Transmission and Conversion of Energy by Coupled Soft Gears
  Dynamical aspects of coupled deformable gears are investigated to clarify the differences of mechanical properties between the machines consist of hard materials and those of soft materials. In particular, the performances of two functions, the transmission and the conversion of the energy, are compared between the hard and soft gears systems. First, the responses of the coupled gears against a constant torque working on one of gears are focused for two types of couplings; P) a pair gears are coupled, and T) three gears are coupled with forming a regular triangle. In systems with the coupling P), we obtain trivial results that the rotational energy can be transmitted to other gear only if these gears are hard enough. On the other hand, in systems with the coupling T), the transmission of the rotational energy to one of the other gears appears only if these gears are soft enough. Second, we show the responses of this system in which one of gears have contact with a high temperature heat bath and the other gears have contact with a 0 temperature heat bath. With the coupling T), the directional rotations appear in two gears having contact with 0 temperature heat bath. Here, the direction of these rotations change depending on the noise strength. 
Akinori Awazu