Vehicle Haptic MR Brake With Star Contours for High Torque
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Solution Overview
Problem
Existing haptic operator control devices for vehicles, particularly those with magnetorheological brake devices, face limitations in generating high braking moments at small diameters due to magnetic field saturation, leading to reduced braking performance.
Innovation Solution
A haptic operator control device with a magnetorheological brake system featuring a star contour with magnetic field concentrators that project radially into an encircling gap between two brake components, allowing for a varying gap height and increased magnetic flux, thereby enhancing braking moment generation without the need for rotatable magnetic field concentrators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the diameter of the brake device is reduced to achieve compact dimensions, then the structural space is reduced, but the braking moment generation capability deteriorates due to magnetic field saturation
Solution Approach 1:
The patent applies local quality by creating magnetic field concentrators with varying gap heights at specific locations within the brake device. Instead of uniformly distributing the magnetic field, the gap height is locally adjusted to concentrate magnetic flux where needed, enabling high braking moments in compact dimensions by optimizing the magnetic field distribution in critical regions
Solution Approach 2:
The patent introduces dimensional variation by creating a three-dimensional magnetic field concentration structure through varying gap heights. This transforms the traditional two-dimensional magnetic field distribution into a three-dimensional concentration pattern, allowing enhanced braking performance in reduced structural space by utilizing vertical gap variation to concentrate magnetic flux
2Force
If the magnetic field strength is increased to improve braking moment, then the braking performance is improved, but magnetic field saturation occurs in the shaft material, limiting further increases
Solution Approach 1:
The patent resolves magnetic field saturation by creating local magnetic field concentrators with varying gap heights. This concentrates the magnetic flux in specific regions rather than uniformly distributing it, allowing the magnetic field to remain below saturation levels in the shaft material while still achieving high braking moments through localized flux concentration in the magnetorheological fluid
Solution Approach 2:
The patent introduces magnetic field concentrators as intermediary structures between the shaft and the magnetorheological fluid. These concentrators with varying gap heights act as mediators that guide and concentrate magnetic flux, enabling efficient magnetic field utilization without causing saturation in the shaft material while maintaining high braking performance
3Force
If longer rollers are used to increase braking moment, then the magnetic field acts over a larger area, but the magnetic field strength decreases due to distribution over the longer surface
Solution Approach 1:
The patent applies local quality by creating varying gap heights at different locations rather than using uniform gap distribution. This concentrates the magnetic field in specific regions with smaller gaps while maintaining longer roller surfaces, achieving both high magnetic field strength in critical areas and extended interaction length for enhanced braking moment
Solution Approach 2:
The patent introduces vertical gap variation as an additional dimension to control magnetic field distribution. By varying the gap height in the vertical dimension while maintaining extended roller length, the magnetic field is concentrated where needed without being diluted across the entire surface area, achieving both high field strength and large interaction area
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 solution enables the generation of high braking moments in a compact structural space, allowing for greater braking torque with reduced dimensions, and provides a scalable and cost-effective design for various vehicle applications.
Implementation Method 1
If such a magnetorheological fluid is subjected to a magnetic field, the carbonyl iron particles of the magnetorheological fluid interlink along the magnetic field lines, such that the rheological characteristics of the magnetorheological fluid (MRF) are influenced considerably (transmissible shear stresses) in a manner dependent on the form and strength of the magnetic field.
Implementation Method 2
at least one star contour arranged between said shell part and said core, said at least one star contour having magnetic field concentrators formed thereon, with said magnetic field concentrators projecting radially into said encircling gap
Data Source
AI summary
A haptic operator control device for a motor vehicle has a magnetorheological brake with a brake component that is fixed to a holder and a brake component that is continuously rotatable relative to the fixed brake component. A first of the brake components extends in an axial direction and has a magnetically conductive core which extends in the axial direction, and a second brake component has a hollow shell part that encircles the first brake component. An encircling gap between the brake components is filled with a magnetorheological medium. An electrical coil is accommodated in the brake housing. At least one star contour with magnetic field concentrators formed thereon is arranged between the shell part and the core. The magnetic field concentrators project radially into the gap to define a varying gap height in a region of the star contour.