Drive brake unit and vehicle

Abstract

The invention relates to a drive brake unit (1) comprising a wheel hub motor and a drum brake. The drum brake comprises a brake drum and a brake unit housed within the brake drum. The drive brake unit (1) includes a base plate (3) to which a drive stator is attached, with the brake unit (4) arranged on a first side (5) of the base plate (3). The brake unit (4) is configured for mechanical connection with a vehicle interface of a vehicle located on a second side (6) of the base plate (3) opposite the first side (5). The invention aims to provide a drive brake unit with improved integration of the wheel hub motor and the drum brake.For this purpose, at least one sealing element (7) is arranged between at least one component of the drum brake and an opening (9) extending through the base plate (3) to seal the first side (5) against the second side (6). This seals the drive brake unit against water ingress and brake dust escape.

Description

[0001] The present invention relates to a drive brake unit comprising a wheel hub motor and a drum brake, wherein the wheel hub motor comprises a drive rotor and a drive stator, and wherein the drum brake comprises a brake drum and a brake unit received in the brake drum, and wherein the drive brake unit comprises a base plate to which the drive stator is attached, the brake unit being arranged on a first side of the base plate, and wherein the brake unit is configured for a mechanical connection with a vehicle interface of a vehicle arranged on a second side of the base plate opposite the first side. The invention further relates to a vehicle comprising at least one drive brake unit of the aforementioned type.

[0002] Such a drum brake is known, for example, from WO 2013 004 410 A1.

[0003] Another drive brake unit with a drum brake is known, for example, from EP 27 41 933 B1. An actuator mechanism and the brake shoes of the drum brake are attached to an axially outer base of a pot-shaped stator housing. The brake drum is integrally formed with the drive rotor.

[0004] Further wheel-integrated electric motors with integrated drum brakes are known from DE 11 2010 002 771 T5 and US 2020 044 514 A1.

[0005] When integrating drum brakes and wheel hub motors into drive brake units, the question arises as to what the spreading mechanism and the brake shoes should be attached to, since the steel base plate usually used for drum brakes alone also significantly increases the weight of the drive brake unit and thus the unsprung masses.

[0006] At the same time, wheel hub motors are more sensitive than drum brakes in terms of shielding from the environment.

[0007] The invention is therefore based on the objective of providing a drive brake unit of the type mentioned above with improved integration of wheel hub motor and drum brake.

[0008] According to the invention, this problem is solved by a drive brake unit of the type mentioned above, which is characterized in that at least one sealing element is arranged between at least one component of the drum brake and an opening extending through the base plate to seal the first side against the second side.

[0009] This design allows the base plate supporting the drive stator to also serve as the base plate for the drum brake unit. The drum brake therefore does not include a separate brake anchor plate (as is usually the case with drum brakes without a wheel hub motor); this function is fulfilled by the base plate. The base plate, as part of the wheel hub motor housing, is sealed by at least one sealing element between at least one component of the drum brake and an opening through the base plate. The wheel hub motor is even more susceptible to the ingress of fluids and dirt than a drum brake alone and therefore requires special protection against fluid ingress.The sealing element also allows for sealing against brake dust escaping from the drive brake unit, thereby significantly reducing the fine dust emissions of the connected vehicle.

[0010] The wheel hub motor (or wheel-integrated electric motor) can be arranged axially overlapping with the drum brake in the drive brake unit. The drum brake according to the invention is ideally suited for integration into such a drive brake unit without unnecessarily increasing the overall weight of the drive brake unit by adding a separate brake anchor plate.

[0011] At the same time, a significant reduction in service life due to the ingress of liquids or dirt can be avoided. The electric motor can comprise a drive stator and a drive rotor.

[0012] The drive stator is the part of the stator that actively contributes to the drive, for example, a winding section and its associated winding support. Similarly, the drive rotor is the part of the rotor that actively contributes to the drive and, for example, carries permanent magnets, such as an inner rotor and / or an outer rotor.

[0013] In this document, "axial" or "axial direction" refers to the direction parallel to the axis of rotation of the vehicle wheel, the drive brake unit, or the brake drum during operation, while "radial" or "radial direction" refers to the direction(s) perpendicular to said axis of rotation. In this document, the term "drive brake unit" refers to a combination of a friction brake with a wheel-integrated electric motor (or wheel hub motor).

[0014] Preferred embodiments and further developments of the invention can be found in the respective dependent claims.

[0015] The term "brake unit" refers, for example, to an arrangement consisting of one or more of the following elements: a spreading device (hydraulic wheel cylinder or electromechanically driven spreading device), at least one brake shoe (in particular two brake shoes) that can be moved by the spreading device against the brake drum, a return device for returning the brake shoes to a neutral position, an adjusting device for compensating for brake lining wear, and a parking brake lever for moving the brake shoes by means of an actuating device of a parking brake attached to the parking brake lever. According to the definition in the present application, the following are specifically not to be part of the brake unit: the brake drum, a parking brake actuator, an electromechanical service brake actuator, and other elements of the drum brake arranged on the second side of the base plate.For the purposes of this application, a drum brake is understood to mean a brake unit and a brake drum. Optional elements of the drum brake may include, for example: a parking brake actuator, a mounting frame (e.g., for the parking brake actuator), and an electromechanical service brake actuator.

[0016] In one embodiment, the drum brake comprises a hydraulically actuated wheel cylinder arranged on the first side of the base plate for displacing brake shoes of the brake unit against the brake drum, wherein at least one sealing element is arranged between the wheel cylinder and the base plate, such that at least one hydraulic brake line is guided from the second side through a brake line opening in the base plate to the first side in a sealed manner. Two hydraulic brake lines can also be guided and sealed through the same sealing element. Alternatively, a hydraulic line and a degassing valve can be sealed by the same sealing element.

[0017] It is preferred that the sealing element between the wheel cylinder and the base plate is guided around at least one hydraulic brake line and at least one wheel cylinder mounting element to seal both. This simplifies the assembly of the drive brake unit. The sealing element may have a common opening through which the at least one wheel cylinder mounting element and the at least one hydraulic brake line are guided.

[0018] Preferably, the wheel cylinder has a (e.g., rectangular) connection base that rests axially against the sealing element. The sealing element can cover the surface of the connection base except for an opening for the hydraulic brake line and / or a degassing valve and / or the at least one wheel cylinder mounting element.

[0019] Preferably, the drum brake comprises an electromechanically actuated actuator arranged on the second side of the base plate, wherein an actuating element extends from the actuator from the second side through an actuating element opening in the base plate to the first side, wherein the actuating element is in functional actuating connection with the brake unit, and wherein the actuating element opening is sealed by at least one sealing element. The electromechanically actuated actuator can be the sole actuator of the brake unit (e.g., in an electromechanical service brake) or merely an additional electromechanical parking brake actuator provided in addition to a service brake actuator (hydraulic or electromechanical).

[0020] In one embodiment, the electromechanically actuated actuator is an electromechanical service brake actuator, in particular comprising a parking brake integrated into a gearbox of the service brake actuator. Control electronics for the electromechanical service brake actuator can be arranged on or at the other side of the base plate. A service brake actuator is understood to be an actuator that not only provides parking brake functionality but is also designed to provide an adjustable and variable braking force during operation by actuating the brake unit.

[0021] Preferably, the actuating means is a gearbox connected to a spreading unit of the brake unit on the first side of the base plate, which extends at least partially through the actuating means opening. The spreading unit can be connected at both ends to brake shoes of the brake unit, so that the spreading unit can move the brake shoes against the brake drum to generate a braking torque.

[0022] In one embodiment, the electromechanically actuated actuator is an electromechanical parking brake actuator. The electromechanical parking brake actuator can linearly displace an associated actuating element that is mechanically connected to the brake unit in order to engage one or more brake shoes with the brake drum, in particular to provide a parking brake function.

[0023] Preferably, the drum brake comprises a mounting frame, wherein the electromechanically actuated actuator is attached to the second side of the base plate by means of the mounting frame, wherein at least one sealing element is arranged between the mounting frame and the base plate.

[0024] Preferably, the drum brake comprises a mounting frame, wherein the electromechanically actuated actuator is attached to the second side of the base plate by means of the mounting frame, and wherein at least one sealing element is arranged between the mounting frame and the electromechanically actuated actuator. The mounting frame can, for example, extend the actuating element opening on the second side of the base plate to achieve stable guidance of an actuating element. A sealing element can then be arranged at an axial end of the actuating element opening on the second side of the base plate to seal the actuating element opening between the mounting frame and the electromechanically actuated actuator.

[0025] In a preferred embodiment, - at least one sealing element, an O-ring, and / or - at least one sealing element, an overmolded O-ring, and / or - at least one sealing element, a flat sealing element (in particular a sealing membrane) with an opening for the passage of the element to be sealed.

[0026] It is preferred that the drum brake includes a mounting frame, wherein the parking brake actuator is attached to the second side of the base plate by means of the mounting frame such that the actuating element runs at an angle of 10° to 80°, preferably 30° to 60°, and particularly preferably 40° to 50°, relative to a plane parallel to the base plate. Particularly when the actuating element is a cable or similar traction element, this avoids large-angle deflections (e.g., by 90°), which reduces wear and stress on the actuating element. At the same time, axial installation space can be saved if the parking brake actuator is arranged at an angle (e.g., substantially diagonally at -45°) to the axis of rotation of the drive brake unit and thus projects less far towards the vehicle beyond the base plate.

[0027] Preferably, a guide element adjacent to the actuating element opening is arranged on the first side of the base plate. This guide element is configured to redirect the actuating element between the actuating element opening and the brake unit, such that the actuating element runs between the guide element and a connection to the brake unit at an angle of 0°–30°, preferably 0°–20°, and particularly preferably 0°–10°, relative to a plane parallel to the base plate. This allows the actuating element to act on the brake unit (especially on the parking brake lever) with an optimal force direction. The guide element can additionally cover a sealing element on the first side of the base plate to further improve the seal. Furthermore, the guide element can also provide a rounded opening edge for the actuating element opening to reduce wear on the actuating element.

[0028] Preferably, the actuating means comprises a cable connected to the brake unit and guided through the actuating means opening. The cable can be made of a variety of metal wires.

[0029] Preferably, a winding section of the drive stator of the wheel hub motor is also attached to the base plate. The base plate then serves both as a guide for the brake shoes and as a support for the winding section. The winding section can extend from the base plate essentially in the axial direction. The winding section is preferably arranged on the same side of the base plate as the brake drum and / or the brake unit. The winding section can be energized with an alternating electric current to generate a magnetic field that interacts with permanent magnets of the rotor to produce a torque between the drive rotor and the drive stator.

[0030] It is preferred that the wheel hub motor is a double-rotor radial flux motor in which the drive stator comprises a winding section arranged radially between an outer rotor with permanent magnets and an inner rotor with permanent magnets. The wheel hub motor may include a drive rotor that is substantially cup-shaped, with the outer rotor forming the radial outer wall of the drive rotor and the inner rotor arranged as a flange on a cup bottom of the drive rotor. The drive rotor may be attached, together with the brake drum, to a rotatable inner section of the wheel bearing.

[0031] In one embodiment, the brake unit is arranged radially inside and axially essentially at the same height as a winding section and / or an outer rotor with permanent magnets and / or an inner rotor with permanent magnets. This allows for a particularly space-efficient arrangement of the brake unit, which is especially well-suited for combination with radially large twin-rotor radial flux motors. "Axially essentially at the same height" means that the brake unit overlaps with the respective other component for at least 50% of its axial length.

[0032] Preferably, a wheel bearing is arranged radially inside the drive stator and axially overlapping with the drive stator, with a stationary outer ring (outer bearing) of the wheel bearing being connected to the base plate. A rotatable inner section of the wheel bearing can be connected to the brake drum and / or the drive rotor.

[0033] The problem according to the invention is also solved by a vehicle comprising at least one drive brake unit according to one of the preceding embodiments.

[0034] Further details of the invention will become apparent from the description of the illustrated embodiments and the attached claims.

[0035] The drawings show: Fig. 1 an isometric partially exploded view of an embodiment of a drive brake unit according to the invention showing the detail of the connection of the wheel cylinder to the base plate, Fig. 2 an isometric partially exploded view of a further embodiment of a drive brake unit according to the invention showing the detail of the connection of the parking brake actuator to the base plate, Fig. 3 an isometric partially exploded view of the mounting frame and base plate accordingly Fig. 2, Fig. 4 a sectional view through connected parking brake actuator, mounting frame and base plate accordingly Fig. 2, Fig. 5 an isometric partially exploded view of a further embodiment of a drive brake unit according to the invention with the detail of a guide element on the first side of the base plate for an actuating element, Fig. 6. A view of a guide element in the opposite direction. Fig. 5 slightly modified embodiment, seen here along the axial direction.

[0036] 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.

[0037] Fig. Figures 1 to 6 show embodiments and components of drive brake units 1 according to the invention, comprising a wheel-integrated electric motor and a drum brake arranged axially overlapping with the electric motor. For the sake of clarity, components of the drive brake unit 1 that are not essential for explaining the invention are not shown in the figures.

[0038] As in Fig. As can be seen in Figure 1, the drum brake includes a spreading mechanism, here in the form of a wheel cylinder 2. The drive brake unit 1 comprises a base plate 3, which both supports the drive stator with a winding section and serves as the base of a brake unit 4 of the drum brake. The brake unit 4 is arranged on a first side 5 of the base plate 3. A central axis of rotation A of the drive brake unit 1, or in particular of the drive rotor and the brake drum, is located in Fig. 1 and Fig. 5 indicated.

[0039] At least one sealing element is arranged between at least one component of the drum brake and an opening extending through the base plate 3 to seal the first side 5 against the second side 6 (see better Fig. 2).

[0040] Accordingly Fig. 1 is a hydraulically actuated wheel cylinder 2 arranged on the first side 5 of the base plate 3 for moving brake shoes of the brake unit 4 against the brake drum. A sealing element 7 (sealing diaphragm or flat sealing element) is arranged between the wheel cylinder 2 and the base plate 3. This allows a hydraulic brake line to be guided, or be guided, from the second side 6 through a brake line opening 9 in the base plate 3 to a hydraulic connection 8 in a sealed manner. A degassing valve 10 is also provided here. The sealing element 7 between the wheel cylinder 2 and the base plate 3 is guided around the hydraulic connection 8, as well as around two wheel cylinder mounting elements and the degassing valve 10, in order to seal all of these elements. The wheel cylinder mounting elements are not shown, but two mounting element openings 9A next to the brake line opening 9 are.

[0041] Fig. Figure 2 shows the integration of an electromechanical parking brake actuator 11 into the base plate 3. The electromechanical parking brake actuator 11 can linearly displace a connected actuating element 12 (here comprising a cable). The actuating element 12 is mechanically connected to the brake unit 4 (in particular to a parking brake lever) to engage one or more brake shoes with the brake drum, especially to provide a parking brake function.

[0042] The drum brake further comprises a mounting frame 13, wherein the parking brake actuator 11 is attached to the second side 6 of the base plate 3 by means of the mounting frame 13. The mounting frame 13 extends an actuating element opening 14 on the second side 6 of the base plate 3 to achieve stable guidance of an actuating element 12. A sealing element 15 (O-ring or overmolded O-ring) is arranged at an axial end of the actuating element opening 14 to seal the actuating element opening 14 between the mounting frame 13 and the parking brake actuator 11. The mounting frame 13 is shown partially cut away here for better visibility of the actuating element opening 14, and the actuating element 12 is shown guided through the remote wall of the actuating element opening 14 only for better visibility.The end of the actuating means 12 which is functionally connected to the brake unit 4 is located on the first side 5 of the base plate 3 in the assembled state.

[0043] The parking brake actuator 11 is attached to the second side 6 of the base plate 3 by means of the mounting frame 13 such that the actuating element 12 runs at an angle of preferably 40° to 50° relative to a plane parallel to the base plate 3. Particularly when the actuating element 12 is a cable or similar tension element, this avoids large-angled (e.g., 90°) detours, which reduces wear and stress on the actuating element 12. At the same time, axial installation space can be saved if the parking brake actuator 11 is arranged at an angle (e.g., substantially diagonally at ~45°) to the axis of rotation of the drive brake unit 1 and thus projects less far towards the vehicle beyond the base plate 3.

[0044] As in Fig. 3 and Fig. As shown in Figure 4, a (further) sealing element 16 (O-ring) is arranged between the mounting frame 13 and the base plate 3.

[0045] As in Fig. 5 and Fig. Figure 6 shows that on the first side 5 of the base plate 3, a guide element 17 is arranged adjacent to the actuating means opening 14, which is configured to deflect the actuating means 12 between the actuating means opening 14 and the brake unit 4. As a result, the actuating means 12 runs between the guide element 17 and a connection to the brake unit 4 at an angle of preferably 0° - 10°, relative to a plane parallel to the base plate.

[0046] As in Fig. As shown in Figure 5, the guide element 17 can additionally cover the sealing element 16 on the first side 5 of the base plate 3 by forming a loop 17A which corresponds to the opening contour of the actuating element opening 14 on the first side 5, in order to further improve the seal. For this purpose, the guide element 17 can be attached to the base plate 3 as a separate component, in particular by means of a fastening element 18 (here a screw) using a sealing element 19 (O-ring).

[0047] According to Fig. 6 the guide element 17 is formed in one piece with the base plate 3.

[0048] In both embodiments of the Fig. 5 and Fig. 6 The guide element includes a guide notch 20 for guiding the actuating means 12, especially if it includes a cable. Reference symbol list: 1 drive brake unit 2 wheel cylinders 3 Base plate 4 brake unit 5 first page 6 second page 7 Sealing element 8 hydraulic connection 9 Brake line opening 9A Fastening element opening 10 Degassing valve 11 Parking brake actuator 12 Actuators 13 mounting frames 14 Actuator opening 15 Sealing element 16 Sealing element 17 Guide element 17A loop 18 Fasteners 19 Sealing element 20 guide notch A axis of rotation QUOTES INCLUDED IN THE DESCRIPTION

[0000] 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

[0000] WO 2013 004 410 A1

[0002] EP 27 41 933 B1

[0003] DE 11 2010 002 771 T5

[0004] US 2020 044 514 A1

[0004]

Claims

[1] Drive brake unit (1) comprising a wheel hub motor and a drum brake, wherein the wheel hub motor comprises a drive rotor and a drive stator, and wherein the drum brake comprises a brake drum and a brake unit (4) received in the brake drum, and wherein the drive brake unit (1) comprises a base plate (3) to which the drive stator is attached, wherein the brake unit (4) is arranged on a first side (5) of the base plate (3), wherein the brake unit (4) is configured to form a mechanical connection with a second side (6) of the base plate (3) opposite the first side (5), characterized by, that at least one sealing element (7, 15, 16) is arranged between at least one component of the drum brake and an opening (9, 14) passing through the base plate (3) to seal the first side (5) against the second side (6). [2] Drive brake unit (1) according to claim 1, characterized by , that the drum brake comprises a hydraulically actuated wheel cylinder (2) arranged on the first side (5) on the base plate (3) for displacing brake shoes of the brake unit (4) against the brake drum, wherein at least one sealing element (7) is arranged between the wheel cylinder (2) and the base plate (3), such that at least one hydraulic brake line is guided from the second side (6) through a brake line opening (9) in the base plate (3) to the first side (5) in a sealed manner. [3] Drive brake unit (1) according to claim 2, characterized by, that the sealing element (7) between the wheel cylinder (2) and the base plate (3) is guided around at least one hydraulic brake line and at least one wheel cylinder mounting element to seal both. [4] Drive brake unit (1) according to one of the preceding claims, characterized by , that the drum brake comprises an electromechanically actuated actuator (11) arranged on the second side (6) of the base plate (3), wherein an actuating means (12) extends from the actuator (11) from the second side (6) through an actuating means opening (14) in the base plate (3) to the first side (5), wherein the actuating means (12) is in functional actuating connection with the brake unit (4), and wherein the actuating means opening (14) is sealed by at least one sealing element (15, 16). [5] Drive brake unit (1) according to claim 4, characterized by, that the electromechanically actuated actuator is an electromechanical service brake actuator, in particular comprising a parking brake integrated into a gearbox of the service brake actuator. [6] Drive brake unit (1) according to claim 5, characterized by , that the actuating means (12) is a transmission connected to a spreading unit of the brake unit (4) on the first side (5) of the base plate (3), which extends at least partially through the actuating means opening (14). [7] Drive brake unit (1) according to claim 4, characterized by , that the electromechanically actuated actuator is an electromechanical parking brake actuator (11). [8] Drive brake unit (1) according to one of claims 4 to 7, characterized by, that the drum brake comprises a mounting frame (13), wherein the electromechanically actuated actuator (11) is attached to the second side (6) of the base plate (3) by means of the mounting frame (13), wherein at least one sealing element (16) is arranged between the mounting frame (13) and the base plate (3). [9] Drive brake unit (1) according to claim 7 or 8, characterized by , that the drum brake comprises a mounting frame (13), wherein the electromechanically actuated actuator (11) is attached to the second side (6) of the base plate (3) by means of the mounting frame (13), wherein at least one sealing element (15) is arranged between the mounting frame (13) and the electromechanically actuated actuator (11). [10] Drive brake unit (1) according to one of the preceding claims, characterized by , that - at least one sealing element (15, 16, 19) is an O-ring, and / or - at least one sealing element (15) is an overmolded O-ring, and / or - at least one sealing element (7) is a flat sealing element with an opening for the passage of the element to be sealed. [11] Drive brake unit (1) according to one of claims 7 to 10, characterized by , that the drum brake comprises a mounting frame (13), wherein the parking brake actuator (11) is attached to the second side (6) of the base plate (3) by means of the mounting frame (13) such that the actuating means (12) runs at an angle of 10° - 80°, preferably 30° - 60° and particularly preferably 40° - 50°, relative to a plane parallel to the base plate (3). [12] Drive brake unit (1) according to one of claims 7 to 11, characterized by, that on the first side (5) of the base plate (3) a guide element (17) adjacent to the actuating means opening (14) is arranged, which is configured to deflect the actuating means (12) between the actuating means opening (14) and the brake unit (4), so that the actuating means (12) runs between the guide element (17) and a connection to the brake unit (4) at an angle of 0° - 30°, preferably 0° - 20° and particularly preferably 0° - 10°, relative to a plane parallel to the base plate (3). [13] Drive brake unit (1) according to any one of claims 7 to 12, characterized by , that the actuating means (12) comprises a cable connected to the brake unit (4) which is guided through the actuating means opening (14). [14] Drive brake unit (1) according to one of the preceding claims, characterized by, that the wheel hub motor is a double-rotor radial flux motor in which the drive stator comprises a winding section arranged radially between an outer rotor with permanent magnets and an inner rotor with permanent magnets. [15] Drive brake unit (1) according to one of the preceding claims, characterized by , that the brake unit (4) is arranged radially inside and axially at substantially the same level as the drive stator and / or an outer rotor with permanent magnets and / or an inner rotor with permanent magnets. [16] Drive brake unit (1) according to one of the preceding claims, characterized by , that a wheel bearing is arranged radially inside the drive stator and axially overlapping with the drive stator, wherein a stationary outer ring of the wheel bearing is connected to the base plate (3). [17] Vehicle comprising at least one drive brake unit (1) according to any one of the preceding claims.

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