tailieunhanh - Vertical Shaft Plumbness Using a Laser Alignment System

Nhập khẩu dữ liệu của bên thứ ba là một điều cần thiết và không có công cụ thích hợp và kỹ thuật để giúp đỡ khi làm việc trên các cụm lớn, sớm hay muộn, họ trở nên khó sử dụng và người dùng sẽ cảm thấy hệ thống làm chậm như các nguồn lực thấp. | Vertical Shaft Plumbness Using a Laser Alignment System By Daus Studenberg Ludeca Inc. ABSTRACT Traditionally plumbness measurements on a vertical hydro-turbine generator shaft involved stringing a series of wires along the length of the shaft attaching a weight to the end of the wires and then measuring the space from the wire to the shaft using an electronic micrometer. Although this method was inexpensive and has been used for many years it did require access to a long length of the shaft to achieve an accurate resolution. Also measurements involve physically measuring the distance between the wire and the shaft at various elevations on the shaft increasing the amount of time and personnel requirement for the measurement. Ludeca Inc. presents their experience with a laser-based system which replaces the time-consuming wire method. Measurements can now be performed in a fraction of the time it would otherwise take with the wire measurement method. Ludeca s measurement system known as the PERMAPLUMB uses a selfadjusting mechanical mirror always plumb to earth that reflects a class 1 laser beam into a detector. It requires only 14 of axial space along the shaft. The mirror and transducer are attached by a bracket that uses magnets on the turbine shaft. From a single 270-degree shaft rotation the system calculates and displays angularity and corrective moves and provides a statistical quality measurement of the data. A move function allows monitoring of corrections as they are being made. The resolution is better than more accurate than required by NEMA . Adjacent turbines can also continue to operate since the system is insensitive to vibration. Introduction Plumbness is the relationship of a rotating centerline to gravity. It can be thought of as the verticality of a centerline. In practice with vertical hydro shaft measurement it is actually un-plumbness that is being measured since the factor quantified is the difference from perfectly vertical as .