Sweden-based Derome Timber experiences sixfold increase in bearing service life
By using Timken® spherical roller bearing solid-block housed units, the Swedish company Derome Timber AB increased cost efficiency and productivity in one of its sawmills on a long-term basis. The Timken assemblies achieved a service life in this application that was more than six times longer than that of a competitor’s product.
In a Derome Timber sawmill in Sweden, Timken spherical roller bearings with a solid housing achieved a service life more than six times longer than a previously used competitor’s bearing equipped with a cast-iron housing.
Derome experienced challenges keeping the chain conveyor up and running at a sawmill in Veddige, on the west coast of Sweden. The conveyor system is part of equipment that rotates the logs for further processing. The heavy logs fall from a height of 50 cm onto the conveyor belt, causing severe shock loads upon impact. The climatic conditions (the machines are outdoors) combined with significant contamination create challenging conditions for the bearings. A competitor’s cast-iron bearing housings withstood these loads for three to four months. By then the housings were damaged or broken and dirt had penetrated into the interior, necessitating replacement of the bearings.
Nomo Kullager AB, a preferred Swedish distributor of Timken products, recommended Timken spherical roller bearings with solid housings because they stand up to harsh conditions. The housing withstands blows and falls, and the bearings accommodate misalignments of up to ±1.5 degrees. Additionally, the ends of the feet on the housings are machined, which allows the keeper plates to fit tightly to the housing for one-time shaft alignment.
The Timken housed units have now operated for more than two years in the Derome sawmill. “They have performed flawlessly and continue to look very good,” said Viktor Mattsson, a sales representative at Nomo in Gothenburg. Dan Bertilsson, sawmill maintenance manager, noted the significant savings. “For us, more than six times the service life means a considerable advantage. In this way we are able to reduce the repair and replacement time to a minimum and concentrate on other important things,” he said. The company is gradually substituting the Timken assemblies for the units previously in use.
Timken spherical roller bearings with a solid block housing were developed for the harshest working conditions. They are capable of withstanding blows and falls and are available with optional steel covers (picture below) to protect against heavy soiling.
These housed units are designed for 40 to 180 mm shafts and are available in various types of housings, depending on the requirements. Users choose between labyrinth seals (Dupont Teflon®) and triple lip seals (nitrile or urethane). Milled pedestals, threaded puller bores, black oxide inner rings and numerous locking options for the shafts make it simple to install these high-performance units. In addition, optional steel covers protect the roller bearings from the heavy soiling that is typical in many industries, forestry among them.
About Derome Timber AB
Derome Timber, a Derome Group company, is one of the leading wood processing companies in Sweden. Derome sawmills produce and finish about 400,000 m³ of timber, not only for Sweden but also for export markets in Europe and North Africa. In 2013, the Group’s 1,000 employees achieved sales of about SEK 3.4 billion.
About The Timken Company
The Timken Company (NYSE: TKR; www.timken.com) engineers, manufactures and markets Timken® bearings, transmissions, gearboxes, chain, and related products, and offers a spectrum of power system rebuild and repair services around the world. The leading authority on tapered roller bearings, Timken today applies its deep knowledge of metallurgy, tribology and power transmission across the broad spectrum of bearings and related systems to improve the reliability and efficiency of machinery and equipment all around the world. Known for its quality products and collaborative technical sales model, Timken posted $3 billion in sales in 2013 (excluding Steel business sales). With approximately 17,000 people operating from 28 countries, Timken makes the world more productive and keeps industry in motion.
Photos : Nomo Kullager & Timken