are arranged in or on the rotor (4), characterized in that the rotor (4) comprises an annular arrangement of permanent magnets (14) which are angularly spaced from one another and are held on a frame (29), wherein a radial outer side of the outer gear (15) has ribs (30) aligned in the axial direction, between which spaces for receiving the permanent magnets (14) on the frame (29) of the rotor (4) are formed in this way.

Description

[0001] The most commonly used electric motor in the automotive sector is the radial, brushless DC motor. This motor type is used in a wide range of automotive products, for example, as actuators for drive elements, control units, and pump drives for cooling and actuating functions. For example, a radial, brushless DC motor can be used to drive a volumetric pump (gerotor pump) for various applications (oil cooling, hydraulic actuating functions).

[0002] US 5,145,329 A discloses a homoplanar brushless electric rotor comprising a housing assembly defining a substantially closed cavity and a fluid inlet port. Inner and outer gerotor pump gears are eccentrically arranged for relative rotation within the cavity, whereby a working fluid received at the inlet port at a low pressure is discharged from the outlet port at a high pressure. A plurality of alternately radially polarized, circumferentially aligned permanent magnets are carried by one of the pump gears for rotation therewith. A stator having windings circumferentially distributed and axially spaced from the permanent magnets cooperates electromagnetically with them to cause their rotation upon electrical energization of the windings by a drive circuit.

[0003] US Pat. No. 3,874,823 A discloses a compressor with blades that can be reciprocated along a rotor shaft through slots in a rotor under the guidance of stationary guide surfaces on the rotor. The compressor has a cylindrical shell extending around the blades and mounted for rotation with the rotor. An electric motor rotor is provided around the cylindrical shell and attached to the outside of the cylindrical shell.

[0004] DE 692 03 258 T2 discloses an electric pump for circulating a fluid, for example, in the circuit of an internal combustion engine. The pump has a stationary housing defining a fluid collection chamber, a pump impeller rotatably mounted on the stationary housing and provided with pumping elements for the fluid in the chamber, and an electric motor with an induction coil and a rotor, each connected to one of the housing and the pump impeller. The rotor has a number of permanent magnets attached to a second ring of ferromagnetic material, forming an insert embedded in the material of the pump impeller.

[0005] DE 10 2016 224 898 A1 discloses a pump device for an automatic transmission. The pump device comprises an internal gear pump, magnets, and a stator for an electric motor. The internal gear pump comprises a pump housing, an externally toothed pump wheel, and an internally toothed ring gear meshing therewith. The ring gear is electrically driven by being rotationally fixedly connected to the magnets and radially surrounded by the stator. The magnets are arranged radially outside a toothing of the ring gear, and the ring gear is mounted radially relative to the stator by means of a bearing device.

[0006] EP 1 748 533 B1 discloses a permanent magnet rotor with a cylindrical plastic cage. The plastic cage has dovetail-shaped recesses into which permanent magnets are inserted.

[0007] DE 10 2006 017 233 A1 discloses a rotor assembly for an electric machine comprising a magnet carrier for accommodating permanent magnets, which is manufactured as an injection-molded plastic component. The magnet carrier has a cylindrical shape and pockets formed in the magnet carrier that are open toward the outer circumference of the magnet carrier and closed along the inner circumference. Permanent magnets are arranged in the pockets.

[0008] The object of the present invention is to provide an improved pump arrangement.

[0009] The object is achieved according to the invention by the features of claim 1. A pump arrangement according to the invention comprises: - a pump with at least one pump rotor, and - an electric motor comprising a stator and a rotor, wherein the rotor of the electric motor is fixedly connected to the at least one pump rotor via a toothing and forms a rotor unit. The pump is designed as a gerotor pump with an external gear and an internal gear meshing therewith, wherein the external gear, as a pump rotor, is fixedly connected to the rotor of the electric motor and wherein one or more permanent magnets are arranged in or on the rotor. The rotor comprises an annular arrangement of angularly spaced permanent magnets which are held on a frame, wherein a radial outer side of the external gear has ribs aligned in the axial direction, between which spaces are formed in this way for receiving the permanent magnets on the frame of the rotor.

[0010] In the prior art, for transmitting rotary movements from a radial, brushless DC motor to a pump, a shaft is provided on the rotor, which is held in a closely tolerated position by means of bearings, the bearings being held in specially provided receptacles in a housing or bearing carrier or bearing shield.

[0011] Due to the fixed connection of the electric motor rotor to the at least one pump rotor via a toothing and the rotor unit thus formed, a shaft between the motor rotor and a pump rotor can be eliminated. Consequently, a shaft bearing is also eliminated.

[0012] By eliminating bearings, no bearing bracket or bearing shield is required. This reduces the number of individual parts required, making the pump assembly smaller, simpler, and more cost-effective. The reduced number of individual parts simplifies the assembly process, and the pump assembly can be made smaller than with the current state of the art.

[0013] In one embodiment, the electric motor is designed as a radial, brushless DC motor whose rotor is arranged radially inside the stator.

[0014] According to the invention, the pump is designed as a gerotor pump with an external gear and an internal gear meshing therewith, wherein the external gear is firmly connected to the rotor of the electric motor as a pump rotor.

[0015] In one embodiment, one or more permanent magnets are arranged in or on the rotor.

[0016] According to the invention, the rotor comprises an annular arrangement of angularly spaced permanent magnets which are held on a frame.

[0017] According to the invention, a radial outer side of the outer gear has ribs aligned in the axial direction, between which spaces are formed for receiving the permanent magnets.

[0018] In one embodiment, a rotor protection ring is provided for radially receiving the rotor and / or a stator protection ring is provided for radially receiving inside the stator.

[0019] In one embodiment, the rotor protection ring has axially extending slots to engage the ribs of the outer gear so that the rotor, the rotor protection ring, and the outer gear are coupled for common rotation.

[0020] In one embodiment, the rotor protection ring is formed as part of the outer gear and / or the stator protection ring is formed as part of a housing that accommodates the stator.

[0021] In one embodiment, a sensor magnet is arranged in or on the inner gear, wherein a sensor is provided for detecting a magnetic flux caused by the sensor magnet to determine a rotational position and speed of the inner gear.

[0022] In one embodiment, an electronic power supply and control module is further provided, which is electrically connected at least to the stator. Furthermore, the electronic power supply and control module can be connected to an external controller and power supply via an interface, for example, a connector.

[0023] In one embodiment, the electronic power supply and control module is further connected to the sensor.

[0024] In one embodiment, the electronic power supply and control module is arranged in a chamber arranged axially on one side of the pump.

[0025] In one embodiment, the electronic power supply and control module is located to the side of the pump.

[0026] The pump arrangement can be used, for example, for oil cooling or for hydraulic control functions in a vehicle.

[0027] Embodiments of the invention are explained in more detail with reference to the drawings. Fig. 1 a schematic cross-sectional view of a pump arrangement, Fig. 2 a schematic view of an embodiment of a pump arrangement, Fig. 3 a schematic exploded view of the pump arrangement, Fig. 4 is a further schematic exploded view of part of the pump assembly, and Fig. 5 a schematic exploded view of a part of another embodiment of the pump arrangement.

[0028] Corresponding parts are provided with the same reference numerals in all figures.

[0029] Fig. 1 shows a cross-sectional view of a pump assembly 1 comprising a radial, brushless DC motor 2 in a housing 3, for example a die-cast housing, which is also used, for example, as a heat sink for electronic components. The DC motor 2 comprises a permanent magnet rotor 4 running within a stator 16, which is attached to a shaft 5 that drives a pump 6, for example a gerotor pump. The shaft 5 is mounted in the housing 3 by means of two bearings 7.1, 7.2, for example a bearing 7.1 held in the housing 3 by means of a press fit on one side and a bearing 7.2 held in a bearing carrier 8 on the other side. The pump 6 is enclosed between the housing 3 of the DC motor 2 and a pump housing 9 flanged thereto.An electronic power supply and control module 10 is attached to the housing 3 and includes a connector 11 for power supply and communication, as well as a sensor for determining the rotational position and speed of the shaft 5 via a sensor magnet 12. The electronic power supply and control module 10 is covered with a cover 13, for example, made of sheet metal. All contact points between components where substances could be exchanged between the environment and the device interior are provided with seals, for example, wet seals or O-rings.

[0030] Fig. Figure 2 is a schematic view of one embodiment of a pump assembly 1 comprising a radial, brushless DC motor 2 with an integrated pump 6. The DC motor 2 is arranged in a housing 3, for example a die-cast housing, which can also be used, for example, as a heat sink for electronic components. The DC motor 2 comprises a permanent magnet rotor 4 running within a stator 16. The rotor 4 of the DC motor 2 is connected for common rotation to an external gear 15 of the pump 6, which is designed as a gerotor pump. The pump functionality is achieved by means of the magnetic flux from the stator 16 to permanent magnets 14 arranged in or on the external gear 15, wherein the external gear 15 rotates an internal gear 17 to pump a working fluid.A sensor magnet 12 is arranged in the inner gear 17 to cause a magnetic flux in a sensor in an electronic power supply and control module 10 for determining the rotational position and speed of the inner gear 17. The electronic power supply and control module 10 is attached to a pump cover 13 and has a connector 11 for power supply and communication, as well as a sensor for determining the rotational position and speed of the inner gear 17 via the sensor magnet 12. The pump cover 13 separates the electronic power supply and control module 10 from the pump 6. The electronic power supply and control module 10 is covered with a further cover 26, for example made of sheet metal.All contact points between components where substances could be exchanged between the environment and the interior of the device may be provided with seals 21, for example wet seals or O-rings.

[0031] Unlike the Fig. The embodiment shown in Figure 1 requires the Fig. In the embodiment shown in Figure 2, neither the shaft 5 nor the corresponding bearings 7.1, 7.2 are required, since the stator 16, the rotor 4, the outer gear 15, and the inner gear 17 are arranged in one and the same housing 3, which is closed by the pump cover 13, whereby the stator 16 is sealed from the pump 6 and the working fluid contained therein. Two connections 23 of the pump 6 are provided in the housing 3, which can serve as inlet and outlet.

[0032] Fig. 3 is a schematic exploded view of the pump assembly 1. Shown are the housing 3, which is closed at the bottom except for the connections 23, the outer gear 15 with the inner gear 17 arranged therein, and the sensor magnet 12. The rotor 4 comprises an annular arrangement of angularly spaced permanent magnets 14, which can be held on a frame 29. A radial outer side of the outer gear 15 is divided by axially aligned ribs 30, between which spaces are created in this way, which are provided for receiving the permanent magnets 14. The rotor 4 is thus toothed with the outer gear 15. A rotor protection ring 27 is designed to receive the rotor 4 and has slots running in the axial direction to engage the ribs 30 of the outer gear 15, so that the rotor 4, the rotor protection ring 27, and the outer gear 15 rotate together.

[0033] The stator 16 can be formed at least approximately in the shape of a hollow cylinder, such that a stator protection ring 28 can be accommodated within it, within which the rotor 4 can be accommodated with the rotor protection ring 27 and the outer gear 15. The stator protection ring 28 can be designed to seal against the housing 3 and against the pump cover 13, so that the stator 16 is protected from fluids located within the stator protection ring 28. Also shown are the electronic power supply and control module 10, the cover 26, the connector 11, and a number of screws 22 for mounting the pump assembly 1.

[0034] A sealing ring 21 may be provided between the pump cover 13 and the housing 3. Furthermore, a sealing ring 21 may be provided between the pump cover 13 and the cover 26. Two further sealing rings 21 may be provided between the stator 16 and the housing 3 on one axial side of the stator 16 and between the stator 16 and the pump cover 13 on an opposite axial side of the stator 16.

[0035] Fig. 4 is another schematic exploded view of part of the pump assembly 1.

[0036] The pump assembly 1 can be divided into the following subunits: - a rotor unit comprising the outer gear 15, the rotor 4 with the permanent magnets 14 and the frame 29, as well as the rotor protection ring 27; - a stator unit comprising the stator 16 with a metal core and windings, for example copper windings, and the stator protection ring 28; - an inner pump unit comprising the inner gear 17 with a recess for the sensor magnet 12, as well as the sensor magnet 12.

[0037] To assemble the pump assembly 1, the rotor 4 is connected to the outer gear 15 of the pump 6 by engaging the permanent magnets 14 with the spaces between the ribs 30, for example, by pressing them in. The rotor protection ring 27 is then placed over the rotor 4.

[0038] The stator protection ring 28 is inserted into the stator 16, for example, by pressing it in. The function of the rotor protection ring 27 and the stator protection ring 28 is to create a separation area that prevents contact between the stator 16, for example, an overmolding of the stator 16, and the permanent magnets 14 of the rotor 4, so that they do not wear due to friction.

[0039] Fig. 5 is a schematic exploded view of part of another embodiment of the pump assembly 1.

[0040] The embodiment shown is similar to that shown in the Fig. 2 to 4. However, the rotor protection ring 27 and the stator protection ring 28 are not formed as separate parts. Instead, the rotor protection ring 27 is formed as part of the outer gear 15, and the stator protection ring 28 is formed as part of the housing 3. Therefore, the slots extending in the axial direction can be omitted in the rotor protection ring 27.

[0041] The assembly of this embodiment is simplified accordingly: The rotor 4 is connected to the outer gear 15 of the pump 6 by inserting the permanent magnets 14 into the rotor protection ring 27 and engaging them, for example by pressing them, with the spaces between the ribs 30.

[0042] The stator 16 is inserted into the housing 3, for example by pressing, whereby in this way the stator protection ring 28 is simultaneously inserted into the stator 16.

[0043] The inner gear 17 is inserted into the outer gear 15.

[0044] The Fig. The embodiment shown in Figure 5 is therefore simpler than the one shown in Fig. 2 to 4 and requires fewer individual parts. Furthermore, at least one sealing ring 21 can be omitted.

[0045] In embodiments not shown, the sensor magnet 12 and the sensor can be omitted.

[0046] In embodiments not shown, a vane pump or a centrifugal pump may be provided instead of a gerotor pump.

[0047] In all embodiments, the cover 26 can be omitted. Instead, for example, the electronic power supply and control module 10 can be arranged in a potting. List of reference symbols 1 Pump arrangement 2 DC motors 3 housings 4 Rotor 5 Wave 6 Pump 7.1 Warehouse 7.2 Warehouse 8 bearing supports 9 Pump housing 10 electronic power supply and control module 11 connectors 12 Sensor magnet 13 Pump cover 14 Permanent magnet 15 outer gear 16 Stator 17 inner gear 21 Sealing ring, gasket 22 screw 23 Connection 26 Cover 27 Rotor protection ring 28 Stator protection ring 29 scaffolding 30 ribs

Claims

[1] Pump arrangement (1), comprising: - a pump (6) with at least one pump rotor, and - an electric motor (2) comprising a stator (16) and a rotor (4), wherein the rotor (4) of the electric motor (2) is firmly connected to the at least one pump rotor via a toothing and forms a rotor unit, wherein the pump (6) is designed as a gerotor pump with an external gear (15) and an internal gear (17) meshing therewith, wherein the external gear (15) is firmly connected as a pump rotor to the rotor (4) of the electric motor (2), and wherein one or more permanent magnets (14) are arranged in or on the rotor (4), characterized byin that the rotor (4) comprises an annular arrangement of angularly spaced permanent magnets (14) which are held on a frame (29), wherein a radial outer side of the outer gear (15) has ribs (30) aligned in the axial direction, between which spaces for receiving the permanent magnets (14) on the frame (29) of the rotor (4) are formed in this way. [2] Pump arrangement (1) according to claim 1, characterized by that the electric motor (2) is designed as a radial, brushless DC motor (2), the rotor (4) of which is arranged radially inside the stator (16). [3] Pump arrangement (1) according to one of the preceding claims, characterized by that a rotor protection ring (27) is provided for radially receiving the rotor (4) and / or wherein a stator protection ring (28) is provided for radially receiving in the interior of the stator (16). [4] Pump arrangement (1) according to claim 3, characterized bythat the rotor protection ring (27) has axially extending slots to engage the ribs (30) of the outer gear (15) so that the rotor (4), the rotor protection ring (27) and the outer gear (15) are coupled for common rotation. [5] Pump arrangement (1) according to claim 3, characterized by , that the rotor protection ring (27) is formed as part of the outer gear (15) and / or the Stator protection ring (28) is formed as part of a housing (3) which accommodates the stator (16). [6] Pump arrangement (1) according to one of claims 3 to 5, characterized by that a sensor magnet (12) is arranged in or on the inner gear (17), wherein a sensor is provided for detecting a magnetic flux caused by the sensor magnet (12) for determining a rotational position and speed of the inner gear (17).

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