DOES THE Z AXIS AFFECT ALIGNMENT?
In short, no it does not. There are aspects of the z axis that could affect the running of a machine, but rotational shaft alignment is not of them.
What is the Z axis?
The X and Y axes are references to horizontal and vertical planes respectively. With regard to precision shaft alignment, this refers to the vertical and horizontal correction(s) necessary to adjust the position of two or more shafts when aligning them to be collinear. The Z axis is the axial plane. This is the movement of the shafts along the rotational axis of the shafts typically referred to as thrust. Thrust does not necessarily affect the machines alignment position.
Why should you be concerned about thrust when aligning a machine?
The primary concern regarding thrust is to allow the proper clearances between shaft ends or coupling hubs. Clearances are required to allow axial movement caused by any force acting upon the machines. Examples are: Thermal growth, bearing play, gear lash or magnetic centering. If the gap is too small, shaft ends or coupling hub faces may come into contact with each other causing damage to the machine components. If no damage occurs, the least would be increased vibration in the machine.
Blog by Tom Shelton, Vibralign
TECHNOLOGY – FOR IT OR AGAINST IT?
In today’s industrial world, prolonging the efficiency of rotating equipment along with reducing the amount of unexpected shutdowns, has become more important than ever. In order to do this, supervisors and maintenance directors want to see the difficulties arising before they have an effect on their process. Till now, vibration teams or third party vibration companies have been the best way of detecting issues before they arise. The mindset has always been to monitor and do route based analysis on critical applications which typically results in approximately 20% of applications being cared for. The remaining 80% are typically not monitored or on a vibration route, however, in some cases, are checked either via ultrasound, thermography cameras or on a lubrication check process.
The future of preventive maintenance is in the ability to have anyone check the health of their equipment whether it be sporadically or route based. A well developed, reliable, easy to use and efficient auto diagnostic system allows for mechanics or preventive teams run checks on their equipment with no vibration knowledge. This will allow for vibrations teams to dedicate 100% of their time to analyzing the critical applications along with troubleshooting the more complex issues while knowing that the rest of the equipment I being checked. Some analysts have gone as far as using a “check and confirm” approach, meaning they use a auto diagnostic tool on all of the machinery on their route, and confirm the findings versus the “analyze to find” approach, in which they analyze every spectrum to determine the cause of the vibration. In other words, any auto diagnostic result that does not show a default, is considered ok and any result that shows a default, is analyzed and confirmed. This has allowed analysts to save a tremendous amount of time and in some cases even allowed them to add machines to their routes. Although technology will never replace human expertise and experience, if those responsible for maintenance can embrace what it has to offer by changing their mindset, it will without a doubt strengthen the preventive maintenance goals of many companies.