Patent ID: 6149142
Filing Date: 2000-11-21
Classification: B60G

Abstract:
A pneumatic suspension system for a vehicle, first and second axles and a frame, the vehicle frame having a frame beaming frequency, comprising:a first pneumatic spring connected to the first axle and the frame and being subjected to input vibrations from the first axle, the first pneumatic spring containing pneumatic fluid;a second pneumatic spring connected to the second axle and the frame, the second pneumatic spring containing the pneumatic fluid; anda pneumatic conduit in fluid communication with the first and second pneumatic springs, the pneumatic conduit containing the pneumatic fluid therein and being configured to allow the pneumatic fluid to move between the first and second pneumatic springs, the pneumatic fluid in the pneumatic conduit having a resonant frequency in the range of approximately 8.5 to 17.5 Hertz, inclusive, and the first and second pneumatic springs and the conduit define a system having a variable stiffness with a minimum spring stiffness when the input vibration has a frequency substantially corresponding to the frame beaming frequency, and wherein the first pneumatic spring has an internal volume, and the pneumatic conduit has a length and a cross-sectional area, the pneumatic conduit being shaped and sized so the resonant frequency of the pneumatic fluid therein is approximately equal to251.multidot.(A/(V.multidot.L)).sup.1/2, wherein:A=cross sectional area of the pneumatic conduit;V=internal volume of the first pneumatic springs; andL=length of the pneumatic conduit, where the units of measure are in feet.