Roulements - 20/05/2009
Developed specifically for applications with heavy or shock loads, of the type encountered in jaw and cone crushers, NSK’s CA series of double row spherical roller bearings are manufactured with a machined brass cage to combat the effects of vibration, operating fatigue, wear and corrosion. The CA bearings have high load rating superior durability and are resistant to wear.
Extending the CA range into harsh vibrating applications is NSK’s CA-VS series of spherical roller bearings. VS series bearings have been optimised for use in harsh vibrating applications. Their vibratory specification builds upon the extended load and life benefits of the standard CA construction with an optimised design that provides improved fatigue strength against the vibration and shock loads conditions encountered on screens, feeders and compactors.
In addition to addressing the problems of heavy shock loading and vibration, NSK is also providing significant benefits to mining and extraction industries, by reducing maintenance and energy costs, and enabling product downsizing. The new bearing range that provides these benefits is the HPS™ series. HPS bearings offer innovative performance with twice the running life, compared to conventional SRB of the same size, and a maximum limiting running speed that has been improved by up to 20%.
Also providing improved performance benefits, this time as a result of extra rollers in their design, is NSK’s EW/EM series of cylindrical roller bearings. These bearings are used in the differentials of off-road trucks; the transmissions and torque converters of crawler dozers; the transmissions of wheel loaders; and the speed reducers and hydraulic pumps used on hydraulic excavators.
The EW/EM series CRB are capable of carrying particularly large radial loads and are also suitable for high-speed applications. The EW series features a pressed steel cage, and the EM series a one-piece machined brass cage. Both of these cage designs offer high-load ratings for standard size bearings, in addition to excellent and longer operating life - approximately twice that of conventional CRB.
Additional equipment areas that are also benefiting from improved reliability and longer operating life as a result of NSK’s bearing development programme for mining are conveyors, feeders and general handling equipment, crane sheeves and mobile gantries. NSK’s plummer block, ball bearing units are used widely in mining and minerals extraction - on conveyors, feeders and general handling equipment - due to their tough construction and, timesaving, easy installation and mounting benefits.
NSK has built-upon the robustness of these bearings with a design that includes high efficiency steel reinforced seals and cast iron bearing covers for added protection against dust.
Also benefiting from NSK’s focus on improving bearing life in mining and extraction applications is a new range of full- complement cylindrical roller bearings for use in crane sheeves. These bearings offer advanced levels of ingress protection with a new sealing system, which minimises grease leakage and increases resistance to the entry of water and other foreign substances.
Designed to provide maximum reliability and operating life in the difficult environments encountered in mines, quarries, ports and building sites, the new full complement bearings are supplied with phosphate surface treatment to improve their resistance to corrosion.
The ability of the bearings to provide reliable life in arduous environments is also enhanced by specially machined holes, which are provided on the inner and outer rings of the bearings to allow grease replenishment, even with the bearing in situ.