We discuss the non-equilibrium properties of a thermally driven micromachine consisting of three spheres which are in equilibrium with independent heat baths characterized by different temperatures. Within the framework of a linear stochastic Langevin description, we calculate the time-dependent average irreversibility that takes a maximum value for a finite time. This time scale is roughly set by the spring relaxation time. The steady-state average entropy production rate is obtained in terms of the temperatures and the friction coefficients of the spheres. The average entropy production rate depends on thermal and/or mechanical asymmetry of a three-sphere micromachine. We also obtain the center of mass diffusion coefficient of a thermally driven three-sphere micromachine as a function of different temperatures and friction coefficients. With the results of the total entropy production rate and the diffusion coefficient, we finally discuss the efficiency of a thermally driven micromachine.

我们讨论了由三个球组成的热驱动微机的非平衡特性，这三个球与以不同温度为特征的独立热浴处于平衡状态。在线性随机Langevin描述的框架内，我们计算时间相关的平均不可逆性，该不可逆性在有限时间内取最大值。该时间刻度大致由弹簧松弛时间设定。根据球的温度和摩擦系数获得稳态平均熵生产率。平均熵产生速率取决于三球微机的热和/或机械不对称性。我们还获得了热驱动三球微机的质量扩散系数中心，该中心是不同温度和摩擦系数的函数。