/g120Type C shows an arrangement with four different magnetic wheels, in which Wheel2 and Wheel3 are  mechanically fixed and mounted on a common, single wobbling wheel Wh2-3. In contrast to the clutch setup of Type B, the magnetic wheel pair Wh3-Wh4 acts also as a magnetic gearing stage. The whole magnetic setup of Type C provides the possibility of generating extremely high reduction ratios with a squared ratio at the most, if compared to Type A and Type B. All three types of MWG benefit from a ripple-free smooth output rotation. For space applications, Type A  and Type C are the candidates of interest:  /g120Type A is characterized by one single magnetic coupling between Wheel1 and Wheel2, resulting in maximized torque stiffness, as well as torque density. As MWG can be easily scaled, it is a good  choice for gear stages providing strong and powerful output shaft motion.  /g120Type C benefits from the potential of extremely high reduction ratios in only one single gear stage, and is useful as a small and compact first gear stage for high speed reduction.   General Characteristics of MWG New properties must be considered when using magnetic gears. Most of these properties are highly  favorable and are described in brief below. Some of these are related only to MWG. /g120High precision: Magnetic systems in general are known for their extremely precise operation. Because  of the absence of mechanical interaction, MWG deliver constant precision in both low and high load  cycles. Mechanical backlash is approximately an order of magnitude less than in conventional precision gears.  /g120Abrasion free: As it is friction free, MWG perform consistently without lubrication. /g120Overload friendly:  At overload, the magnetic transmission acts naturally as a clutch, but remains fully  functional. The elasticity avoids unnecessary stress to related components. The safety clutch is an extremely reliable component and also works without electronics. Hitting an emergency hard end stop  after the failure of some control or due to excessive vibrational loads may not result in the degradation  of the performance of a mechanism. /g120Highly efficient: Magnetic gearboxes offer highly economical energy transfer. Energy conversion is practically seamless: losses via rolling friction and low magnetic hysteresis phenomena are minimal in  operation. /g120High transmission ratio: Because of the unique concept of MWG, only one gear stage is necessary to  achieve high transmission ratios (Type A) or even extremely high ratios (Type C).  /g120Lifetime: All characteristics are quite constant all over the estimated life cycle and ageing effects are  predictable. This is a new feature for gears. Lifetime is only dependent on the lifetime of bearings and not on wear and tear. /g120Temperature operating conditions: One temperature limit for magnetic systems is the Curie  temperature (Tc), in which a material's permanent magnetism changes to induced magnetism. Motors, steppers and also magnetic gears with permanent magnets are affected by this temperature and will lose their permanent magnetism at temperatures exceeding the Tc limit. The Tc depends mainly on the  composition of materials with different properties and is a material property.  /g120High-torque capability: The MWG mechanism takes advantage of a constant air gap over the entire  active area, which makes it superior to other magnetic concepts (Table 1). The result is a compact  design with maximized torque, a crucial precondition for lightweight design. /g120Elasticity: The inherent elasticity caused by the magnetic transmission in a powertrain can be very  desirable, for example for compliant robotic applications. For other applications such as rigid structures, elasticity may be unacceptable. However, elasticity is a design target and can be influenced within  certain limits. Recently, tremendous progress has been achieved (Table 1) by enhancing the torsional  stiffness of the output shaft.  178