Nowadays it is widely recognised that modern relatively low cost vibration analysers are capable of detecting bearing faults in their early stages. They generally do this by measuring the high frequency bearing noise present in the vibration signal. Allowing the user to trend the bearing noise readings over time, typically via automatic upload to PC based software, enables the user to predict when a bearing will need to be changed.

In days gone by, judging the extent of bearing wearwould have been done by an experienced technician holding a screwdriver to their ear and listening to the tinkling sound of the bearing. The problem was this was highly qualitative, relying heavily on individual experience. Vibration analysershowever, allow thebearing noise to be quantified, giving repeatable measurements.Bearing noise, generally measured as vibration acceleration in units of Earth’s gravity (g), is typically presented in some more meaningful way. A typical example being Bearing Damage Units (BDU), where 100 BDU equates to 1g RMS high frequency vibration. This allows the BDU reading to be considered as an approximate “percentage” of bearing wear. In other words, a reading of 200 BDU indicates the bearing is approx. 200% worn and should be replaced!

However, that is not the end of the story. Whilst we can accurately measure high frequency vibration, in some instances not all of it is due to bearing wear. For example, pump cavitation can produce vibration that looks like bearing noise. Both are of concern of course,but how do we distinguish between them and know when the bearing needs changing? This is where temperature comes in. When a bearing starts to wear out or is in need of lubrication, it usually gets hot. This allows us to be confident that if a bearing is both noisy and hot, then it really is a bearing issue and not cavitation.

Vibration sensors with built-in temperature sensing are nothing new of course, but theseneed to be left on the bearing for a long period of time (at least several minutes) for the temperature reading to stabilise. This poses no problem for permanently installed sensors, butwould be a big issue for portable vibration analysers used as bearing checkers. With its 9085 vibration analyser, Test Products International (TPI) has overcome thislimitation by embedding a platinum resistance temperature sensor (PRT) in the sensor’s magnet mount. This allows the PRT to be in direct contact with the bearing block when the sensor is attached, capturing anearinstantaneous temperature reading while thevibration measurement is carried out.

TPI believes it has madea verysignificant contribution to affordable Condition Based Maintenance (CBM) with this low cost, easy to use, high functionalityvibration analyser/data collector. With its full colour OLED display, instantaneous temperature and vibration measurement, the TPI 9085setsanother benchmark forCBM equipment with high-speed data capture.

The 9085, with wireless battery charging,offers on-meter, easy to decipher CBM analysis for thedetection of unbalance, misalignment, looseness and bearing wear. The inclusion of instantaneous temperature capture means that worn bearings and lubrication issues can be identified beforethey become a problem. With colour-coded alarms and on screen zoom and cursors, the TPI 9085 can store up to 10,000 separate readings,all withtemperature,vibration waveform and frequency spectrum (FFT). 

The 9085includes aroute-based mode, where a list of machines can be downloaded for ease of measurementpoint identification and data collectionusingthe includedFREE, Subscription FREE, C-Trend PC software.C-Trend’s basic functions such as vibration and temperature trending and alarm reporting are totally intuitive, ensuring the software can very easilybe usedby both novice andexpert users to implement an effective CBM strategy.  

For more information, please contact TPI Europeon +44 1293 530196 orwww.tpieurope.com or email This email address is being protected from spambots. You need JavaScript enabled to view it.

This article can also be found in the issue below.

 

Rubix, the UK’s leading supplier of industrial maintenance, repair and overhaul (MRO) products and services, has released a new brochure, produced with bearings manufacturer SKF. ‘SKF Cooper Split E-Series Bearings’ is a 6-page brochure that highlights how to reduce downtime, enhance worker safety, and increase efficiency, particularly in harsh or inaccessible applications where mounting, dismantling or maintenance can be a challenge. Replacing damaged or worn bearings in heavy machinery that requires servicing or maintenance can be a problematic. Often faced with complex dismantling and assembly procedures – involving costly production losses from machinery shut down - it can take more than one person many hours to change a solid bearing. In extreme cases, it may even be necessary to break and replace a piece of expensive equipment to remove a faulty solid bearing.  These issues can be resolved with the latest range of SKF Cooper Split E-Series bearings, which can be easily and quickly replaced in situ, reducing mean time to repair (MTTR) by up to 70%. Unlike solid bearings, which must be slid onto the shaft, SKF Cooper Split E-Series bearings are split to the shaft; a design that both simplifies and expedites installation and cuts downtime when compared to replacing solid bearings of the same size.  Reducing many of the risks associated with heavy lifting, particularly at height, the latest range of SKF Cooper Split E-Series bearings also makes a significant contribution to overall worker safety. Suitable for a wide range of industrial and marine applications including belt and screw conveyors, industrial fans, industrial drive shafts, water turbines, and propeller shafts, to name but a few, SKF Cooper Split E-Series bearings feature a unique and patented brass cage design, with an optimised roller complement, which delivers increased carrying capacity, greater safety margins, longer L10 rating life, and subsequent service life. ‘SKF Cooper Split E-Series Bearings’ can be downloaded from the dedicated SKF bearings section on the Rubix website. Here, you can also not only find useful information on SKF’s Cooper Split E-Series, but also sections dedicated to specific industry specific solutions. Rubix is an SKF Authorised Distributor across Europe and has an in-depth knowledge of the manufacturer’s product range, along with early access to its latest technologies. For more information, go to uk.rubix.com  This article was also featured in the December/Jan issue below

 

NSK has developed a new type of ball screw that exhibits reduced motion errors to deliver higher surface finish quality for machine tools used in mould and die machining and other surface-critical applications. By eliminating or reducing the time needed for secondary burnishing or polishing applications, the new ball screw also contributes to higher productivity, while simultaneously reducing the amount of drive torque to save energy.

In recent years, builders of machine tools such as five-axis milling machines have been demanding increased accuracy to produce higher quality mould and die surfaces, where the ball screws used in these machines must further improve motion accuracy.

When a ball screw reverses direction, sudden fluctuations in friction cause ‘quadrant glitch’ motion errors with two peaks, leaving streak marks on the machined surface and reducing surface quality. Numerous studies conducted on quadrant glitches show that it is possible to correct the first peak through numerical control (software-based servo controller compensation). Although it is more difficult to fully compensate for the second peak due to the combined effects of more factors (compared with the first peak), NSK can now present the machining industry with a solution to this problem.

Using real digital-twin simulation and friction analysis, NSK has developed a new ball screw with an optimised internal design. Key to this outcome was the company’s understanding of the underlying mechanism of friction fluctuations in ball screws.

Among its many features, the new ball screw stabilises drive torque and reduces friction fluctuations when reversing its direction of motion, thereby improving motion accuracy and reducing quadrant glitch motion errors. The result is a near elimination of the second peak. Indeed, up to 20% less friction fluctuations also contributes to reducing the height of the first peak.

Through a combination of NSK's new ball screw and software servo controller compensation, machine tool manufacturers can assure their customers of significant improvements in machined surface quality. Furthermore, the enhanced surface quality eliminates or reduces the need for any previously required burnishing or polishing processes, reducing lead times, while lower drive torque contributes to energy savings. All of these benefits provide machine tool builders with the opportunity to pitch unique selling points to potential customers.

PR Ref. L062022-N | 1/3

1/3

 To maximise convenience for machine tool manufacturers, the mountings of NSK ball screws with quadrant glitch control are fully interchangeable with those of conventional products, allowing adoption without costly equipment changes. The ball screw will be available in shaft diameters from 25 to 63mm, with leads from 5 to 30mm. Preload types will include: offset preload (Z preload), double nut preload (D preload) and spring-type double nut preload (J preload).

 

1) Motion error during circular interpolation machining (with servo controller compensation)

 

 

 

 

2) Enlarged view of machined surface (simulated image)

 

 

www.NSK.com

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 This article also featured in the December/Jan issue below

 

 

 

 

What if we could lubricate our bearings remotely, from any device, making sure that the right amount and right lubricant are always used – and even better, based on bearing condition? Then we would address the 3 main lubrication issues which cause most of early bearing failures. Today this is already possible. Using ultrasonic sensors and single point lubrication devices, all connected to a central system, we can now bring lubrication practices to a whole new level!

Prevention in place of monitoring

We have a serious problem with bearing condition monitoring! Technology is making it easier and more cost-effective to monitor our bearings in real-time and as a result, we are seeing sensors and systems being installed on equipment at an exponential rate.  

There is a race from these monitoring systems to detect the onset of failure (Point P on the P-F curve) at the earliest possible point. And this race to detect a failure is a serious problem. We are spending more money and extra TIME to detect a failure when we should be preventing that failure in the first place.   

Addressing lubrication issues – the root of most bearing failures

It is no secret that over 80% of premature bearings failures can be traced back to lubrication related issues. These issues can be put into three general categories: inadequate lubrication (over or under lubricated), wrong lubricant, and contamination. When it comes to addressing premature bearing failure, reducing the impact on just one of these issues can have a large impact on the bearing life. But when we start to address all three, then we canreach excellence in our lubrication programs.

It’s all about the friction levels

A lot of expertise needs to be designed into the bearing selection and lubrication requirements, no technology will likely ever replace the need for trained and experienced lubrication experts.But when it boils down to it, it is all about friction - that’s why they are called anti-friction bearings.

Once the correct bearing is installed properly and the right lubricant is chosen, it comes down to managing that friction in the bearing by using the correct regreasing volume and frequency. Simple to understand but often difficult to put intopractice.

Time based lubrication vs condition-based: using ultrasound to avoid under and over-lubrication

One technique is to use time-based lubrication. In this case, regreasing is done based on time, with a predetermined amount of grease. This method is often based on an ideal calculation that is not reflective of the real-life condition that influences the friction in the bearing. This often leads to under greasing or over greasing the bearing.

A step-change in lubrication practices came with condition-based lubrication. Using ultrasound to measure the friction in real-time to determine exactly when lubrication (and how much)is required to bring the friction back to or near the ideal level. Moving to ultrasound-assisted lubrication will ensure we do not over or under lubricate but has still not addressed the two other lubrication related issues: using the correct lubricant, and contamination.

What about automatic lubricators?

To address these two other lubrication issues many have turned to automatic lubrication devices or auto lubers. Automatic lubrication provides a safer and more convenient method of supplying the precise amount of lubricant into the bearings on a more frequent basis.

These devices ensure we always use the correct grease stored in the device but also reduce or eliminate the possibility of contamination caused by the operational environment. These devices are time-based and set to dispense lubricant on a set frequency or run time.

The auto lubricant devices have evolved to become smarter. Many of them not only dispense the lubricant but can also set alarms based on excessive feedback and low lubricant.

The best of two worlds: SmartLube – single point lubricator, remotely operated, based on friction levels

We have two solutions addressing the different aspects of the common lubrication issues. On one side we have ultrasound-assisted lubrication, using friction to determine when and how much lubrication is required. Combined with good lubrication practices, it will provide benefits but still requires an investment in time and training to ensure the proper lubricant is used to reduce the potential of contamination.

On the other side, we have automatic lubrication devices ensuring the correct, contaminant-free lubricant but still based on time or running hours versus the condition or friction in the bearing, often still leading to not optimizing lubrication frequency.

What if we were able to combine the proven precision and best practice of condition-based lubrication using ultrasound with the convenience, safety, and accuracy of automatic lubrication devices? We would then have a solution that allows us to lubricate our bearings only when required by measuring friction and ensuring we always use the correct, contaminant-free lubricant every time. That’s exactly what the SmartLube from UE Systems does.

Lubricate based on friction, from any device, anywhere

When we use technology to make all this remotely operated, we can now monitor the real-time friction of our bearings and, when needed, remotely dispense the correct lubricant. All this with theconfidence that the lubricant is getting to the bearing with real-time alerts and notifications from any internet-connected device, anywhere in the world!  

The OnTrak SmartLube by UE Systems has the power of real-time bearing friction monitoring and the convenience, safety, and accuracy of single-point bearing lubricators. Lubrication experts can now lubricate remotely with confidence from anywhere, anytime, on any device.

How does it work?  

This disruptive device works with a simple concept: ultrasonic sensors are permanently mounted on the bearings to monitor friction levels. All this data is sent to a central processing unit – the OnTrak – and can be viewed in dashboards using any internet-connected device. The OnTrak then is also connected to single point lubrication devices. Based on the friction levels and on setup alarms, we now have the possibility to tell the OnTrakthat a certain bearing needs lubricant. The OnTrak will then instruct the SmartLube – single point lubricator – to dispense lubricant, just the right amount. And the best part: all can be done remotely, anywhere, anytime.

www.uesytems.com

 

 

 

 

 

SKF has unveiled a trio of new seal profiles for its SNL plummer block housings. For distributors and end-users an efficient and cost-effective means for their production has also been introduced.
 
The latest SKF seals have been developed for applications where better sealing performance is required than that provided by a labyrinth seal, but where space does not allow for a taconite seal. The new seal profiles are: TX, a single acting design with a lip seal facing outwards that prevents the ingress of contaminants while enabling grease flushing; TY, a double acting design with a lip facing outwards and a lip facing inwards; TZ, a double acting solution that features two single-lip seals in a back-to-back configuration.

Spherical roller bearings from Schaeffler now even more durable

•    Rollers with end profiling will be successively introduced in all 241-series spherical roller bearings with bore diameters of 500 mm and above.
•    Edge pressure caused by abrasive material wear is at least 20 per cent lower.
•    Their use in roller presses – which are primarily used as grinding mills for cement and raw materials but also find use in the mining industry – offers lots of potential.

Bearings are circular, much like the economy they are used in. As more customers avoid disposing of bearings needlessly, Chris Johnson, managing director of bearing re-lubricator SMB Bearings, explains the sudden surge in popularity of reusing and recycling ball bearings through relubrication.

The reliability of most rotating equipment is almost inevitably linked directly to bearing life, and it is estimated bearing failure is responsible for almost 21% of these equipment failures (Bloch, 2011).  

Research into bearing failures  shows that just over half of these are a result of contamination of the bearing oil (Fig 1). Clearly it is therefore essential to ensure that contamination of the bearing lubricant is minimised and if possible eliminated if optimum bearing life is to be achieved thereby improving the equipment reliability (MTBF).

Save your bearings with LabTecta®66, which can reduce bearing oil contamination from 83% to 0.0003%.

LabTecta®66

Research shows that 52% of bearing failures are due to contamination of the bearing oil, which represent 20.8% of all rotating equipment failures.

LabTecta®66 is a labyrinth design bearing protection seal, which is proven to increase equipment reliability in pumps, electric motors, fans, pillow blocks, steam turbines and gearboxes.

By offering a wide choice of materials and heat treatments for rolling bearings, performance and operating life can be optimised, even for the most demanding industrial applications, says Dr Steve Lacey, Engineering Manager at Schaeffler UK.

In recent years, there has been a significant increase in the demand for rolling bearings that, even under extreme operating conditions – including lubricant starvation, highly corrosive or high temperature environments – still provide a long operating life and optimum performance.

But selecting a suitable material or heat treatment process for rolling bearings often requires expert advice and guidance, normally from the manufacturer of the bearings. Selection depends on the application itself and the specific environment in which the bearings will operate. This means a number of factors require careful consideration, such as the mechanical, chemical and thermal requirements placed on the bearings, as well as lubrication conditions, particularly if the application requires dry running bearings.