Operating device for a braking system, braking system

Abstract

The present invention relates to an operating device (1) for a braking system (2), comprising an electromechanical machine (21) arranged within a motor housing (20), wherein a rotor (22) of the electromechanical machine (21) is arranged non-rotatably on a drive shaft (23) which is rotatably supported, and an actuator element (3) which is slidably supported, the drive shaft (23) being connected to the actuator element (3) by a transmission device (29) such that the actuator element (3) is slidable by the electromechanical machine (21), the transmission device (29) having a worm drive (30) having a worm shaft (31) and a worm wheel (32), and the drive shaft (23) forming the worm shaft (31). 【Solution means】The rotational axis (24) of the drive shaft (23) is oriented perpendicular to the sliding axis (4) of the actuator element (3).

Description

Technical Field

[0001] The present invention relates to an operating device for a braking system, comprising an electromechanical machine arranged in a motor housing, wherein a rotor of the electromechanical machine is arranged non-rotatably relative to a drive shaft that is rotatably supported, and further comprising an actuator element that is slidably supported, and the drive shaft is connected to the actuator element by a transmission mechanism device such that the actuator element is slidable by the electromechanical machine, and the transmission mechanism device has a worm transmission mechanism having a worm shaft and a worm wheel, and the drive shaft forms the worm shaft.

[0002] Furthermore, the present invention relates to a braking system.

Background Art

[0003] Automotive hydraulic brake systems typically include a plurality of friction brake devices. The friction brake devices are in an interaction relationship with the operating device of the brake system such that the friction brake devices can be operated by the operating device. As the electrification of automobiles progresses, the electrification of the operating devices of brake systems is also advancing. In this regard, it is known to equip the operating device for the brake system with an electromechanical machine disposed within a motor housing, and the rotor of the electromechanical machine is disposed non-rotatably relative to a drive shaft that is rotatably supported. To enable the operation of the friction brake devices by the operating device, the operating device additionally includes an actuator element that is slidably supported. The drive shaft is connected to the actuator element by a transmission mechanism device such that the actuator element can be slid by the electromechanical machine. The transmission mechanism device is formed to convert the rotation of the drive shaft into a translational movement of the actuator element. The friction brake devices can thus be operated by the electromechanical machine. In this case, it is known to use a worm transmission mechanism having a worm shaft and a worm wheel within the transmission mechanism device. A high transmission ratio can be achieved by the worm transmission mechanism. Accordingly, the worm transmission mechanism achieves that the noise generation of the operating device during operation is slight. Typically, the worm shaft is formed by the drive shaft at that time. Due to being formed as the worm shaft, the drive shaft has a thread screw thread. SUMMARY OF THE INVENTION

[0004] The operating device according to the present invention having the features of claim 1 has the advantage that the operating device can be realized at low cost. For this purpose, according to the present invention, the rotational axis of the drive shaft is oriented perpendicular to the sliding axis of the actuator element. By orienting the rotational axis of the drive shaft relative to the sliding axis of the actuator element according to the present invention, it is possible to achieve a mechanically simple and mechanically robust connection of the drive shaft to the actuator element. Preferably, the worm wheel is arranged coaxially with respect to the actuator element, and as a result, the longitudinal central axis of the worm wheel corresponds to the sliding axis of the actuator element. This configuration of the operating device has the advantage that the operating device is formed to be compact and thus requires less space for assembly. Preferably, the thread of the drive shaft meshes with the external tooth row of the worm wheel.

[0005] According to a preferred embodiment, it is contemplated that the transmission mechanism device has a spindle transmission mechanism that is technically connected downstream of the worm transmission mechanism. By means of the spindle transmission mechanism, it is surely possible to convert the rotation of the drive shaft into a translational movement of the actuator element. In addition, the manufacturing cost associated with the use of the spindle transmission mechanism is low. Preferably, the spindle transmission mechanism has a rotatably supported spindle nut and a threadedly supported threaded spindle. Preferably, the spindle nut forms the worm wheel. Alternatively, the worm wheel is preferably arranged non-rotatably on the spindle nut. Preferably, the threaded spindle forms the actuator element. Alternatively, the threaded spindle is preferably connected to the actuator element such that the actuator element is slidable by the threaded spindle.

[0006] According to an alternative embodiment, preferably, it is contemplated that the transmission mechanism device has a ball screw mechanism that is technically connected to the transmission mechanism downstream of the worm transmission mechanism. Also by means of the ball screw mechanism, it can be achieved that the rotation of the drive shaft is reliably converted into the translational movement of the actuator element. Preferably, the ball screw mechanism has a nut that is rotatably supported and a threaded spindle that is slidably supported, and the force transmission between the nut and the threaded spindle is provided by a plurality of balls of the ball screw mechanism.

[0007] According to a preferred embodiment, the transmission mechanism device is at least partially arranged within the transmission mechanism housing of the operating device, and the motor housing is adapted to be attached to the transmission mechanism housing. By arranging the transmission mechanism device within the transmission mechanism housing, the transmission mechanism device is protected from external influences by the transmission mechanism housing. Preferably, the actuator element is also at least partially arranged within the transmission mechanism housing. By attaching the motor housing to the transmission mechanism housing, the operating device is integrally formed mechanically robustly. Preferably, the worm transmission mechanism is arranged within the transmission mechanism housing. For this purpose, the drive shaft protrudes from the motor housing, and the threaded thread of the drive shaft penetrates into the transmission mechanism housing such that it is arranged within the transmission mechanism housing. Preferably, the drive shaft penetrates into the transmission mechanism housing through a through-hole in the housing wall of the transmission mechanism housing. Preferably, the spindle transmission mechanism or the ball screw mechanism is at least partially arranged within the transmission mechanism housing. In particular, the motor housing is attached to the transmission mechanism housing by at least one attachment means, for example a screw.

[0008] Preferably, the motor housing is attached to the transmission mechanism housing flange of the transmission mechanism housing. Thereby, on the one hand, a mechanically particularly robust attachment of the motor housing to the transmission mechanism housing can be achieved, for example, by means of the attachment means mentioned above. In addition, by attaching the motor housing to the transmission mechanism housing flange, a fluid seal acting between the motor housing and the transmission mechanism housing can also be provided. Preferably, the motor housing flange of the motor housing abuts the transmission mechanism housing flange for sealing therewith for this purpose.

[0009] Preferably, the transmission mechanism housing is a cylindrical extrusion profile. The extrusion profile can typically be manufactured at low cost, and as a result, by forming the transmission mechanism housing as an extrusion profile, the manufacturing cost of the operating device is further reduced. An element formed in a cylindrical shape has a jacket wall that is at least substantially closed in the circumferential direction, and the jacket wall forms or surrounds an axial through portion of the cylindrical element. Correspondingly, the cylindrical extrusion profile also has this type of jacket wall and this type of axial through portion, and the axial through portion forms the interior of the housing of the extrusion profile. The expression "cylindrical" does not, however, mean a cross-section having a specific shape. Rather, the cross-section of the extrusion profile can exhibit various shapes. Preferably, however, the axial through portion has at least a substantially circular cross-section. Preferably, the extrusion profile is made of aluminum.

[0010] According to a preferred embodiment, it is contemplated that the sliding axis of the actuator element is oriented perpendicular to the cross-section of the extrusion profile. The cross-section of the extrusion profile is a surface having a shape corresponding to the opening of the extrusion die used in the manufacture of the extrusion profile. As previously mentioned, the extrusion profile has an axial through-hole based on forming the extrusion profile into a cylindrical shape. When the sliding axis of the actuator element is oriented perpendicular to the cross-section of the extrusion profile, the extrusion profile opens correspondingly in the sliding direction of the actuator element. This simplifies connecting the actuator element to another element, for example, the master brake cylinder.

[0011] According to a preferred embodiment, it is contemplated that at least one first bearing location of the drive shaft is supported by the transmission housing. Since the drive shaft is supported by the transmission housing, the position of the drive shaft within the transmission housing can be defined particularly precisely. This leads to the fact that the introduction of lateral forces into the worm transmission mechanism can be reduced.

[0012] According to a preferred embodiment, it is provided that the first bearing location is arranged on the side of the screw thread facing away from the rotor. By supporting the drive shaft on the side of the screw thread facing away from the rotor, the introduction of lateral forces into the worm transmission can be particularly effectively avoided. Preferably, the drive shaft has a second bearing location in addition to the first bearing location, which is arranged between the screw thread and the rotor. Particularly preferably, the second bearing location is supported by a bearing shield arranged on the motor housing. Alternatively, preferably, the second bearing location is also supported by the transmission housing. Preferably, the drive shaft has a third bearing location in addition to the first bearing location, which is arranged on the side of the rotor facing away from the screw thread. Particularly preferably, the third bearing location is supported by the bottom of the motor housing. Preferably, the drive shaft has, in addition to the first bearing point, both a second bearing point and a third bearing point, so that there are at least three bearing points in total on the drive shaft, Alternatively, the drive shaft has, in addition to the first bearing point, only the second bearing point or only the third bearing point.

[0013] According to a preferred embodiment, it is provided that the drive shaft has a first end on the side of the screw thread facing away from the rotor, and that a speed sensor is arranged at the first end. The first end is easily accessible for measuring or detecting the speed of the drive shaft, so that arranging the speed sensor at the first end of the drive shaft is preferred. The speed sensor is preferably press-fitted onto the first end. The first bearing point is preferably arranged adjacent to the speed sensor. This achieves a particularly precise measurement of the speed of the drive shaft.

[0014] Preferably, the first end protrudes from the powertrain housing, i.e. the drive shaft passes through the powertrain housing. Since the first end protrudes from the powertrain housing, accessibility of the first end for speed measurement is further improved.

[0015] According to a preferred embodiment, it is contemplated that the first end portion penetrates into the control device of the operating device. Preferably, the control device is formed to determine the rotational speed of the drive shaft according to the sensor signal of the rotational speed sensor. Since the first end portion penetrates into the control device, connecting the rotational speed sensor to the control device by signal technology can be technically easily realized.

[0016] The braking system according to the invention is characterized by the operating device according to the invention according to the features of claim 13. From this, the advantages already mentioned also arise. Further preferred features and combinations of features are evident from the foregoing description and the claims.

[0017] The present invention will be described in detail below with reference to the drawings.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0019] FIG. 1 shows a longitudinal cross-sectional view of an operating device 1 for a braking system 2 of a motor vehicle, not shown in detail. The operating device 1 comprises an actuator element 3 or a thrust element 3 which is slidably supported, and the actuator element 3 or the thrust element 3 is here formed as a push rod 3. The actuator element 3 is slidable in a first direction 5 and a second direction 6 opposite to the first direction 5 along a sliding axis 4. The sliding axis 4 corresponds to the longitudinal central axis of the actuator element 3.

[0020] The actuator element 3 is arranged at least partially within the transmission mechanism housing 7 of the operating device 1. Here, the transmission mechanism housing 7 is a cylindrical extrusion profile 7. In that regard, the transmission mechanism housing 7 has a circumferentially closed jacket wall 8. The jacket wall 8 forms or surrounds an axial through-passage 9 of the transmission mechanism housing 7, and the axial through-passage 9 forms the housing interior 10 of the transmission mechanism housing 7. Here, the axial through-passage 9 has a circular cross-section. The actuator element 3 is arranged within the transmission mechanism housing 7 or the housing interior 10 such that the sliding axis 4 is oriented perpendicular to the cross-section of the transmission mechanism housing 7.

[0021] The main brake cylinder 11 of the operating device 1 is arranged in a housing-fixed manner on the transmission mechanism housing 7. Here, the main brake cylinder 11 is arranged on the first end face 12 of the jacket wall 8. Within the main brake cylinder 11, a first hydraulic piston 13 and a second hydraulic piston 14 are slidably supported, i.e., slidably supported in a first direction 5 and a second direction 6. The main brake cylinder 11 has a plurality of hydraulic ports 15, 16. When the operating device 1 is assembled into the brake system 2 as specified, the hydraulic ports 15, 16 are fluid-technologically connected to the slave cylinders of the friction brake device of the brake system 2. The friction brake device is operable in this case by the sliding of the hydraulic pistons 13 and 14 in the first direction 5. The actuator element 3 is connected to the hydraulic pistons 13 and 14 such that the hydraulic pistons 13 and 14 are slidable in the first direction 5 by the actuator element 3. The friction brake device is thus operable by the sliding of the actuator element 3.

[0022] Furthermore, a housing plate 17 is arranged in a housing-fixed manner on the transmission mechanism housing 7. Here, the housing plate 17 is arranged on the second end face 18 of the jacket wall 8, which faces away from the first end face 12. The housing plate 17 at least partially closes the axial through-passage 9.

[0023] The operating device 1 further includes a drive unit 19. The configuration of the drive unit 19 will be described in detail below with reference to FIG. 2. FIG. 2 shows a cross section of the operating device 1 for this purpose. The drive unit 19 has a motor housing 20, and an electromechanical machine 21 is arranged in the motor housing 20. The ring-shaped rotor 22 of the electromechanical machine 21 is arranged non-rotatably relative to the drive shaft 23, and the drive shaft 23 is rotatably supported about the rotation axis 24. The ring-shaped stator 25 of the electromechanical machine 21 is arranged in the motor housing 20 in a housing-fixed manner and surrounds the rotor 22 in the radial direction with respect to the rotation axis 24. The motor housing 20 is attached to the transmission mechanism housing 7. Here, this is achieved by the motor housing flange 26 of the motor housing 20 being attached to the transmission mechanism housing flange 28 of the transmission mechanism housing 7 by a plurality of attachment means 27.

[0024] The drive shaft 23 is connected to the actuator element 3 by a transmission mechanism device 29 such that the actuator element 3 is slidable by the electromechanical machine 21. FIG. 3 shows a perspective view of the transmission mechanism device 29, and the transmission mechanism housing 7 is omitted in FIG. 3. As can be seen, for example, from FIG. 1, the rotation axis 24 of the drive shaft 23 is oriented perpendicular to the sliding axis 4 of the actuator element 3. This makes it possible to technically simply connect the drive shaft 23 to the actuator element 3 by a transmission mechanism.

[0025] The transmission mechanism device 29 has a worm transmission mechanism 30. The worm transmission mechanism 30 has a worm shaft 31 and a worm wheel 32. The worm shaft 31 is formed by the drive shaft 23, and the drive shaft 23 thus has a threaded screw thread 33. The worm wheel 32 has an external tooth row 34, and the external tooth row 34 meshes with the threaded screw thread 33. The worm transmission mechanism 30 is arranged within the transmission mechanism housing 7. For this purpose, the drive shaft 23 protrudes from the motor housing 20 and enters into the transmission mechanism housing 7 such that the threaded screw thread 33 is arranged within the transmission mechanism housing 7 through the first through portion 35 of the jacket wall 8. The worm wheel 32 is arranged coaxially with respect to the actuator element 3 within the housing interior 10. The axis of rotation of the worm wheel 32 corresponds to, that is, the sliding axis 4 of the actuator element 3.

[0026] The transmission mechanism device 29 further has another transmission mechanism 36, and this another transmission mechanism 36 is formed to convert rotation into a translational movement. According to the embodiment shown in the drawings, this another transmission mechanism 36 is formed as a spindle transmission mechanism 36. FIG. 4 shows a longitudinal sectional view of the operating device 1 in the region of the spindle transmission mechanism 36. According to another embodiment, this another transmission mechanism 36 is formed, for example, as a ball screw mechanism.

[0027] The spindle transmission mechanism 36 has a spindle nut 37 rotatably supported and a threaded spindle 38 slidably supported. The spindle transmission mechanism 36 is also arranged at least partially inside the housing 10. The spindle nut 37 is arranged coaxially with the worm wheel 32 and is rotatable by the worm transmission mechanism 30. According to the embodiment shown in the drawings, the spindle nut 37 and the worm wheel 32 are manufactured integrally with each other. According to another embodiment, the worm wheel 32 is arranged, for example, non-rotatably relative to the spindle nut 37. The threaded spindle 38 is connected to the actuator element 3 such that the actuator element 3 is slidable at least in the first direction 5 by the threaded spindle 38. Here, the threaded spindle 38 is arranged in the axial through-hole 61 of the housing plate 17. A rotation prevention structure 60 is attached to the end of the threaded spindle 38 facing the actuator element 3. The rotation prevention structure 60 interacts with the transmission housing 7 to support the threaded spindle 38.

[0028] The drive shaft 23 has a first end 39 on the side of the screw thread 33 away from the rotor 22. The first end 39 projects from the transmission housing 7 through the second through-hole 40 of the jacket wall 8. A rotational speed sensor 41 is arranged at the first end 39. Here, the rotational speed sensor 41 is press-fitted onto the first end 39. The first end 39 carrying the rotational speed sensor 41 projects into the control device 42 of the operating device 1. The control device 42 is formed to obtain the rotational speed of the drive shaft 23 according to the sensor signal of the rotational speed sensor 41 and to control the operation of the electromechanical machine 21 according to the obtained rotational speed. Since the first end 39 having the rotational speed sensor 41 projects into the control device 42, the sensor signal of the rotational speed sensor 41 can be technically easily supplied to the control device 42.

[0029] The drive shaft 23 has a first bearing point 43, which is arranged on the side of the screw thread 33 facing away from the rotor 22. Here, the bearing point 43 is arranged between the rotational speed sensor 41 and the screw thread 33, adjacent to the rotational speed sensor 41. The first bearing point 43 is supported by the transmission housing 7, which here carries a rotary bearing 44 for this purpose, which acts between the transmission housing 7 and the first bearing point 43 of the drive shaft 23.

[0030] The drive shaft 23 furthermore has a second bearing point 45, which is arranged between the screw thread 33 and the rotor 22. Here, the second bearing point 45 is supported by a bearing shield 46 which is arranged in the motor housing 20. For this purpose, the bearing shield 46 carries a rotary bearing 47 which acts between the drive shaft 23, on the one hand, and the bearing shield 46, on the other hand. According to a further embodiment, the second bearing point 46 is also supported by the transmission housing 7.

[0031] The drive shaft 23 further has a third bearing point 48. The third bearing point 48 is arranged on the side of the rotor 22 facing away from the screw thread 33. Here, the third bearing point 48 is supported by a bottom part 49 of the motor housing 20. The bottom part 49 carries for this purpose a rotary bearing 50 which acts between the bottom part 49 and the drive shaft 23.

[0032] The actuating device 1 further comprises an actuating element 51, which is slidably supported in an axial through-hole 52 of the threaded spindle 38. A first end 53 of the actuating element 51 can be coupled or is coupled to a brake pedal of the brake system 2 by means of an input rod 54, so that the actuating element 51 is in this case slidable by actuation of the brake pedal. A second end 55 of the actuating element 51 is coupled to the actuator element 3 such that the actuator element 3 is slidable by means of the actuating element 51. The friction brake device is thus also actuable by actuation of the brake pedal.

Description of Symbols

[0033] 1 Operating device 2 Brake system 3 Actuator element, thrust element, push rod 4 Sliding axis 5 First direction 6 Second direction 7 Transmission mechanism housing, extrusion profile 8 Jacket wall 9 Axial through-hole 10 Inside the housing 11 Master brake cylinder 12 First end face 13 First hydraulic piston 14 Second hydraulic piston 15 Hydraulic port 16 Hydraulic port 17 Housing plate 18 Second end face 19 Driving unit 20 Motor housing 21 Electromechanical device 22 Rotor 23 Driving shaft 24 Axis of rotation 25 Stator 26 Motor housing flange 27 Mounting means 28 Transmission mechanism housing flange 29 Transmission mechanism device 30 Worm transmission mechanism 31 Worm shaft 32 Worm wheel 33 Threaded screw thread 34 External tooth row 35 First through-hole 36 Another transmission mechanism, spindle transmission mechanism 37 Spindle nut 38 Threaded spindle 39 First end 40 Second through-hole 41 Rotation speed sensor 42 Control device 43 First bearing location 44 Rotational bearing 45 Second bearing location 46 Bearing shield 47 Rotational bearing 48 Third bearing location 49 Bottom part 50 Rotational bearing 51 Operating element 52 Axial through-hole 53 First end 54 Input rod 55 Second end 60 Anti-rotation structure 61 Axial through-hole

Claims

1. An operating device for a braking system, comprising: an electromechanical machine (21) disposed within a motor housing (20), wherein a rotor (22) of the electromechanical machine (21) is disposed non-rotatably relative to a drive shaft (23) that is rotatably supported, and an actuator element (3) slidably supported, wherein the drive shaft (23) is connected to the actuator element (3) by a transmission mechanism device (29) such that the actuator element (3) is slidable by the electromechanical machine (21), the transmission mechanism device (29) having a worm transmission mechanism (30) having a worm shaft (31) and a worm wheel (32), and the drive shaft (23) forming the worm shaft (31), in the operating device, a rotational axis (24) of the drive shaft (23) is oriented perpendicular to a sliding axis (4) of the actuator element (3), characterized in that it is an operating device for a braking system.

2. The operating device according to claim 1, characterized in that the transmission mechanism device (29) has a spindle transmission mechanism (36) that is transmission-mechanically connected downstream of the worm transmission mechanism (30).

3. The operating device according to claim 1, characterized in that the transmission mechanism device (29) has a ball screw mechanism that is transmission-mechanically connected downstream of the worm transmission mechanism (30).

4. The transmission mechanism device (29) is at least partially disposed within a transmission mechanism housing (7) of the operating device (1), and the motor housing (20) is attached to the transmission mechanism housing (7), in particular by means of at least one attachment means (27), characterized in that it is an operating device according to any one of claims 1 to 3.

5. The operating device according to claim 4, characterized in that the motor housing (20) is attached to a transmission mechanism housing flange (28) of the transmission mechanism housing (7).

6. The operating device according to claim 4 or 5, characterized in that the transmission mechanism housing (7) is a cylindrical extrusion profile (7).

7. The operating device according to claim 6, characterized in that the sliding axis (4) of the actuator element (3) is oriented perpendicular to a cross-section of the extrusion profile (7).

8. The operating device according to any one of claims 4 to 7, characterized in that at least one first bearing location (43) of the drive shaft (23) is supported by the transmission housing (7).

9. The drive shaft (23) has a threaded thread (33), and the first bearing location (43) is arranged on the side of the threaded thread (33) facing away from the rotor (22). The operating device according to claim 8, characterized in that.

10. The drive shaft (23) has a first end (39) on the side of the threaded thread (33) facing away from the rotor (22), and a rotational speed sensor (41) is arranged at the first end (39). The operating device according to any one of claims 1 to 9, characterized in that.

11. The operating device according to claim 10, characterized in that the first end (39) projects from the transmission housing (7).

12. The operating device according to claim 10 or 11, characterized in that the first end (39) penetrates into the control device (42) of the operating device (1).

13. A braking system, characterized by the operating device (1) according to any one of claims 1 to 12.

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