1. Field of the Invention
The subject invention relates to a steering column assembly for a vehicle.
2. Description of Related Art
The interaction between steering system components and road conditions during vehicle movement can generate mechanical impulses that excite the steering system. For example, the wheels of the vehicle can be induced to turn, which induces a steering shaft and associated steering wheel to turn. Alternatively, vibration can be generated at one position in the steering system during vehicle movement and can be transmitted through the steering shaft to the steering wheel.
The prior art has recognized the issues of undesirable vibration and movement of the steering shaft and steering wheel and has attempted to isolate these forces. One solution is to incorporate rubber or other vibration absorbing materials into the steering shaft. In other words, the steering shaft is split into one or more sections and the material is disposed between the sections such that rotation of the steering shaft must pass through the material. Examples of this solution can be found in U.S. Pat. Nos. 1,572,519, 2,272,900, and 6,733,039. Another solution incorporates a vibration absorbing material between the steering shaft and an outer jacket. Examples of this solution can be found in U.S. Pat. Nos. 4,517,854, 5,538,282, and 5,902,186.
Although these prior art solutions may be somewhat effective in isolating vibration, these solutions suffer from a number of deficiencies. Also, these known solutions are inadequate for creating a desired frictional force against rotation of the steering shaft.