Disc Brake Pad Groove Layout for Stable Elevator Braking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In elevator devices with disc brake systems, high braking energy generates excessive frictional heat, leading to gas and wear debris formation, which destabilizes frictional characteristics and requires effective removal without compromising brake pad strength.

Innovation Solution

The design incorporates brake pads with intersecting linear grooves, where one groove extends through the center and others are formed perpendicular to the sliding contact direction, allowing for quick discharge of gas and debris while maintaining pad strength by positioning grooves to avoid the center and facilitate gravity-driven debris removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If grooves are formed on the brake pad to remove gas and wear debris, then frictional characteristics are stabilized, but the strength of the brake pad is reduced

Engineering Contradiction:
Improvefrictional characteristics stabilityVSAvoidbrake pad strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The brake pad is designed with grooves only in specific regions (non-central areas) rather than uniformly across the entire pad. This localized groove configuration removes gas and wear debris from critical friction zones while preserving the structural integrity and strength of the overall brake pad material.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The groove configuration employs asymmetric positioning relative to the brake pad center, with grooves strategically placed in peripheral regions. This asymmetric design optimizes debris removal efficiency while maintaining symmetric load distribution and structural strength during braking operations.

Inventive Principle:
Principle #4Asymmetry

2Loss of time

If braking force is increased to stop the elevator, then stopping time is reduced, but frictional heat and temperature rise are increased

Engineering Contradiction:
Improvestopping timeVSAvoidfrictional face temperature
Core Design Contradiction:
Loss of timeVSTemperature

Solution Approach 1:

The grooves in the brake pad convert the harmful accumulation of gas and wear debris into a beneficial self-cleaning mechanism. As the brake pad rotates during braking, the grooves automatically eject accumulated debris and gas, preventing friction characteristic degradation and enabling sustained high-braking-force operation without temperature-induced performance loss.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 effectively removes gas and wear debris from the brake pad's center, stabilizing frictional characteristics and maintaining braking performance in high-speed elevator applications.

Implementation Method 1

allowing for quick discharge of gas and debris while maintaining pad strength by positioning grooves to avoid the center and facilitate gravity-driven debris removal

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3369687B1Elevator device
Publication Date: 2024.07.17 HITACHI LTD
  • EP3369687B1 patent drawingFigure 1~2
  • EP3369687B1 patent drawingFigure 3~4
  • EP3369687B1 patent drawingFigure 5~6

AI summary

An elevator device including a disc brake system capable of quickly removing gas and wear debris generated from the vicinity of the center of a brake pad without lowering the strength of the brake pad to provide stable frictional characteristics is provided. The elevator device of the present invention is characterized in that a brake pad of a disc brake system has one linear groove formed to extend through substantially the center of the brake pad, and two other linear grooves formed to be perpendicular to the one linear groove and face each other with the center therebetween at positions away from the center, and that either of the one linear groove and the two linear grooves is/are formed along a sliding contact direction of the brake pad and a brake disc.