Improving the Shaft Alignment Process

Accurately aligning vertical shafts in hydro turbine-generator units requires precise measurements, skilled personnel, and the ability to make sound engineering judgments. Hydro Tasmania shares ideas for improving the alignment process.

By Enes Zulovic

Shaft alignment of a vertical hydro turbine-generator unit is a crucial yet highly specialized technical skill.

Accurate shaft alignment requires precise measurements and calculations. In theory, alignment is a straightforward process. However, in actual applications, it is often compounded by out-of-plumb shafts, guide bearing misalignment, thrust bracket deflections, or alkali-aggregate reaction – just to name a few of the challenges. These challenges can produce considerable delays and unsatisfactory results in alignment work.

Based on experiences at Hydro Tasmania, I offer several ideas and guidelines for improving the process of aligning vertical shafts in hydro turbine-generator units.

Improving the alignment process

The process of aligning a shaft on a turbine-generator unit involves several steps. This includes determining an alignment procedure; establishing alignment tolerances; calculating and visualizing alignment data; and deciding when to check the accuracy of the alignment.

In the following sections, I offer ideas for improving each step in the process.

Determining the alignment procedure

For most project owners, alignment of a vertical shaft of a hydro unit involves:

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