🔍 Key Concepts

• Axial-piston pump construction – how many pistons are typically spaced around the cylinder block for smooth, continuous flow • Even flow and balance – why designers choose certain odd numbers of pistons to reduce pulsation and vibration • Marine hydraulic practice – common piston counts used in variable-stroke axial pumps on ships

💭 Think About

• Think about why pump designers prefer an odd number of pistons and how that affects pressure pulsations in one revolution • Consider which pair of numbers would give reasonably smooth flow while still being practical in size for marine machinery • Ask yourself: as pump capacity increases, does the typical number of pistons generally go up or down?

✅ Before You Answer

• Confirm that the number of pistons in an axial-piston pump is usually an odd number for better flow characteristics • Visualize the pistons spaced evenly around a circle – which option gives a realistic, balanced mechanical layout for a marine-size pump? • Eliminate any answer that seems too few pistons to give smooth flow for a variable-stroke axial-piston pump in typical marine service