Influence of Grain Shape in Grinding Wheels on the Machining Quality of Bearing Rings

The quality of grinding of bearing races is related to their performance and durability. The aim of this work is to establish how the machining quality of bearing rings depends on the characteristics of grinding wheels, in particular, on such a parameter as the shape of abrasive grains. Several batches of experimental grinding wheels were made, containing grains of different shapes (from isometric to lamellar varieties). Quantitatively, the shape of the grains was estimated by the shape factor parameter (SF), which is equal to the ratio of the diameters of inscribed and circumscribed circles in the contours of the used grains. The shape factor was determined using a scanner or a digital microscope and a special computer program. The tests were carried out on circular, plunge, and finishing grinding, using coolant, on a SIW 4E machine in a bearing factory. The machining quality of the bearing rings was assessed by studying the microstructure, microhardness and roughness of their bearing races. The durability of grinding wheels was determined by the number of machined rings before maximum tool wear. It has been established that by a differentiated approach to the choice of grain shapes in the wheel, it is possible to significantly increase its operational capabilities: increase the microhardness of the ground surfaces, reduce the roughness of processing, and increase the durability of grinding wheels.

Recovery of Residues of Surface and Emulsion Waste Water Treatment at a Bearing Factory

The directions of utilization of production wastes of the second level, namely, residues of surface and emulsion waste waters treatment of a bearing factory, are given. The results of studies of a new composition of asphalt concrete mixture obtained on the basis of foam, sludge from the treatment of surface water and oily sludge from the treatment of emulsion wastewater from a bearing factory are presented. A technological scheme for the reuse of waste water from surface and emulsion wastewater treatment at a bearing factory has been developed.

Reuse of Treated Surface Runoff at a Bearing Factory

The results of studies of cutting fluids on three types of solvents are presented: distilled water, tap water and treated surface effluents of the factory. It has been proven that replacing tap water with treated surface wastewater when preparing soda-nitrite solutions does not affect the operational and functional properties of the coolant. The possibility of using the treated surface runoff of a bearing factory for the preparation of coagulant solutions for the purpose of using it in the purification of emulsion wastewater has been confirmed. Shown are the directions of recycling waste treatment of the surface runoff of the factory, in particular in the construction industry in the production of asphalt concrete.

War and Vanity

In my childhood, visits to Gothenburg would always include a long (it seemed at the time) tram ride with my mother, from the centre of town to the north-eastern districts, past the old, red brick, ball-bearing factory of SKF to the vast Kviberg Cemetery to put flowers on my grandmother’s grave. I never ventured on any longer excursions among the neat flower-decorated graves on these well-kept lawns, but had I done so I would perhaps have discovered a different, more uniform, part of the cemetery that relatives seldom visited: the war graves. War graves form a somewhat unexpected discovery in the suburbs of a country that was neutral in both world wars, but there it is. Among the mostly German, American, and British graves we find, in the Commonwealth section, that of Arthur Cownden who, at 17, was probably the youngest to be buried there. He was boy telegraphist on a Royal Navy destroyer, and on the morning of 1 June 1916 his body was washed ashore close to the small fishing village of Fiskebäckskil on the Swedish west coast. His ship, the HMS Shark , was one of many British losses during the preceding day’s Battle of Jutland—the only clash between the main forces of the Royal Navy and the German Hochseeflotte during World War I. By all accounts this was a terrible battle, with loss of lives in the thousands on both sides, and one of the largest naval battles ever fought. The Battle of Jutland remains somewhat controversial for two reasons: the enduring argument between the two British commanders, David Beatty and his superior John Jellicoe, and the purported role of the Royal Navy’s smokeless gunpowder cordite in the sinking of a number of its own ships. We have no business with naval tactics, but the cordite question is related to one of the lesser-known supply problems of World War I, that of acetone. You may be familiar with this molecule as nail varnish remover, but perhaps you also know the disastrous effect it has on the glossy surface of cars.