The objective of this research is to demonstrate the capability of a long stroke linear ferrofluid (FF) stage. This stage is a passive alternative to existing linear aerostatic stages and can be used in low loaded CNC devices, pick and place machines, microscopy or scanner applications. To compete with aerostatic stages the bearing must be repeatable and achieve sufficient stiffness for the application. The effects of ferrofluid trail formation are countered with the use of a ferrofluid reservoir located on the mover. To increase stiffness a specially designed magnet configuration is used. A linear guidance was built with outer dimensions of 180x600x80 mm (WxLxH), a mover of 1.8 kg without actuator and payload having a 430 mm stroke. The load capacity of the stage was measured to be 120 N, with a stiffness of 0.4 N/$\mathrm{\mu }$m. The maximum height delta after a stroke with 1 kg payload and a mover velocity of 0.25 m/s was measured to be less than $\pm 3\mathrm{\mu }\mathrm{m}$, and with 1.75 kg payload and a velocity of 0.5 m/s the height delta was within $\pm 7\mathrm{\mu }\mathrm{m}$. Using a rheometer, it was shown that the effects of evaporation in ferrofluid can be reversed, within certain limits of mass loss, by adding carrier fluid. The damping is shown to be a function of payload and velocity and was measured to be between 2 and 4 N$\cdot$s/m for velocities between 0.2 and 0.5 m/s. In comparison to a linear aerostatic stage it can be concluded that while the linear ferrofluid stage is outperformed in stiffness and out-of-plane repeatability, the ferrofluid stage does not require a continuous supply of air and has lower fabrication tolerances due to the higher fly height. Thus, the linear ferrofluid stage is a cost-effective alternative to a linear aerostatic stage when the stiffness and straightness are of less importance.

这项研究的目的是证明长行程线性铁磁流体（FF）阶段的能力。该平台是现有线性气动平台的被动替代品，可用于低负载CNC设备，拾取和放置机器，显微镜或扫描仪应用中。为了与空气静力级竞争，轴承必须可重复使用，并具有足够的刚度以适应应用。通过使用位于动子上的铁磁储液罐可以抵消铁磁流迹形成的影响。为了增加刚度，使用了专门设计的磁体配置。建立了具有180x600x80 mm（WxLxH）外部尺寸，1.8 kg的动子的线性导轨，不带致动器，有效载荷的行程为430 mm。测得该平台的负载能力为120 N，刚度为0.4 N /$\mathrm{\mu }$米 在有效载荷为1 kg，动子速度为0.25 m / s的情况下，测得的最大高度差小于$\pm 3\mathrm{\mu }\mathrm{米}$，有效载荷为1.75 kg，速度为0.5 m / s，高度差在 $\pm 7\mathrm{\mu }\mathrm{米}$。使用流变仪表明，在一定质量损失范围内，通过添加载液可以逆转铁磁流体中的蒸发作用。所示的阻尼是有效载荷和速度的函数，测得为2至4 N$\cdot$速度在0.2到0.5 m / s之间的s / m。与线性空气静力平台相比，可以得出结论，尽管线性铁磁流体平台在刚度和平面外重复性方面表现出色，但铁磁流体平台不需要连续供气，并且由于较高的飞行阻力而具有较低的制造公差高度。因此，当刚度和直线度不太重要时，线性铁磁流体阶段是线性空气静压阶段的一种经济高效的替代方案。