PRODUCTS BEARINGS, SEALS & GASKETS BEARINGS: REPLACE OR REMANUFACTURE?


There is increasing demand for remanufactured bearings in heavy duty industrial applications – after all, it takes around 100 process steps to produce a new bearing, compared to roughly ten for a remanufactured bearing. Remanufacturing


involves rebuilding a bearing to either meet or exceed the specifications of the original manufactured product. Bearings


with more than 30% of their remaining service life can be remanufactured and this can offer a practical and environmentally sustainable solution. The key is knowing when to opt for remanufacturing and which approach will yield more cost-savings in the long run. Firstly, the used bearing must undergo a thorough inspection during which it will be disassembled, cleaned and


degreased. Following a visual inspection, microscopic inspection, dimensional inspection and testing will occur. An analysis report will detail recommendations for appropriate refurbishment and remanufacturing processes. Reclassification services then follow – encompassing minor repair, demagnetisation, dynamic testing,


relubrication, reassembly and packaging for the bearing’s return to industry. If, however, further intervention is needed, refurbishment is called upon. This will include the previous actions in addition to one or more of the following: replacing rolling elements, remanufacturing the bearing’s cage, replacing components like seals and snap rings, grinding or polishing and plating mounting surfaces, and polishing raceways. Remanufacturing is the final set of services – including grinding, installing a new ring and modifying the


component. At this stage, engineers can opt to improve the performance or properties of the original bearing to increase operational efficiency and decrease future maintenance interventions. Upgrade possibilities include adding features such as black oxidation or incorporating additional sensor functions for condition monitoring. Large bearings such as spherical roller bearings, deep groove ball bearings, tapered roller bearings,


caster bearings and slewing bearings are good candidates for remanufacturing. As an example, if a large industrial bearing in a pumping system failed unexpectedly before the end of its service life, remanufacturing could increase the life cycle of the bearing by more than 50% and provide up to 60% savings compared to the cost of a new bearing. For smaller bearings, such as the EZO miniature bearings supplied by SMB Bearings, it is not considered


cost effective. However, smaller bearings can benefit from services such as relubrication. Remanufacturing bearings also has a positive impact on the environment as it reduces the unwanted use of


natural resources and the disposal of components when they become damaged or fail. In addition, the energy requirement for remanufacturing is as low as 90% when compared to the production of a new bearing.


SMB Bearings


TESTING CONFIRMS BEARINGS CAN SURVIVE POWER PLANT BLACKOUT


Station blackout (SBO) tests have successfully been carried out by Michell Bearings on a thrust and guide bearing used within the reactor coolant pump at a new build nuclear power plant. The test demonstrated the bearing’s ability to survive a station blackout condition without the use of an externally powered high pressure oil injection system. Failure of the on-site power generators concurrent with the loss of offsite


power ultimately results in a station blackout condition as there is no on-site electricity available to power the high pressure oil injection system. In order to meet testing requirements, the bearing must be able to run down to a stop, under full load, and restart without any subsequent intervention. As part of the contract to supply six thrust and guide bearings, a


custom made test rig was constructed at the Michell Bearings site which was designed to closely replicate real world bearing operating conditions such as the possibility of a station blackout, where the bearings are required to shut down safely without the aid of electrical power to drive the reactor coolant pumps.


2 MAY 2021 | DESIGN SOLUTIONS 0 www.smbbearings.com


NEW SPHERICAL ROLLER BEARINGS


Offering productivity, reliability and load capacity, NSK’s new ECA series of spherical roller bearings feature a patented cage design which reduces internal stress and eliminates the need for a guide ring. The cage design also results in less stress as it balances form-fitting shape with cage bar strength, while a retainer ‘clasp’ on the tip of the cage bar prevents any potential for roller slip off. According to the company, these


supersede the CAM series, and ensure complete interchangeability with existing solutions. Notably, the next- generation, precision-machined solid brass cage features contoured roller


pockets to reduce any unnecessary roller motion during rotation. The bearings can accommodate


more rollers of a larger size, and they provide up to 47% higher dynamic load rating, and up to 22% more static load rating. Additional benefits include higher limiting speeds and a working temperature rated up to 200˚C. Potential applications for the new


ECA series range from conveyors, gearboxes and steelmaking machinery, through to presses and machinery used in mining.


NSK Europe www.nskeurope.com


Michell Bearings


www.michellbearings.com / DESIGNSOLUTIONS


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52