Research on the Development of Permanent Magnetic Gas Suspension Bearing in ORC Waste Heat Generator

High efficiency permanent magnet generator has been widely used in various applications due to its advantages of simple structure, high reliability, small size and high efficiency. However, under high speed condition, the energy loss of unit volume is increased by the mechanical friction generated for the traditional permanent magnet generator when using mechanical bearings. At the same time, oil and grease are not allowed to be used as lubricants in some ORC special occasions, so non-contact bearings are needed to replace mechanical bearings in high speed permanent magnet generators. The main objective of this paper is to develop a new type of permanent magnet gas suspension bearing and apply it to 200kW ORC waste heat permanent magnet generator. According to the specific condition of ORC waste heat permanent magnet generator to choose the appropriate structure of permanent magnetic bearing and gas bearing, and then considering the theory of porous hydrostatic gas bearing with generator and permanent magnet bearing (PMB) size to design the matching gas bearing. Meanwhile, in order to meet the requirement of strength and life, the 3D printing technology was applied to make the gas bearing liner with bearing which is a pioneer work. Then the whole structure design of the permanent magnet gas suspension bearing and the assemble of the bearing loading the ORC residual heat permanent magnet generator are done systematically. The simulation and experiment show that the development and design of ORC Waste Heat Generator supported by permanent magnet gas suspension bearing satisfy the design requirements.