Types of Gears Used In Pumps:

There are two categories of gears used in gear pumps in addition to the simple spur gear. One type is the helical gear. A helix is the curve generates while a straight line moves up or down the surface of a cylinder. Another type is the herringbone gear. A herringbone gear is composed of two helixes spiraling in different directions from the center of the gear. Helical, spur, and herringbone gears are display in Figure.

The helical gear pump has benefits over the simple spur gear. Within a spur gear, the whole length of the gear tooth engages at the similar time. In a helical gear, the point of engagement moves along the length of the gear tooth as the gear rotates. This creates the helical gear operate along with a steadier discharge pressure and fewer pulsations than a spur gear pump.

The herringbone gear pump is also a change of the simple gear pump. Its principal difference within operation from the easy spur gear pump is in which the pointed center section of the space among two teeth starts discharging before the divergent outer ends of the preceding space complete discharging. This overlapping tends to gives a steadier discharge pressure. A power transmission from the driving to the driven gear is also quieter and smoother.

Figure: Types of Gears Used In Pumps