Electromechanical frame brake

Abstract

The invention relates to an electromechanical frame brake. The electromechanical frame brake comprises a floating frame assembled by a plurality of parts; and a brake piston which can be moved axially by means of the spindle drive, is arranged on the spindle of the spindle drive and is guided in the piston receiving housing. The floating frame has a piston receiving housing, lateral struts, and an outer cross member connected to the piston receiving housing via the lateral struts. The cross member carries an outer brake pad. The floating frame is mounted in a brake carrier of the frame brake by means of an axial linear guide so as to float and be axially movable relative to the brake carrier. According to the invention, the brake carrier has a socket with a cylindrical guide surface for a piston receiving housing, in which socket the piston receiving housing is mounted in an axially displaceable manner.

Description

Technical Field

[0001] The invention relates to an electromechanical frame brake. Background Art

[0002] Electromechanical brakes with floating frames are already known.

[0003] The floating frame can be designed as a fist-type caliper, for example. However, due to the geometry of the caliper shape, a fist-type caliper brake has limited torsional stiffness. As a result, the shear forces caused by friction (friction is generated when the brake pads are applied to the brake disc rotor and causes a distortion of the components of the brake relative to the brake carrier) are only inadequately compensated. As a result, the brake pads show an uneven degree of wear. This leads to a change in the ratio of the shear forces occurring during the life of the brake pads and the brake disc rotor to the normal forces occurring (in the axial direction). The inconstancy of this force ratio prevents or at least adversely affects the provision of a constant release gap (the distance between the brake pads and the brake disc rotor, also referred to as the brake application path) during the life of the brake pads and the brake disc rotor.

[0004] As an alternative to the fist-caliper brake, the electromechanical brake can also be implemented as a frame brake. The frame brake includes an axially formed linear guide that is able to at least partially absorb and compensate the shear forces that occur. As a result, it can be ensured that the force ratio of the shear forces that occur to the normal forces that occur exhibits reduced fluctuations during the life of the brake pads and the brake disc rotor compared to the fist-caliper brake. However, these axial linear guides are typically not arranged at the center of gravity along the axial range of the frame brake. This leads to tilting forces along the axial range of the frame brake, and although these tilting forces can be smaller than the equivalent shear forces in the case of the fist-caliper brake, they still cause distortion of the components of the frame brake relative to the brake carrier. In other words, the frame brake has a limited housing stiffness along the axial longitudinal range, which is especially due to the generally higher weight caused by the linear guides. Therefore, in turn, during the life of the brake pads and the brake disc rotor, it may lead to uneven wear of the brake pads, resulting in a non-constant brake application path. Of course, the housing stiffness along the axial longitudinal range of the frame brake can be increased by appropriate dimensioning of the relevant components. However, this leads to an increase in the required installation space and the weight of the frame brake, which ultimately leads to an increase in the fuel or energy consumption of a vehicle equipped with such a frame brake.

[0005] Therefore, there is a need to eliminate or at least reduce the disadvantages of the prior art. In particular, there is a need to provide an electromechanical brake that ensures a constant brake application path over the life of the relevant components while reducing weight and installation space compared to prior approaches. Summary of the invention

[0006] According to one aspect, an electromechanical frame brake is provided. The electromechanical frame brake comprises: a floating frame assembled from a plurality of parts; and a brake piston which can be axially moved by means of a spindle drive and is mounted on the spindle of the spindle drive and is guided in a piston accommodating housing. The floating frame has the piston accommodating housing, lateral struts and an outer cross member which is connected to the piston accommodating housing via the lateral struts. The cross member carries an outer brake pad. The floating frame is mounted to float relative to a brake support of the frame brake via an axial linear guide and can be axially moved relative to the brake support. The brake support has a socket having a guide surface for the piston accommodating housing, and the piston accommodating housing is mounted in the socket in an axially movable manner.

[0007] This provides a frame brake which, in addition to the lateral struts and the axial linear guide, comprises an additional guidance by means of a socket of the brake carrier, the socket having a guide surface for a piston accommodating housing, which is movably mounted in the socket. Thus, an additional axial guiding mechanism is ensured, by means of which shear forces occurring during actuation of the frame brake can be compensated in an improved manner compared to prior methods. Furthermore, the socket of the brake carrier for the piston accommodating housing, in which the piston accommodating housing is movably mounted, can be arranged in particular closer to the center of gravity along the axial longitudinal extent of the frame brake. Thus, the occurring tilting forces caused by the weight distribution of the frame brake along the axial longitudinal extent can be reduced compared to prior methods. This provides a frame brake which has an improved housing stiffness both in terms of the occurring shear forces and in terms of the weight distribution along the axial longitudinal extent. This ensures that the force ratio of the shear forces occurring during actuation of the frame brake to the occurring normal forces is substantially constant during the life of the brake pads and the brake disc rotor. As a result, the constancy of the actual brake application path (i.e. the distance between the brake pad and the brake disc rotor) during the life of the brake pad and the brake disc rotor is improved relative to existing methods. In other words, the degree of uneven wear of the brake pad can be reduced. As a result, the actual brake application path also shows a reduced deviation from the desired brake application path during the life of the brake pad and the brake disc rotor compared to existing frame brakes. These advantages are ensured without using excessive material or (significantly) enlarging the installation space for this purpose. As a result, a solution is provided that does not cause any increase in the basic fuel or energy consumption of a vehicle equipped with such an electromechanical frame brake.

[0008] Preferably, the brake carrier forms a component which can be fastened to the vehicle and by means of which the electromechanical frame brake can be mounted on a support, for example a vehicle support structure.

[0009] Preferably, the guide surface is of cylindrical design. This ensures a symmetrical configuration with respect to the radial extent, thereby making it possible to absorb transverse forces perpendicular to the longitudinal extension of the frame brake particularly effectively.

[0010] In some embodiments, at least in a certain region or regions, the guide surface is formed concentrically with the piston side surface of the brake piston. This makes it possible to prevent the generation of eccentric forces during actuation of the brake piston. In other words, the alignment of the forces that occur is improved. The occurrence of shear forces relative to the longitudinal extent or the occurrence of tilting forces along the axial longitudinal extent of the frame brake is reduced or even prevented.

[0011] Alternatively, the axial linear guide is a sliding bearing on the brake carrier. As a result, mobility along the axial range of the frame brake can be ensured with low friction.

[0012] Preferably, the plain bearing is at an equal radial distance from the center of the cylindrical guide surface. A uniform force distribution to the plain bearing measured at the center of the cylindrical guide surface is thereby ensured. In other words, although two mutually spaced guide mechanisms are provided by the plain bearing and the cylindrical guide surface, they function as quasi-integral guide mechanisms. The arrangement is selected such that the relative arrangement itself does not induce eccentric forces. As a result, the housing rigidity of the frame brake is further improved.

[0013] In some embodiments, in a top view of the frame brake, the floating frame surrounds the brake carrier. Since the brake carrier ensures the connection to the vehicle structure, it represents a force application point relative to the weight of the frame brake to be carried. The geometry specified here ensures that the floating frame (which represents the axial support structure) surrounds the brake carrier as a force application point. As a result, the housing stiffness can be further increased.

[0014] Alternatively, the lateral struts are integrated into the cross member in one piece. This reduces the number of required components and the number of material transitions and connection points. This measure also leads to an improvement (increase) in the rigidity of the housing.

[0015] Preferably, the piston accommodating housing is screwed to the lateral strut at the end face. In this way, a releasable connection is formed between the piston accommodating housing and the cross member, thereby, for example, simplifying assembly or maintenance work.

[0016] As an option, the brake carrier has a window which is open radially towards the outside and through which the inner brake pad can be installed and removed without removing the floating frame.

[0017] Alternatively or cumulatively, a window is provided between the brake carrier and the cross member, which window is open radially towards the outside and through which the outer brake pad can be installed and removed without removing the floating frame.

[0018] In particular, the window opening radially toward the outside simplifies maintenance work for replacing the brake pad, since it does not require the floating frame to be removed. In addition, the air flow cross section for ventilating the brake pad can be increased due to the window. This improves the cooling of the brake pad.

[0019] Alternatively, the piston accommodation housing has a base on which the spindle is supported during actuation of the frame brake. Reaction forces due to the forces during actuation of the brake can thereby be absorbed. Starting from the base of the piston accommodation housing, the absorbed reaction forces can then be transmitted further, in particular to the cross member, in order to bring the outer brake pad into contact with the brake disc rotor.

[0020] In some embodiments, the piston accommodation housing has a plurality of axially extending cylindrically designed side walls, via which an axial guide can be provided for the spindle and / or the brake piston.

[0021] The side wall and the base delimit a free inner volume enclosed by the piston accommodating housing, said volume defining an inner space of the piston accommodating housing. The brake piston is at least partially accommodated in the inner space of the piston accommodating housing.

[0022] Preferably, an axial spindle bearing having a bearing contact surface is arranged between the base of the piston containing housing and the spindle. The axial spindle bearing provides the possibility of simultaneously supporting the spindle and, moreover, of enabling the spindle to rotate relative to the base of the piston containing housing. Furthermore, the spindle bearing can be used to compensate for the occurrence of eccentric forces.

[0023] In some embodiments, the spindle merges at its drive-side end via a surrounding shoulder into a drive shaft extension of reduced cross section. The shoulder has a convex section forming a ring on a spherical surface. The axial spindle bearing has a contact portion complementary to the bearing contact surface to allow a tilting movement of the spindle relative to the piston housing. In particular, the contact section of the axial spindle bearing is complementary to the convex spindle shoulder section forming a ring on the spherical surface. The complementarity of the contact section of the axial spindle bearing and the spindle shoulder section forming the spherical surface provides a centering mechanism, by which a uniform eccentric force component of the reaction force is compensated.

[0024] In other words, the radial extent of the spindle varies in the axial direction, precisely so that the spindle has a relatively small radial extent at the end opposite the brake pad and a relatively large radial extent at the brake pad end. Since the transition section of the spindle is arranged between these sections and forms the taper of the spindle with respect to the radial extent, the outer surface of the transition section can advantageously have a circumferential shoulder. This forms a convex section which forms a ring on the spherical surface and is in contact with the axial spindle bearing.

[0025] Preferably, the axial spindle bearing and the spindle section forming the spherical surface are rotationally symmetrical. As a result, the axial spindle bearing and the spindle section can be formed identically on all sides relative to the axis of rotation of the spindle.

[0026] As a particularly preferred feature, the bearing contact surface of the axial spindle bearing is spherical.

[0027] A spherical bearing contact surface is to be understood in particular as a bearing surface having a spherical contour.

[0028] Preferably, the spherical bearing contact surface is concave.

[0029] A restoring force in the direction of the axis of rotation of the spindle is then generated by the curvature of the spherical bearing contact surface. Here, the spherical profile ensures that the restoring force increases with increasing distance of the force application point from the axis of rotation of the spindle. This means that, when the force application point is appropriately chosen, a greater restoring force is generated which forces the spindle to orient along the axis of rotation.

[0030] Alternatively, the spherical bearing contact surface of the axial spindle bearing has a first radius of curvature and the complementary contact surface of the transition section has a second radius of curvature. Advantageously, the first radius of curvature and the second radius of curvature are different. This results in a line contact (circular line) between the complementary contact surface and the bearing contact surface, in particular when no force is applied. When an action force and thus a reaction force is generated, starting from a line contact, when the force increases, a surface contact is formed between the contact surfaces due to the elastic flattening of the surfaces. The contact surfaces are therefore in close contact. In this way, it can be ensured that the centering effect is even more pronounced when the force increases.

[0031] In particular, the axial spindle bearing can be an axial rolling bearing.The axial spindle bearing ensures the rotatability of the spindle relative to the piston accommodation housing without generating increased friction torques in the process.

[0032] In particular, on the opposite side of the spherical bearing contact surface, the axial spindle bearing can have a planar contact surface on the bearing ring, by means of which the axial spindle bearing is axially supported on the adjacent rolling elements. As a result, the axial spindle bearing with the spherical bearing contact surface and the opposite planar contact surface ensures a contact between the rolling elements and the bearing ring that is as uniform as possible, since the rotational degree of freedom transversely to the axis of rotation of the spindle is not removed, so that microscopic and macroscopic angular displacements or eccentric force effects can be compensated.

[0033] In a particularly preferred embodiment, the axial spindle bearing is supported on the base of the piston housing. The piston housing is oriented so that the open end is arranged in the direction of the brake disc rotor and the inner brake pad, that is to say on the brake pad side, and so that the base of the piston housing is arranged opposite to the open end in the axial direction. This means that the generated action force acts in the axial direction along the open end of the piston housing, while the reaction force generated thereby acts in the direction of the base. Since the axial spindle bearing is supported on the base of the piston housing, the axial spindle bearing is arranged between the base and the spindle in the direction of action of the reaction force. This enables the axial spindle bearing to absorb the reaction force in a particularly effective manner.

[0034] As a particularly preferred feature, the base of the piston accommodation housing has a raised platform portion which extends axially from the base in the direction of the brake disc rotor. This enables the axial spindle bearing to be positioned further into the interior of the brake piston. In this way, the axial length of the piston accommodation housing of the frame brake can be shortened and the required installation space in the axial direction can be reduced.

[0035] Preferably, a bearing disk is arranged axially between the base of the piston housing and the rolling elements of the axial spindle bearing, which bearing disk is pressed into the piston housing so that the bearing disk is fixed against rotation by friction engagement and / or forced engagement. Due to its geometry, the piston housing represents a more complex component than the bearing disk. By means of the bearing disk, the base of the piston housing can be protected from damage caused by the axial spindle bearing (if the axial spindle bearing is in direct contact with the base), which damage may generally be caused in the case of a worn axial spindle bearing and under the action of these reaction forces. Therefore, if necessary, only the bearing disk or the entire axial spindle bearing needs to be replaced, without having to replace the piston housing.

[0036] In particular, the bearing disc can have two opposing planar contact surfaces, wherein one planar contact surface is in contact with the base of the piston containing housing and one planar contact surface is in contact with the rolling elements. An additional advantage is obtained, namely that the production effort required to ensure the quality of the contact surface of the base of the piston containing housing can be reduced.

[0037] The rolling elements of the axial spindle bearing then roll on the one hand on the planar contact surface of the bearing ring at the brake pad end of the axial spindle bearing and on the other hand on the planar contact surface of the bearing disk which also forms the bearing ring.

[0038] A bearing arrangement is provided between the drive shaft extension of the spindle with reduced cross section and the piston housing, for example by means of a ball bearing or a plain bearing. Axial mobility of the spindle relative to the piston housing is prevented by a fastening device, for example a snap ring. The snap ring can be arranged in a radial groove of the piston housing, for example more precisely starting from the base of the piston housing, opposite the brake disc rotor. The snap ring can also be multi-layered.

[0039] Preferably, the brake piston is formed as a spindle nut by forming a spindle thread on its inner side. The spindle drive is configured to ensure the linear mobility of the brake piston relative to the spindle. With the help of the spindle drive, the brake piston used as the spindle nut can be moved in the axial direction. In this way, the brake piston can subject at least one brake pad (inner brake pad) of the brake to an action force, thereby being able to produce a frictional engagement with the brake disc rotor. This means that the spindle can rotate around the axis of rotation, and the rotation causes a translational movement of the brake piston along the axial direction to provide an action force for at least one brake pad (the inner brake pad). Due to the generated action force, an oppositely directed reaction force is generated, which usually has an eccentric force component. Typically, these force components can generate shear forces, but these force components can be absorbed and compensated by multiple guide mechanisms, namely lateral struts, axial linear guides and sockets with cylindrical guide surfaces.

[0040] In the case of the electromechanical frame brake described here, a rotation lock is provided between the piston housing and the brake piston (the brake piston is mounted in the piston housing in a linearly movable manner). The rotation lock allows a linear movement of the brake piston, but prevents the brake piston from rotating relative to the piston housing.

[0041] Preferably, the rotation lock comprises a slotted hole with which the rotation securing element engages.

[0042] As an option, a rotational fastening device is provided between the piston housing and the brake support of the frame brake. For example, a forced connection can be provided between the piston housing and the brake support, which prevents the piston housing from rotating relative to the brake support.

[0043] The positive connection provided for securing the piston accommodation housing against rotation can have a slot-and-key connection, a tangential pin connection or a slotted hole in which the rotation-securing element engages.

[0044] Alternatively, an axially extending seal is arranged radially between the brake piston and the brake support. In particular, the brake support and the inner guide surface of the piston receiving housing for the brake piston can thereby be protected from contaminants (e.g., worn brake material). In this way, the service life of the spindle drive and the socket for the piston receiving housing, in which the piston receiving housing is mounted in an axially movable manner, can be extended.

[0045] Preferably, a circumferential bellows seal is arranged radially on the outside between the brake support and the piston housing. The bellows seal prevents contaminants from entering the socket for the axially movably mounted piston housing from the outside. This prolongs the service life of the guide mechanism of the socket.

[0046] In some embodiments, the brake support has a reset element. Preferably, the socket of the brake support has such a reset element. The reset element is configured to return the piston housing to an initial position, in particular, to reset along the axial longitudinal extent of the frame brake, when the frame brake is not subjected to any force. When a force is applied, the piston housing moves in an axial direction by the reaction force that occurs, more particularly, in a direction opposite to the brake disc rotor. In other words, the distance between the piston housing and the brake disc rotor increases. As a result, the outer brake pad contacts the brake disc rotor. When the application of the force ends, the reaction force also no longer occurs. In this case, the reset element ensures that the piston housing and therefore also the cross member connected to the piston housing and the outer brake pad move back to the initial position (position without force), i.e. in the direction of the brake disc rotor. This ensures that the outer brake pad is free relative to the brake disc rotor.

[0047] Preferably, the socket of the brake support has a groove in which the reset element is arranged. With the help of the groove, installation space can be saved along the axial extent of the frame brake. In addition, this arrangement also enables the reset element to be used as an additional sealing element, so that the ingress of contaminants can be avoided.

[0048] Alternatively, the reset element has an annular body. The reset element is arranged radially on the outside of the housing side surface of the piston receiving housing. Circular symmetry with respect to the restoring force generated by the reset element is thereby ensured. In addition, the alignment of the frame brake is improved.

[0049] Preferably, the reset element comprises an elastic material, in particular an elastomer. The reset element can then be adapted particularly well to the available installation space between the brake carrier and the piston housing. In addition, the durability of the reset element is increased. When a force is applied to the frame brake, i.e. when the frame brake is actuated, the reset element preferably deforms and stores deformation energy in the process. Here, the reset element is operatively connected to the brake carrier and the piston housing so that when the brake is released, i.e. when the force applied to the frame brake is removed, the stored deformation energy is released and the piston housing and therefore also the cross member connected to the piston housing and the outer brake pad are moved back to the initial position as already described.

[0050] Alternatively, the restoring element can also be designed as a metal spring, in particular as a circumferential metal spring.

[0051] In some embodiments, the bellows seal can also be omitted. The resetting element can then additionally ensure the sealing function of the bellows seal. The frame brake thus advantageously has fewer components. Furthermore, production is less complicated.

[0052] Alternatively, the brake piston has an end wall on the brake pad side, which, when the brake is applied, presses against the inner brake pad of the frame brake. The end wall can have an end face in the form of a circular ring. As a result, the force application point of the force acting on the brake pad is shifted radially outwards, allowing the brake pad to be loaded more evenly in terms of area. That is, the application of force to the brake pad is improved.

[0053] Preferably, the spindle drive has a recirculating ball screw. In the case of a recirculating ball screw, the balls transmit the forces between the spindle and the brake piston acting as a spindle nut. Due to the rolling of the balls, friction and wear are reduced. The recirculating ball screw is not self-locking. This means that, due to the inherent elasticity in the system, the brake piston also automatically moves back to the retracted position when it is no longer actively loaded into the extended position by a motor, such as an electric motor.

[0054] Preferably, rotation of the spindle is provided by means of a reduction gear assembly of an electric motor and a frame brake, the reduction gear assembly meshing with a drive shaft extension of the spindle.

[0055] As an option, the piston housing (in which the spindle is mounted) has a positively movable connection with a gear assembly for driving the spindle. This ensures the centering of the gear assembly of the driver relative to the piston housing.

[0056] Preferably, the positive connection between the piston containing housing and the gear assembly of the driver has a slot-and-key connection or a hub-and-shaft connection with spline teeth.

[0057] In particular, the electromechanical frame brake may be configured to be used as a vehicle brake including brake pads and a brake disc rotor.

[0058] According to another aspect, there is also provided a vehicle having an electromechanical frame brake as described above.

[0059] Alternatively, the vehicle may specifically include a motor vehicle, i.e. a road vehicle. Alternatively, the vehicle may also include other types of vehicles, such as a two-wheeled vehicle, a motorcycle, etc. In general, in the present case, a vehicle is understood to refer to a device configured to transport objects, goods or people between different destinations. Examples of vehicles are land-based vehicles, such as motor vehicles, electric vehicles, hybrid vehicles, etc. In the present context, a vehicle may preferably be considered to be a road vehicle, such as a car, a truck, a bus, etc.

[0060] All features explained in relation to various aspects may be combined with other aspects alone or in (sub)combinations. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The present disclosure and further advantageous embodiments and developments thereof are described and explained in more detail below with reference to the examples shown in the accompanying drawings. In the drawings:

[0062] Figure 1 shows a simplified schematic isometric view of an electromechanical frame brake according to one embodiment of the present invention;

[0063] Figure 2 shows a simplified schematic front view of an electromechanical frame brake according to the invention;

[0064] Figure 3 A simplified schematic top view of an electromechanical frame brake according to the invention is shown;

[0065] Figure 4 shows a simplified schematic bottom view of an electromechanical frame brake according to the invention;

[0066] Figures 5 to 8 Shown as Figure 2 Simplified schematic cross-sectional views of an electromechanical frame brake according to the invention are shown along section lines AA, BB, CC and DD;

[0067] Fig. 9 Another simplified schematic diagram of an electromechanical frame brake according to the invention is shown for illustrating the modification of the brake pads. DETAILED DESCRIPTION

[0068] The following detailed description in conjunction with the accompanying drawings (in which like numbers refer to like elements) is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Any embodiment described in this disclosure is purely by way of example or illustration and should not be construed as preferred or advantageous over other embodiments.

[0069] All features disclosed below with respect to the exemplary embodiments and / or the accompanying drawings may be combined with features of various aspects of the present disclosure (including features of the preferred embodiments) alone or in any subcombination, as long as the resulting feature combination is beneficial to those skilled in the art.

[0070] Figure 1 A simplified schematic isometric view of an electromechanical frame brake 10 according to one embodiment of the present invention is shown.

[0071] Along the axial extension direction 12 , the electromechanical frame brake 10 comprises a brake actuator unit 14 and a drive unit 16 . The brake actuator unit 14 comprises a support structure which is designed as a floating frame 18 and which is movable along the axial extension direction 12 .

[0072] The electromechanical frame brake 10 has a brake carrier 20 , by means of which the frame brake 10 can be mounted on a support, for example a vehicle support structure.

[0073] Axially on the outside with respect to the brake carrier 20 , the floating frame 18 has a cross member 22 to which the outer brake pads of the frame brake 10 are at least indirectly coupled.

[0074] Furthermore, the floating frame 18 has a piston receiving housing 24 for guiding a brake piston therein. Starting from the brake carrier 20 , the piston receiving housing 24 is arranged opposite the cross member 22 .

[0075] The cross member 22 is coupled to the piston accommodation housing 24 via radially outer lateral struts 26 , in which respective retaining screws 28 engage.

[0076] The lateral struts 26 are formed integrally with the cross member 22. The integral formation of the lateral struts 26 and the cross member 22 makes it possible to avoid the otherwise necessary assembly mechanism and material transition, thereby increasing the housing rigidity of the frame brake 10, in particular the housing rigidity of the floating frame 18.

[0077] Starting from the cross member 22 , the lateral struts 26 extend beyond the brake carrier 20 in the axial extension direction 12 . This results in an additional increase in the housing rigidity of the floating frame 18 of the frame brake 10 .

[0078] The increase in housing stiffness enables shear forces generated during actuation of the frame brake 10 to be better compensated and dissipated than before.

[0079] The cross member 22 is also coupled to the brake carrier 20 via an axial linear guide 30 which has a sliding bearing 31 in which a corresponding retaining screw 32 engages. The axial linear guide 30 extends along the axial extension direction 12 .

[0080] The axial linear guide 30 ensures axial mobility of the floating frame 18 relative to the brake carrier 20. Since the piston housing 24 is rigidly coupled to the cross member 22 of the floating frame 18, the piston housing 24 can also be moved relative to the brake carrier 20 by means of the axial linear guide 30.

[0081] Figure 2 A simplified schematic front view of an electromechanical frame brake 10 according to the invention is shown.

[0082] It can be seen here that the axial linear guide 30 is at the same radial distance 36 relative to the rotation axis 34 of the brake actuator unit 14 of the frame brake 10 (the rotation axis 34 also corresponds to the rotation axis of the underlying brake disk rotor in the ideal case of compensated shear and tilting forces). In other words, the axial linear guide 30 is arranged symmetrically relative to the rotation axis 34 of the frame brake 10. The possibility of eccentric forces caused by the axial linear guide 30 can thereby be prevented.

[0083] The brake carrier 20 comprises a corresponding coupling structure 37 , by means of which the frame brake 10 can be mounted, for example, on a vehicle support structure.

[0084] This figure also shows Figures 5 to 8 The cross-sectional views shown in FIG. 1 are section lines AA, BB, CC and DD.

[0085] Figure 3 shows a simplified schematic top view of an electromechanical frame brake 10 according to the invention, and Figure 4 A simplified schematic bottom view of an electromechanical frame brake 10 according to the invention is shown.

[0086] A receiving space 38 for the brake disk rotor is arranged in the region of the brake carrier 20 .

[0087] An outer brake pad 40 is mounted on the cross member 22. Starting from the accommodation space 38, an inner brake pad 42 is arranged in the opposite direction along the axial extension direction 12, and thus during operation, the brake disc rotor can contact the outer brake pad 40 and the inner brake pad 42 from opposite directions. The brake disc rotor is thus surrounded by the two brake pads 40, 42 in the axial extension direction 12.

[0088] While the inner brake pad 42 can usually be actively moved in the direction of the brake disc rotor by a brake piston of the brake actuator unit 14 , the contact between the outer brake pad 40 and the brake disc rotor is ensured by the mobility of the floating frame 18 .

[0089] Furthermore, it can be seen that the brake carrier 20 forms a window 44 which is open radially toward the outside for the inner brake pad 42 .

[0090] Furthermore, a further window 46 is formed between the brake carrier 20 and the cross member 22 , which window is open radially toward the outside for the outer brake pad 40 .

[0091] Through the windows 44 , 46 , the outer brake pad 40 and the inner brake pad 42 can be removed from or inserted into the frame brake 10 , for example for assembly purposes or in the case of replacement as part of maintenance work. In this context, Fig. 9 Another simplified schematic diagram of an electromechanical frame brake 10 according to the invention is shown, the purpose of which is to illustrate the variation of brake pads 40, 42 that can be inserted through windows 44, 46. This makes it possible to replace brake pads 40, 42 in a process that advantageously does not require removal of other parts of the frame brake 10.

[0092] exist Figure 3 and Figure 4 In the illustration of FIG. 4 , it can also be seen that the axial linear guide 30 has an axially flexible guide seal 48 , by means of which the linear guide 30 can be protected from contaminants.

[0093] Furthermore, in the region of the piston accommodation housing 24, the frame brake 10 comprises a circumferential bellows seal 50 which extends between the brake carrier 20 and the piston accommodation housing 24. Since the brake carrier 20 provides a guide for the piston accommodation housing 24, as will be explained in further detail below, this guide can be protected from contaminants by the bellows seal 50.

[0094] Figures 5 to 8 Shown as Figure 2 A simplified schematic sectional view of an electromechanical frame brake 10 according to the invention is shown along the section lines AA, BB, CC and DD.

[0095] In the ideal case of compensated shear and tilting forces, the rotation axis 34 of the brake actuator unit 14 of the frame brake 10 also corresponds to the rotation axis of the underlying brake disc rotor and the central main axis of the entire housing of the frame brake 10 (essentially defined by the brake carrier 20 ).

[0096] During operation, the inner brake pad 42 actively absorbs the force Fz applied by the brake actuator unit 14 in the direction of the brake disc rotor.

[0097] The axially movable floating frame 18 ensures that the brake pad 40 located on the outside in the axial direction is also acted upon by the force Fz. In this case, the force Fz is distributed substantially uniformly in size between the inner brake pad 42 and the outer brake pad 40. As a result of the contact pressure provided, a frictional engagement with the brake disc rotor arranged in the accommodation space 38 can therefore be ensured for both brake pads 40, 42, which serves to decelerate or hold the vehicle.

[0098] The frame brake 10 also has an electromechanical actuation unit, which serves as a drive unit 16 and is used to generate a force Fz together with the brake actuator unit 14. The drive unit 16 is arranged opposite the brake disc rotor in the axial extension direction 12 relative to the brake actuator unit 14. The drive unit 16 includes at least one electric motor, a reduction gear assembly and a parking brake mechanism.

[0099] The components of the drive unit 16 are coupled to the piston housing 24. Their weight is therefore supported by the brake support 20. The housing part of the frame brake 10 is usually designed as a skeleton-like frame made of metal or fiber-reinforced plastic. The drive unit 16 forms a closed subassembly that can be assembled separately.

[0100] The brake actuator unit 14 comprises a main shaft 52 having a drive shaft extension 54, a brake pad-side shank section 56 and a transition section having a shoulder 58. The shoulder 58 is arranged along the axis of rotation 34 of the main shaft 52 between the drive shaft extension 54 and the shank section 56. The diameter of the drive shaft extension 54 of the brake actuator unit 14 in the radial direction is smaller than the diameter of the shank section 56 in this direction. The main shaft 52 thus tapers in the region of the transition section with respect to its diameter.

[0101] The brake actuator unit 14 also has a spindle nut 60, which in the present case is configured as a brake piston 62. In the present case, the spindle drive 64 of the brake actuator unit 14 is designed as a recirculating ball screw without self-locking. This means that the spindle drive 64 comprises a spindle thread 66, in which balls 68 are arranged and roll. The spindle 52 and the spindle nut 60 have corresponding race components, which together form the spindle thread 66. The balls 68 can allow a translational movement of the spindle nut 60 along the axis of rotation 34 relative to the spindle 52 along a ball race 70 of the spindle thread 66. For this purpose, the ball race 70 is at least partially formed in the shank section 56 of the spindle 52 and in the spindle nut 60.

[0102] The diameter of the ball race 70 corresponds to the diameter of the balls 68 taking into account manufacturing tolerances and the required gap dimensions.

[0103] Here, the rotation of the spindle 52 is ensured by the electric motor of the drive unit 16, which is engaged with the drive shaft extension 54 of the spindle 52 via a reduction gear assembly. The inclination of the spindle drive 64, in particular the inclination of the ball race 70, then has the effect that the rotation of the spindle 52 causes a translational movement of the spindle nut 60. The spindle nut 60, designed as a brake piston 62, transmits this movement to the brake pads 40, 42. The resulting force Fz is proportional to the torque generated by the drive unit 16 at the drive shaft extension 54.

[0104] The inner brake pad 42 actively receives the force Fz generated in this way and emanating from the brake piston 62 .

[0105] The brake actuator unit 14 further comprises a piston accommodating housing 24 having a radial inner side 72 and a base 74. The open end of the piston accommodating housing 24 is arranged on the brake pad side along the axis of rotation 34. This means that the base 74 is arranged at the end of the piston accommodating housing 24 opposite the brake disc rotor. The base 74 has a through hole 76 for the drive shaft extension 54 of the main shaft 52, which is held in the through hole 76 by a radial bearing 78 (sliding bearing).

[0106] Axial mobility of the spindle 52 relative to the piston housing 24 is prevented by a securing device, such as a snap ring 80. The snap ring 80 is provided on the side of the base 74 of the piston housing 24 opposite the shank section 56 of the spindle 52.

[0107] The piston housing 24 is coupled to the drive unit 16 by a forced connection 82 such that the reduction gear assembly is centered relative to the piston housing 24. The forced connection 82 may comprise, for example, a slot-and-key connection or a shaft-hub connection with spline teeth.

[0108] The radially inner inner side 72 and the base 74 define an inner space 84 of the piston housing 24, in which at least the spindle 52 and the spindle nut 60 or the brake piston 62 are at least partially arranged. Due to the linear mobility of the brake piston 62 designed as the spindle nut 60, this component can also be arranged at least partially outside the inner space 84.

[0109] The piston receiving housing 24 makes it possible to design the brake actuator unit 14 as a separate subassembly.

[0110] The brake carrier 20 comprises a socket 86 with a cylindrical guide surface 88. The design of the cylindrical guide surface 88 of the brake carrier 20 corresponds to the radially outer housing side surface 90 of the piston accommodation housing 24. Furthermore, the cylindrical guide surface 88 of the brake carrier 20 is formed concentrically with a piston side surface 91 of the brake piston 62 designed as the spindle nut 60. In the ideal case of compensating for transverse forces, the center of the cylindrical guide surface 88 and the center of the piston side surface 91 of the brake piston 62 coincide with the rotation axis 34.

[0111] The cylindrical guide surface 88 of the brake support 20 is delimited by a base section 92 of the brake support 20. The cylindrical guide surface 88 and the base section 92 define a socket 86 in which the piston accommodation housing 24 is mounted in a manner that allows axial movement. In this case, the bellows seal 50 extends circumferentially between the brake support 20 and the piston accommodation housing 24 and delimits the socket 86 in the direction opposite to the base section 92 of the brake support 20 along the axial extension direction 12.

[0112] A rotation securing device 94 is formed between the brake carrier 20 and the piston accommodation housing 24 , by which the piston accommodation housing 24 is prevented from rotating relative to the brake carrier 20 .

[0113] Furthermore, a rotation lock 96 is formed between the piston accommodation housing 24 and the spindle nut 60 , by which a rotation of the spindle nut 60 relative to the piston accommodation housing 24 is prevented.

[0114] The piston housing 24, in which the spindle drive 64, the spindle nut 60 designed as a brake piston 62 and the spindle 52 are accommodated, is thus radially and axially supported as a subassembly in the socket 86 of the brake carrier 20, while ensuring axial mobility. Only a relative rotation of the spindle 52 and the balls 68 of the spindle drive 64 is allowed, and a relative rotation of other components is otherwise prevented.

[0115] As a result of the generated action force Fz, a reaction force Fr is generated along the rotation axis 34, which is opposite to the action force Fz. Due to the elastic expansion of the components of the frame brake 10, an angular misalignment usually occurs between the rotation axis of the brake disc rotor and the cylinder axis of the frame brake 10, as a result of which the reaction force Fr has eccentric force components. These eccentric force components can lead to instabilities of the components of the brake actuator unit 14 in the radial direction, in particular in the case of a core diameter of the spindle drive 64 that is smaller than the outer diameter of the bearing for absorbing the reaction force Fr.

[0116] In the present case, therefore, the brake actuator unit 14 comprises a rotationally symmetrical axial spindle bearing 98, which is embodied as an axial bearing with a bearing ring 100 having a spherical bearing contact surface 102 arranged on the brake pad side. The axial spindle bearing 98 is in contact with a shoulder 58 of the spindle 52, which has a convex section 104 forming a ring on the spherical surface. The spherical bearing contact surface 102 is concave and has a design complementary to the section 104.

[0117] The bearing ring 100 also has a planar contact surface 106 which is arranged opposite the spherical bearing contact surface 102 along the rotational axis 34 .

[0118] Furthermore, the brake actuator unit 14 has rolling elements 108 which are in contact with the planar contact surface 106 .

[0119] The piston accommodating housing 24 includes a plateau portion 110 extending axially from the base portion 74 in the direction of the brake disc rotor.

[0120] Furthermore, a bearing disk 112 is arranged between the axial spindle bearing 98 and the base 74 of the piston accommodating housing 24, which has two opposite planar contact surfaces along the axis of rotation 34 and is pressed into the piston accommodating housing 24 in a rotationally fixed manner by friction and / or forced engagement. One of the contact surfaces of the bearing disk 112 is in contact with a plateau 110 of the piston accommodating housing 24. The rolling element 108 rolls on the other of the two contact surfaces of the bearing disk 112. The plateau 110 shortens the required axial length of the piston accommodating housing 24, thereby making it possible to save installation space in the axial extension direction 12.

[0121] The reaction force Fr thus generated is transmitted from the shank section 56 of the spindle 52 via the shoulder 58 to the spherical bearing contact surface 102 of the axial spindle bearing 98 and from there is absorbed by the base 74 of the piston accommodation housing 24 via the rolling elements 108 and the bearing disk 112 .

[0122] Via the lateral struts 26 , the reaction force Fr is transmitted to the cross member 22 , thereby enabling the outer brake pad 40 to move in the direction of the brake carrier 20 in order to ensure contact between the outer brake pad 40 and the brake disc rotor.

[0123] The mobility of the cross member 22 relative to the brake carrier 20 is ensured by the axial linear guides 30. These guide means act together (in a quasi-unitary manner) since they are equidistant 36 from the center 114 of the guide surface 88 relative to the cylindrical guide surface 88, which center 114 coincides with the axis of rotation 34. Thus, since previous frame brakes did not have additional guide means of the socket 86, a better compensation of shear forces can be provided than has hitherto occurred when the frame brake 10 is actuated.

[0124] Since the socket is provided by the brake carrier 20 itself, it is also arranged close to the center of gravity of the frame brake 10. In this case, the guide means are advantageously arranged on both sides of the center of gravity of the frame brake. The guide means ensured by the axial linear guide 30 is arranged axially on the outside relative to the brake carrier. In contrast, the guide means of the socket 86 of the brake carrier is arranged axially on the inside. This can provide a better compensation of tilting forces that may occur due to the mass distribution of the components of the frame brake 10 in the axial extension direction 12. As a result, the housing rigidity of the frame brake 10 is increased. This ensures the advantages mentioned above with regard to the service life, the stability of the desired brake application path and the reduction of the fuel consumption of the vehicle with the frame brake 10.

[0125] In particular, in order to protect the spindle drive 64 , an axially extending seal 116 extends between the spindle nut 60 and the brake carrier 20 .

[0126] In the lower left and right, Figure 5 Two embodiments 118A and 118B of the receptacle 86 of the brake carrier 20 are shown.

[0127] The location of embodiments 118A and 118B is Figure 5 shown in the main image.

[0128] Typically, the socket 86 of the brake support 20 has a cylindrical guide surface 88 in which the housing side surface 90 of the piston receiving housing 24 is mounted in a manner that allows axial movement. In the embodiment 118A, it can be seen that a gap 120 is formed between the guide surface 88 and the housing side surface 90. The brake support 20 includes a groove 122, which is located radially outward relative to the housing side surface 90 of the piston receiving housing and in which a reset element 124 is arranged.

[0129] In the present case, the reset element 124 is formed by an elastically deformable elastomer and is shaped as an annular body. However, it is also conceivable that the reset element 124 is designed as a metal spring. Therefore, here, the reset element 124 surrounds the housing side surface 90 of the piston accommodating housing 24.

[0130] By means of the reset element 124, the axially movable piston accommodation housing 24 can be pushed back into the initial position, i.e. in the axial direction towards the brake disc rotor, without the application of force. Since the outer brake pad 40 is directly coupled to the piston accommodation housing 24 via the cross member 22, the outer brake pad 40 (on the far side of the brake disc rotor) is then moved away from the rotor, resulting in an increase in the distance between the outer brake pad 40 and the brake disc rotor. Thus, a defined initial position of the outer brake pad 40 can be ensured by the reset element 124, which initial position is released by the reset element 124.

[0131] Furthermore, the restoring element 124 ensures the centering of the piston receiving housing 24 .

[0132] In the embodiment 118B, the bellows seal 50 is omitted. In this case, the restoring element 124 also ensures the sealing function ensured by the bellows seal 50 in the embodiment 118A. This means that, in particular with regard to the guidance of the housing side surface 90 of the piston receiving housing 24 in the guide surface 88 of the brake carrier 20, the socket 86 can be protected from contaminants by the restoring element 124. In addition, the spindle drive 64 is also protected from contaminants.

[0133] In both embodiments 118A and 118B, the punched edge of the groove 122 which is further away from the brake disc rotor (during the production of the groove, two punched edges are formed by penetration of a turning tool or a punching tool) can be provided in each case with a chamfer 130, by means of which the recoil effect (i.e. the storage and release of the deformation energy of the elastic annular body) and thus the return of the piston housing are assisted, primarily when using an elastomer.

Claims

1. An electromechanical frame brake (10), the electromechanical frame brake comprising: A floating frame (18) assembled from a plurality of parts; a brake piston (62) which can be axially displaced by means of a spindle drive (64) and is seated on a spindle (52) of the spindle drive (64) and is guided in a piston receiving housing (24), The floating frame (18) comprises the piston housing (24), lateral struts (26) and an outer cross member (22), which is connected to the piston housing (24) via the lateral struts (26) and carries an outer brake pad (40). The floating frame (18) is mounted via an axial linear guide (30) to float relative to a brake support (20) of the frame brake (10) and to be axially movable relative to the brake support (20), and the brake support (20) has a socket (86) having a guide surface (88) for the piston accommodating housing (24), and the piston accommodating housing (24) is mounted in the socket in an axially movable manner.

2. The electromechanical frame brake (10) according to claim 1, characterized in that At least in a certain region or certain regions, the guide surface (88) is formed concentrically with a piston side surface (91) of the brake piston (62), and / or the guide surface is of cylindrical design.

3. The electromechanical frame brake (10) according to claim 1 or 2, characterized in that The axial linear guide (30) is a sliding bearing (31) on the brake support (20).

4. The electromechanical frame brake (10) according to claim 3, characterized in that The sliding bearing (31) is at an equal radial distance from the center of the guide surface (88).

5. The electromechanical frame brake (10) according to any one of the preceding claims, characterized in that In a top view of the frame brake (10), the floating frame (18) surrounds the brake carrier (20).

6. Electromechanical frame brake (10) according to any one of the preceding claims, characterized in that The lateral struts (26) are integrated into the cross member (22).

7. The electromechanical frame brake (10) according to claim 6, characterized in that The piston accommodation housing (24) is screwed to the lateral strut at the end face.

8. Electromechanical frame brake (10) according to any one of the preceding claims, characterized in that The brake support (20) has a window (44) which is radially open toward the outside and through which an inner brake pad (42) can be installed and removed without removing the floating frame (18), and / or a window (46) is provided between the brake support (20) and the cross member (22), which is radially open toward the outside and through which the outer brake pad (40) can be installed and removed without removing the floating frame (18).

9. Electromechanical frame brake (10) according to any one of the preceding claims, characterized in that The piston containing housing (24) has a base (74) on which the spindle (52) is supported during actuation of the frame brake (10).

10. The electromechanical frame brake (10) according to claim 9, characterized in that An axial spindle bearing (98) having a bearing contact surface (102) is arranged between the base (74) of the piston containment housing (24) and the spindle (52).

11. The electromechanical frame brake (10) according to claim 10, characterized in that The main shaft (52) merges at its drive-side end via a circumferential shoulder (58) into a drive shaft extension (54) of reduced cross-section, wherein the shoulder (58) has a convex section (104) forming a ring on a spherical surface, and the axial main shaft bearing (98) has a contact portion complementary to the bearing contact surface (102) to allow tilting movement of the main shaft (52) relative to the piston accommodating housing (24).

12. Electromechanical frame brake (10) according to any one of the preceding claims, characterized in that The brake piston (62) is formed as a spindle nut (60) by forming a spindle thread (66) on its inner side (72).

13. The electromechanical frame brake (10) according to any one of the preceding claims, characterized in that An axially extending seal (116) is radially arranged between the brake piston (62) and the brake support (20).

14. Electromechanical frame brake (10) according to any one of the preceding claims, characterized in that A circumferential bellows seal (50) is arranged radially on the outside between the brake support (20) and the piston receiving housing (24).

15. The electromechanical frame brake (10) according to any one of the preceding claims, characterized in that The brake support (20), in particular the socket (86) of the brake support (20), has a reset element (124) which is configured to return the piston accommodating housing (24) to an initial position when the frame brake is not subjected to any force.

16. The electromechanical frame brake (10) according to claim 15, characterized in that The socket (86) of the brake holder (20) has a recess (122) in which the restoring element (124) is arranged.

17. The electromechanical frame brake (10) according to claim 15 or 16, characterized in that The restoring element (124) has an annular body, wherein the restoring element is arranged radially on the outside of a housing side surface (90) of the piston accommodating housing (24).

18. The electromechanical frame brake (10) according to any one of claims 15 to 17, characterized in that The restoring element (124) comprises an elastic material, in particular an elastomer.

Images