US-12623648-B2 - Drive device for an electromechanical brake device, brake device

US12623648B2US 12623648 B2US12623648 B2US 12623648B2US-12623648-B2

Abstract

A drive device for an electromechanical brake device, in particular a brake booster. The drive device includes an electric motor that has a housing and a rotor shaft rotatably mounted in the housing. The rotor shaft is coupled to a transmission, in particular a planetary gear train that comprises a ring gear. The rotor shaft is rotatably mounted in the housing by at least one roller bearing. The roller bearing is held in a bearing seat of a bearing cover situated in the housing. The bearing cover has a ring-gear portion, which is spaced apart from the bearing seat and in which the ring gear is situated.

Inventors

Mark Boehm
Sebastian Martin Reichert
Willi Nagel

Assignees

ROBERT BOSCH GMBH

Dates

Publication Date: 20260512
Application Date: 20210705
Priority Date: 20200806

Claims (12)

1 . A drive device for an electromechanical brake booster, the drive device comprising: an electric motor; a bearing cover situated in a housing of the electric motor; a rotor shaft rotatably mounted in the housing by at least one roller bearing that is held in a bearing seat of the bearing cover; and a transmission to which the rotor shaft is coupled and that includes a planetary gear train having a ring gear that is situated in a ring-gear portion of the bearing cover; wherein: the ring-gear portion is spaced apart from the bearing seat; and a set of multiple radial elevations, which are spaced apart from one another in a circumferential direction, cooperate with a single corresponding recess to prevent rotation of the ring gear relative to the bearing cover.
2 . The drive device according to claim 1 , wherein the planetary gear train further includes a sun gear situated in a rotationally fixed manner on the rotor shaft and a plurality of planetary gears.
3 . The drive device according to claim 2 , wherein the transmission is a spindle transmission that includes an axially slidably supported spindle and a spindle gear that (a) is rotatably supported and engaged with the spindle by way of a helical gearing and (b) forms a planetary gear support for the planetary gears.
4 . The drive device according to claim 3 , wherein the ring gear includes a meshing portion and a centering portion formed integrally with the meshing portion, the meshing portion interacts with the planetary gears, the ring gear is supported on a bearing cover of the spindle transmission by way of the centering portion of the ring gear, and the centering portion of the ring gear extends axially from the meshing portion in a direction away from an axial position of the planetary gears towards an axial position of the spindle.
5 . The drive device according to claim 4 , wherein the bearing cover of the spindle transmission extends axially between a first end of bearing cover of the spindle transmission and a second end of the bearing cover of the spindle transmission, the first end of the bearing cover of the spindle transmission is more distal to the axial position of the planetary gears than second end of the bearing cover of the spindle transmission, and the second end of the bearing cover of the spindle transmission is at more radially inward position than the first end of the bearing cover of the spindle transmission.
6 . The drive device according to claim 1 , wherein the set of multiple radial elevations is provided as part of the ring-gear portion of the bearing cover and is positioned within the single corresponding recess provided in the ring gear.
7 . The drive device according to claim 1 , wherein the set of multiple radial elevations is provided as part of the ring gear is positioned within the single corresponding recess provided in the ring-gear portion of the bearing cover.
8 . The drive device according to claim 1 , wherein: the single corresponding recess is one of a plurality of recesses spaced apart from one another in the circumferential direction; the multiple radial elevations of the set form one of a plurality of subsets of a plurality of radial elevations; and each respective one of the subsets (i) includes a respective one or more of the plurality of radial elevations and (ii) cooperates with a respective corresponding one of the plurality of recesses.
9 . The drive device according to claim 8 , wherein the subsets of the radial elevations and the radial recesses are situated in an evenly distributed manner about a circumference of the ring-gear portion.
10 . A drive device for an electromechanical brake booster, the drive device comprising: an electric motor; a transmission that includes a planetary gear train having a ring gear that forms a ring-gear portion of a bearing cover situated in a housing of the electric motor, so that the ring gear is integrally developed with the bearing cover; and a rotor shaft that is coupled to the transmission and that is rotatably mounted in the housing by at least one roller bearing that is held in a bearing seat of the bearing cover, wherein the bearing seat is spaced apart from the ring-gear portion of the bearing cover.
11 . The drive device according to claim 10 , wherein the drive device is arranged to drive a hydraulic pressure generator of a brake device of a motor vehicle.
12 . A brake device for a motor vehicle, the brake device comprising: a hydraulic pressure generator; and a drive device configured to drive the hydraulic pressure generator, the drive device including: an electric motor; a bearing cover situated in a housing of the electric motor; a rotor shaft rotatably mounted in the housing by at least one roller bearing that is held in a bearing seat of the bearing cover; and a transmission to which the rotor shaft is coupled and that includes a planetary gear train having a ring gear that is situated in a ring-gear portion of the bearing cover; wherein: the ring-gear portion is spaced apart from the bearing seat; and a set of multiple radial elevations, which are spaced apart from one another in a circumferential direction, cooperate with a single corresponding recess to prevent rotation of the ring gear relative to the bearing cover.

Description

FIELD The present invention relates to a drive device for an electromechanical brake device, in particular a brake booster, comprising an electric motor that has a housing and a rotor shaft rotatably mounted in the housing, which rotor shaft is coupled to a transmission that has a ring gear, wherein the rotor shaft is mounted in the housing by at least one roller bearing, and wherein the roller bearing is held in a bearing seat of a bearing cover situated in the housing. The present invention further relates to a brake device for a vehicle, in particular a motor vehicle comprising a hydraulic pressure generator, which is in particular fluidically connected to at least one brake circuit comprising at least one hydraulically actuatable brake device and a drive device for driving the hydraulic pressure generator. BACKGROUND INFORMATION Propulsion devices of the aforementioned type are available in the related art. Given the increasing electrification of motor vehicles in particular, the desire to achieve individual brake boosting is increasing, as well as the ability to perform braking operations independently of brake pedal operation, e.g., in autonomous driving operation. Brake devices are therefore increasingly used in vehicles, which generate a brake pressure, not, or not only, by way of a braking force applied by a user on a brake pedal, but rather detached therefrom, with the aid of an electrically controllable actuator or an electrically controllable drive device. To this end, it is conventional to employ a hydraulic pressure generator in brake devices, which generator is drivable by means of a drive device in order to generate upon demand a hydraulic pressure in a brake circuit or brake system, independently of a brake pedal operation by a user, in a manner useful for performing one or more brake operations. In particular, brake devices are available in the related art in which the controllable drive device replaces the conventional vacuum brake booster. SUMMARY A drive device according to the present invention may have the advantage that it is particularly space-saving, facilitates assembly, and reduces assembly and manufacturing costs. According to the present invention, it is provided that the bearing cover of the drive device has a ring-gear portion, which is spaced apart from the bearing seat for the roller bearing and in which the ring gear is situated. Thus, the drive device according to the present invention results in both the roller bearing and the ring gear being retained by the bearing cover in the housing of the drive device, in particular the electric motor. Whereas a separate bearing for the ring gear has conventionally been provided, in particular welded in the outer ring of the roller bearing, the present invention results in an easier assembly in which the laborious welding process is in particular eliminated. According to a preferred further development of the present invention, the bearing cover in the ring-gear portion comprises at least one, in particular multiple radial elevations and/or radial recesses, which are spaced apart in the circumferential direction from one another, and which cooperate with radial recesses and/or radial elevations of the ring gear inserted in the ring-gear portion in order to prevent rotation. A rotation lock or anti-rotation means is thus formed between the bearing cover and the ring gear, thus preventing the ring gear from rotating along. This ensures that the ring gear is fixedly retained in the housing. By virtue of the radial elevations and/or radial recesses of the ring gear on the one hand and the radial recesses or radial elevations of the ring gear portion on the other hand, a simple positive-locking connection in the circumferential direction is ensured. Preferably, at least one radial recess is present for each of the radial elevations, into which recess the respective radial elevation can engage. Furthermore, according to an example embodiment of the present invention, it is preferably provided that the radial elevations and/or radial recesses are situated in an evenly distributed manner about the circumference of the ring gear portion. This even distribution ensures that an even transmission of force from the ring gear to the ring-gear portion is ensured, which results in an even load and thus a long service life for the drive device. According to a preferred further development of the invention, the ring gear portion forms the ring gear, so that the ring gear is formed integrally with the bearing cover. In this case, the ring gear thus constitutes an integral part of the bearing cover. This reduces the number of individual parts of the drive device and reduces manufacturing costs. In particular, due to the integral design, an additional anti-rotation feature is omitted, thereby further reducing manufacturing costs compared to the aforementioned embodiment. According to one preferred embodiment of the present invention, the ring gear toget