On Site Laser Alignment
Anytime two shafts are coupled together, the importance of precision shaft alignment is paramount. There are several ways of accomplishing this goal but the fastest, most accurate method is the use of lasers.
Shaft misalignment is one the major causes of premature coupling, bearing, and seal failures in a power transmission system. Even while staying within the misalignment limits of a flexible coupling, it is still advisable and desirable to keep misalignment to as minimum as possible. There are major three advantages of Laser Alignment system rather than traditional dial-gauge alignment system is as below,
A major advantage of laser alignment tools is their accuracy. Unlike some dial indicators, there is no bar sag that needs to be measured and accounted for. Readings are also very precise.
A second major advantage of most laser shaft alignment tools is that they come with a computer system that automatically calculated what adjustments are needed and records measured values (which maintenance crews can use both to verify proper installation and watch for trends or changes in equipment movement). Dial indicators generally require hand calculations and adjustments.
A third major advantage of laser alignment tools is that they can be spread fairly far apart, which is very useful when working on two sides of a long spacer type coupling.
There are other some benefits of laser alignment over traditional methods, such as:☛ Elimination of human error.
☛ Capturing exceptionally tight tolerances.
☛ The convenience of not needing to move equipment, as the laser is portable.
☛ The ability to benchmark and track historical data.
The reasons have not always been obvious, but in the modern world the necessity of alignment is common knowledge. With today’s optimized machinery, alignment is a vital part in the daily maintenance work. Machines need to be online continuously with a minimum of interruptions. A machine breakdown causes devastating loss of production.
Nearly 50% of all machine breakdowns are caused by misalignment. Shaft alignment can be performed with different tools. The easiest way is to use a ruler or a straight edge over the two coupling halves and align by eyesight. The result is not very accurate and it is very operator dependent. A better result can be achieved by the use of mechanical dial indicators. A skilled and experienced operator can obtain good and reliable measurements, but it takes time and patience. A far easier and highly accurate way is to use laser based alignment systems. They do not require special skills and deliver accurate and reliable results.
During the alignment process two lasers are aimed at targets while the shafts are rotated by hand. Utilizing real time readings, the technician can correct for soft-foot and thermal growth conditions while obtaining the best possible readings, measured in two planes, in both angular and parallel alignment.
The benefits of precision laser shaft alignment are multifaceted on machinery:☛ Increased efficiency.
☛ Longer coupling life.
☛ Longer bearing life.
☛ Reduced heat and unwanted noise.
So if your equipment utilizes a shaft coupling or V-belts you need to have the shafts properly aligned anytime either the motor or the driven machine are moved.
Definition of Misalignment:
Misalignment is the deviation of relative shaft position from collinear axis of rotation when equipment is running at normal operating conditions.
How is misalignment recognized?
There are several symptoms indicating misalignment. By keeping your eyes open you can find them without any special equipment.
☛ Premature bearing, seal, shaft and coupling failure.
☛ Excessive radial and axial vibrations.
☛ High casing temperature at or near the bearings or high discharge oil temperature.
☛ Excessive amount of oil leakage at the bearing seals.
☛ The coupling is hot while it is running and immediately after unit shutdown. Look for rubber powder inside the coupling shroud.
☛ Loose foundation bolts.
☛ Loose or broken coupling bolts.
☛ Excessive amount of grease on the inside of coupling guard.
☛ Similar pieces of equipment are vibrating less or seem to have longer operating life.
☛ The shafts are breaking (or cracking) at or close to the inboard bearings or coupling hubs.
Misalignment effects on bearings and seals
The bearings operating life span is directly affected by the forces it is exposed to. The slightest misalignment can generate excessive forces to the bearings and seals. A misaligned machine causes stress to both bearings and shafts. As an effect of this the seals open up, allowing lubrication leakage and contamination to enter. All together the bearings lifetime is dramatically shortened.
Misalignment and power consumption
Misalignment has a direct impact on the power consumption. Documented cases have shown savings ranging from 2 to 20%. The thermogram generally shows two different couplings and the amount of heat generated due to misalignment.
Effects of base conditions and thermal variations
Even if you align your machines properly there is a risk that they break due to misalignment. If the foundation where the machine is mounted is warped you may have a soft foot condition, i.e. one of the machine feet has a poor contact with the floor. It is of major importance that this is corrected before performing the alignment. If the alignment is performed when the machines are cold, and no compensation for thermal growth is considered, the machines will probably be running severely misaligned at running temperature.
Integrating a laser alignment system into your workshop offers everything from efficient production, reduced downtime, work place safety and even ways you can save money. Take a look at the Top 5 benefits of a laser alignment system and consider how your workplace could benefit.
1. Improves Workplace Time and Cost Efficiency
With a machine running smoothly with correct laser alignment, you’re not wasting time with machine adjustments or downtime caused by breakdown and malfunction. A laser aligned machine also means you can significantly reduce the potential for big project mistakes as well as being able to rely on consistently efficient operation. This all results in smooth and productive processing which means less work time and more money saved. Also, don’t forget about the savings you’ll be making on your energy expenses by having an efficiently running machine.
2. Properly Aligned Machines are Environmentally Friendly
Something a lot of people don’t even realize is that operating inefficient and misaligned machinery also comes at a cost to the environment. There’s not only the production and consumption wastage of constantly replacing parts to consider, misalignment can also contribute to environmentally harmful fluid leaks as well as the excess energy used in running an inefficient machine
3. Reduces Downtime Due to Breakdowns and Malfunction
Operating an improperly aligned machine is asking for a world of problems – everything from vibration issues, wear and tear on parts and reduced machine performance and lifespan. All of this adds up to a lot of needless downtime while you wait around for your machines to be fixed so you can get back to work. Laser alignment ensures your machines are properly aligned, keeping vibrations in check, minimizing unnecessary wear and tear and keeping your equipment running at full capacity for longer.
4. Laser Alignment Systems Suits Measurement and Alignment Applications
Laser alignment systems have a multitude of uses on a range of machines in a variety of industries. Some measurement systems are flexible with both brackets and measurement programs, and since measurement and alignment problems often mirror one another you’ll find similarities with both your alignment and measurement needs.
5. Laser Alignment Provides a Safer Work Environment
Misalignment in some machines can cause a range of potentially hazardous problems like fluid leaks and excessive noise. By ensuring your equipment is correctly aligned using a laser alignment system, you can reduce and even completely eliminate these dangerous situations ensuring you and your team can maintain a safe and comfortable working environment.