Week 2 2_hydraulic_systems_component

Power pack

Components of a Hydraulic System

Tank/resevoir

Pump

Piping system

Power supply/

electric motor

Actuator

Valves

Consist of three main components

◦Reservoir

◦ Electric motor

◦ Pump

Through hydraulic reservoir the hydraulic system is

supply with fluid means that the reservoir stores the

required quantity of fluid.

The reservoir performs important functions such:

• Dissipating heat through its walls

• Conditioning the fluid by helping settle the

contaminants

• Relief of air from the systems

• Providing mounting support for the pump and other

components.

A proper tank has the following:

• Baffle plate for preventing the return fluid from

entering the pump inlet

• For maintenance purposes a reservoir should

have an inspection cover

• A filter breather for air exchange

• Level indicator for checking the fluid level

• Connections for suction discharge and drain

lines.

Inspection

cover

Used to drive the hydraulic pump

Mechanical device that converts mechanical

power into hydraulic energy.

Generates flow with enough power to overcome

pressure induced by the load.

Its mechanical action creates a vacuum at the

pump inlet which allows atmospheric pressure to

force liquid from the reservoir into the inlet line to

the pump.

Delivers this liquid to the pump outlet and forces it

into the hydraulic system.

The control of hydraulic power in hydraulic power

systems is carried out by means of control valves.

Types of hydraulics valve ◦ Pressure control valves (PCVs)

◦ Directional control valves (DCVs; direct- and pilot-

operated)

◦ Flow control valves (FCVs)

◦ Check valves

To drive loads by converting the hydraulic power into mechanical power.

The mechanical power delivered to the load is managed by controlling the fluid pressure and flow rate, by using various hydraulic control valves.

The hydraulic actuators are classified into three main groups according to motion type: ◦ Hydraulic cylinders, performing linear motion

◦ Hydraulic motors, performing continuous rotary motion

◦ Hydraulic rotary actuators, performing limited angular displacement

The elements of the hydraulic system are interconnected by

hydraulic transmission lines, through which the hydraulic

liquid flows.

These lines are either rigid tubing or flexible hoses. The rigid

tubing lines connect fixed nonvibrating elements, and the

flexible hose lines connect moving parts.

Regardless of their simple design, the hydraulic tubes have

an important effect on the steady state and transient behavior

of the system.

Transmission lines affect system performance in the following

ways:

◦ • Hydraulic friction losses; hydraulic resistance of lines

◦ • Hydraulic local, or secondary, pressure losses

◦ • Oil compressibility and elasticity of pipe material