A Review on Ergonomic Design and Development of Flywheel in Exercise Equipment for Energy Generation

In this present paper the ergonomic design and development of flywheel in exercise equipment is studied. Nowadays in developing countries like India lots of energy crisis are there thus we should be aware about new methods of generating energy to overcome these problems. Here we are mainly focusing on electricity generation through human power. Properly designed mechanisms are useful to convert these human efforts into electrical energy using ergonomic and tribological considerations. Flywheel is also added in the design so as to minimize human efforts for continuous constant power


INTRODUCTION
In today's modern society, most people just flip a switch or push a button, and everything we depend on is readily available. Cell phones, computers, televisions, heated water, lights, and so much more, are all the backbone of any modern Society's functionality. The electricity powering all these systems is something most people rarely think about until the power is no longer available for use. The extensive system that allows for an instant and near constant supply of Conditioned power is referred to as the grid. This grid is usually supported by government and/or private in developed countries; a government must have enough financial resources to establish and support a significant investment to provide the service of electricity. [8]  The project's main Moto is simply to charge a battery array with a produced 24V DC from the stationery frame with all attachments design; however, for this project design to be considered successful for some objectives like primary and secondary as Low Production Cost, High Safety, High Energy efficiency Low Upkeep, High Product Durability, Use For Exercise purpose in gym etc. Project design and modifications are affordable because we used stainless steel stand, used alternator and wiring arrangement and battery etc.

METHODOLOGY AND DESIGN
This project has discrete design ways to complete our product while meeting the majority objectives. This means we will have to implement and correlate our different designs to assure the best product based on our set of objectives.

Design of a Frame
While designing a frame, engineers usually makes use of an older design which has proven reliable as a starting point.
The frame of the POPG created to reflect a typical Schwinn DX bike exerciser with small modifications on the materials used in order to minimize cost and considering availability of materials. Steel gives the excellent combination of performance when a steel frame dismantles, it tends to break gradually rather than suddenly and they have the capability to store and discharge energy at distinct degrees of the pedal strokes.

Design of pedaling Mechanism
Commonly, the bicycle pedaling mechanism converts human energy into mechanical energy for transportation purposes and with our system mechanical energy into electrical energy by alternator. The human musculature is concentrated in our legs and the pedaling mechanism set-up grant for mobilizing the maximum output. The flywheel is an ideal prime mover for electrical generation in this set up; we would need to couple an alternator and flywheel through either direct contact or a belt system. When with the help of pedaling we rotate the flywheel which stabilizes after some time and gains more speed, then the user downshift thereby increasing perceived resistance and outputs more power. The first step while designing the project is the construction of the stand for the all attachments of the project, which are resting on it. As our goal behind designing this project to build a multipurpose machine for generation of electricity so, we welded all stainless steel hollow bars perfectly to form a frame like structure. By using stainless steel hollow bars we avoided the negative aspect of metal frame from the issues of heavy weight and corrosion from the user or the environment or both. For the stand to be able to handle the vertical and lateral motions of the users, a wide and solid base is necessary. The frame arrangement design has made to withstand a great amount of force from the user and steel maintain its performance and form.

Alternator
The last practical option to implement for the pedaling system was to use a standard car Alternator expect Motor and Car alternator. This seems to be the most reasonable motor for the design, as car alternators are widely available worldwide for relatively low costs when purchased as a used part. There are some issues while using alternator. The first issue is the power loss due to conversion from AC to DC voltage. Most alternators automatically convert AC to DC in the regulator of the part there is still the power loss in the alternator that will reduce the efficiency of the product and waste some of the energy exerted by the user. Another major issue when using an alternator occurs at the speed at which the part operated. When a car is idling, the rpm of the motor can be seen in the odometer. This value is usually around 600-700 rpms. Alternators usually run at a 3:1 rpm ratio due to the diameter difference in the motor and alternator head. This means an alternator is more efficient at speeds of 2100 rpms and higher [3]. For our testing and model design, we used a Maruti 800 TVS alternator. The rewrapping of the stator or rotor would have to be with thinner gauge wire in order to increase the number of turns by this we increase the current output at less RPMs.
The finger poles on the rotor actually bend the magnetic field of the rotor around the shaft in order to obtain the electromagnetic induction between the rotor and stator that produce the electrical power. From Faraday's equation, = -N dB/dt, we find that as N (number of turns) increases, (electromagnetic force) increases proportionally.
Alternator Mounting and Wiring should be correct to produce power it should be securely fastened to the stand and connected correctly to the flywheel rim and all other components. Alternators are very durable when connected correctly, but if connected incorrectly the alternator may be destroyed very quickly. [4] Figure 7. 2 SMF Dry Battery is used both are 12V 7.6 Amp SMF battery, which means Sealed Maintenance Free battery, which is sealed completely because there is no need to add water. The electrolyte used is in the form of gel, which fills the cavity of plates. Just like other batteries, it also emits H2 and O2 gases and due to sealed batteries both these gases combine to form water. Batteries connected in Series so current are Constant and Voltage changes.  Above assembly having 70 teeth sprocket at one side and 24 teeth sprocket at other side of energy flywheel. This Energy flywheel operation relates to the dual mass flywheel (DMF) concept.

Fig.9: Dual Mass Flywheel System
From Fig. 9 it is clear that in addition to the mass of the flywheel, the couple owing to the centrifugal and centripetal forces keeps the flywheel into motion for longer time thereby increasing the work done by the system hence the output from the given system increases. [9] The arrangement of the dual mass flywheel is best explained by the mathematical model below. The model is a two spring two mass model graphically represented as below  fig.10 shows free un-damped vibrations set up of two mass-two spring system. As shown in the figure the input to the system is in the form of an low energy intermittent input from any power source (excitation), this results in free undamped vibrations are set up in the system resulting in the free to and fro motion of the mass (m1) & (m2), this motion is assisted by gravity and will continue until resonance occurs, i.e. the systems will continue to work long after the input (which is intermittent) has ceased. Hence the term free energy is used. [9]  In the first level an equipment/ machinery must be safe while in contact with human beings.  In the second level, an equipment/ machinery must not produce harmful effects in human beings over longer periods.  The third level, an equipment/ machinery must be physically comfortable, that is, it should not require excessive efforts, both physical and mental or visual.  In the fourth level an equipment/ machinery should provide mental satisfaction i.e. it gives a feeling of pleasure to the human being using the same.  The fifth level is the determining the degree of modernity of an equipment/ machinery ergonomic considerations must constitute an essential factor of the social profitability of the equipment/machinery.

Fig.11: Adjustable chair
We attached a fiber material chair on the steel frame structure as shown in above figure having base dimension as 46×43 cm and height 43 cm. Therefore, the peddler may sit comfortably and pedal. Where, S1, S2, S3, and S4 are the Sprockets use respectively in gear trains.

Now for first gear train between shaft 1 and 2
Therefore, rev. Now 2nd and 3rd sprocket is on same shaft so, N2 = N3 = 2

For Modified Cycle
To overcome losses and to improve system modification in system and to reduce losses we must do following modifications,