Haptic operator control device for a vehicle, and method
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.
1. A haptic operator control device for a vehicle, the control device comprising:
a magnetorheological brake device with a brake housing having a static holder and with at least two brake components wherein one of said brake components is connected rotationally conjointly with said holder and said two brake components are continuously rotatable relative to one another;
said two brake components including a first brake component extending in an axial direction and having a core that extends in the axial direction and that is composed of a magnetically conductive material, and a second brake component having a hollow shell part that extends around said first brake component;
a magnetorheological medium at least partially filling an encircling gap formed between said first and second brake components;
at least one electrical coil accommodated in said brake housing;
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, forming said encircling gap with a varying gap height in a region of said at least one star contour.
2. The haptic operator control device according to claim 1 , wherein at least one of said magnetic field concentrators having a cross-sectional area which tapers toward a distal end.
3. The haptic operator control device according to claim 1 , wherein at least one of said magnetic field concentrators is rounded at a distal end.
4. The haptic operator control device according to claim 1 , wherein said core comprises a multiplicity of arms and/or said shell part comprises a multiplicity of arms forming said magnetic field concentrators, which project radially.
5. The haptic operator control device according to claim 4 , wherein at least one of said arms is surrounded by an electrical coil.
6. The haptic operator control device according to claim 4 , wherein each of a multiplicity of said arms is surrounded by an electrical coil.
7. The haptic operator control device according to claim 1 , wherein said least one electrical coil is wound in the axial direction around said core and is configured to generate a magnetic field in a radial direction.
8. The haptic operator control device according to claim 1 , wherein said at least one electrical coil is wound around said axle and is configured to generate a magnetic field in an axial direction.
9. The haptic operator control device according to claim 8 , wherein said electrical coil is accommodated radially between said core and said shell part.
10. The haptic operator control device according to claim 1 , wherein said electrical coil is fastened at an inside to said shell part or is wound around said core.
11. The haptic operator control device according to claim wherein said at least one star contour is one of at least two star contours accommodated in said brake housing.
12. The haptic operator control device according to claim 11 , wherein said two star contours are accommodated so as to be axially spaced apart from one another.
13. The haptic operator control device according to claim 11 , wherein said at least two star contours have different outer contours.
14. The haptic operator control device according to claim wherein at least one said star contour is formed as a separate annular flange with radially projecting magnetic field concentrators.
15. The haptic operator control device according to claim 1 , wherein at least one said star contour has radially inwardly projecting magnetic field concentrators and is fastened magnetically conductively to said shell part.
16. The haptic operator control device according to claim 1 , wherein said electrical coil is disposed to generate a magnetic field running through said core and said star contour with said magnetic field concentrators and through said encircling gap and a wall of said shell part.
17. The haptic operator control device according to claim 1 , wherein said shell part has a cylindrical inner surface over at least one axial section.
18. The haptic operator control device according to claim 1 , wherein said second brake component is mounted for axial displacement on said first brake component in order to allow volume compensation in an event of temperature changes and/or in an event of leakage.
19. The haptic operator control device according to claim 1 , further comprising a rotary dial or a rotary wheel disposed on said shell part.
20. The haptic operator control device according to claim 1 , wherein said at least one electrical coil is configured to generate magnetic fields having magnetic field strengths of greater than 350 A/m in said gap.
21. A method for generating an increased power density of a brake device with magnetorheological fluid and at least one electrical coil, the method comprising:
providing the brake device with a static brake component and a brake component that moves in rotation about a central axis of the static brake component and that is magnetically in direct contact with said static brake component;
generating a magnetic field with the at least one electrical coil; and
providing contour elements on, and connected rotationally conjointly to, one of the two brake components, and using the contour elements to concentrate the magnetic field to thereby increasing the power density of the brake device.
22. A method for generating a high power density of a brake unit with magnetorheological fluid and at least one electrical coil, the method comprising:
providing the brake unit with a static element and an element that moves in rotation about a central axis of the static element and is in direct magnetic contact with the static element;
generating a magnetic field with the electrical coil; and
concentrating the magnetic field with the elements so as to generate the high power density of the brake device.
23. The method according to claim 22 , wherein the concentrating step comprises drawing carbonyl iron particles contained in the magnetorheological fluid out of the surroundings and concentrating the particles in a magnetic field transition region.