Evaluation of a magnetic gear for air‐cooled condenser applications

Abstract

In high-power industrial applications such as air-cooled condenser fans, excessive mechanical gear failures highlight a need to investigate possible alternatives. In this study, the concentric magnetic gear (CMG) is evaluated as a potential replacement for traditional mechanical gear. For a more objective comparison between the CMG and mechanical gear, a CMG is optimally designed in accordance with the performance specifications of an existing mechanical gear. The design is further refined for performance improvements taking into account mechanical strength requirements. Based on the design a CMG prototype is manufactured and experimentally evaluated against its mechanical counterpart under the same operating conditions. The performance of both gears achieved efficiency in the mid 90% range. The mechanical gear slightly outperformed the CMG under rated operating conditions. The large unbalanced magnetic forces within the CMG are likely responsible for the larger than expected no-load losses. With the advantage of overload protection, reduced maintenance requirements, the CMG could be a valid replacement for the mechanical gear.

A review on the field‐modulated magnetic gears: Development status, potential applications, and existent challenges

“…The indicator C T reflecting severity of cogging torque in a PM machine [106][107][108][109] is usually applied to evaluate the torque ripple in an FMMG. The value of C T is the greatest common divisor of 2P 1 (or 2P 2 ) and P 3 [110][111][112]. It can be found that an FMMG with fractional gear ratio usually has a C T much smaller than that with integer gear ratio.…”

Load Angle of Flux Modulated Magnetic Gears

“…The finite element modelling of an FMMG can also be made simpler by selecting appropriate initial angles. Since magneto-static FE solution is usually used to model an FMMG, a common practice is to position the gear components so that the peak torque can be realized [23], which means δ g = 90 • . An easy way to realize this is to align the PM pole axis of a rotor disc with that of a modulator pole-piece and then position the PM pole axis of the other rotor disc with an offset mechanical angle of 90 • /p L,H as illustrated in Figure 8.…”

Analysis and Design of Novel Structured High Torque Density Magnetic-Geared Permanent Magnet Machine

“…The proposed structure overcomes the drawbacks of the previous structures and can achieve low-speed high-torque operation. Furthermore, the electric continuous variable transmission system (E-CVT) can be achieved with the proposed structure, which is useful in a broad spectrum of industry and application [41], such as hybrid electric vehicles (HEVs) [42][43][44] and marine [45].…”