j4011 – pneumatic & hydraulic (hydraulic basic)
DESCRIPTION
pneumatic &hydraulic presentationTRANSCRIPT
JJ512 – Pneumatic and
Hydraulic
Prepared by Hanizam bin Ibrahim
LEARNING OUTCOME
The student will be able to:State ISO standard symbols of hydraulic
components.Sketch the construction and describe the
application of gear, vane, piston and screw pump.
Describes a method to moving the valve.Sketch and describes the application of control
valves.Sketch and stated the purpose of hydraulic
actuators.
INTRODUCTION The hydraulic system is widely used in the
construction of heavy machinery such as bulldozers, tractors, drill machines, trucks and others.
Hydraulic system is better and efficient than Pneumatic systems in the construction of heavy machinery and use fluid as the medium.
Working principal of hydraulic systemThe pump is used to suck hydraulic fluid that
has driven by an electric motor to produces the flow of fluid.
Direction and flow rate of fluid is controlled by valves.Actuators are used to convert fluid pressure into mechanical movement (Power).
Standard symbols of hydraulic componentsNo Component Symbol
1 Fixed displacement hydraulic pump
2 Variable displacement hydraulic pump
3 Fixed displacement hydraulic motor
4 Variable displacement hydraulic motor
5 Fixed displacement hydraulic pump motor
6 Pneumatic motor
7 Variable displacement hydraulic pump
Standard symbols of hydraulic components (continue..)No Component Symbol
8Oscillating hydraulic actuators
9Oscillating pneumatic actuators
10Single acting cylinder without springs
11
Single acting cylinder with springs return
12Ram cylinder
13Double acting cylinder with single rod
14Double rod cylinders
15Cylinder with a single type of cushion
16 Cylinder with twin-cushion type
Standard symbols of hydraulic components (continue..)No Component Symbol
17 Single acting telescopic cylinder
18 Pressure relief valve
19 Flow control valve
20 Adjustable flow control valve
21 2/2 directional control valve
22 4/3 directional control valve with mid position close
23 3/2 directional control valve
24 3/3 directional control valve with single solenoid and spring return
25 5/2 directional control valve
26 Check valve
Standard symbols of hydraulic components (continue..)No Component Symbol
27 Shuttle valve
28 Adjustable flow control valve and check valve
29 Pressure switch
30 Filter
31 Diaphragm-type cylinder
32 Direct pilot
33 Indirect pilot
34 Spring
35 Adjustable spring
Hydraulic circuit
Cylinder
Directional Control Valve
Relief valve
Motor
Tank
Filter
Pump
Accumulator
Function of hydraulic components1. Tank (Basic)
Hold the hydraulic fluid. Act as a cooling system. Filter the dirt and contaminant in the system.
2. Filter (Accessory) filter the dirt in the hydraulic fluid before entering
the suction of pump.
3. Pump (Basic) Distribute the hydraulic fluid to the entire system.
4. Motor (Basic) Produce the power to drive the pump change the electrical energy to mechanical energy.
M
Function of hydraulic components5) Accumulator (Accessory)
Keep/ store the system pressure. Absorbing the vibration. stabilize the system pressure.
6) Valve (Basic) To regulate pressure in the circuit. To control the direction of
hydraulic To control the flow rate of the
hydraulic fluid.
Function of hydraulic components7) Pressure relief valve (Accessory)
To limit the maximum pressure of hydraulic fluid.
To prevent pump from damage cause by over pressure.
8) Cylinder (Basic) To produce the power to work for
linear motion.
Hydraulic Pump
IntroductionAll pump and motor used in hydrostatic is
a positive displacement type where leakage is minimal and can be ignored.
Pumps and motors can be divided into two main types1. Fixed displacement 2. Variable displacement.
Introduction Pumps can be divided into several types
as follows: -
PUMP
GearRam / Vane / Blade
Piston Screw
Gear pumpUsing two or more pairs of gears and it is
installed in a steel box with input (inlet) and output (outlet) channels.
The two gears in a pair are the same size.The compression occur between the gear and
housing wall. The rotation of gear will be increase the value of pressure and temperature.
Construction of gear pump
Inlet Outlet
Driven
Driver
Housing
Ram / vane / blade pumpConsisting of pairs of rotors with some free
sliding vane rotor with radial slit.Liquid will flow into the inlet when the space
between the casing and the rotor vane rotor becomes large and the liquid is removed from the room next door when space becomes smaller as the rotor rotates.
Construction of vane compressor
Inlet
Slotted rotorVane
Direction of rotation
Outlet
Screw pumpIt is durable because of the fluid used to act
as a safeguard against leakage. It can be used if the load applied to it does
not change. This type of pump requires oil filters mounted
in series at the outlet.
Construction of screw pump
Rotation
Outlet Inlet
Piston pumpPiston pumps are mostly used on systems with
operating pressures above or equal to 140 bar. The main feature of the piston pump is high
efficiency at high pressure. This is very important when a constant flow
without pressure changes. There are two types of multi-piston hydraulic
pump: 1. Axial type.2. Radial type.
Construction of piston pump
Bent Axis
Axial Plate Shaking
Types of Axial Piston pump
Construction of piston pump
Types of Radial Piston pump
Valve
Method of Moving a ValveThere are three (3) method of moving a valve:
1. Mechanical – roller and manual2. Pneumatic – pilot3. Electrical – solenoid
Method of Moving a Valve
Service Unit (FRL)
Air filterPressure regulatorLubricator
LubricatorPressure regulator
Air filter
Types of control valveThere are three (3) types of control valve:
1. Pressure control valve 2. Directional control valve3. Flow control valve4. is used to limit or control the system
pressure. It reduces the burden of a pump pressure or the temperature of the oil before the oil flow to the hydraulic circuit. Kawalann valve pressure can be divided into five types, namely: - relief valve and check
Pressure control valve To limit or control the system pressure. Reduces the burden of a pump pressure or
the temperature of the fluid before the fluid flow to the hydraulic circuit.
Can be divided into five types, namely: -1. Pressure relief valve2. Pressure reducing valve3. Pressure sequencing valve4. Pressure unloading valve5. Counter balance valve
Pressure control valve
1. Pressure relief valve 4. Pressure reducing valve
2. Pressure sequencing valve 5. Pressure unloading valve
3. Counter balance valve
Directional control valve Directional control valve is used as a path or
piloting the hydraulic fluid in the system. It has various types such as:
1. Rotor valve
2. Spool valve3. Open center and closed center valve4. Combination / multi spool valve
1. Rotor valve It is commonly used as a pilot valve to continue the
flow to other valves. Rotary-type directional control valve using a valve
rotors with 4-way oil output and input. These rotors have holes that can be connected to
the hole in the valve body when the rotor is rotated. This rotor is driven by a lever (lever) on hydraulic or
electrically.
2. Spool valve It was used to start or stop the direction of fluid in
the system. These valves could be control by manual, electrical
or hydraulic pilot and acting on the end of the spool. Tool setter is always used to determine the position of the valve in each operation.
Neutral position
Open center system - the pump will move continuously even directional control valve is in the neutral position. Hydraulic fluid will continue to flow from the pump through the control valve then return back into the tank.
Closed center system - the pump will stop when the control valve is in neutral. Directional control valve will stop the flow of fluid from the pump and cause the pump to stop running. Pump will be switched off by disconnecting the supply current to turn the motor pump. The switch is controlled by fluid pressure.
3. Open center and closed center valve
4. Combination / multi spool valve Two or more spool valve can be used in a group of
multi-function valve for operation. Construction of the spool valve depends on the
number of grafts in the operating valve.
Flow control valve Flow control valve can be adjusted in the
following manner: Limiting flow in or out of the component
which speed is easily adjusted. This type of valve is no compensation.
Change the flow direction to or from the component which speed is easily adjusted. This type of valve is usually compensated.
Can be divide into two (2) types:1. non-compensated valves2. compensated valves
1. Non-compensated valves Non-compensated valves will not be affected on the
pressure change. Commonly used when precise/accurate flow control is not
required. Examples of this valve is
1. Needle valve It was a simple limiter. When the needles were turned down, the flow will stop. When the needles moved up to open the screw, the orifice hole will open slightly and allow flow through it. When the screw is fully extended, the full flow can be created.
2. Globe valve.This valve is not sensitive to pressure changes. It is very simple and can be adjusted to obtain the desired flow rate.
1. Compensated valves Compensated valve will try to maintain the flow
rate even flow into the valve changed. Examples of this valve is
1. Compensated flow-control valveThis type of valve operates on the idea that the existing orifice size on components controlling the pressure drop at the orifice, causing the flow rate to be fixed. Orifice hole size at the end is connected to the spring. If the flow through the orifice is increases, pressure will also increase. The addition of flow will cause the spool moves to the right and hit the spring.
2. Bypass Flow regulatorCommonly used in open center system. By using this type of valve oil removed by pumps will be used to perform work on the main function.
Actuator
The construction and function is same as pneumatic actuator except the medium is hydraulic fluid.
The actuator change the hydraulic power to mechanical power.
Can de divided into two types:1. Cylinder for linear motion2. Motor for rotation
Introduction
Cylinder1. Single acting cylinder2. Double acting cylinder
Motor3. Screw4. Piston
a. Axialb. Radial
5. Vane/ram/blade6. Gear
a. External Gear b. Internal gear
** All construction and application of motor is same as pump except gear motor.
Gear MotorWidely used because it is
easy and economical. Normally it is used to move
a small component. Motor gear rotates in
clockwise or vice versa. It has a permanent shift. There are two (2) types
gear motor 1. external gear motor 2. internal motor gear.