Drive unit for an operating device of a braking system, operating device for a braking system, braking system

Abstract

The present invention relates to a drive unit (13) for an operating device (1) of a braking system (2), comprising a motor housing (14) and an electromechanical machine (15) arranged in the motor housing (14), wherein a rotor (19) of the electromechanical machine (15) is non-rotatably arranged on a motor shaft (20) rotatably supported in the motor housing (14), the electromechanical machine (15), and a planetary gear mechanism (23) for coupling or coupling the motor shaft (20) to an actuator element (3) of the operating device (1), the planetary gear mechanism (23) having a planet carrier (25) rotatably supported, the planet carrier (25) having a driven shaft (27) and a carrier part (26), and at least one planetary gear (33) being rotatably supported on the carrier part. The driven shaft (27) and the carrier part (26) are intended to be manufactured separately from each other and non-rotatably coupled to each other.

Description

Technical Field

[0001] The present invention relates to a drive unit for an operating device of a braking system, comprising a motor housing, an electromechanical device disposed within the motor housing, wherein a rotor of the electromechanical device is non-rotatably disposed on a motor shaft rotatably supported within the motor housing, and a planetary gear mechanism coupling or coupling the motor shaft to an actuator element of the operating device. The planetary gear mechanism has a planet carrier rotatably supported, the planet carrier has a driven shaft and a carrier portion, and at least one planetary gear is rotatably supported on the carrier portion.

[0002] Furthermore, the present invention relates to an operating device for a braking system, comprising an actuator element and a drive unit for driving the actuator element.

[0003] Furthermore, the present invention relates to a braking system.

Background Art

[0004] Drive units of the type initially mentioned are known from the prior art. With the increasing electrification of motor vehicles, the electrification of operating devices for braking systems is also increasing. For this reason, the operating device has a drive unit with an electromechanical device disposed within a motor housing. In this case, the rotor of the electromechanical device is non-rotatably disposed on a motor shaft rotatably supported within the motor housing. To achieve high torque, a planetary gear mechanism is often connected downstream of the motor shaft, so that the motor shaft can be coupled or is coupled to an actuator element of the operating device by the planetary gear mechanism. In this case, the planetary gear mechanism typically has a planet carrier rotatably supported, which has a driven shaft and a carrier portion, and at least one planetary gear is rotatably supported on the carrier portion. In drive units known prior to the present application, the driven shaft and the carrier portion are typically integrally formed with each other.

Summary of the Invention

[0005] The drive unit according to the present invention having the constituent elements of claim 1 has the advantage that the manufacturing cost for the drive unit is low. For this reason, according to the present invention, it is contemplated that the driven shaft and the carrier part are manufactured separately from each other and are coupled to be non-rotatable relative to each other. Generally, the planetary carrier has a relatively complex geometric shape for the carrier part and the driven shaft, and therefore, the integral manufacture of the planetary carrier involves high costs. By manufacturing the driven shaft and the carrier part separately, the manufacturing cost can be reduced. This is obtained in particular because manufacturing the carrier part and the driven shaft separately enables the use of a technically simpler manufacturing method. In addition, the carrier part and the driven shaft can be easily manufactured from different materials for separate manufacture. That is, for the carrier part and the driven shaft, materials particularly suitable for each component can be selected respectively. Preferably, the carrier part and the driven shaft are manufactured from different materials.

[0006] Preferably, the carrier part is made of plastic. Thereby, the manufacturing cost for the carrier part can be further reduced. In addition, when made of plastic, the carrier part has only a small mass.

[0007] According to an advantageous embodiment, it is contemplated that the driven shaft is made of a metallic material. Thereby, the driven shaft is particularly suitable for transmitting high torque. Particularly preferably, the driven shaft is made of steel or aluminum.

[0008] According to an advantageous embodiment, it is contemplated that the driven shaft and / or the carrier part are produced by extrusion. By extrusion, the driven shaft and the carrier part can be manufactured cost - effectively and with a high throughput. In this case, since the driven shaft and the carrier part are manufactured separately from each other, a mold is also feasible, but the mold may require post - processing of the planetary carrier during the integral manufacture of the planetary carrier by extrusion.

[0009] Preferably, the driven shaft and the carrier part are non - rotatably coupled to each other by a form - locking joint. With a form - locking joint, high torque can also be reliably transmitted. In addition, the structure required to form the form - locking joint can be realized at least substantially without additional cost, especially when manufacturing the carrier part and the driven shaft by extrusion. According to an alternative embodiment, the driven shaft and the carrier part are non - rotatably coupled to each other, for example, by press - fitting or by adhesive bonding.

[0010] According to an advantageous embodiment, it is contemplated that the carrier part has an axial undercut and that the end region of the driven shaft is inserted into the axial undercut for the formation of the form - locking joint. Implementing the planetary carrier in this way makes it technically easy to realize the form - locking joint. For this purpose, preferably, the side wall of the carrier part that forms the axial undercut has a structure that cooperates with the structure of the end region of the driven shaft for the formation of the form - locking joint. Preferably, the axial undercut is formed as an axially penetrating part. This embodiment can be realized particularly easily technically. Alternatively, the axial undercut is formed, for example, as an axial recess with a bottom.

[0011] According to an advantageous embodiment, it is contemplated that the side wall of the carrier part, which forms the axial extraction part, has internal teeth that mesh with the external teeth of the inserted end region for the formation of a shape-locking connection. Such an embodiment of the shape-locking connection is mechanically particularly robust, which is advantageous with regard to the transmission of high torques.

[0012] Preferably, the driven shaft has a first support site and a second support site arranged at a distance from the first support site, where the first support site is arranged between the carrier part and the second support site. By providing two support sites positioned at a distance from each other, precise support of the planetary carrier can be achieved. Since the support sites are formed on the driven shaft, i.e., on an axially shaped element, a pivot bearing with a relatively small diameter can be used to support the planetary carrier. This has a favorable impact on the manufacturing costs of the drive unit. Preferably, the driven shaft has a driven tooth part between these support sites.

[0013] Preferably, the diameter of the first support site is smaller than the diameter of the part of the driven shaft arranged between the plurality of support sites. As described above, in this case, a pivot bearing with a small diameter can be used to support the support site, so a small diameter or a short radial extension is advantageous for the support site. Since the driven shaft and the carrier part are manufactured separately from each other, during the assembly of the drive unit, first, the pivot bearing can be slid onto and attached to the first support site. Only then can the driven shaft be non-rotatably connected to the carrier part. If the planetary carrier is configured integrally, a first support site with a diameter smaller than the diameter of the part arranged between the plurality of support sites is not purposeful. Therefore, it is obvious that the part may interfere with sliding the pivot bearing onto and attaching it to the first support site.

[0014] Preferably, the carrier part is formed in a plate shape. By this, the carrier part has high rigidity, and as a result, it is possible to transmit high torque with at least substantially no deformation of the carrier part.

[0015] Preferably, the carrier part has at least one planet shaft integrally formed with the carrier part. By forming the planet shaft integrally with the carrier part, the number of separate individual parts is reduced. In addition, forming the planet shaft integrally with the carrier part can be technically easily achieved, particularly by extrusion molding.

[0016] According to an advantageous embodiment, it is contemplated that the carrier part is arranged within the motor housing and the driven shaft projects from the motor housing. By arranging the carrier part within the motor housing, the drive unit is formed in a compact manner, saving configuration space. Since the driven shaft projects from the motor housing, it is technically easily possible to connect the driven shaft to a transmission element that is technically downstream in the transmission.

[0017] The operating device according to the invention is characterized in that, according to the features of claim 13, the drive unit is configured according to the invention. Thus, the advantages already mentioned can be obtained. Further advantageous features and combinations of features are apparent from the foregoing description and the claims.

[0018] The braking system according to the invention is characterized in that, according to the features of claim 14, the operating device according to the invention is provided. Thus, the advantages already mentioned can be obtained. Further advantageous features and combinations of features are apparent from the foregoing description and the claims.

[0019] Next, the present invention will be described in more detail based on the drawings.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Embodiment for Carrying Out the Invention

[0021] FIG. 1 is a cross-sectional view of an operating device 1 for an automobile brake system 2 not shown in detail.

[0022] The operating device 1 has a pressure element 3 or an actuator element 3 that is displaceably supported and is formed as a pressure rod 3 in the present embodiment. The actuator element 3 is displaceable in a first direction 4 and in a second direction 5 opposite to the first direction 4. The actuator element 3 is at least partially arranged within a housing 6 of the operating device 1. A brake master cylinder 7 of the operating device 1 is fixedly arranged in the housing. In the brake master cylinder 7, a first hydraulic piston 8 and a second hydraulic piston 9 are supported so as to be displaceable, that is, supported so as to be displaceable in the first direction 4 and in the second direction 5. The brake master cylinder 7 has a plurality of hydraulic connection parts 10, 11. If the operating device 1 is installed in the brake system 2 as specified, the hydraulic connection parts 10, 11 are fluid-technologically connected to a slave cylinder of a friction brake device of the brake system 2. At this time, the friction brake device is operable by the displacement of the hydraulic pistons 8 and 9 in the first direction 4. The actuator element 3 is connected to the hydraulic pistons 8 and 9 such that the hydraulic pistons 8 and 9 can be displaced in the first direction 4 by the actuator element 3. That is, the friction brake device is operable by the displacement of the actuator element 3.

[0023] The operating device 1 further has a transmission housing 12. The housing 6 and the transmission housing 12 are fixed to each other. In the present embodiment, the transmission housing 12 is formed in a shell shape.

[0024] The operating device 1 further has a drive unit 13. The drive unit 13 has a motor housing 14, and an electromechanical machine 15 is disposed within the motor housing. The motor housing 14 is fixed to the transmission housing 12. In the present embodiment, the mounting surface of the motor housing flange 16 of the motor housing 14 is in planar contact with the mounting surface of the transmission housing flange 17 of the transmission housing 12. The stator 18 of the electromechanical machine 15 is fixedly disposed within the housing in the motor housing 14. The rotor 19 of the electromechanical machine 15 is disposed non-rotatably relative to the motor shaft 20. The motor shaft 20 is rotatably supported within the motor housing 14 about the axis of rotation 21.

[0025] The motor shaft 20 is connected to the actuator element 3 by a transmission 22 such that the actuator element 3 can be displaced by the electromechanical machine 15. The transmission 22 has a planetary gear mechanism 23, and the planetary gear mechanism can be driven or rotated by the motor shaft 20. For this reason, the sun gear 24 of the planetary gear mechanism 23 is disposed non-rotatably relative to the motor shaft 20. The planetary gear mechanism 23 has a planet carrier 25 that is rotatably supported. At this time, the axis of rotation of the planet carrier 25 corresponds to the axis of rotation 21 of the motor shaft 20. Next, the embodiment of the planet carrier 25 will be described in detail with reference to FIG. 2. For this reason, FIG. 2 shows a perspective view of the planet carrier 25.

[0026] The planet carrier 25 has a carrier portion 26 and a driven shaft 27. The driven shaft 27 and the carrier portion 26 are manufactured separately from each other and are coupled non-rotatably relative to each other. That is, the planet carrier 25 is formed from a plurality of parts. In the present embodiment, the carrier portion 26 and the driven shaft 27 are each produced by extrusion molding. Preferably, the carrier portion 26 is made of plastic. The driven shaft 27 is preferably made of a metallic material, for example, steel or aluminum.

[0027] The driven shaft 27 is a longitudinally elongated component or a shaft-shaped component. The driven shaft 27 has a first support portion 28 and a second support portion 29. Using the support portions 28 and 29, the planetary carrier 25 can be supported or is supported. At this time, the first support portion 28 is disposed adjacent to the carrier portion 26. The second support portion 29 is axially spaced from the first support portion 28 with respect to the rotational axis 21 of the motor shaft 20 or the planetary carrier 25. The diameters of the support portions 28 and 29 are smaller than the diameter of the portion 30 of the driven shaft 27 between the support portions 28 and 29. The portion 30 between the support portions 28 and 29 has a driven tooth portion 31.

[0028] The carrier portion 26 is formed in a plate shape. The carrier portion 26 has a plurality of planetary shafts 32 formed integrally with the carrier portion 26. As shown in FIG. 1, when the planetary carrier 25 is mounted in the drive unit 13 or the operating device 1, a plurality of planetary gears 33 are rotatably supported by the planetary shafts 32 on the carrier portion 26. The carrier portion 26 has a radially recessed portion 34 between two planetary shafts 32 arranged one after another in the circumferential direction of the carrier portion 26. The radially recessed portion 34 reduces the mass of the carrier portion 26.

[0029] According to the embodiment of the planetary carrier 25 shown in FIG. 2, the driven shaft 27 is non-rotatably coupled to the carrier portion 26 by a shape-constrained coupling portion 35. In this embodiment, the carrier portion 26 has a central axially penetrating portion 36 provided with internal teeth 37. The end region 38 of the driven shaft 27 is inserted into the axially penetrating portion 36. For the formation of the shape-constrained coupling portion 35, the end region 38 has external teeth 39 that mesh with the internal teeth 37 of the axially penetrating portion 36. However, instead of the external teeth 39 and the internal teeth 37, the shape-constrained coupling portion 35 may be formed by the end region 38 and the axially penetrating portion 36 having cross-sections other than circular.

[0030] As is apparent from FIG. 1, the carrier portion 26 is disposed within the motor housing 14. The driven shaft 27 projects axially from the motor housing 14. The planet carrier 25 is rotatably supported by supporting the support portions 28 and 29 of the driven shaft 27. For this reason, the drive unit 13 has a housing-fixed support shield 40 that supports the first support portion 28. The support shield 40 has a sleeve-shaped support portion 41 that radially surrounds the first support portion 28. In the present embodiment, the support portion 41 bears a rolling bearing 42 that acts between the support portion 41 and the first support portion 28. The support shield 40 further has a sleeve-shaped fixing portion 43. The fixing portion 43 abuts against the side wall 44 of the motor housing 14 from the radially inner side. In the present embodiment, the support shield 40 is press-fitted into the motor housing 14. The second support portion 29 of the driven shaft 27 is rotatably supported by the transmission housing 12. For this reason, in the present embodiment, the transmission housing 12 has an axially penetrating portion 45, and the driven shaft 27 axially penetrates and projects through this axially penetrating portion. The inner surface 46 of the transmission housing 12 that forms the axially penetrating portion 45 bears a rolling bearing 47 that acts between the transmission housing 12 and the second support portion 29 of the driven shaft 27. The gear 52 is disposed on the driven shaft 27 in a non-rotatable relative manner between the support portions 28 and 29. In the present embodiment, the gear 52 has internal teeth that are not visible, and these internal teeth mesh with the driven tooth portion 31 of the portion 30 of the driven shaft 27 for non-rotatable connection with the driven shaft 27.

[0031] The planetary gear mechanism 23 further has an internally toothed gear 48 fixed to the housing. The planetary gear 33 meshes with the sun gear 24 on one hand and with the internally toothed gear 48 on the other hand. The outer surface 49 of the side wall of the internally toothed gear 48 abuts against the fixing portion 43 of the support shield 40 from the radially inner side. That is, the support shield 40 bears the internally toothed gear 48.

[0032] In this embodiment, the diameter of the internal gear 48 is larger than the diameter of the electromechanical machine 15. As a result, a planetary gear mechanism 23 with a large gear ratio can be realized. The motor housing 14 is formed in a stepped shape, and thus is adapted to the sizes of the electromechanical machine 15 and the internal gear 48. For this reason, the motor housing 14 has a first axially directed portion 50 assigned to the electromechanical machine 15 and a second axially directed portion 51 assigned to the planetary gear mechanism 23, and in this case the diameter of the first axially directed portion 50 is smaller than the diameter of the second axially directed portion 51.

[0033] The transmission device 22 further has a spindle transmission mechanism 53 with a spindle nut 54 rotatably supported. At this time, the axis of rotation 55 of the spindle nut 54 corresponds to the longitudinal central axis of the actuator element 3. Also, the axis of rotation 55 of the spindle nut 54 is oriented parallel to the axis of rotation 21 of the motor shaft 20. Further, the spindle transmission mechanism 53 has a displaceable lead screw 56. The lead screw 56 is displaceable by the rotation of the spindle nut 54, that is, displaceable in a first direction 4 and a second direction 5. At this time, the lead screw 56 is connected to the actuator element 3 such that the actuator element 3 is displaceable at least in the first direction 4 by the lead screw 56. The spindle transmission mechanism 53 is arranged in an axially penetrating portion 57 of the transmission housing 12.

[0034] The transmission device 22 further has a further gear 58. The further gear 58 is arranged non-rotatably relative to the spindle nut 54. The driven tooth portion 59 of the gear 52 meshes with the driving tooth portion 60 of the further gear 58. That is, the further gear 58 is rotatable by the rotation of the gear 52. Correspondingly, the spindle transmission mechanism 53 is drivable or rotatable by the electromechanical machine 15.

[0035] The motor shaft 20 is supported on the side facing the planetary gear mechanism 23 of the electromechanical machine 15 by a further support shield 61 fixed to the housing. The carrier portion 26 of the planetary carrier 25 is disposed between the support shield 40 and the further support shield 61. The further support shield 61 has a sleeve-shaped support portion 62, and the sleeve-shaped support portion surrounds the motor shaft 20 in the radial direction and supports the motor shaft 20. In the present embodiment, the support portion 62 of the further support shield 61 bears a rolling bearing 63 acting between the support portion 62 and the motor shaft 20. In the present embodiment, the further support shield 61 is press-fitted into the motor housing 14. That is, the further support shield 61 is fixed to the motor housing 14 by a press fit acting between the further support shield 61 and the side wall 44 of the motor housing 14. On the side of the electromechanical machine 15 opposite to the planetary gear mechanism 23, the motor shaft 20 is supported by the bottom 64 of the motor housing 14. For this reason, the bottom 64 has a sleeve-shaped support portion 65 surrounding the motor shaft 20 in the radial direction.

[0036] In the present embodiment, the support portion 65 bears a rolling bearing 66 acting between the support portion 65 and the motor shaft 20.

[0037] The operating device 1 further has a controller 67 formed to drive and control the electromechanical machine 15. The controller 67 is disposed in the housing 6 on the side of the electromechanical machine 15 opposite to the planetary gear mechanism 23.

[0038] The operating device 1 further has an operating element 68 supported displaceably within the axial through portion 69 of the screw spindle 56. The first end portion 70 of the operating element 68 can be connected or is connected by an input rod 71 to the brake pedal of the brake system 2, and as a result, the operating element 68 is displaceable at this time by the operation of the brake pedal. The second end portion 72 of the operating element 68 is connected to the actuator element 3 such that the actuator element 3 is displaceable by the operating element 68. That is, the friction brake device can also be operated by the operation of the brake pedal.

Description of Symbols

[0039] 1 Operating device 2 Brake system 3 Actuator element 13 Driving unit 14 Motor housing 15 Electromechanical 19 Rotor 20 Motor shaft 23 Planetary gear mechanism 25 Planet carrier 26 Carrier part 27 Driven shaft 28 First support part of the driven shaft 29 Second support part of the driven shaft 30 Part of the driven shaft 32 Planet shaft 33 Planet gear 35 Shape-restraining coupling part 36 Axial through-hole (axial extraction hole) 37 Internal teeth 38 End region of the driven shaft 39 External teeth

Claims

1. A drive unit for an operating device of a braking system, comprising a motor housing (14), an electromechanical machine (15) disposed within the motor housing (14), wherein a rotor (19) of the electromechanical machine (15) is non-rotatably disposed on a motor shaft (20) rotatably supported within the motor housing (14), and a planetary gear mechanism (23) for coupling or coupling the motor shaft (20) to an actuator element (3) of the operating device (1), the planetary gear mechanism (23) having a planet carrier (25) rotatably supported, the planet carrier (25) having a driven shaft (27) and a carrier portion (26), and at least one planetary gear (33) rotatably supported on the carrier portion, in the drive unit, the driven shaft (27) and the carrier portion (26) are manufactured separately from each other and are non-rotatably coupled to each other.

2. The drive unit according to claim 1, characterized in that the carrier portion (26) is made of plastic.

3. The drive unit according to any one of claims 1 to 2, characterized in that the driven shaft (27) is made of a metallic material.

4. The drive unit according to any one of claims 1 to 3, characterized in that the driven shaft (27) and / or the carrier portion (28) are made by extrusion molding.

5. The drive unit according to any one of claims 1 to 4, characterized in that the driven shaft (27) and the carrier portion (26) are non-rotatably coupled to each other by a form-fitting joint (35).

6. The drive unit according to claim 5, characterized in that the carrier portion (26) has an axial recess (36), and an end region (38) of the driven shaft (27) is inserted into the axial recess (36) for forming the form-fitting joint (35).

7. The drive unit according to claim 6, characterized in that a side wall of the carrier part (26) forming the axially withdrawn part (36) meshes with an internal tooth (37) that meshes with an external tooth (39) of the inserted end region (38) for forming the shape-restraining coupling part (35).

8. The drive unit according to any one of claims 1 to 7, characterized in that the driven shaft (27) has a first support part (28) and a second support part (29) arranged at a distance from the first support part (28), and the first support part (28) is arranged between the carrier part (26) and the second support part (29).

9. The drive unit according to claim 8, characterized in that the diameter of the first support part (28) is smaller than the diameter of a part (30) of the driven shaft (27) arranged between the support parts (28, 29).

10. The drive gear mechanism according to any one of claims 1 to 9, characterized in that the carrier part (26) is formed in a plate shape.

11. The drive gear mechanism according to any one of claims 1 to 10, characterized in that the carrier part (26) has at least one planet shaft (32) formed integrally with the carrier part (26).

12. The drive unit according to any one of claims 1 to 11, characterized in that the carrier part (26) is arranged within the motor housing (14), and the driven shaft (27) protrudes from the motor housing (14).

13. In an operating device for a brake system comprising an actuator element (3) and a drive unit (13) for driving the actuator element (3), the operating device characterized in that the drive unit (13) is formed according to any one of claims 1 to 12.

14. A brake system having the operating device (1) according to claim 13.

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