US 11,808,330 B2
Electromechanical brake pressure generator for a hydraulic braking system of a vehicle and method for manufacturing an electromechanical brake pressure generator
Mark Boehm, Lehrensteinsfeld (DE); and Claus Oehler, Karlsruhe (DE)
Assigned to ROBERT BOSCH GMBH, Stuttgart (DE)
Filed by Robert Bosch GmbH, Stuttgart (DE)
Filed on Apr. 20, 2020, as Appl. No. 16/852,864.
Claims priority of application No. 102019205977.5 (DE), filed on Apr. 25, 2019.
Prior Publication US 2020/0340563 A1, Oct. 29, 2020
Int. Cl. B60T 13/74 (2006.01); F16H 25/24 (2006.01); B60T 7/04 (2006.01); B60T 8/32 (2006.01)
CPC F16H 25/24 (2013.01) [B60T 7/042 (2013.01); B60T 8/3255 (2013.01); B60T 13/745 (2013.01); F16H 2025/2445 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An electromechanical brake pressure generator for a hydraulic braking system of a vehicle, the brake pressure generator comprising:
a threaded drive system that is configured to convert a drive-side rotary motion into a translatory motion and that includes:
a drive wheel that is rotatable by an electric motor;
a spindle nut that is arranged at an interior of the drive wheel and is rotationally fixed relative to the drive wheel, so that the spindle nut rotates whenever the drive wheel rotates;
a spindle which cooperates with a thread of the spindle nut so that the spindle is axially displaced with a rotation of the spindle nut;
a hydraulic piston of a piston/cylinder unit, the piston/cylinder unit being actuatable by the threaded drive system for hydraulic brake pressure generation; and
a housing of the piston/cylinder unit that at least partially surrounds the spindle, the spindle nut, and the hydraulic piston;
wherein:
an anti-twist protection, via which the spindle is secured against twisting during the rotation of the spindle nut, includes a torque support that (a) is part of the hydraulic piston and (b) engages in an axial recess of the housing, the recess forming a sliding surface for the torque support of the hydraulic piston;
the spindle nut includes a radially outwardly extending projection that has a first spindle nut surface facing in a first axial direction;
a groove extends, within a thickness of a wall of the housing, circumferentially around a longitudinal central axis of the spindle and is divided into multiple sections by the axial recess which is formed within the thickness of the wall of the housing perpendicularly to the groove;
the groove has a groove floor facing in the first axial direction and a groove ceiling facing in a second axial direction that is opposite to the first axial direction;
the drive wheel extends with a portion of the drive wheel passing radially inwards over an exterior edge of the housing that faces in the first axial direction towards the passing portion of the drive wheel, the passing portion of the drive wheel not being radially within the housing;
a radially interior region of the drive wheel is attached to the spindle nut and has a first drive wheel surface that faces in the second axial direction and that is within the housing;
the threaded drive system includes a bearing ring;
a radially exterior edge section of the bearing ring is held within the groove with a first exterior bearing ring surface of the radially exterior edge section of the bearing ring that faces in the first axial direction abutting against the groove ceiling and a second exterior bearing ring surface of the radially exterior edge section of the bearing ring that faces in the second axial direction abutting against the groove floor; and
a radially interior edge section of the bearing ring is held with a first interior bearing ring surface of the radially interior edge section of the bearing ring that faces in the first axial direction abutting against the first drive wheel surface of the radially interior region of the drive wheel and a second interior bearing ring surface of the radially interior edge section of the bearing ring that faces in the second axial direction abutting against the first spindle nut surface of the radially outwardly extending projection of the spindle nut, the bearing ring thereby fixing an axial position of the spindle nut relative to the housing, with the spindle nut being rotatable relative to the housing, while engagement of the torque support with the axial recess rotationally fixes the spindle relative to the housing, with the spindle being axially translatable relative to the housing.