Fluid power system design laboratory reportName :- ID NO :- GSE/0918/07Lab Report1. Objective of the laboratorya. Main objective :- the main objective of this lab is to see and acquaint students what they Know in the theoretical part with the existing practical applications using the different components of the fluid power system. B.Specfic Objective To be familiar with components of fluid power system. To measure the time elapsed during extension and retraction of the double acting cylinder. To measure the pressure reading during extension and retraction of the double acting cylinder. Identify and observe different hydraulic circuit symbols with their actual parts.2. TheoryThe hydraulic trainer allows assembling a range of hydraulic components using the self locking hoses joints and connecting the various components fitted on the test bench. For an easy use of all components are equipped with the quick-acting and self locking devices. These includes Prime mover :- delivers input energy to a pump of hydraulic system. Hydraulic pump :- converts mechanical energy into hydraulic energy. Pressure Gauge: - these are devices that measure the pressures of the fluid at different positions of the hydraulic circuit. Double acting Hydraulic Cylinder :- extract energy from the fluid and convert it to mechanical energy. Such a cylinder can be extended and retracted hydraulically along a straight line path. T-connections and elbows :- these are fittings that joins two, three or four pipe lines that provide continuous flow of the fluid to different branches of the hydraulic system. Pressure Relief valve :- relief valve limits system pressure and establishes working pressure. Two position four way control valve(Manually operated type :- typically used to control the flow directions to and from double-acting cylinders. A four way valve permits the cylinder to both extend and retract under hydraulic pressure. Connecting hoses with quick acting coupling and self locking devises :- these are hydraulic system components that convey the fluid from one location to another. Safety devices such as ( on-off buttons and emergency stop button)The on-off buttons are used to start and end the operations of the hydraulic system.3.Procedures(Experimental Setup) a.We have checked that the main distribution board is in its off position.b. Next we have assembled all the components according to the attached figure. c. We have checked that all hoses and fittings are assembled in their proper position. d. Switch on the main distribution board of the power supply.4. Recording the resultThe materials that we use in this laboratory are;Stop watch, pen and paper.We have made three trials for this experiment and the output is shown as follows in the following two charts.a. Result ObservedChart-1First Trial Time(Second)Second Trial Time(Second)Third Trial Time(Second)Average time (Second)

Extension5.24.94.9 5

Retraction 4.2 4.1 4.1 4.13

Chart-2First Trial Reading(Bar)Second Trial Reading(Bar)Third Trial Reading(Bar)Average Reading (Bar)

Extension(P2)1211.211 11.43

Retraction(P3)26 26.526 26.17

b.DiscussionErrorsAs we look from the above charts the time recorded in the three trials are different value for both extended and retracted postions.And these errors comes due to :-Delaying the stop-watch starting and ending time.Error in reading the manometers at the end of the extension and retraction of the piston. OutputsLooking from chart 1, even though there is an error in the recorded time; the time taken for extension is greater than the time taken for retraction. Since for the same extension and retraction stroke length as well as the same pump flow rate it is expected that the piston retraction velocity is grater than that for extension due to the effect of the rod. And using the formula for retraction and extension time( time of retraction =Stroke/Velocity of retraction, time of extension =Stroke/velocity of extension) leads us a conclusion of extension time is to be greater than retraction.Similarly, looking from chart-2, different values of P2 and P3 are recorded in the three trial ; but we have greater amount of average pressure values for retraction stroke than extension stroke. This implies that since the rod is connected to external load the two pressure gauges measure the resistance due to the weight of piston and rod,resistance of external load and friction drop along hydraulic lines and fittings. Hence as expected, more pressure is required to retract than to extend for the same load due to the effect of the rod.

5. ConclusionWhat so ever we made errors in our experiment of this laboratory; we arrive at the following conclusion.When the rod is connected to external load compared to extension stroke less time is required to retract the cylinder.The average reading of the two pressure gauge of the extension (P2 ) is less than the retraction (P3) of the piston leading the conclusion that more pressure is required to retract than to extend. Thus more horsepower is supplied by the cylinder during the retraction stroke because the piston velocity is greater during retraction and the load force remain the same for both stroke.