In present day motor production, it is usually an essential exercise to find methods to decrease the production cost to remain competitive. Ball bearings are among the primary elements which are used in the majority of high performance motors. The standard cost for a pair of ball bearing, which found in vacuum cleaner motor is around US$0.40 each, while the cost of oil-sintered porous bearings (porous bearings), which is a form of journal bearings, of equivalent size cost 3 times less. Therefore, it is economically attractive to change the previously mentioned ball bearings with the less expensive journal bearings. However, the application is usually not feasible because of material limitations, but latest advances in materials and surface engineering could make this a possibility. In existing work, experiments were designed to examine the feasibility of using journal bearings in high-speed motor applications…
Different journal bearing materials such as sintered bronze, sintered ferrite, modified-silica composite with carbon fibers, and advanced diamond-like carbon (DLC) coating deposited on shafts, are utilized within this research. The project was completed with a purposely-built test rig that could run up to 30,000 rpm. A typical embedded industrial journal bearing, which are bronze and ferrite journal sintered with oil, were utilised for evaluation purposes. Two industrial journal bearings operated with low friction coefficient when heavy load was employed. Having said that, low friction coefficient mainly takes place when light load was applied. Journal bearings were tested under both lubricated and dry conditions. It had been noticed that different journal materials being tested under lubricated condition, they could survive for 2 hours whatever shaft material was used. In these scenarios, it indicated that DLC coating didn’t make any substantial improvement on bearing performance. Yet, the application of DLC coating enhanced the journal life when they were tried under dry condition. Under such dry running conditions, shaft material and surface coatings impacted journal wear rate. It was suggested that with selected DLC coated shaft, the operating life of a sintered journal bearing could be extended even if the sintered bearing has inadequate oil lubricant…
The wear performance of journal bearing used in high speed applications downloads
Source: City University of Hong Kong