Mar 15, 2016 this video is intended to guide a user through the shaft alignment process for a typical mid engine, direct drive tournament ski boat. Nov 08, 2017 propeller line in service condition to be within specified limits. Disasseinble propeller shaft joint using follow ing procedure. The dnv gl shaft alignment class notations and revised main class rules for single stern tube bearing installations introduce additional focus on the impact of transient hydrodynamic propeller downwardacting bending moments, which are induced in turning conditions at mcr speed, on the aft most propeller shaft bearing. Propulsion shaft alignment method and analysis for surface. The advanced tools of the editor will direct you through the editable pdf. Pdf specifics of shafting alignmentfor ships in service. For instance, if the inner diameter of the shaft log is 1. Shaft alignment definition most shipboard configurations of shafts and bearings are likely to be aligned when some or all of the centrelines of the bearings are offset from the theoretical straight line condition, so as to achieve an acceptable bearing load distribution and shaft slope. Shaft alignment is a method or procedure by which shafts of machines such as motors and turbines are connected to a generator or pump in proper alignment. A misalignment of these three components as small as 0.
Engines, gearboxes and propeller shafts on ships are aligned. The intuitive and affordable laser shaft alignment system skf shaft alignment tool tksa 31 the tksa 31 is skf s most affordable solution for easy laser shaft alignment. Shafting alignment procedure considers static and pseudostatic loading of the. It is not intended as a comprehensive guide to alignment of process machinery, nor is it a substitute for seeking professional advice or. In addition to the consequences for cavitation at the root sections, since equation 5. An essential component of any successful alignment procedure is the. This is a very easy project and doesnt take very long to complete. Shaft alignment challenges the single sterntube bearing design. Pump alignment form fill out and sign printable pdf.
For this procedure, precalculation is used to find the gap and sag that should exist between couplings, when shaft alignment is. A new motion graphic from ludeca outlines an easy and effective way to align your rotating equipment and brings you one step closer to best. It is not intended as a comprehensive guide to alignment of process machinery, nor is it a substitute for seeking professional advice or reference to the manufacturers of the machinery. Shaft alignment handbook third edition by john piotrowski pdf. Two forms of sterntube are in use, that most commonly fitted having waterlubricated bearings with the after end open to the sea. Engine alignment must be rechecked with boat in the water, fuel tanks filled and with a normal load on board. Aug 25, 2016 when its centered, the shaft droop will have been eliminated. Running gear alignment professional boatbuilder magazine. Sep 15, 2009 as the shaft bearings are aligned, the engine is also brought into precise alignment with the shaft.
With feeler gauge find obvious gaps and fill them with shims, taking care of any rough soft foot condition. Engine must be aligned so that transmission and propeller shaft coupling centerlines are aligned and coupling faces are parallel within. If propeller is seized to the shaft and cannot be removed, have the propeller removed by an authorized dealer. Oct 28, 2010 ship shafting alignment procedure with offset of reference line. Veedrive ski boats require additional steps and instruction. For this procedure, precalculation is used to find the gap and sag that should exist between couplings, when shaft alignment is correct. The goal of precision shaft alignment is to make the rotational centerlines of the machines collinear when in operation. The way to complete the online pump alignment form on the internet. The basic procedure for determining vertical alignment of shafting and gears is to calculate, for the cold condition at time of aligning, a shape of shaft line that will produce in the hot operating condition essentially equal loads on the main gear bearings and reasonably equal loads on line bearing. When it comes to ensuring that an inboard propeller shaft and its supporting bearings are properly installed and aligned, there might be some art, but theres no magic. This strut will hold the shaft very steady, and because of this, correct engine shaft alignment is much more critical. The original function of a flexible coupling was to accommodate the small amounts of shaft misalignment remaining after the completion of a shaft alignment using a straight edge or feeler gauges.
Modelling of propulsion shaft line and basic procedure of shafting alignment calculation article pdf available in brodogradnja 593. Cardan offset shaft alignment shaft alignment training. This paper presents an approach to determine the changing displacement of the propulsion shaft due to the vessels hull deflection. Universal joint alignment procedure for passenger cars. The basic procedure for determining vertical alignment of shafting and gears is to calculate, for the cold condition at time of aligning, a shape of shaft line that will. Propeller shaft alignment forward alignment approach this alignment technique uses a laser mounted in the region of the propeller and projects a laser reference beam forward. The natural deformation of shaft sections is taken into account with rational alignment programmes and coupling conditions can be used to position shaft sections and to check alignment. When its centered, the shaft droop will have been eliminated. The ins and outs of engine and shaft alignment a laser can be used to. In most ships, the main thrust bearing is located at the forward end of the main shaft within the main reduction gear casing. This laser reference beam passes through the strut tube or cutlass bearing, the stern tube, support bearings, if any, and to the engine or reduction gearbox. A coupling should be never shaft couplings the marriage of engine to propeller shaft is the most essential link in the drivetrain. Requirement of shaft alignment every of shipyards must to meet the recommendations to prevent or minimize disturbances of the engine position, established bearing location, stern tube bearing inclination.
By aligning the engine correctly, it should last much longer along with the transmission and prop shaft. By this part of the alignment process is time to put the shaft were it is positioned, connecting the engine and gearbox, propeller installation and other elements of. While engine alignment is well understood by most marine industry professionals, shaft alignment is far more esoteric and well understood by far fewer folks in the industry. A sterntube forms the after bearing for the propeller shaft, and incorporates the watertight gland where the shaft passes through the intact hull. Youll have to pull the shaft out completely to replace them. Shaft align1 and shaft align2 are intended to enhance propeller shaft bearing performance for oil lubricated systems. Shaft alignment training course ppt presentation and machine.
If the shaft coupling isnt supported between the stuffing box and the coupling, maybe the shaft will droop down a bit because the log hose does flex, but the log on my boat is not really adjustable in respect of the alignment procedure. Figure 3 stern of vessel with the rudder and propeller fitted and. A guide to shaft alignment achieving a satisfactory shaft alignment is paramount for the safe and reliable operation of a ship during its lifetime. As the shaft and coupling are true, vibrations will be minimized. If you put the transmission in neutral and slowly rotate the prop shaft by turning the coupler around, you should see essentially little or no wiggle in the packing gland and. Here the laser has been positioned in the aftmost shaft bearing, and aimed at the transmission output coupling. The ergonomic display unit with touch screen makes the instrument very easy to use and the builtin machine library helps storing alignment reports for multiple machines. The shaft alignment procedure is not expected to start before. Shaft alignment training course ppt presentation and. Two computer shaft alignment models are used for this study. Service bulletin propeller gearbox alignment procedure description the alignment of your engine, engine mounting plate, and propeller gearbox is critical for a smooth running and long lasting gearbox. As the shaft bearings are aligned, the engine is also brought into precise alignment with the shaft. Proper alignment of rotating equipment has a long been recognized as a prerequisite to safe, reliable operation. Propeller shaft alignment is different from any other kind of conventional alignment as all shaft bearings plummer block, stern tube and bracket bearings may not.
Com is a knowledge management km consulting based maritime service provider being established among experienced and skilled professionals in the naval, maritime and offshorerelated services for more than 50years, having a vision and. This paper presents a comprehensive alignment analysis process for a long shafting system. Measure, diagnose, and correct soft foot with the assistance of the laser system and feeler gauges. Because of the rubber mounts, the engine will not be in the same position when running as it is when stopped, when the alignment is made. Shafting alignment procedure considers static and pseudostatic loading of the shafting in order to determine its static response. Lloyds register emeas technical investigations provides a comprehensive range of measurement and advisory services to help owners, operators and yards to help to ensure that the best. The truth is that it is virtually impossible to correctly align engine and shaft with the methods that are commonly used. Improper alignment leads to increase of stresses in the shafts and thus on the equipment, which might result in break down of the machine. Virtually everything we consume or use has been touched or produced in some manner by rotating gear.
Even experienced yacht people think that if you get the two faces of the propeller shaft coupling exactly parallel, the engine is aligned, but youve got a huge amount of weight, seven or eight feet of shaft and a heavy coupling, hanging out. Ship shafting alignment procedure with offset of reference line. This video is intended to guide a user through the shaft alignment process for a typical mid engine, direct drive tournament ski boat. This guide provides criteria for additional calculation requirements such as design optimization, as well as more detailed requirements regarding the shaft alignment procedures in support of the optional notations. Universal joint alignment procedure for passenger cars achieving front and rear ujoint alignment angles within the acceptable operating angle range is necessary to avoid driveline vibration and to allow the ujoints to last a long time. While engine alignment is well understood by most marine industry professionals, shaft alignment is far more esoteric and well understood by far fewer folks in. The shaft alignment class notations put additional focus on the impact of transient hydrodynamic propeller forces and moments, induced during extreme turning conditions in the upper speed range, on the aftmost. Pdf modelling of propulsion shaft line and basic procedure. A practical guide to shaft alignment plant services. In b, lining the engine up with an outoftrue shaft or coupling will result in shaft whip and noticeable vibration. If its not correctly aligned, something will have to give, and whatever that is is likely to be expensive.
Engine and propeller shaft alignment are among the most critical aspects of propulsion system installation, reliability and maintenance. Aim to have all soft foot readings within 2 mils thou. Inboard engine alignment frequently asked questions. Propeller thrust and engine torque will cause the engine to change position. The alignment of shaft with the bearing and housing, which is a manufacturing tolerance stackup of the bearing parts and the housing bores and faces. In some very large ships, however, the main shaft thrust bearing is located farther aft in a machinery space or a shaft.
Finally, remove the rods centering the shaft in the shaft long, slide the boot and packing gland back so the boot is back to where it was, and cinch down both hose clamps. The ins and outs of engine and shaft alignment part i. The ins and outs of engine and shaft alignment part i steve. Measure and correct alignment of the machine to achieve the final alignment to the required targets within tolerances. Reinove the propeller shaft froin the truck by taking out four capscrews at each end holding the flange type bearings to the fitting yokes, being careful not to let the flanged bearings fall off and perinit foreign inatter to enter the rollers. Shaft alignment tolerances historically, shaft alignment tolerances have been governed by the coupling manufacturers design specifications. Shaft alignment handbook third edition by john piotrowski pdf, lots of the substance amenities taken for granted in the modern society are made possible by the many rotating machinery systems found in each area of the planet. The acceptable offset shaft alignment tolerance for 1800 rpm is 4.
Shafting alignment is performed in several stages, starting with the shaft line design, and includes calculating the elastic line and bearing loads, installation of shafting parts onboard ship in. Achieving a satisfactory shaft alignment is paramount for the safe and reliable operation of a. The bent shaft affects alignment process by showing improper reading. The data validity rule 1 shown in following equation.
Achieving a satisfactory shaft alignment is paramount for the safe and reliable operation of a ship. Bearing load of all main engine bearings and propeller line in service condition to be within specified limits. In a, the alignment is correctable by rotating and shifting the engine, bringing the difference measured across the coupling faces to zero. Install the propeller onto the shaft with the supplied components.
Care has been taken by the authors, pruftechnik ltd, in the preparation of this publication. The alignment training is suitable for technicians undertaking machine alignment, coupling alignment, motor alignmnet, pump alignment, etc. I replaced mine last summer when i replaced my bent shaft and prop. Use this stepbystep guide to fill out the pump alignment form swiftly and with ideal precision. Jun 08, 2011 this centers the shaft in the shaft log and gets rid of the wiggle, assuming your cutless bearing was recently replaced. The full procedure is beyond the scope of this article, but in short. If the components supplied with the propeller are different than what is shown, refer to the propeller installation instructions provided with. Shaft alignment and propeller shaft aft bearing performance. Ol2r measurement of thermal growth shaft alignment with the vertizontal process. The pilot bushing is damaged, dents can be seen between the 12. Achieving proper alignment, however, involves much more than merely adjustment the machines so that the shafts are coaxial.
Engine and propeller shaft alignment are among the most critical aspects of propulsion system. The propeller shaft alignment needs to be checked once a year to check that everything is as it should be. The practices and procedures are straightforward, and if you take care to ensure accuracy and precision, the results should be predictable. Special lubricant 101 propeller shaft splines 92802865q02 flo. Design process the classic alignment technique would. Shaft alignment methods explained bright hub engineering. Produce pdf reports directly from the display unit and.
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