Magnetic Safety Brake Actuation for Reliable Elevator Emergency Braking
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Solution Overview
Problem
Existing elevator systems face challenges in providing reliable and efficient emergency braking, particularly in high-rise buildings, where mechanical governors and actuators are prone to mechanical failures and require complex mechanical linkages, leading to potential safety risks during freefall scenarios.
Innovation Solution
A safety brake system utilizing an actuator with an array of magnetic components, including a permanent magnet and electromagnets, that moves between ferromagnetic components to engage the safety brake without relying on frictional forces, triggered by electrical control to address overspeed or over-acceleration conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical governor and mechanically-actuated safety brake are used, then the safety brake can stop the elevator car, but the system is prone to mechanical failures and requires complex mechanical linkages
Solution Approach 1:
The patent replaces the traditional mechanical governor and mechanical actuator system with an electromagnetic actuator that uses magnetic fields to actuate the safety brake. The electromagnetic actuator includes a coil assembly that generates magnetic fields to move the brake shoe, eliminating the need for complex mechanical linkages and improving reliability by reducing mechanical failure points.
2Extent of automation
If electromagnetic actuators are used to control the safety brake, then the system can be electrically controlled, but the distance between ferromagnetic components must be minimized for effective operation
Solution Approach 1:
The patent employs magnetic flux redirection techniques where additional ferromagnetic components and flux paths are introduced to channel and concentrate the magnetic field. This allows the electromagnetic actuator to effectively actuate the safety brake even when the distance between ferromagnetic components is relatively large, maintaining electrical control capability without requiring minimal component spacing.
3Force
If friction-based mechanical actuators are used, then the safety brake can engage the guide rail, but the system requires significant force and complex mechanical structures
Solution Approach 1:
The patent replaces friction-based mechanical actuators with an electromagnetic actuator that uses magnetic attraction forces to engage the safety brake with the guide rail. The electromagnetic actuator generates sufficient braking force through magnetic fields without requiring complex mechanical force transmission mechanisms, reducing structural complexity while maintaining effective braking capability.
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
The system provides a simple, reliable, and energy-efficient emergency braking mechanism with reduced component count, minimizing space requirements and installation costs, while being less susceptible to false actuations and offering robust performance.
Implementation Method 1
the first magnetic component comprises one of a permanent magnet and an electromagnet and wherein the second magnetic components each comprise the other of a permanent magnet and an electromagnet
Implementation Method 2
the magnetic field between the array and the first ferromagnetic component is reduced and the magnetic field between the array and the second ferromagnetic component is augmented
Implementation Method 3
the first magnetic component comprises one of a permanent magnet and an electromagnet and wherein the second magnetic components each comprise the other of a permanent magnet and an electromagnet
Data Source
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AI summary
A safety brake system (40; 240) for use in a conveyance system is provided. The safety brake system (40; 240) includes a guide rail (20) and a conveyance component moveable along the guide rail (20). The safety brake system (40; 240) comprises a safety brake (42; 242), a linkage mechanism (56; 256) and an actuator (44; 144; 244) for the safety brake (42; 242). The a safety brake (42; 242) is moveable between a non-braking position where the safety brake (42; 242) is not in engagement with the guide rail (20) and a braking position where the safety brake (42; 242) is engaged with the guide rail (20). The actuator (44; 144; 244) is configured to be mounted to the conveyance component and positioned between first and second ferromagnetic components. The actuator comprises an array of magnetic components comprising a first magnetic component adjacent to and arranged between two second magnetic components. The first magnetic component comprises one of a permanent magnet and an electromagnet and the second magnetic components each comprise the other of a permanent magnet and a electromagnet. When the electromagnet (66; 166; 266) of the first or second magnetic components is switched from the first state to a second state, the magnetic field between the array and the first ferromagnetic component is reduced and the magnetic field between the array and the second ferromagnetic component is augmented so as to move the actuator (44; 144; 244) from the first position to a second position against the second ferromagnetic component.