초록 ▼

A yaw damper for a front wheel drive vehicle provides torque transfer between the two non-driven wheels and generates a damping yaw moment in opposition to the current vehicle yaw condition. The yaw damper is passive and includes a mechanical clutch or fluid connection between the two non-driven whe

A yaw damper for a front wheel drive vehicle provides torque transfer between the two non-driven wheels and generates a damping yaw moment in opposition to the current vehicle yaw condition. The yaw damper is passive and includes a mechanical clutch or fluid connection between the two non-driven wheels which transfer yaw correcting torque. The mechanical clutch includes first and second pluralities of interleaved friction disks which are coupled by shafts to respective non-driven wheels. A spring compresses the clutch pack and limits torque transfer between the shafts and wheels to a pre-selected maximum torque. In another embodiment, positive displacement pumps driven by each of the non-driven wheels are connected in series and transmit torque in proportion to the speed difference. In another embodiment, nested shafts include centrifugal clutches which transfer torque in proportion to vehicle speed and difference.

대표청구항 ▼

A yaw damper for a front wheel drive vehicle provides torque transfer between the two non-driven wheels and generates a damping yaw moment in opposition to the current vehicle yaw condition. The yaw damper is passive and includes a mechanical clutch or fluid connection between the two non-driven whe

A yaw damper for a front wheel drive vehicle provides torque transfer between the two non-driven wheels and generates a damping yaw moment in opposition to the current vehicle yaw condition. The yaw damper is passive and includes a mechanical clutch or fluid connection between the two non-driven wheels which transfer yaw correcting torque. The mechanical clutch includes first and second pluralities of interleaved friction disks which are coupled by shafts to respective non-driven wheels. A spring compresses the clutch pack and limits torque transfer between the shafts and wheels to a pre-selected maximum torque. In another embodiment, positive displacement pumps driven by each of the non-driven wheels are connected in series and transmit torque in proportion to the speed difference. In another embodiment, nested shafts include centrifugal clutches which transfer torque in proportion to vehicle speed and difference. to said leadscrew and slidably disposed in said housing. 9. The system set forth in claim 8 wherein said housing comprises an extrusion having multiple internal chambers extending through said extrusion, said piston being disposed in one of said chambers and other of said clambers comprising at least one fluid passage to said one chamber. 10. The system set forth in claim 9 wherein said extrusion has a central chamber in which said piston is slidably disposed and at least one peripheral chamber, and wherein said housing further comprises at least one end member mounted on said extrusion having at least one fluid port and internal passage means connecting said at least one port to at least one of said chambers. 11. The system set forth in claim 10 wherein said control means is disposed in one of said peripheral chambers. 12. The system set forth in claim 11 wherein said control means includes a sensor for monitoring position of said piston in said central chamber. 13. The system set forth in claim 12 wherein said piston includes a magnet, and wherein said sensor includes means for magnetic coupling to said piston through a wall of said extrusion that separates said one peripheral chamber from said central chamber. 14. The system set forth in claim 13 wherein said central chamber and said piston are non-round in lateral cross section. 15. The system set forth in claim 8 wherein said housing has a pair of fluid ports coupled to opposed sides of said piston. 16. The system set forth in claim 8 wherein said cylinder means comprises a housing mounted at each end of said motor with said leadscrew extending into each said housing, a piston in each said housing coupled to an end of said leadscrew, and a fluid port at each said housing coupled to one side of the associated piston. 17. The system set forth in claim 2 wherein said hydraulic actuator comprises: an elongated rack adapted to be connected at opposite ends to steerable wheels of a vehicle, said rack having a series of teeth along a section of its length, a rotatable pinion in mesh with the rack teeth and adapted to be operably connected by a column to a steering wheel of the vehicle so as to receive vehicle operator steering input, said rack extending lengthwise within an elongated housing constructed to form an elongated power cylinder and having thereon spaced apart first and second circular interior portions of reduced diameter defining the axially opposite ends of said power cylinder and having a sealed engagement with the rack in order to close opposite ends of said power cylinder, and a piston carried by said rack within said power cylinder having a sealed engagement with the interior of the cylinder and separating the cylinder into first and second power assist working chambers filled with hydraulic fluid. 18. A power steering apparatus comprising: a hydraulic actuator having a pair of power assist cylinder chambers and operable to generate assisting power, a hydrostatic actuator for supplying pressurized fluid to said power assist chambers, an electric motor for operating said hydrostatic actuator, a control valve mechanism operable by a system controller for bypassing between said pair of power assist cylinder chambers of said hydraulic actuator the pressurized fluid supplied by said hydrostatic actuator, pressure sensors for detecting differential pressure between pressures in said pair of power assist cylinder chambers, and a motor control responsive to the output of said pressure sensors for controlling said electric motor thereby to cause said motor to drive said hydrostatic actuator in accordance with steering wheel position so as to return the differential pressure to a predetermined first value, said hydrostatic actuator comprising a double-acting actuator piston and cylinder unit having a pair of working chambers separated by said actuator piston and respectively communicating with said pair of power assist cylinder chambers, said electric motor being