Brake booster and brake device including a brake booster of this type

• US 10,604,133 B2
• Filed: 07/13/2016
• Issued: 03/31/2020
• Est. Priority Date: 09/14/2015
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Deberling, Andreas, Ohm, Andreas, Weissinger, Daniel, Baur, Markus, Nagel, Willi
• Primary Examiner(s): Lopez, F Daniel
• Assistant Examiner(s): Quandt, Michael
• Application Number:
  US15/759,266
• Publication Number:
  US 20180251114A1
• Time in Patent Office: 1,357 Days
• CPC Class Codes: B60T 11/18 Connection thereof to initiating means
• CPC Class Codes: B60T 13/745 acting on a hydraulic system, e.g. a master cylinder
• CPC Class Codes: B60T 13/746 and mechanical transmission of the braking action
• CPC Class Codes: F16H 2025/2046 with gears arranged perpendicular to screw shaft axis, e.g. helical gears engaging tangentially the screw shaft
• CPC Class Codes: F16H 2025/2081 Parallel arrangement of drive motor to screw axis
• CPC Class Codes: F16H 25/20 Screw mechanisms with automatic reversal F16H25/12
• CPC Class Codes: F16H 25/2018 with both screw and nut being driven, i.e. screw and nut are both rotating

Abstract

A brake booster for a brake master cylinder of a motor vehicle, including a drive motor, which is connected/is connectable via a transmission to a pressure piston for the brake master cylinder, the transmission including a rotatable spindle nut having an inner thread, and a rotatably fixed axially displaceable spindle rod having an outer thread, the threads engaging with one another in order to convert a rotational movement of the drive motor into a translational movement of the spindle rod, and the spindle nut including an outer toothing, which is engaged with a toothing of a drive wheel of the transmission. It is provided that the spindle nut is displaceable axially relative to the drive wheel.

Claims

1. A brake booster for a brake master cylinder of a motor vehicle, comprising:

a drive motor; and

a transmission, the drive motor connected via the transmission to a pressure piston for the brake master cylinder, the transmission including a rotatable spindle nut having an inner thread and a rotatably fixed axially displaceable spindle rod having an outer thread, the threads engaging one another in order to convert a rotational movement of the drive motor into a translational movement of the spindle rod, and the spindle nut including an outer toothing, which is engaged with a toothing of a drive wheel of the transmission;

wherein the spindle nut is displaceable axially relative to the drive wheel and is co-axial with the drive wheel.

2. The brake booster as recited in claim 1, wherein the outer toothing of the spindle nut extends further over a sleeve-like section of the spindle nut than the toothing of the drive wheel, so that outer toothing of the spindle nut and the toothing of the drive wheel are engaged for rotational entrainment, regardless of an axial displacement of the spindle nut.

3. The brake booster as recited in claim 1, wherein the outer toothing of the spindle nut is designed as axial toothing.

4. A brake booster for a brake master cylinder of a motor vehicle, comprising:

a drive motor; and

a transmission, the drive motor connected via the transmission to a pressure piston for the brake master cylinder, the transmission including a rotatable spindle nut having an inner thread and a rotatably fixed axially displaceable spindle rod having an outer thread, the threads engaging one another in order to convert a rotational movement of the drive motor into a translational movement of the spindle rod, and the spindle nut including an outer toothing, which is engaged with a toothing of a drive wheel of the transmission;

wherein the spindle nut is displaceable axially relative to the drive wheel, and

wherein the drive wheel is designed as a drive internal gear and the toothing of the drive wheel is designed as an inner toothing of the drive internal gear.

5. The brake booster as recited in claim 4, wherein the spindle nut includes an axial stop for the drive internal gear.

6. The brake booster as recited in claim 5, wherein the axial stop is oriented at least in sections perpendicularly to an axial extension of the spindle nut.

7. The brake booster as recited in claim 5, wherein the axial stop is oriented at least in sections at an angle relative to the axial extension of the spindle nut.

8. The brake booster as recited in claim 5, wherein the axial stop is conical.

9. The brake booster as recited in claim 5, wherein the drive internal gear includes a stop designed complementarily to the axial stop.

10. The brake booster as recited in claim 5, wherein the outer toothing of the spindle nut extends into the axial stop.

11. The brake booster as recited in claim 5, wherein the spindle nut is assigned at least one spring element, which presses the spindle nut with the axial stop against the drive internal gear.