Essay: Hydraulic systems

In industries Hydraulic systems are taking over every work of high force movements like material handling and time is crucial to sustain the desired output and reducing losses utilized for operation. The current trends inside industry are towards implementing the utilization of flexible material handling, because it saves time, produce accurateness and it include flexibility. Flexible assembly with hydraulic system is key application in the field of designing, where in several software’s are available for the purpose of automation, as the process of feeding the material into conveyor requires necessary hydraulic cylinder for proper continuous process, it becomes quite difficult to do utilize the effect of hydraulic system on dusty and unhealthy situation as it requires proper control of the temperature with respect to manufacturer’s instructions on continuous hours of running leads to troubles of heating and various other losses related to heating, so reducing heating, cycle time etc is a main aim of this project. It deals with the design a separate integration of sub system using software for design. Except sub system design, no other option is available to do the cooling of main systems oil because of the availability of space, hence special type sub system is to be designed for this case, which can be used for cooling of hydraulic system, this will reduce operation time such that extend and retract time since degraded oil properties unable to achieve desired pressure, it increases productivity, and best quality of operation is possible. The most valuable function of a Sub system is to reduce temperature and other breakdown costs, because without maintaining the manufacturer’s instruction for the machine, operating a machine or process may lead to degradation; using a cooling system can eliminate the heating problem and its required pressure for the process. The project deals with the proposing a designing of diverse parts of Cooling cum filtration unit a mechanized system which is designed to cool and filter the oil of reservoir tank in order to maintain save oil properties for the continuous operation, 3- dimensional modeling by the utilize of creo software. Spannkraft Hydrosystem Pvt Ltd., Hingna Nagpur is one amongst the very few manufacturers of Hydraulic along with their components. The senior Managing of company is Mr. Ravi Kotangale. They have started their journey, by way of a small repair shop & today they are the leading manufacturer of hydraulic cylinders along with components and services barely by adhering the schedules received to them & the finest quality maintained right from the very first day. In addition to this, they have established their own manufacturing plant at Nagpur. Also for selling and servicing their range of hydraulic tools blossomed into very successful “onsite services”.
There are 1 CNC machines, 12 lathe,1 VMC machines,1 Honing machine,1 Surface Grinding machine, 3 milling machines at Spannkraft Hydrosystem Pvt Ltd. , Hingna Nagpur. Hydraulic power pack is the system which is utilizes to produce pressure force, fasten along with to support the cylinders for the extent of movements and assembly function. The mainly imperative criteria are designed for power packs are locating components together, positioning steadiness. A good quality power pack design is one which diminishes losses and inaccuracy. Pressure developing principle is defined within provisions of Pascal’s law that is extensively utilized for the technique used. Force study analysis is apprehensive with verifying whether applicable force through valve and components in system is adequate to sustain static position of equilibriumHydraulic power pack includes of the following elements:-
1.3.1. Hydraulic Motor
Hydraulic motor is an electric motor which provides power to the system. It runs with various standards under 1440rpm etc.
Hydraulic Pump
All hydraulic systems have one or more power-driven pumps Power-driven pumps are the primary source of energy and may be either, electric motor driven, engine driven or air driven. Pumps may be classified as either non positive displacement or positive displacement. The positive displacement type pumps are mostly used in hydraulic systems.
Hydraulic Cylinder
A cylinder is an actuating cylinder which provides motion and movements, it extend and retracts. The pressure builds up in the system to overcome the resistance and moves the piston of the actuating cylinder; fluid from the opposite end of the actuator returns to the selector valve and flows back to the reservoir. Operation of the system following actuation of the component depends on the type of selector valve being used. Then, the actuating mechanism reaches the end of its operating cycle, and the pump output continues until the system relief valve relieves the pressure. The relief valve unseats and allows the fluid to flow back to the reservoir.
1.3.4 Reservoir
A reservoir consists of working fluid oil. The tank has inlet port for return line and outlet port for delivery which is connected to pump for the supply to the system. Pump circulates the oil from reservoir. The reservoir is a tank in which an adequate supply of fluid for the system is stored. Fluid flows from the reservoir to the pump, where it is forced through the system and eventually returned to the reservoir. The reservoir not only supplies the operating needs of the system, but it also replenishes fluid lost through leakage. Furthermore, the reservoir serves as an overflow basin for excess fluid forced out of the system by thermal expansion (the increase of fluid volume caused by temperature changes), the accumulators, and by piston and rod displacement.
• Reservoir pressure relief valve—prevents over pressurisation of the reservoir. valve opens at a preset value.
• Sight glasses (low and overfull)—provides visual indication for flight crews and maintenance personnel that the reservoir needs to be serviced.
• Reservoir sample valve—used to draw a sample of hydraulic fluid for testing.
• Reservoir drain valve—used to drain the fluids out of the reservoir for maintenance operation.
• Reservoir temperature transducer—provides hydraulic fluid temperature.Diverse kind of Hydraulic Power packs are listed below:-
Table.1.1 Diverse Types Hydraulic Power packs
Sr. No. Types of Hydraulic Power packs
1 Industrial hydraulics.
2 Mobile hydraulics
3 Aircraft hydraulics
1.4 Importance of Power packs in Pressure operations
• Hydraulic unit is used preferably for huge systems, which are placed in, fabrication, plants power plants or huge machines and in which the hydraulic is intensively merged in the mechanical components.
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These includes biggest problem with using these hydraulic systems is their initial cost as they need so many accessories with the power supply. The actuators are also expensive although for most of the cases it would be much more expensive to get the same amount of power out of electric systems. In our case hydraulic power pack is working for material handling
• Heating of hydraulic fluid in operation is caused during system operation. By solving this heating problem the system is also lead to resolve the following problems related to this heating:-
– High oil consumption,
– Inefficient machinery operation,
– Environmental damage,
– Safety and accident liability,
– Hydraulic fluid contamination: The machine is located at dusty place since it handling the raw materials.
Problems occurring in existing Hydraulic power pack system are:
• Heating of oil due to continuous operation running.
• Cycle time is increased due to insufficient pressure development.
• Oil properties are degrading.
• Contamination of oil in the dusty environment.
• Unable to perform required operation with easiness.
• More oil is required for the operation such as refilling to maintain the oil level.
As solution to this problem greatly helps the industries to increase their productivity and reduce the time required for handling the raw material, this problem is needed to be solved to meet the current trends of designing, assembling and manufacturing. Solution to this problem requires assembly in modeling software’s which are now a day’s back bone of all design, assembly and manufacturing industries.
So this will help in updating our knowledge and to enhance the technical ability required in industries.[4]
1.6 Objectives and scope
The main objectives are:-
• To design and develop sub system for cooling of hydraulic power pack.
• To reduce corrective maintenance costs.
• To maintain the oil properties. The key function of critical literature survey observations is that it reviews conversation on essential point on the subject of Hydraulic system which is represented by different researcher.
2.1 Implementation of software
Tic.V has development of reservoir tank explanation to swirling and random instability of flow so to minimize this designing and using baffle plates analyzing through software such as CFD. Reducing the oil swirling phenomena by variety of designs in comparison to industrial tank simulation for the flow is carried out.
The focal point of the researcher paper is on software method and effectual model for the purpose of designing the reservoir tank creating, evaluating along with optimizing fluid flow designs intended for several complex-shaped 3-Dimensional components.[1]
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2.2 Necessities for Designing
Reddy in its paper described hydraulic unit can be a part of any system providing power movements and heating up is caused due to inefficiencies which lead input power to waste. Like the need of oil cooler it will act for the cooling function. Reservoir is simple rectangular box which dissipates the heat that has to be painted and corrosion resistant. Conversion of input into heat so to reduce heat generation the construction and design of tank has to be changed and modified for better operation. Also fins will help to escape and reduce the temperature rising.
The primary necessities that is important for hydraulic system designing for keeping the oil properties as per the manufacturer’s instruction manual. [2]
2.3 Energy saving
Recently energy saving has advanced in various fields due to the shortage of energy resources such as oil and in the hydraulic industry field oil is used widely, so there is need to protect the earth’s environment. Energy saving is also very important.
Use the oil and extracting its energy up to optimum level. We have to maintain the available oil. An approach on hydraulic pump unit is intermittent operation of the electric motor, called “idling stop type operation,” is attained by using the pressure holding function of the accumulator, to reduce the useless power and consumption. Inverter control is used for the pump. So the technique is applied for the pump only changing regulating the pump rotation speed and adjusting the flow rate only.[4]
2.4 Outlook for sub system
The sub system designing includes Oil degrading is a common problem both in lubrication and hydraulic systems. The main causes are thermal degradation (high temperature).
Consequences of the Oil Degrading:
Shorter oil life-
An increase in the level of oil degradation products act as a catalyst
A reduction of additive performance
Reduced oil performance-
Loss of lubricity
Valve failure
Restricted oil flow
Reduced productivity-
Monday morning problems: slow start-ups
Increased downtime
Reduced machine performance
Higher energy consumption-
Friction and wear
Increased maintenance costs-
Increased filter change frequency
Increased wear of components
Acidic corrosion in metallic components
Component failures
Cleaning of the oxidation deposits.
Environmental pollution consequences-
Greater disposal costs of oil and filter changes
Leakages.
So worked on this issue and suggested pioneering oil conditioning in the perspective of sub circulation designing. Properties of oil are analyzed by various tests. Considered on the basis of oil standards ASTM D341.
Sub system preparation is to envisage arrangement all the way through examining every offered components data concerning the available material and geometry of parts, operational equipments, and required activities.
The following yields are incorporated in the assembly of sub system preparation:
a) Point of reference
b) Position datum
g) Manufactured goods
h) Information and Design criterion.
A hydraulic circuit is a system comprising of an interconnected set of discrete components that works to transport liquid. Its purpose is to control where fluid flows as in a tubes network of coolant in a thermodynamic system and also to control fluid pressure (as in hydraulic amplifiers). For example, hydraulic machines uses hydraulic circuits (in which hydraulic fluid is pushed, under pressure, through a hydraulic pumps, various pipes, tubes, flexible hoses, hydraulic motors, hydraulic cylinders, and so on) to move heavy loads. The approach of describing a fluid system in terms of discrete components is similar to electrical circuit theory. Like as electric circuit theory works when elements are discrete and linear, hydraulic circuit theory works best when the elements (passive component such as pipes or transmission lines or active components such as power packs or pumps) are discrete and linear
The oil is taken from the main reservoir. The main reservoir is connected with ball valve (no.1) which is used for turning on or off the supply after it a hose pipe connection is provided for flexibility during maintenance (no.2) then temperature gauge (no.3) measures the temperature of oil from the main reservoir which id then sucked by a pump (no.3) which is coupled to the electric motor (no.6) then non return valve (no.7) it is spring loaded cone seat valve that is employed for assuring the one direction flow and in case of any choking (no.12) with maximum permissible contamination of NAS1638. A high level of safety is achieved by shut off valve (no.9) consists of a knob for controlling the flow rate of oil in the system, then it leads to the heat exchanger (no.8) it is integrated with the water supply by stainless steel pipe with the suction strainer (no.14) for clear water to prevent clogging of water supply in heat exchanger, the water is also checked by a temperature gauge (no.2) for its on and off water line ball valve (no.13) is incorporated. Now the reduced temperature is checked and passed to the filter (no.11) which is facilitate with clogging indicator (no.18). After the oil is cooled and filtered it again return to the main reservoir for performing continuous operation. The (no.17) is the BSP port provision for interconnecting any devices in future advancement.
3.3 Parameters needed in cooling system preparation
The parameter needed for fixtures preparation contains following points.
1. Firmness
The parts should be supposed to be tough enough to under arrest the noise and vibration.
2. Secure
Sub system should be in suitable place and must be safe.
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3. Clearance
Sufficient amount of clearance should be provided around the sub system so that operator’s can easily reach the parts for observation and maintenance.
4. Flexibility
While maintenance of any of the system hose pipe connection provision is incorporated in between them so that there will be no unnecessary rigidity.
5. Supply
For avoiding any clogging and interruption in the system the water supply lines is stainless steel also installed with stainless strainer.
6. Ease in design
Design of the structure ought to be a uncomplicated one. Because complex shape requires more maintenance.
7. Rigidity and stability
It should remain perfectly rigid to the ground and stable during operation. Provision should be made for proper positioning and rigidly holding parts.
8. Viscosity
The viscosity of industrial lubricants or hydraulic fluids, is measured by kinematic viscosity v [m2/s], which is formulated by dividing absolute viscosity by density. It is expressed in units of square millimeters per second (mm2/s). For viscosity measurement, a capillary viscometer is used to determine kinematic viscosity (mm2/s) as per JIS K 2283 “Crude petroleum and petroleum products – Determination of kinematic viscosity”. Hydraulic fluid viscosity directly affects the performance of hydraulic systems. System operation for a hydraulic fluid viscosity different from the specified range may result in internal leakage, suction failure, poor lubrication, valve malfunction, or heat generation in the circuit and shortening the life of equipment or may causing a major accident which is a big loss.Hydraulic drive systems works is the basis of Pascal’s law. As the pressure in the system is the remains same, the force by fluid gives to the surroundings so it is therefore equal to pressure × area. In this, a small piston feels a small force and a large piston will feels a large force.
The same principle applies for a hydraulic pump with a small swept volume that asks for a small torque, combined with a hydraulic motor with a large swept volume that gives a large torque. In such a way a transmission with a certain ratio can be built.
Most hydraulic drive system uses hydraulic cylinders. Here the same principle is used — a small torque is transmitted into a large force
A hydraulic drive system is a drive or transmission system that uses pressurized hydraulic fluid to power hydraulic machinery work. The term hydrostatic refers to the not from the kinetic energy of the flow but transfer of energy from flow and pressure.
A hydraulic drive system consists of three parts: The generator (e.g. a hydraulic pump), driven by an electric motor, a combustion engine; valves, filters, piping to guide and control the system and the actuator a hydraulic motor or hydraulic cylinder to drive the machinery.[2]
3.6 Selection of components
The part which is assembled within the assembly is of standard material based on Indian standards. This is sub system called cooling unit manufactured by company. It maintains the oil temperature range. As hydraulic system is mechanical regular and symmetric. We can check 3D drafting of this part designed in Creo 2.0 below. There are abundance of oil conditioning systems available which can be put into practice in a hydraulic system. Correct methodology should be utilized while choosing material handling systems hydraulic power pack. As per the literature survey done the achievable solution is cooling unit as a sub system.
Features of cooling unit
• All body is made up of mild steel material.
• Seam less pipes are used in order to reduce friction and leakages.
• The model prevents breakdown of operating system.
3.6.1 Working
The main system is hydraulic power pack which consists of a oil reservoir and that oils temperature is in increased condition so that oil is drawn into the sub system and the oil is drawn from the main systems reservoir through a pump then it transferred to cooling heat exchanger and filtering component and is circulated across various gauges like temperature and pressure. The input is high temperature of oil and output will be reduced temperature of oil which again returns to the main system for performing the material handling. The main system works on the Pascals law that is directly related to the quality of oil properties so to maintain that oil properties our sub system or cooling unit is working.
3.6.2 Selection of Filter
There are many types of filters available, but for this work the required filter is different. In this project work the process is continuous. For this first step is oil is cooled in heat exchanger, then filter acts. Almost every hydraulic system uses a return line filter. It’s designed to mount directly onto the tank cover. Therefore, you can easily replace filter element(s) when needed; it’s perfect for easy maintenance. Selected return line filter based on the maximum flow of the hydraulic system.
Characteristics of an in line filter:
• Low cost
• Very easy servicing
Features of Hydraulic Filter
Grade of filtration: Fine Filtration
o 40 to 90 μm, using stainless steel filter mesh
o 10 μm, using filter paper
o 10 to 25 μm, using glass fibre
Note: A general rule, the distance between the bottom of the tank and the end of the pipeline should be more than 2 to 3 times the pipe diameter, to prevent the hydraulic oil from foaming in the tank while in all operating conditions so the return flow must come from below the fluid level in the tank. Indication is made by colour codes on dial which shows Description – 0-20 psi green, 20-24 psi yellow, 25-60 psi red, glycerin-filled
Plate type heat exchangers (PHE) consist of a number of parallel flow channels, formed by adjacent metal plates that are either separated by gasket or welded material around the perimeter of each plate. The plates generally are made of stainless steel, can be formed from a variety of metals. Figure shows 1.Carrying bar 2.Connections 3.Fixed frame 4.Tightening bolt 5.End plate with 4 holes 6.Channel plates with 4 holes 7.End plate with all 4 ports blind 8.Pressure plate.Power packs are utilized for power requirements. To maintain the life of oil circulated from various units such that heat exchanger and filtering components.
For creation of conditioning unit following steps are involved:
Symbolic line diagram for cooling system.
2. Three dimensional Modeling in CREO 2.0.
Assembly of different components required.
4. Model Fabrication.
5. Installing and Testing
4.1.1 Existing reservoir
The existing reservoir consists of oil which is used for development of pressure to hydraulic cylinder is shown in fig 4.1. In this the oil is circulated in continuous operation. So the oil is heating and loosing the viscosity therefore to avoid this heating problem there is necessity to develop new design to improve the productivity and increase the life span of oil.
Fundamentals confers the essential tasks in utilization of Creo 2.0, are such as association, organization of data, functioning with user interface, functioning by means of the model, and so on. Utilize basics help at the point in time you initial start learning how to make use of Creo 2.0 software or when you desire to improve your knowledge. Fundamentals help initiate you to the necessary terminology, tasks, and method so you can be capable to construct your models proficiently and share information, thoughts, and procedure in real time. You will become skilled at how to utilize management of data tools, modify the user interface, work with your model, and supervise model composition. From a conceptual sketch you can create a part in part modeling .you can also build up a part through solid element based modeling. Base is the essential structure which provides support to the components. All the components like filter, motor, pump etc. will rest or mounted on this base frame. It is the pipe lines are designed using a seamless pipe of diameter 42mm on the basis of standards this tubes circulates the fluid to components for performing various types of operation. Motor supplies power to the pump. It is connected using flexible coupling with a bell housing. It is foot face mounted with shaft dia 38mm and its dimension are 470L,265W,340H 61 Kg weight efficiency=87%. Filter operates with a range of 10microns. It increases the life span of oil with safety also. CAD modeling is utilized in diverse ways by various people in engineering practice. Some utilized it to create drawing and design of document. Other may utilized it as a visual tool by featuring animated displays. This CAD software offer us with different tools required. All components are joined together with the constraints considering true directions. In design of sub system the components included that firstly we consider or discussed material of the body and after that carried out analytical design of parts such as valves for flow control, stand for clamping the filter. Selecting the accurate material for utilization is significant intended for sturdiness and permanence of components. The materials that is utilized should be appropriate for toughness and for repetitive use. One of the key considerations is damping. Functioning with a fixing results into vibration which are caused by sound, mechanical oscillations. Damping decrease vibrations by dissipating it. Pig iron is melted to get grey cast iron. It is an alloy made up of carbon and iron. Little quantity of Phosphorus element, silicon element, Sulphur and manganese are also present there in it. The cause behind its popularity are capability to compose compound structures and low cost. In addition, the admirable property of Grey Cast Iron has made it one of the mainly extensively used alloys. So for the reason the material used for making the base is mild steel. [1]
The supporting parts is mostly utilized for enlivening and lowering the mass slowly which is required in any assembly shop of heavy industry. It mainly includes a screw and bronze nut. In order to maximize service life with heavy load condition the material used are mild steel.
• Power = (P x Q) ÷ 600
where power is in kilowatts [kW], P is the pressure in bars, and Q is the flow in litres per minute.
Power= (100×30)/600=5kW
• Calculating the power input to the pump, the total pump efficiency ηtotal must be included, Power input = Power output ÷ ηtotal. Power input=5/.87 =>5.5kW
• average for hydraulic pumps, ηtotal = 0.87
• Torque= (IPx60000)/2piN=36Nm
• Hydraulic motor output = (2piNT)/60000=5.5Kw
• Flow @1450rpm (from manual)
LPM=70 Mininmum and 120 maximum
Port connection=2inch Flange=2.75inch
• Kinematic viscosity
If any randomness like the pressure fluctuation, pipe connection type, pipe vibration, and considering other factor. Refer to the nominal pressure values and their corresponding safety factors in the left table for pipe selection.
2. “Sch. No.” is an abbreviation for schedule number. Note that “★”
indicates special thick wall steel pipes with no schedule number. <Reference>
JIS G 3452, 3454 to 64
Description, Schedule number = 10 × P/S
Where P: Operating pressure MPa S: Allowable stress MPa
From the above table taking it reference for the hydraulic components selection on the basis of international JIS 3455 standard. Therefore 32mm diameter pipes are used considering the safety limits that can withstand up to 250°C and pressure 600bar
For calculating viscosity index of the fluid, The kinematic viscosities of the fluids at both temperatures has been measured in lab by using Ubbelohde viscometer it is used, and in most of the test methods like ISO 3104, ISO 3105, ASTM D 445, ASTM D 446. System is installed and run the test for temperature of oil is reduced to 80oC to 40oC in 15min and viscosity of oil is 68CST. So our system can work continuously for the conditioning of oil. • The user will be able to reduce the cost of refilling or changing the oil.
• The user has no longer to monitor or estimate when the filter will be clogged it is easily visible signal.
• The properties of oil will be under controlled conditions.
• The time required for feeding the raw material via cylinder is optimized. • By solving this heating problem the system is also lead to resolve the following problems related to this heating:-high oil consumption, inefficient machinery operation, environmental damage, safety and accident liability.
• Hydraulic fluid filtration since the machine is located at dusty place since it handling the raw materials.
• Life span of oil is increased.
• The implementation of newly designed sub system results in increased productivity after the payback period.
• The newly designed sub system also reduces the costs of maintenance required for process.
• All the values of deformation and stresses by engineering data is comparatively lower than standard values and hence, we can conclude that design is safe. Some of the recommendations for future research are
• Modifying the model for advancement by employing sensors and also utilizing provision of BSP.
• Instead of manual system it can be integrated with PLC control for better display of data.
• Modification can be done on filter component by buzzer or light indicator system in case of clogging for safety.
• Development of combined system for power pack as well as oil conditioning in a single structure to minimize the extra costs and space