This is a wideranging process, not only focusing on the direction in which the shafts are pointing, but also stipulating demands in relation to factors throughout the. The suggested tolerances shown on the following pages are general values based upon over 20 years of shaft alignment experience at. Aug 02, 2016 the first principle to grasp is the fit designation of the shaft hole joint. If the shaft will extend into the spider, check table6 to ensure the shaft will fit in the open center in the spider. A coupling alignment tolerance and a shaft alignment tolerance are different things very different things. The fit designation ranges from clearance fits to interference fits. 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. Abstract shaft alignment is a key factor in reducing vibrations and. Spacer shafts and membrane disk couplings offset per 100 millimeters the suggested tolerances shown below are general values based upon over fifteen years of shaft alignment experience at pruftechnik ltd and should not be exceeded. For equipment with long distances between the shaft ends, it is possible to fit the coupling and check the alignment of one shaft to the spacer and then check the spacers alignment with the second shaft. Produce pdf reports directly from the display unit and save to usb. Shaft alignment laser measuring resolution down to 0. Moreover, as the name suggests, the main purpose of shaft alignment is to make sure that the center line of the motor rotor shaft coincides with the center line of the driven machinery i.
All dimensions in inches motor frame shaft length typical v shaft diameter tolerance u t. It should be recognized that shaft runout and coupling surface runout do not affect shaft centerline alignment when both shafts are turned when making alignment measurements. Section 1 shaft alignment page number what is shaft alignment 9 a definition 9 machine catenary 10 operation above critical speed 11 expressing alignment alignment parameters angularity, gap and offset 14 short flexible couplings 17 spacer shafts 18 how precise should alignment be. Shaft alignment training course ppt presentation and. The hubs could be moved back on the shafts or overhung slightly to. The primary reasons why machinery is misaligned is lack of proper training, improper tools to do the job, and that people are not given enough time to do it right. This standard is the application of alignment concepts concerning relative positions of rotating shafts connected by mechanical means. Dec 01, 2002 shaft alignment tolerances historically, shaft alignment tolerances have been governed by the coupling manufacturers design specifications. Improper alignment leads to increase of stresses in the shafts and thus on the equipment, which might. An engineers guide to shaft alignment, vibration analysis. The eight powerpoint presentation modules in the shaft alignment course are. Pdf basic shaft alignment workbook for industrial rotatin.
Machinery alignment tolerance tables the suggested alignment tolerances shown here are general values based upon experience and general industry standards and should not be exceeded. Achieving proper alignment, however, involves much more than merely adjustment the machines so that the shafts are coaxial. It will also explain why it is absolutely necessary to have both the short flex and spacer shaft tolerance options when performing an alignment. Rotalign touch is the first laser alignment tool fully designed to meet the requirements of industrial iot with rfid, wifi, and cloud data transfer. Yes, the shaft coupling to transmission coupling needs to fit within several thousandths, but what were talking here is the coupling fit, not the shaft alignment. Rotalign touch advanced laser shaft alignment system. While it is safe to say the coupling will not fail if aligned to their tolerances, it is not safe to say that bearing, seal, shaft. When you opt to use your own shaft alignment tolerances instead of using the industry standards, how do you decide what to use.
The acceptable offset shaft alignment tolerance for 1800 rpm is 4. The nature of inboard drive systems it is a common belief that engines and shaft couplings have to be aligned to tolerances of a few thousandths. Proper alignment of rotating equipment has a long been recognized as a prerequisite to safe, reliable operation. Facilities instructions, standards, and techniques volume 21. 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. Alignment of the shaft is necessary when the motor or driven machinery is new or when it is dismantled due to improper running. Standard industry norms for alignment tolerances are cited in table 1.
Measurement can be taken at any 3 or 4 positions and the sensor angular position is automatically considered. Shaft alignment store shaft alignment by vibralign. Criteria for alignment tolerance the first alignment tolerances were dictated by the coupling manufacturer, by how much misalignment his coupling could take before it locked up. Before installing the drive however, always verify that the motor meets the standard shaft diameter and t. The flats support the shims andor feet of the machine to be installed. A practical guide to shaft alignment plant services. Reference tables lawrence berkeley national laboratory. Proper shaft alignment is especially critical when the motor is operated at high speeds. Shaft alignment tolerances the coupling manufacturer is generally concerned with their product effectively transmitting energy from one shaft to another. Article on shaft to shaft alignment by fourdial gage method for coal handling plant new approach by. A survey conducted by one of the worlds leading rotating equipment service organizations. The goal of precision shaft alignment is to make the rotational centerlines of the machines collinear when in operation. Shaft centerline alignment is the positioning of the rotational centers of two or more shafts such that they are colinear when the machines operate under normal conditions.
If a manufacturer of a machine or coupling require tighter alignment tolerances, those should be used. He is a member of asme, the vibration institute, and the pacific energy association. For this method it is necessary to record all four cardinal readings. 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. Laser shaft alignment pump laser alignment easy laser. Here you can download the pdf template of the tksa 20 shaft alignment report, which can be used for documenting of your alignment activities. Shaft alignment training course ppt presentation and machine. With feeler gauge find obvious gaps and fill them with shims, taking care of any rough soft foot condition. Aim to have all soft foot readings within 2 mils thou. Acceptable alignment tolerances are thus a function of shaft speed and coupling geometry. Coal handling plant alignment standards for shaft to shaft. Jun 15, 2012 the shaft alignment store accepts orders and ships to usa based customers only. Shaft alignment tolerances historically, shaft alignment tolerances have been governed by the coupling manufacturers design specifications. The subject of shaft alignment tolerances has been touched on before but a couple interesting discussions have taken place recently during training classes.
Sep 17, 2009 welcome to part 1 of 3 in a series discussing rotating machinery alignment tolerances. Builtin ansiasa shaft alignment tolerances alignment data can be stored in the xt application, usb drive or emailed directly as a pdf report including measurement data, color images and signature. Shaft alignment is the process of aligning two or more shafts with each other to within a tolerated margin. The fixturlaser xas and gos allow you the option to. The alignment standard suggested for fourdial gage method, which provides the technician the recommended approach for the quickest way with quality alignment.
This is shown in figure 7 as the tilting movement of the gear tooth. When the centerlines of their rotating shafts dont match up perfectly, it can lead to wasted power, accelerated component wear, and even the equipment failures the following are the most prevalent causes. The bent shaft affects alignment process by showing improper reading. The book is reference material on rotating machinery basics, pump overhaul, mechanical seals, basic vibration, and shaft alignment. Jul 03, 2018 at ansi american national standards institute in the usa, work has been conducted for some time aimed at standardizing shaft alignment tolerances for axially coupled machines. Examining the 1800 rpm shaft alignment tolerances in the above table and comparing to the tolerances for the 3 coupling sizes above. Machinery alignment tolerance tables impact engineering. For example, the only correct way to express shaft alignment tolerances is in terms of alignment conditions at the coupling, and we will describe several ways to do this. The ludeca rotalign ultra is wellsuited for laser alignment of cardan shaft applications. The shaft alignment store accepts orders and ships to usa based customers only.
Shaft tolerance h11 h9 h7 h6 h11 h9 h7 h6 h11 h9 h7 h6 h11 h9 h7 h6 h11 h9 h11 h9 h7 h6 h11 h9 h7 h11 h9 h7 h6 iso 1829 ansi b4. They should be used only if no other tolerances are prescribed by existing inhouse standards. The 1day shaft alignment training presentation covers the entire process of machine alignment from pre alignment checks through to providing shaft alignment tolerances. Reverse alignmentunderstanding centerline measurement by c. 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. Australia germany italy preferred tolerances in metric preferred. If a manufacturer of a machine or coupling requires tighter alignment tolerances, those should be used. There are two types of misalignment, offset and angular see figure 2.
This is an intuitive concept to grasp a clearance fit specifies a fit where there will always be a gap in the joint between the mating shaft and hole. At ansi american national standards institute in the usa, work has been conducted for some time aimed at standardizing shaft alignment tolerances for axially coupled machines. Flexible couplers can tolerate small alignment errors, but for smooth, troublefree running, it is important to ensure that these two shafts are lined up to within the tolerances specified by. 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. They are to be used only if no other values are prescribed by existing inhouse standards or the machine manufacturer. It should be noted that todays highquality flexible couplings are. Propeller thrust and engine torque will cause the engine to change position. The purpose of this document is to provide guidance for vertical shaft alignment including when alignment procedures should be. As used in this specifications, a flat is a small surface flush with or cut into a base plate, machined flat, and coplanar with the other flats in the base plate. The truth is that it is virtually impossible to correctly align engine and shaft with the methods that are commonly used. It is incorrect to describe them in terms of correction values at the machine feet, and we will examine why. You must first take the wobble out of it, then align the coupling flange on. Article that describes a new way to perform laser shaft alignments by performing both the vertical and horizontal adjustments from one set of alignment data, what vibralign now calls the vertizontal compound move.
The suggested tolerances shown below are general values based upon over fifteen years of shaft alignment experience at pruftechnik ltd and should not be exceeded. Alignment tolerances no industry standard on alignment exists. When shafts are aligned, the offset and the angular must be aligned. The coupling manufacturer is generally concerned with their product effectively transmitting energy from one shaft to another. While it is safe to say the coupling will not fail if aligned to their tolerances, it is not safe to say that bearing, seal, shaft, and other equipment component life will not.
A coupling alignment tolerance is often but not always the maximum amount of misalignment the coupling will operate at before premature failure. Regarding john gross question about how a shaft can be aligned with so many things being so wobbly. Pulley alignment guide precision alignment is an essential part of a proactive reliability program. Compressor engineering corporation in the optical alignment field, until the formation in i985 of bently nevada alignment service corporation.
Are you aligning to the new ansiasa shaft alignment. This system features optional wireless communication, as well as a cardan shaft alignment mode that allows the user to focus only on the angularity that exists between the driver and driven shafts. Dual psd, dual laser beams and dual inclinometers for superior control and accuracy. That is 25 times better than the elastomeric insert coupling tolerance and 1. Hole alignment tolerance stacking issues fritz scholz mathematics and computing technology boeing phantom works february 24, 1999 abstract each of two parts has k coordination holes with the intent that each hole on one part is paired and to be pinned with a corresponding hole on the other part.
Link to an article discussing how to choose which tolerances to align to. How shaft alignment tolerances must be expressed the only correct way to express shaft alignment tolerances is in terms of alignment conditions at the coupling, and we will describe several ways to do this. It contains specific tolerances, factors affecting alignment, and an overview of various measurement methods, following the core technical components of measure, analyze, correct, and document. This presentation breaks down and simplifies the definitions of short flex and spacer shaft tolerances. Listed below are descriptions of some of the components most closely associated with the unit alignment. This guide provides information for the implementation of good pulley alignment of beltdriven equipment including terminology, alignment methods as well as belt maintenance, storage and tensioning.
In addition to providing guidance on shaft alignment tolerances, the standard describes methodology applicable to manual and laser measurements. Other alignment methods include shaft tocoupling spacer, optical systems and electronic indicators. Ideally these two shafts will be exactly parallel and have exactly the same centreline. Track machine movement over time with easytrend optional dmbrackets required. Total indicator reading shaft runout tolerance 182t184t 2. The efficiency of laser shaft alignment active clock measurement mode intelligent and precise alignment due to the activated mems inclinometer used in this measurement mode. If, on the other hand, you update your knowledge of shaft alignment techniques and acceptable alignment tolerances, you might be on the way to becoming more reliabilityfocused.
In practice, proper alignment is difficult to achieve without using alignment equipment such as dial indicators or laser. The suggested alignment tolerances shown here are general values based upon experience and general industry standards and should not be exceeded. Before installing the drive however, always verify that the motor meets the standard shaft. The following suggested alignment tolerances are the desired values. In practice, proper alignment is difficult to achieve without using alignment equipment.
Shaft alignment methods explained bright hub engineering. All types of machines having shafts as an integral part of their structure, experience problems related to shaft alignment. A pad is a small block of metal that serves to elevate the feet of the machine above the surface of the base plat e. Basic shaft alignment workbook for industrial rotatin n1achincrv. 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. Assembly within recommended tolerances will equalize loading and cyclic. These standards are useful only for shafttoshaft alignment of thermal power stations coal handling plants. If a manufacturer of a machine or coupling require tighter alignment tolerances, those should be used consider all values listed to be the maximum allowable deviation from the alignment target. Shaft alignment tolerances spacer couplings6, 7 angularity angles a and b, or projected offset offset a, offset b excellent acceptable rpm milsin mmmm milsin mmmm 600 1. Arc graph was compiled from a large they within acceptable alignment number of case histories where tolerances. Hello members i would like to have clarification with regards to shaft alignment tolerances mentioned in api 686 second edition dec 2009 clause 5. Research paper on specifying shaft alignment by victor wowk, p. Terminations shaft diameter up to 28 mm are made with tolerance j6, shaft diameters from 28 to 50 with the k6 and higher shafts diameters are made with m6.
Facilities instructions, standards, and techniques volume. Electronic and electrooptical shaft alignment systems. If a manufacturer of a machine or coupling requires tighter alignment tolerances, those should be used consider all values listed to be the maximum allowable deviation from the alignment. The first principle to grasp is the fit designation of the shaft hole joint. Shaft alignment tolerances are used to ensure that a machine is properly aligned for the rpm it runs at. Use dial indicators or laser systems to check the alignment of directlycoupled shafts.
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