Actuator-drive unit

Abstract

Actuator-drive unit (10) comprising an actuator (14) rotatable about an actuator axis (46), and an electric motor (12) driving the actuator (14) with a stator (16) and with a rotor (18), wherein the stator (16) has a stator shaft (34) and is arranged in a fixed position, wherein the rotor (18) is arranged to be rotatable relative to the stator (16) about a rotor axis (38), wherein to drive the rotor (18) and thus the The actuator (14) has coils (40) on the stator (16) and magnets (44) arranged along a circular path (42) on the rotor (18) which interact with the coils (40), wherein the rotor (18) and the actuator (14) are arranged on a common shaft (29) extending along the actuator axis (46), wherein the rotor (18) and the actuator (14) are connected to the shaft (29) in a rotationally fixed manner, such that the rotor (18) and the actuator (14) are rotatably mounted on the shaft (29) in at least one common bearing point (22, 24), characterized in that an actuator frame (20) is provided and that the at least one common bearing point (22, 24) is arranged on the actuator frame (20), that the stator (16) is arranged in a stator housing (36) which can be detachably arranged on the actuator frame (20), and that a sufficiently large air gap is provided between the rotor (18) and the stator (16) such that the stator housing (36) can be arranged on the actuator frame (20) such that the stator axis (34) and the rotor axis (38) have an axis offset (48) to each other.

Description

[0001] The application relates to an actuator-drive unit comprising an actuator rotatable about an actuator axis and an electric motor driving the actuator, the motor comprising a rotor and a stator. The stator has a stator axis and is stationary. The rotor is rotatably arranged relative to the stator about a rotor axis. To drive the rotor and the actuator shaft or the actuator itself, coils are provided on the stator, and magnets are arranged along a circular path on the rotor, interacting with the coils.

[0002] From DE 10 2013 000 420 A1, such an actuator-drive unit is known, wherein a revolving door is provided as the actuator. From DE 100 24 692 A1, a control device for gas flows with a pivotable flap is known. DE 10 2013 224 923 A1 discloses a flap arrangement for an exhaust valve of an internal combustion engine. From US 6,541,881 B1, a DC motor with a rotor and a stator is known, wherein the rotor is rotationally fixed to an actuator, and wherein the stator is arranged between the rotor and the actuator. From DE 88 05 211 U1, a throttle valve and an actuator motor are known.

[0003] Actuator-drive units are also known from the prior art, which essentially consist of two units. One unit comprises an electric motor with a housing, the housing containing a rotor and a stator. The stator is fixedly mounted to the housing. The rotor is rotatably mounted in the housing relative to both the housing and the stator. The stator axis lies on the rotor axis. A rotor shaft, mounted in the housing of the electric motor, is attached to the rotor and projects out of the housing. Another unit comprises the actuator, which is mounted on an actuator shaft. The actuator shaft is mounted on an actuator frame. A detachable coupling, in particular a jaw coupling, is provided between the rotor shaft and the actuator shaft to connect the electric motor to the actuator.Alternatively, the coupling can be located inside the housing of the electric motor. The coupling is required to compensate for any axial misalignment between the rotor shaft and the actuator shaft if the mounting is not perfectly aligned. The coupling can also provide overload protection for the motor.

[0004] The invention is based on the objective of providing an improved actuator-drive unit compared to those known from the prior art.

[0005] The problem is solved by an object having the features of claim 1. Consequently, the rotor and the actuator are arranged on a common shaft extending along the actuator axis, such that both the rotor and the actuator are rotatably supported in at least one common bearing point. The rotor and the actuator are at least rotationally fixed to the shaft. It is also possible that the rotor is arranged both rotationally fixed and axially fixed to the actuator shaft. Thus, the rotor and the actuator are connected to each other via the shaft without couplings. According to the invention, the rotor shaft and the actuator shaft are formed or replaced by a shaft, which in particular consists of a single component.The common bearing point of the shaft, and thus of the rotor and the actuator, can provide a radial bearing for the rotor and the actuator, with the rotor and the actuator presumably sharing all bearings of the shaft.

[0006] Thus, the actuator-drive unit has fewer components compared to the prior art. In the prior art, the actuator shaft and the rotor shaft are separate components connected via a coupling, each with its own bearings. By arranging the rotor on the actuator shaft and using common bearing points, not only are the bearings eliminated, but also the coupling between the rotor shaft and the actuator shaft. This allows the unit to be reduced in terms of installation space and weight. Due to the arrangement of the rotor on the actuator shaft, a simpler unit design is achieved. Furthermore, there is no characteristic-curve-dependent force limitation due to an intermediate coupling, as is known from the prior art. Overall, the unit according to the invention is more economical to manufacture.

[0007] Advantageously, the shaft is designed as a continuous shaft, with the rotor and the actuator being located on a common section of the shaft. Consequently, simple manufacturing and virtually loss-free power transmission between the electric motor and the actuator are possible.

[0008] It is further advantageous if the motor is designed as a squirrel-cage or slip-ring rotor motor, particularly as a disc rotor motor. In this design, the rotor is a disc with magnets, especially permanent magnets, arranged on its circular path. The magnets can be located on one of the two axially oriented sides of the disc, so that the magnetic field runs parallel to the rotor axis, or they can be located on the disc's circumferential surface. Alternatively, the coils can be located on the disc rotor and the magnets on the stator, in which case brushes are required to conduct current to the rotor. It is also conceivable to use other electric motors that incorporate an air gap between the rotor and the stator. For example, the motor can be an internal rotor motor, with the rotor located inside the stator.This allows misalignment in the dimension of the air gap to be compensated for.

[0009] Furthermore, an actuator frame can be provided, with the shaft bearings located on the actuator frame. Consequently, the rotor and the actuator can be supported via the shaft in the actuator frame. The actuator frame can be designed as a housing or a frame and have two opposite sides arranged parallel to each other. The bearings can be located on the opposite sides of the actuator frame. The shaft can also extend beyond the actuator frame on one or both sides.

[0010] Furthermore, the stator can be arranged in a stator housing. The stator housing has an opening on one side for receiving the rotor. Advantageously, the actuator assembly can also be detachably attached to the stator housing, particularly by screws or magnets. For maintenance purposes, it is therefore only necessary to detach the stator housing from the actuator assembly to perform work on the rotor or stator, since the stator housing has an opening and the rotor and stator are exposed after the stator housing is removed. Moreover, the arrangement of the rotor on the actuator assembly and the arrangement of the stator in the stator housing facilitates a simpler seal, for example, by allowing a non-magnetic sheet metal plate to be placed between the rotor and the stator, particularly in an air gap between the rotor and the stator.

[0011] It is conceivable that a sufficiently large air gap is provided between the rotor and the stator. This allows the stator housing (36) to be arranged on the actuator frame (20) such that the stator axis (34) and the rotor axis (38) have an axial offset (48) relative to each other. The rotor axis and the stator axis can be arranged parallel or skew to each other. Despite the axial offset, the actuator can be driven by the electric motor without errors and in a stable manner. The compensation of misalignment can be facilitated, in particular, by the air gap between the stator and rotor. It is also conceivable that there is no axial offset between the rotor axis and the stator axis. However, the actuator-drive unit is designed such that an axial offset is possible without errors during operation.Consequently, the assembly of the stator housing and the actuator frame is simplified, as precise alignment of the stator housing with the actuator frame is not required. Rather, it is sufficient that the stator housing can be aligned with the actuator frame within a predefined range. In contrast, prior art requires that the electric motor, i.e., rotor and stator, be aligned in perfect accord for stable operation, and that a coupling be provided between the rotor shaft and the actuator shaft. Such precise alignment and the coupling are unnecessary.

[0012] Furthermore, it is advantageous if the actuator-drive unit is suitable for the electric motor to drive the actuator reliably and stably despite an axial misalignment of up to 5 mm, particularly within a range of 1 mm to 5 mm, between the rotor and stator axes. A slight loss of power is a disadvantage; however, due to the magnetic coupling between the rotor and stator, only minimal loads are exerted on the bearings in the event of an axial misalignment. The aforementioned range also represents a tolerance range for mounting the stator housing to the actuator frame, thus enabling simple and quick assembly.

[0013] It has proven advantageous for the rotor to be arranged at a free end of the shaft. The rotor can form a single component with the shaft or be mounted onto the actuator shaft, in particular by shrink-fitting, pressing, or screwing. Furthermore, it is conceivable that the rotor is arranged on the shaft in another manner. Even a connection via a coupling is conceivable, although, unlike in the prior art, this is not necessary to compensate for misalignment.

[0014] It is further advantageous if the actuator is designed as a flap or has a flap. The flap can be pivoted between an open and a closed position by the electric motor. The arrangement of the flap on the shaft can be used, in particular, to form a diverter valve. This brings into play the advantages of a disc rotor motor, since high torques at low speeds may be required.

[0015] It is also advantageous if the common bearing point of the rotor and the actuator is arranged between the rotor and the actuator.

[0016] Further details and advantageous embodiments of the invention can be found in the following description, which describes and explains in more detail an embodiment of the invention as illustrated in the figures.

[0017] They show: Fig. 1 a schematic sectional view of an actuator-drive unit known from the prior art; Fig. 2 a schematic sectional view of an actuator-drive unit according to the invention; Fig. 2A a schematic sectional view of the electric motor of the actuator-drive unit according to Fig. 2, wherein the rotor axis and the stator axis have an axial offset; Fig. 3 A schematic exploded view of the stator housing and the rotor arranged on the actuator frame according to the unit of the Fig. 2; and Fig. 4 A schematic exploded view of the stator housing and rotor according to the unit of Fig. 2.

[0018] In Fig. Figure 1 shows an actuator-drive unit 10 known from the prior art. The actuator-drive unit 10 comprises an electric motor 12 and an actuator 14. The electric motor 12 comprises a stator 16 and a rotor 18. The actuator 14 is designed as an adjustable flap with a vane 26 and is arranged on an actuator shaft 28. The rotor 18 is arranged on a rotor shaft 30. The actuator shaft 28 and the rotor shaft 30 are designed as separate components and are connected to each other via a coupling 32 in a rotationally fixed manner for the transmission of torque. The coupling 32 is necessary to compensate for an axial misalignment between an actuator axis 46 and a stator axis 34 or rotor axis 38 and provides a characteristic-curve-dependent force limitation of the actuator-drive unit 10.The actuator shaft 14 is rotatably mounted in an actuator frame 20 at a bearing point 22 facing the motor 12 and a bearing point 24 facing away from the motor 12. The rotor shaft 30 is rotatably mounted in a stator housing 36, with a bearing point 31 facing away from the actuator 14 and a bearing point 33 facing the actuator 14 being provided for the rotor shaft 30. The rotor shaft 30 and the actuator shaft 28 do not have common bearing points, since, among other things, the rotor shaft 30 and the actuator shaft 28 can be assigned to two different units.

[0019] The Fig. Figures 2 to 4 show an actuator-drive unit 10 according to the invention, comprising an electric motor 12 and an actuator 14. In the Fig. 2 to 4 are components that correspond to the components of the one in the Fig. The actuator-drive unit 10 shown in Figure 1 corresponds to the corresponding reference numerals. The electric motor 12 comprises a stator 16 and a rotor 18. The stator 16 has a stator axis 34 and is fixedly arranged in a stator housing 36. The rotor 18 is rotatably arranged relative to the stator 16 about a rotor axis 38. To drive the rotor 18, coils 40 are provided on the stator 16, and magnets 44 are arranged on the rotor 18 along a circular path 42 and interact with the coils 40. The magnets 44 are arranged on the circular path 42 such that a north pole and a south pole are formed alternately along the circular path 42. The actuator 14 is rotatably arranged about an actuator axis 46.

[0020] The actuator 14 and the rotor 18 are arranged on a common shaft 29 and are rotationally fixed to the shaft 29, which can be driven by the electric motor 12. The rotor 18 is fixedly arranged at a free end 52 of the shaft 29. The actuator 14 is arranged along the area of ​​the shaft 29 between the free ends 52 of the shaft 29. Unlike the arrangement described in the Fig. In the actuator-drive unit 10 shown in Figure 1, the actuator 14 and the rotor 18 are thus jointly supported at bearing points 22 and 24 via the shaft 29. It is evident that the rotor 18 and the actuator 14 are not supported at separate bearing points. Furthermore, no coupling is arranged between the actuator 14 and the rotor 18, since the actuator 14 and the rotor 18 are arranged on the continuous shaft 29. Therefore, fewer components are required to drive the actuator 14 than are necessary according to the prior art. In addition, both installation space and weight can be saved.

[0021] The shaft 29 is designed as a continuous shaft and extends from bearing 24 to bearing 22. The rotor 16 and the actuator 14 therefore share common bearings 22 and 24. Furthermore, the shaft 29 projects beyond the actuator frame 20 at bearing 24 and at bearing 22. The shaft 29 also has two free ends 52, with the rotor 18 arranged at one of these free ends 52. The shaft 29 includes a shoulder 56 in the area of ​​bearings 22 and 24, but is nevertheless considered a continuous shaft 29 with a single shaft section.

[0022] The bearing points 22, 24 of the shaft 29 are provided in the actuator frame 20. The actuator frame 20 comprises two opposing sides 21, which define a path 25 arranged between the sides 21. The actuator 14, designed as a flap, includes a leaf 26, which is configured to open and close the path 25 in the actuator frame 20. The flap can be moved into an open position and a closed position by the electric motor 12.

[0023] For mounting the electric motor 12, the stator 16 with the stator housing 36 is arranged on the actuator frame 20. The actuator frame 20 has holes into which screws or pins of the stator housing 36 can engage. It is also conceivable that magnets are provided on the stator housing 36 for attaching the stator housing 36 to the actuator frame 20. Increased flexibility in mounting the stator housing 36 on the actuator frame 20 results from the fact that the rotor axis 38 forms a [missing information - likely a specific orientation] relative to the stator axis 34. Fig. The axis offset 48 shown in Figure 2A is possible. Consequently, only a rough alignment of the stator housing 36 on the actuator frame 20 is sufficient during assembly. Misalignment errors between the stator 16 or stator axis 34 and the rotor 18 or rotor axis 38 can be compensated for by the air gap 50. Furthermore, the load on the bearings is reduced by the magnetic coupling between the rotor 18 and stator 16 in the case of an axis offset 48. Stable operation of the electric motor 12 is possible with an axis offset 48 that corresponds to up to 1 / 3 of the magnet length, in particular up to 5 mm, where the magnet length corresponds to the radial extent of the magnets. For repair or maintenance purposes of the motor 12, only the stator housing 36 needs to be removed, as this exposes the rotor 18 and the stator 16. Consequently, one step can be saved compared to the prior art during assembly or disassembly.

[0024] In the Fig. 2 The stator housing 36 is arranged on the actuator frame 20 such that the stator axis 34 lies in the rotor axis 38. In the Fig. In the embodiment shown in Figure 2, the rotor axis 38 is also located in the actuator axis 46, since the actuator 14 and the rotor 18 are each arranged directly and without coupling at a free end 52 of the shaft 29.

[0025] To illustrate a possible axis offset 48, it shows Fig. 2A a detailed view of the in Fig. 2 shown actuator-drive unit 100, in which, among other things, the stator housing 36 with the stator 16 and the rotor 18 are visible. In contrast to the Fig. 2 is in Fig. 2A An axis offset 48 is provided between the stator axis 34 and the rotor axis 38. In addition to an axis offset 48, it is also conceivable that the stator axis 34 and rotor axis 38 are arranged at an angle and / or skew to each other.

[0026] In Fig. 2 and Fig. Figure 4 shows that the stator housing 36 has a recess 37 for receiving the rotor 18. The recess 37 is designed such that the stator housing 36 can only be mounted on the actuator frame 20 within the assembly tolerance, by limiting the orientation of the stator housing 36 perpendicular to the rotor axis 38 with respect to the rotor 18 by means of two stops 39 arranged parallel to the rotor axis 38 on the stator housing 36.

[0027] As in the Fig. 3 and Fig. Figure 4 shows, on the one hand, the rotor 18 and, on the other hand, the stator housing 36. Fig. Figure 4 shows that the rotor 18 connects directly to the free end 52 of the shaft 29, so that the shaft 29 is concealed here. Arranging the rotor 18 on the shaft 29 results in a slight widening of the actuator frame 20, whereby, at least in this embodiment, the rotor 18 can be associated with the actuator frame 20. The stator housing 36 is designed such that it can be arranged directly on the actuator frame 20. Furthermore, the connecting elements or the stator housing 36 are designed such that an air gap 50 remains between the rotor 18 and the stator 16. Despite the air gap 50, it is possible to drive the rotor or the shaft 29 and the actuator 14. Due to the design of the electric motor 12 as a disc rotor motor 12, misalignment errors when arranging the stator 16 on the rotor 18 can thus be compensated for.

[0028] In Fig.Figure 3 shows a view into the stator housing 36 with the stator 16. It can be seen that the coils 40 are also arranged along a circular path 42. Furthermore, magnetic field elements 54 are provided to align the magnetic field formed by the coils 40 or to direct it specifically towards the rotor 18.

Claims

[1] Actuator-drive unit (10) comprising an actuator (14) rotatable about an actuator axis (46), and an electric motor (12) driving the actuator (14) with a stator (16) and with a rotor (18), wherein the stator (16) has a stator shaft (34) and is arranged in a fixed position, wherein the rotor (18) is arranged to be rotatable relative to the stator (16) about a rotor axis (38), wherein to drive the rotor (18) and thus the The actuator (14) has coils (40) on the stator (16) and magnets (44) arranged along a circular path (42) on the rotor (18) which interact with the coils (40), wherein the rotor (18) and the actuator (14) are arranged on a common shaft (29) extending along the actuator axis (46), wherein the rotor (18) and the actuator (14) are connected to the shaft (29) in a rotationally fixed manner, so that the rotor (18) and the actuator (14) are rotatably mounted on the shaft (29) in at least one common bearing point (22, 24), characterized by , that an actuator frame (20) is provided and that at least one common bearing point (22, 24) is arranged on the actuator frame (20), that the stator (16) is arranged in a stator housing (36) which can be detachably arranged on the actuator frame (20), and that a sufficiently large air gap is provided between the rotor (18) and the stator (16) such that the stator housing (36) can be arranged on the actuator frame (20) such that the stator axis (34) and the rotor axis (38) have an axis offset (48) to each other. [2] Actuator-drive unit (10) according to claim 1, characterized by , that the wave (29) is formed as a continuous wave (29). [3] Actuator-drive unit (10) according to claim 1 or 2, characterized by, that the motor (12) is designed as a squirrel-cage rotor or as a slip-ring rotor, in particular as a disc rotor motor. [4] Actuator-drive unit (10) according to any one of the preceding claims, characterized by , that the actuator-drive unit (10) is designed such that the motor (12) can reliably drive the actuator (14), wherein the axis offset (48) has a value that corresponds to up to 1 / 3 of a magnet length corresponding to the radial extent of the magnets (44). [5] Actuator-drive unit (10) according to any one of the preceding claims, characterized by , that a sealing element, in particular a non-magnetic sealing plate, is provided between the rotor and the stator for sealing the stator housing and / or the rotor. [6] Actuator-drive unit (10) according to any one of the preceding claims, characterized by , that the rotor (18) is arranged at a free end (52) of the shaft (29). [7] Actuator-drive unit (10) according to any one of the preceding claims, characterized by , that the actuator (14) is arranged along the axial extent of the shaft (29) on the shaft (29). [8] Actuator-drive unit (10) according to any one of the preceding claims, characterized by , that the actuator (14) is designed as a flap or with a flap comprising a wing (26), wherein the flap can be pivoted between an open position and a closed position by the motor (12). [9] Actuator-drive unit (10) according to any one of the preceding claims, characterized by , that a common bearing point (22) is arranged between the rotor (18) and the actuator (14). [10] Actuator-drive unit (10) according to any one of the preceding claims, characterized by , that the rotor (18) is arranged between the stator (16) and the actuator (14).

Images