Basic Hydraulics Training Course

Lesson 1 - Principles of Hydraulics

Topics:

Force, weight, mass, pressure, work, power, and energy; Incompressibility; Nondiffusion; Hydrostatic pressure; Pascal's Law; Fluid power transmission; Bernoulli's principle

Learning Objectives:

– Explain the difference between absolute and gauge pressure.
– Demonstrate how power is calculated.
– Explain Pascal's Law.
– Describe the difference between laminar and turbulent flow.
– Name the main components of a hydraulic system.

Lesson 2 - Hydraulic Fluids

Topics:

Viscosity; Pour point; Fluid selection; Chemical properties; System contamination; Dissolved air; Foaming; Corrosion and rusting

Learning Objectives:

– List the most important properties of hydraulic fluids.
– Explain how viscosity is measured.
– Explain the meaning of the viscosity index.
– Describe the effect of fluid temperature on viscosity.
– Name the causes of corrosion and fluid oxidation.
– Identify various types of hydraulic fluids.

Lesson 3 - Strainers and Filters

Topics:

Contaminant removal; Strainer performance; Types of strainers; Fibrous and nonfibrous filter media; Magnetic media; Installation

Learning Objectives:

– Name contaminants found in hydraulic systems.
– Explain the difference between a strainer and a filter, and describe the main function of each.
– Describe the two basic types of filter/strainer media.
– Draw graphic symbols for strainers and filters.

Lesson 4 - Reservoirs and Accumulators

Topics:

Reservoir, air separation requirements; Baffles; Reservoir cooling methods and accessories; Accumulators; Schematic symbols

Learning Objectives:

– Explain the functions of fluid reservoirs.
– Explain the purpose of reservoir baffles.
– Describe various methods of counteracting high operating temperatures.
– Identify important accessories used with reservoirs.
– Demonstrate pressure ratio calculation for a differential-piston accumulator.

Lesson 5 - Hydraulic Pumps

Topics:

Pump varieties, functions, and selection; Gear, screw, cycloidal, vane, axial-piston, and radial-piston pumps

Learning Objectives:

– Name the main classification of hydraulic pumps.
– List factors affecting pump selection and pump performance.
– Define volumetric efficiency and overall efficiency.
– Identify the most common types of positive-displacement pumps, and describe their operation.

Lesson 6 - Piping, Tubing, and Fittings

Topics:

Fluid flow and velocity; Hydraulic pressure; Pressure loss; Steel pipe and fittings; Tubing and tube bending; Hoses; Hose fittings and couplings

Learning Objectives:

– Discuss the chief considerations in hydraulic line selection.
– Demonstrate how flow velocity and pressure loss are calculated.
– Explain pipe size schedules.
– Describe various types of fittings used in hydraulic systems.
– Explain the reason for using steel pipe.
– List the main advantages of tubing.

Lesson 7 - Directional Control Valves

Topics:

Valve classification; Automatic, two-way, check, pilot-operated, and spool valves; Hydraulic motors; NO, NC, holding valves; Symbols; Flow ratings

Learning Objectives:

– Explain the classification of directional control valves.
– Describe how manually operated valves work.
– Explain the difference between direct-acting and pilot-operated valves.
– Describe the operation of a check valve, a spool valve, a three-way valve, a four-way valve, and a rotary valve.
– Explain the difference between normally closed and normally open valves.

Lesson 8 - Pressure-Control Valves

Topics:

Poppet, spool, sequence, counterbalance, holding, unloading, and pressure-reducing valves; Shock suppressors; Flow-control valves

Learning Objectives:

– Explain the functions of a pressure-control valve, a pressure-relief valve, and a pressure-reducing valve.
– Describe the operation of a spool valve, a poppet valve, and a sequence valve.
– Explain the purpose of holding valves, unloading valves, and counterbalance valves.
– Name the operations performed by flow-control valves.
– Describe how pressure compensation and temperature compensation work.

Lesson 9 - Cylinders

Topics:

Double-, single-acting cylinders; Two-piston cylinders; Positional cylinders; Cylinder construction; Rings, seals, and packing; Cylinder mounting and selection; Flow capacity; Cushioning

Learning Objectives:

– Describe the purpose of a hydraulic cylinder, and explain how a double-acting cylinder works.
– Explain the difference between "pull-type" and "push-type" single-acting cylinders.
– Describe the construction of a hydraulic cylinder.
– Explain the various methods of mounting cylinders.
– Demonstrate how to calculate the flow capacity of a hydraulic cylinder.

Lesson 10 - Hydraulic Motors

Topics:

Performance specifications; Starting, running, and stalling torque; Volumetric efficiency; Hydraulic motor construction; Gear, vane, and piston motors

Learning Objectives:

– Explain the classification of hydraulic motors.
– Demonstrate how the torque of a hydraulic motor is calculated.
– Calculate the horsepower output of a hydraulic motor.
– Discuss cost factors and other considerations affecting motor selection.
– Describe the construction of a hydraulic motor.
– Explain the operating principles of a gear motor, a vane motor, and a piston motor