Practical working of Electric jack:

With a series of pictures we will explain the process of lifting the car as our practical work to test the functioning of our project.

It was tough to find desert in Auckland but somehow we were able to. This is the picture stating the scenario of a stuck car in deserts of Auckland, similarly to the car gets stuck in dense desert. This is the actual time to test our electric jack.

At this moment we used our electric jack and placed it besides the tires as seen in the picture. It is not in a extended motion now. This picture shows the location of our jack without giving a 

lifting movement to the car.

This picture is showing the lifting that is obtained from the jack. We used the motor power to lift the jack and motor was being operated by the car battery. This was the beginning of obtaining lift through the electric jack.

Finally we got the desired lift. A very important step to remember is to fill the gap with enough amount of sand so that the car does not get stuck again. As the gap will be filled, the jack will be removed and the car will be ready to move further.

Finally we covered the gap with sand and our car is now ready to move.

Advantages of Electric Jack:

1.   As electric jack does not comprise of many parts, its weight is less which does not add more weight to the car. This gives an easy jacking to the car.
2.    Electric jack is not very costly. The design and construction is not very complex and neither heavy modification is required. So to install the jack not much money has to be paid.
3. Maintenance cost is less as it does not have more parts that require servicing. It mainly has a motor which needs to be serviced in a specific time period depending upon the usage
4.  Physical energy is not required. A person can just sit in the car and operate the switch . Operating the switch you can control the amount of lift. Thus a person can get relief from the mental and physical loads.
5.     Major Modification is not required. It just requires fitting fixtures to install the electric jack in the car.
6.  Easy installation and easy to remove: This feature adds values to the electric jack.
7. Not higher amount of battery is consumed in the operation
8.    A good lift is possible using an electric jack. Lift of approximately 14inches or more can be obtained depending on the size and specification of the jack used.
9. .  It does not require a high knowledge to install the parts so this can be done in a simple workshop too.
10.     Parts are of the common types. No extra component is required which needs to be ordered specially. All the parts included can be made available easily.
    
    
    11. Ø  It serves the purpose of lifting at cheaper rates. Time can be saved on both installation and its jacking operation.
    
    

How electric motor translates electric to mechanical?

Changign electric energy into torque energy requires the use of an electic motor. Electric energy is divide from the flow of electrons. An electric motor converts the flow of electrons using electromagnets rotate an axle. The axle then genertates torque on whatever is hooked to its open end. This entails hooking the electric motor to your power supply, be it a battery or power plug. So long as electricity flows, the current will be converted to torque.

An electric motor is used to convert electical energy into mechanical one, electric motors run by electromagnetism.

There are 3 basic elements which are interacting to produce motion:

1-    Mangntic flux (the motor housing generate magnetic field, due to the permanent magnets content)

2-    Current (when electricity is applied across the motor terminals, current flows through from one end of the terminal to the brush, commutator then to the windings, back to the commutator and brush and out through the other terminal.)

3-    Force (electromagnetic force which causes rotation of the shaft is produced by the current which flows through amgnetic field. Switching of current producing the rotating force which is called torque).

A basic electric motor has an electrical input of voltage and current. It has a mecjanical output in the form of torque and roation. The motor loses somne energy in the form of heat. An electric motor consists of two main parts, a stator, which is the outer frame and dose not turn, and a rotor, the inner part of the motor that can turn.

The rotor is connected to a shaft, which connects the machine to its mechanical load, for example the fan that turns when you switch the machine on. It is a long piece of metal that sticks out from the rotor and it turns when the rotor turns. Dpending on the type of machine, either the stator or the rotor ( or both) contain current- carrying conductors wound inot coil. These coil are called windings. There are slots cut inot the stator and the rotor to contain the windings and their insulation. There is an air gap betwwen the stator and the rotor so that they do not rub against each other. A direct current (DC) motor needs a supply of direct current to work and an alternating current ( AC) motor needs a supply of alternating current to work.

Classification of motor:

 Below is the chart giving some more details of the motor and its efficiency:

 

Specifying an electric motor

When specigying what type of electric motor is needed, the mechanical power available at the shaft is used. This means that users can predict the torque and speed of the motor without having to know the mechanical losses assoicated with the motor. Example: 10 KW induction motor.

Power:

The power output of a rotary electric motor is:

P=

Where P is in horsepower, rpm is the shaft speed in revolutions per minute and T is the torque in foot pounds.

And for a linear motor.

P= F  v

Where P is the power in watts, and F is in Newtons and v is the speed in metres per second.

Efficiency:

To calcualate a motor’s efficiency, the mechanical output power is divided by the electrical input power

η=  ,  where  is energy conversion efficiency,  is elerical input power, and  is mechanical output power.

In simplest case = VI, and = , where V input voltage is, I is input current, T is output torque, and ω is output angular velocity. Ot is possible to derive analytically the point of maximum efficiency. It is typically at less than ½ the stall torque.

Working of the Electric Jack:

Electric jack is installed in the lower portion of the car. It is located at a short distance from the tires. It has got a good covering from a black box which protects the jack from the ground, sand, water and other sources. When the car gets stuck in the desert, this covering does not penetrate more inside the sand due to its flat structure. At the time when the car has taken some depth inside the sand, it can be recovered by a simple step of operating a switch. To lift the car in desert was never an easy task. But with a usage of electric jack it is now possible. A driver can just operate a switch with 2 options of increasing or decreasing height. Once when a driver has started operating the switch by pressing the button which gives the lift to the car, battery delivers the power to the motor. This power is being transformed by the connecting wires. The location of the battery and the motor will be a bit far from each other so high quality wires with proper masking is ensured. As the motor gets the power from the battery, it starts turning. This turning movement of the motor allows the cord of the jack to turn which in return lifts the car. Motor is connected to the cord in such a way that its turning movement will be directly proportional to the raising of the jack. Once the car has started gaining height a driver can keep an eye that how much lift is required. He can also reduce the height in any case with a help of the other button available in the switch. As the desired lift is obtained, driver can simple stop the use of a switch. He can then put the gear into drive (for automatic) or first gear (for manual) and start his journey again. The electric jack will have a less force per ton than a traditional hand jack but it turns at a much faster rate. In other words, the lift we get will be slow. It may take some extra minutes to lift the car in comparison to the traditional jack. Though the motor turns at a faster rate yet the lift takes time to reach the desired height. The working of an electric jack is simple and free from complexities. It is simple to use a switch which makes the life for travellers in a desert easy.

Design of an electric jack

Design of an electric jack is very simple and clear. It does not require a lot of parts and it is free from the complexities as was involved in mechanical jack. The jack that we have proposed is the simple jack with a screw mechanism. This jack is most common type of jack that is available with almost each and every car, giving a relaxation to the people learning about a new and unknown jack. As the traditional jack uses a small handle to rotate its screw type of mechanism to get a lift, we have included a motor in that position which will do the job of that handle without using hands but by taking power from battery. The design is kept very basic so as to make situation of the people stuck in deserts very easy. Below is the original pictures of the jack that we are introducing along with the motor that will operate it. 

This picture is not an internet image but the original picture of our idea. We together have designed this concept and have practically implemented it in the workshops. Our idea was very much successful. Detailed explanation on this will be mentioned in the later paragraphs. This picture gives the clear idea of how the design is and how will be its working. Only a small modification to the jack is required. As the traditional jack uses a handle to rotate the screw mechanism to get a lift, we have introduced a motor that will be mounted to the jack as shown in figure and will use the power from battery to give a lift. Detailed explanation on the motor will be mentioned in the next few paragraphs. This motor will be connected to the battery with a set of wires as we can see in the picture. 

Parts of Electric Jack:

• Car Battery
• Jack
• Motor
• Black box
• Switch

Working of the Mechanical jack:

The basic idea of the working of the mechanical jack will be the movement taken from the drive shaft. There is a drive shaft connecting engine and the rear wheel drive to move the tires. The concept behind to move the tires is that the movement of the shaft is given to the rear wheel drive that is attached to the tires through driving axles, allowing tires to move. This concept or idea can be used for our mechanical jack too. We have discovered an idea to lift the car that is stuck in the deserts using the same concept of shaft and its movement. We will be placing jacks in front of the tires up to an extent through which we can expect a lift. This will be mechanically attached to the lower portion of the car.

The circle drawn with black color in bold is the set of worm gear attached to the shaft as per mentioned previously. The upper worm gear will be attached to the jack as per shown in the figure. Now when the car is stuck in the desert, driver will set the car in neutral position. He will then operate the first jacking lever which will set the worm gear. Worm gear will take the shaft movement now. Depending on how much lift is needed, driver can operate the other lever through the dashboard. The more lift needed, the more will be lever moved forward.

Now once the desired lift is obtained, the first lever will be again operated to release the worm gear movement. Then the driver can operate the car gears to Drive (in automatic cars) or first gear (in manual cars) and with enough acceleration car will move forward. In this way without wasting energy, car can overcome the situation of getting stuck

Working of driveshaft:

A drive shaft is a mechanical component for transmitting torque and rotation, usually used to connect other compoenets of a drive train that cannot be connected directly because of distnce or the need to allow for relative movement between them. Drive shafts are carriers of torque: they are subject to torison and shear stress, equivalent to the difference between the in the input torqure and the load. They must therefore be stronge enough to bear the stress, whilst avoiding tooo much additional weight as that would in turn increase their inertia. To allow for varivtions in the alignment and distane between the driving and driven compnoents, drive shafts frequently incorporate one more universal joints, jaw coupling, or rag joints, and sometimes a splined joint or primsatic joints.

The drive shaft is connected to the two ends, one to the tailshaft and the other to the rear differential. During driving, drive shaft is being turned by transmission which in return turns the gear in the rear differential. This is the way how torque is distributed to the rear differential from the transmission.

Limitations to Mechanical jack:

•      With an effective solution to move the car, proper modification is required. This does not come by default and not many engineers would have come across this idea so it is difficult to spread this knowledge.
•      For suppose the knowledge is spread across everywhere still the cost for this major modification will be very high 
•     Parts are not easily available so as to match the size of a gear and shaft is very difficult until and unless it is being ordered in a bulk
•      Time consuming modification with enough complexities
•      Due to the cost it will not be the first choice among customers
  
  
  
  
  
  
  Due to so many limitations we have skipped this jack and have moved to another jacking system which will not face these limitations.