Automatic Lubrication System



CHAPTER 1
INTRODUCTION


            Now-a-days automobile vehicle have become the best source of transportation. Transportation in the sense of transporting people, goods etc....from one place to another. In this automobile vehicle, there are hundreds of moving parts.
Generally in all the automotive vehicles, lubrication of all parts is the major and important problem. Mainly most of chassis parts are only greased. This is done manually at all the service station and maintenance shop. This increases the cost of lubrication, since the person should be employed for doing this work. The main aim of our project is to automate the work of lubrication.
            A separate unit has been designed for lubricating most of the parts. The main requirement of automatic lubrication is compressed air. This is supplied by the compressor, already available in most of the vehicles. The unit mainly consists of single acting cylinder, piston with spring, timer, solenoid valve and container or lubricating tank.
The only manual work required is to fill the lubricant in the container. By fixing this unit, there is a considerable reduction in cost of lubrication, further all the parts are lubricated. There is no chance of leaving a part without lubrication, which may happen in the case of manual lubrication.
            In these automobile vehicles, there are hundreds of moving parts. When one part move over another, due to friction heat is created. Thus heat tends to change the characteristic shape or size of the components. Hence they fall to perform.
Application of lubricant between the moving parts avoids the intimate contact of two surfaces thus reducing the heat and wear and increasing life of the component. Hence for a trouble free and silent operation of an automobile, lubrication is an essential one.
Supplying the lubricant between the moving parts is simply termed as lubrication. Lubrication must be done properly and at right time. Inadequate lubrication will cause serious troubles.
Lubrication of a motor vehicle may be classified under two systems.
1. Engine lubrication system
2. Chassis lubrication system
            Our project is focused to the lubrication of chassis. All the lubricating points should be lubricated periodically for the trouble free operation of the vehicle.
            The lubricant normally used for the chassis lubrication is semi-solid lubricant grease. Grease is a suspension of metallic soap dispersed in lubricating oil. This is done manually in the maintenance shops.
            Applying grease manually to all the parts is a difficult task. In our subject "AUTOMATIC LUBRICATION SYSTEM" we make the job of lubricating the chassis automatic. Further applying the grease manually is possible only when the vehicle is stationary and by a known person. By making the process of lubrication automatic all the parts are lubricated even when the vehicle is in motion and no known person is led for lubrication, which makes the task easy.












CHAPTER 2
LITERATURE REVIEW
           
Lubrication is probably the most important phase in motor vehicle maintenance. Inadequate and improper lubrication may ruin various parts of the vehicle. As the lack of chassis lubrication system, failure will come in the longer run to extent of more gravity.

2.1 LUBRICATION SYSTEM

Lubrication is probably the most important phase motor
        Vehicle maintenance. Improper lubrication may run in various parts of vehicle.  To avoid that we are going for this system.
             Automobile lubrication classified into
·         Engine lubrication system
·         Chassis lubrication system

2.2 FUNCTIONS OF LUBRICATION SYSTEM

                        The functions of lubrication are to decrease friction by preventing direct contact of rubbing surfaces. The force of friction which retards the motion of one body in contact with another is divided into two types.

·         Sliding friction
·         Rolling friction




2.3 OBJECTIVES OF LUBRICATION

·         To reduce friction between the moving parts
·         To reduce wear of the moving parts
·         To act as a cooling medium to remove heat
·         To form good seal between piston rings and cylinder walls
·         To prevent deposition of carbon, soot and lacquer
·         To resist oxidation this causes sludge and lacquers

2.4 PROPERTIES OF THE LUBRICATING OIL

As is clear from the above discussion the lubricant must have certain basic properties to meet the requirements of the lubricating system. The follow­ing is a brief discussion of the-properties which are important for engine operation.
1.       Viscosity. Viscosity of an oil is measure of its resistance to flow and is usually measured in terms of Saybolt Universal Seconds (SUS) which is the time required, in seconds, for a given quantity of the oil to flow through a capillary tube under specified test conditions. Viscosity is usually expressed at two temperatures - 18°C (0°F) and 99°C (210T). Viscosity is also expressed in centistokes, centipoise and Redwood seconds. The basic difference between all these systems of expressing viscosity lies in the type of apparatus, called viscometer, used for its determination. Centistoke is a unit of kinematic viscosity while centipoise is a unit for absolute viscosity as determined by a Cold Cranking Simulator
2.       Viscosity Index. The viscosity of an oil is substantially affected by its temperature, higher the temperature lower is the viscosity. This variation of viscosity of an oil with changes in temperature is measured by its Viscosity Index (V.I.) The oil is compared with two reference oils having same viscosity at 99°C '(210°F). One, a paraffinic base oil (considerable change in viscosity with temperature), is arbitrarily assigned an index of zero and the other, a naphthenic base oil (little change in viscosity with temperature), is assigned an index of 100:
A high viscosity index number indicates relatively smaller changes in viscosity of the oil with temperature. Viscosity index of an oil is very impor­tant where extreme temperatures are encountered. The lubricating oil must maintain a sufficient viscosity at high temperatures and still should not be too viscous for starting the engine at low temperatures. Typical examples of extreme temperature conditions are the hydraulic system in an aircraft and automobile engine in cold weather.
            To improve the viscosity index of oil certain compounds, called V.I. improvers, are added to it. These are viscous, long chain paraffinic, com­pounds which en
able to obtain oil having easy starting characteristic of thin oils combined with good protection against high temperature.
            For automobile applications oils having a viscosity index above 90 are considered to be of high V.I., oils between 55 and 90 medium V.I., and below 55, low V.I.
3.       Cloud Point and Pour Point. If oil is cooled, it will start soli­difying at some temperature. This temperature is called cloud point. This clouding or haziness of the oil interferes with its flow. The, pour point is that temperature just above which the oil sample will not flow under certain prescribed conditions. This temperature is largely determined by the wax content of the oil since as the temperature is reduced was crystallizes out in long needle-shaped crystals, forming honeycomb with oil held in the voids between the crystals. Generally oil derived from paraffinic crudes tend to have higher pour points than those derived from naphthenic crudes. The pour point can, however, be lowered by the addition of a pour point depressant usually a polymerized phenol or ester. These substances function by depositing insulating films on the wax crystals as they begin to separate out from the oil and by reducing the size of crystals.

This characteristic of the oil is very important at low temperature operation since it will affect the flow in the pressure line of the lubricating system. Pour point must be at least 15°F lower than the operating tempe­rature to ensure maximum circulation. Even at this temperature the oil may be quite viscous so that high power may be necessary for starting.

4.       Flash Point. The temperature at which the vapours of oil flash when subject to a naked flame is known as the, flash point of the oil. If the container is closed at the time of the test it is called closed flash point, and if open it is called Open flash point. Fire point is the temperature at which the oil, if once lit with flame, will burn steadily at least for 5 seconds. This is usually 11°C higher than open flash point and varies from 190°C to 290°C for the lubricants used for the internal combustion engines.

            Fire and flash points are good indication of relative flammability of the oil and except for the safety from fire hazards; they do not have any significance for engine operation. However, fire and flash points of used lube oil are very good indication of the crankcase dilution. The light ends of the fuel, which leak into the crankcase, readily evaporate and burn at considerably lower temperature than the temperature at which the oil would have burned, clearly indicating the degree of dilution.

5. Specific Gravity. The specific gravity of the engine lube oils varies between 0.85 to 0.96. Naphthenic base oils have higher specific gravity than the paraffin base oils. This property is of little importance except as an indicator of weight and volume.

2.5  FUNCTIONS OF THE LUBRICATING SYSTEM
1.     Lubrication.
The main function of the lubricating system is to keep the moving parts sliding freely past each other and, thus, reduce the engine friction and wear.
2.     Cooling.
To keep the surfaces cool by taking away a part of their heat through the oil passing over them. This cooling action usually takes place simultaneous to the lubricating function. However, under certain conditions lubrication system is used to keep certain engine parts cool which due to their typical location do not come in direct contact/with the cooling water. One typical example is the oil cooling of pistons of high specific output engines.
While performing its cooling function the lubricant is exposed to heat­ing and agitation which promote oxidation. This requires oil to possess good oxidation stability. The heat input to the oil increases if the cooling function is extended to piston cooling. For a naturally aspirated diesel engine the heat input to the oil can be equal to some 6-8% of engine power output. This value is further increased by 50% for an indirect injection engine and doubled for turbocharged engines.
3.  Cleaning.
To keep the bearings and piston rings clean of the pro­ducts of wear and the products of combustion, especially the carbon, by washing them away and then, not allowing them to agglomerate to form sludge.
4. Sealing.
The lubricating oil must form a good seal between piston rings and cylinder walls. The oil should be physically capable of filling the minute leakage paths and surface irregularities of the mechanical sealing elements, i.e., cylinders, pistons and piston rings. The oil as a sealant is subjected to high temperatures and hence must possess adequate viscosity stability.
5. Reduction of noise.  
Lubrication reduces the noise of the engine. These functions are conflicting functions. The oil cools best when it is thin but seals best when it is thick. The oil must collect dirt to scavenge and clean, but to lubricate it must be clean. The engine produces not only power but a number of oil contaminants also. The oil should be able to absorb these contaminants without affecting its main functions.
Increased speed, compression ratio and, hence, increased power output all result in higher pressures and temperatures. The shock loading of bearings is also severe. Larger valves require stiffer valve springs which, in turn, result in increased stresses and elevated temperatures for many related parts.
All these conflicting and difficult to meet requirements require skilful juggling at the hands of the engine designer.

2.6 TYPE OF LUBRICANTS
The lubricants are of three types:
1.     SOLID LUBRICANTS
         Graphite, mica, soap stone or steatites are some examples of solid lubricants. It is also used as a cylinder lubricant both in powder and colloidal form. It has co-efficient of friction and is stable at high temperatures.
2.        SEMI-SOLID LUBRICANTS
          The only semi solid lubricant is grease. Semi solid lubricants are in chassis lubrication. It is widely used in automobiles at places where high temperatures are encountered like in axles. Grease of metallic soap dispersed in a lubricating oil other ingredients are also added in it to provide the required structural ability and resistance to deterioration in service. Greases are given penetration fluid and usually embodies a lime, lithium or aluminium base, which gives it good spreading qualities, load carrying ability and resistance to water.
            Generally for lubricating the chassis, the vehicle should be stopped, and with the help of grease gun grease is applied to all the lubricating points. In this case there are chances for a part being left with oil lubricating or reduce the life of that part. The project work undertaken mainly focuses on lubricating all the chassis points simultaneously. The lubricating points are connected through permanent tubes from the main unit. Their by fixing each part and more over we are left trouble free.
3.  LIQUID LUBRICANTS
          Mineral oil, vegetable oil, animals oil are some of the example of the liquid lubricant. Liquid lubricants are used in the automobile engine lubricating system such as transmission and rear axle systems.




2.7  SAE Numbers
The lubricating oils are usually marketed by their SAE Viscosity numbers, recommended by the Society of Automatic Engineers. The Viscosity number is determined by the range of viscosities within which it falls at the given temperature, as shown in below table. The reference temperatures are 00 F(-180C) and 2100F(990C).

SAE Number
Viscosity at -180C
(Saybolt second)
Viscosity at 990C
(Saybolt second)
5W
4000[800CP]
_
10W
12000[2400CP]

20W
48000[9600CP]

20

45 to 58[5.7 to 2.6 CS]
30

58 to 70[9.6 to 12.6 CS]
40

70 to 85[12.9 to 16.8 CS]
50

85 to 110[16.8 to 22.7 CS]
            CP= centipoises                      CS= centistokes

                                    Table: 2.7.1: SAE Lubricating Oil Viscosity Grade Limits






2.8  PNEUMATICS
          Pneumatics is employed in a variety of settings. In dentistry applications, pneumatic drills are lighter, faster and simpler than an electric drill of the same power rating (because the prime mover, the compressor, is separate from the drill and pumped air is capable of rotating the drill bit at extremely high rpm). Pneumatic transfer systems are employed in many industries to move powders and pellets.
          Pneumatics devices are also used where electric motors cannot be used for safety reasons, such as mining applications where rock drills are powered by air motors to preclude the need for electric motors deep in the mine where explosive gases may be present. Pneumatic logic is a reliable and functional control method for industrial processes. In recent years these systems have largely been replaced by electrical control systems, due to the size of the logic units and cost versus their counterparts.  

2.9 CLOSURE
From the literature reviewed so far, it is clear that the auto lubrication system of tomorrow is very essential because of its certain specific features. Hence an attempt has been made to design such a system. The details of the work carried out are presented in the succeeding pages.





                                                CHAPTER 3
                             FABRICATION OF THE EQUIPMENT
          The air compressor is connected to the inlet solenoid valve with the help of tube. The tube is made up of rubber material. The outlet of the solenoid is connected to the inlet of the piston with the help of the same type of tubes. The piston units of two outlet valves in which one is connected to the distributor and other is connected to the lubricating tank. Both the outlet valves are non return valves is which they supply air in only one way.
            The other end of the solenoid valve is connected to the timer and the timer is connected to the lead acid battery. The capacity of the battery is 12v. The timer is controlled with the help of the battery. The controls the solenoid valve so that the compressed air us also controlled by the same timer. The timer can be fixed to any specified interval of time for the self lubrication purpose. There is also retaining spring in the piston which compresses the lubricant and also compresses the air.









CHAPTER 4
DESCRIPTION OF THE EQUIPMENT
AUTUAL PROBLEM ATTEMPTED:
                          As concluded earlier, because of many inherent advantage of AUTO LUBRICATION SYSTEM, when compared with conventional manual lubrication, an attempt has been made to test the ability of AUTO LUBRICATION SYSTEM.
                        The proposed auto lubrication system can be tested only on the actual automotive chassis. Since the chassis is not available here, the systems   mounted over a test bench and tested.
                        It is designed to satisfy the following requirements:
                        1) To lubricate all the chassis parts uniformly and at regular intervals.    
                        2) To prevent the failure of lubricating of parts that  may happen in
                            manual lubrication.
                       3) To reduce the cost of lubrication.
                       4) To eliminate the wastage of lubricant.








4.1 SCHEMATIC DIAGRAM


Fig: 4.1: Schematic diagram of Automatic Lubrication System


Hence to perform the above task, the parts, listed below are essential.
1.   Single acting Cylinder
2.   Piston
3.  Lubrication tank
4.   Outlet adopter
5.   Coil Springs
6.   Tubes
7.   Non return valve
8.   Solenoid valve
9.   Timer
10.  Connectors
4.2 MATERIAL SELECTION
SI. NO.
NAME OF THE COMPONENT
MATERIAL
1.
Single acting cylinder
Mild steel
2.
Digital timer
Plastic
3.
Solenoid valve
Alloy
4.
Non return valve
Alloy

Table: 4.1: Material selection


4.3 DESCRIPTION OF COMPONENTS
1. SINGLE ACTING CYLINDER
            The force exerted by the compressed air moves the piston into directions in a double acting cylinder. The single acting cylinder produces less force during retraction, because the piston rods cross-sectional areas are subtracted from the piston area under pressure.
             They are used particularly when the piston is required to perform work not only on advance movement but also on the return movement. In principle, the stroke length is unlimited, although buckling and bending must be considered before we select a particular size of piston diameter, rod length and stroke length. This is a square block made of mild steel and act as cylinder for this unit. It has a hole on one side through which the air from compressor comes inside. There is a  hole on the other side of the block and is connected to the outlet and to the non-return valve,, through which the oil comes out.

Ø  Max Pressure               - 12bar
Ø  Outer Diameter           - 48mm
Ø  Inner Diameter            - 40mm
Ø  Inlet & outlet diameter - 8mm

The force exerted by a single acting pneumatic cylinder can be expressed as
         F = p A
             = p π d2/4        
Where,
                        F = force exerted (N)
                        p = gauge pressure (N/m2, Pa)
                        A = full bore area (m2)
                        d = full bore piston diameter (m)


2. PISTON
        Piston is used to push the oil to all the points through the tubes. It reciprocates inside the bore of the cylinder block. The material is rubber. One side of the piston has a large coil spring. This is used for the quick return motion of piston.
3. LUBRICATION TANK                      
        The lubricant oil is filled in this container. It is made of plastic and has flat bottom. An adopter is fixed at the bottom of the tank with which it is fixed to the cylinder block.
4. OUTLET ADOPTER
        The outlet adopter is fixed to end side of the cylinder block. This has a reduced diameter compared to that in the cylinder; so that it increases the outlet velocity of the lubricant inside the cylinder.
5. COIL SPRINGS
       A single coil springs is used in the unit apart from those used in the cylinder assembly. The larger diameter spring is placed inside the cylinder. This is used to give a quick returning motion to the piston.

Ø  Type                      - open coil helical spring
Ø  Material used        - steel.
Ø  Length                   - 120mm
Ø  Mean diameter      -14.5mm
Ø  Wire diameter       - 2.0mm.
Ø  No. of coils           - 12.


6. TUBES
       Tubes carry the lubricant from the main unit to all the lubricating point in the chassis.
7. NON RETURN VALVE
       Non return valve has a small ball with the small diameter coil spring which is in the outlet adopter. There are two non return valves one is in the outlet of the single acting cylinder and another is in below the lubricating tank connected to the cylinder.
8. SOLENOID VALVE
      This operates by receiving the signal from the timer and allows the compressed air to pass to the cylinder when the signal from the timer is cut-off. The air in the cylinder goes to the solenoid valve due to spring tension and escapes through the top of the solenoid switch.
     A solenoid valve is an electrical valve for use with liquid or gas controlled by running or stopping an electrical current through a solenoid, which is a coil of wire, thus changing the state of the valve. The operation of a solenoid valve is similar to that of a light switch, but typically controls the flow of electricity. Solenoid valves may have two or more ports. In the case of a two-port valve the flow is switched on or off, and in case of a three-port valve, the outflow is switched between the two outlet ports.

Ø  Maximum pressure : 20bar
Ø  Power supply          : 220v AC
Ø  Size                          : 1/4” 3/2”
Ø  Current                    : 100mA



9. TIMER
       This gives an electrical signal to the solenoid switch at present time interval. This time could be changed according to our requirement. It is like a spring type watch, and the time interval of electric signals to solenoid is controlled by the timer. Once it is pre-load, it operates continuously.

Ø  Power supply      – 230v, AC
Ø  Type                    – Delay timer
            Model                  – Cyclic

10. CONNECTOR    
         Connector is used to connect the cylinder to the solenoid valve, compressor and oil tank.
















CHAPTER 5

WORKING PRINCIPLE

Automatic lubrication using timer circuit consists of single-acting cylinder, electronic timer, solenoid valve, non-return valve, distributor, and oil tank and pipe lines. All the parts are connected as shown in the diagram. Then the whole set-up is connected to compressor. Then we have to start the compressor and open the pipe line to the system. The compressed air will be controlled by the solenoid valve. After that we have to connect the timer in the power unit and ON the switch. Now the system is ready to work.
When the timer is ON, in the given seconds it start to control the solenoid valve. First it will open the valve, and in that time the compressed air is passed through the valve and reaches the cylinder.
Then the compressed air will push the piston inside the cylinder against the spring tension. It will also push the oil to outside of the cylinder. In that time the non-return valve connects to the outline is open and oil is coming out of the cylinder with high force. In the return stroke the timer will cut the power to the solenoid valve. Then the flow of compressed air is cut to the cylinder. In that time the piston will move to the left dead center with the help of spring tension.
While the piston move towards the left, the non-return valve in the outline is closed and the non return valve connected to the oil tank is open and oil will come in the line and get in to the cylinder. The cycle repeats the same for required time.






CHAPTER 6
APPLICATIONS
·         All springs and shackles.
·         Steering linkages. (tie-rod, drag link rod etc.,)
·         All “S” cam shafts.
·         Clutch with-drawl bearing.
·         Engine water pump.
·         Clutch linkage.
·         Accelerator linkages.

ADVANTAGES
·         All points lubricated simultaneously.
·         Uniform flow of lubricant to all points.
·         Timer is  used to lubricate points at regular intervals.
·         Wastage of lubricant is eliminated.
·         Grease nipples are replaced by small adopters.
·         Wear and tear of the lubricating components due to improper maintenance is eliminated.
·         Requirement of man power for this system is not necessary.
·         As the wastage of lubricant is avoided, the lubrication cost is less.
·         Equipment such as hydraulic lift, gear pump etc., used in ordinary lubrication is completely eliminated.
·         The components can be lubricated even when the vehicles is in operation.

DISADVANTAGES
The universal joints and its bearings cannot be lubricated since they are rotating.

CHAPTER 7
COST ESTIMATION

SI NO.
NAME OF THE COMPONENT
QUANTITY
AMOUNT IN RUPEES
1
Single acting cylinder
01
1000
2
Electronic timer
01
175
3
Solenoid valve
01
340
4
Non-return valve
02
230
5
Oil tank
01
30
6.
Connector
04
64
7
Lubrication oil
1 litre.
125

                                                                                                Total    : 1964
                                                         Table: 7.1: Cost Estimation
           
When we are producing the above mentioned lubricating system in large scale, the cost of production can be considerably reduced. And hence, the above mentioned system is highly economical.









CHAPTER 8
CONCLUSION


The conclusions drawn by completing this project are by fixing this equipment on the material handling equipments like cranes, hoists. There is considerable reduction in the lubrication cost, and the life of the moving parts will be increased since they are lubricated periodically with precise timing. Also the manual fatigue in lubrication is almost eliminated.










































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