Electromagnetic Brake Armature Control via Gradient Pole Surfaces
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Solution Overview
Problem
Conventional electromagnetic brakes lack control over armature disk movement speed and suffer from inefficient magnetic force distribution, leading to uncontrolled acceleration and increased friction, which affects braking torque and noise levels.
Innovation Solution
The method involves a spring-loaded brake design with varying gradient pole surfaces on the coil carrier and armature disk, allowing for adjustable magnetic flux to balance magnetic and spring forces, enabling negative feedback and thus controlling armature disk movement speed and optimizing magnetic force distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional electromagnetic brakes use planar pole surfaces, then the structure is simple, but the magnetic force distribution is inefficient causing uncontrolled acceleration
Solution Approach 1:
The patent applies local quality by designing pole surfaces with varying gradients instead of uniform planar surfaces. The gradient varies locally across the pole surface to optimize magnetic flux distribution in different regions, enabling controlled armature disk movement while maintaining manufacturing feasibility through systematic surface profiling.
Solution Approach 2:
The invention implements dynamics by creating a magnetic force distribution that dynamically adapts to the armature disk position. The varying gradient pole surfaces ensure that magnetic force changes continuously during the stroke region, providing speed control without requiring external position sensors or complex control systems.
2Force
If the magnetic force increases with decreasing air gap, then the braking force is strong, but the acceleration becomes uncontrolled and friction increases
Solution Approach 1:
The patent implements feedback by designing the pole surface gradient such that the magnetic force automatically adjusts in response to air gap changes. As the armature disk moves and the air gap decreases, the varying gradient ensures that magnetic force increases in a controlled manner rather than exponentially, preventing runaway acceleration and reducing harmful friction and noise.
Solution Approach 2:
The invention applies parameter changes by modifying the geometric parameters of the pole surfaces (gradient variations) to change the magnetic force characteristic. This transforms the magnetic force-air gap relationship from a steep nonlinear curve to a more linear controlled curve, enabling force control while minimizing harmful effects.
3Loss of time
If the armature disk moves quickly to the closed position, then the response time is short, but the impact noise and friction increase
Solution Approach 1:
The patent uses dynamics by creating a continuously varying magnetic force during the armature disk movement. The varying gradient pole surfaces generate a magnetic force profile that accelerates the armature disk efficiently while automatically decelerating it near the closed position, reducing impact noise without sacrificing response time.
Solution Approach 2:
The invention applies beforehand cushioning by designing the pole surface gradient to anticipate the approaching armature disk. As the air gap decreases, the gradient variation pre-limits the magnetic force increase, creating a natural cushioning effect that reduces impact velocity and noise before the armature disk reaches the closed position.
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
This design allows for adjustable braking torque, reduced noise, and improved mechanical efficiency by optimizing the ratio of magnetic and spring forces, enabling stable and controllable armature disk movement without external position sensors and independent of temperature, with enhanced power density and reduced friction.
Implementation Method 1
a solenoid (5), and an armature disk (7)... due to the variation of the excitation of the solenoid (5)... on excitation of a magnetic field
Implementation Method 2
at least one force-exerting element, for example at least one compression spring (6)... the second force can be the spring force of at least one compression spring (6)
Implementation Method 3
The deformation of the magnetic force/air gap characteristic curves... is generated at respectively constant linked magnetic flux when a magnetic field is excited... a decrease in the magnetic force is achieved in the case of small air gaps and an increase in the magnetic force is achieved in the case of large air gaps
Data Source
AI summary
A method for controlling an electromagnetic brake (1) having a coil carrier (2), a solenoid (5), an armature disc (7), and at least one further force-exerting element. The internal and external poles (3, 4) of the coil carrier each have a front surface with a varying gradient that fits, in a complementary fashion, the front surfaces of the respective internal and external poles (8, 9) of the armature disc. The brake has an air gap (11) which varies in size and forms a stroke region (21). When excitation occurs, the solenoid generates a magnetic force, and the force-exerting element generates an opposing force, wherein the ratio of the solenoid's magnetic force and the opposing force varies at least once between greater than and smaller than one during the movement of the armature disc in the stroke region owing to the variation of the excitation of the solenoid.