Electromechanical drum brake

Abstract

The invention relates to an electromechanical drum brake. An electromechanical drum brake (10) has a brake anchor plate (12) which is mounted on a vehicle, a brake drum (14) which is mounted on a wheel, an expansion mechanism (16) which is fastened to the brake anchor plate (12) and is designed to push brake leading shoes (20) and brake trailing shoes (22) of the drum brake (10) away from one another in opposite directions along a working axis (W) and against the brake drum (14), and a support block (18) which is fastened to the brake anchor plate (12), projects into the brake drum (14) and forms a first support bearing for the brake leading shoes (20) and a second support bearing for the brake trailing shoes (22). In this case, the first support bearing and / or the second support bearing is formed in each case by a strain-sensitive sensor unit (48, 50).

Description

Technical Field

[0001] This invention relates to an electromechanical drum brake comprising: a brake anchor plate mounted on a vehicle; a brake drum mounted on a wheel; an expansion mechanism fastened to the brake anchor plate and designed to push the leading brake shoe and the trailing brake shoe of the electromechanical drum brake away from each other and against the brake drum in opposite directions along the working axis; and a support block fastened to the brake anchor plate, protruding into the brake drum, and forming a first support bearing for the leading brake shoe and a second support bearing for the trailing brake shoe. Background Technology

[0002] This type of electromechanical drum brake is known.

[0003] Drum brakes are frequently used as service brakes in motor vehicles. They also provide parking brake functionality. Compared to hydraulically actuated drum brakes, electromechanical drum brakes have the advantage that they operate independently of the hydraulic braking system and can be directly triggered by the vehicle's electronic systems. Summary of the Invention

[0004] The purpose of this invention is to provide an electromechanical drum brake that ensures a defined effective braking torque.

[0005] This objective is achieved by an electromechanical drum brake comprising: a brake anchor plate mounted on a vehicle; a brake drum mounted on a wheel; an expansion mechanism fastened to the brake anchor plate and designed to push the leading and trailing brake shoes of the electromechanical drum brake away from each other and against the brake drum in opposite directions along the working axis; and a support block fastened to the brake anchor plate, protruding into the brake drum, and forming a first support bearing for the leading brake shoe and a second support bearing for the trailing brake shoe. In each case, the first and / or second support bearings are formed by a strain-sensitive sensor unit.

[0006] In the context of this invention, a brake leading shoe is a brake shoe that forms a brake leading shoe when the vehicle is traveling in the main direction or when it is traveling forward.

[0007] The supporting force exerted by the brake leading shoe or brake trailing shoe on the corresponding support bearing is detected by a designated strain-sensitive sensor. This supporting force can be used to calculate the effective braking torque on the brake drum under dynamic and static conditions, and based on this data, it can be ensured that the defined braking torque is effective. In this way, vehicle stability can be improved, for example, by generating nearly identical braking torque on both sides of the vehicle axle. It can also be detected whether the braking torque has been appropriately reduced after braking, or whether there is any unwanted residual braking torque.

[0008] According to one aspect, a drum brake is an electromechanically actuated unidirectional drum brake. The advantage of a unidirectional drum brake over a bidirectional drum brake or a servo drum brake is that it does not respond sensitively to changes in the friction value of the brake pads (e.g., due to temperature changes), and therefore does not cause such large fluctuations in braking torque.

[0009] In one embodiment, the sensor unit has an expansion membrane that forms a corresponding support bearing. The supporting force exerted by the associated brake shoe on the corresponding support bearing causes elastic deformation, and thus causes a specific surface of the expansion membrane to expand, which is detected by a strain-sensitive sensor.

[0010] In this configuration, the expansion membrane can be disc-shaped and centered within the recess of the support block via its cylindrical centering portion. Furthermore, it can abut against the end face of the support block with a large area of ​​annular contact surface. This design allows for exceptionally high-quality detection of the support force.

[0011] Furthermore, it can be specified that the cylindrical axes of the centering portion and the recess extend parallel to the working axis of the expansion mechanism, and that the contact surface of the expansion membrane and the end face of the support block extend in a plane perpendicular to the working axis of the expansion mechanism. This further improves the quality of detecting the support force.

[0012] Alternatively, the expansion membrane can be formed as rotationally symmetrical with respect to the cylindrical axis of the central portion. The advantage of this symmetrical design is that the surface of the expansion membrane deforms elastically accordingly symmetrically, and therefore, the expansion of the expansion membrane can be detected with particularly high precision.

[0013] In another embodiment, the sensor unit has multiple strain-sensitive sensors that are part of a Wheatstone measuring bridge. In this way, the expansion of the expansion membrane can be determined particularly effectively, and thus the supporting force acting on the expansion membrane can be determined.

[0014] In this configuration, the strain-sensitive sensor can be fastened or attached to the inside of the expansion diaphragm, away from the assigned brake shoe. Therefore, the strain-sensitive sensor is positioned such that, on the one hand, it is protected, and on the other hand, the surface expansion of the expansion diaphragm can be effectively detected from this location.

[0015] Furthermore, strain-sensitive sensors can be designed as foil strain gauges using thin-film technology, or as semiconductor strain gauges based on the piezoresistive effect, thus making them particularly efficient and compact.

[0016] In one embodiment, the sensor unit has a printed circuit board that is secured to the expansion film via an insulating disc. In this way, the printed circuit board is mounted on the expansion film in a heat-protected manner.

[0017] According to one aspect, the expansion membrane is fastened to the base of the support block by means of a fastening sleeve in a form-fitting manner, thus effectively fastening it to the base of the support block.

[0018] In another embodiment, the first support bearing is formed by a first strain-sensitive sensor unit, and the second support bearing is formed by a second strain-sensitive sensor unit. The expansion membrane, consisting of these two support bearings, is mounted on opposite sides of the substrate, and the electronic components are housed within the substrate. In this way, the support block is particularly compact and robust.

[0019] Here, the tension spring connecting the two brake shoes can extend radially outward from the support bearing. The brake shoes are pulled towards the support block by the tension spring, which results in always ensuring the brake shoes are in the correct position and reliably avoiding residual braking torque.

[0020] Furthermore, it can be specified that the support bearing is positioned at the end opposite to the end associated with the brake shoe and the expansion mechanism. This thus makes efficient use of existing installation space.

[0021] Furthermore, the support bearing can be located between the ends of the brake shoes arranged opposite to the end associated with the expansion mechanism, and between the end faces of the brake shoes that contact the support bearing. In this way, the drum brake is particularly compact and effective. Attached Figure Description

[0022] Further advantages and features will become apparent from the following description and accompanying drawings, in which: Figure 1 A drum brake with a support block according to the present invention is shown in a perspective view; Figure 2 The sectional view shows the source Figure 1 Support blocks; Figure 3The exploded diagram shows the data from... Figure 1 Support blocks; Figure 4 The exploded diagram shows the data from... Figure 1 The strain-sensitive sensor unit of the support block; and Figure 5 The Wheatstone bridge is shown in the schematic diagram. Detailed Implementation

[0023] The following detailed description, taken in conjunction with the accompanying drawings (in which like reference numerals refer to like elements), is intended to describe different embodiments of the disclosed subject matter, and not to represent only those embodiments. Each embodiment described in this disclosure is merely illustrative or for purposes of explanation and should not be construed as preferred or advantageous over other embodiments.

[0024] All features disclosed below with reference to exemplary embodiments and / or drawings may be combined individually or in any sub-combination with features of various aspects of this disclosure (including features of preferred embodiments), provided that the resulting combination of features is meaningful to those skilled in the art.

[0025] Figure 1 An electromechanical drum brake 10 for a motor vehicle is shown, the electromechanical drum brake 10 having a brake anchor plate 12 mounted on the vehicle and a brake drum 14 mounted on the wheel.

[0026] The drum brake 10 is, for example, an electromechanically actuated one-way drum brake.

[0027] Brake anchor plate 12 is fixedly mounted on a motor vehicle in a manner that prevents rotation, for example, on the anti-torsion axle of a motor vehicle.

[0028] On the other hand, the brake drum 14 is fixedly connected to the wheel of the motor vehicle, for example, via the wheel hub, and is therefore rotatably mounted relative to the brake anchor plate 12 in the circumferential direction U and opposite to the circumferential direction U.

[0029] The drum brake 10 also has an expansion mechanism 16 and a support block 18, both of which are fastened to the brake anchor plate 12 and protrude into the brake drum 14. The drum brake 10 also has a brake leading shoe 20 and a brake trailing shoe 22, both of which have friction pads 24 arranged to interact with a friction surface 26 on the inner side of the brake drum 14 (see...). Figure 2 )relatively.

[0030] The brake leading shoe 20 and the brake trailing shoe 22 are designed as, for example, sliding shoes, so there are no fixed bearings or fixed pivot points.

[0031] In this embodiment, the brake leading shoe 20 and the brake trailing shoe 22 are designed similarly, for example, to be mirror-symmetrical to each other.

[0032] In order to actuate the expansion mechanism 16, the drum brake 10 has an actuator 27, which is arranged behind the brake anchor plate 12, i.e., opposite to the brake drum 14.

[0033] The expansion mechanism 16 is designed to guide the brake lead shoe 20 and the brake slave shoe 22 along the working axis W (see...). Figure 1 They push each other away in opposite directions and press against each other on the friction surface 26.

[0034] For this purpose, the expansion mechanism 16 is arranged between the two first ends 28, 29 of the brake leading shoe 20 and the brake trailing shoe 22, and the expansion mechanism 16 acts on these two first ends.

[0035] In addition, the brake lead shoe 20 and the brake follow shoe 22 abut against the support block 18 via the second ends 30 and 31, and the second ends 30 and 31 are arranged opposite to the first ends 28 and 29 in the circumferential direction U.

[0036] The brake leading shoe 20 passes through the end face 32 of the second end 30 (see...). Figure 2 The brake shoe 22 abuts against the first support bearing 34 of the support block 18, while the brake shoe 22 abuts against the second support bearing 38 of the support block 18 through the end face 36 of the second end 31. The second support bearing 38 is arranged opposite to the first support bearing 34.

[0037] The brake leading shoe 20 and the brake trailing shoe 22 are pulled toward the support block 18 by a first tension spring 40, which is arranged, for example, radially on the outside of the support block 18 and connects the second ends 30, 31 to each other.

[0038] At opposite ends, the brake leading shoe 20 and the brake trailing shoe 22 pass through the pressure sleeve 42 (see...). Figure 1 It is kept at a limited distance and pulled toward the expansion mechanism 16 by the second tension spring 44.

[0039] For example, an automatic friction liner wear adjuster is integrated into the pressure sleeve 42, which maintains a nearly constant clearance between the brake leading shoe 20 and the brake trailing shoe 22 and the brake drum 14 under wear conditions. The distance between the brake leading shoe 20 and the brake trailing shoe 22 is adjusted according to wear using the adjusting screw 46.

[0040] In order to generate braking torque on the wheel distributed by the drum brake 10, the friction pads 24 of the two opposing brake leading shoes 20 and brake trailing shoes 22 are expanded by the expansion mechanism 16 with an expansion force F. SThe brake drum 14 is pressed against its inner friction surface 26. In each case, the gap between the brake leading shoe 20 and the brake trailing shoe 22 and the brake drum 14 in the unacted position is overcome. The required expansion force and the required actuation stroke are generated by the bidirectional expansion mechanism 16.

[0041] The expansion force F applied to the two leading brake shoes 20 and the trailing brake shoes 22 S They are basically the same in size, but act in opposite directions for each of the leading brake shoe 20 and the trailing brake shoe 22.

[0042] The brake leading shoe 20 and the brake trailing shoe 22 are supported on a fixed support block 18 at their second ends 30 and 31, and in each case, under the actuation of the expansion mechanism 16, opposing support forces F1 and F2 are applied to the support block 18.

[0043] In this way, a frictional torque is generated on the brake drum 14, through which the rotational motion of the brake drum 14 is delayed or stopped as appropriate.

[0044] Because the brake drum 14 is connected to the tire of the wheel via the rim and the tire is in contact with the road surface, a condition-related braking torque is generated, through which the motor vehicle is decelerated or held in an inactive position.

[0045] If the vehicle is stationary in the horizontal direction, it is impossible to distinguish between the leading brake shoe 20 and the trailing brake shoe 22, because in this case the brake drum 14 is not set to rotate, and there is no downhill force. In this case, the magnitudes of the support forces F1 and F2 are the same. If the vehicle is dynamically braked or statically parked on a slope, the support force F1 applied by the leading brake shoe 20 is many times greater than the support force F2 applied by the trailing brake shoe 22. This fact is... Figure 2 The arrows, of different lengths, indicate the supporting forces F1 and F2.

[0046] In order to detect the supporting forces F1 and F2, the first support bearing 34 is formed by a first strain-sensitive sensor unit 48, while the second support bearing 38 is formed by a second strain-sensitive sensor unit 50.

[0047] In an alternative embodiment, the support block 18 may include only one of the two sensor units 48, 50, so that, accordingly, only the support force F1 of the braking lead shoe 20 or the support force F2 of the braking follower shoe 22 can be detected.

[0048] In this embodiment, the second strain-sensitive sensor unit 50 is designed in the same manner as the first strain-sensitive sensor unit 48. Therefore, referring to... Figures 2 to 5The structure of sensor units 48, 50 is described below with reference to an example of a first strain-sensitive sensor unit 48. For clarity, in Figure 2 In the figure, some features of the first strain-sensitive sensor unit 48 are marked with reference numerals at corresponding positions in the second strain-sensitive sensor unit 50.

[0049] Sensor unit 48 (see Figure 2 It has an expansion film 52 with a central contact area 54, which forms a first support bearing 34 for braking leading shoe 20.

[0050] The expansion membrane 52 is rotationally symmetrical about the axis of symmetry S and is disk-shaped.

[0051] In this embodiment, the expansion membrane 52 is formed of an elastic material, such as high-strength steel.

[0052] Opposite to the contact area 54, the expansion membrane 52 has a cylindrical centering portion 56, which is received in a stepped cylindrical recess 58 in the base 60 of the support block 18.

[0053] The recess 58 is designed to complement the centering portion 56, such that the cylindrical axis Y of the centering portion 56 coincides with the cylindrical axis Z of the recess 58, and thus the centering portion 56 is centered in the recess 58.

[0054] The cylindrical axis Y of the central portion 56 also coincides with the axis of symmetry S of the expansion membrane 52.

[0055] An annular seal 62 is arranged between the centering portion 56 and the substrate 60, which seals the chamber 64 inside the substrate 60.

[0056] The expansion membrane 52 also has an annular contact surface 66 arranged radially outward, through which the expansion membrane 52 abuts against the annular end face 68 of the substrate 60 in a large area in the axial direction, and is supported on the substrate 60 in the direction of the supporting force F1.

[0057] In view of this, the cylindrical axes Y and Z of the central portion 56 and the recess 58 are parallel to the working axis W of the expansion mechanism 16 (see...). Figure 1 )extend.

[0058] Furthermore, the contact surface 66 of the expansion film 52 and the end face 68 of the substrate 60 are in plane E (see Figure 2 Extending from the cylinder, plane E is perpendicular to the cylinder axis Y, and Z extends.

[0059] The expansion membrane 52 is fastened to the substrate 60 by the fastening sleeve 70 in a form-fitting manner.

[0060] The fastening sleeve 70 is centered on the base 60 and is fixedly connected to the base 60, for example, by means of a rolled edge.

[0061] In the illustrated embodiment, the contact area 54 protrudes axially relative to the fastening sleeve 70 (see...). Figure 2 As a result, the end face 32 of the brake leading shoe 20 abuts against the contact area 54 in a manner axially spaced from the fastening sleeve 70. This ensures that the brake leading shoe 20 does not contact the fastening sleeve 70, regardless of the degree of elastic deformation of the expansion membrane 52 during operation.

[0062] To detect the supporting force F1 acting on the expansion membrane 52, the sensor unit 48 has multiple strain-sensitive sensors 72 (see Figure 4 These strain-sensitive sensors 72 are mounted on the inner side 74 of the expansion diaphragm 52 opposite to the brake leading shoe 20 and are radially mounted within the centering portion 56.

[0063] For example, sensor unit 48 has four strain-sensitive sensors 72.

[0064] In this embodiment, a strain-sensitive sensor 72 is arranged on the surface of the expansion film 52 in the transition region between the contact area 54 and the contact surface 66.

[0065] In all embodiments, the strain-sensitive sensor 72 is connected or coupled to the expansion membrane 52 in such a way that the strain deformation of the expansion membrane 52 is transmitted to and thus detected by the strain-sensitive sensor 72.

[0066] The strain-sensitive sensor 72 is connected to the printed circuit board 76 of the sensor unit 48 for signal transmission, and is a Wheatstone bridge 78 (see [link]). Figure 5 Part of ).

[0067] In one embodiment, the strain-sensitive sensor 72 is formed from a foil strain gauge (DMS) connected to form a Wheatstone half-bridge or full-bridge. The measuring grid of the foil strain gauge has strain-dependent measuring resistance. The measuring bridge 78 compensates for temperature expansion.

[0068] In an alternative embodiment, the strain-sensitive sensor 72 is fabricated using thin-film technology. In this case, a thin, strain-sensitive, conductive, tortuous metal layer, such as a nickel-chromium precision resistance alloy, is applied to the inner side 74 of the expansion membrane 52. The tortuous metal coating is segmented and oriented to form a Wheatstone half-bridge or full-bridge for temperature compensation. The tortuous metal coating has a strain-dependent measurement resistance.

[0069] In another embodiment, the strain-sensitive sensor 72 is composed of a semiconductor strain gauge based on the piezoresistive effect. The resistivity of the semiconductor changes under mechanical strain. The semiconductor strain gauge is connected to a temperature-compensated Wheatstone half-bridge or full-bridge.

[0070] A constant power supply voltage U1 is supplied to the measuring bridge 78. The strain deformation of the expansion membrane 52 causes a proportional change in the resistance 80 of the measuring bridge 78. As a result, the resistance-dependent signal voltage U2 of the measuring bridge 78 is proportional to the strain deformation of the expansion membrane 52.

[0071] Therefore, a temperature sensor can be installed on the expansion membrane 52.

[0072] The strip conductor used for measuring bridge 78 is part of printed circuit board 76.

[0073] Through the printed circuit board 76, the measuring bridge 78 is supplied with a power supply voltage U1, and the resistor-dependent analog signal voltage U2 of the measuring bridge 78 is tapped.

[0074] To protect the printed circuit board 76 from the high temperatures that the brake leading shoe 20 and brake trailing shoe 22 may experience during the operation of the drum brake 10, the printed circuit board 76 is positioned, for example, centered relative to the cylindrical axis Y via an insulating disc 82 (see...). Figure 4 Secure it to the expansion membrane 52.

[0075] In addition, a temperature sensor (not shown) may be disposed on the expansion membrane 52, which is connected to the printed circuit board 76 for signal transmission.

[0076] The printed circuit board 76 also includes an electronic evaluation chip 84 with an application-specific integrated circuit (ASIC).

[0077] According to this embodiment, an analog signal amplifier or analog-to-digital converter for measuring the resistance-dependent signal voltage of the bridge 78 is integrated in the evaluation chip 84. The analog-to-digital converter converts the resistance-dependent analog signal voltage of the bridge 78 into a digital signal voltage, for example, according to the Single-sided Half-Byte Transmission (SENT) data protocol.

[0078] Printed circuit board 76 is connected to bus 86 (see...) Figure 2 The electrical contacts are connected to the plug (not shown) via plug terminal 88.

[0079] Busbar 86 is aligned and supported by support plate 90.

[0080] The plug is located at the rear of the brake anchor plate 12 and protrudes from the base 60.

[0081] In this embodiment, the plug has electrical contacts for external contact connection of a constant power supply voltage U1 and an analog or digital signal voltage U2. The analog or digital signal voltage U2 is transmitted via the external contact connection to the control unit 92 of the drum brake 10, which is, for example, arranged in the actuator 27.

[0082] Alternatively, the printed circuit board 76 may have an electronic transmitter and antenna for wireless data transmission. In this case, the data signal from the measuring bridge 78 is wirelessly transmitted to the control unit 92, and the plug has only electrical contacts for a constant power supply voltage U1.

[0083] The expansion film 52 and the substrate 60 form a housing for electronic components (such as printed circuit boards 76 and busbars 86), which are thus arranged protectively in a chamber 64 inside the substrate 60.

[0084] During operation, when the drum brake 10 is actuated, the brake lead shoe 20 applies the supporting force F1 directly to the expansion diaphragm 52.

[0085] The supporting force F1 has the characteristics of compressive force, and is related to the expansion force F S Act in parallel.

[0086] The expansion membrane 52 is designed to elastically deform under the action of a supporting force F1, much like a coil spring. The strain deformation generated on the surface of the expansion membrane 52 is proportional to the effective supporting force F1 and is detected by a strain-sensitive sensor 72. The supporting force F1 is determined by the control unit 92 using a measuring bridge 78.

[0087] In a similar manner, the second sensor unit 50 can be used to detect the support force F2, and the brake slave shoe 22 can be used to act on the expansion membrane 52 of the second sensor unit 50.

[0088] In an embodiment where the drum brake 10 has only one of two sensor units 48, 50, the opposite sides of the base 60 are closed, for example, by a cover or wall integrally formed with the base 60.

[0089] In this manner, a drum brake 10 is provided, by means of which a defined effective braking torque can be ensured based on a determined support force F1 and / or support force F2.

Claims

1. An electromechanical drum brake (10), said electromechanical drum brake (10) having: Brake anchor plate (12) installed on the vehicle; Brake drum (14) mounted on the wheel; An expansion mechanism (16), fastened to the brake anchor plate (12), is designed to push the brake leading shoe (20) and brake trailing shoe (22) of the electromechanical drum brake (10) away from each other and against the brake drum (14) along the working axis (W) in opposite directions; and A support block (18), which is fastened to the brake anchor plate (12), protrudes into the brake drum (14), and forms a first support bearing (34) for the brake leading shoe (20) and a second support bearing (38) for the brake trailing shoe (22), wherein, The first support bearing (34) and / or the second support bearing (38) are each formed by strain-sensitive sensor units (48, 50).

2. The electromechanical drum brake (10) according to claim 1, wherein, The sensor unit (48, 50) has an expansion membrane (52) which forms a corresponding support bearing (34, 38).

3. The electromechanical drum brake (10) according to claim 2, wherein, The expansion membrane (52) is disc-shaped and is centered in the recess (58) of the support block (18) by means of a cylindrical centering portion (56), and abuts against the end face (68) of the support block (18) in a large area and axially by means of an annular contact surface (66).

4. The electromechanical drum brake (10) according to claim 3, wherein, The cylindrical axes (Y, Z) of the centering portion (56) and the recess (58) extend parallel to the working axis (W) of the expansion mechanism (16), and the annular contact surface (66) of the expansion film (52) and the end face (68) of the support block (18) extend in a plane (E) perpendicular to the working axis (W) of the expansion mechanism (16).

5. The electromechanical drum brake (10) according to claim 3 or 4, wherein, The expansion membrane (52) is formed to be rotationally symmetrical with respect to the cylindrical axis (Y) of the centering portion (56).

6. The electromechanical drum brake (10) according to any one of claims 2 to 5, wherein, The sensor unit (48, 50) has multiple strain-sensitive sensors (72), which are part of a Wheatstone measuring bridge (78).

7. The electromechanical drum brake (10) according to claim 6, wherein, The strain-sensitive sensor (72) is fastened or attached to the inside (74) of the expansion diaphragm (52) away from the assigned brake shoes (20, 22).

8. The electromechanical drum brake (10) according to claim 6 or 7, wherein, The strain-sensitive sensor (72) is designed as a metal foil strain gauge using thin-film technology, or as a semiconductor strain gauge based on the piezoresistive effect.

9. The electromechanical drum brake (10) according to any one of claims 2 to 8, wherein, The sensor unit (48, 50) has a printed circuit board (76) which is fastened to the expansion film (52) via an insulating disk (82).

10. The electromechanical drum brake (10) according to any one of claims 2 to 9, wherein, The expansion membrane (52) is fastened to the base (60) of the support block (18) in a form-fitting manner by means of a fastening sleeve (70).

11. The electromechanical drum brake (10) according to claim 10, wherein, The first support bearing (34) is formed by a first strain-sensitive sensor unit (48), and the second support bearing (38) is formed by a second strain-sensitive sensor unit (50), wherein the expansion membrane (52) formed by the two support bearings (34, 38) is mounted on opposite sides of the substrate (60), and electronic components (76, 86) are housed inside the substrate (60).

12. The electromechanical drum brake (10) according to claim 11, wherein, The tension spring (40) connecting the two brake shoes (20, 22) extends radially outward from the support bearing (34, 38).

13. The electromechanical drum brake (10) according to any one of the preceding claims, wherein, The support bearings (34, 38) are positioned at the end (30, 31) of the associated brake shoe (20, 22) opposite the end (28, 29) associated with the expansion mechanism (16).

14. The electromechanical drum brake (10) according to claim 13, wherein, The support bearings (34, 38) are located between the ends (30, 31) of the brake shoes (20, 22) that are arranged opposite to the ends (28, 29) associated with the expansion mechanism (16), and between the end faces (32, 36) of the brake shoes (20, 22) that contact the support bearings (34, 38).

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