Which description best defines a rotary pump?

Which description best defines a rotary pump?

• A. A turbine rotor drives the flow
• B. Two gears mesh and rotate in opposite directions
• C. A single piston moves back and forth
• D. A diaphragm pump uses flexible chambers

Answer: (B)

Rotary pumps move fluid by continuously rotating components that trap and carry the liquid in pockets as they turn. The gear-type rotary pump does this with two gears that mesh and rotate in opposite directions. As the gears spin, fluid is trapped between the gear teeth and the housing, carried around from the inlet to the outlet, and expelled in a steady, ongoing flow. This is the hallmark of a rotary pump: constant rotation producing steady discharge without the back-and-forth motion seen in reciprocating designs. In contrast, a single piston moving back and forth describes a reciprocating pump, which uses linear motion to draw in and push out fluid. A diaphragm pump relies on flexible chambers that expand and contract to move liquid, also a non-rotary mechanism. A description involving a turbine rotor driving the flow points to a turbine-driven or non-gear pump setup, not a gear-based rotary pump. So the gear-gear, opposite-direction rotation definition best captures what a rotary pump is.

Rotary pumps move fluid by continuously rotating components that trap and carry the liquid in pockets as they turn. The gear-type rotary pump does this with two gears that mesh and rotate in opposite directions. As the gears spin, fluid is trapped between the gear teeth and the housing, carried around from the inlet to the outlet, and expelled in a steady, ongoing flow. This is the hallmark of a rotary pump: constant rotation producing steady discharge without the back-and-forth motion seen in reciprocating designs.

In contrast, a single piston moving back and forth describes a reciprocating pump, which uses linear motion to draw in and push out fluid. A diaphragm pump relies on flexible chambers that expand and contract to move liquid, also a non-rotary mechanism. A description involving a turbine rotor driving the flow points to a turbine-driven or non-gear pump setup, not a gear-based rotary pump. So the gear-gear, opposite-direction rotation definition best captures what a rotary pump is.