A New Concept in Aircraft Undercarriages (Reduction of Longitudinal Impact Force) 2001-01-2962
The author proposes a new principle of suspension system. First, a new shock isolation method prevents sudden sharp jolts and enables a body to continue in motion as before, by transforming linear motion into circular motion. This method reduces abrupt deceleration and impact force. Next, we examined the gravity spring action of a pendulum as a new vibration isolation method. Because the pendulum generates longitudinal vibration, it has isolation effect against the longitudinal vibration input.
Application of this new principle to aircrafts, automobiles, motorcycles, and even to bicycles and wheelchairs, overcomes the limitations of current technology. This study focused on two as-yet-unresolved safety problems of aircraft undercarriages. One is acceleration impact on the wheels; the other is collision with an obstacle on the runway.
The moment the wheel contacts the runway at high speed, horizontal linear motion of the wheel is transformed to circular motion, moderating sudden change in horizontal velocity. Controlling generation of acceleration impact thus reduces tire smoking and excessive wear.
Meanwhile, if the wheel strikes an object lying on the runway while rolling at high speed, longitudinal spring action of the suspension swings the wheel rearward as it passes over the obstacle. The impact force is reduced, substantially reducing the danger of tire rupture.