Authorised diagnosis and repair facility
for aerospace-approved bearings, provides
fast turn around times for customers

The Barden Corporation (UK) Limited's manufacturing plant in Plymouth is now an authorised diagnosis and repair facility for aerospace-approved bearings, providing fast turn around times for customers.

The Civil Aviation Authority (CAA) has now approved The Barden Corporation's manufacturing plant in Plymouth as an authorised diagnosis and repair facility for aerospace-approved bearings.

The plant's new EASA (European Aviation Safety Agency) Part-145 approval means that Barden can offer customers rapid turn around times for aerospace-approved bearings, including Level 1 inspection and Level 2 refurbishment.

Brian Williams, Director of Quality, Aerospace Division, Barden Corporation (UK) Limited, comments: "We're not talking about standard, catalogue industrial bearings here. These are super precision aerospace-approved bearings, where full traceability is critical. The bearings typically carry a form of passport around with them at all times and are subject to very strict, highly regulated aircraft maintenance programmes. The EASA Part-145 approval enables us to service the commercial aerospace markets in Europe, where there is now a demand for fast turnaround times on key aircraft components. This includes bearings for small engines, gearboxes and auxiliary power units."

If aircraft OEMs have no replacement bearings in stock, they can now send used bearings to Barden's new Diagnosis & Repair (D&R) facility in Plymouth. As Williams explains: "Initially, we would strip down the bearing and examine it for signs of wear. If the bearing is within acceptable limits, it is then cleaned and reassembled prior to being packed and returned to the customer as a 'serviceable' item. This is Level 1 - diagnosis. Bearings that fall outside acceptable limits may, in some cases, be refurbished in accordance with defined repair schemes. These are Level 2 - repair activities and may again result in 'serviceable' product. Bearings that are beyond economic recovery are tagged as 'unserviceable' and returned to the customer."

He cites a typical refurbishment example: "Some of the bearings have a silver-plated cage. The coating is sacrificial and so can eventually wear through. Provided that the wear is within acceptable limits, we can strip and re-apply the silver coating; thus avoiding additional delays associated with re-manufacture. Other examples of refurbishment include the re-polishing of the bearing raceways and replacing the rolling elements."

"If the bearings are recoverable, we can refurbish them in rapid time, normally within seven days. This is significantly faster than the customer having to wait for a replacement bearing, which can take anything from 12 to 24 months."

"For the customer, the inspection and refurbishment of the bearings is not really about cost. Lead time is far more important, especially when you consider the cost of keeping an aircraft on the ground rather than in the sky."

"Maintenance programmes for aircraft engine components and APUs are becoming increasingly important, as airlines try to maximise the life of their existing equipment. In general, aircraft are getting larger in size and are flying for longer periods, which means maintenance is more frequent. Therefore, rapid turnaround times for diagnosis and repair of aerospace-approved bearings is becoming even more critical," he adds.

Gaining the EASA Part-145 approval has required more than 12 months of hard work that involved planning a new dedicated D&R station at Plymouth and visits from CAA auditors. The Plymouth plant now has a self-contained, access-controlled, 1,800 square feet D&R station, with storage racks, working surfaces and inspection equipment. At present, the station can handle bearings up to 300mm outside diameter. Phase Two of the project will see the D&R station expanded to include dedicated receiving, cleaning and measuring equipment.

The service is not only applicable to aerospace-approved bearings, says Williams. "Any industry in which regulatory approvals are high or where traceability of the bearings is required, we can help. This might include bearings for rail applications or nuclear installations."

"In addition, the services are not just applicable to bearings manufactured by Barden - as long as the customer has approved technical data and a repair scheme for us to work to, then we can provide the Diagnosis and Repair service."

A market leader in the design and manufacture of super precision ball bearings for more than 60 years, Barden has supplied products to a range of extreme environment applications, including vacuum pumps and the aerospace industry. With a customer base that includes NASA, BAE Systems and a number of other leading aerospace and defence companies, Barden boasts state-of-the-art production technology and a wealth of engineering expertise.

A high percentage of Barden bearings are tailor-made for specific applications. The product range encompasses predominantly radial, single row, super precision, angular contact and deep groove ball bearings which meet and exceed ABEC 7/9 standards. Bearings are manufactured and controlled under strict aerospace procedures, providing full traceability, controlled lubrication and complete retention of records. Manufactured bearing sizes range from 5mm to 250mm outside diameter. The company is capable of manufacturing bearings to a geometric tolerance of P2 or better, and envelope dimensions to P4 or better. Raceway roundness is better than 0.5µm, with raceway surface finish better than 0.025µm Ra.

Barden Corporation (UK) Ltd in profile
Barden Corporation (UK) Ltd a recognised world leader in super-precision bearing systems. For more than 60 years, Barden has built on its unrivalled manufacturing expertise and its ability to design bespoke engineering solutions for a variety of difficult applications. The company offers an extensive range of super-precision bearings for a variety of applications, including aerospace, turbomolecular pumps, medical instruments, machine tool and motorsport. Now part of the Schaeffler Group, Barden UK holds an enviable position alongside sister manufacturing plants around the world. For further information, e-mail: caroline.evans@schaeffler.com or view website: www.bardenbearings.co.uk    Refer to page 73

Cropico microhmmeter digs deep
at quarry electrical safety testing house

A high performance Cropico microhmmeter is being used by certification, testing and inspection house Bureau Veritas to test the safety of cables installed in quarries operated by contractors across Britain.

Bureau Veritas has extensive UK coverage, providing safety testing and risk assessment services for national and international manufacturing and industrial clients. The company has been used by organisations since 1828 to ensure compliance with health and safety regulations and to manage risk factors on work sites.

Electrical circuits installed within quarries, must be tested in order to ensure no damage during installation and in service. A low resistance microhmmeter, with a 10A test current, is essential for testing such as this, due to the low resistance of the cables, which cannot be accurately tested using a regular ohmmeter.

Bureau Veritas has specified the DO7010 to inspect the safety of these circuits because if left unchecked, they can continue to function but offer a high risk of fire or electric shock - extremely dangerous to those working on site.

Mahendra Mistry, electrical engineering specialist at Bureau Veritas, said: "The accuracy of the DO7010 was a key factor in my decision to use it for testing the quarry installations.

It's also an extremely reliable instrument while being portable and easy to use.  It meets all of our requirements."

The DO7010 has been developed for a wide range of electronic engineering, design and manufacturing applications requiring accurate low resistance measurement.
With a measuring range of 600µΩ to 60Ω with 0.1 and 10mΩ resolution respectively, the instrument can measure with switchable current levels of 1A or 10A on all except the highest range. Externally recharged NiMh battery packs can be replaced quickly via the front panel to ensure minimum downtime anywhere.

An LCD panel displays full information on measurement configuration and a single start button ensures ease of use while the ability to trigger measurements by lead contact to the test device provides fast single-person operation. A remote hand terminal is also available to fully control the tester at up to 15m distance.

Other features include a robust design, true 4-terminal measurement to eliminate lead resistance errors, auto average of forward/reverse measurement and sequence testing with memory for 1000 readings.

The instrument's data logging function also permits downloading of test sequences from a spreadsheet and uploading of test results back to the data records. The DO7010 forms part of a comprehensive range of precision measurement instruments available from Cropico, part of the Seaward Group.

For further information, view website: www.cropico.com   Refer to page 260