Electromechanical Brake Booster Ball Screw Mechanism

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Solution Overview

Problem

Existing automotive braking assistance devices relying on vacuum boosters are susceptible to atmospheric pressure variations, leading to insufficient braking force and lack of manual braking capability when assistance fails, compromising safety.

Innovation Solution

An electromechanical integrated braking assistance device incorporating an electric motor with a position sensor and ECU, a ball screw mechanism, and a gear transmission system, which uses sensors to detect driver input and applies assistive force through PID control, ensuring stable and adaptable braking performance, including manual braking capability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a vacuum booster is used to provide assistant braking force, then the braking assistance function is achieved, but the braking force becomes insufficient when atmospheric pressure varies

Engineering Contradiction:
Improvebraking force reliabilityVSAvoidatmospheric pressure influence
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the traditional vacuum booster (pneumatic system) with an electric motor-driven ball screw mechanism. The electric motor converts electrical energy to mechanical linear motion through the ball screw, eliminating dependence on atmospheric pressure while maintaining the ability to generate sufficient braking assistance force. This substitution resolves the contradiction by removing the harmful influence of atmospheric pressure variations on braking reliability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a vacuum booster is used for braking assistance, then assistant force is provided, but manual braking capability is lost when assistance fails

Engineering Contradiction:
Improvesafety marginVSAvoidmanual braking capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The electric motor-driven mechanism serves dual functions: it provides powered braking assistance when needed, and allows direct manual operation when assistance is not required or has failed. The ball screw mechanism can be manually operated to move the piston, maintaining manual braking capability while enabling electric assistance during normal operation. This multi-functionality resolves the contradiction by ensuring both assisted and manual braking capabilities are preserved.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If an electromechanical integrated system is implemented, then braking reliability and adaptability are improved, but device complexity increases

Engineering Contradiction:
Improveassistant force reliabilityVSAvoidsystem structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the complex pneumatic system of traditional vacuum boosters with a more compact electromechanical system consisting of an electric motor, ball screw, and piston assembly. This substitution reduces overall system complexity while improving reliability, as the electromechanical system has fewer components susceptible to environmental degradation and maintains consistent performance across varying atmospheric conditions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides a reliable and stable braking assistance by converting motor rotation into linear movement, maintaining efficiency and enabling manual braking, thus enhancing safety and comfort by replicating conventional vacuum booster characteristics.

Implementation Method 1

a lead screw is sleeved over the pedal input rod, and a ball nut is sleeved over the lead screw

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 2

a lead screw is sleeved over the pedal input rod

Methodology Applied
Scientific EffectScrew: Screw

Implementation Method 3

a ball nut is sleeved over the lead screw; a ball nut bushing is fixed to the ball nut by being sleeved over the ball nut

Methodology Applied
Scientific EffectBall Bearing: Ball Bearing

Implementation Method 4

the electric motor meshes with the driven gear via a gear transmission mechanism or a belt mechanism

Methodology Applied
Scientific EffectGear: Gear

Implementation Method 5

the electric motor meshes with the driven gear via a gear transmission mechanism or a belt mechanism

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 6

an absolute displacement sensor or a relative displacement sensor is connected to the pedal input rod

Methodology Applied
Scientific Effect:

Implementation Method 7

restoring springs are sleeved over both the pedal input rod and the output rod

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP3279047B1Mechanical, electric and magnetic integrated brake booster apparatus
Publication Date: 2019.11.13 NINGBO TUOPU INTELLIGENT BRAKE SYST
  • EP3279047B1 patent drawingFigure 1
  • EP3279047B1 patent drawingFigure 2

AI summary

The invention relates to an electromechanical-magnetically integrated braking assistance device, comprising an electrical motor, an oil holder, a braking main cylinder, an assistant force generating portion, and a pedal input rod, an absolute displacement sensor or a relative displacement sensor is connected to the pedal input rod; a lead screw is sleeved over the pedal input rod, and a ball nut is sleeved over the lead screw; a ball nut bushing is fixed to the ball nut by being sleeved over the ball nut; a driven gear is fixed to the ball nut bushing by being sleeved over the ball nut bushing; and the electric motor meshes with the driven gear via a transmission mechanism. An end of the lead screw which passes through the ball nut bushing has an aperture, into which a feedback disc is installed; an end of the feedback disc is connected to an end of an output rod which is coaxially arranged with the lead screw inside the assistant force generating portion, and another end of the output rod extends into the braking main cylinder and is connected to a piston of the braking main cylinder. The invention is simple in structure, and by using an electromechanical-magnetically integrated way, all the characteristics of a conventional vacuum booster have reappeared, and meanwhile the reliability of assistant force is increased, thus ensuring the stability and following characteristic during the braking process.