Internal Gear Cutting Operations

Internal gears are gears with teeth on the inside diameter rather than the outside diameter. They are commonly used in various applications such as gearboxes, planetary drives, and pumps. The process of cutting internal gears involves removing material from the blank to form the desired gear profile. There are different methods for performing internal gear cutting operations, and in this case, the correct answer is option 'C' - shaping with a pinion cutter.

Shaping with Pinion Cutter
Shaping is a machining process that involves removing material from a workpiece using a cutting tool. In the case of internal gear cutting, a pinion cutter is used, which is a type of gear-shaped cutting tool. The pinion cutter is mounted on the shaper machine, and the workpiece, which is the gear blank, is mounted on the machine's worktable.

The pinion cutter is then fed into the workpiece, generating the desired gear profile. The cutting action of the pinion cutter removes material from the blank to form the teeth of the internal gear. The shape and size of the pinion cutter are designed to match the desired gear profile.

Advantages of Shaping with Pinion Cutter
- Flexibility: Shaping with a pinion cutter allows for the production of internal gears with various tooth profiles and sizes.
- Accuracy: The shaping process can achieve high precision and accuracy in cutting the gear teeth.
- Cost-effective: Shaping is a cost-effective method for cutting internal gears compared to other methods such as hobbing, which requires specialized equipment.

Other Methods
- Milling: Milling can also be used to cut internal gears. However, it is more commonly used for external gear cutting operations.
- Shaping with Rack Cutter: Shaping with a rack cutter is another method for cutting internal gears. In this process, a rack cutter with the shape of the gear teeth is used to cut the teeth into the gear blank.
- Hobbing: Hobbing is a process used for both external and internal gear cutting operations. It involves using a hob, which is a cylindrical cutting tool, to generate the gear teeth by continuous rotation and feeding motion.

In conclusion, the internal gear cutting operation can be performed by shaping with a pinion cutter. This method offers flexibility, accuracy, and cost-effectiveness in producing internal gears with various tooth profiles and sizes.