Stabilizer bar with variable torsional stiffness

• US 20040217569A1
• Filed: 12/18/2003
• Published: 11/04/2004
• Est. Priority Date: 05/01/2003
• Status: Active Grant

• Current Assignee: The Timken Company
• Original Assignee: The Timken Company
• Inventors: Gradu, Mircea, Schlernitzauer, Timothy L.
• Granted Patent: US 7,207,574 B2
• Time in Patent Office: Days
• US Class Current: 280/124.107
• CPC Class Codes: B60G 21/0555 including an actuator inducing vehicle roll
• CPC Class Codes: B60G 21/0558 including means varying the stiffness of the stabiliser B60G21/0556 takes precedence
• CPC Class Codes: B60G 2202/22 Rotary Damper
• CPC Class Codes: B60G 2500/02 Supply or exhaust flow rates; Pump operation
• CPC Class Codes: F16F 1/16 Attachments or mountings F16F1/145 takes precedence; mounting means for vehicle stabiliser bars B60G21/0551
• CPC Class Codes: F16F 9/53 Means for adjusting damping characteristics by varying fluid viscosity, e.g. electromagnetically F16F13/30 takes precedence; brakes comprising a medium with electrically or magnetically controlled friction F16D57/002; electrorheological fluids per se C10M171/001; magnetorheological fluids per se H01F1/447
• CPC Class Codes: F16F 9/535 Magnetorheological [MR] fluid dampers springs comprising magnetorheological [MR] elastomers F16F1/361

Abstract

A stabilizer bar for controlling the roll of an automotive vehicle has left and right sections, each provided with a torsion rod and a torque arm. The torsion rods are aligned along a transverse axis and attached to a structural component of the vehicle, while the torque arms are connected to the left and right control arms of the vehicle'"'"'s suspension system. In addition, the bar has a coupling between the torsion rods of the two sections for controlling the torsional stiffness of the bar. The coupling includes a rotor fitted to one of the torsion rods and a housing fitted to the other torsion rod, with the housing receiving the rotor, such that a cavities exist between the rotor and housing. Both the rotor and housing carry vanes, that alternate so that the vanes of the rotor are located between the vanes of the housing. The cavities contain a magneto-rheological fluid. The bar also includes an electrical coil controls the viscosity of the fluid either at the coupling or at a valve located remote from the coupling, but in either place, such that the variations in the viscosity of the fluid control the torsional stiffness of the stabilizer bar.

Claims

1. A stabilizer bar for an automotive vehicle, said bar comprising:

first and second torsion rods which are aligned along an axis;

a coupling including first and second coupling members attached to the first and second torsion rods, respectively, such that the rods can rotate relative to each other about the axis, the members defining cavities and having formations which are exposed to the cavities;

a fluid that is at least in part is rheological, the fluid occupying at least the cavities to enable torque to transfer between the members; and

means for varying the viscosity of the fluid where it is rheological such that the viscosity of the fluid controls the magnitude of the torque transferred between the members.

2. A stabilizer bar according to claim 1 wherein the fluid where it is rheological is in the cavities.

3. A stabilizer bar according to claim 2 wherein the first coupling member is a rotor and the second coupling member is a housing which surrounds the rotor;

and wherein the rotor and housing have a common axis which coincides with the axis of the rods.

4. A stabilizer bar according to claim 3 wherein the formations on the rotor are vanes which project outwardly away from the axis and the formations on the housing are vanes which project inwardly toward the axis and into spaces between the vanes on the rotor.

5. A stabilizer according to claim 4 wherein the housing has arcuate surfaces from which the vanes of the housing project and toward which the vanes of the hub extend.

6. A stabilizer bar according to claim 5 wherein the hub has arcuate surfaces from which the vanes of the rotor project and toward which the vanes of the housing extend.

7. A stabilizer bar according to claim 6 wherein at least some of the vanes and arcuate surfaces toward which they extend are spaced sufficiently apart that the fluid can pass between those vanes and arcuate surfaces, yet such that the flow is restricted.

8. A stabilizer bar according to claim 6 wherein the vanes and the surfaces toward which they project are close enough to form fluid barriers which substantially prevent the flow of the fluid between them.

9. A stabilizer bar according to claim 8 wherein the rheological fluid is responsive to magnetic fields;

and further comprising a valve located remote from the cavities in the coupling and having first and second chambers and a restrictor separating the chambers, the first chambers being in communication with each cavity of the coupling or one side of the rotor vane for that cavity and the other chamber of the valve being in communication with each cavity on the other side of the rotor vane for that cavity, the restrictor permitting a restricted amount of fluid to flow between the chambers, and an electrical coil for varying the viscosity of the rheological fluid in the chambers, whereby the volume of fluid transferred between the chambers and the torque transferred between the rotor and housing of the coupling is controlled.

10. A stabilizer bar according to claim 9 wherein the coil is located in the restrictor.

11. A stabilizer bar according to claim 1 wherein the rheological fluid is responsive to magnetic fields, and wherein the means for varying the viscosity of the rheological fluid is an electric coil.

12. A stabilizer bar according to claim 11 wherein the housing includes a wall that surrounds the rotor;

and wherein the coil surrounds the wall.

13. A stabilizer bar according to claim 1 wherein the first and second torsion rods are separate and rotate relative to each other.

14. A stabilizer bar according to claim 1 wherein the first and second torsion rods are unified;

wherein the unified rods extend through the coupling; and

wherein the first and second coupling members are attached to the unified torsion rod remote from the cavity containing the rheological fluid so that the unified rod can twist in the region between which it is attached to the coupling members.

15. In combination with a structural component of an automotive vehicle, which further includes left and right control arms pivoted on the structural component about axes that extend generally longitudinally of the vehicle, wheel ends that are connected to the control arms remote from the axes about which the control arms pivot, a stabilizer bar for reducing roll of the structural component in turns, said bar comprising:

left and right sections, each having a torsion rod and a torque arm, the torsion rods of the two sections being aligned along an axis that extends transversely of the vehicle and being attached to the structural component such that the sections can rotate relative to the structural component about the axis, the torque arm of the left section extending from the torsion rod of the left section and remote from that torsion rod being attached to the left control arm, the torque arm of the right section extending from the torsion rod of the right section and remote from that torsion rod being attached to the right control arm;

a coupling located between the left and right sections and including a left coupling member attached to the torsion rod of the left section and a right coupling member attached to the torsion rod of the right section, the left and right coupling members forming at least one cavity and having formations which are exposed to the cavity;

a magneto-rheological fluid in the cavity; and

an electrical coil that produces a magnetic field that passes through the cavity and controls the viscosity of the rheological fluid.

16. The combination according to claim 15 wherein one of the coupling members is a rotor and the other coupling member is a housing that surrounds the rotor.

17. The combination according to claim 16 wherein the formations on the rotor are vanes which project outwardly away from the transverse axis;

and wherein the formations on the housing are vanes which project inwardly toward the axis and into spaces between the vanes and the rotor.

18. The combination according to claim 16 wherein the coil surrounds the housing.

19. The combination according to claim 15 wherein the torsion rods of the left and right sections are detached.

20. The combination according to claim 15 wherein the torsion rods of the left and right sections are unified and pass through the coupling;

wherein the left coupling member includes a tubular extension which extends away from the cavity and receives the torsion rod of the left section;

wherein the right coupling member includes a tubular extension which extends away from the cavity and receives the torsion rod of the right section;

wherein the tubular extensions of the left and right members are secured to the torsion rods of the left and right sections, respectively, remote from the cavity.

22. The combination according to claim 20 wherein one of the coupling members is a rotor and the other coupling member is a housing that surrounds the rotor.

21. In combination with a structural component of an automotive vehicle, which further includes left and right control arms pivoted on the vehicle about axes that extend generally longitudinally of the vehicle, wheel ends that are connected to the control arms remote from the axes about which the control arms pivot, a stabilizer bar for reducing roll of the structural component in tums, said bar comprising:

left and right sections, each having a torsion rod and a torque arm, the torsion rods of the two sections being aligned along an axis that extends transversely of the vehicle and being attached to the structural component such that the sections can rotate relative to the structural component about the axis, the torque arm of the left section extending from the torsion rod of the left section and remote from that torsion rod being attached to the left control arm, the torque arm of the right section extending from the torsion rod of the right section and remote from that torsion rod being attached to the right control arm;

a coupling located between the left and right sections and including a left coupling member attached to the torsion rod of the left section and a right coupling member attached to the torsion rod of the right section, the left and right coupling members forming at least one cavity and having formations which are exposed to the cavity such that the cavity has first and second sides,

a valve located remote from the cavity and having first and second chambers and a restrictor located between the chambers for permitting a restricted flow of fluid between the chambers, the first chambers being in communication with the first side of the cavity in the coupling and the second chamber being in communication with the second side of the cavity;

a coil for producing a magnetic field at the restrictor of the valve;

and a magneto-rheological fluid in the cavity of the coupling and the chambers of the valve.

23. The combination according to claim 21 wherein the formations on the rotor are vanes which project outwardly away from the transverse axis;

and wherein the formations on the housing are vanes which project inwardly toward the axis and into spaces between the vanes and the rotor.