Hydraulic Systems & Pneumatics Flashcards

What does Pascal's Law state as it applies to hydraulic systems?

Answer: Pressure applied to a confined fluid is transmitted equally in all directions

Pascal's Law states that pressure applied to a confined, incompressible fluid is transmitted undiminished in all directions throughout the fluid, which is the fundamental principle behind all hydraulic systems.

What is the primary function of a hydraulic pump in a construction equipment system?

Answer: To convert mechanical energy into hydraulic flow

A hydraulic pump converts mechanical energy from an engine or motor into hydraulic flow, which creates the pressure and force needed to move hydraulic actuators and perform work.

Which type of hydraulic pump is most commonly used in heavy construction equipment due to its ability to handle high pressures and provide variable displacement?

Answer: Piston pump

Piston pumps are most commonly used in heavy construction equipment because they withstand high pressures, offer variable displacement, and provide high volumetric efficiency under demanding operating conditions.

What does hydraulic fluid viscosity refer to in the context of system performance?

Answer: The fluid's resistance to flow, commonly described as its thickness

Viscosity refers to a fluid's resistance to flow, often described as its thickness, which directly affects lubrication quality, heat generation, and overall hydraulic system performance.

What is the purpose of a hydraulic relief valve in a construction equipment circuit?

Answer: To limit maximum system pressure and protect components from damage

A relief valve limits maximum system pressure by diverting excess fluid back to the reservoir when pressure exceeds the preset limit, protecting pumps, valves, cylinders, and hoses from damage.

In a hydraulic system, what is the primary function of a directional control valve?

Answer: To control the direction of fluid flow to actuators

A directional control valve routes hydraulic fluid to different ports of an actuator, determining which direction a cylinder extends or retracts and which way a hydraulic motor rotates.

What is cavitation in a hydraulic system and why is it harmful?

Answer: Vapor bubbles form in low-pressure zones and collapse violently in high-pressure areas, causing component damage

Cavitation occurs when pressure drops below the fluid's vapor pressure, forming vapor bubbles that collapse violently in high-pressure zones, causing noise, vibration, pitting, and serious damage to pump and valve components.