Actuating device for brake system, brake system

Abstract

The invention relates to an actuating device (1) for a brake system (2), comprising: an electric motor (21) arranged in a motor housing (20), a rotor (22) of the electric motor (21) being arranged non-rotatably on a rotatably mounted drive shaft (23); the drive shaft (23) is coupled to the actuator element (3) by means of a transmission (29) in such a way that the actuator element (3) can be moved by means of the electric motor (21), the transmission (29) has a worm gear drive (30) having a worm shaft (31) and a worm gear (32), and the drive shaft (23) forms the worm shaft (31). According to the invention, the axis of rotation (24) of the drive shaft (23) is oriented perpendicular to the axis of movement (4) of the actuator element (3).

Description

Technical Field

[0001] The present invention relates to an operating device for a brake system, the operating device comprising: an electric motor arranged in a motor housing, wherein a rotor of the electric motor is arranged non-rotatably on a rotatably supported drive shaft; and a movably supported actuator element, wherein the drive shaft is coupled to the actuator element via a transmission device so that the actuator element can be moved by the motor, wherein the transmission device has a worm gear transmission mechanism with a worm shaft and a worm wheel, and wherein the drive shaft forms the worm shaft.

[0002] Furthermore, the invention relates to a brake system. Background Art

[0003] The hydraulic brake system of a motor vehicle usually has a plurality of friction brake devices. The friction brake device is effectively connected to the operating device of the brake system so that the friction brake device can be operated by the operating device. With the increasing degree of electrification of motor vehicles, the operating device of the brake system is also increasingly electrified. In this regard, it is known that the operating device for the brake system is equipped with an electric motor arranged in a motor housing, wherein the rotor of the electric motor is arranged non-rotatably on a rotatably supported drive shaft. In order to be able to operate the friction brake device by the operating device, the operating device also has a movably supported actuator element. The drive shaft is coupled to the actuator element by a transmission device so that the actuator element can be moved by the motor. The transmission device is also configured to convert the rotation of the drive shaft into a translational movement of the actuator element. Therefore, the friction brake device can be operated by the motor. Here, it is known to use a worm gear mechanism having a worm shaft and a worm wheel in the transmission device. By means of the worm gear mechanism, a high transmission ratio can be achieved. Therefore, the low noise generation of the operating device during operation is achieved by the worm gear mechanism. Usually, the worm shaft is formed by the drive shaft. The drive shaft has a thread because it is formed as a worm shaft. Summary of the invention

[0004] The advantage of the operating device according to the invention having the features of claim 1 is that the operating device can be realized cost-effectively. To this end, it is provided according to the invention that the axis of rotation of the drive shaft is oriented perpendicularly to the axis of movement of the actuator element. By the orientation of the axis of rotation of the drive shaft according to the invention relative to the axis of movement of the actuator element, a simple and mechanically stable coupling of the drive shaft to the actuator element can be achieved in terms of transmission technology. Preferably, the worm wheel is arranged coaxially with the actuator element so that the longitudinal center axis of the worm wheel corresponds to the axis of movement of the actuator element. The advantage of this embodiment of the operating device is that the operating device is compact and thus saves structural space. Preferably, the thread of the drive shaft meshes with the external toothing of the worm wheel.

[0005] According to a preferred embodiment, the transmission device has a spindle drive which is located downstream of the worm gear in terms of transmission technology. The spindle drive can reliably convert the rotation of the drive shaft into a translational movement of the actuator element. In addition, the use of the spindle drive is associated with low manufacturing costs. Preferably, the spindle drive has a rotatably supported spindle nut and a movably supported threaded spindle. Preferably, the spindle nut forms a worm wheel. As an alternative, the worm wheel is preferably arranged on the spindle nut in a rotationally fixed manner. Preferably, the threaded spindle forms the actuator element. As an alternative, the threaded spindle is preferably coupled to the actuator element so that the actuator element can be moved by the threaded spindle.

[0006] According to an alternative embodiment, it is preferably provided that the transmission has a ball screw drive which is located downstream of the worm gear in terms of transmission technology. The ball screw drive can also achieve a reliable conversion of the rotation of the drive shaft into a translational movement of the actuator element. Preferably, the ball screw drive has a rotatably mounted nut and a movably mounted threaded spindle, wherein the force transmission between the nut and the threaded spindle is provided by a plurality of balls of the ball screw drive.

[0007] According to a preferred embodiment, the transmission is at least partially arranged in the transmission housing of the operating device, and the motor housing is fixed to the transmission housing. By arranging the transmission in the transmission housing, the transmission is protected by the transmission housing from external influences. Preferably, the actuator element is at least partially arranged in the transmission housing. By fixing the motor housing to the transmission housing, the operating device as a whole is mechanically stable. Preferably, the worm gear mechanism is arranged in the transmission housing. For this purpose, the drive shaft protrudes from the motor housing and enters the transmission housing, so that the thread of the drive shaft is arranged in the transmission housing. Preferably, the drive shaft protrudes into the transmission housing through the penetration of the housing wall of the transmission housing. Preferably, the spindle transmission or the ball screw transmission is at least partially arranged in the transmission housing. The motor housing is fixed to the transmission housing in particular by at least one fastening device, such as a screw.

[0008] Preferably, the motor housing is fastened to the transmission housing flange of the transmission housing. This allows, on the one hand, a particularly mechanically stable fastening of the motor housing to the transmission housing, for example by means of the above-mentioned fastening means. In addition, by fastening the motor housing to the transmission housing flange, a fluid seal can also be provided which acts between the motor housing and the transmission housing. Preferably, the motor housing flange of the motor housing bears sealingly against the transmission housing flange for this purpose.

[0009] Preferably, the transmission housing is a cylindrical extruded profile. Extruded profiles can generally be manufactured cost-effectively, so that by constructing the transmission housing as an extruded profile, the manufacturing costs of the operating device are also reduced. The element of the cylindrical construction has a side wall that is essentially closed at least in the circumferential direction, wherein the side wall forms or surrounds an axial penetration of the cylindrical element. Therefore, the cylindrical extruded profile also has such a side wall and such an axial penetration, wherein the axial penetration forms the interior of the housing of the extruded profile. However, the term "cylindrical" does not mean that the cross section has a specific shape. On the contrary, the cross section of the extruded profile may have different shapes. Preferably, however, the axial penetration has a cross section that is at least essentially circular. Preferably, the extruded profile is made of aluminum.

[0010] According to a preferred embodiment, the displacement axis of the actuator element is oriented perpendicularly to the cross section of the extruded profile. The cross section of the extruded profile is a surface whose shape corresponds to the opening of the extrusion tool used to produce the extruded profile. As mentioned above, the extruded profile has an axial penetration due to its cylindrical configuration. If the displacement axis of the actuator element is oriented perpendicularly to the cross section of the extruded profile, the extruded profile is correspondingly open in the displacement direction of the actuator element. This simplifies the coupling of the actuator element to another element, such as the master brake cylinder.

[0011] According to a preferred embodiment, at least one first bearing point 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 in the transmission housing can be defined particularly accurately. This has the effect that the introduction of transverse forces into the worm gear can be reduced.

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

[0013] According to a preferred embodiment, the drive shaft has a first end on the side of the thread facing away from the rotor, and the rotational speed sensor is arranged at the first end. The first end is easily accessible for measuring or detecting the rotational speed of the drive shaft, so it is preferred to arrange the rotational speed sensor at the first end of the drive shaft. Preferably, the rotational speed sensor is pressed onto the first end. Preferably, the first bearing point is arranged adjacent to the rotational speed sensor. This enables a particularly accurate measurement of the rotational speed of the drive shaft.

[0014] Preferably, the first end protrudes from the transmission housing. The drive shaft also protrudes through the transmission housing. Since the first end protrudes from the transmission housing, the accessibility of the first end for speed measurement is also improved.

[0015] According to a preferred embodiment, the first end protrudes into a controller of the operating device. Preferably, the controller is designed to determine the rotational speed of the drive shaft based on the sensor signal of the rotational speed sensor. Since the first end protrudes into the controller, the signal connection between the rotational speed sensor and the controller can be easily achieved.

[0016] The brake system according to the invention having the features of claim 13 is characterized by the actuating device according to the invention. This also brings about the advantages already mentioned above. Further preferred features and feature combinations result from the above and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be explained in more detail below with reference to the accompanying drawings, wherein:

[0018] Figure 1 A cross-sectional view showing an operating device for a brake system;

[0019] Figure 2 Another cross-sectional view of the operating device is shown;

[0020] Figure 3 a perspective view showing a transmission of a manipulator; and

[0021] Figure 4 A sectional view of a main shaft transmission mechanism of a transmission is shown. DETAILED DESCRIPTION

[0022] Figure 1 The longitudinal section through an actuating device 1 of a brake system 2 of a motor vehicle (not shown in detail) is shown. The actuating device 1 has a movably mounted actuator element 3 or pressure element 3, which in the present case is designed as a pressure rod 3. The actuator element 3 can be moved along a displacement axis 4 in a first direction 5 and in a second direction 6 opposite to the first direction 5. The displacement axis 4 corresponds to the longitudinal center axis of the actuator element 3.

[0023] The actuator element 3 is arranged at least partially in a transmission housing 7 of the actuating device 1. In the present case, the transmission housing 7 is a cylindrical extruded profile 7. In this respect, the transmission housing 7 has a side wall 8 which is closed in the circumferential direction. The side wall 8 forms or surrounds an axial penetration 9 of the transmission housing 7, wherein the axial penetration 9 forms a housing interior 10 of the transmission housing 7. In the present case, the axial penetration 9 has a circular cross section. The actuator element 3 is arranged in the transmission housing 7, more precisely in the housing interior 10, so that the displacement axis 4 is oriented perpendicular to the cross section of the transmission housing 7.

[0024] A master brake cylinder 11 of the actuating device 1 is arranged fixedly relative to the transmission housing 7. In the present case, the master brake cylinder 11 is arranged at a first end side 12 of the side wall 8. A first hydraulic piston 13 and a second hydraulic piston 14 are supported in the master brake cylinder 11 so as to be movable, i.e., movable in a first direction 5 and a second direction 6. The master brake cylinder 11 has a plurality of hydraulic connections 15, 16. If the actuating device 1 is installed as intended in the brake system 2, the hydraulic connections 15, 16 are fluidically connected to the slave cylinders of the friction brake device of the brake system 2. In this case, the friction brake device can be actuated by moving the hydraulic pistons 13 and 14 in the first direction 5. The actuator element 3 is coupled to the hydraulic pistons 13 and 14 so that the hydraulic pistons 13 and 14 can be moved in the first direction 5 by the actuator element 3. Thus, the friction brake device can be actuated by moving the actuator element 3.

[0025] A housing plate 17 is also arranged fixedly relative to the transmission housing 7. In the present case, the housing plate 17 is arranged at a second end face 18 of the side wall 8 facing away from the first end face 12. The housing plate 17 at least partially closes the axial penetration 9.

[0026] The operating device 1 also has a drive unit 19. Figure 2 The embodiment of the drive unit 19 is explained in more detail. Figure 2 For this purpose, a cross section of the operating device 1 is shown. The drive unit 19 has a motor housing 20 in which an electric motor 21 is arranged. An annular rotor 22 of the electric motor 21 is arranged on a drive shaft 23 in a rotationally fixed manner, wherein the drive shaft 23 is supported rotatably about an axis of rotation 24. An annular stator 25 of the electric motor 21 is arranged fixedly on the motor housing 20 relative to the housing and radially surrounds the rotor 22 with reference to the axis of rotation 24. The motor housing 20 is fixed to the transmission housing 7. In the present case, this is achieved by fixing a motor housing flange 26 of the motor housing 20 to a transmission housing flange 28 of the transmission housing 7 by means of a plurality of fastening means 27.

[0027] The drive shaft 23 is coupled to the actuator element 3 via a transmission 29 , so that the actuator element 3 can be moved by the electric motor 21 . Figure 3 A perspective view of the transmission device 29 is shown, wherein the Figure 3 The transmission mechanism housing 7 in the embodiment. For example, Figure 1 As shown, the rotation axis 24 of the drive shaft 23 is oriented perpendicularly to the displacement axis 4 of the actuator element 3. This allows a simple coupling of the drive shaft 23 to the actuator element 3 in terms of transmission technology.

[0028] The gearing 29 has a worm gear 30. The worm gear 30 has a worm shaft 31 and a worm wheel 32. The worm shaft 31 is formed by the drive shaft 23, wherein the drive shaft 23 has a thread 33 for this purpose. The worm wheel 32 has an external toothing 34, which meshes with the thread 33. The worm gear 30 is arranged in the gear housing 7. For this purpose, the drive shaft 23 protrudes from the motor housing 20 and enters the gear housing 7 through a first penetration 35 of the side wall 8, so that the thread 33 is arranged in the gear housing 7. The worm wheel 32 is arranged coaxially with the actuator element 3 in the housing interior 10. The axis of rotation of the worm wheel 32 thus corresponds to the displacement axis 4 of the actuator element 3.

[0029] The transmission device 29 also has a further transmission mechanism 36 which is designed to convert a rotation into a translational movement. According to the embodiment shown in the figures, the further transmission mechanism 36 is designed as a spindle transmission mechanism 36 . Figure 4 The longitudinal section through the actuating device 1 is shown in the region of the spindle drive 36. According to a further embodiment, the further drive 36 is designed, for example, as a ball screw drive.

[0030] The spindle drive 36 has a rotatably mounted spindle nut 37 and a movably mounted threaded spindle 38. Furthermore, the spindle drive 36 is arranged at least partially in the housing interior 10. The spindle nut 37 is arranged coaxially with the worm wheel 32 and can be rotated by the worm gear drive 30. According to the embodiment shown in the figures, the spindle nut 37 and the worm wheel 32 are made integrally with each other. According to another embodiment, the worm wheel 32 is arranged on the spindle nut 37, for example, in a rotationally fixed manner. The threaded spindle 38 is coupled to the actuator element 3 so that the actuator element 3 can be moved at least in the first direction 5 by the threaded spindle 38. In the present case, the threaded spindle 38 is arranged in an axial penetration 61 of the housing plate 17. The anti-rotation structure 60 is fixed to the end of the threaded spindle 38 facing the actuator element 3. The anti-rotation structure 60 interacts with the gear housing 7 to support the threaded spindle 38.

[0031] The drive shaft 23 has a first end 39 on the side of the thread 33 facing away from the rotor 22. The first end 39 protrudes from the transmission housing 7 through a second penetration 40 of the side wall 8. A rotation speed sensor 41 is arranged at the first end 39. In the present case, the rotation speed sensor 41 is pressed onto the first end 39. The first end 39 carrying the rotation speed sensor 41 protrudes into a controller 42 of the operating device 1. The controller 42 is designed to determine the rotation speed of the drive shaft 23 based on the sensor signal of the rotation speed sensor 41 and to control the motor 21 based on the determined rotation speed. Since the first end 39 with the rotation speed sensor 41 protrudes into the controller 42, the sensor signal of the rotation speed sensor 41 is technically easy to be supplied to the controller 42.

[0032] The drive shaft 23 has a first bearing point 43. The first bearing point 43 is arranged on the side of the thread 33 facing away from the rotor 22. In the present case, the bearing point 43 is arranged between the rotational speed sensor 41 and the thread 33 adjacent to the rotational speed sensor 41. The first bearing point 43 is supported by the transmission housing 7. In the present case, the transmission housing 7 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.

[0033] The drive shaft 23 also has a second bearing point 45. The second bearing point 45 is arranged between the thread 33 and the rotor 22. In the present case, the second bearing point 45 is supported by a bearing plate 46 arranged on the motor housing 20. For this purpose, the bearing plate 46 carries a rotary bearing 47, which acts between the drive shaft 23 on one side and the bearing plate 46 on the other side. According to another embodiment, the second bearing point 46 is also supported by the transmission housing 7.

[0034] The drive shaft 23 also has a third bearing point 48. The third bearing point 48 is arranged on the side of the rotor 22 facing away from the thread 33. In the present case, the third bearing point 48 is supported by a bottom 49 of the motor housing 20. For this purpose, the bottom 49 carries a rotary bearing 50, which acts between the bottom 49 and the drive shaft 23.

[0035] The actuating device 1 further comprises an actuating element 51 which is movably supported in an axial penetration 52 of the threaded spindle 38. A first end 53 of the actuating element 51 is coupled / can be coupled to a brake pedal of the brake system 2 via an input rod 54, so that the actuating element 51 can be moved by actuating the brake pedal. A second end 55 of the actuating element 51 is coupled to the actuator element 3, so that the actuator element 3 can be moved by the actuating element 51. Thus, the friction brake device can also be actuated by actuating the brake pedal.

Claims

1. An operating device for a brake system, the operating device comprising: An electric motor (21) is arranged in a motor housing (20), wherein: The rotor (22) of the electric motor (21) is arranged in a rotationally fixed manner on a rotatably supported drive shaft (23); as well as A movably mounted actuator element (3), wherein the drive shaft (23) is coupled to the actuator element (3) via a transmission (29) such that the actuator element (3) can be moved by the motor (21), wherein the transmission (29) has a worm gear (30) with a worm shaft (31) and a worm wheel (32), and wherein the drive shaft (23) forms the worm shaft (31). It is characterized in that the rotation axis (24) of the drive shaft (23) is oriented perpendicularly to the displacement axis (4) of the actuator element (3).

2. The operating device according to claim 1, characterized in that The transmission (29) has a spindle drive (36) which is located downstream of the worm gear (30) in terms of drive technology.

3. The operating device according to claim 1, characterized in that The transmission (29) has a ball screw drive which is located downstream of the worm gear (30) in terms of transmission technology.

4. An operating device according to any one of the preceding claims, characterized in that The transmission (29) is at least partially arranged in a transmission housing (7) of the operating device (1), and the motor housing (20) is fastened to the transmission housing (7), in particular by at least one fastening means (27).

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

6. The operating device according to any one of claims 4 and 5, characterized in that The transmission mechanism housing (7) is a cylindrical extruded profile (7).

7. The operating device according to claim 6, characterized in that The displacement axis (4) of the actuator element (3) is oriented perpendicularly to the cross section of the extruded profile (7).

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

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

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

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

12. The operating device according to any one of claims 10 and 11, characterized in that The first end (39) protrudes into a control (42) of the operating device (1).

13. A braking system, characterized in that: An actuating device (1) according to any of the preceding claims is provided.

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