Magneto-rheological damper with grooved fluid passages
AssigneeDelphi Technologies, Inc.
InventorSaiman Lun
Life of this patent
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Abstract
Performance of a vehicle damper utilizing a Magneto-Rheological (MR) fluid is enhanced through use of a piston having grooves in the walls of a magnetic flux path portion of a fluid flow passage through the piston. The grooves result in a focusing and intensification of the magnetic flux emanating from the corners of the grooves, to thereby intensify the magnetic flux impressed across the fluid flow passage and cause a greater degree of change in viscosity of the MR fluid flowing through the passage than is achievable in prior MR dampers having smooth-walled fluid flow passages.
Claims20
A piston adapted for reciprocating motion along an axis within a working chamber containing a magneto-rheological (MR) fluid therein of a cylinder tube of a damper, the piston comprising:
- a piston body defining a first and a second face and a fluid flow passage extending through the piston from the first to the second face for directing a flow of MR fluid along a flow direction through the fluid flow passage as the piston reciprocates in the working chamber;
- and
- an electromagnetic element within the piston body defining a wall forming a magnetic flux path portion of the fluid flow passage for directing magnetic flux through the wall and the fluid flow passage in a direction generally transverse to the flow direction, the wall including a groove therein extending in a direction generally transverse to the flow direction through the magnetic flux path portion of the fluid passage for intensifying the magnetic flux passing in a direction transverse to the flow direction through the wall and the magnetic flux path portion of the fluid flow passage.
A damper comprising:
- a cylinder tube defining an axis and a working chamber extending along the axis for containing a magneto-rheological (MR) fluid therein;
- and
- a reciprocating piston slidably disposed in the working chamber and including a first and a second face and a fluid flow passage extending through the piston from the first to the second face for directing a flow of MR fluid along a flow direction through the fluid flow passage as the piston reciprocates in the working chamber;
- the piston having an electromagnetic element defining a wall forming a magnetic flux path portion of the fluid flow passage for directing magnetic flux through the wall and the fluid flow passage in a direction transverse to the flow direction, the wall including a groove therein extending in a direction generally transverse to the flow direction through the magnetic flux path portion of the fluid flow passage for intensifying the magnetic flux passing in a direction transverse to the flow direction through the wall and the magnetic flux path portion of the fluid flow passage.
A damper comprising:
- a cylinder tube defining an axis and a working chamber extending along the axis for containing a magneto-rheological (MR) fluid therein;
- and
- a reciprocating piston slidably disposed in the working chamber and including a piston body defining a first and a second axial face of the piston;
- a magnetic core disposed about the axis within the piston body, adapted for receiving a coil, and having a radially outer cylindrical wall thereof extending axially beyond the coil and defining one or more circumferential annular grooves therein;
- a coil attached to the core for generating a magnetic flux field emanating from the core;
- and
- a flux ring disposed within the piston body about the core in a spaced relationship thereto, to form an annular fluid passage between the radially outer cylindrical wall of the core and the flux ring for directing a flow of MR fluid through the fluid passage in a flow direction generally parallel to the axis as the piston reciprocates in the working chamber;
- whereby the core and flux ring in combination define a magnetic flux path portion of the fluid flow passage for directing magnetic flux through the cylindrical wall and the fluid flow passage in a direction transverse to the flow direction, with the one or more grooves in the core extending in a direction generally transverse to the flow direction through the magnetic flux path portion of the fluid flow passage for intensifying the magnetic flux passing in a direction transverse to the flow direction through the cylindrical wall and the magnetic flux path portion of the fluid flow passage.
Dependencies are inferred from the claim text.