NSK wheel bearing units save €58,000 in annual operating costs on a new stacker crane
High availability is one of the primary criteria for stacker cranes deployed in automated storage and retrieval systems. Downtime due to breakdowns is unacceptable as material flow becomes interrupted, which in turn means production lines or customers (in the case of finished good warehouses) are left waiting for items.Drive unit of a rail-guided stacker crane
Drive unit of a rail-guided stacker crane
A warehouse that was experiencing downtime problems requested assistance from NSK and its Added Value Programme – AIP, the proven business tool for unlocking additional profitability through improved machine reliability and increased working knowledge.
The warehouse was facing premature failures of wheel bearings on its rail-guided stacker cranes, which are a vital part of the facility´s logistics function. In total, 40 units had to be replaced within a five year period. On each of those 40 occasions, the unscheduled interruption of operations led to costly downtime and repairs.
Operating within the AIP framework, NSK experts were dispatched to assess the faulty bearings along with the environmental conditions of the application. The analysis revealed that insufficient lubrication and radial preload were the primary causes of wear on the wheel bearings.
Thanks to their ability to sustain radial and axial loads in both directions, NSK proposed the installation of lubricated, sealed for life double-row angular contact ball bearings featuring C3 class increased radial clearance. Nitrile rubber RSR seals with an integral vulcanised steel plate are a principal attribute of these innovative bearings. The seals are designed to deliver market-leading protection against the ingress of dirt and subsequently reduce wear and tear on the raceways and ball surfaces. Additional benefits include reduced vibration and lower risk of insufficient lubrication.
To demonstrate the practice behind the theory, field tests were conducted by NSK engineers. Over a one year period, the tests showed that no bearings have failed across any of the eight wheels to which they were fitted.
As a further part of the AIP process, NSK engineers amended the installation instructions and created a mounting procedure for the correct fitting of the wheel bearing units; with customer staff trained accordingly.
Sealed double-row angular ball bearing Importantly, a precise assessment of costs and benefits is included with every AIP project. For the warehouse, the calculation proved simple. Prior to implementing the NSK proposals, the prematurely failing wheel bearings on the stacker cranes were costing €70,800 per annum. This comprised OEM replacement parts (€26,880), production losses (calculated at €30,000) and repair costs (calculated at €10,000). However, with the NSK solution, annual expenses fell to €12,700. As a result, a total €58,000 is now being saved every year.
About NSK
Established almost 100 years ago, NSK (Nippon Seiko Kabushiki Kaisha) is a Japanese-listed company that has evolved from a regional ball bearing supplier to a roller bearing specialist and automotive supplier with a global market presence. Today, NSK employs more than 31,000 employees in 30 countries. As per March 2015 NSK achieved a turnover of 975 billion Yen. This result has been driven by ever-increasing investment in research & development, enabling the company to continuously improve the quality of its products and services. This investment supports NSK´s objective of »No. 1 in Total Quality». In addition to a complete rolling bearing portfolio, NSK develops and manufactures precision components and mechatronic products, as well as systems and components for the automotive industry, including wheel bearing units and electric power-steering systems.
In 1963, NSK´s first European subsidiary, Düsseldorf, Germany, was opened and in 1976, the first European production facility in Peterlee, England. Today, NSK Europe supports pan-European sales with production locations in England, Poland and Germany, logistics centres in the Netherlands, Germany and England and technology centres in Germany, England and Poland. In 1990, NSK purchased the UPI Group including the renowned European bearing manufacturer RHP, with its factory in Newark (UK). Additionally, NSK has developed a comprehensive network of authorised sales distributors. NSK Europe is divided into application-based business divisions: Industry rolling bearing technologies & linear and precision technology (EIBU) as well as bearing modules and steering systems for the automotive industry (EABU & ESBU). In this organisation, NSK Europe’s 3,500 employees achieved a turnover of over 1,000 million Euros as per March 2015.
For more information, visit www.nskeurope.com
NSK Deutschland GmbH
Harkortstrasse 15
40880 Ratingen
Nathalie SIMON
Phone: +49 2102 481 2152
Fax: +49 2102 481 2151
[email protected]