Research on Rolling-Sliding Integrated Auxiliary Bearing and its Application in High Temperature Reactor

The active magnetic bearings (AMB), with the advantages of no friction, no abrasion, no lubrication and active control, is used in the primary helium circulator for high-temperature gas-cooled reactor (HTR). But the magnetic bearing is a complex system, which contains sensor, controller, power amplifier circuit and actuators. Any part of failure is likely to make high-speed rotor off balanced position and fell in the inner ring of the bearing, causing huge impact and fiction heat that may damage the magnetic bearing. Therefore, it is necessary to bring the auxiliary bearing in the magnetic bearing to protect and temporarily support the high-speed rotor. The auxiliary bearings are mainly divided into two categories: rolling bearings and plain bearings. Generally speaking, for rolling bearings, the force of friction is smaller and the heat caused by it is lower during the touchdown. However, it needs to be detected online to ensure that it can work well in emergencies, and the rolling bearings has a smaller load capacity because of the point contact between the ball and the ring. Compared with the rolling bearings, the structure of plain bearings is simple and durable. With a larger load capacity and the advantage of non-contact detection, the plain bearing is gradually becoming a research hot-spot in the field of the auxiliary bearing. But the great friction and inevitable heat are also cannot be ignored. In High temperature gas-cooled reactor demonstration power station (HTR_PM), the work load of helium main fan is very large, once the support of electromagnetic bearing is out of work, the auxiliary bearing need to suffer from a very large drop impact load, which is accompanied by a huge friction fever. Therefore, it is important to develop a rolling-sliding integrated bearing which can bear heavy load and have little friction, combined with the advantages of plain bearings and rolling bearings. And that is an important direction of the development for the main helium pan in high temperature gas-cooled reactor nuclear power plant. This paper establish a simulation model for a horizontal rotor and rolling-sliding integrated auxiliary bearing system. In the case of synchronous rotation of the inner ring with the rotor, the speed of the outer race of the bearing is determined. and based on the main helium fan in HTR-PM, using the finite element analysis software LS-Dyna, the rolling-sliding integrated auxiliary bearing is proposed and the impact force and the MISES stress nephogram when the peak inflation occurred during the first impact and the axial axes displacement curve during rotor drop in the auxiliary bearing are preliminarily simulated in this paper., then certain theoretical reference is provided for the design and engineering application of the rolling-sliding integrated auxiliary bearing.