Temperature compensating flux ring

A vibration damper operably connected to a suspension system of a motor vehicle comprising:

• a housing defining a piston chamber having magneto-rheological (MR) fluid disposed therein;
• a piston slidably disposed within said piston chamber and being affixed to a piston shaft inserted through said housing;
• said piston including:
• a piston core defining an outer wall and having at least one electric coil coaxially aligned with said piston shaft capable of generating a magnetic field;
• a sleeve encircling said piston core having an inner wall defining an annular fluid passage with said outer wall of said piston core allowing MR fluid to pass therethrough;
• and
• at least one of said inner wall and said outer wall having at least one channel circumscribing said core thereby increasing the distance between said inner wall and outer wall at said channel.

A vibration damper operably connected to a suspension system of a motor vehicle comprising:

• a housing defining a piston chamber having magneto-rheological (MR) fluid disposed therein;
• a piston slidably disposed within said piston chamber and being affixed to a piston shaft telescoping out of said piston chamber;
• said piston including:
• a piston core having a piston wall with an outer diameter coaxially aligned with said piston shaft;
• a sleeve concentrically aligned with said piston core having a sleeve wall with a first inner diameter substantially parallel with said piston wall defining an fluid passage with said piston core;
• at least one electric coil encircling said piston core capable of transmitting a magnetic field defining a magnetic area of said annular passage;
• and
• wherein at least one of said piston wall and said sleeve wall include at least one channel circumscribing said core thereby increasing the distance between said piston wall and said sleeve wall at said channel.