上机架主要作用是承受来自上导轴承径向力、固定发电机位置、维护发电机机壳、散热，保证各种工况下发电机系统的轴系稳定性。上机架由14条支臂、1个中心体等在现场组装而成。上机架轴向通过14件安装在定子机座上环板处的垂直支墩与定子相连，径向通过14件上机架基础板与混凝土相连,支臂高度为1.1米，起吊重量55吨。

上机架于3月19日开始施工，3月23日完成焊前验收，焊接探伤检测合格率100％，4月6日以优良数据通过业主、监理、厂家的三方联合验收。

为保证此次吊装顺利完成，羊曲项目部组织人员对桥机各关键部位、吊具进行安全技术检查，合理布置挂装位置，保证吊装各环节安全可靠，吊装历时45分钟实现与顶轴顺利对接。

The main function of the upper frame is to withstand the radial force from the upper guide bearing, fix the generator position, maintain the generator housing, heat dissipation, and ensure the shaft stability of the motor system under various working conditions. The upper frame is assembled by 14 supporting arms and 1 central body on site. The upper frame is connected to the stator axially through 14 vertical piers installed on the ring plate of the stator frame, and is connected to the concrete radially through 14 foundation plates of the upper frame. The height of the support arm is 1.1 meters and the lifting weight is 55 tons.

The construction of the upper frame began on March 19, the pre-welding acceptance was completed on March 23, and the pass rate of welding flaw detection was 100%. On April 6, it passed the joint acceptance of the owners, supervisors and manufacturers with excellent data.

In order to ensure the successful completion of the hoisting, the Yangqu project Department organized personnel to carry out safety technical checks on the key parts and spudders of the bridge, rationally arranged the hoisting position, and ensured the safety and reliability of each link of the hoisting. The hoisting lasted 45 minutes to realize the smooth docking with the top shaft.