Eddy Current Brake Magnet Layout for High Torque Switching
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Solution Overview
Problem
Eddy current decelerating apparatuses face challenges in generating higher braking torque while minimizing unnecessary braking torque generation, especially as vehicle performance improves.
Innovation Solution
An eddy current decelerating apparatus with a cylindrical brake member, primary and secondary permanent magnets, pole pieces, and a switching mechanism, where the secondary magnets are arranged in a trapezoidal shape to form magnetic circuits that enhance braking torque in the braking state and minimize magnetic flux leakage in the non-braking state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the magnets are moved axially to switch between braking and non-braking states, then the switching mechanism is simple, but a large space is required for axial movements
Solution Approach 1:
The patent transitions from axial movement (one dimension) to circumferential rotation (another dimension) for switching between braking and non-braking states. The magnets rotate circumferentially around the rotary shaft instead of moving axially, which changes the dimension of movement and resolves the space constraint while maintaining switching functionality.
2Force
If the magnets are positioned to face pole pieces entirely for braking, then braking torque is generated, but magnetic flux leakage occurs in non-braking state
Solution Approach 1:
The patent applies local quality by positioning magnets at specific angular intervals (e.g., 120 degrees) rather than uniformly distributing them. This localized arrangement ensures that when one magnet faces a pole piece for braking, other magnets are positioned to minimize magnetic flux leakage to the brake member, thus achieving both effective braking and reduced unwanted magnetic effects.
Solution Approach 2:
The patent uses asymmetric positioning of magnets relative to pole pieces during non-braking state. The magnets are arranged such that they do not symmetrically face the pole pieces, which prevents formation of complete magnetic circuits between magnets and brake member, thereby reducing magnetic flux leakage while maintaining the ability to generate braking torque when needed.
3Force
If vehicle performance is improved, then higher braking torque is required, but unnecessary braking torque generation must be minimized
Solution Approach 1:
The patent implements dynamic switching between braking and non-braking states through circumferential rotation of magnets. This dynamic mechanism allows the system to adapt to varying vehicle performance requirements by precisely controlling when magnetic circuits are formed between magnets and brake member, ensuring high braking torque is generated only when needed while minimizing energy loss from unnecessary braking.
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 apparatus effectively generates high braking torque during braking and suppresses unnecessary braking torque during non-braking, optimizing performance for improved vehicle deceleration.
Implementation Method 1
magnetic fluxes outgoing from the magnets reach the brake member through the pole pieces
Implementation Method 2
on the inner peripheral surface of the brake member rotating together with the rotary shaft, eddy currents are generated
Implementation Method 3
As a result, breaking torque acts on the brake member, and the rotating speed of the rotary shaft is reduced
Data Source
Figure 1~2
Figure 3~4
AI summary
A decelerating apparatus includes a brake member (1), primary permanent magnets (3), secondary permanent magnets (4) and pole pieces (5). The primary permanent magnets (3) are arranged in a circumferential direction to face an inner or outer peripheral surface of the brake member (1) with a gap in between. Each of the primary permanent magnets (3) has two opposite magnetic poles arranged in a radial direction. The secondary permanent magnets (4) and the pole pieces (5) are placed in the gap between the brake member (1) and the primary permanent magnets (3) and arranged in the circumferential direction. Each of the secondary permanent magnets (4) has two opposite magnetic poles arranged in the circumferential direction. Each of the pole pieces (5) is positioned between and is in contact with adjacent secondary permanent magnets (4). Magnetic pole arrangements of adjacent primary permanent magnets (3) are opposite to each other. Magnetic pole arrangements of adjacent secondary permanent magnets (4) are opposite to each other. Each of the secondary permanent magnets (4) has a trapezoidal cross-sectional shape including an upper base and a lower base being longer than the upper base.