Alignment of the shaft
<<Engine construction and Operation
This is done by piano wire or by optical sighting methods.
Piano wire measurement
a. A 0.5 mm piano wire is stretched along each side of the Bedplate, between pre-defined fixed points.
a. A 0.5 mm piano wire is stretched along each side of the Bedplate, between pre-defined fixed points.
b. The wire is tensioned by a specified load. (49 kP).
c. At each main bearing, the vertical and horizontal distances are measured, between the piano. wire and the machined faces of the Cross girders.
d. Changes in position will reveal misalignment.
Optical sighting.
This is widely used by Classification societies, for checking the alignment of the Stern-tube and engine bearings.
A sighting telescope is used, which is supported on a table with a series of sighting discs, each with a centre hole, located in the stern-tube housing. The Telescope incorporates a Zoom lens, to make it possible to focus or read the whole series of sighting marks.
By micrometre adjustment, the misalignment can be measured. A laser beam may also be used to easily check the sighting axis.
c. At each main bearing, the vertical and horizontal distances are measured, between the piano. wire and the machined faces of the Cross girders.
d. Changes in position will reveal misalignment.
Optical sighting.
This is widely used by Classification societies, for checking the alignment of the Stern-tube and engine bearings.
A sighting telescope is used, which is supported on a table with a series of sighting discs, each with a centre hole, located in the stern-tube housing. The Telescope incorporates a Zoom lens, to make it possible to focus or read the whole series of sighting marks.
By micrometre adjustment, the misalignment can be measured. A laser beam may also be used to easily check the sighting axis.
Comments
Post a Comment