Bearing manufacturing process layout comprises:

1. 1st operations

2. Heat treatment

3. Grinding

4. Assembly

Raw Material: Bars or tubes of 100 Cr6 type steel.

The first operations :

There are two main types of 1st Operation: Removal of material (turning or bar turning)

o Bar Turning/Turning : Removal of material when cold, using a cutting tool (knurl or tip) on a multi-spindle turning machine. Turning is the process whereby a single point cutting tool is parallel to the surface. It can be done manually, in a traditional form of lathe, which frequently requires continuous supervision by the operator, or by using a computer controlled and automated lathe which does not. This type of machine tool is referred to as having computer numerical control, better known as CNC. And is commonly used with many other types of machine tool besides the lathe.

o Turning: Technique similar to bar turning but performed on a single spindle turning machine. When turning, a piece of material (wood, metal, plastic, or stone) is rotated and a cutting tool is traversed along 2 axes of motion to produce precise diameters and depths. Turning can be either on the outside of the cylinder or on the inside (also known as boring) to produce tubular components to various geometries

Deformation (pressing, forging or rolling)   o Pressing: Cold working of the material (steel sheet) and cutting out (technique

similar to forging) o Forging: Working a slug of previously heated material. Forging is the shaping of

metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging. Forged parts usually require further processing to achieve a finished part.

o Rolling: In metalworking, rolling is a metal forming process in which metal stock is passed through a pair of rolls. Rolling is classified according to the temperature of the metal rolled. If the temperature of the metal is above its recrystallization temperature, then the process is termed as hot rolling. If the temperature of the metal is below its recrystallization temperature, the process is termed as cold rolling.

Heat Treatment:

Soften the metal prior to shaping;

Relieve the effects of strain hardening that occurs during cold forming;

Achieve the final strength and hardness required in the finished product as one of the end manufacturing processes.

At each of the three steps, different processes are available, depending on the product.

o Heating 850 °C: (Austenitizing) to alter the structure of the material. Austenitization means to heat the iron, iron-based metal, or steel to a temperature at which it changes crystal structure from ferrite to austenite. An incomplete initial austenitization can leave undissolved carbides in the matrix.

o Quenching 40 °C: Rapid cooling to fix the structure of the material and thus increase hardness.

o Tempering 170 °C: Reheating" to reduce the effects of thermal shock (quenching) inside the structure and stabilize the material.

Grinding

Grinding is used to give the ring blanks their "final" shape and improve surface condition (roughness).Grinding is used to produce a smooth finish on flat surfaces. It is a widely used abrasive machining process in which a spinning wheel covered in rough particles (grinding wheel) cuts chips of metallic or non-metallic substance from a work piece, making a face of it flat or smooth.

Various mills are used to perform several operations:

o Surface Grinding:

o Outer ring outer diameter grinding:

o Inner ring inner diameter grinding:

o Inner ring outer diameter grinding:

o Outer ring outer diameter grinding

Super finishing:

Superfinishing, also known as micromachining and short-stroke honing, is a metalworking process that improves surface finish and workpiece geometry. This is achieved by removing just the thin amorphous surface layer left by the last process with an abrasive stone; this layer is usually about 1 μm in magnitude. Superfinishing, unlike polishing which produces a mirror finish, creates a cross-hatch pattern on the workpiece.

  Assembly – End of process layout

Operations involving:

o Assembly of various items,o Performing additional functions (greasing, marking, etc.)o During each of these steps, the bearing manufacturing process layout is carried out in

compliance with total quality (self-inspection, SPC and TPM).