Linear Drive Magnetic Cavity for Stable Elevator Safety Torque

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Solution Overview

Problem

Existing electric safety gears in elevators face limitations in torque control and stability due to unidirectional magnetic attraction forces and exponential reduction in magnetic force with increased spacing, restricting their application and safety coefficients.

Innovation Solution

A linear driving apparatus with a magnetically conductive device and a magnet, featuring a magnetic cavity and perpendicular winding coils, allows for controlled torque and stability by adjusting current and magnetic induction, and a safety gear apparatus with a spring mechanism for emergency braking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If common electromagnets are used to generate magnetic attraction force, then the safety gear can be actuated, but the magnetic attraction force is unidirectional and not in direct proportion with distance, making torque control difficult and stability poor

Engineering Contradiction:
Improvetorque stabilityVSAvoidtorque control
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the magnetic system adjustable and controllable. The linear driving apparatus uses a magnetically conductive device with winding coils that can be controlled to generate bidirectional magnetic forces. The system transitions from static unidirectional electromagnet attraction to dynamic bidirectional control, allowing the magnetic field strength and direction to be adjusted according to operational requirements, thereby achieving stable and controllable torque.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of the magnetic field by using winding coils with specific winding directions perpendicular to the magnet's pole direction. By controlling the current through the coils, the magnetic field strength and direction can be adjusted. This parameter control allows for precise torque management and stable operation, resolving the issue of poor stability and difficult torque control in conventional electromagnets.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If electromagnets are used with increased spacing or travel distance, then the application scenarios expand, but the magnetic force reduces exponentially, limiting the application scenarios and affecting safety coefficient

Engineering Contradiction:
Improveapplication scenariosVSAvoidmagnetic force
Core Design Contradiction:
Adaptability or versatilityVSForce

Solution Approach 1:

The patent replaces the conventional electromagnet mechanical system with a linear driving apparatus that uses a magnetically conductive device and winding coils. This substitution creates a more efficient magnetic circuit that maintains stronger magnetic force over increased distances. The perpendicular winding configuration and bidirectional magnetic field generation replace the traditional unidirectional electromagnet design, enabling expanded application scenarios while maintaining adequate magnetic force.

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

3Power

If the winding coil direction is parallel to the magnet pole direction, then the structure is simple, but the magnetic field interaction is less effective for torque control

Engineering Contradiction:
Improvemagnetic field interaction effectivenessVSAvoidcoil arrangement
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent applies dimensionality change by positioning the winding coil direction perpendicular to the magnet pole direction, rather than parallel. This orthogonal arrangement creates a three-dimensional magnetic field interaction that is more effective for generating torque. The perpendicular configuration allows the magnetic field lines to intersect the coil windings at optimal angles, maximizing the electromagnetic force generation while maintaining a manageable structural complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Enhances torque stability and safety by enabling controlled torque through perpendicular magnetic field interaction, and provides reliable emergency braking in elevators.

Implementation Method 1

the magnetically conductive device is provided with a winding coil, and in the magnetic cavity, the winding direction of the winding coil is perpendicular to the direction from the first end to the second end of the magnet

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the magnet is located between the first side portion and the second side portion and comprises at least a first end and a second end, magnetic pole directions of the first end and the second end are opposite

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 3

the magnetically conductive device comprises a first magnetically conductive mechanism, a second magnetically conductive mechanism, a first joint and a second joint, wherein the first magnetically conductive mechanism and the second magnetically conductive mechanism are connected through the first joint and the second joint to form the magnetic cavity

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Data Source

PatentEP3904262B1Linear driving apparatus, safety gear apparatus, and method for controlling elevator system
Publication Date: 2025.08.27 LIU YINGHUI
  • EP3904262B1 patent drawingFigure 1
  • EP3904262B1 patent drawingFigure 2
  • EP3904262B1 patent drawingFigure 3

AI summary

Disclosed are a linear driving apparatus, a safety gear apparatus, and an elevator system and a method for controlling same. The linear driving apparatus comprises a magnetically conductive device (10) and a magnet (30), wherein the magnetically conductive device (10) comprises at least a first side portion (101) and a second side portion (102), and is provided with an enclosed magnetic cavity (33); the magnet (30) is located between the first side portion (101) and the second side portion (102) and comprises at least a first end (31) and a second end (32), wherein the magnetic pole directions of the two ends are opposite, and the first end (31) and the second end (32) correspond to the first side portion (101) and the second side portion (102) respectively; the magnetically conductive device (10) is provided with a winding coil (22), and in the magnetic cavity (33), the winding direction of the winding coil is perpendicular to the direction from the first end (31) to the second end (32) of the magnet (30); and the magnetically conductive device (10) movably fits the magnet (30).