阅读说明：本技术 用于使旋转体动平衡的方法 (Method for dynamically balancing a rotating body ) 是由 罗兰德·卡尔巴 赫尔穆特·普法尔茨格拉夫 于 2020-05-27 设计创作，主要内容包括：本发明涉及用于使旋转体(4)动平衡的方法,其中,使旋转体(4)处于旋转中,其中,确定旋转体(4)的不平衡,其中,依赖于所确定的不平衡将旋转体(4)的材料去除和/或将附加材料(22)添补到旋转体(4)上,并且其中,借助激光器(8)的激光束(10)来执行去除和/或添补。(The invention relates to a method for dynamically balancing a rotating body (4), wherein the rotating body (4) is set in rotation, wherein an imbalance of the rotating body (4) is determined, wherein material of the rotating body (4) is removed and/or additional material (22) is added to the rotating body (4) as a function of the determined imbalance, and wherein the removal and/or addition is carried out by means of a laser beam (10) of a laser (8).)

1. Method for dynamically balancing a rotating body (4),

-wherein the rotating body (4) is put in rotation,

-wherein an unbalance of the rotating body (4) is determined,

-wherein material of the rotating body (4) is removed and/or additional material (22) is added to the rotating body (4) depending on the determined unbalance,

and is

-wherein the removal and/or the replenishment is performed by means of a laser beam (10) of a laser (8).

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

removal and/or replenishment is performed during rotation of the rotating body (4).

3. The method according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

-linearly applying said additional material (22).

4. The method of any one of claims 1 to 3,

it is characterized in that the preparation method is characterized in that,

during the removal and/or replenishment, the laser beam (10) is moved on the outer circumference (42) of the rotating body (4) by means of a deflection element (24).

5. The method of any one of claims 1 to 4,

it is characterized in that the preparation method is characterized in that,

a balancing mass (44) is fastened to the outer circumference (42) of the rotary body (4), on which balancing mass removal and/or replenishment takes place.

6. The method of claim 5, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the balancing mass (44) is fastened to the outer circumference (42) by welding in a material-locking manner.

7. The method according to claim 4 or 5,

it is characterized in that the preparation method is characterized in that,

-fastening a balancing mass (44) having an inner radius smaller than the outer radius of the periphery (42).

8. Device (2) for dynamically balancing a rotating body (5), having an unbalance measuring device (6) for determining an unbalance of the rotating body (4) and a laser (8) for generating a laser beam (10) by means of which material of the rotating body (4) can be removed and/or additional material (22) can be added to the rotating body (4), and having a controller (12) for carrying out the method according to any one of claims 1 to 7.

9. Electric motor of a motor vehicle having a rotating body (4) that is dynamically balanced with a method according to any one of claims 1 to 7.

10. Use of the method according to any one of claims 1 to 7 for dynamically balancing a motor housing (26) having a magnet element (28) embedded therein.

Technical Field

The invention relates to a method for dynamically balancing a rotor, in particular a motor housing of an electric motor. The invention also relates to a device for dynamically balancing a rotor and to an electric motor having a rotor balanced in the method, and to the use of the method for dynamically balancing a motor housing having a magnet element inserted therein.

Background

A rotating or rotationally symmetrical component as a rotating body always has at least a certain degree of imbalance due to tolerances resulting from manufacturing or construction. An imbalance is to be understood here to mean, in particular, an asymmetrical mass distribution of the (rotationally symmetrical) rotating body, as a result of which its axis of rotation does not coincide or coincide with its principal axis of inertia. During the rotation of the rotary body, unbalanced forces occur as centrifugal or centripetal forces due to the imbalance, which increase with increasing rotational speed and lead to a non-circular, oval-shaped rotational movement of the rotary body. As a result, undesirable vibrations and noise are generated during operation due to the imbalance of the rotating body.

The service life of a product having a component or a rotary body and/or the service life of a bearing rotatably supporting the rotary body may be reduced due to the unbalance. Furthermore, there is a risk of damage or complete destruction of components and/or bearings, in particular at high rotational speeds.

In particular in the case of electric motors of motor vehicles, which are arranged, for example, in the region of the cabin, an operation which reduces noise as far as possible is desirable. Furthermore, an electric motor of this type should be as compact as possible, i.e. have as few as possible (built-in) overall dimensions. Electric motors of this type therefore require rotationally symmetrical components, such as a rotor or a motor housing, which have as few imbalances as possible.

To eliminate or correct the imbalance it is possible to: balancing the rotating body or member. The asymmetrical mass distribution of the rotating body is corrected or compensated for during balancing. This is achieved, for example, by moving the additional mass into place or into place, or by removing or eliminating the mass of the rotating body, for example by means of a cutting process. As a result, mechanical forces act on the rotating body during the course of the balancing process.

In the case of (mass) balancing, there is a difference between dynamic and static balancing. In static balancing, only the static share of the imbalance is compensated, the balancing taking place in a plane. In dynamic balancing, a static imbalance fraction and a dynamic (instantaneous) imbalance fraction are compensated. In this case, the radial and axial position of the imbalance on the rotating body is observed and compensated. The balancing thus takes place in two planes of the rotary body. Thus, the oval, non-circular rotational movement is prevented or at least significantly reduced by the dynamic balancing.

In particular, problems arise with conventional balancing methods in the case of high demands with regard to low noise and service life of the electric motor, which is compact in terms of installation space. In general, the unbalance of the rotating body or component is determined before and after the unbalance by means of an unbalance measuring device and, depending on this, material or mass is added to or removed from the rotating body. Balancing and measurement of unbalance are usually carried out in separate devices, whereby a uniform production flow is made difficult when manufacturing electric motors or components.

Disclosure of Invention

The object of the invention is to provide a particularly suitable method for dynamically balancing a rotor. The object of the invention is also to specify a particularly suitable device for carrying out the method. The object of the invention is to specify a particularly suitable electric motor having a rotor balanced in this way and a particularly suitable application for dynamically balancing a motor housing having a magnet element inserted therein.

On the one hand, this object is achieved by the features of claim 1, on the other hand, on the one hand, and on the other hand, on the one hand, by the features of claim 8, on the one hand, and on the other hand, on the one hand, by the features of claim 9, on the one hand, and on the other hand, on the one hand, and on the other hand, by the features of claim 10, on the one hand, and on the device hand, and on the one hand, and on the other hand, by the features of claim 8, and on the electric motor, and on the other hand. Advantageous embodiments and improvements are the subject matter of the respective dependent claims. The advantages and embodiments provided in relation to the method can also be transferred meaningfully to the device and/or the electric motor and/or the application and vice versa.

The method according to the invention is suitable and designed for dynamically balancing a rotating body, i.e. a rotationally symmetrical component or workpiece. The rotary body is, for example, a component of an electric motor, in particular a rotor or a motor housing.

According to the method, the rotating body is set in rotation and its imbalance is then determined. Depending on the determined imbalance, material of the rotating body is removed and/or additional material is added to the rotating body. As a result, an imbalance compensation or imbalance correction is carried out as a function of the detected or determined imbalance in order to reduce the imbalance, i.e. to reduce the asymmetrical mass distribution of the rotating body. The conjunction "and/or" is understood here and in the following to be able to be constructed jointly and as an alternative to one another by means of the features associated with the conjunction.

Unbalance compensation or unbalance correction, i.e. the removal of material from the rotating body and/or the addition of material to the rotating body, is carried out here by means of the laser beam of a laser. A particularly suitable method for balancing the rotating body is thereby achieved.

A particularly precise or precise balancing of the rotating body can be achieved by means of a laser or a laser beam. This also enables small imbalances to be reliably eliminated. A particularly high balancing quality of the rotating body can thus be achieved by means of the laser. In addition, no additional mechanical forces act on the rotary body in the case of such laser balancing.

The removal is therefore carried out in particular by means of (subtractive, negative) laser removal, the replenishment being carried out in particular by means of (additive, positive) laser replenishment or Laser Melt Deposition (LMD). During the application, the additional material is fed in the form of a strand or metal powder and applied to the rotating body layer by layer, and is joined or fused together in a cohesive manner (stoffschlussig) with the material of the rotating body by means of a laser beam in a pore-free and crack-free manner.

The method according to the invention is in particular provided for fine balancing of a rotating body, i.e. for correcting or compensating for a relatively small imbalance or a relatively small asymmetrical mass distribution. In this case, it is possible in the case of a large imbalance to: a two-stage balancing method is provided, in which the imbalance is reduced in a rough method step, for example by means of a machining process, and in which the method according to the invention is used in a second, subsequent, finer method step.

In an advantageous embodiment, the removal and/or replenishment is carried out during rotation of the rotary body. In particular, the removal and/or the replenishment is carried out here, for example, during the determination of the imbalance. Thus, the rotor is dynamically balanced substantially simultaneously with measuring or determining the imbalance. This means that: for example, measuring the rotating body and balancing the rotating body simultaneously. This enables an integrated control process.

In a possible embodiment, the removal takes place in particular when the rotary body rotates at the nominal rotational speed. Due to the relatively rapid rotation of the rotary body during removal, particularly low energy or heat input acts on the component or the rotary body, so that substantially no twisting of the rotary body occurs during removal.

In particular, the replenishing is carried out when the rotary body rotates at the following rotational speed: during the replenishment period, the rotational speed is significantly lower than the nominal rotational speed. The rotational speed during the removal is, for example, between more than 0% (stationary state) and 10% of the nominal rotational speed, in particular between more than 0% and 5% of the nominal rotational speed, preferably between more than 0% and 2% of the nominal rotational speed. Therefore, the replenishment or the positive balancing is not carried out in the stationary state of the rotary body, but rather in the case of a slow rotation which is reduced compared to the nominal rotational speed.

Therefore, unbalance compensation or unbalance correction is performed during rotation of the rotating body. The balancing is thus performed "on the fly", thereby making particularly uniform production and manufacture of the rotary body possible.

In a preferred embodiment of the method, the additional material is applied in the form of a wire or strip. This achieves a particularly effective and targeted replenishment of the additional material with respect to the heat input rotor.

In a suitable development, the laser beam is moved on the outer circumference of the rotational body by means of a deflection element during removal and/or during replenishment. The deflection element is suitably designed as a laser deflector or as a mirror. The efficiency of the method is thereby significantly improved, since the laser beam is not only arranged at the location of the rotating body, but can be moved substantially over its entire circumference, in particular while the rotating body is rotating. This means that: the laser beam is moved by means of the deflection element, in particular in the axial direction of the rotating body, wherein the laser beam is moved in the tangential or circumferential direction thereof as a result of the rotation of the rotating body.

In an alternative refinement, it is conceivable, for example, to move the laser beam or the laser itself over the outer circumference of the rotating body by means of a scanner.

Additional or further aspects of the invention provide for: the balancing mass is fastened to the outer circumference of the rotating body, wherein the balancing mass is removed and/or supplemented only by means of the laser beam. Thereby, the energy and heat input to the rotating body itself are reduced. Such a separate balancing mass is advantageous in particular in those rotating bodies which have an adverse effect on the heating of the rotating body material in the region of the laser beam.

For the purpose of secure and permanent fastening, the balancing mass is joined to the outer circumference of the rotary body in a material-locking manner, in particular by welding. This ensures that the balancing masses are secured in an operationally safe manner even at high rotational speeds of the rotary body.

"cohesive" or "cohesive connection" between at least two interconnected parts is understood here and in the following in particular to mean that the interconnected parts are held together at their contact surfaces by material bonds or cross-links (for example atom-based or molecular bonds) optionally under the action of additional materials.

In a preferred embodiment, in particular, the balancing mass is fastened, the inner radius of which is determined to be smaller than the outer radius of the outer circumference. This means that: the balancing mass has a substantially arcuate cross-sectional shape, wherein the balancing mass rests against the outer circumference of the rotary body only in the region of the free ends of the bow arms. In the region of the apex of the balancing mass, a free space is thus formed between the rotating body and the balancing mass, i.e. a clear distance is formed. This free space or gap serves as a thermal insulation between the balancing mass and the rotary body. In this way, a thermal decoupling of the balancing mass from the rotating body is achieved, whereby the energy and heat input into the rotating body during the removal and/or replenishment process is further reduced.

The device according to the invention is suitable and designed for dynamically balancing a rotor. The device has an imbalance measuring device for determining an imbalance of the rotating body. The device also has a laser for generating a laser beam, by means of which material of the rotating body can be removed and/or additional material can be added to the rotating body. The unbalance measuring device and the laser are coupled to a controller, i.e. a control unit.

The controller is generally configured in programming and/or circuitry for carrying out the method according to the invention described above. The controller is therefore particularly set up to determine the imbalance of the rotating body, i.e. the position and location of the asymmetrical mass distribution, from the imbalance data of the imbalance measuring device and to calculate the required imbalance compensation or imbalance correction and to reduce the imbalance by actuating the laser.

In a preferred embodiment, the controller is formed at least in the core by a microcontroller with a processor and a data memory, wherein the functions for carrying out the method according to the invention are implemented in the form of operating software (firmware) on the programming technology, so that the method is automatically executed in the microcontroller (optionally interactively with the user of the device) when the operating software is executed. The controller can also be formed within the scope of the invention alternatively by electronic components that cannot be programmed, for example an application-specific integrated circuit (ASIC), wherein the functions for carrying out the method according to the invention are carried out using circuit-technology components.

In this case, the unbalance measuring device has, for example, a receptacle for a rotary body and rotates it during operation, wherein the occurring unbalance forces are detected by means of a force sensor. The controller determines or calculates the imbalance of the rotating body and the required imbalance compensation from the received force signals. At substantially the same time, the laser beam is incident continuously or in a pulsating manner on, in particular, the rotating body in order to achieve or achieve an imbalance compensation.

The laser is, for example, embodied as a continuously operating fiber laser having a laser power of, for example, 12kW (kilowatts), wherein the wavelength is adapted in particular to the material of the rotating body to be removed and/or to the additional material to be added. For example, in the case of carbon steel, a fiber laser having a wavelength of approximately 1060nm (nanometers) is used in particular.

In this case, the laser beam is incident on the rotary body or the additional material in a pulsating manner, in particular in the course of the application or removal. In this case, for example, the pulse length or pulse duration of a single pulse of the laser is set to be less than 100 μ s (microseconds). Several single pulses can be generated one after the other as pulse packets or pulse sequences for removal or replenishment, for example with a pulse packet duration of up to 10ms (milliseconds). The laser is expediently synchronized with the unbalance measuring device.

The electric motor according to the invention is provided for a motor vehicle and has a rotary body which performs dynamic balancing according to the method described previously. The rotary body is, for example, a motor housing, in particular a pole pot, having a magnet element, in particular a motor ring magnet, inserted therein. The electric motor is designed, for example, as an outer rotor of an electric actuating drive (for example, a cooler fan or a window lifter) for a motor vehicle, wherein the motor housing with the motor ring magnet is embodied, in particular, as a rotor of the electric motor.

The magnet element is temperature-sensitive because demagnetization effects occur, for example, above 120 ℃. By means of the method according to the invention, a particularly low heat input to the motor housing and the magnet element is ensured, as a result of which the rotary body performs a dynamic balancing in a simple and reliable manner. This makes particularly uniform production and production of the rotary body and thus of the electric motor possible.

In a preferred application, the method described above is therefore used in particular for dynamically balancing the mass of a motor housing having a magnet element inserted therein.

Drawings

Next, embodiments of the present invention are explained in detail based on the drawings. The figures are shown in a schematic and simplified manner, in which:

fig. 1 shows, in a partial sectional view, an apparatus for dynamically balancing a motor housing as a rotary body;

fig. 2 shows a motor housing with a shaft in a perspective view;

fig. 3 shows a perspective view of a motor housing with a balancing mass; and

fig. 4 shows the motor housing with the balancing mass in a partial section along the line IV-IV in fig. 3.

Parts and parameters corresponding to each other are provided with the same reference numerals throughout the figures.

Detailed Description

Fig. 1 schematically and simply shows a device 2 for dynamically balancing a rotating body 4. The device 2 has an unbalance measuring device 6 for determining an unbalance of the rotating body 4. The device 2 also has a laser 8 for generating a laser beam 10, by means of which material of the rotating body 4 is removed and/or additional material is added to the rotating body 4 depending on the determined imbalance. The imbalance measuring device 6 and the laser 8 are coupled to a controller 12, i.e., a control unit, in terms of signal technology.

The rotary body 4 is preferably mounted on both sides at its end faces along its longitudinal axis in a rotatable manner in bearings 14 of the unbalance measuring device 6, wherein only one bearing 14 is shown by way of example in fig. 1.

The unbalance measuring device 6 has at least one unbalance sensor 16, which detects an occurring unbalance of the rotating body 4, for example by force and/or displacement measurement. Two imbalance sensors 16 are shown in fig. 1 by way of example.

The at least one imbalance sensor 16 transmits the received data as an imbalance signal 18 to the controller 12, which then determines or calculates the imbalance of the rotating rotor 4 and the required imbalance compensation or the required imbalance correction. In this case, the controller 12 determines, in particular, the position and location (Lage) of the asymmetrical mass distribution. The laser 8 or the laser beam 10 is then continuously or pulsed onto the rotating rotor 4 by means of the laser signal 20 in order to achieve or achieve the imbalance compensation. Depending on the unbalance compensation required, either material of the rotary body 4 is removed or removed by subtractive laser removal or additional material 22 is added or added by laser addition or Laser Melt Deposition (LMD) in order to reduce the asymmetrical mass distribution of the rotary body 4.

In the case of removal and/or in the case of replenishment, the laser beam 10 is moved over the outer circumference of the rotating body 4 by means of a deflection element 24 coupled to the controller 12. The deflection element 24 is expediently designed as a laser deflector or mirror. By means of the deflection element 24, the laser beam 10 can be moved in the axial direction of the rotating body 4, wherein the laser beam 10 is simultaneously moved in the tangential or circumferential direction of the rotating body as a result of the rotation of the rotating body 4. This means that: the application and/or removal takes place in particular in the radial and/or axial direction of the rotary body 4.

"axial" or "axial direction" is understood here and in the following especially to be a direction parallel (coaxial) to the axis of rotation D of the rotary body 4. Accordingly, "radial" or "radial direction" is understood here and in the following in particular to mean a direction which is oriented perpendicularly (transversely) to the axis of rotation D of the rotor 4. Here and in the following, a "tangential" or "tangential direction" is understood in particular to mean a direction along the circumference of the rotating body 4 (circumferential direction, azimuthal direction), i.e. a direction perpendicular to the axial direction and perpendicular to the radial direction.

The laser 8 is embodied, for example, as a continuously operating fiber laser with a laser power of 12kW and a wavelength of approximately 1060 nm. In this case, the laser beam 10 is incident on the rotating body 4 in a pulsating manner, in particular in a pulsating manner, during the filling or removal process. The pulse length or pulse duration is set to, for example, 0.1 to 10ms (milliseconds). The laser beam 10 is applied and/or removed in particular linearly along the circumferential or tangential direction of the rotor 4. In this case, the laser 8 is synchronized in particular with the rotation of the rotating body 4 controlled by the unbalance measuring device 6.

Thus, the removal and/or replenishment is performed by means of the device 2 during the rotation of the rotating body 4. In this case, the removal and/or the replenishment is carried out in particular during the determination of the imbalance. Thus, for example, the dynamic balancing of the rotating body 4 is carried out simultaneously with the measurement or determination of the imbalance. Therefore, the unbalance compensation or unbalance correction is performed "on the fly".

In the exemplary embodiment shown in fig. 1 to 4, the rotary body 4 is in particular designed as a rotationally symmetrical component of an electric motor, not shown in detail, of a motor vehicle. The rotary body 4 is embodied in particular as a motor housing 26, in particular as a pole pot, which has a magnet element 28, in particular a (motor) ring magnet, inserted therein and a motor shaft 30. The rotary body 4 is therefore in particular a rotor of an electric motor designed as an outer rotor.

The bell-or pot-shaped motor housing 26 shown in fig. 2 to 4 has a metal stamping in the form of a bearing cap 32 as a housing base and a metal, in particular hollow-cylindrical or tubular, annular wall 34 as a housing circumferential surface or housing wall. The motor shaft 30 has a diameter of, for example, 2 to 10mm (millimeters) and is made of ground steel. The bearing cap 32 and the annular wall 34 as well as the motor shaft 30 are joined to one another by means of a material-locking connection 36. An annular or hollow cylindrical or tubular magnet element 28 is arranged on the inner circumference of the annular wall 34.

In this case, the compensation and/or removal for the unbalance correction preferably takes place in two unbalance or compensation regions 38 and 40 on the outer circumference 42 of the motor housing 26. Substantially annular or band-shaped imbalance regions 38 and 40 are arranged on the annular wall 34 at an axial distance from one another, wherein the imbalance region 38 is arranged on the end of the annular wall 34 facing away from the bearing cover 32 and the imbalance region 40 is arranged on the end of the annular wall 34 facing the bearing cover 32.

The magnet element 28 has, for example, a maximum permissible temperature of approximately 120 ℃. In order to avoid an undesirable exceeding of the magnet temperature, in particular during the radial addition of the additional material 22, it is provided in the exemplary embodiment shown in fig. 3 and 4 that an additional or balancing mass 44 is arranged on the outer circumference 42, to which additional or balancing mass an additional filling is to be made. Thereby reducing the energy and heat input to the annular wall 34 and the magnet element 28.

The balancing masses 44 are expediently arranged in the unbalance regions 38, 40, wherein the balancing masses 44 in the exemplary embodiment of fig. 3 and 4 are arranged in particular in the region 38. In suitable specifications, the balancing mass 44 has, for example, a mass between 5 and 20mg (milligrams) and 100 to 300 mg.

As can be seen in particular in the schematic partial sectional view of fig. 4, the balancing mass 44 is joined to the outer circumference 42 of the motor housing 26, in particular by means of two welding spots 46 in a material-locking manner. The balancing mass 44 has an inner radius, which is dimensioned smaller than the outer radius of the outer periphery 42. The difference in radius between the inner radius of the balancing mass 44 and the outer radius of the outer periphery 42 is, for example, 1mm or less.

Due to the difference in radii, the balancing mass 44 has a substantially arcuate or arched cross-sectional shape, wherein the welding point 46 is arranged in the region of the free end of the limb. Thus, a radial free space 48, i.e. a clear distance in the radial direction, is formed or left between the annular wall 34 and the balancing mass 44 in the region of the apex of the balancing mass 44. This free space 48 serves as a thermal insulation between the balancing mass 44 and the annular wall 34 or the magnet element 28. As a result, a thermal decoupling between the balancing mass 28 and the rotor 4 is achieved, whereby the energy and heat input into the rotor 4 during the removal and/or replenishment process is reduced.

The annular wall 34 and the bearing cover 32 as well as the balancing mass 28 are manufactured, for example, from steel, in particular stainless steel or carbon steel (carbon steel).

The claimed invention is not limited to the embodiments described previously. Rather, other variants of the invention can also be derived from the disclosure by a person skilled in the art within the scope of the claims disclosed, without leaving the subject matter of the invention claimed. In particular, all individual features described in connection with different embodiments can also be combined in other ways within the scope of the disclosed claims without departing from the subject matter of the claimed invention.

List of reference numerals

2 apparatus

4 rotating body

6 unbalance measuring device

8 laser

10 laser beam

12 controller

14 bearing

16 unbalance sensor

18 force signal

20 laser signal

22 additional material

24 deflecting element

26 Motor casing

28 magnet element

30 motor shaft

32 bearing cap

34 annular wall

36 connecting part

38 region of imbalance

40 region of unbalance

42 outer periphery of the outer ring

44 balance mass

46 welding spot

48 free space

Axis of rotation D