Archive for March, 2014

Timken Steel Recycling

Friday, March 28th, 2014

Steel is basically the most recycled material on the face of the planet, even more than the sum of all the other materials combined. Its immensely high overall recycling rate is retained.

The astounding metallurgical features of steel are the main reason why it is relentlessly recycled with no compromise, performance-wise. It’s recycled and from one product to another.

Steel scrap comes from a wide array of sources. The three main classifications are: home scrap, prompt scrap, and obsolete scrap.

Timken annually transforms the equivalent of 1 million junk cars into some of the cleanest, strongest steel on the face of the planet. Watch this video.

Are Synthetics Always a Wise Choice?

Friday, March 21st, 2014

Given the amount of work needed just to convert starting ingredients into finished base oils, synthetic oils will cost you more than conventional mineral oils. Costs can run from three to five times more for common synthetics like polyalphaolefins (PAO) to several hundred times more for highly specialized fluids like fluorinated polymers.

Is the additional cost worth it, though? Well, it’s on a case by case basis. Say, for instance, being able to extend the oil drain interval with the use of a high-quality PAO synthetic-based oil by a factor of six or seven merely by opting for a product that is five times the cost of a regular one. When you factor in the additional costs linked to an oil change, then it would be money well-spent.

Aside from cost, solvency is yet another necessary factor to take into account. Being able to steer clear of some undesirable molecules is one of the perks that comes with petroleum-based synthetic oils. Aromatics are a contributing factor to a lower resistance to oxidation. But solvency is not so bad. The solution to this can be using oils that have a higher natural solvency, maybe a less highly refined mineral oil, or a nonhydrocarbon-based synthetic like certain esters, or polyalkylene glycol (PAG) fluids that come with great natural solvency.

Solvency has to do with lubricant formulation. Synthetic lubricants boast of much better shear stability as well as lessened energy consumption. However, you should be aware of what is causing excessive energy consumption to begin with. If fluid friction is not the culprit behind energy loss, even the purest and the highest quality synthetic oil will not make a significant difference, especially in applications like spur gears.

Of course, we have to consider water. Some synthetics like PAOs are clearly hydrophobic (water-resistant). But there are others that are hydrophilic (attract water). Not only do they attract water, they react with it, too. And this can bring them to their downfall. That said, compatibility with other fluids as well as sealing materials must always be taken into consideration.

So, are synthetics really the wiser choice? Take into account the physical features (viscosity, viscosity index, etc.) as well as the chemical ones (oxidation resistance, active wear protection, etc.). On top of these, think of the machine type and application, and other factors like ambient environment and accessibility for oil changes. Then you can decide once you have considered all relevant factors.

The New Design For A Turbine Bearing Seal

Friday, March 14th, 2014

An engineering firm that’s known for designing seals used in wind turbine bearings used finite-element analysis software in simulating the performance of a gasket or seal. Then they ran through a wide array of design and material potentials so as to pin down the best fit for a wind turbine’s wide operating range.

All wind turbines have at least 4 big diameter bearings, all of which to pitch every blade as well as the yaw bearing. Each requires 2 seals. These seals, at some point, might act up. And it could be for several reasons, namely load variations, temperatures, as well as small variations while being manufactured — which are, quite honestly, inevitable.

Variations in manufacturing tolerances as well as other loads could introduce deformation of a bearing. It could then alter the width of the gap between the inner and outer bearing rings. An axial offset of the two rings can lead to further issues. Furthermore, the gasket’s coefficient of friction may have a massive impact on the sealing function.

The search for solutions called for tradeoffs. Case in point: how rigid should the gasket be in order to hold its shape under load? The daily performance and maintenance needed tradeoffs, too. The gasket must not take rocket science to install and should be able to remain in place while running. Lastly, there is the unavoidable conflict between controlling cost and maximizing capability.

To come up with an answer, Schoenberg’s team utilized Abaqus finite element analysis (FEA) software, and Isight optimization software—the two being from Dassault Systèmes 3DEXPERIENCE SIMULIA application. These allowed analysts to simulate a sizable amount of variations and determine the ones that are best fitting for design goals.

The gasket’s main functions include safeguarding large bearings from environmental perils as well as seal the lubricating grease inside. Moreover, the gasket is anticipated to still be performing for 20 years even in extremely demanding environments.

The first analysis task involved making a meshed model that would run in Abaqus. The setup of its characteristics was pretty basic: Bearing metal is defined as obstinate as compared to the elastomer gasket, which had nonlinear elements.

The analysts selected 14 parameters, geometric dimensions and material properties, for optimization. And the number was cut down to six crucial parameters. They claim that through determining effects, they were able to get rid of unnecessary factors. They regularly update the design to cater to ever-changing client specs and deployment locations. Thus, it brings about a design that is not a one-size-fits-all seal.

They were able to play with design concepts which yielded excellent outcome. The gasket they were able to formulate had superior features and was less sensitive to processing and manufacturing variations, and to operating conditions for the wind turbine.

Bearing Housing Protection

Friday, March 7th, 2014

Bearings are a type of component that works on precision. Fueling them, using clean lubricants in the right amounts, will help enhance their performance and prolong their lifespan. Even the littlest contamination could stir up major issues in their reliability.

A common source of bearing housing contamination is the airborne water vapor or stream from hose-down operations. The conventional type of lip or labyrinth seals is not very efficient in keeping contamination out.

Contamination also takes place when particles get through a breather vent or from the non-pressure balanced constant level lubricators. As a matter of fact, oil contamination could arise because of the abraded oil ring material which is almost always taken for granted.

So as to prevent contamination, there should be suitable bearing housing seals. Keep in mind the exchange of external and internal air within bearings during the switching periods of operation and shutdown. That exchange could lure in contaminants.

Such breathing process within bearing housings take place because while in operation, the temperature rises, which in turn makes the gas volume expand. Then during shut down, with the drop in temperature, the gas volume contracts. Open or ill-fitted seals of the bearing housing make it easier for moisture-packed contaminated air to go back and forth.

You can help remedy this situation by shutting down every possible means of interchanging air. You should either remove or plug the breather vents well for use. A pressure compensated constant level lubricator is a much better option than the non-pressure balanced constant lubricator.

Last, but certainly not least, the most important thing to have in order to avoid every external contamination is the face seal. Using face seals for a rotating equipment, according to the manufacturer’s suggestions, can keep the bearing housings totally free of any external contamination.