Composite Elevator Brake Hub Reducing Shaft Noise

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Solution Overview

Problem

Elevator machines produce noise due to metal-to-metal contact between the splined section of the rotor and the machine shaft, which is undesirable in modern elevator systems aiming for quieter operation.

Innovation Solution

A non-metallic elevator brake hub is introduced, fixed to a flange portion of the rotor, with a splined hub opening that aligns with a splined rotor opening, engaging a corresponding splined portion of the shaft, reducing metal-to-metal contact and incorporating a non-metallic material to minimize noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a metallic rotor with splined section is used to engage the machine shaft, then the structural strength and torque transmission are improved, but noise is generated due to metal-to-metal contact during sliding

Engineering Contradiction:
Improvestructural strengthVSAvoidnoise
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The rotor hub is constructed as a composite structure comprising a metallic substrate providing structural strength and a non-metallic coating layer (such as polymer, plastic, or elastomer) applied to the splined section. This composite material approach allows the rotor to maintain mechanical strength while the non-metallic layer reduces noise by minimizing metal-to-metal contact with the shaft, thereby resolving the contradiction between strength and noise generation.

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If a non-metallic hub is used to reduce noise, then noise is reduced by minimizing metal-to-metal contact, but the torque transmission capability may be compromised

Engineering Contradiction:
ImprovenoiseVSAvoidtorque transmission
Core Design Contradiction:
Object-generated harmful factorsVSForce

Solution Approach 1:

The composite hub structure combines a metallic substrate that provides the necessary mechanical strength and torque transmission capability with a non-metallic coating layer that reduces noise. The metallic substrate ensures adequate force transmission while the non-metallic layer minimizes noise, thus resolving the contradiction between noise reduction and torque transmission capability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention modifies the surface properties of the hub by applying a non-metallic coating with specific friction characteristics. By controlling the coefficient of friction and surface properties of the coating material, the design maintains sufficient torque transmission while significantly reducing noise compared to pure metal-to-metal contact.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2066578B1Elevator brake with composite brake hub
Publication Date: 2011.12.28 OTIS ELEVATOR CO
  • EP2066578B1 patent drawingFigure 1
  • EP2066578B1 patent drawingFigure 2
  • EP2066578B1 patent drawingFigure 3~5

AI summary

An elevator brake (20) rotor for use in an elevator machine (10) includes a non-metallic elevator brake hub (36) and a metal flange (34), both of which have an opening with a splined portion for guiding axial movement of the rotor along a rotable shaft (14). This arrangement reduces metal-to-metal contact between the rotor and shaft and reduces noise.