Magnetorheological Brake Coil Layout for Higher Torque Density
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Solution Overview
Problem
Existing magnetorheological brake devices struggle to generate a high braking moment, especially at small diameters, due to limitations in magnetic flux distribution and saturation in the central shaft.
Innovation Solution
The device component features a magnetorheological brake device with a stationary mount and at least two brake components, where the electric coil is wound transversely to the axial direction of the first brake component, allowing for a larger core cross-section and increased magnetic field intensity, thereby enhancing braking force generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the magnetic field is closed by the central shaft or passes through it, then the construction is compact, but the generatable braking moment is restricted due to magnetic saturation in the shaft material
Solution Approach 1:
The invention extracts the magnetic field path from the central shaft by providing a separate magnetic circuit with magnetic conductors arranged in the gap between the brake components. This removes the shaft from the magnetic flux path, eliminating the saturation limitation while maintaining compact construction.
Solution Approach 2:
The invention introduces magnetic conductors as intermediary elements in the gap between brake components. These conductors serve as mediators to guide and concentrate the magnetic field lines, enabling high braking moments without requiring the magnetic field to pass through the central shaft.
2Force
If longer rolling members are used to increase braking moment, then the magnetic field acts on a larger area, but the field strength per unit area decreases leading to lower braking efficiency
Solution Approach 1:
The invention applies local quality by concentrating the magnetic field in specific regions through magnetic conductors positioned in the gap. This creates localized high-field-strength zones that act on the magnetorheological fluid, maintaining high field strength per unit area even with extended brake component lengths.
Solution Approach 2:
The invention transitions from a single-dimensional magnetic field path through the shaft to a multi-dimensional magnetic circuit distributed in the gap between brake components. This allows the magnetic field to act on a larger effective area while maintaining intensity through strategic positioning of magnetic conductors.
3Force
If the diameter of the shaft is increased to allow higher magnetic flux, then the braking moment can be increased, but the installation space requirement increases
Solution Approach 1:
The invention nests the magnetic conductors and magnetic circuit within the existing gap between brake components, utilizing the available space efficiently. This allows high magnetic flux to be achieved without increasing the overall installation footprint, as the magnetic circuit is integrated into the existing structure.
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 configuration enables the generation of higher braking forces within the same installation space or achieves identical brake forces with reduced installation space, resulting in improved torque efficiency and scalability.
Implementation Method 1
When such a magnetorheological fluid is impinged by a magnetic field, the carbonyl iron particles of the magnetorheological fluid form a chain along the magnetic field lines so that the rheological properties of the magnetorheological fluid (MRF) are significantly influenced as a function of the shape and intensity of the magnetic field.
Implementation Method 2
The first brake component comprises a core which is made from a magnetically conductive material and extends in the axial direction, and (at least) one electric coil which in the axial direction is wound about the core and defines a coil plane so that a magnetic field of the electric coil extends transversely (to the axial direction) through the first brake component.
Data Source
AI summary
A device component has a magnetorheological brake device with a static holder and with two brake components. A first brake component is rotationally fixedly to the holder and extends in an axial direction. A second brake component has a hollow, rotary part which is rotatable about the first brake component. An encircling gap between the first and second brake components is filled with a magnetorheological medium. The first brake component has a core of magnetically conductive material which extends in the axial direction. An electrical coil is wound axially around the core and spans a coil plane. A magnetic field of the coil extends transversely through the first brake component. A maximum outer diameter of the electrical coil in a radial direction within the coil plane is greater than a minimum outer diameter of the core in a radial direction transversely to the coil plane.