Friction brake unit, drive brake unit and vehicle

Abstract

The present invention relates to a friction brake unit (1) for a drive brake unit. The friction brake unit (1) comprises at least two components (4, 5) that can be electrically connected to a vehicle. The aim is to save limited installation space in the area of ​​the wheel suspension and to simplify assembly. For this purpose, the friction brake unit (1) includes a connection element (6) that has a common connection geometry (7) for the at least two components (4, 5) that can be electrically connected to a vehicle. This saves installation space and simplifies the connection of the friction brake unit. The invention further relates to a drive brake unit comprising a wheel-integrated electric motor and such a wheel-integrated friction brake unit (1), as well as a vehicle comprising at least two drive brake units of this type.

Description

The present invention relates to a friction brake unit for a drive brake unit, wherein the friction brake unit comprises at least one brake actuator for actuating the friction brake unit and generating a braking torque, and wherein the friction brake unit comprises at least two components that can be electrically connected to a vehicle. The invention further relates to a drive brake unit comprising a wheel-integrated electric motor and a previously mentioned wheel-integrated friction brake unit. Finally, the invention relates to a vehicle comprising at least two of the aforementioned drive brake units. For the purposes of this application, the term "drive brake unit" refers to a combination of an electric motor and a friction brake unit. Such a drive brake unit is known, for example, from KR20230021347A, in which a disc brake with a fixed caliper is combined with a wheel-integrated electric motor. The drive brake unit has a multitude of connections for power supply, signal connection of the electric motor, cooling of the drive brake unit, and hydraulic lines for the brake caliper. When integrating friction brakes and electric motors into wheel-integrated drive brake units, as described, it quickly becomes necessary to connect a large number of power supply lines, signal lines and fluid lines in a very small space, which then compete for installation space with the wheel suspension and springs. The invention is therefore based on the objective of providing a friction brake unit that at least partially solves the aforementioned problem. According to the invention, this problem is solved by a friction brake unit according to claim 1, a drive brake unit according to claim 12, and a vehicle according to claim 16. Accordingly, the friction brake unit mentioned above is provided, comprising a connection element that has a common connection geometry for the at least two components that can be electrically connected to a vehicle. This allows at least some of the electrical connection lines to be consolidated into common cables or cable harnesses. Furthermore, the position of the connection geometry can be varied within a certain range and thus adapted to the spatial conditions in the area of ​​the steering knuckle and the wheel suspension, so that the cable(s) to be connected to the connection geometry can be connected with as little space as possible. This also simplifies assembly and maintenance. The term "electrically connectable component to a vehicle" is to be understood as meaning that the component requires a connection to a power supply and / or an electrical signal connection for its intended function. In this document, "engine rotation axis," "axial," or "axial direction" refers to the direction parallel to the axis of rotation of the vehicle wheel or drive rotor, while "radial" or "radial direction" refers to the direction(s) perpendicular to the aforementioned axis of rotation. The direction of rotation / circumference refers to the tangential directions along imaginary circular paths of constant radius around the engine rotation axis in planes perpendicular to the engine rotation axis. Preferably, the connection geometry is designed so that at least two components can be connected to the vehicle via a single cable. This also simplifies installation. In one embodiment, an electrically connectable component to a vehicle is an electrically actuated parking brake device. Depending on the type of parking brake device, several electrical cables may need to be connected to the friction brake unit in the prior art. The invention offers corresponding advantages for friction brake units with integrated parking brake devices during assembly and maintenance. It is preferred if the electrically actuated parking brake device comprises a parking brake actuator integrated into a hydraulically actuated service brake actuator. Such service brakes with an integrated parking brake device have additional components that are electrically connected to the vehicle and benefit from the present invention. Preferably, the electrically actuated parking brake device is integrated as a transmission lock into an electromechanically actuated service brake actuator. Compared to hydraulic brakes, such fully electric friction brake units have at least an additional power supply and, in many cases, additional signal and sensor lines, which would require separate cable connections in the prior art and which are particularly advantageous according to the invention. In one embodiment, a component electrically connectable to a vehicle is a brake pad wear indicator. Visual inspection of brake pad wear may not be possible, depending on the design of the drive brake unit. However, even when the friction brake unit is designed to last the lifetime of the drive brake unit (i.e., no need to replace the brake pads under normal circumstances), a brake pad wear indicator may be necessary for safety reasons. Accordingly, such a friction brake unit benefits from the solution according to the invention, as the additional cable connection can be consolidated. Preferably, a component that can be electrically connected to a vehicle is a brake force sensor or brake torque sensor. These sensors can also be connected to a local control unit. If not, the friction brake unit with sensor benefits from the proposed solution. Preferably, the connection element is designed as a housing cover that is part of a friction brake housing. This allows, on the one hand, the consolidation of component connections for electrically connected components within the housing cover. On the other hand, depending on the friction brake unit, adapted housing covers can be provided to consolidate the connections of various components. In one embodiment, the connection element comprises, on a side facing the friction brake unit, intermediate geometries for at least two of the components electrically connectable to a vehicle, which can be connected to component terminals of the components, wherein the electrical leads from the intermediate geometries in the connection element are joined in the common connection geometry. If the connection element is a housing cover of a friction brake housing, the intermediate geometries can be arranged on the inside of the housing cover, while the common connection geometry is arranged on an outside (facing the vehicle) of the friction brake housing. Preferably, the friction brake housing of the friction brake unit comprises an elastically deformable sealing element that allows movement of the friction brake housing during actuation of the brake actuator. Such a solution can be particularly advantageous when the installation space around the friction brake is very limited, but sealing of the friction brake unit is still desired. The movement of the friction brake housing during actuation of the brake actuator can, for example, be elastic deformation during the actuation process. However, it is also possible that the movement of the friction brake housing during actuation of the brake actuator describes long-term movement of the friction brake housing due to brake pad wear. For instance, with significantly worn brake pads, the brake actuator has a longer maximum travel distance than with new brake pads, which has a corresponding influence on the deformation of the friction brake housing. Preferably, the connecting element is arranged to be movable together with an elastically deformable sealing element. It is preferred if the friction brake unit is a disc brake with a brake caliper designed as a floating caliper. The problem according to the invention is further solved by a drive brake unit comprising a wheel-integrated electric motor and a wheel-integrated friction brake unit according to one of the preceding embodiments, wherein the friction brake unit is preferably arranged at least partially axially overlapping with the electric motor along the motor rotation axis. Preferably, a friction brake housing of the friction brake unit is sealed to a stator component of the wheel-integrated electric motor, thus essentially preventing brake dust from escaping the drive brake unit. The friction brake unit can be arranged in a sufficiently large friction brake housing to allow the brake actuator a full axial stroke within the housing. A sealing element between the connection element and the stator component can then simply serve a sealing function without needing to allow the axial stroke of the friction brake housing. Alternatively, an elastically deformable sealing element can be provided between the connection element and the stator component, allowing elastic deformation of the friction brake housing during actuation of the brake actuator.“Essentially prevented” can be understood here to mean that at least half, preferably over 90%, of the brake dust is retained. In one embodiment, the electric motor is a double-rotor radial flux motor in which a drive stator is arranged radially between an outer drive rotor and an inner drive rotor, the drive stator comprising coils for generating a magnetic field. Permanent magnets can be arranged on both the outer and inner drive rotors, facing the drive stator. Such wheel-integrated electric motors exhibit particularly high average efficiency (even in the low-load range). The outer and inner drive rotors can be connected via a rotor base. The rotor base and outer drive rotor can jointly have a pot shape, with the outer and inner drive rotors extending axially from the rotor base. The outer drive rotor and the rotor base can be manufactured in one piece. The inner drive rotor can be attached to the rotor base as an axially extending flange.A base plate extending essentially in a radial direction can support the drive stator. The base plate, the external drive rotor, and the rotor base can essentially form a motor housing. Preferably, the drive brake unit includes a wheel-integrated inverter designed to convert vehicle-side direct current into alternating current for the electric motor. This solution allows the use of smaller diameter cables (low-voltage DC cables) to power the wheel-integrated electric motor. This saves further installation space in the area of ​​the wheel suspension / steering knuckle. Preferably, the drive brake unit includes active liquid cooling, which comprises a cooling channel in a base plate of the electric motor that supports the drive stator. Active liquid cooling allows for even better protection of the heat-sensitive components (especially permanent magnets and the electronics) of the drive brake unit from high temperatures. Preferably, the drive / brake unit is designed as a direct drive and does not include a wheel-integrated gearbox. The problem according to the invention is finally also solved by a vehicle comprising at least two drive brake units according to one of the above embodiments. Further details of the invention will become apparent from the description of the illustrated embodiments and the attached claims. The drawings show: Fig. 1 an isometric partially exploded view of a first embodiment of a friction brake unit according to the invention, and Fig. 2 an isometric view of the first embodiment according to Fig. 1, Fig. 3 a partial view of a drive brake unit according to the invention comprising a friction brake unit according to Fig. 1 and Fig. 2, and Fig. 4 an isometric view of a second embodiment of a friction brake unit according to the invention. In the following detailed description of preferred embodiments, the same reference numerals denote essentially identical or identical parts in or on these embodiments. However, for better clarity of the invention, the preferred embodiments shown in the figures are not always drawn to scale. Figures 1-3 show a first embodiment of the friction brake unit 1 according to the invention, while Figure 4 shows a second embodiment of the friction brake unit 1 according to the invention. In Figure 3, the friction brake unit 1 is integrated into a drive brake unit 2 according to the invention. The friction brake unit 1 comprises at least one brake actuator 3 for actuating the friction brake unit and generating a braking torque. The friction brake unit 1 comprises at least two components 4, 5 that can be electrically connected to a vehicle. In the embodiment shown in Fig. 1 and Fig. 2, one component is a brake pad wear indicator 4. The brake pad wear indicator 4 is designed here to detect wear in both brake pads of a brake caliper. Another component is an electrically actuated parking brake device 5 (the reference numeral 5 in Fig. 1 points to the electrical component connection 12 of the parking brake device 5, since this is integrated into the brake actuator). The friction brake unit 1 comprises a connection element 6 that has a common connection geometry 7 for the at least two components 4, 5 that can be electrically connected to a vehicle. In Fig. 1, Fig. 2 to Fig. 3, the connection element 6 is designed as a housing cover 6, which is part of a friction brake housing 8. In the embodiment of Fig. 4, the connecting element 6 is integrated into the friction brake housing 8. As shown in Fig. 1, the connection element 6 comprises, on one side facing the friction brake unit 1, intermediate geometries 9, 10 for at least two of the components 4, 5 that can be electrically connected to a vehicle, which can be connected to component terminals 11, 12 of the components 4, 5. The electrical leads from the intermediate geometries 9, 10 are brought together in the connection element 6 in the common connection geometry 7. In the first embodiment shown in Figures 1-3, the friction brake housing 8 of the friction brake unit 1 includes an elastically deformable sealing element 13 (shown only in Figure 3) that allows elastic deformation of the friction brake housing 8 when the brake actuator 3 is actuated. The sealing element 13 is designed here as an axially extendable bellows. Thus, the connecting element 6, together with the elastically deformable sealing element 13, is movably arranged and can follow the actuation of the brake actuator 3. A sealing connection geometry 14 is provided in both embodiments of Figs. 1-3 and Fig. 4. In the second embodiment of Fig. 4, the sealing element 13 can, for example, be a sealing ring (e.g., an O-ring). The friction brake unit 1 is a disc brake with a floating caliper. The caliper comprises an axially displaceable caliper housing 15 and a static brake holder 16 for guidance and support. Figure 3 shows the drive brake unit 2 with integrated friction brake unit 1. A wheel-integrated electric motor is arranged with the friction brake unit 1 along a motor rotation axis, at least partially axially overlapping. The friction brake housing 8 of the friction brake unit 1 is sealedly connected to a stator component 17 of the wheel-integrated electric motor, thus essentially preventing brake dust from escaping the drive brake unit 2. The stator component 17 is a base plate 17 extending essentially radially. The base plate 17 can, for example, also support a drive stator with windings or coils for generating an alternating magnetic field of the electric motor. A drive torque can be generated through the interaction of the alternating magnetic field of the drive stator with the magnetic field of permanent magnets arranged on a drive rotor. The base plate 17, an external drive rotor 18, and a rotor base (rear side of Fig. 3, not shown) can essentially form a motor housing.The electric motor in question is a double-rotor radial flux electric motor, wherein an inner drive rotor is arranged radially inside the drive stator. The drive brake unit also includes a wheel-integrated inverter 19, which is designed to convert vehicle-side direct current into alternating current for the electric motor. Reference symbol list: 1 Friction brake unit 2 Drive brake unit 3 Brake actuator 4 Pad wear indicator / Component 5 Parking brake device / Component 6 Connection element / Housing cover 7 Connection geometry 8 Friction brake housing 9 Intermediate geometry 10 Intermediate geometry 11 Component connection 12 Component connection 13 Sealing element 14 Seal connection geometry 15 Caliper housing 16 Brake holder 17 Stator component / Base plate 18 External drive rotor 19 Inverter QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature KR 20230021347A

[0003]

Claims

Friction brake unit (1) for a drive brake unit (2), wherein the friction brake unit (1) comprises at least one brake actuator (3) for actuating the friction brake unit (1) and generating a braking torque, wherein the friction brake unit (1) comprises at least two components (4, 5) that can be electrically connected to a vehicle, characterized in that the friction brake unit (1) comprises a connection element (6) that has a common connection geometry (7) for the at least two components (4, 5) that can be electrically connected to a vehicle. Friction brake unit (1) according to claim 1, characterized in that the connection geometry (7) is designed such that at least two components (4, 5) can be connected to the vehicle via a single cable. Friction brake unit (1) according to claim 1 or 2, characterized in that an electrically connectable component (5) to a vehicle is an electrically actuated parking brake device (5). Friction brake unit (1) according to claim 3, characterized in that the electrically actuated parking brake device (5) comprises a parking brake actuator which is integrated into a hydraulically actuated service brake actuator. Friction brake unit (1) according to claim 3, characterized in that the electrically actuated parking brake device (5) is integrated as a transmission lock into an electromechanically actuated service brake actuator. Friction brake unit (1) according to one of the preceding claims, characterized in that an electrically connectable component (4) to a vehicle is a pad wear indicator (4). Friction brake unit (1) according to one of the preceding claims, characterized in that an electrically connectable component (4, 5) to a vehicle is a brake force sensor or brake torque sensor. Friction brake unit (1) according to one of the preceding claims, characterized in that the connecting element (6) is designed as a housing cover (6) which is part of a friction brake housing (8). Friction brake unit (1) according to one of the preceding claims, characterized in that the connection element (6) on a side facing the friction brake unit (1) comprises intermediate geometries (9, 10) for at least two of the components (4, 5) that can be electrically connected to a vehicle, which can be connected to component connections (11, 12) of the components (4, 5), wherein the electrical lines from the intermediate geometries (9, 10) in the connection element (6) are brought together in the common connection geometry (7). Friction brake unit (1) according to one of the preceding claims, characterized in that a friction brake housing (8) of the friction brake unit (1) comprises an elastically deformable sealing element (13) that enables movement of the friction brake housing (8) during actuation of the brake actuator (3). Friction brake unit (1) according to one of the preceding claims, characterized in that the friction brake unit (1) is a disc brake with a brake caliper designed as a floating caliper. Drive brake unit (2) comprising a wheel-integrated electric motor and a wheel-integrated friction brake unit (1) according to one of the preceding claims, wherein the friction brake unit (1) is preferably arranged along the motor rotation axis (A) at least partially axially overlapping with the electric motor. Drive brake unit (2) according to claim 12, characterized in that a friction brake housing (8) of the friction brake unit (1) is sealedly connected to a stator component (17) of the wheel-integrated electric motor, so that the escape of brake dust from the drive brake unit (2) is substantially prevented. Drive brake unit (2) according to claim 12 or 13, characterized in that the electric motor is a double rotor radial flux motor in which a drive stator is arranged radially between an outer drive rotor (18) and an inner drive rotor, wherein the drive stator comprises coils for generating a magnetic field. Drive brake unit (2) according to one of the preceding claims, characterized in that the drive brake unit (2) comprises a wheel-integrated inverter (19) which is configured to convert vehicle-side direct current into alternating current to the electric motor. Vehicle comprising at least two drive brake units (2) according to claims 12 to 15.

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