Nested Lead Screw and Output Shaft for Compact Electro-Mechanical Brakes

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Solution Overview

Problem

Existing electro-mechanical brake apparatuses face challenges in miniaturization due to their axial size, which hinders their integration into vehicle wheel spaces.

Innovation Solution

The integration of a lead screw within an output shaft, combined with a brake caliper and speed reducer, reduces the axial length of the brake apparatus by embedding or nesting the output shaft in the lead screw, allowing for a compact design that fits within vehicle wheel spaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the electro-mechanical brake apparatus uses a conventional separate structure for lead screw and output shaft, then the transmission connection is reliable, but the axial size is large which hinders miniaturization

Engineering Contradiction:
Improveaxial sizeVSAvoidstructural complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The output shaft is nested within the lead screw structure, with the output shaft passing through the lead screw along its axial direction. This nesting arrangement allows the lead screw to embed or be embedded in the output shaft, significantly reducing the axial size of the electro-mechanical brake apparatus while maintaining reliable transmission connection between the two components.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of moving object

If the output shaft is embedded in the lead screw to reduce axial length, then miniaturization is achieved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveaxial lengthVSAvoidembedding precision
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The embedding connection between the output shaft and lead screw is divided into discrete segments: an embedding portion on the lead screw and a corresponding embedding structure on the output shaft. This segmentation allows for standardized manufacturing of each component while ensuring precise fitting through dedicated embedding interfaces, reducing overall manufacturing difficulty despite the compact design.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the brake apparatus is miniaturized to fit wheel space, then adaptability to vehicle integration is improved, but the structural complexity increases

Engineering Contradiction:
Improvewheel space adaptabilityVSAvoidstructural complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The lead screw and output shaft are merged into a integrated structure where the output shaft is embedded within the lead screw. This merging eliminates the need for separate mounting structures and external connection mechanisms, achieving miniaturization that enables adaptation to vehicle wheel spaces while actually simplifying the overall structural complexity through component integration.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4621257A1Electro-mechanical brake apparatus in which lead screw embeds or is embedded in output shaft, and vehicle
Publication Date: 2025.09.24 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4621257A1 patent drawingFigure 1
  • EP4621257A1 patent drawingFigure 2~3
  • EP4621257A1 patent drawingFigure 4~5

AI summary

This application provides an electro-mechanical brake apparatus (100) in which a lead screw (21) embeds or is embedded in an output shaft (31), and a vehicle. The electro-mechanical brake apparatus (100) includes a brake caliper (10), a ball lead screw (20), and a speed reducer (30). The ball lead screw includes the lead screw (21) and a screw nut (22), the speed reducer (30) includes the output shaft (31), one end of the output shaft (31) is configured to drive the lead screw to rotate, the screw nut is configured to move with rotation of the lead screw in an axial direction of the lead screw, and the brake caliper (10) is configured to: fasten the speed reducer (30) and accommodate the lead screw (21) and the screw nut (22). An end face of the lead screw (21) faces the speed reducer (30) in the axial direction of the lead screw, and the end face includes: an axial groove, where the one end of the output shaft is configured to be embedded in the axial groove in the axial direction of the lead screw, and the axial groove is configured to be in transmission connection to the one end of the output shaft (31); or an axial protrusion, where the axial protrusion is configured to be embedded in or nest the one end of the output shaft (31) in the axial direction of the lead screw (21), and the axial protrusion is configured to be in transmission connection to the one end of the output shaft (31).