Design and Fabrication of Speed Braker Power

National level conference proceeding

SREE SASTHA COLLEGE OF ENGINEERING, CHENNAI

Design and Fabrication of Speed Braker Power Generation System 1Palani 1Associate

2Assistant

3Final

S, 2Balaji Ayyanar C, 3Prasanth B 4Ranjith C

Professor, Department of Mechanical Engineering, Veltech Multitech Dr. Rangarajan Dr. Sakunthala Engineering College, Avadi, Chenna-62, India

Professor, Department of Mechanical Engineering, Veltech Multitech Dr. Rangarajan Dr. Sakunthala Engineering College, Avadi, Chenna-62, India

year, Department of Mechanical Engineering, Veltech Multitech Dr. Rangarajan Dr. Sakunthala Engineering College, Avadi, Chenna-62, India.

E-mail - [email protected] destroyed, but it can transform from one form to another”. ABSTRACT work. With the levels of non-renewable energy dwindling every day, energy conservation is the need of the hour with this objective, a speed braker power generation system is designed and fabricated in this work. Law of conservation of energy 2.0 OBJECTIVE formed the basis for this work. When a vehicle moves on the Objective of this work is to deal with the concept of road, a lot of energy is wasted, thus by intelligent systems one tapping energy from the speed brakers, when vehicle crosses can render it back as a useful energy. The proposed system over it. looks like a speed braker across the road, which is utilized to generate electric power by using the motion of the vehicle. 3.0 SCOPE OF THE SYSTEM This speed breaker will be differentiated from actual speed braker. This will be a safer system and there is no needs for A dummy speed braker power generating system can be reduce the speed, while vehicle crossing the system. installed in busy roads. So, the wasted energy can be The design and fabrication phase of this work included, the retrieved to useful electrical energy. design of components, such as spur gear, deep grove ball 4.0 PROJECT LAYOUT AND DESCRIPTION bearing, tension spring, iron plate, coupling, guiding shaft and hanger. The system fabricated successfully to complete 4.1 PARTS the working model and also results are obtained. 1. Road span or road width 2.Tension spring Keywords: Speed braker, shaft, bearings, spring, gearbox.

1.0 INTRODUCTION In this power-hungry world today each and every energy source is being examined for their potential as an energy source [1]. The rate of consumption of fuel has grown so rapidly that it possesses a threat to exhaustion of all energy resources. The vehicles of today consume far less amount of fuel than their predecessors. The energy obtained from burning of fuel gets used up in many ways. In the past few years large numbers of attempts have been made to retrieve this lost energy by dynamos, turbocharging, gear etc. But little or rather no concentration has been used on the speed braker. Every city has hundreds of roads and thousand of vehicles moving over them. A large amount of energy is spent by a vehicle traversing a speed braker. Thus, in this work an attempt is made to retrieve a part of energy, which is lost, while traversing over the speed breaker. Law of conservation of energy states that “energy can neither be created not

3. 5. 7.

Clamp 4. Spline shaft Rack 6. Free rotation and dynamo Guiding shaft 8. Base plate 9. Gear box 10. Hanger 11. Projection plate

10

2 1 3

6 4

5

11 7

9 Page 23

NATIONAL CONFERENCE ON ADVANCEMENT IN MECHANICAL ENGINEERING (NCAME’14)

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back to its initial position. The spring is stretched due to the vehicle, which moves over it. Figure 1 Layout of this work 4.2 WORKING When a vehicle moves on the road, a lot of energy get wasted, which by intelligent systems can be rendered back as a useful energy. The proposed system looks a speed braker across the road, which is utilized to generate electric power by using the motion of the vehicle. The speed braker will be differentiated from actual speed braker. This will be safer system and there is no need for the vehicles crossing the system to reduce the speed. The system will have a projection upon the road. There is a rack and pinion in a mechanism in which the top of the rack is connected to the projection plate. The down side of the rack will be under the road. The rack can make up and down motion. This perpendicular motion is converted to a rotary motion by using pinion, which is called spline shaft. The both ends of the spline shaft are connected to the bearing by supporting plate. There is a guiding shaft to guide the movement of the projection plate. This is connected to the base plate. In this system having two tension springs, one ends of the tension spring is connected to the hanger, which is away from the roadside. The other end is connected to the projection plate. When the vehicles touch the projection plate upon the road, the rack moved up and down the spring is used to render back the original position of the plate. This linear motion of the rack is converted to rotary motion by the spline shaft. The guiding shaft is used to guide the motion of the shaft. The shaft is connected to a bearing. The output of the shaft is connected to the generator to produce power.

4.3.3 Guiding shaft There are four guiding shaft which is placed on the base plate which prevents the misplacement and dislocation of the projection plate during the movement of the vehicle. It also guides and directs the correct movement of the projection plate.

Figure 2 Guiding Shaft

800

4.3.4 Coupling

15

The dynamo and the spline shaft are connected using the coupling that ensures correct alignment of both and it is responsible for the smooth motion of the shaft. 4.3.5 Plate

460

200

460

10

10

Gear Box Side Plate

300

Gear Box Back Plate 300

4.3 DESCRIPTION OF EACH COMPONENT 4.3.1 Road Span Road span is nothing by a kind of speed braker including the height, width and their relationships with the road. Unlike most usual speed braker which allows the vehicle to go over it, but in road span itself submerges to the ground when the vehicle goes over it. There by saving energy and the driver can drive smoothly being aware of the speed braker or road span. There by it acts as a partial speed braker and power saver.

10 770

Gear Box Base Plate Figure 3 Plates The whole system is placed on the base plate. It provides stability and solidity to the entire system. 4.3.6 Dynamo

4.3.2 Clamp

Converts rotary motion of the shaft to electrical energy by the principle of magnetic inductance.

They are the ending points of the guiding shaft, there main purpose is to prevent the projection plate (which includes the road span and rack) from coming out when the springs comes

4.3.7 Spline shaft Page 24


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SREE SASTHA COLLEGE OF ENGINEERING, CHENNAI Spline shaft is in contact with the rack. It plays a major role in energy conversion by converting the linear motion of the rack to rotary motion, which is connected to the generator. Module1.5 22

They are end points of the spline shaft, which allows the smooth rotary motion of the shaft. The bearings are placed in the face plate and through one bearing the shaft is connected to the generator.

15

45

127.5

32

197.5

Figure 7 Deep Groove Ball Bearing 15

Figure 4 Spline Shaft 4.3.8 Tension spring It allows the road span to submerge when the vehicle passes over it and bearings it back to its initial position then after. The ends of the spring are connected to the hanger and projection plate.

5.0 DESIGN AND FABRICATION COMPONENTS 5.1 BEARINGS [2]

3

500

Figure 5 Tension Spring 35 4.3.9 Rack It lies below the road span. It moves linearly (up and down) when the vehicle moves over the road span ensures the motion of the spline shaft. It carries the load of the vehicle. It moves back to its initial position with the help of tension spring.

M5

385

Figure 6 Rack

A bearing is a machine element, which support another moving machine element (known as journal) it is permits a relative motion between the contact surfaces of the members, while carrying the load. A little consideration show that due to relative motion between the contact surfaces, certain amount of power is wasted in overcoming frictional resistance an difference the rubbing the surfaces are in contact, there will be rapid wear. In order to reduce frictional resistance and wear and in some cases to carry away the heat generated layer of fluid (known as lubricant) may be provided. The lubricant used to separate the journal and bearing is usually a mineral oil refined from petroleum, but vegetable oils, silicon oils, greases etc., may be used. 5.2 MATERIALS USED FOR SLIDING CONTACT BEARINGS There are various types of materials can be used for bearing manufacturing with its alloys, ex: Babbitt metal, Bronzes, Cast iron, Silver and Non-metallic bearings. Everyone has its own advantages and disadvantages in working condition. 5.3 SELECTION OF BEARING 1)

45

5

25 6

25 36

4.3.10 Bearing

L = Life in hours X rpm X 60 106 = 40000 X 190 X 60 106 L = 1176 2) The dynamic load is given by C = (L/L10)(1/K) X (XFr + Yfa) X Ks Where, L - required life in 1 millions revolutions Page 25


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L10 - life of bearing for 90 % survival at 1 million Deep Groove Ball Bearing revolutions X =1 F - radial load coming on the bearing Y =0 Fa - axial load coming on the bearing Fa =0 Ks - service factor C = (1176)(1/3) X (1 X 280 + 0) X 1.5 - 1.1 to 1.5 for rotary machines = 10.53 X 270 X 1.5 X and Y - radial and axial factors an exponent - 3 for ball C = 4264.65 N bearing Basic Dynamic Capacity C = 435 kgf Values of X and Y for dynamic load. Corresponding Values Of Static Basic Capacity In Kgf The Life in Million Revolutions From Data Book Is C0 = 255 Kgf K = 3 (For Ball Bearing) Ks = 1.5 Fr = 270 N Table 1 Deep Groove Ball Bearing [6] Bearing of basic design no (SKF) 6002

d mm

D1 min

D mm

D2 mm

B mm

r mm

R1 mm

Static C0

Dynamic C

Max Permissible speed (rpm)

15

17

32

30

9

0.5

0.3

255

440

20000

5.2 DESIGN OF SHAFT [3] 1) Torsional shear stress () = P/A (N/mm2) P = Force or load acting on the shaft (55 Kgf), A = Cross section of the body (0.045 X 0.036 mm2) 2) Twisting moment (or torque) acting upon the shaft (T) = (/16)  d3  = Torsional shear stress (333055.5 N / mm2) d = Diameter of the shaft ( 0.015 mm) 3) Tangential force on the gear (FT) = 2T/D (N) T = Torque transmitted by the shaft ( 0.220 N-mm) D = Pitch circle diameter of gear (0.022 mm) 4) Normal load acting on the tooth of gear (W) = FT / cos  (N) = 22.28 N  = Pressure angle of the gear (200) 5) Maximum bending moment at the centre of gear M = WL / 4 (Nmm) = 1.596 N-m L = Length of shaft (300 mm) 6) Equivalent twisting moment (Te) = = 1611 Nmm

M 2  T 2 (Nmm)

5.3. DESIGN OF SPRING [3] 5.3.1 Material used for spring The material used for spring should have high fatigue strength, high ductility, high resilience and creep resistant. The following values used for a spring design. 1. Solid Length (Ls) = n’d (mm) n = Total number of coils (169) d = Diameter of the wire (3 mm)

2. Free Length = Solid length + Maximum Compression (500 mm) + Clearance between adjacent coils (or clash allowance) = n’d + max + 0.15  max = n’d +  max + (n’-d) X 1 (mm) 3. Spring Index (C) = D/d D = Mean diameter of coil (33.5 mm) 4. Wahl’s Stress Factor

 4C  1   0.615  K     4C  4   C  5. Deflection Of Spring () = 8WD3 (mm) Gd4 Modulus of Rigidity (G) = 80 Kgf / cm2 6. Spring Rate (K) = W/ (N/mm) W = Load (539N)  = Deflection of the spring (4281.63 mm) 7. Pitch of the coil (P) = Free length n’-d 8. Maximum Shear Stress Induced () = K8WC N/mm2 3.14 d2 9. Deflection per Active Turn /n = 8WD3 mm Gd4 10. Outer Diameter of the Spring Coil DO = D + d mm 11. Inner Diameter of Spring Coil Di = D – d mm Table 2 Tension Spring Design Results Spring dimensions Mean diameter of coil (D)

Values 33.5 mm Page 26


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SREE SASTHA COLLEGE OF ENGINEERING, CHENNAI Diameter of wire (d) Spring Index (C) Solid Length (Ls) Free length (Lf) Deflection of spring () Deflection per active turn ( / n) Spring rate (K) Pitch (P) Maximum shear stress induced () Outer diameter of the spring coil (D0) Inner diameter of the spring coil (Di)

3 mm 11.66 mm 507 mm 1173 mm 4227.90 mm 25.017 mm 0.1275 N/mm 7.066 mm 1997.951 N / mm2 36.5 mm 30.5 mm

5.4 DESIGN OF SPUR GEAR [4] 5.4.1 Materials used for Spur gear The material used for the manufacture of gears depends upon the strength and service condition like wear, noise etc,. The gears may be manufactured from metallic or non-metallic materials. The metallic gears with cut teeth are commercially available in cast iron, steel and bronze. The non-metallic materials like wood, rawhide, compressed paper and synthetic resins like nylon are used for gears, especially for reducing noise. Cast iron is mostly used for the manufacture of the gears due to its good wearing properties, excellent machinability and ease of producing complicated shapes by casting method. The steel is used for high strength gears and steel may be plain steel or alloy steel. The phosphor bronze is widely used for worm gears in order to reduce wear of which will be excessive with cast iron or steel. 5.4.2 Calculations: Material Selection C45: For Designing Design surface (contact compressive) Stress [c] = CRHRC Kcl (Kgf / cm2) CR = Coefficient depends on the surface hardness (265) HRC = Rockwell hardness number (55) Kcl = Life factor (1) Design bending stress (tension) [b] = Kbl-1 (N / mm2) nk Rotation both directions, Kbl = Life factor for bending (0.22) -1 = Endurance limit stress in bending for complete reversal of stress, (Kgf / cm2) (0.22 ( 6500 + 3600) + 500) n = Factor of safety (2.5) k = Fillet stress concentration factor (1.5)

a   i  13

Centre Distance

0.74 X 2 EX [ Mt ] [c]i

(mm) i = Standard gear ratio (Z1 / Z2) Z1 = Number of teeth in driving gear Z2 = Number of teeth in driven gear E = Equivalent young’s modulus (Kgf/cm2) [Mt] = Design twisting moment = Mt X KdK Mt = Nominal twisting moment transmitted by the pinion (Kgf / cm2) Kd = Dynamic load factor K = Nominal power transmitted in KW Mt = 97420 KW n = 97420 X 0.118 490 = 2.2 [Mt] = 2.2 X 1.3 = 2.88 a = m X (Z1 + Z2) 2 = 1.5 X (12 + 12) 2 a = 18 mm 0.74 X 2 X 2.15 X 106 X 2.88 a  1  13 [14575]2 X 1X .7 18  5.72mm Module

m3

[ Mt ] y[ b ]mZ

y = Form factor corresponding to Z1 from table [0] = Design bending stress (tension)  = b / m = 10 in general 2.88 m3 0.308 X 725.86 X 10 X 12

m  0.59

5.4.3 For Checking: Surface Compressive Stress Surface compressive stress i 1 i 1  C  0.74 E M t    c a ib b = face width b = i + 1 [Mt]  [ b ] amby y = form factor corresponding to Z1 from table

11 11 2.15 X 10 6 X 2.88   c .572 1X 0.399 14414.8  14575 b = i + 1 [Mt]  [ b ]

 C  0.74

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SREE SASTHA COLLEGE OF ENGINEERING, CHENNAI =

(1 + 1) X 2.88

 [ b ]

7.0 ASSMBLY

0.572 X 1.5 X 0.399 X 0.308 = 54.62 Kgf/cm2 54.62  725.86 The design value is safe, so module of spur gear can select as 1.5 mm. Table 3 Spur Gear Design Results Specifications Design surface Stress (contact compressive) [c] Design of bending stress (tension) [b] Centre distance (a) Module (m) Surface Compressive stress (c) Design Bending Stress (tension) (b)

Values 14575 Kgf/cm2 725.86 Kgf/cm2 5.72 mm 1.5 mm 14414.8 Kgf/cm2 54.62 Kgf/cm2

6.0 FABRICATION Rack and pinion mechanism involves the fabrication of spline shaft, spur gear. The blank to manufacture spur gear was turned diameter of 22 mm and faced to a length of 45mm. The module selected is 1.5 mm, pressure angle is 200, and depth of tooth is 3.75 mm. The spur gear material is made of mild steel. The material selected for rack is mild steel. A rectangular block 385 X 45 X 36 mm is taken, the module for rack is 1.5 mm, tooth depth is 3.75 mm. These data are taken for manufacturing. The spring is with the stiffness k = 0.1167 N / m, spring diameter 35 mm and coil diameter is 15 mm. Plates of dimensions 10 X 200 X 460 mm (two plated), 10 X 300 X 460 mm and 10 X 300 X 770 mm were used for manufacturing the system. After the fabrication of the components assembly of all components is taken. Assembling is the arrangement of the components fabricated in a fashion or way that would result in the proper working of a machine. The first stage of this process involved the assembling of gearbox mechanism in the project. Gearbox was assembled with the help of four plates. These plates was fastened with the help of arc welding. The spline shaft was then inserted in the holes drilled in the side plate. Deep groove ball bearing was provided so as to permit a relative motion between the contact surface of the end shaft. The next stage involved the assembling of the rack and pinion mechanism on the gearbox. Rack is connected to the projection plate. One end of spring was attached to a hanger and the projection was hung from the other end. The whole assembly was installed on a foundation that consumed very little space. Testing of a model is done. So that minor adjustments needed are carried out so that it resulted in smooth operation of the model.

After the fabrication of the components and with the parts available process of assembly was started. Assembling is the arrangements of the components fabricated in a fashion or way that would result in the proper working of machine. The first stage of this process involved the assembling of gearbox mechanism in the project. Gearbox was assembled with the help of four plates. These plates is fastened with the help of arc welding the spline shaft was then inserted in the holes drilled in the side plate. Deep groove ball bearings are provided so as to permit a relative motion between the contact surfaces of the end shaft. The next stage involved the assembling of the rack and pinion mechanism on the gearbox. Rack is connected to the projection plate. One end of spring was attached to a hanger and the projection was hung from the other end. The whole assembly was installed on a foundation that consumed very little space. Testing of model was done. So that minor adjustments if needed are carried out so that it resulted in smooth operation of the model.

8.0 RESULTS AND ANALYSIS The first objective of the project is to convert the minimum reciprocating motion into maximum rotary motion. The second objective of the project is utilization of law of conservation of energy that is converting the mechanical energy to electrical energy. In this project the achievement of maximum rotary motion in each and every stage give below. Specifi -cations

Stroke length (mm)

Output from gearbox (rpm)

Rotation of motion in fly wheel (rpm)

End rotation motion bevel gear output (mm) 27954 373v

rpm 385 450 1025 Generator -6v 12v voltage from dynamo Calculation: 450 X 2.5 = 1025 2r = 2 X  X 300 =1884 mm 2r = 2 X  X 11 = 69 mm P = 1884 / 69 = 27 Analysis: The above discussion and tables we can coupled 6v, 12v, 373v at different stages. Eg = N

Zn 60

=

X

P = 13.33 X 10-3 A

Eg Constant Page 28


11TH SEPT, 2K14



Eg

= 27954 X 13.33 X 10-3 = 373 V These energy can be stored in Battery operated cars, streetlights, traffic signals, etc.

9.0 CONCULUSION A dummy speed breaker power generating system can be installed on busy roads, so, that the wasted energy can be retrieved to useful electrical energy. In this work, the model of a dummy speed breaker power generation system is designed and fabricated. The system is tested for power generation. A small amount of power is generated using this system, which is used to emit a LED bulb. A dynamo is used for producing electric current. The rotation of dynamo is obtained, using rack and pinion arrangement, which is installed below the ground level.

10.0 FUTURE SCOPE For further improvement on the current work, high speeds may be obtained by using bevel gears, coupled with the flywheel. Thus more power may be generated. The spring used in the project can be replaced by Hydraulic or pneumatic system. Rack and Pinion Mechanism can be replaced by a four bar mechanism. A multiple gears can be implemented in gearbox to increase the speed. This system can be used as a power production as well as energy storage plant.

REFERENCES 1. 2. 3. 4. 5. 6.

G.D. Rai, “Non-conventional Energy Resources”, Khanna Publishers, 1996. T.V. SundraRajamoorthy and N. Shanmugam, “Machine design”, Anuradha Agencies, 2000. R.S. Khurmi and J.K. Gupta, “Machine Design”, Eurasia Publishing House Pvt Ltd, 2003. T.J. Prabhu, “Design of Transmission Elements” 2002. S.K. Hajra Choudury, A.K. Hajra Choudhury, “Elements of Workshop Technology”, Media Promoters of Publishers Pvt.Ltd., Vol. II, 1997. Faculty of Mechanical Engineering, “Design Data”, Karthi Achagam, 2004.

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