Magnetorheological fluid damper with multiple annular flow gaps

A damper, comprising:

• a cylinder containing a magnetorheological fluid;
• and
• a piston assembly slidably mounted for reciprocal movement in said cylinder to form a first chamber positioned on one side of said piston assembly and a second chamber positioned on an opposite side of said piston assembly, said piston assembly including a piston core and a magnet assembly adapted to generate a magnetic field, said magnet assembly including a first flux ring positioned concentrically around said piston core to form a first annular flow gap positioned radially between said piston core and said first flux ring, said magnet assembly further including a second flux ring positioned concentrically around said first flux ring to form a second annular flow gap positioned radially between said first flux ring and said second flux ring, said first and said second annular flow gaps being open for substantially unrestricted flow therethrough in both directions between the first and second chambers and sized to permit magnetorheological fluid flowing through said first and said second annular flow gaps to experience a magnetorheological effect affecting the flow of the magnetorheological fluid through said first and said second annular flow gaps.

A damper, comprising:

• a cylinder containing a magnetorheological fluid;
• and
• a piston assembly slidably mounted for reciprocal movement in said cylinder to form a first chamber positioned on one side of said piston assembly and a second chamber positioned on an opposite side of said piston assembly, said piston assembly including a plurality of annular flux rings positioned concentrically to form a plurality of substantially annular flow gaps positioned concentrically to one another, each of said plurality of substantially annular flow gaps formed between opposing surfaces of magnetic material, said piston assembly further including a magnet assembly adapted to generate a magnetic field extending through said plurality of substantially annular flow gaps to cause magnetorheological fluid flowing through said plurality of substantially annular flow gaps to experience a magnetorheological effect affecting the flow of the magnetorheological fluid through said plurality of substantially annular flow gaps, wherein a central portion of each of said flux rings includes a magnetic flux barrier formed of a non-magnetic material.

A damper, comprising:

• a cylinder containing a magnetorheological fluid;
• and
• a piston assembly slidably mounted for reciprocal movement in said cylinder to form a first chamber positioned on one side of said piston assembly and a second chamber positioned on an opposite side of said piston assembly, said piston assembly including a piston core and a magnet assembly adapted to generate a magnetic field, said magnet assembly including a first flux ring positioned concentrically around said piston core to form a first annular flow gap positioned radially between said piston core and said first flux ring, said magnet assembly further including a second flux ring positioned concentrically around said first flux ring to form a second annular flow gap positioned radially between said first flux ring and said second flux ring, said first and said second annular flow gaps sized to permit magnetorheological fluid flowing through said first and said second annular flow gaps to experience a magnetorheological effect affecting the flow of the magnetorheological fluid through said first and said second annular flow gaps, wherein a central portion of each of said first and said second flux rings includes a magnetic flux barrier formed of a non-magnetic material.