LamaLo Technology Inc.
Propulsion
Shaft Vibration
Marine propulsion shaft vibration
measurement and analysis is a core part of LLT’s business. With respect to
existing vibration problems, we take a Systems Engineering approach. All
aspects of the shaftline vibration and alignment are investigated by using a
combination of analytical modeling, on-site measurements, documentation review,
and analysis of the operating environment, bearing/seal design and shipyard
construction practices. Documented case studies and previous experiences are
referenced in the assessment. A least-cost solution is sought. The
Theoretical
Modeling
A formal Engineering Shaftline Vibration Analysis Report is
produced, and includes the following:
Description
of modeling technique and parameters used in the analysis
Natural
Frequencies of Vibration (Torsional, Axial, and Lateral (Whirling)
Vibratory
stresses under all operating conditions. Forced-damped response analysis will
be conducted, if required
Recommendation
for design/equipment/operational changes, if necessary
Comparison
of vibratory stresses to acceptable limits to demonstrate compliance
Measurements
Measurement programs can
include any are all of propulsion shaft torsional, axial, and lateral
vibrations. Shaft torque and thrust are measured using strain gauges, and the
shaft run-out is measured using non-contacting displacement transducers
(proximity probes). Shaft RPM can also be measured. Time domain data is
collected over the full operating range of the system. In most cases, at a
minimum vibration measurements are taken under the following operations:
Steady
Acceleration: Idle speed to full RPM.
Free-Route
at constant speeds: 10 or more equal speed increments
Hard
Turns to Port and Starboard
Crash
Stop
LLT uses the state-of-the-art
instrumentation and software to conduct propulsion shaftline vibration
measurements. The instrumentation includes digital telemetry systems, weldable
strain gauges, and proximity probes. The data acquisition and analysis is done
at near real time on a Lap Top PC, using the most advanced software available.
Analysis and Reporting
Preliminary results
are provided on-board the vessel. This includes an assessment as to the
severity of the vibration and if further testing is required. The measured
vibrations are compared to the vibration standards/criteria. Criteria that are
exceeded are further investigated and the potential cause and recommended
action are provided. A formal Engineering report is submitted within two weeks
of the completion of the tests.
COST
Fixed-price or cost plus quotes are
provided.