Elevator Brake Magnet Assembly With Wear-Resistant Friction Blocks

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Solution Overview

Problem

Elevator brake systems with traditional magnet assemblies face challenges in achieving high braking force, increased life, and reduced costs, particularly in electromechanical actuators where machining costs are high and wear issues are prevalent.

Innovation Solution

The development of magnet assemblies for elevator systems that include sheet metal block assemblies with friction engagement surfaces, either formed from laminated sheet metal or powdered metal sintering, and an encapsulating non-magnetic body, which can engage with a guide rail to actuate a safety brake, offering improved friction engagement and reduced manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional magnet assemblies use machined block structures, then manufacturing precision can be achieved, but machining costs increase and manufacturing complexity increases

Engineering Contradiction:
Improveblock structure precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces traditional mechanical machining processes with additive manufacturing (3D printing) technology. The magnet assembly blocks are fabricated directly through layer-by-layer material deposition, eliminating the need for complex CNC machining operations. This substitution reduces machining costs while maintaining manufacturing precision through digital model control.

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

Solution Approach 2:

The invention changes the manufacturing method parameter from subtractive machining to additive fabrication. By using selective laser melting or direct metal deposition processes, the patent achieves complex geometries with reduced tooling costs and simplified manufacturing workflows, directly addressing the cost-precision contradiction.

Inventive Principle:
Principle #35Parameter changes

2Strength

If magnet assemblies use traditional solid block structures, then structural strength is maintained, but wear resistance decreases and service life is reduced

Engineering Contradiction:
Improveblock structural strengthVSAvoidservice life
Core Design Contradiction:
StrengthVSDuration of action of moving object

Solution Approach 1:

The patent incorporates reinforcement elements such as embedded fibers, particulate reinforcements, or multi-material compositions within the additively manufactured blocks. These composite structures enhance wear resistance at friction surfaces while preserving the overall structural strength of the magnet assembly, thereby extending service life.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention applies different material properties to different regions of the block structure. High-strength materials are used in load-bearing areas, while wear-resistant coatings or reinforced compositions are applied at friction contact surfaces. This localized quality differentiation optimizes both strength and durability without compromising overall performance.

Inventive Principle:
Principle #3Local quality

3Force

If magnet assemblies are designed with complex friction engagement surfaces, then braking force is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvebraking forceVSAvoidfriction surface geometry
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent uses additive manufacturing to directly create complex friction engagement surfaces without requiring complex machining tools or multiple assembly steps. The 3D printing process can generate intricate geometries, conformal cooling channels, and optimized friction surfaces directly from digital models, simplifying the manufacturing system while achieving high braking force.

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

These magnet assemblies provide robust, cost-effective, and reliable braking solutions by minimizing machining costs, reducing wear, and enhancing the efficiency of electromechanical actuators, leading to increased product life and improved braking performance.

Implementation Method 1

magnet assemblies of electromechanical assemblies for elevator systems... magnet, a first block assembly arranged on a first side of the magnet, and a second block assembly arranged on a second side of the magnet opposite the first block assembly... configured to engage with the guide rail and act upon a connecting rod to actuate a safety brake

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

magnet assemblies that are configured to provide a friction interface to generate a braking force when activated and engaged with a guide rail of an elevator system... Each of the first block assembly and the second block assembly each include a respective friction engagement surface

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3932843B1Magnet assemblies of electromechanical actuators for elevator systems
Publication Date: 2024.10.16 OTIS ELEVATOR CO
  • EP3932843B1 patent drawingFigure 1
  • EP3932843B1 patent drawingFigure 2
  • EP3932843B1 patent drawingFigure 3A

AI summary

Magnet assemblies (700) for electromechanical assemblies of elevator systems are described. The magnet assemblies include a magnet (706) and first and second block assemblies (702; 704) arranged on opposite sides of the magnet (706). In some configurations, the block assemblies (702; 704) each include a respective friction engagement surface (714) and are formed of layers (708) of sheet metal, with a portion of the layers (708) having blade teeth that form a friction engagement surface (714) for engagement with a guide rail. In some configurations, each of the block assemblies (702; 704) are formed from powder metal sintering and include a monolithic tooth configuration configured to form a friction engagement surface (714) for engagement with a guide rail. In some configurations each of the block assemblies (702; 704) includes an abrasive coating configured to form a friction engagement surface for engagement with a guide rail.