초록 ▼

The present invention provides a damping system for use with a mechanism such as a steering system wherein one element moves relative to another element. The system includes a variable volume chamber, a collection chamber, and an inertia track providing fluid communication between the two chambers.

The present invention provides a damping system for use with a mechanism such as a steering system wherein one element moves relative to another element. The system includes a variable volume chamber, a collection chamber, and an inertia track providing fluid communication between the two chambers. A fluid is disposed in the chambers and the inertia track. A compliant tuning member is in fluid communication with the variable volume chamber. The damping system is capable of attenuating vibration at chosen frequencies without adding undesired damping at other frequencies. In the preferred embodiment, the damping system is used to attenuate steering wheel torsional vibration without increasing low frequency damping that would deteriorate steering feel.

대표청구항 ▼

We claim: 1. A damping system for use with a steering system having a steering gear and a tie rod which moves toward and away from the steering gear to cause movement of a vehicle wheel, the system comprising: a boot defining a working chamber, the boot having a first portion connected to the steer

We claim: 1. A damping system for use with a steering system having a steering gear and a tie rod which moves toward and away from the steering gear to cause movement of a vehicle wheel, the system comprising: a boot defining a working chamber, the boot having a first portion connected to the steering gear and a second portion connected to the tie rod such that movement of the tie rod toward the steering gear reduces the volume of the working chamber and movement of the tie rod away from the steering gear increases the volume of the working chamber; an inertia track having a first end in fluid communication with the working chamber of the boot and an opposed second end; a collection chamber in fluid communication with the second end of the inertia track; a fluid disposed in the working chamber, the inertia track, and at least a portion of the collection chamber; and a compliant tuning member in fluid communication with the working chamber, the tuning member being movable to accommodate high frequency changes in the volume of the working chamber. 2. The damping system according to claim 1, wherein the boot is a rolling boot. 3. The damping system according to claim 1, wherein the compliant tuning member is a diaphragm. 4. The damping system according to claim 3, further comprising a diaphragm housing in fluid communication with the working chamber, the diaphragm forming a portion of the diaphragm housing. 5. The damping system according to claim 4, wherein the boot has a bulging stiffness and the diaphragm has a deflection stiffness substantially lower than the bulging stiffness of the boot. 6. The damping system according to claim 1, wherein the compliant tuning member forms at least a part of the boot. 7. The damping system according to claim 6, wherein the compliant tuning part of the boot has a stiffness substantially lower than the remainder of the boot. 8. The damping system according to claim 7, wherein at least a portion of the remainder of the boot is fiber reinforced. 9. The damping system according to claim 1, wherein the collection chamber comprises a chamber at least partially filled with a gas. 10. The damping system according to claim 1, wherein the steering gear has a second tie rod which moves towards and away from the steering gear, the system further comprising: a second boot defining a second working chamber, the second boot having a first portion connected to the steering gear and a second portion connected to the second tie rod such that movement of the tie rod toward the steering gear reduces the volume of the second working chamber and movement of the tie rod away from the steering gear increases the volume of the working chamber; the second end of the inertia track being in fluid communication with the second boot, such that the second boot forms the collection chamber. 11. The damping system according to claim 1, wherein the steering gear has a second tie rod which moves towards and away from the steering gear, the system further comprising: a second boot defining a second working chamber, the second boot having a first portion connected to the steering gear and a second portion connected to the second tie rod such that movement of the tie rod toward the steering gear reduces the volume of the second working chamber and movement of the tie rod away from the steering gear increases the volume of the working chamber; a second inertia track having a first end in fluid communication with the second working chamber and an opposed second end; a second collection chamber in fluid communication with the second end of the second inertia track; a second compliant tuning member in fluid communication with the second working chamber; and a fluid disposed in the second working chamber, the second inertia track, and at least a portion of the second collection chamber. 12. The damping system according to claim 11, wherein the inertia tracks each have a cross sectional area and a length, the area and length of the tracks being the same. 13. The damping system according to claim 11, wherein the inertia tracks each have a cross sectional area and a length, the area and/or lengths of the tracks being different from each other. 14. A damping system for use with a steering system having a steering gear and a tie rod which moves toward and away from the steering gear to cause movement of a vehicle wheel, the damping system being tuned to at least partially damp a chosen frequency, the system comprising: a variable volume chamber in mechanical communication with the steering gear and the tie rod such that movement of the tie rod in a first direction wit respect to the steering gear reduces the volume of the chamber and movement of the tie rod in an opposite second direction with respect to the steering gear increases the volume of the chamber; a collection chamber; an inertia track having a first end in fluid communication with the variable volume chamber and an opposed second end in fluid communication with the collection chamber, the inertia track having a cross sectional area and a length; a fluid disposed in the variable volume chamber, the inertia track and at least a portion of the collection chamber; and a compliant tuning member in fluid communication with the chamber, the flexible tuning member having a deflection stiffness; the cross sectional area and length of the inertia track and the deflection stiffness of the compliant tuning member being chosen such that the system damps movement of the tie rod relative to the steering gear generally at the chosen frequency. 15. A damping system for use with a mechanism having a first element which moves toward and away from a second element, the damping system being tuned to at least partially damp a chosen frequency, the system comprising: a variable volume chamber in mechanical communication with the mechanism such that movement of the first element in a first direction with respect to the second element reduces the volume of the chamber and movement of the first element in an opposite second direction with respect to the second element increases the volume of the chamber, the variable volume chamber having a stroke sufficient to allow displacements of the first element relative to the second element of at least 100 mm; a collection chamber; an inertia track having a first end in fluid communication with the variable volume chamber and an opposed second end in fluid communication with the collection chamber, the inertia track having a cross sectional area and a length; a fluid disposed in the variable volume chamber, the inertia track and at least a portion of the collection chamber, the fluid having a fluid density; a volume of fluid being displaced into or from the variable volume chamber by movement of the first element relative to the second element, the volume displaced per unit of movement being defined as dV/dx; an actual fluid mass for the inertia track being given by the formula; description="In-line Formulae" end="lead"actual fluid mass=(cross sectional area)��(length)��fluid density;description="In-line Formulae" end="tail" the system having a system effective mass given by the formula; description="In-line Formulae" end="lead"system effective mass=((dV/dx)/(cross sectional area))2��actual fluid mass;description="In-line Formulae" end="tail" a compliant tuning member in fluid communication with the chamber, the compliant tuning member having a deflection stiffness and an area; the system having a system effective stiffness given by the formula; description="In-line Formulae" end="lead"system effective stiffness=((dV/dx)/(Area of compliant member))2��deflection stiffness;description="In-line Formulae" end="tail" the system having a resonant frequency given by the formula; description="In-line Formulae" end="lead"system resonant frequency=(system effective stiffness/system effective mass)1/2;description="In-line Formulae" end="tail" the cross sectional area and length of the inertia track and the deflection stiffness of the compliant tuning member being chosen such that the system resonant frequency is generally at the chosen frequency. 16. The damping system according to claim 15, wherein the mechanism is a steering system, the first element is a tie rod, and the second element is a steering gear housing. 17. The damping system according to claim 16, further comprising a boot defining the variable volume chamber, the boot having a first portion connected to the steering gear housing and a second portion connected to the tie rod. 18. The damping system according to claim 17, wherein the boot is a rolling boot. 19. The damping system according to claim 15, wherein the system effective mass is at least 100 times the actual fluid mass. 20. The damping system according to claim 19, wherein the system effective mass is at least 200 times the actual fluid mass. 21. The damping system according to claim 15, wherein the system resonant frequency is in the range of 10-25 Hz. 22. A damping system for use with a mechanism having a first element which moves toward and away from a second element, the damping system being tuned to at least partially damp a chosen frequency, the system comprising: a variable volume chamber in mechanical communication with the mechanism such that movement of the first element in a first direction with respect to the second element reduces the volume of the chamber and movement of the first element in an opposite second direction with respect to the second element increases the volume of the chamber; a collection chamber; an inertia track having a first end in fluid communication with the variable volume chamber and an opposed second end in fluid communication with the collection chamber, the inertia track having a cross sectional area and a length; a fluid disposed in the variable volume chamber, the inertia track and at least a portion of the collection chamber, the fluid having a fluid density; a volume of fluid being displaced into or from the variable volume chamber by movement of the first element relative to the second element, the volume displaced per unit of movement being defined as dV/dx; an actual fluid mass for the inertia track being given by the formula; description="In-line Formulae" end="lead"actual fluid mass=(cross sectional area)��(length)��fluid density;description="In-line Formulae" end="tail" the system having a system effective mass given by the formula; description="In-line Formulae" end="lead"system effective mass=((dV/dx)/(cross sectional area))2��actual fluid mass;description="In-line Formulae" end="tail" a compliant tuning member in fluid communication with the chamber, the compliant tuning member having a deflection stiffness and an area; the system having a system effective stiffness given by the formula; description="In-line Formulae" end="lead"system effective stiffness=((dV/dx)/(Area of compliant member))2 ��deflection stiffness;description="In-line Formulae" end="tail" the system having a resonant frequency given by the formula; description="In-line Formulae" end="lead"system resonant frequency=(system effective stiffness/system effective mass)1/2;description="In-line Formulae" end="tail" wherein the cross sectional area and length of the inertia track and the deflection stiffness of the compliant tuning member are chosen such that the system resonant frequency is generally at the chosen frequency; wherein the stiffness of the variable volume chamber at frequencies substantially below the chosen frequency is less than 50 N/mm.