Actuator with power electronics

Abstract

Actuator (1, 1a, 1b), in particular hydrostatic actuator, for a motor vehicle with a rotor (3) and a stator (4) with at least one winding (8) and a circuit board (6, 6a, 6b) controlling the current supply to the at least one winding (8) and at least one connection (9) of the at least one winding (8) to the circuit board (6, 6a, 6b), wherein at least one compensating element (11, 11a) is connected to the circuit board (6, 6a, 6b) with a cantilever (12) following the path of the at least one connection (9) passing through the circuit board (6, 6a, 6b), and the at least one connection (9) and the cantilever (12) are electrically connected to each other on the side of the circuit board (6, 6a, 6b) facing away from the at least one winding (8), the at least one compensating element (11, 11a) by means of three uniformly spaced Mounting pins (13, 13a) are attached to the circuit board (6, 6a, 6b), and between a,The central part (15) receiving the boom (12) and the fastening pins (13, 13a) each has a curved arm (17, 17a), characterized in that the respective arm (17, 17a) is curved in a plane parallel to the circuit board (6, 6a, 6b).

Description

[0001] The invention relates to an actuator, in particular a hydrostatic actuator, for a motor vehicle with a rotor and a stator with at least one winding and a circuit board controlling the current supply to the at least one winding and at least one connection of the at least one winding to the circuit board.

[0002] Actuators in motor vehicles are used for the mechanical displacement of components relative to one another. This displacement is controlled by a controller. If the actuator is electrically operated, power electronics are also included, which supply one or more windings of an electric motor with electrical energy in a controlled manner. This requires the winding(s) to be connected to the circuit board.

[0003] WO 2011 / 127 888 A2 discloses an actuator in the form of a so-called hydrostatic actuator, in which an electric motor, via a gearbox such as a planetary roller gear, drives a master cylinder, which in turn actuates a slave cylinder via a hydraulic system. The circuit board with the power electronics is located on the front face of the hydrostatic actuator housing. The stator of the electric motor has three windings, which are controlled by the power electronics on the circuit board. The winding connections are connected to the circuit board. The unpublished German patent application No. 10 2014 210 973.3 shows a more precise connection of the hydrostatic actuator's terminals to the circuit board, in that the terminals between the point where they exit the windings and the circuit board have a curved shape to, for example, compensate for temperature-related length changes.

[0004] From DE 10 2004 027 653 A1 an electric motor is known in which connections of windings are recorded on a terminal board of the housing.

[0005] The object of the invention is the further development of an actuator, in particular a hydrostatic actuator. In particular, the object of the invention is to achieve a robust and tolerance-compensating fastening of a connection of a winding of the actuator to the circuit board.

[0006] Further connection options for cables, e.g. from electric motors or actuators with circuit boards or similar, are known from DE 10 2009 053 426 A1, EP 1 700 516 B1, DE 10 2013 105 571 A1, DE 20 2005 016 915 U1 or DE 102 29 606 A1.

[0007] The problem is solved by the subject matter of claim 1. The dependent claims describe advantageous embodiments of the subject matter of claim 1.

[0008] The proposed actuator is intended for use in a motor vehicle and comprises a rotor and a stator with at least one winding and a printed circuit board (PCB) that controls the electric motor. The actuator can be designed as a hydrostatic actuator, the rotor of which actuates a piston of a master cylinder via a gearbox, for example, a planetary roller gearbox. The master cylinder is connected to a slave cylinder via a hydrostatic linkage. The slave cylinder can actuate a friction clutch, a brake, or the like. The circuit board can contain power electronics for controlling the electric motor, whereby the winding(s) can be energized according to a predetermined setpoint. If multiple windings are present, the electric motor can be electronically commutated. The at least one winding has two terminals, with at least one terminal being integrated into the circuit board and energized by the power electronics.The other connection can be mounted on the circuit board or a common base. To accommodate the at least one connection on the circuit board, at least one compensating element is attached to the board. The at least one compensating element has a projection that can extend, for example, perpendicular to the surface of the circuit board. The connection is guided, for example, through an opening in the circuit board. The projection follows the path of the at least one connection. The at least one connection and the associated projection are electrically connected to each other on the side of the circuit board facing away from the at least one winding.

[0009] For example, a stator may have two, three, or more windings. For instance, a stator with three windings may have three terminals, each offset by 120°, and associated compensating elements. In the following description, one or more terminal elements, terminals, and / or windings refer to at least one compensating element, at least one terminal, and at least one winding, respectively.

[0010] The connection of a winding can be designed as winding wire, a stamped grid, or the like. The electrical connection between the connection and the cantilever can be made, for example, by soldering, crimping, or similar methods. Furthermore, a mechanical and / or electrical connection between the cantilever and the connection can be provided by means of a resistance welding process. To achieve a spatially defined weld point, for example, the cantilever can have a weld projection. A weld projection is understood to be a raised area on the cantilever, for example, embossed, pressed from, flared, or similarly produced, relative to the rest of the surface.

[0011] The compensating element can be located on the side of the circuit board facing either the winding or the other side. The compensating element can be electrically and mechanically connected to this side, for example, by soldering. Furthermore, the compensating element can have at least one or more, for example, three, mounting pins that extend through corresponding openings in the circuit board. These mounting pins can be attached by soldering, crimping, snap-fit, using a press-fit connection, or similar methods. If the compensating element is located on the side of the circuit board facing the winding, the mounting pins and extensions can be oriented in the same direction, with each mounting pin extending through one opening in the circuit board and the extension through another opening.For routing the connection of a winding and its associated extension through the circuit board, different openings or a single opening may be provided. If the compensating element is attached to the side of the circuit board facing away from the winding, the mounting pins and extension point in the opposite direction; the extension does not need to pass through the circuit board. The connection is routed through an opening in the circuit board.

[0012] According to the invention, the arrangement of several fastening pins is uniform. For example, three fastening pins can be arranged uniformly around an imaginary center point at intervals of 120°. The cantilever can be provided between two fastening pins.

[0013] Between a fastening pin and a central part of the compensating element, a tolerance-compensating means, according to the invention a curved arm, is provided. The arm can be S-shaped. Material-weakening cuts can be provided between the fastening pin and the central part to form an arm or a similar connection. The extension can be arranged on the central part or on a fastening pin.

[0014] The compensating element can be manufactured using a stamping and bending process. It can be made of a highly electrically conductive material, such as copper, a copper-tin alloy, or similar materials. The surface of the compensating element can be electroplated to improve electrical conductivity, corrosion protection, and / or other properties. To compensate for changes in length, particularly under varying temperatures, the connections between the windings and the circuit board can be designed with a length compensation device. For example, the connections can be curved, such as an S-shape.

[0015] The invention is described in relation to the invention described in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. The exemplary embodiment shown in section 6 is explained in more detail. The following are shown: Fig. 1 a partial cut through an actuator, Fig. 2 a view of the actuator housing of the Fig. 1 looking at the circuit board, Fig. 3 a 3D view of a leveling element, Fig. 4 a 3D view of the compensation element of the Fig. 3 from a different perspective, Fig. 5 opposite the fastening pins of the compensating element of the Fig. 3 and Fig. 4 modified mounting pins and Fig. 6 a top view of the opened housing with circuit board of an opposing actuator 1, 1a of the Fig. 1 and Fig. 2 modified actuators

[0016] Fig. Figure 1 shows a partial section through the actuator 1, which can be designed, for example, similarly to the hydrostatic actuator according to WO 2011 / 127 888 A2. The actuator 1 comprises the electric motor 2 with the rotor 3 and the stator 4, which is housed in the casing 5. At the end face of the electric motor 2, within the casing 5, is the circuit board 6 with the connector 7. The circuit board 6 supplies power to and controls the electric motor 2. For this purpose, the individual windings 8 of the stator 4 are energized. The three windings 8 provided here each have terminals 9. The terminals 9 extend through openings 10 in the circuit board 6. To save space and compensate for tolerances, compensating elements 11 are attached to the circuit board 6 for each terminal 9. These compensating elements have a projection 12 that extends essentially perpendicular to the circuit board 6.The terminals 9, which also extend essentially perpendicularly through the circuit board 6, are mechanically and electrically connected to the arms 12. The terminals 9 can be stress-relieved, for example, by a curved or bent guide between the windings 8 and the circuit board 6.

[0017] Fig. Figure 2 shows a slightly modified actuator 1a with the slightly modified circuit board 6a. The actuator 1a is designed as a dual actuator, for example for actuating two friction clutches of a dual clutch, wherein two individual – essentially identical – actuator units are housed in a common casing 5a. This corresponds to the actuator 1 of the Fig. Actuator 1a, or each actuator assembly, comprises an electric motor with a stator having three windings. The terminals 9 of the stator extend through openings 10a in the circuit board 6a and are mechanically and electrically connected to the arms 12. The arms 12 of the compensating elements 11 extend through the same openings 10a in the circuit board 6a. The compensating elements 11 are mounted on the circuit board 6a on the back side, i.e., on the side facing the windings, by means of the mounting pins 13. They are attached to the circuit board 6a, for example, by soldering the mounting pins 13 or by means of a press-fit connection. The mounting pins 13 extend through openings 14 in the circuit board 6a.

[0018] The Fig. 3 and Fig. Figure 4 shows the compensating element 11 of the Fig. 1 and Fig. Figure 2 shows a 3D view from different angles. The compensating element 11 has a plate-shaped central part 15, which allows the compensating element 11 to be placed on the circuit board. In the illustrated embodiment, fastening pins 13 are evenly distributed around the circumference at an angle of 120° around a center point of the central part 15, for example, around the opening 16. The fastening pins 13 can, for example, be soldered through openings 14 ( Fig. 2) brought and electrically connected to one or more layers of the circuit board, for example by soldering, whereby a mechanical fastening to the circuit board is achieved by the solder point formed on the surface of the circuit board. Curved arms 17 are formed between the fastening pins 13 and the central part 15, which allow for tolerance compensation, for example in the case of changing temperatures during operation or during assembly.

[0019] The extension arm 12 is arranged between two mounting pins 13. To attach the compensating elements 11 to the back of the circuit board, the mounting pins 13 and the extension arm 12 are folded essentially perpendicularly in the same direction and extend through correspondingly shaped openings 10, 14 of the circuit board 6a ( Fig. 2) The boom 12 has, in the area of ​​its longitudinal extension, preferably in the area of ​​its free end, the weld boss 18, which has a defined contact surface such as a weld surface opposite the connection 9 ( Fig. 2) exhibits. In this way, for example, a connection essentially limited to the weld projection 18, such as welding or brazing the boom 12 to the connection 9, can be made using a resistance welding process ( Fig. 2) be achieved.

[0020] The compensating element 11 is manufactured from suitable sheet metal, for example copper or its alloys, in particular a copper / tin alloy (Cu-Sn). To produce a surface suitable for electronic applications, the compensating elements can additionally be, for example, electroplated. The bent or curved arms 17 are produced by cutting out corresponding slots 19, 20. In the illustrated embodiment, a slot 19 near the central part 15 and a slot 20 near the fastening pin are provided, resulting in a substantially S-shaped design of the arms 17. The weld boss 18 is produced, for example, by embossing or raising a section of the sheet metal. The fastening pins 13 and the extension 12 are folded over from the previously preferably flat sheet metal section relative to the central part 15.

[0021] The Fig. Figure 5 shows a detail of a compensating element 11 opposite the Fig. 3 and Fig. 4 modified compensating element 11a. In contrast to the compensating element 11, the fastening pins 13a of the compensating element 11a are designed as press-fit connections 21a. For example, in the Fig. Figure 5 shows a fastening pin 13a of a compensating element 11a that otherwise corresponds to the compensating element 11. The press-fit connection 21a comprises two bulbous expanding elements 22a arranged essentially perpendicular to the arms 17a, which are pressed through a correspondingly formed opening in the circuit board by elastic compression and subsequently expand again, so that a locking action with the circuit board takes place at the fastening pins 13a.

[0022] The Fig. Figure 6 shows another one, opposite actuators 1, 1a of the Fig. 1 and Fig. 2. Modified variant in the form of actuator 1b with a view of the opened housing 5b with the circuit board 6b attached to it and with the electric motor not yet attached. On the circuit board 6b, three compensating elements 11 are provided, distributed around the circumference at an angle of 120° relative to the center point M. To illustrate the arrangement of these, the elements, which are normally hidden by the circuit board 6b because they are located on the side facing away from the visible side of the circuit board 6b, are shown in outline. In the area of ​​the arms 12, the openings 10b are arranged, through which the arms 12 project towards the visible side of the circuit board 6b, and through which the winding connections (not shown) project. Connections and the weld bumps 18 ( Fig. 3 and Fig. 4) are electrically connected to each other in the manner shown. Reference symbol list 1 actuator 1a Actuator 1b Actuator 2 electric motors 3 Rotor 4 Stator 5 cases 5a Housing 5b Housing 6 circuit boards 6a circuit board 6b circuit board 7 connector plugs 8 windings 9 connection 10 Opening 10a Opening 10b Opening 11 Compensating element 11a Compensating element 12 outriggers 13 fastening pin 13a Mounting pin 14 Opening 15 Central part 16 Opening 17 Arm 17a Arm 18 sweat bumps 19 slots 20 slots 21a Pressfit connection 22a Spreading element M Center

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