Electronically commutated motor for a liquid pump

Abstract

The invention relates to an electronically commutated motor (1) for a liquid pump, in particular a water pump, comprising a permanent magnet rotor (2) which is fastened to a shaft (3), the shaft (3) being mounted within two bearings (4) and being operatively connected to a pump impeller (5), a stator (6) with a winding (7) which is fastened to insulating elements (8) provided on the end face of the stator (6), a containment shell (9) which separates a wet space from a dry space and in which the permanent magnet rotor (2) is accommodated, a pump head (10) with a suction (11) and pressure connection (12), and a motor housing (13) in which the permanent magnet rotor (2), the wound stator (6), the containment shell (9), and electronics (14) are accommodated, a bearing plate (15) being arranged between the pump impeller (5) and the containment shell (9),closes the can (9) at the front and wherein the bearing plate (15) accommodates a bearing (4) in a bearing receptacle (16).,

Description

[0001] The invention relates to an electronically commutated motor for a liquid pump, in particular a water pump.

[0002] In liquid pumps of this type, especially water pumps, it is common practice to mount the rotor axially and radially in a so-called tripod, which is incorporated into the pump head. Every movement of the rotor is transmitted to the tripod in the pump head. The tripod is designed with a shaft bearing and three spokes that are connected to the pump head. The direct mechanical connection of the rotor rotating in the medium via the axle, which is fixed in the tripod of the pump head, can have a negative acoustic impact on the suitability for the respective application with regard to its requirements.

[0003] The object of the present invention is to propose an electronically commutated motor for a liquid pump, which ensures a low-complexity and cost-effective sealing of a dry space from a wet space, an integration into an application-specific application with or without the use of a pump head, and a radial and axial bearing of the rotor.

[0004] This object is achieved by the features according to claim 1. An electronically commutated motor for a liquid pump, in particular a water pump, comprises - a permanent magnet rotor mounted on a shaft, the shaft being supported within two bearings and being operatively connected to a pump impeller, - a stator with a winding which is fixed to insulating elements on the front side of the stator, - a containment shell that separates a wet space from a dry space and in which the permanent magnet rotor is housed, - a pump head with a suction and pressure port and - a motor housing housing the permanent magnet rotor, the wound stator, the containment shell, and electronics. A bearing plate is arranged between the pump impeller and the containment shell, closing the containment shell at the front. The bearing plate accommodates a bearing in a bearing recess. The bearing is, in particular, injection-molded into the bearing recess. However, it is also conceivable for the bearing to be mounted in the bearing recess. The bearing is preferably a graphite bearing.

[0005] An advantage of the device according to the invention is that the electronically commutated motor for a liquid pump can be supplied with or without a pump head, allowing it to be integrated into application-specific applications, such as a thermal management module. The bearing plate eliminates the need for a pump head with a tripod in which the shaft is mounted. The shaft, which is operatively connected to the permanent magnet rotor, is supported in the bearing plate in both axial and radial directions.

[0006] In one embodiment, the bearing plate with enclosed bearing has a passage for the shaft and at least one fluid flow hole. At least one fluid flow hole directs the fluid into the wet space, and at least one fluid flow hole directs the fluid out of the wet space. This allows for the generation of an active fluid flow.

[0007] Furthermore, it can be provided that a plurality of contours are formed on the underside of the bearing plate, which correspond to mating contours on the containment shell. This ensures complementary assembly of the components. Small contours on the underside of the bearing plate serve to optimize injection molding. Long or larger contours on the underside of the bearing plate serve as a support surface for mating contours on the containment shell and are preferably bonded to them.

[0008] An advantageous design provides for at least one anti-twist device on the bearing plate. This enables precise mounting of the bearing plate on the containment shell.

[0009] A further advantageous design provides for the containment shell to have axial cooling fins on its outer circumference and radial cooling fins in the base area. The radial cooling fins in the base area also serve to stiffen or stabilize the base area and are formed by material accumulations. The axial cooling fins serve to stiffen the containment shell and can also serve as a secondary cooling element.

[0010] The containment shell may be provided with a mounting location for the bearing in the base area. The bearing can be injected or inserted into the mounting location, or secured in another manner known to those skilled in the art.

[0011] It can further be provided that the containment shell has a radially surrounding collar on its outer circumference in some regions, which is divided into two levels. In particular, at least one screw eye is formed on the first level of the collar, to which the containment shell is fastened between the pump head and the motor housing. Furthermore, at least one fastening projection can be formed on the first level of the collar, to which the containment shell is additionally fastened to the motor housing by means of a dome. The dome is designed here to be complementary to the fastening projection and can be in the form of a pin or other shapes familiar to those skilled in the art. The containment shell can be connected to the motor housing in at least one fastening projection by means of the dome by hot caulking, gluing, or other connecting methods known to those skilled in the art from the field of positive-locking, material-locking, or force-locking connecting methods.

[0012] Furthermore, a radially encircling toothed belt-like contour, on which a sealing means is accommodated, can be formed on the second plane, and at least one centering element can be formed on the second plane. The toothed belt-like contour advantageously serves to optimize injection molding, as it allows for savings in injection molding material at the second plane. The at least one centering element serves to center the bearing plate on the motor housing and allows for an air gap between the stator and the motor housing. The at least one sealing means lies axially against the toothed belt-like contour.

[0013] In a preferred embodiment, the containment shell has mating contours on the axial end face and a radially circumferential edge in the axial direction, which limits the seating of the bearing plate on the containment shell. The radial diameter of the bearing plate is adapted to the radial diameter of the containment shell opening, in particular, it is always substantially smaller than the radial diameter of the containment shell opening. Thus, the bearing plate is only attached to the containment shell; an additional or separate attachment to the motor housing or pump head is not necessary.

[0014] It can further be provided that the bearing plate is attached to the containment shell by means of the contours and counter-contours.

[0015] An advantageous embodiment of the invention provides for the bearing plate to be firmly bonded to the containment shell using a suitable welding process. Laser transmission welding is particularly preferred for this purpose. However, it is also conceivable to use an adhesive bonding process. Form-fit joining methods are also suitable.

[0016] The features and advantages of the electronically commutated motor for a liquid pump of the present invention are explained in more detail below using exemplary embodiments with reference to the drawings. Fig. 1 an exemplary overview of an electronically commutated motor for a liquid pump according to an embodiment, Fig. 2 a plan view of the top of the bearing plate; Fig. 3 a plan view of the underside of the bearing plate; Fig. 4 a top view of the containment shell; Fig. 5 a representation of the axial end face of the containment shell; Fig. 6 a top view of the attached bearing plate on the containment shell.

[0017] Fig. 1 shows an exemplary overview of an electronically commutated motor (1) for a liquid pump, in particular a water pump, comprising a permanent magnet rotor (2) which is fastened to a shaft (3), wherein the shaft (3) is mounted within two bearings (4) and is operatively connected to a pump impeller (5), a stator (6) with a winding (7) which is fastened to insulating elements (8) provided on the end face of the stator (6), a containment shell (9) which separates a wet space from a dry space and in which the permanent magnet rotor (2) is accommodated, a pump head (10) with a suction (11) and pressure port (12), and a motor housing (13) in which the permanent magnet rotor (2), the wound stator (6), the containment shell (9), and electronics (14) are accommodated. A bearing plate (15) is arranged between the pump impeller (5) and the containment shell (9).The bearing plate (15) closes the containment shell (9) at the front and accommodates a bearing (4) in a bearing holder (16).

[0018] Fig. Figure 2 shows a top view of the bearing plate (15). The bearing plate (15) has a passage (17) for the shaft (3) and at least one fluid flow hole (18). To prevent the bearing plate (15) from twisting during assembly on the containment shell (9) (not shown here), an anti-twist device (22) is formed in the bearing plate (15).

[0019] Fig. Figure 3 shows a plan view of the underside (19) of the bearing plate (15). A plurality of contours (20) are formed on the underside (19), which correspond to counter-contours (21) (not shown here) on the containment shell (9) (not shown here). At the center of the bearing plate (15), it accommodates a bearing (4) (not shown here) in a bearing receptacle (16).

[0020] Fig. 4 shows a top view of the containment shell (9), which has axial cooling fins (23) on its outer circumference and radial cooling fins (24) in the bottom area (see Fig. 5). On its outer circumference, the containment shell (9) has a radially encircling collar (26) in some regions, which is divided into two levels (27, 28). At least one screw eye (29) is formed on the first level (27) of the collar (26), to which the containment shell (9) is fastened between the pump head (10) (not shown here) and the motor housing (13) (not shown here). At least one radially encircling toothed belt-like contour (30) is formed on the second level (28), on which a sealing means (31) (not shown here) is received. In addition, at least one centering element (32) is formed on the second level (28). Furthermore, at least one fastening projection (34) can be formed on the first level (27) of the collar (26), to which fastening projection the containment shell (9) is additionally fastened to the motor housing (13) by means of a dome (not shown here).

[0021] Fig. Figure 5 shows a representation of the axial end face of the containment shell (9). The containment shell (9) has radial cooling fins (24) in the base area and a receiving location (25) for the bearing (4) (not shown here). On the axial end face, the containment shell (9) has the mating contours (21) and a radially circumferential edge (33) in the axial direction, which limits the reception of the bearing plate (15) on the containment shell (9). The bearing plate (15) is fastened to the containment shell (9) by means of the contours (20) on the bearing plate (15) and the mating contours (21) on the containment shell (9). Furthermore, at least one fastening projection (34) can be formed on the first plane (27) of the collar (26), to which the containment shell (9) is additionally fastened to the motor housing (13) by means of a dome (not shown here).

[0022] Fig.6 shows a top view of the attached bearing plate (15) on the containment shell (9). The containment shell (9) is inserted into the stator (6), which has insulating elements (8) on its end face. The containment shell (9) is fastened between the pump head (10) (not shown here) and the motor housing (13) (not shown here) by means of the at least one screw eye (29). A sealing means (31) is received on the toothed belt-like contour (30). In addition, a centering means (32) is formed on the second plane (28). On the axial end face of the containment shell (9), a radially circumferential edge (33) is formed in the axial direction, which delimits the reception of the bearing plate (15) on the containment shell (9). A sealing means (31) is arranged on the radially circumferential edge (33), which represents an interface to an application. In addition, the radially surrounding edge (33) serves as a centering surface for the pump head (10) (not shown here) and as a centering and sealing function on the application side.The bearing plate (15) is integrally connected to the containment shell (9) using a suitable welding process. However, other fastening options for the bearing plate (15) to the containment shell (9) are also conceivable, which are known to those skilled in the art. The circumferential edge (33) limits the radial diameter of the bearing plate (15) so that it is substantially smaller than or corresponds to the diameter of the containment shell (9). This ensures optimal sealing of the bearing plate (15) to the containment shell (9). Furthermore, at least one fastening projection (34) can be formed on the first plane (27) of the collar (26), to which fastening projection the containment shell (9) is additionally fastened to the motor housing (13) by means of a dome (not shown here). List of reference symbols 1 Electronically commutated motor 2 permanent magnet rotor 3 Wave 4 camps 5 Pump impeller 6 Stator 7 winding 8 Insulating element 9 containment shell 10 Pump head 11 suction nozzle 12 pressure ports 13 Engine housing 14 Electronics 15 bearing plate 16 Bearing recording 17 passage 18 Fluid flow hole 19 Bottom 20 contours 21 counter contours 22 Anti-twist device 23 axial cooling fins 24 radial cooling fins 25 reception center 26 collars 27 first level 28 second level 29 screw eye 30 toothed belt-like contour 31 Sealant 32 Centering element 33 rand 34 Mounting projection

Claims

[1] Electronically commutated motor (1) for a liquid pump, in particular a water pump, comprising - a permanent magnet rotor (2) which is mounted on a shaft (3) with the shaft (3) being mounted within two bearings (4) and being operatively connected to a pump impeller (5), - a stator (6) with a winding (7) which is fastened to insulating elements (8) on the front side of the stator (6), - a containment shell (9) which separates a wet space from a dry space and in which the permanent magnet rotor (2) is accommodated, - a pump head (10) with a suction (11) and pressure port (12) and - a motor housing (13) in which the permanent magnet rotor (2), the wound stator (6), the containment shell (9) and an electronics unit (14) are accommodated, - wherein a bearing plate (15) is arranged between the pump impeller (5) and the containment shell (9), closes the containment shell (9) at the front and wherein the bearing plate (15) accommodates a bearing (4) in a bearing receptacle (16). [2] Electronically commutated motor according to claim 1, wherein the bearing plate (15) with enclosed bearing (4) has a passage (17) for the shaft (3) and at least one fluid flow hole (18). [3] Electronically commutated motor according to claim 1 or 2, wherein a plurality of contours (20) are formed on the underside (19) of the bearing plate (15), which contours correspond to counter contours (21) on the containment shell (9). [4] Electronically commutated motor according to one of the preceding claims, wherein at least one anti-rotation device (22) is formed on the bearing plate (15). [5] Electronically commutated motor according to claim 1, wherein the containment shell (9) has axial cooling fins (23) on its outer circumference and radial cooling fins (24) in the bottom region. [6] Electronically commutated motor according to claim 5, wherein the containment shell (9) has a receiving point (25) for the bearing (4) in the bottom region. [7] Electronically commutated motor according to one of the preceding claims, wherein the containment shell (9) has on its outer circumference in some regions a radially encircling collar (26) which is divided into two planes (27, 28). [8] Electronically commutated motor according to claim 7, wherein at least one screw eye (29) is formed on the first plane (27) of the collar (26), to which the containment shell (9) is fastened between the pump head (10) and the motor housing (13). [9] Electronically commutated motor according to claim 7 or 8, wherein at least one fastening projection (34) is formed on the first plane (27) of the collar (26), to which the containment shell (9) is additionally fastened to the motor housing (13) by means of a dome. [10] Electronically commutated motor according to claim 7, wherein a radially encircling toothed belt-like contour (30) is formed on the second plane (28), on which contour a sealing means (31) is received and wherein at least one centering element (32) is formed on the second plane (28). [11] Electronically commutated motor according to one of the preceding claims, wherein the containment shell (9) has the counter contours (21) on the axial end face and a radially circumferential edge (33) in the axial direction, which limits the receptacle of the bearing plate (15) on the containment shell (9). [12] Electronically commutated motor according to one of the preceding claims, wherein the bearing plate (15) is fastened to the containment shell (9) by means of the contours (20) and counter-contours (21). [13] Electronically commutated motor according to one of the preceding claims, wherein the bearing plate (15) is integrally connected to the containment shell (9) by means of a suitable welding process.

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