Electric motor type drive for motor vehicles

Abstract

This invention relates to an electric motor drive (4) for motor vehicles, particularly a fan drive, comprising: an electric motor (8) having a rotor (20) supported in a rotatable manner and a stator (22) having laminations (32) forming a stator yoke (34) of the stator (22) and stator teeth (36) radially extending from the stator yoke, wherein stator windings (40) are carried on the stator teeth (36); and an electrically conductive cover (50). The cover is used to influence and / or shield the interfering electromagnetic field generated during the operation of the electric motor, wherein the cover (50) has a sleeve-shaped body (52) and an annular top surface (54), the top surface being arranged radially inwardly on the end side of the body (52), wherein the body (52) is placed on the outer periphery of the stator yoke (34), wherein the top surface (54) is at least axially overlapped with the stator winding (40) in a segmental manner, and wherein the body (52) has a number of ventilation openings (60).

Description

Technical Field

[0001] This invention relates to electric motor-type drives for motor vehicles, particularly fan drives, which include an electric motor with a rotor capable of rotating relative to a stationary stator in a manner rotatable about a rotational axis. The invention also relates to an electric motor for such a drive and a cooler fan for a motor vehicle incorporating such a drive. Background Technology

[0002] Motor vehicles with internal combustion engines generate significant heat during operation. To maintain operating temperature, coolant is typically used in air conditioning systems, and this coolant must be cooled. Cooling is usually achieved by passing cool air over cooling ribs that are in thermal equilibrium with the coolant. Because oncoming airflow is often insufficient for cooling, especially at low speeds, a cooler frame with an electric (motor-type) drive can be fastened to the cooler, which includes the cooling ribs. The electric drive generates additional airflow, which is guided by the frame. For this purpose, the (fan) drive has an electric motor, which is technically coupled to the drive components, particularly to the fan impeller that generates the airflow.

[0003] Typically, the frame has a generally circular void within which the fan drive is arranged. The plane of the fan impeller is generally parallel to the plane of the cooling ribs. An electric motor, driven by the fan impeller, is fixed to a rigid retainer on the end side by screws or rivets, wherein the retainer is held at the center of the void by radially oriented struts.

[0004] For example, brushless electric motors are used for this purpose, in which a rotor, supported in a manner rotatable relative to the stator, is driven by a rotating magnetic field. During the operation of the electric motor, alternating currents are generated in the circuitry of the motor electronics and in the rotating field windings due to the switching process. These alternating currents generate corresponding interfering electromagnetic fields, which are considered critical in terms of compliance with EMV (electromagnetic compatibility) guidelines.

[0005] DE 10 2017 210 734 A1 discloses an electric motor-type driver with a cover for influencing and / or shielding interfering electromagnetic fields generated during electric motor operation. The cover is, for example, designed as a sleeve-shaped body that rests on the outer periphery of the stator. Here, the sleeve has a plurality of radially inwardly curved tongues that at least partially cover the coils of the stator windings.

[0006] DE 11 2017 001 793 T5 describes an electric motor-type drive device with an annular cover axially mounted on a stator at one end. The cover has several circumferentially distributed openings to improve cooling capacity. The cover is open at one end for cooling the motor's internal space or for ventilation within the motor.

[0007] DE 10 2015 217 702 A1 describes an electric motor drive with a columnar cover, the cover having several circumferentially distributed openings on its end side, each opening positioned between two adjacent stator teeth. The end-side openings are hereby used solely for cooling the internal space of the motor or for internal ventilation. Summary of the Invention

[0008] The object of this invention is to provide a particularly suitable electric motor-type drive for motor vehicles. In particular, the drive is improved in terms of the radiation of interfering electromagnetic fields during electric motor operation. Another object of this invention is to provide an electric motor suitable for this drive, and a cooler fan for motor vehicles equipped with such a drive.

[0009] In terms of drives, the objective of the invention is solved by the features of the invention; in terms of electric motors, the objective of the invention is solved by the features of the invention; and in terms of cooler fans, the objective of the invention is solved by the features of the invention.

[0010] The electric motor-type drive according to the invention is configured and adapted for use in motor vehicles. The drive is specifically constructed as a fan drive. The drive has an electric motor with a rotor supported in a rotatable manner and a stationary or fixed stator.

[0011] The stator has a lamination group (stator lamination group), which forms a stator yoke and stator teeth radially extending from the stator yoke, wherein stator windings are carried on the stator teeth. The stator windings are formed, for example, by a plurality of interconnected stator coils, which are mounted on the stator teeth.

[0012] The actuator also has a conductive cover for influencing and / or shielding interfering electromagnetic fields generated during electric motor operation. The cover is suitably coupled conductively to a zero potential, such as a motor mount supporting the electric motor. Interfering electromagnetic fields generated during operation are blocked and / or damped and / or deflected and / or attenuated by the cover according to the invention, thereby improving the actuator's electromagnetic compatibility (EMV). The conjunction "and / or" here and hereinafter should be understood to mean that features connected by this conjunction can be designed together or as alternatives to each other.

[0013] The cover has a sleeve-shaped body and an annular top surface, wherein the top surface extends radially inwardly onto the end side of the sleeve. In the installed state, the sleeve rests on the outer periphery of the stator yoke, wherein the top surface at least segmentally overlaps the stator winding. According to the invention, the sleeve is provided with a plurality of ventilation openings distributed circumferentially. Thus, on the one hand, reliable end-side shielding and / or attenuation of interfering electromagnetic fields in the axial direction is achieved through the top surface; on the other hand, reliable air circulation and thus (air) cooling of the stator winding is achieved through the ventilation openings on the circumferential side of the sleeve, so that the cover has as little or no effect on motor cooling or stator cooling as possible. This results in a particularly suitable electric motor type drive.

[0014] The cover preferably has a high shielding potential, thus complying with EMV specifications. Furthermore, the cover achieves cost-effective and stable mechanical reduction of interfering electromagnetic fields. The cover is easy to install and has a simple component geometry. In particular, the cover is implemented separately from the stator, allowing for optional use of the cover.

[0015] In the installed state, the cover is statically held on the stator, so that the cover has virtually no impact on the balance quality of the electric motor. Here, the cover is preferably fastened or held to the stator yoke by a sleeve, which advantageously utilizes existing fastening possibilities within the drive unit or electric motor. Therefore, the cover has virtually no impact on existing installation space.

[0016] "Axial" or "axial direction" here and below is specifically understood as a direction parallel to (coaxial with) the axis of rotation of the electric motor, i.e., a direction perpendicular to the end side of the stator. Correspondingly, "radial" or "radial direction" here and below is specifically understood as a direction oriented along the radius of the stator or electric motor and perpendicular to (transverse to) the axis of rotation of the electric motor. "Circumferential direction" here and below is specifically understood as a direction along the circumference of the stator or electric motor (tangential direction, azimuth direction), i.e., a direction perpendicular to both the axial and radial directions.

[0017] In a suitable design, ventilation openings are located circumferentially within the respective stator tooth region. In other words, the sleeve has at least a number of ventilation openings equal to the number of stator teeth. These ventilation openings specifically extend into the terminal region, ensuring reliable cooling of the stator teeth and thus, the stator windings. In a preferred design, each stator tooth has two ventilation openings.

[0018] Alternatively, one could consider having fewer ventilation openings than stator teeth. In such designs, for example, large ventilation openings extend on each of two stator teeth.

[0019] The top surface is, for example, a continuous circular ring, so that the stator windings (including the terminals) are substantially completely covered. However, in an advantageous improvement, the top surface has several openings arranged circumferentially. In other words, the top surface on the end sides is partially open circumferentially.

[0020] In a suitable design, the opening is arranged circumferentially between two adjacent stator teeth. Thus, the opening is introduced only in areas where no coil windings or stator windings are located. This ensures reliable shielding against interfering electromagnetic fields. Specifically, ventilation openings for radial cooling and end-side or axial openings on the top surface are alternately provided along the circumferential direction.

[0021] In one possible implementation, the stator has a terminal mounted on the stator lamination assembly as a wire guide. The terminal is implemented here as a segmented annular wall protruding axially from the stator lamination assembly. Here, the segmented wall forms an upright wire-holding nose for guiding the winding wire of the stator winding. The terminal is, for example, a part of the injection-molded stator lamination assembly, or a part of a wiring unit (connector ring, contact device) mounted on the stator lamination assembly. Due to the terminal, during winding, the winding wire of the stator winding can be guided circumferentially behind the stator teeth one by one, preventing the winding wire from colliding with the winding tool.

[0022] In an advantageous design, the opening on the top surface is positioned within the area of ​​the terminal or segmented wall. Thus, the terminal is inserted into the opening on the top surface. In other words, the top surface is penetrated by the terminal within the area of ​​the opening. This prevents the cover from twisting relative to the stator and creates a positioning aid during the installation of the cover. Furthermore, the electric motor thus maintains the same structural height whether or not it has a cover.

[0023] The opening on the top surface serves only to meet axial structural space requirements and does not have a cooling function, because the embedded elements of the terminals or stator enclosure essentially fulfill the cooling function. In other words, the opening on the top surface is not used as a cooling opening for temperature regulation or cooling of the motor's internal space. The opening is therefore essentially closed by the inserted terminals or wire guides.

[0024] Therefore, the opening on the top surface differs from DE 10 2015 217 702 A1 and DE 11 2017 001 793T5 in that the opening contributes little or no to ventilation or cooling of the motor's internal space. Compared to the prior art, the opening on the top surface according to the invention serves only to reduce the axial structural space requirement of the cover, and is positioned as close as possible to the wire guide of the terminal. Although certain gap regions exist between the inserted terminal and the surrounding opening due to tolerances and clearances, the size of these gap regions is kept as small as possible, thus contributing little to ventilation and / or cooling of the motor's internal space.

[0025] In a structurally particularly stable design, the top surface is integrally formed onto the sleeve, either as a single piece or a single unit. In other words, the top surface and the sleeve form a common component. This enables exceptionally simple installation.

[0026] Additional or additional aspects of the invention provide an electric motor for the aforementioned drive. Here, the description relating to the drive also applies in a meaningful sense to the electric motor, and vice versa.

[0027] Electric motors are appropriately designed as internal actuators.

[0028] The cooler fan according to the invention is configured and adapted for and set up for use in motor vehicles. The cooler fan has a drive of the aforementioned electric motor type and a fan impeller driven thereby. The advantages and design schemes listed regarding the drive and / or electric motor can also be applied to the cooler fan, and vice versa. Attached Figure Description

[0029] The embodiments of the present invention are explained in detail below with reference to the accompanying drawings. Wherein:

[0030] Figure 1 The cooler fan with an electric motor drive is shown in the exploded perspective view;

[0031] Figure 2 The driver with the cover is shown in the perspective view, and

[0032] Figure 3 The cover is shown in the perspective view.

[0033] In all the accompanying drawings, the corresponding parts and dimensions are always labeled with the same reference numerals. Detailed Implementation

[0034] Figure 1An exploded view of a cooler fan 2 is shown, specifically designed for use in motor vehicles not shown further herein. The cooler fan 2 has an electric motor drive 4 and a fan impeller 6 coupled thereto.

[0035] The driver 4 has an electric motor 8, which is coupled to a fan impeller 6 at one end and to a motor bracket 10 at the end opposite to the fan impeller 6. The motor bracket 10 has three flanges 12 for securing the cooler fan 2. Furthermore, the motor bracket 10 has an electronics housing 14 for motor electronics 16 on its side opposite to the electric motor 8, which is covered by an electronics housing cover 18 in the installed state.

[0036] The electric motor 8 includes a rotor 20 and a stator 22. The rotor 20 is supported in such a way that it can rotate or rotate about a rotation axis D by means of a pivot pin 24, wherein the rotation axis D is oriented along the axial direction A of the electric motor 8.

[0037] The rotor 20 is rotatably supported on the pin 24 by bearings 26. In the illustrated embodiment, the electric motor 8 is configured as an inner mover, meaning that the stator 22 coaxially surrounds the rotor 20 on the outside with respect to the radial direction R perpendicular to the axial direction A. However, in a variant of the drive 4 according to the invention, not further shown, the electric motor 8 is configured as an outer mover. The embodiments described below apply in a similar manner.

[0038] The rotor 20 is in drive connection with the fan impeller 6. On the outer periphery of the fan impeller 6, the fan impeller 6 has air guide vanes 28; for better overview, only a portion of these air guide vanes is shown. The fan impeller 6 has a central cover 30 fastened to the rotor 20 of the electric motor 8.

[0039] The stator 22 is basically composed of annular, especially stamped, stacked (stator) laminations 32. Figure 2 The lamination assembly 32 has a stator yoke 34 that is substantially hollow and cylindrical. A plurality of stator teeth 36 extend from the stator yoke, the stator teeth being arranged in a star shape and pointing radially inward toward the rotor 20. In the illustrated embodiment, for example, twelve stator teeth 36 are provided.

[0040] Stator slots (not shown in detail) are formed between adjacent stator teeth 36, and the coils 38 of the stator windings 40 are housed within these slots. In other words, the stator teeth 36 are provided with multi-phase rotating field windings as the stator windings 40, wherein each phase includes at least one coil or coil winding 38 having first and second coil ends. Here, the coils 38 are specifically arranged as single coils on each stator tooth 36. Alternatively, double or multiple coils are also conceivable, with the coil windings 40 mounted on two or more stator teeth 36.

[0041] Accordingly, motor electronics 16 energizes the stator winding 40 via phase terminals 42 to generate a rotating field. Motor electronics 16 is connected to a power source, such as an onboard electrical grid, via a connecting cable 44.

[0042] To enable the coil ends to be laid, contacted, and wired to the rotating field winding 40, an injection-molded encapsulation 46 is provided, for example. Alternatively, the stator 22 may have an annular contact device (wiring unit) in the form of a laying ring or wiring ring placed on the end side of the lamination assembly 32.

[0043] By injection molding 46, the stator teeth 36 are essentially surrounded by an insulated coil body or winding body. The coil body, for example, has a slotted recess for guiding the winding wire and flanged sidewalls for preventing the manufactured coil 38 from loosening (radially) from the stator teeth 36.

[0044] The injection-molded encapsulation 46 has a shaped terminal 48, which protrudes axially from the lamination assembly 32 as a segmented annular wall. Due to the terminal 48, the winding wire can be guided circumferentially behind the stator teeth 36 one by one during the winding process, so that the winding wire does not collide with the winding tool.

[0045] Figure 2 The driver 4 is shown at an angle toward the end side of the fan impeller 6. A cover 50 is mounted on the end side of the electric motor 8. The cover 50 is made of a conductive material and is conductively guided, for example, to the motor bracket 10, which is at zero potential. The cover 50 blocks and / or dampes and / or deflects and / or reduces the interfering electromagnetic field generated during operation of the stator winding 40, thereby improving the electromagnetic compatibility (EMV) of the driver 4.

[0046] exist Figure 3 The cover 50 shown separately has a sleeve 52 (sleeve sleeve, stator sleeve), which is placed on the outer periphery of the stator 22 or stator yoke 34 in the installation state.

[0047] The cover 50 also has a top surface 54, particularly integrally formed onto the end side of the sleeve 52. The generally annular top surface 54 is formed radially inwardly extending from the end side of the sleeve 52 facing the fan impeller 6. In other words, the top surface 54 is radially curved inwardly from the sleeve 52. As particularly in… Figure 2 As can be seen, the top surface 54 overlaps or covers the coil 38 of the stator winding 40. This means that the stator winding 40 is axially covered by the top surface 54 in the direction of the fan impeller 6.

[0048] In this embodiment, twenty-four circumferentially distributed ribs 56 are introduced on the inner surface of the sleeve 52 opposite to the stator 22, with two ribs 56 for each stator tooth 36. The ribs extend radially into the opening of the sleeve 52 on the inner surface of the sleeve facing the stator 22. The ribs 56 are used to compensate for radial clearance or for tolerance compensation between the cover 50 and the outer periphery of the stator 22 or the stator yoke 34.

[0049] Between the ribs 56 of the stator teeth 36, rib-shaped contact elements 58 are formed within the sleeve 52. In the installed state, the contact elements 58 can make conductive physical contact with the lamination group 32.

[0050] Between the ribs 56, specifically within the respective stator teeth 36, two window-shaped ventilation openings 60 are introduced. This means that the ventilation openings 60 are distributed along the circumferential direction U on the sleeve 52. Reliable air circulation is achieved through the ventilation openings 60 on the circumferential side of the sleeve 52, and thus (air) cooling of the stator windings 40 is achieved, so that the cover 60 has the lowest possible or virtually no impact on motor cooling or stator cooling.

[0051] Within the stator slots between the stator teeth 36, locking tab-shaped fixing elements 62 are introduced into the sleeve 52. The fixing elements 62 are used to axially fix or fasten the cover 50 to the stator 22. For this purpose, the fixing elements 62, in the installed state, are at least partially embedded in the rear edge of the lamination assembly 32 or the injection-molded encapsulation 46 radially protruding. Thus, the cover 50 is statically held on the stator 22, so that the cover has virtually no impact on the balance quality of the electric motor 8.

[0052] The sleeve 52 of the cover 50 is formed, for example, from a rolled or bent strip of metal sheet, wherein the opposing ends of the sheet sheet are joined together at a joint to form an annular sleeve 52. Alternatively, the cover 50 or sleeve 52 is implemented as a deep-drawn component.

[0053] The top surface has several window-like openings 64 arranged in a circumferential direction U. In other words, the top surface is partially open in the circumferential direction U. Here, the openings 64 are arranged in the circumferential direction U between two adjacent stator teeth 36, that is, in the region of the stator slot. The openings 64 are therefore arranged in the region of the terminal 48. Thus, the terminal 48 is inserted into the opening of the top surface 64. Therefore, the terminal 48 serves to prevent the cover 50 from twisting relative to the stator 22 on the one hand, and forms a positioning aid when the cover 50 is installed on the other hand. Furthermore, the electric motor 8 thus has the same axial structural height with and without the cover 50. With the inserted terminal 48, the openings 64 do not contribute to the ventilation or cooling of the internal space of the motor.

[0054] This invention is not limited to the embodiments described above. Rather, those skilled in the art can derive other variations of the invention from this description without departing from its subject matter. In particular, all the individual features described in connection with the embodiments can be combined with each other in other ways without departing from the subject matter of the invention.

[0055] List of icon numbers

[0056] 2 Cooler fan 38 coils

[0057] 4 Drivers 40 Stator Windings

[0058] 6 fan impellers with 42 phase terminals

[0059] 8 Electric motor 44 Connecting cable

[0060] 10 Motor bracket 46 Injection molded encapsulation

[0061] 12 flange pieces 48 terminals

[0062] 14 Electronic component box 50 Cover piece

[0063] 16 sets of motor electronic components

[0064] 18 Electronic component box cover 54 Top surface

[0065] 20 Rotor 56 Ribs

[0066] 22 Stator 58 Contact Elements

[0067] 24 shaft pins, 60 ventilation openings

[0068] 26 Bearings 62 Fixing Components

[0069] 28 air guide vanes, 64 openings

[0070] 30 masks

[0071] 32. Stacked assembly A, axial direction

[0072] 34 Stator yoke R Radial direction

[0073] 36 Stator teeth U circumferential direction

Claims

1. An electric motor type drive (4) for a motor vehicle, said drive having: - An electric motor (8) having a rotor (20) supported in a rotatable manner and a stator (22) having laminations (32) forming a stator yoke (34) and stator teeth (36) radially extending from the stator yoke, wherein, The stator winding (40) is carried on the stator teeth (36), and - A conductive cover (50) for influencing and / or shielding interfering electromagnetic fields generated during electric motor operation. -The cover (50) has a sleeve-shaped body (52) and a top surface (54), the top surface being a continuous ring, and the top surface (54) extending radially inwardly onto the end side of the body (52). -The sleeve (52) is placed on the outer periphery of the stator yoke (34). - wherein the top surface (54) at least axially overlaps the stator winding (40) in sections, and -The sleeve (52) has several ventilation openings (60), The top surface (54) has a plurality of openings (64) arranged in a manner distributed along the circumferential direction (U). The stator (22) has a terminal (48) mounted on the lamination assembly (32), the terminal (48) protruding axially from the lamination assembly (32) as a segmented annular wall. The opening (64) is arranged within the area of ​​the terminal (48). The terminal (48) is inserted into the opening (64) on the top surface (54). The opening (64) is window-shaped. The window-shaped opening (64) is closed / filled by the interlocking terminals. The top surface (54) is integrally formed onto the sleeve (52), and the cover (50) is a deep-drawn component.

2. The driver (4) according to claim 1, Its features are, At least one ventilation opening (60) of the sleeve (52) is provided in the area of ​​the stator tooth (36).

3. The driver (4) according to claim 1, Its features are, The opening (64) is arranged in the circumferential direction (U) between two adjacent stator teeth (36).

4. The driver (4) according to claim 1, Its features are, The driver is a fan driver.

5. An electric motor (8) used in a drive (4) according to any one of claims 1 to 4.

6. The electric motor (8) according to claim 5, wherein, The electric motor (8) is implemented as an internal actuator.

7. A cooler fan (2) for a motor vehicle, the cooler fan having a driver (4) according to any one of claims 1 to 4 and having a fan impeller (6).

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