（武漢科技大學 機械自動化學院，湖北 武漢 430081）

摘要：以提高能源利用率為目的，設計了一種擺－球“永動”器。為了減少能量損失，使單擺來回擺動的時間盡量長，在軌道的選擇上，通過對擺線軌道、拋物線軌道和圓弧軌道的效率計算發現，若小球由曲線軌道一側的最高點開始下落，計算小球經過最低點后回復到軌道的另外一側的最高點的高度值，擺線軌跡、拋物線軌跡和圓弧軌跡分別為0.88、 0.77和0.61?？紤]到三個數值相差不大，通過對加工經濟性的分析發現，擺線加工難度大，費用高，圓弧軌道使用普通機床即可達到較好的效果。因此，最終確定圓弧軌道方案。在碰撞過程中為實現能量交換，根據完全彈性碰撞的條件，采用質量相等的兩小球。V型槽與小球的接觸面積小，能量損失小，小球運動也更加穩固。通過比較擺桿和擺線，發現擺桿的計算誤差較大，而選擇擺線連接擺球還可以避免使用軸承。實物模型中，當擺球初始速度為0，以擺拉到水平位置為起始位置下落時，擺球碰撞次數為4次，來回擺動時間為12.8 s.

關鍵詞：能量交換；碰撞；軌道

中圖分類號：TH122        文獻標識碼：A              文章編號：1006－0316 (2012) 04－0060－04

LU Ting-ting，ZENG Yong，XIE Liang-xi，XIONG Wei，CHEN Qian-kang

（Wuhan University of Science and Technology，Wuhan 430081，China）

Abstract：In order to improve the energy utilization, a pendulum-ball perpetuum mobile is designed in this paper. In order to reduce the energy loss and make the simple pendulum swing back and forth as long as possible, in the selection of the orbit, through the calculation of the efficiency ,we find that if the ball begins to fall from the highest point of one side of the curve orbit to the highest point of the other side via the lowest point, the height of the cycloid orbit, the parabolic orbit and the circular arc orbit are respectively 0.88,0.77and0.61. Given that the difference of the three numerical value is not significant, through the analysis of the processing economy of the curve orbit ,we find that the machining of the cycloid orbit is more difficult and expensive than the circular arc orbit, and that the latter one can attain good effect through general-purpose machine tool.So we make a comprehensive consideration and determine the circular arc orbit. In order to realize the energy exchange of the ball, we choose two equiponderant balls on the basis of the requirement of perfect elastic collision. The fact that the contact area of the V-groove and the ball is smaller than others means that its energy consumption is smaller. Furthermore,the ball can move more steadily in the V-groove. Comparing the oscillating bar and the string,we find that the computational error of the oscillating bar is larger than the string and that adopting the string can avoid the use of the bearing. When the ball's initial velocity is 0 in the physical model and pull to put a horizontal position as the starting position whereabouts, the hitting times is four and the time of swing back and forth is 12.8 s.