Release time : 2015-06-15 07:25:59
Newly presented cylindrical roller bearings for axleboxes PLC 410-15/16-2 of ZKL Brno, a.s. production program are equipped with polyamide-made cage. They meet the stipulations of CSN EN 12080 standard (Railway Applications - Bearings for Axleboxes - Roller Bearings) as well as the regulation of UIC (International Union of Railways) No. 510-1 containing technical requirements for railway cars travel gear. They are manufactured and supplied in conformity with special technical conditions guaranteeing a maximum quality of bearings for end users. The compliance of the product with technical requirements is documented by Product Certificate of Vyzkumny Ustav Zeleznicni (VUZ) Praha (Railway Research Institute).
These bearings do not require any extraordinary maintenance during operation. They are designed for maximum traveling speed of 160 km/hr with load up to 150 kN of wheel set or for speed of 120 km/hr of up to 225 kN load. Recommended quantity of lubricant for axlebox bearing (bearing box) is 0.6 kg.
The design of cylindrical roller bearings permits to accommodate all axially acting forces arising in railway operation without affecting the service life of the whole axlebox bearing.
The polyamide cages were developed in collaboration with SLB Brno, s.r.o. to fully conform to the European standard EN 12082. They are manufactured from polyamide 66 reinforced by 25% of glass fibers (PA 66 GF25). Compared with machined brass cages they are substantially lighter, which minimizes dynamic adverse conditions in bearings. Two sliding elements steel - polyamide have better sliding properties as compared with steel - brass. In addition to that polyamide better damps vibrations and noise. Thanks to technologic abilities the cage design has been solved to permit optimum passage of lubricant to rolling elements. Another advantage of bearings is self-lubricating capacity of polyamide. In case of lubrication deficiency the wheel set seizure does not occur so instantly as in case of brass cage bearings.
Axlebox bearings with cages made of polymer materials are used in all spheres of production and operation of railway vehicles. The company materials of world renowned bearing manufacturers as well as pieces of knowledge gathered o various trade fairs of railway technology obviously show that such bearings are being used in a greater extent than bearings with machined brass cage. It concerns not only Europe alone but America and Asia as well and the use of these bearings is not limited to cylindrical roller bearings for freight cars. On the contrary, the use of polyamide cages in taper roller bearing units and in most bearings for high speed rail cars became quite a commonplace.
Based on performed tests the independent inspector submitted that the bearings PLC 410-15/16-2 produced by ZKL Brno, a. s. are fully interchangeable with bearings PLC 410-15/16 with machined brass cage, without further operation tests.
The successful development of the said bearings permitted ZKL Brno to launch also development of further axlebox bearings in execution with new polyamide cage.