Protecting Bearings Using Specialty Coatings

As we’ve mentioned before, electric motors account for a majority of power usage in the US industrial sector and when they invariably fail, bearings are usually the main culprit.

Protecting the bearings on electric motors would, logically, help prolong the operation life of a motor. One solution would be using grounding brushes to prevent shaft currents or contamination from damaging the bearings. Another solution would be to use coated bearings. Writing at Design News, Daniel Juchniewicz, an applications engineer for MBP Bearings, suggests coated bearings could be the antidote for many bearing related problems.

Juchniewicz provides three areas where specialty coatings would benefit bearings:

1.Delivering wear resistance
2.Insulating against electric currents
3.Turning to wind turbine reliability

Delivering wear resistance

Bearings can be prone to wear for any number of reasons, whether due to poor lubrication conditions (associated with high temperatures and/or low lubricant viscosities), sudden variations in load or speed, standstill vibration, and/or particle or liquid contaminants. All can dramatically shorten bearing (and equipment) service Cylindrical Roller Bearing Dealers India life over time.

Insulating against electric currents

Variable frequency drives (VFDs) provide many benefits when properly installed to manage motor functions, however they also create a potential hazard: shaft currents. Currents generated by a VFD pass along the motor’s shaft and, if correctly installed, go to ground. However, if there are no other options, the current may use the bearings as its path to ground. The resulting damage to the bearings from electric arc aren’t the only hazard to the health of the bearing.

Turning to wind turbine reliability

One of the more challenging applications for bearings, Juchniewicz writes, are wind turbine systems. Varying temperatures, speeds, and loads continually test the bearings while the turbine is in service. In addition, the bearings will also have to withstand contaminants, moisture, and chemicals, which pose direct threats to the life-cycle of the bearings and effect turbine operation and maintenance costs.

Because of the multitude of conditions in which bearings operate, your mileage may vary when using specialty coated bearings. However, regardless of your bearing application, consulting with experts is a very important first step.

Read More

Explorer class bearings promise faster speeds & improved reliability

Explorer high-performance, long-life bearings range now includes an improved single-row angular contact ball bearing that delivers a number of benefits for designers and operators of screw compressors, pumps, and gearboxes seeking to reduce the total cost of ownership of this equipment through improved reliability and energy efficiency.

Featuring a redesigned brass cage that delivers reduced noise and vibration levels and improved robustness, the new 40° contact angle bearings significantly increase the limiting speed up to 30 % compared to the previous design.

The new cage geometry and the use of stronger brass material reduce cage contact forces and increase cage strength, ensuring greater tolerance of shock loads and vibration, while delivering the significantly higher speed capability even under severe operating conditions.

In addition to the redesigned 40° contact angle, a new contact angle of 25° is also offered, giving the bearing a further 20% increase in speed over that of the 40° version, while enabling higher radial loads to be accommodated. In each case, the ball-to-cage contact arrangement allows cooler running and greater temperature stability, while noise and vibration levels are reduced by 15% in both the 40° and 25° versions.

Sealed variants of these bearings are also available for applications that may be more difficult to maintain, preventing contaminants from entering the bearing during installation and subsequent operation. Bearing arrangements that include a 40° contact angle unit taking the main load with a 25° unit acting as a back-up bearing offer improved robustness for applications where the axial load is predominantly in one direction, resulting in longer service life.

Explorer class bearings are the result of years of development and accrued expertise in bearing design, tribology, metallurgy, lubrication and machining techniques. The new 40° and 25° Explorer class single row angular contact ball bearings are an attractive option for operators of screw compressors, pumps and gearboxes seeking cooler running, more energy efficient and longer life bearings that will ultimately set their products apart from the competition.

Read More

What Drives Capital Hill Cashgate Scandal Corruption In Malawi And Why It Won’t Disappear Soon

It is now two years since Malawi was rocked by its biggest government corruption scandal in history. The systematic looting of public coffers by civil servants, private contractors and politicians saw them steal US$31 million from government coffers.

It is estimated that about 35% of government funds have been stolen over the past decade. The impoverished country’s national budget for 2013-14 was about US$1.3 billion (630.5 billion Kwachas) at today’s exchange rate.

But has the country learnt anything from its biggest scandal that saw donors withdraw support?

The University of Malawi’s Blessings Chinsinga recently pointed out that:

… efforts to root out corruption do not stick because the existing institutional milieu makes it almost impossible to introduce changes that can effectively stamp out corruption.
The observation is instructive in that the scandal spans two political administrations. Malawi was led by the late president Bingu wa Mutharika in 2004 and the scandal unravelled on the watch of Bingu wa Mutharika in 2013.

Fertile ground for corruption

A number of factors contribute to the current state of affairs.

There is no clear distinction between a party in power and government activities in Malawi, unlike in established democracies. In Malawi, the party in power is the de facto government.

In Malawi, a party in power calls itself boma (a government). Ordinary Malawians look at abuse of state resources by those in power as acceptable. It is almost impossible to tell a party in power from the government.

Even more serious is the fact that political parties in Malawi are not mandated to declare their sources of funding. This breeds corruption and fosters abuse of public resources. This is not unique to Malawi. But in countries like Botswana, hailed as one of the model democracies on the continent, they at least have a debate on political party funding. Debates are also taking place in Nigeria and South Africa, respectively the continent’s largest and second-largest economies.

Another contributing factor is that after 21 years of multiparty democracy, governance in Malawi remains heavily centralised. Although the country has been independent since 1964, it only became a democracy in 1994.

Until then, it had been a one-party state decreed by its first post-colonial leader Kamuzu Banda, who banned political parties. He became president for life in 1971. Since 1994, the country has had local government representation for only six years – from 1999 to 2004 and from 2014 to now.

The central government has been reluctant to relinquish some of its powers. The president makes even the smallest of decisions and undertakes mundane tasks that should be reserved for line ministries. This encourages a system of patronage.

Lastly, government contracts, tenders and board memberships all go to sympathisers of the party in power and not necessarily to the best bidder or the most competent applicant. Government sympathisers or ruling party members get contracts regardless of their levels of competence.

This unfairly benefits the incumbents and weakens opposition parties. Businesspeople are afraid of funding opposition parties because they could lose state contracts and other business opportunities.

Scale and depth of corruption exposed

Malawians have always known that corruption is rife in the country. But the sheer size of the Cashgate scandal, both in terms of the amount and the wide number of people involved, has shown how deeply rooted the problem is.

The involvement of the country’s political class in the scandal is in stark contradiction to their penchant for standing on political campaign podiums promising to fight corruption with all their might.

Most of the people implicated in the Cashgate scandal were either members of the then-ruling People’s Party or its sympathisers.

There is an unwritten rule in Malawi that successful businesspeople align themselves with the governing party in order to protect their property and gain more contracts.

An aunt of Oswald Lutepo, thus far the main Cashgate convict and serving 11 years in jail, was heard in court lamenting that her nephew was advised that he did not need to join politics as he was already a successful businessman and multimillionaire. At the time of his arrest Lutepo was deputy director of recruitment in the People’s Party.

The aunt’s lament is instructive: people join politics in Malawi mainly to make money. In terms of this logic, the 37-year-old Lutepo was already a millionaire. He should have stayed out of it.

But he could not escape the lure of more riches that flow from being close to those in power. He knew the unwritten rule for success in Malawi only too well:

If you are unsuccessful, support the ruling party because this is where opportunities are.
Malawi is still learning to cope without support from donors and the jury is still out on whether it has learnt anything from its biggest scandal. A recent article in African Arguments underlines the hopeless feeling that Cashgate has left among most Malawians:

Malawi’s self-enriching officials need to know they will be judged not just by an imperfect judicial system, but by generation upon future generation of their compatriots.

Read More