Magnetorheological Brake Star Contour for High Torque
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Solution Overview
Problem
Existing magnetorheological braking devices struggle to generate high braking torque, especially with small diameters, due to limitations in magnetic field concentration and distribution.
Innovation Solution
A magnetorheological braking device with a star contour and magnetic field concentrators that are firmly connected to the core or shell part, allowing for efficient magnetic field concentration and increased braking torque without the need for rotating rolling elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If rolling elements are used in the braking gap to generate braking torque, then braking torque can be generated, but the device requires larger installation space and more complex structure
Solution Approach 1:
The patent removes the rolling elements from the braking gap and replaces them with a star contour directly formed on the core. This extraction eliminates the need for separate rolling components while maintaining the braking function through the star contour's interaction with the magnetorheological medium.
Solution Approach 2:
The star contour is integrated directly into the core structure, merging the functions of the core and the braking surface. This consolidation eliminates the need for separate rolling elements and reduces structural complexity while achieving the same braking effect.
2Volume of moving object
If the diameter of the braking device is reduced, then compactness is improved, but magnetic field concentration becomes insufficient and braking torque decreases
Solution Approach 1:
The star contour creates localized regions of high magnetic field concentration at its points, where the magnetic field lines are densely packed. This local quality enhancement allows small devices to generate sufficient braking torque through concentrated magnetic effects rather than relying on overall device size.
Solution Approach 2:
The star contour introduces radial dimensionality to the magnetic field distribution, creating variable gap heights in the radial direction. This dimensional change enables effective magnetic field concentration and braking torque generation even in compact axial spaces.
3Force
If longer rolling elements are used to increase braking torque, then magnetic field acts over larger area, but magnetic field concentration decreases and braking effect diminishes
Solution Approach 1:
The star contour concentrates the magnetic field at its discrete points rather than distributing it uniformly along a long roller surface. This local quality approach ensures high magnetic field concentration at the interaction points, maintaining effective braking torque generation.
4Device complexity
If stationary magnetic field concentrators are used instead of rotating rolling elements, then device complexity is reduced, but braking torque generation capability may be compromised
Solution Approach 1:
The star contour on the rotating core serves dual functions: it creates the necessary gap variation for magnetorheological medium interaction and simultaneously acts as the magnetic field concentrator. This self-service design eliminates the need for separate stationary concentrators while maintaining braking torque generation.
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 device achieves high braking torque in a small installation space, with stationary magnetic field concentrators providing a significant increase in generated torque, allowing for compact and cost-effective design.
Implementation Method 1
Magnetorheological fluids, for example, contain extremely fine ferromagnetic particles, such as carbonyl iron powder, distributed in an oil. When such a magnetorheological fluid is exposed to a magnetic field, the carbonyl iron particles of the magnetorheological fluid interlink along the magnetic field lines, so that the rheological properties of the magnetorheological fluid (MRF) are significantly influenced depending on the shape and strength of the magnetic field
Implementation Method 2
A star contour with magnetic field concentrators formed thereon is arranged or accommodated between the shell part and the core. These magnetic field concentrators extend (in particular radially and/or axially) into the gap, creating a circumferential gap region in the area of the star contour with a variable gap height
Data Source
Figure 1a~1f
Figure 2a~2c
Figure 3a~3b
AI summary
The invention relates to a magnetorheological braking device (1) with a fixed holder (4) and with two braking components (2, 3), wherein one of the two braking components (2, 3) is fixedly connected to the holder (4) so as not to rotate relative thereto, and wherein the two braking components (2, 3) are continuously rotatable relative to one another, wherein a first braking component (2) extends in the axial direction (20), and wherein the second braking component (3) comprises a shell part (13) of hollow configuration, which extends around the first braking component (2). A peripheral gap (5), which is filled with a magnetorheological medium (6), is configured between the first and the second braking component (2, 3). The first braking component (2) comprises an electric coil (26) and a core (21) which extends in the axial direction (20) and which is made from a magnetically conductive material, wherein the core (21) comprises a main body (33). Magnetic field concentrators (81), which are configured on the core, and/or magnetic field concentrators (81), which are configured on the shell part, protrude into the gap (5), which results in a peripheral gap region (40d) with a variable gap height (40c). The electric coil (26) is wound around at least one section of the core (21) such that a magnetic field (8) of the electric coil (26) runs through the core (21) and the magnetic field concentrators (80, 81) and through the gap (5) into a wall of the shell part (13). The star contour (40) comprises a stacked pack (44) of star plates (40f).