Brake Device With Circumferential Cam Contact Points

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Solution Overview

Problem

Existing brake devices for vehicle seat height adjustment mechanisms are heavy and lack stability in operation, limiting their weight reduction potential and operational feel.

Innovation Solution

A brake device with three or more brake cams arranged in a circumferential direction, featuring contact points shifted from the center plane by no more than 16% of the distance between the brake surfaces, ensures efficient force transmission and stable operation by distributing the force around the axis of rotation, preventing rotational motion of the brake cams and allowing direct force transmission without loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If conventional brake device design is used, then braking capability is maintained, but weight is excessive

Engineering Contradiction:
Improveweight of brake deviceVSAvoidbraking capability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The brake device is segmented into multiple brake cams (at least two) arranged in the circumferential direction, allowing the braking function to be distributed across multiple smaller components rather than a single large component, enabling weight reduction while maintaining braking capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The contact portions of the brake cams are positioned at specific locations (on the axis-of-rotation side or on the both-end reference plane) to optimize force transmission efficiency, ensuring that the braking force is applied at the most effective location while minimizing unnecessary material

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If brake device is lightweighted, then weight is reduced, but operational stability deteriorates

Engineering Contradiction:
Improveweight of brake deviceVSAvoidoperational stability
Core Design Contradiction:
Weight of moving objectVSStability of the object's composition

Solution Approach 1:

Multiple brake cams are arranged circumferentially to distribute the braking force around the axis of rotation, creating a more balanced and stable force distribution that improves operational stability while allowing each individual cam to be lighter

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The brake cams work together in combination, with their collective braking force providing stable operation. The coordinated action of multiple cams creates a more stable braking system than a single cam could achieve alone

Inventive Principle:
Principle #5Merging (Combining)

3Power

If contact points are positioned on the both-end reference plane, then force transmission efficiency is maximized, but brake cam weight must be sufficient

Engineering Contradiction:
Improveforce transmission efficiencyVSAvoidweight of brake cams
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The contact portions are positioned at the optimal locations (on the axis-of-rotation side or on the both-end reference plane) to maximize force transmission efficiency, ensuring that the braking force is applied where it is most effective while minimizing the weight of the brake cams

Inventive Principle:
Principle #3Local quality

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

This configuration reduces the weight of the brake device while maintaining braking capability and providing a stable operating feel by distributing the force effectively and preventing unwanted rotation of the brake cams, thus enhancing the overall performance.

Implementation Method 1

a rotational force imparted to the brake cams by the output-side rotary member cannot go beyond the frictional force which can be produced between the brake cams and the outer race

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2860422B1Brake device
Publication Date: 2019.07.10 TS TECH CO LTD
  • EP2860422B1 patent drawingFigure 1
  • EP2860422B1 patent drawingFigure 2
  • EP2860422B1 patent drawingFigure 3

AI summary

Provided is a brake device including: an outer race (10) having a cylindrical inner peripheral surface (11A); at least two brake cams (20) arranged inside the outer race (10) in a circumferential direction, each brake cam having brake surfaces (21) located at both ends in the circumferential direction of a side of the brake cam facing the outer race (10), each brake surface being contactable with the inner peripheral surface of the outer race; and an output-side rotary member (30) arranged at radially inner sides of the respective brake cams (20), the output-side rotary member including contact portions (33A, 33B) contactable with surfaces of the brake cams (20) facing the radially inner sides. Contact points (51A, 51B) at which the respective contact portions and the respective brake cams (20) are contactable are on an axis-of-rotation side (on which an axis (56) of rotation of the output-side rotary member (30) is located) of a both-end reference plane (S1) (plane connecting outer ends of the respective brake surfaces (21) located at the both ends of a corresponding brake cam (20)), or on the both-end reference plane (S1).