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The central support tilting thrust bearing is widely used in the motor-generator unit, and the central support tilting thrust bearing performs poorly compared with the offset bearing. In order to improve the performance of the thrust bearing capable of the bidirectional operation, a spring-supported switching tilting thrust bearing was designed, which could run under offset condition at both clockwise and counterclockwise. In order to verify the reliability of the bearing, we designed a true size thrust bearing test bench and measured the performance parameters of the temperature, pressure, oil film thickness, and power loss of the pad. This article introduces in detail the operation mechanism of the bidirectional offset spring-bed tilting thrust bearing. The bidirectional offset spring-bed tilting thrust bearing structure and the central support bearing structure were compared and tested. The test results of the performance difference of large tilting pad bearings with different structures were obtained. According to the experiment, the spring support structure has good adaptability, and the improved bidirectional offset support bearing not only has higher bearing capacity, but also has better performance in all aspects of temperature rise and loss than the central support bearing. The actual size experiment provides the experimental data for the theoretical calculation of large tilting pad bearings, providing a more accurate basis for the bearing performance and safety assessment.

Thrust-ring-pump is a kind of extreme-low specific speed centrifugal pump with special structure as numerous restrictions from thrust bearing and operation conditions of hydro-generator units. Because the oil circulatory and cooling system with thrust-ring-pump has a lot of advantages in maintenance and compactness in structure, it has widely been used in large and medium-sized hydro-generator units. Since the diameter and the speed of the thrust ring is limited by the generator set, the matching relationship between the flow passage inside the thrust ring (equivalent to impeller) and oil bath (equivalent to volute) has great influence on hydrodynamic performance of thrust-ring-pump. On another hand, the head and flow rate are varying with the operation conditions of hydro-generator units and the oil circulatory and cooling system. As so far, the empirical calculation method is employed during the actual engineering design, in order to guarantee the operating performance of the oil circulatory and cooling system with thrust-ring-pump at different conditions, a collaborative hydrodynamic design and optimization is purposed in this paper. Firstly, the head and flow rate at different conditions are decided by 1D flow numerical simulation of the oil circulatory and cooling system. Secondly, the flow passages of thrust-ring-pump are empirically designed under the restrictions of diameter and the speed of the thrust ring according to the head and flow rate from the simulation. Thirdly, the flow passage geometry matching optimization between thrust ring and oil bath is implemented by means of 3D flow simulation and performance prediction. Then, the pumps and the oil circulatory and cooling system are collaborative hydrodynamic optimized with predicted head-flow rate curve and the efficiency-flow rate curve of thrust-ring-pump. The presented methodology has been adopted by DFEM in design process of thrust-ring-pump and it shown can effectively improve the performance of whole system.

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