Bearing rings – how it's done?

HARP bearings are high-tech items subject to a strict production path. Earlier we have already talked about manufacture of rolling elements, conducted by our suppliers. Today we will talk about organization of production of ball bearing rings at the Kharkiv Bearing Plant (HARP).

Production of blanks of rings of small sizes takes place at the automatic turning site. Production of medium-sized ring blanks from a preheated steel bar is carried out at the forging and annealing site.

After the incoming inspection of steel bars at automatic turning site, the bars are cut into piece blanks (by means of automatic disc and band saws HCS-90, HCS-130, HBP-340) and turned (by means of CNC machines PAB-130, PAB-160, GA2000/300, LVT-300M). After that, the products undergo control of geometric parameters.

At the forging and annealing site, the bars are first subjected to induction heating and cut into piece blanks which are delivered to the first forging position. Hot forging (lines L-324) includes the following stages: upset, pre-forming, final forming, separation of forgings. It should be noted that during hot forging, as a result of plastic deformation, metal fibers have the same profile as the finished product and during subsequent turning, metal fibers are not cut. Such technology can significantly improve the quality of finished products, their wear resistance and service life. Forgings are cooled and delivered to spheroidizing annealing (A/SP-1200 units), after which they are transported to automatic turning site for turning and cold rolling.

Production of hot-forged blanks with subsequent annealing in spheroidizing medium, machining on CNC machines and cold rolling allowed HARP to reach the world standards for products for the automotive industry.

The next stage is heat treatment. The rings are heated in a gas-proof atmosphere up to 850°C and quenched in oil at temperature of + 40°C. After that rings pass low-temperature tempering and quality control. Now the products are ready for grinding at the grinding-modular site.

At the grinding-modular site, the products undergo the following production chain: flat-grinding / end-grinding, centerless-grinding, bore grinding, quality control, raceway grinding, quality control, laser marking, quality control, raceway superfinishing, flaw detection.

After that, the rings are transported to the assembly site. 

To be continued…