Gearing contact is which one of the following?

The correct answer is option B) Sliding contact, only rolling at the pitch point.

Explanation:

Gearing contact refers to the interaction between two gears in a gear transmission system. It determines how the teeth of the gears engage and transmit motion and power. Gearing contact can be categorized into various types based on the nature of contact between the gear teeth.

Rolling Contact:
In rolling contact, the two gear teeth roll over each other without any slipping or sliding. This is the most efficient type of contact as it minimizes friction and wear. However, in practical situations, perfect rolling contact is not always achievable due to manufacturing tolerances and other factors.

Sliding Contact:
In sliding contact, there is sliding or relative motion between the gear teeth. This can occur when the gear teeth are not perfectly aligned or when the gears are subjected to heavy loads. Sliding contact results in higher friction and wear compared to rolling contact.

Rolling and Sliding at Each Point of Contact:
This option refers to a combination of rolling and sliding contact at each point of contact between the gear teeth. In this case, the gear teeth experience both rolling and sliding motion simultaneously. This can happen when the gears are misaligned or when there are variations in tooth profiles. Rolling and sliding at each point of contact can lead to increased friction, wear, and energy loss.

Sliding Contact, Only Rolling at the Pitch Point:
The correct answer is option B, which indicates that the gears have sliding contact between their teeth, but only rolling contact occurs at the pitch point. The pitch point is the point where the gear teeth come into contact and transmit motion. At the pitch point, the gears achieve rolling contact, which minimizes friction and wear. However, as the teeth move away from the pitch point, sliding contact occurs, resulting in higher friction and wear.

In summary, gearing contact is a combination of rolling and sliding contact, with rolling contact occurring only at the pitch point. This combination ensures efficient power transmission while minimizing friction and wear.