Grinding processes at Baltic Bearing Company – Riga

 

Grinding is a widespread and effective technological process of material machining, which is a type of abrasive processing. Grinding is also called the process of mass high-speed micro-cutting of the processed material by a large number of grains.

Cutting is the process of a material machining to give it a shape and dimensions of required accuracy using cutting off an excess material. During grinding, chips are cut off by separate grains which haven’t strict shape and location. Therefore, despite the same physical essence of the process, grinding has a range of differences in comparison with cutting: grains are randomly located on the working surface of the wheel; grains have non-correct geometric shape; depth of cutting of the single grain is small and variable along the arc of contact; large proportion of the friction work in the total grinding work; high cutting speed.

That’s why grinding process of the outer and inner rings to providing them technical characteristics in accordance with the drawings is the main and one of the most difficult processes in the cycle of BBC-R bearings production. Stability of the shape deviations of parts, their surfaces roughness, lack of concentration of internal stresses (grinding burns) and, as a result, the durability of the assembled bearing depends on the quality of the grinding technological process.

In addition, the grinding process should be effective, which is manifested in a decreasing of the machining main time, cutting forces, roughness of the machined surfaces and increasing of the grinding wheel lifetime.

The engineers of Baltic Bearing Company-Riga have developed and implemented range of solutions and developments for increasing stability and efficiency of grinding process:

– drawings, technical documentation and technological processes of bearing parts grinding at “Baltic Bearing Company-Riga” are developed on the basis of the latest trends in the machine-building industry;

– the latest equipment (semi-automatic machines and CNC machine lines) and software (Siemens, Mitsubishi) made specifically for the bearing industry are used for stable processing quality, as well as abrasive tools from leading manufacturers (Tyrolit, Norton, etc.), which provide the best technical properties and performance indicators.

– special solutions have been introduced at certain operations, for example, using of combined grinding wheels of various grain sizes for centerless grinding of the outer cylindrical surface of rings.

– a system for monitoring the abrasive tool wear and its automatic dressing during grinding operations is used on CNC machines. Grinding tool wear and machining quality are monitored by a sensor system during grinding, as well as by in-line monitoring of rings after grinding operations;

– cutting oils are selected and produced independently on the basis of concentrates (FUCHS, BECHEM).

These introduced technologies have made possible:
– to increase the productivity of processing;
– to reduce the energy intensity of the process;
– to reduce the thermal factor of the grinding process and the probability of burns occurrence;
– to reduce the consumption of cutting oils;
– to effect on the process stability (Cp, Cpk = 1.49..1.51);
– to provide high quality of grinded surfaces.

Constant development of technologies and improvement of bearing production processes is one of the strategic goals of “Baltic Bearing Company-Riga”