60 months between gear oil changes? Yes, says recent filter

Oil quality is a decisive factor for the service life of a gearbox. In addition to the type of lubricants used, (e.g. synthetic oil with improved lubricating properties to extend service life) a recent upgrade increases potential to optimize oil quality and extend service life.

Gearbox wear is determined by operating conditions and stresses exerted on components. Hence, gear-oil life is difficult to estimate. Impurities, the degradation of additives, and oil-aging products generated during operation all contribute to premature aging of gear oil.

Most gearbox manufacturers recommend no more than 36 months between oil changes. In some cases, the service life of gear oil is not met due to impurities that cause the main-flow filter to prematurely fail. Research shows that only a small percent of the main-flow filter’s dirt-holding capacity absorbs impurities. This was sometimes due to a deposit of oil-aging products that formed a seal over the main flow filter, causing its failure.

Availon engineers, however, found that a recent kidney-loop filtration upgrade improves oil quality and prevents the need to perform some filter and oil changes recommended by the manufacturer. This reduces downtimes and some costly repairs.

The upgrade was developed for systems with a fine filtration level of 10µ or greater.

As the development’s name implies, kidney-loop filtration provides an oil flow to clean the gear oil independent of the main flow filter. Oil-aging products and particles larger than 3µ are removed from the lubricant. The filter also removes moisture from the oil. Contrary to common thinking, finer filtration does not remove additives. They remain in the gear oil. The upgrade consists of a compact pump and filter unit, installed near the gear coupling or on the gearbox. The unit siphons oil from the lowest point of the gearbox through a hose, cleans oil inside the unit, and returns it to the gearbox.

Availon engineers say installing a kidney-loop filter only takes about four hours. The amount of time between filter exchanges depends on the degree of gearbox-oil contamination. However, the oil’s required purity class, according to DIN ISO 4406, differs between gearbox manufacturers. Evaluation of oil analyses based on samples taken at regular maintenance intervals shows that, during regular operation, a standard gearbox has an oil-purity class of 22/20/17, which is usually a higher degree of soiling than specified by the manufacturer. The oil filter should be replaced six months after installation and then at 12-month intervals. The filter can be replaced during normal maintenance work, depending on its wear.

The kidney-loop filtration unit can extend intervals between gear-oil exchanges to 60 months or more, saving the cost of frequent oil changes. Also, filter changes between regular maintenance intervals are no longer required after installing the upgrade, says Availon. Minimizing costs, maximizing efficiency, and extending the life of such components is crucial in low-wind years. A few turbine manufacturers already include kidney-loop filtration in new models and say the oil change interval depends on the result of an oil analysis.

Availon

www.availon.eu

Powder composites make low-loss chokes and filters

A line of inductive components feature low-loss, good EMC characteristics, and a space-saving design. Their cores consist of powder composites, which developer SMP (Sintermetalle Prometheus GmbH & Co.) engineers for each application. And depending on application, components are constructed either as single-conductor chokes for high-current applications, individual chokes, choke modules, or LC filters. The devices work in inverters for wind turbines and photovoltaic plants and other drives and power electronics. SMP manufactures all components to application requirements using in-house-developed powder composites which offer high energy storage capacity.

SMP’s inductive components handle frequencies to 200 kHz and currents to 1,000A. All products are RoHS and Reach-compliant and materials used are UL-listed. For a wide range of requirements, components can be made to all common international standards. The company will display at the trade fair for components, systems and applications; November 9 to 12, 2010, Neue Messe Munich, Germany: Hall B3, Stand 153

For SMP, Westendorf Assoc.
westendorfassoc.com

Filters for wind-turbine hydraulics

Eaton’s Vickers Filters handle flows to 450 gpm and pressures to 6,090 psi. Bypass valves, pressure drop indicators, and media grades facilitate filter installation and provide needed system cleanliness. A closer look at reservoir vent filters shows its useful features.

These sport visual indicators and corrosion-resistant housings. In addition to particle control, these filters also feature water and moisture control needed in harsh wind-turbine environs.

The Dirt-Gate Reservoir Breather, in particular, filters out airborne particles before they contaminate the oil. Hydraulic reservoirs “breathe” air in and out as the oil level rises and falls. This air contains water and particles that are destructive to machinery over long periods. The H₂0-Gate Reservoir Breather filters out particles and moisture before they contaminate oil.

During an oil tank’s “inhalation” cycle, the H₂O-Gate proprietary media blocks water vapor from entering the reservoir. During “exhalation”, the media lets moisture in the reservoir air exit. Moisture is carried off the media by the exiting air, restoring the media’s water barrier capacity. Eaton says the moisture barrier mechanism is unaffected by the amount of moisture exposure.

The company adds that it is committed to contamination control and superior performance of its products. To prove it, the company will extend the standard warranty by three years of all Vickers products used in a system protected by Vickers filters when they are applied consistently to principles of the company’s PAM program.