Hydraulics and Fluid Dynamics Flashcards

Two hydraulic cylinders are connected in parallel to the same pump. Compared to a single cylinder, what is true about force and speed?

Answer: Force per cylinder is the same, but each extends at half the speed

In parallel, pressure (and thus force) is the same, but pump flow is split, so each cylinder extends more slowly.

What happens to system pressure when a hydraulic cylinder reaches the end of its stroke and cannot move further?

Answer: Pressure rises until the relief valve opens

With no movement to absorb pump output, pressure builds rapidly until the relief valve opens to protect the system.

Which factor most affects the viscosity of hydraulic oil in real-world operation?

Answer: Temperature

Viscosity drops significantly as temperature rises, which is why hydraulic systems specify oil grades for operating temperature ranges.

A flow control valve is installed in a hydraulic circuit. Its primary function is to:

Answer: Regulate the speed of a hydraulic actuator

Flow control valves restrict or allow fluid flow to control actuator speed, not pressure or direction.

Why is it important to bleed air from a hydraulic system?

Answer: Air is compressible and causes spongy, unpredictable actuator movement

Trapped air compresses under pressure, creating a cushioning effect that makes cylinder movement feel soft and inconsistent.

A gear pump operates by:

Answer: Meshing gear teeth to trap and move fluid from inlet to outlet

Gear pumps use intermeshing gears to carry fluid in the spaces between teeth from the suction side to the discharge side.

What is the primary purpose of a hydraulic filter?

Answer: Remove contaminant particles that cause wear in valves and pumps

Filters remove solid particles from the fluid to prevent abrasive wear and clogging of precision hydraulic components.