ABSTRACT With the increasing levels of technology, the eorts being put to produce any kind of work has been continuously decreasing. The eorts required in achieving the desired desired output can be eectively and economically economically be decreased by the implementation of better designs. A Hydraulic ack is an e!ample of hydraulic machinery in which a small force applied in a hori"ontal plane is used to raise or lower a large load. The principle on which it works is similar to that of an inclined plane. The mechanical advantage of a hydraulic ack is the ratio of the load applied to the eort applied. The screw ack is operated by applying force on handle. The height of the ack is adusted adusted by turning turning a release release valve valve and this adustment can be done either manually or by integrating an electric motor. #n this proect, an electric motor will be integrated with the hydraulic hydraulic ack and the electricity needed for for the operation will be taken from the battery of the vehicle and thereby the mechanical mechanical advantage will be increased.
$eywords% &.' motor, (ifting Arm, )ear ratio, speed reduction.
Table T able of 'onten 'o ntents ts I.
Introduction
#. ##. ###. #. #.
Hydraulics *ascal+s law Hydraulic ack Types ypes of hyd hydraul rauliic ac ack k
II. Components #. ##. ###.
-ottle Hydraulic ack &' motors / circuit
III.. Con III Constr struc uctio tion n and work working ing of of jack jack #. ##. ###. #.
Hydraulic cylinder elea eleas se va valve me mechanism (ever me mechanism / circuit
IV.. Ima IV Images ges of hy hydra drauli ulic c jack jack V. t the her r co con nsi side der rat atiion ons s #. ##. ###. #. .
0aintenance of of a ack 1perating ting instructi uctio ons 2afety ety ins nsttruc ructions Application 'omparative study
Conclusion
Table T able of 'onten 'o ntents ts I.
Introduction
#. ##. ###. #. #.
Hydraulics *ascal+s law Hydraulic ack Types ypes of hyd hydraul rauliic ac ack k
II. Components #. ##. ###.
-ottle Hydraulic ack &' motors / circuit
III.. Con III Constr struc uctio tion n and work working ing of of jack jack #. ##. ###. #.
Hydraulic cylinder elea eleas se va valve me mechanism (ever me mechanism / circuit
IV.. Ima IV Images ges of hy hydra drauli ulic c jack jack V. t the her r co con nsi side der rat atiion ons s #. ##. ###. #. .
0aintenance of of a ack 1perating ting instructi uctio ons 2afety ety ins nsttruc ructions Application 'omparative study
Conclusion
I.
Introduction
3A44 Hydrau 3A Hydrauli lics cs %5 Hydrau Hydraulic lics s is a 6eld 6eld of applie applied d scienc science e and engineering dealing with the mechanical properties of 7uid. /luid mechanics provides the theoretical foundation of hydraulics, which focuses on the
engineering uses of 7uid properties. #n 7uid power, hydraulics is used for the generation, control 8 transmission of power by the use of pressuri"ed liquid. Hydraulic range through most science and engineering disciplines, and covers concepts such as pipe 7ow, dam design, 7uidics and 7uid control circuitry, pumps, turbines, hydropower, computational 7uid dynamics and 7ow measurement.
Basics of !ydraulics" I. Classifcation o hydraulics a)Hydrostatics:/luid statics or hydrostatics is the branch of 7uid mechanics that studies 7uids at rest. #t embraces the study of the conditions under which 7uids are at rest in stable equilibrium9 and is contrasted with 7uid dynamics, the study of 7uids in motion. Hydrostatics oers physical e!planations for many phenomena of everyday life, such as why atmospheric pressure changes with altitude, why wood and oil 7oat on water, and why the surface of water is always 7at and hori"ontal whatever the shape of its container.
b) Hydrodynamics:Hydrodynamics refers to the study of liquids in motion. #t usually determines the 7ow of 7uids and a good e!ample would be a pipeline and the 7ow of
petroleum though it. This branch of study is part of a larger 6eld called hydraulics that studies how energy and forces interrelate with 7uids.
II.
Pressure
*ressure is a force e!erted against a speci6c area 3force per unit area4 e!pressed in psi 3pounds per square inch4, -ar, or *ascal. *ressure can cause an e!pansion, or resistance to compression, of a 7uid that is being squee"ed. A 7uid is any liquid or gas 3vapor4. An e!ample of the pressure is the air 3gas4 that 6lls an automobile tire. As a type is in7ated, more air is squee"ed into it that it can hold. The air inside a tire resists the squee"ing by pushing outward on the casing of the tire. The outward push of the air is pressure. :qual pressure throughout a con6ned area is a characteristic of any pressuri"ed 7uid. #$ %&A
Common symbols
P
SI unit
Pascal (Pa)
In SI base units
III.
Force
1
kg/(m·s2)
The force is an e!ternal agent which produces or tends to produce change in the state of rest, motion shape or si"e of an obect and is e!pressed in ;ewton. #t is a vector quantity. The ;ewton is 2# unit for force. An e!ample of force is to raise a body, to displace a body from one place to the other, to stop a moving body etc. The relationship of force, pressure, and area is follows% %$ #.A
Common symbols
F ,
F
SI unit
newton
In SI base units
1 kg·m/s2
Derivations from other quantities
F = m a
3-4 *ascal+s law %5 -laise *ascal formulated the basic law of hydraulics in the mid of <= th century. He discovered that pressure e!erted on a 7uid is equal in all directions. His law states that pressure in a con6ned 7uid is transmitted undiminished in every direction and acts with equal force in equal areas and at right angles to container+s wall. According to this law, >#n a closed liquid the pressure applied at any part is equally transmitted in all the directions and in the same amount?. 1 >#f a liquid is in equilibrium then the pressure in the every part of it is equal?.
/ig. *ascal+s law
3'4 Hydraulic ack %5 Hydraulic acks are typically used for shop work, rather than as an emergency ack to be carried with the vehicle. @se of acks not designed for a speci6c vehicle requires more than the usual care in selecting ground conditions, the acking point on the vehicle, and to ensure stability when the ack is e!tended. Hydraulic acks are often used to lift elevators in low and medium rise buildings. A hydraulic ack uses a 7uid, which is incompressible, that is forced into a cylinder by a pump plunger. 1il is used since it is self5 lubricating and stable. When the plunger pulls back, it draws oil out of the reservoir through a suction check valve into the pump chamber. When the plunger moves forward, it pushes the oil through a discharge check valve into the cylinder. The suction valve ball is within the chamber and opens with each draw of the plunger. The discharge valve ball is outside the chamber and opens when the oil is pushed into the cylinder. At this point the suction ball within the chamber is forced shut and oil pressure builds in the cylinder. Hydraulic ack is a device used for lifting automobile 8 heavy machines. Thus a hydraulic ack is mechanical arrangement that uses the power of 7uid to lift heavy obects.
3&4 Types of hydraulic acks %5 3#4 -ottle hydraulic ack #n a bottle ack the piston is vertical and directly supports a bearing pad that contacts the obect being lifted. With a single action piston the lift is somewhat less than twice the collapsed height of the ack, making it suitable only for the vehicles with a relatively high clearance. /or lifting structures such as houses the hydraulic interconnection of multiple vertical acks through the valves enables the even distribution of forces while enabling close control of lift.
/ig. -ottle hydraulic ack
3##4 Hydraulic 7oor ack #n a 7oor ack a hori"ontal piston pushes on the short end of the bell5crank, with the long arm providing vertical motion to the lifting pad, kept hori"ontal with hori"ontal linkage. /loor acks usually include castors and wheels, allowing compensation for arc taken by the lifting pad. This pro6le provides low pro6le when collapsed, for easy operating underneath the vehicle, while allowing considerable e!tension.
/ig. Hydraulic 7oor ack
3###4 2trand hydraulic ack A strand ack 3also known as strand5ack4 is a ack used to lift very heavy 3e.g. thousands tons or more with multiple acks4 loads for construction and engineering purposes. 2trand acks were invented in :urope in the
/ig. 2trand hydraulic ack
3#4 Toe hydraulic ack 5
/ig. Toe ack
II. Components 3A4 -ottle Hydraulic Dack %5 &escription%5 A bottle hydraulic ack operates on principle of *ascal+s (aw. -ottle or hand acks, came into wide spread popularity during the early part of the ECth 'entury, paralleling the boom of the automobile industry. They 6lled the immediate need of a small convenient device requiring only one person to operate that could lift an automobile o the ground for servicing 5 #t quickly found hundreds of other uses in the modern world, as well.
A bottle ack or whiskey ack is a hydraulic ack which resembles a bottle in shape, having a cylindrical body and a neck, from which the hydraulic ram emerges. They have a capacity of up to FC tons and may be used to lift a variety of obects. Typical uses include the repair of automobiles and house foundations. (arger, heavy5duty models may be known as a barrel ack. This type of ack is best used for short vertical lifts. -locks may be used to repeat the operation when a greater amount of elevation is required.
/ig. *1: drawing of bottle hydraulic ack
3-4 &c motors %5 0otor is a device which converts electrical energy into mechanical energy. &' motors are electric motors that are powered by direct current 3&'4, such as from a battery or &' power supply. Their commutation can be brushed or brushless. The speed of a brushed &' motor
can be controlled by changing the voltage alone. 'onsequently, motors that are powered by A' require a change in frequency to change speed, involving more comple! and costly speed control. This makes &' motors better suited for equipment ranging from
3'4 / circuit %5 &escription%5 / G channel remote control is a combination of / transmitter with G switches and / receiver contains G relays, which can be controlled wirelessly. This makes the unit very easy to operate and integrate with e!isting systems. $eys < to G on the remote control operate the corresponding relay on the receiver board, i.e. button < operate relay <, button E operate relay E, like this. /eatures of receiver5 3<4 3E4 34
/our channels each individually controlled elay indicator (:& eceiver operates from
/eatures of transmitter5 3<4 3E4
G button each individually controlled Transmit data indicator (:&
34 Transmit operating range up to
2moke 8 6re alarm system )arage door controllers 2ecurity system 'ar alarm systems
/ig. / reciever circuit
/ig. / transmitter circuit
III. Construction ' working of jack A.
'onstruction 8 working of hydraulic cylinder%5
The cylinder fabricated for the ack has a sleeve in which the piston reciprocates during operation. The cylinder material is cast iron and welded with an iron base plate. The plate is gas welded below the hollow cast iron cylinder. There is an opening for oil in the base of cylinder. A cast iron head cover is designed for covering the cylinder from upper end. The piston has an oil rubber to seal the 7uid in cylinder during operation. The piston rod is 6tted with the piston and screw nut on the other end. The hear cover is locked with the help of circlip lock. A hole is made in the head cover to release air from the upper hollow portion of cylinder while reciprocating motion. When 7uid pushed by the pump into the cylinder from the inlet opening given below, it pushes the piston up in the cylinder and thus linear motion is obtained by displacement of piston in the cylinder.
-.
'onstruction and working of release mechanism%5
valve
elease valve is used to release the pressure from hydraulic cylinder. #n normal release valve is rotated by hand. -ut in this ack it is operated with the help of motor. 1pening of release valve causes release in pressure i.e. ram is lowered. When release valve is closed it maintains applied pressure inside the hydraulic cylinder, thus ram is raised. *ressure control valve is operated by motor which is mounted on the base plate. 0otor moves on clockwise or anti clockwise direction according to polarity. When motor rotates in clockwise direction then pressure release valve is closed and if polarity is reversed motor rotates in counterclockwise direction causing valve to open. 0otor is operated by means of / circuit.
/ig. *1: drawing of release valve motor
'.
'onstruction mechanism%5
and
working
of
lever
To create the pressure eect in the large cylinder which contains ram oil pumping has to be done in the small cylinder. )enerally oil pumping is done with the help of a rod. od is moved in up and down direction by hand so as to create pressure and lift the ram. This movement of rod can be done by means of motor. 0echanism similar to slider5crank mechanism can be used to achieve up5down movement of rod. As lever requires reciprocating motion the motor output should also converted into reciprocating motion. A &' motor gives rotary motion as an output. A simple slider crank mechanism can convert rotary motion into reciprocating motion. Thus a motor shaft is 6!ed with a plate provided with a crank. This crank is then connected to lever. Thus when motor starts crank gives reciprocating motion to the lever as required.
/ig. *1: drawing of oil pimping mechanism
/ig. *1: drawing of lever mechanism motor
&. Working of / circuit%5 eceiver circuit is connected to battery of
eceiver circuit has decoder which gives signals consequently and startsIstops circuit as required.
IV. Images of hydraulic jack
/ig. *1: drawing of HJ&A@(#' DA'$
V. ther considerations 3A4 0aintenance of ack %5 When the ack is not in use, keep the cylinder fully retracted. 2tore the ack on its base and in well protected areas where it will not be e!posed to any corrosive vapors, any other abrasive dust or any other harmful elements. isually inspect the ack before use. Take corrective actions if any of the following problems are found%5
'racked or damaged housing :!cessive wear, bending or other damage (oose hardware (eakage of hydraulic 7uid
2ome maintenance techniques associated with hydraulic ack% <. When the ack is not in use, piston must be in their lowest positions to minimi"e corrosion. E. $eep the ack clean and lubricate all moving parts with acid free oil on a regular basis. . To check oil level, fully lower the ack. emove the 6ller plug. The correct oil level is to the bottom of the 6ller plug opening. G. After a year of e!tensive use, the oil should be replaced.
F. To replace the oil 6ll as required. *ump 3unloaded ack4 F or K times to e!pel air. *ump ack to full height and pour o e!cess oil before re6tting plug. K. *eriodically check the pump piston and piston rod for signs of corrosion. 'lean e!posed areas with a clean oiled cloth.
3-4 1perating instructions%5 <. 'heck that the ground upon which the ack will stand is level and solid. E. *osition the ack saddle under the vehicle manufacturers recommended lifting point. . @sing the screw e!tension necessary raise the saddle to the lifting point. G. *ump the unit until the required height is achieved. F. :nsure that the suitable a!le+s stands are provided and removed after and before acking. The lowering speed is controlled by the amount of release valve is opened. Turn anti5clockwise and lower slowly and carefully.
3'4 2afety instructions%5 <.
egularly inspect and lubricate ack to ensure it in good working order and condition. &oes not use the ack if damaged or a fault is suspected5check section F troubles shooting. #f necessary, immediately repair or replace damaged parts.
E. . G. F.
K.
=.
L. B.
@se recommended parts only9 the use of unauthori"ed parts may be dangerous. @se ack on level and solid ground, preferably concrete. *ark the vehicle and apply hand brake. 2witch o the engine and place chokes under the wheels. :nsure a minimum distance of C.F m between vehicle and static obects such as doors, walls, etc. to allow for tilting during acking. :nsure all persons are out of the vehicle before acking. &o not enter vehicle whilst it is supported on the ack or a!le stands. 'heck lifting point is centered and stable on ack saddle. *ositions ack so as to avoid, operating it from under vehicle. $eep hands etc. clear of moving parts during raising and lowering of the vehicle. &1 ;1T e!ceed the rated capacity of the ack and do not operate the ack beyond its ma!imum pump stroke. &1 ;1T try to move the vehicle, or try to start the engine, when the vehicle is acked up. &1 ;1T ack a vehicle if it may result in the spillage of fuel, battery acid, or other dangerous substances. &o not place any part of your body under vehicle whilst it is supported by the ack. &1 ;1T use ack to support e!tensions or cradles. &1 ;1T top up ack with brake 7uid. @se hydraulic oil only. &o not adust the safety overload valve.
3&4 Applications%5 In the automotive world the 1 1/2 through 5 ton jacks are popular for cars and light trucks, the 8 and 12 ton models for Recreational Vehicles and medium to heav dut trucks while the 2! ton "ottle jacks are used primaril for #"ig rig# tractor trailers$ %ottle jacks and variations thereof appear in fields as diverse as medicine &for patient lifts, e'amine ta"les, hdraulic stretchers(, plum"ing &pipe "enders(, electrical &ca"le slicers(, printing &paper cutters( warehousing &material handling(, agriculture &e)uipment maintenance(, construction &pushing, pulling, hoisting or lifting(, food industr &from pallet jacks to pressing apple juice or sausages( metal shops &"ending, cutting and fa"ricating( and in do*ens of applications too numerous to mention$
3:4 'omparative study%5 @sually normal hydraulic acks are used to lift heavy vehicles 8 small cars. 0ore energy and physical work is required to lift such a heavy load. While in case of automatic hydraulic ack power required to lift load is less. 2o that automatic hydraulic ack is easy in use. #n case of automatic hydraulic ack, operator is not near the
ack so that it will not harm an operator. While it is not safe for operator in case of normal ack if any failure occurs. ;ormal hydraulic ack is operated by person so time required to lift load is more. 2ince automatic hydraulic ack operates electrically so that operation is completed in less time.
