Magnetorheological transmission apparatus
A transmission apparatus has two components that move in translation relative to one another and a coupling gap between the components containing a magnetorheological medium. The gap is formed and sealed outwardly at first and second ends so that the magnetorheological medium remains in the coupling gap as a sort of controllable friction lining, irrespective of a coupling between the components, in accordance with the magnetic field applied in the coupling gap. One of the components has plurality of radially extending arms that carry a magnetic field generation device. Each magnetic field generation device has an electric coil with a least one winding extends completely beside the central axis and at a distance therefrom. Different poles of the magnetic field generation devices are provided at the adjacent ends of adjacent arms of a component. The coupling gap is connected to a reservoir of magnetorheological medium.
1. A transmission apparatus, comprising:
at least two components to be coupled and configured to move in translation along a central axis relative to one another, a first of said at least two components being a piston cylinder and a second of said at least two components being a piston head, said piston head and said piston cylinder forming at least one coupling gap between a radially outer wall of said piston head and an inner wall of said piston cylinder;
a magnetorheological medium disposed in said coupling gap;
said coupling gap being outwardly sealed in a direction of translation at a first end and a second end of said piston head to retain said magnetorheological medium in said coupling gap as a controllable friction lining, irrespective of a coupling between said at least two components, and to influence the coupling via shear forces between said at least two components, in accordance with a magnetic field applied in said coupling gap;
said cylinder head being formed with a plurality of radially extending arms;
magnetic field generation devices for generating a magnetic field in said coupling gap to thereby influence a coupling between said at least two components;
said magnetic field generation devices each including an electric coil with at least one winding on at least some of said arms, each said winding extending completely next to the central axis and at a spacing distance from the central axis, said magnetic field generation devices having mutually different magnetic poles at mutually adjacent ends of adjacent arms of at least one of said components, with each of said arms that carry an electric coil having a magnetization with a magnetic South pole and a magnetic North pole, respectively, mutually adjacent said arms having an opposite magnetization in a radial direction, and said ends of said arms having alternating magnetic South and North poles in a circumferential direction; and
a reservoir with magnetorheological medium connected to communicate with said coupling gap.
2. The transmission apparatus according to claim 1 , wherein said at least two components include an inner component and an outer component disposed to at least partially surround said inner component.
3. The transmission apparatus according to claim 1 , which comprises a spring device disposed to generate a counterforce when said two components are deflected in at least one direction.
4. The transmission apparatus according to claim 1 , wherein one or said components is received on a coupling part and is movable via a free stroke relative to the coupling part.
5. The transmission apparatus according to claim 1 , wherein said coupling gap is one of a plurality of coupling gaps distributed over a periphery of the component.
6. The transmission apparatus according to claim 1 , wherein said magnetorheological medium in said coupling gap is subject, in a rest state, substantially to ambient pressure or slight overpressure.
7. The transmission apparatus according to claim 1 , wherein said coupling gap containing at least one pressure compensation device.
8. The transmission apparatus according to claim 7 , wherein said pressure compensation device comprises at least one groove formed along said coupling gap.
9. The transmission apparatus according to claim 7 , wherein said pressure compensation device comprises at least one channel formed to connect one end of said coupling gap to another end of said coupling gap.
10. The transmission apparatus according to claim 1 , wherein said at least one magnetic field generation device includes a permanent magnet.
11. The transmission apparatus according to claim 10 , wherein a magnetic field of said permanent magnet is influenced via an associated electric coil.
12. The transmission apparatus according to claim 11 , wherein the magnetic field of said permanent magnet is configured to vary continuously and/or to be changed permanently via short pulses of the electric coil.
13. The transmission apparatus according to claim 2 , wherein a length of said inner component is greater than a diameter of said inner component ( 2 ).
14. The transmission apparatus according to claim 1 , which further comprises elements selected from the group consisting of seals, scraper rings, and guides enabling a linear relative movement of said at least two components.
15. The transmission apparatus according to claim 1 , wherein said magnetorheological medium is a suspension of ferromagnetic particles in a medium selected from the group consisting of oil, glycol, and grease.
16. The transmission apparatus according to claim 15 , wherein said medium contains stabilizers.