The parameters of a well designed vehicle steering system include a consistent torque effort at the steering wheel, a crisp and symmetric return to the straight ahead position, and a pleasing on-center feel. Historically, these features were more easily attained with a straight-line placement of the steering column relative to the gear connection.
The trend toward vehicle downsizing, along with new vehicle requirements for crush zones and tighter package restraints, have necessitated the incorporation of multiple universal joint steering systems, thus making the features above more difficult to obtain. Moreover, operating angles continue to increase with the reduction of packaging space and imposed government motor vehicle safety standards.
The solution presented herein introduces a small diameter, simplified double Cardan joint that, unlike multiple joint, high angle, single Cardan systems, will transmit rotational motion at near constant velocity with little or no torque variation, thus approximating the performance of less complex systems of years past.