Hydraulic System Design (Hydraulic Project Service)

Hydraulic System Design (Hydraulic Project Service)

Hydraulic power unit, hydraulic block, central lubrication systems and hydraulic cylinders are designed by our experienced team with Solid Works 3D solid modeling software.

Hydraulic units, valve stands and battery systems from 20 liters to 10000 liters are designed and manufactured in our company in order to provide hydraulic movement and control of our customers' machines.

HYDRAULIC SYSTEMS

1. IDENTIFYING AND SELECTING HYDRAULIC CIRCUIT ELEMENTS
1.1. Definition of Hydraulics
Hydraulics, hydro from Greek, and aulos from pipe.
It is derived.
Today, transmission and control of forces and movements through “hydraulic” fluids
It is used to mean.
Hydraulics is the science that studies the mechanical properties of fluids.
1.1.1. Energy Types and Comparisons
1.1.2. General Information on Basic Physics Laws and Fluid Mechanics
• Flow: Passing through a specific flow section in a certain time in a hydraulic or pneumatic system
The amount of fluid is defined as the flow rate. Unit of flow is in liters / minute or cm³ / second
It indicated.

• Pressure: The fluid compressed in a certain cross section according to the Pascal principle, it is closed
Each unit on all walls of a container applies a force of the same value to the cross section and
called pressure. Its unit is the bar.
1 bar = 1 kg / cm²
o Effective Pressure: It is called the pressure value read on the manometer.
Absolute Pressure: Add an atmospheric pressure to the pressure value read on the manometer.
is the pressure value that occurs when it is installed.
• Paskal Law: If we neglect gravity, the force affecting a closed container
the resulting pressure affects each point of the vessel at the same intensity by the liquid.
F = P x A
F = Force (kgf)
P = Pressure (kgf / cm²)
A = Area (cm²)
• Continuity Equation: The flow rate of the fluid flowing through a pipe of different cross sections, the pipe
is the same value at every point. Considering that the flow remains constant, large
flows faster than sections.
Bernoulli Law: If we neglect the friction force,
The total energy it has is the same along the current line.
P1 x V 1 = P 2 x V 2
P = Pressure (kgf / cm²)
V = Speed ​​(m / s)
• Co-excitation (Abrasion): It is the removal of small pieces from the surfaces of metals. This
material destruction in the form, regional and sudden pressure and temperature
caused by changes.
• Hydrostatic Pressure: The height, density and weight (place of the liquid mass in a container
gravity) depending on the pressure applied to the bottom of the container. Depending on the shape of the container
It is not.
P = h.d.g
P: Pressure of the liquid on the bottom of the container (kg / cm²)
h: Liquid height (m)
d: Liquid density (kg / m³)
g: Gravitational acceleration (m / sec²)
1.2. Introduction of Hydraulic System
1.2.1. Basic Structure of Hydraulic System Logic and Rules of Operation
With the hydraulic pump driven by the electric motor, the fluid at a certain pressure and flow rate
It is the system where it is pressed and linear, circular and angular motion are produced with this hydraulic energy.
1.2.2. Advantages and Disadvantages of Hydraulic System
• Advantages of Hydraulic Systems
Hydraulic systems operate silently.
o Since hydraulic fluids are considered incompressible, vibration-free motion is achieved.
It is.
o High working pressures can be achieved.
Speed ​​can be adjusted while the movement is in progress.
Since hydraulic oil is used as a fluid, the circuit elements are also
They become oiled.
o The system operates safely with the help of safety valves.
Precise speed can be adjusted.
o Hydraulic fluid allows the heat generated to spread to the environment.
Hydraulic circuit elements have a long service life.
• Disadvantages of Hydraulic Systems
Hydraulic fluids are sensitive to high temperatures. 500C of fluid temperature
is not asked to pass.
o Hydraulic circuit elements will work at high pressures and their structures are strong.
should be.
o The prices of hydraulic circuit components are expensive.
o The connections of hydraulic circuit elements must be solid and leak proof.
o Since the hydraulic fluids have high friction resistance, they
unmovable.
o Storability is low.
o Flow rate is low. Circuit elements operate at low speeds.
Hydraulic fluids are sensitive to air. Air noise in the fluid and
causes vibration, regular speeds cannot be achieved.
1.3. Hydraulic Circuit Elements Structure and Operating Properties
1.3.1. Hydraulic Fluids and Their Properties
Hydraulic fluids are used to transmit hydraulic power. In addition, the hydraulic circuit
provides its elements to be lubricated and cooled. In the use of water as hydraulic fluid
problems such as corrosion, boiling point, freezing point and low viscosity are encountered. These problems
To eliminate some mixtures (such as oil, glycol) are added. Mineral oils, the most used
It is fluid. By adding additives, its durability and duration of use are increased.
• Viscosity: Refers to the flowability of fluids. Oil shows against flow
It is the difficulty. Flow resistance is high in thick oils and resistance to flow in thin oils is low.
Thick oils are small in fine oils with high viscosity.
Oxidation: The hydrocarbons in the composition of the hydraulic oil are chemically
oxidation to the occurrence of sludge or gum deposits by reacting
It called. The resulting mud causes corrosion on metal surfaces.
• Lubrication Ability: Appropriately selected oils form a film layer on metal surfaces.
by facilitating the movements of the working elements and reducing the friction resistance
It provides.
• Foaming: When the high pressure fluid moves at high speed in the system, the air
molecules and fat molecules colliding with shocks,
leads to foaming. To prevent this, sealing should be provided in the pipeline. Oil
manufacturers add anti-foaming additives to the oil.
• Pour Point: It is the temperature at which the oil loses its fluidity and starts to solidify.
• Flash Point: The flame temperature of standard oils is between 180ºC and 210ºC.
Since hydraulic systems do not exceed 50 ºC, no problems arise.
• Polymerization: Combination of more than one oil molecules of the same type without giving anymore and a new
is the formation of molecules. It is undesirable as it will change the properties of the oil.
H: Hydraulic oil
L: Effective agent that provides corrosion protection and / or aging resistance
P: Effective substance that increases or decreases loadability
1.3.2. Tank and Features
To the circuit elements that store the hydraulic fluid and prepare it in accordance with the working conditions,
(tank) is called. Bottom of the tank airflow for easy cooling of the heated hydraulic fluid
It should be designed to form. To prevent fluid returning to the tank from being absorbed without rest
resting plate should be placed. Tank capacity, the amount of fluid required for the hydraulic system and
It is selected according to the size of the distribution system. Practically it can be taken 3-5 times of the pump flow.

1.3.3. Hydraulic Pipe-Hose Equipment
In hydraulic systems, carrying the fluid from the tank to the receivers and from the receiver to the tank again
members are. Hoses are used in connecting hydraulic lines in moving hydraulic machines.
It has high flexibility. Piping; It is manufactured from seamless, high-pressure steel. In the future
more detailed information will be given.
1.3.4. Filters and Filtering Techniques
It is used to provide fluid cleaning to protect hydraulic elements from corrosion.
When changing the elements such as pollution pipe, hose; the introduction of new hydraulic fluid, or
may occur due to the failure of sealing elements. Permissible pollution in hydraulic elements
It indicates its value in the manufacturers' catalogs. It is in Micron (1 Micron = 0.001 mm). Pollution
value should be measured using the contamination indicator. The filter should be cleaned according to the values ​​taken from here and
those whose lifetime has expired should be replaced.
Filters are divided into three main groups:
• Suction line filters: Used to protect the pump in the suction line. Hydraulics from the tank
It cleans the fluid drawn in order to deliver it to the system and sends clean fluid to the system.
They are difficult to maintain because they are placed in the warehouse. When they are clogged, the suction of the pump becomes difficult. This
causes the pressure to drop. To prevent this situation, additionally
porous pump should be used.
• Return line filters: It filters the fluid returning to the tank from the hydraulic system after completing its task.
It is economical and easy to maintain. The disadvantage is that the cleaning of the fluid is
then it is done.
• Pressure line filter: Damage the circuit elements to the output of the hydraulic pump.
used to prevent. It is more sensitive to contamination.
The disadvantage is that the pressure-resistant body is faced with high pressure.
It is that it requires. Therefore, its construction is difficult and expensive.
1.3.5. pumps
It is the circuit element that sends the fluid in the tank to the system at the set pressure and flow rate.
Pumps convert mechanical energy into hydraulic energy. The pump does not
gets from the engine. Pumps do not create pressure. Pressure when the fluid encounters an obstacle in the system
It occurs.
While selecting the pump, it will be able to produce the flow and pressure that can perform the function of the system to be used.
should be chosen in size. The fluid and filter written in its catalog should be used. While the pump is running
The direction of rotation of the electric motor and the direction of rotation of the pump shaft must match. Pump
The protective oils in it must be cleaned. The pressure pipe must be bled when moving first,
the suction pipe must be filled with hydraulic oil. Also, the oil level should be checked frequently.

1.3.5.1. Manually Controlled Hydraulic Pump
Pump Types
A) Gear pumps
• External thread
• internal thread
• Piston hand pumps
B) Vane pumps
C) Piston pumps
• Axial piston
Inclined body
Inclined plate
• Radial piston
• Internal eccentric gear
1.3.6. Hydraulic Motors
To convert hydraulic energy of pressurized fluid into circular motion in hydraulic system
The elements used are called "hydraulic motors". High pressure fluids with hydraulic motors
using large torque moments. Producing big moments with a small volume
It is possible. Hydraulic motors; In construction machines where strong circular motion is required, the tool
etc on their countertops used in places. Stepless speed adjustment can be made with hydraulic motors. Movement
While continuing, the speed can be increased or decreased, the direction of rotation can be changed.
Engine types (hydromotor)
A) Gear motor
• External gear motor
• Internal gear motor
• Gear ring motor
B) Crawler engine
C) Piston engine
• Piston engine
• Radial piston engine
Axial piston engine
1.3.7. Hydraulic Cylinders
The circuit element that converts hydraulic energy into mechanical energy is called hydraulic cylinders.
Hydraulic cylinders are divided into two main groups:
• Single acting cylinders: The pressurized fluid enters from one direction of the cylinder and is applied to a single surface of the piston.
If it acts, this type of cylinder is called single acting cylinder. Its return can be spring and spring.
• Double-acting cylinders: Pressurized fluid enters from two different parts of the cylinder and acts on two surfaces of the piston.
They are cylinders that produce back and forth movements with fluid power.
1.3.8. General Classification of Valves
Determining the flow direction of the hydraulic fluid, the pressure and flow rate of the fluid are desired limits
It is the circuit element that keeps it inside. The following letters and positions are used with hydraulic valves:
P: Where the fluid from the pump is connected
R, S, T: Where the return line to the tank is connected
A, B, C: Where the pipes to the cylinder or the engine are connected
L: Where the leak line is connected.
X, Y, Z: Pilot line where fluid is used as a warning signal.
• Normally open: the front of the fluid P is open and the fluid from the valve without any external influence to the valve
These valves are called normally open valves if they pass to an element.
• Normally closed: the front of the fluid P is closed and the fluid valve is closed without any external influence to the valve.
If they cannot pass, such valves are called normally closed valves.
• Directional control valves: These are the valves that allow the fluid to go in the desired direction in the hydraulic system.
The control of the valves can be used electrically, mechanically, with pressure and manpower.
Directional valves are expressed according to the number of their positions as follows:
2/2 diverter valve
3/2 diverter valve
4/2 diverter valve
4/3 diverter valve
5/2 diverter valve
1.3.8.1. Pressure Control Valves

These are the valves used to control and adjust the pressure of the elements of the hydraulic system.
Types by Place of Use
• Safety valves: It is the circuit element that protects the hydraulic system against sudden pressure surges.
Normally closed valve is opened in case of pressure increase, opening excess fluid to the tank.
sends pressure down to its normal level.

• Pressure Reducing Valve: More than one desired to be operated with different pressure in the hydraulic system
In case of using cylinders and engines, the pressure reducing valve will operate with low pressure
It is connected to the input of the circuit element. It is normally open, it closes when the pressure rises.
The pressure drop rate is adjusted by the screw at the top.
• Pressure Sequence Valve: More than one cylinder or hydraulic element is activated in the hydraulic system.
the valve, which is normally closed, will operate at a different pressure.
value opens. The hydraulic fluid reaches other receivers.
• Flow Control Valves: The speed of the cylinder used in the hydraulic system, the number of revolutions of the engine.
are the valves used to adjust.
• On-Off Valves: Prevents hydraulic fluid from flowing in one direction, in the other direction
are the valves that allow it to flow.
1.4. Symbol Information of Hydraulic Circuit Elements,
Introduction of Symbols of Circuit Elements According to ISO 1219 Norm
1.4.1. General Symbols for Hydraulics and Pneumatics

1.4.2. Hydraulic Pumps and Motors
1.4.3. Hydraulic Cylinders
1.4.4. Pressure Control Valves in Hydraulics
1.4.5. Directional Control Valves in Hydraulics
1.4.6. Flow Control Valves
1.4.7. Warning (Control) Methods of Hydraulic Valves
2. MAKING HYDRAULIC CIRCUIT DESIGN
2.1. Hydraulic Circuit Drawing Information
2.1.1. Numbering of Elements in Hydraulic Circuit Drawings
Numbering of groups
Group 0: All elements of the energy supply unit
Group 1., 2., 3.,: One group number for each cylinder
Number system in order
.0: Work element such as 1.0, 2.0
.1: Final control element such as 1.1, 2.1
.4: All elements affecting the forward motion of the work element (even numbers) such as 1.2, 1.4, 2.2
.3; 5: All elements affecting the back movement of the work element (single numbers) such as 1.3, 1.5, 2.3
.01.02. : Elements between work element and end position element such as 1.01, 1.02
2.1.2. Function Block Diagram
It is used in control technique to show the flow of movements in relation to each other.
2.1.3. Hydraulic Circuit Drawing Rules
Energy supply unit at the bottom, energy control unit at the middle and drive unit at the top.
Diverter valves are drawn horizontally as much as possible. Transmission lines, linear and non-intersecting
It should be drawn. The initial positions of the elements should be shown. If there is more than one employee, each employee,
it should be treated as a separate chain of control.
2.2. Hydraulic Control Information
2.2.1. Location Based Control
It is the shape that shows the state of the machine that will do the work, the way of speaking An example location
The figure for the connected control is shown above.
2.2.2. Speed ​​Dependent Control