Projects

PROJECT NO.1 AIM: - To make Hardness chart of various parts of tractor so that ease in checking the incoming quality of various components.

REQUIREMENT OF HARDNESS CHART  If any component which is come under line rejection in quality control for mainly hardness then there is no need to open the control plan of that components, simply see the hardness of that component from hardness chart and check it again with suitable instrument.  It is easy to locate the component control plan from the file by note the component part no. from the hardness chart.  It is beneficial for trainee students and for trainee engineers that they not know hardness of various components of tractors.

CONTROL PLANS USED FOR MAKING HARDNESS CHART  Rear Cover  Front Axle  Differential  Gear and Shafts  Gear Box  Hardware

HARDNESS CHART FOR DIFFERENTCOMPONENTS REAR COVER S.NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

PART NO. 401004 401007 401010 401011 401013 401017 401020 402008 402010 405009 405016 403007 402018 104005 403006 104006 403002 104004 401023 4010106 402021 402016 405023 405013 405007

DESCRIPTION POSITION ACTUATOR ASSY. POSITION LINK ASSY. DRAFT LINK ASSY. SENSOR LEVER HINGE PIN SENSOR (L-42) SENSOR ROD PIN ROCKER LINK CONNECTING ROD LIFT ARM ASSY. POSITION CRANK ASSY. RETAINING PIN (BIG) RESPONE VALVE LINEAR LINK PIN BALL SHEET LINCH PIN PLUG PIN PIN SWIVEL PIN INSERT ROCK SHAFT DRAFT LEVER ASSY. POSITION LEVER ASSY. DRFT CRANK ASSY.

HARDNESS 58-63HRC 30-35HRC 35-40HRC 25-30HRC 40-45HRC 30-36HRC 25-30HRC 40-45HRC 58-62HRC 20-24HRC 20-25HRC 25-30HRC 50-60HRC 25-30HRC 50-60HRC 25-30HRC 20-25HRC 25-30HRC 25-30HRC 25-30HRC 40-45HRC 50-55HRC 35-40HRC 35-40HRC 20-40HRC

DIFFERENTIAL S.NO. 1 2 3 4 5 6 7 8 9

PART NO. P0103005 P0406001 401019 407023 M0805007 301005 301006 407025 407026

DESCRIPTION P.T.O. COVER PLATE ( L ) P.T.O. COVER PLATE ( R ) ROCKER LINK ASSY. DRAW BAR WITHDRAWL NUT (PINION42X1.5) PLATE ASSY. ( L ) PLATE ASSY. ( R ) LOWER LINK BRACKET ( L ) LOWER LINK BRACKET ( R )

HARDNESS 180-230BHN 180-230BHN 40-45HRC 25-30HRC 25-30HRC 25-28HRC 25-28HRC 25-30HRC 25-30HRC

FRONT AXLE S.NO. 1 2 3 4 5 6 7 8 9

PART NO. 502013 502009 502007 501021 502008 501003 502002 502015 501010

DECRIPTION STEERING ARM ( L ) STEERING ARM ( R ) HUB CAP DOWEL LEEVE O-RING HOLDER PIN ( TOE HOOK ) WEAR RING ( STUB AXLE ) KING PIN PIVOT PIN

HARDNESS 210-240BHN 210-240BHN 130-180BHN 20-25BHN 20-25BHN 35-42BHN 45-50BHN 45-50HRC 25-35HRC

HARDWARE S.NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 15 16

PART NO. P0609002 301002 301003 M0806001 P0301007 104007 1003009 402025 M0811000 406034 406031 106020 401022 406025 402012

DESCRIPTION RUBBER PAD ( FLY WHEEL ) WHEEL BOLT ( REAR AXLE ) WHEEL NUT ( REAR AXLE ) STUD ( M16X1.5 ) RUBBER PAD ( FENDER ) DRAIN PLUG ( M24X1.5 ) HOSE PIPE O RING COPPER WASHER SPECIAL STUD SEALING WASHER O RING (B.P.S.) O RING (SENSOR) SEALING RING SEAL RING (ROCK SHAFT)

HARDNESS SH 65 ±5 20 - 25HRC 20 - 25HRC 20 - 25HRC SH 80 ±5 20 - 25HRC SH 60 - 65 SH 65 ±5 40 -45HRC 20 - 25HRC SH 65 ±5 SH 65 ±5 SH 65 ±5 SH 65 ±5 SH 65 ±5

GEAR BOX S.NO. 1 2 3 4 5 6 7

PART NO. P0204009 P0210004 P0210005 P0203017 207024 203010

DESCRIPTION INNER BUSH SHIFTER LEVER SHIFTER LEVER (HI - LOW) BOTTOM COVER PLATE IDLER CLUSTER PIN LOCKING PIN

207015

WITHDRAWL NUT (C.S.)

HARDNESS 180-230BHN 50-60HRC 55-60HRC 180-230BHN 58-63HRC 38-43 HRC 25-30HRC

GEAR AND SHAFTS S. NO.

PART NO.

DESCRIPTION

HARDNESS

1

P0105001

BULL GEAR

2

P0105005

BULL PINION SHAFT ( L )

3

P0105016

BULL PINION SHAFT ( R )

4

P0207020

C. M. GEAR Z-43 DUAL

5

P0102002

CONNECTING SHAFT SMALL

6

P0207023

CONNECTING SHAFT BIG

7

P0207005

CONSTNT MESH GEAR Z-45

8

P0105009

CROWN WHEEL Z-42

9

P0207019

DRIVE SHAFT Z-21

10

P0207002

FIXED GEAR Z-25

11

P0207003

FIXED GEAR Z-30

12

P0207004

FIXED GEAR Z-36

13

P0207015

IDLER CLUSTER GEAR Z-15, Z-21

14

P0205001

INPUT SHAFT Z-19

15

P0206001

INTERMEDIATE SHAFT

16

P0206008

INTERNAL GEAR (4+1)

17

P0206009

OUTPUT SHAFT

18

208009

PLANET GEAR

19

P0102006

20

206020

21

P0206002

SLIDING GEAR 34/12

22

P0206003

SLIDING GEAR Z-31

23

P0206004

SLIDING GEAR Z-24

24

101001

TAIL PINION

25

105006

CROSS

26

105007

BEVEL GEAR ( L )

PTO SHAFT (21 SPLINES) SLEEVE HI/LOW

58-63HRC 58-63HRC 58-63HRC 58-63HRC 58-63HRC 58-63HRC 58-62HRC 58-62HRC 58-62HRC 58-62HRC 58-62HRC 58-62HRC 58-63HRC 58-60HRC 58-63HRC 58-63HRC 58-63HRC 60-62HRC 52-60HRC 50-55HRC 58-63HRC 58-63HRC 58-63HRC 58-63HRC 58-63HRC 58-63HRC

27

105008

BEVEL GEAR ( R )

28

105011

BEVEL PINION

58-63HRC 58-63HRC

Project No. 2 AIM: - To implement power steering on the tractor to make the steering simpler and easier. REQUIREMENT OF THIS PROJECT 1. Larger amount of torque is required to be applied by the driver for steering of medium and heavy vehicles 2. Heavy vehicles such as Off-road trucks, fork lifts, earth moving machines, and tractors demands high steering forces. 3. Mechanical linkage between the steering wheel and the steered wheels would be more difficult and expensive in compact design vehicles.

APPLICATIONS •

Agriculture

•

Construction

•

Forklift trucks

•

Lawn and garden

•

Mini tractors

•

Municipal vehicles

COMPONENTS OF POWER STEERING 1. STEERING

WHEEL: - its diameter is 350mm [14 inch.], 3 spoke steering wheel with

knob standard and optional horn button.

2. STEERING COLUMN 

Steering columns connect the steering wheel to the steering unit.



The steering column must be supported when its length exceeds 150 mm.



The mounting of the steering column must be properly aligned so that the steering unit can return to neutral position automatically after a steering action has been completed.



The construction of the steering column must ensure that no axial or radial forces are transferred to the steering unit input shaft.

3) STEERING UNIT



It has four ports, one is connected to tank or reservoir, one is connected to pump, and remaining two is connected to steering cylinder.



It controls the flow of oil in different ports.



It is rigidly fixed with steering column.

4) PUMP 

It provides the oil to the pump.



It has two ports one is connected to steering column and other is connected to pump.



The oil used must be filtered for better working of the system.



A magnetic insert is recommended when using filters larger than 25 micron.

5. STEERING CYLINDERS:

The steering cylinder used in this power steering is double acting balanced cylinder.



Balanced cylinders are compact and eliminate differences between steering wheel turns and steering forces because of equal volumes.

6. PUMP:

The hydraulic power for the steering is provided by a Gear Pump (see diagram below).



This pump is driven by the tractor's engine via a belt and pulley.



Correct pump sizing is important in avoiding unnecessary energy consumption, or slow response to steering demand.



It supplies the required pressure to oil.

PUMP

LAYOUT OF HYDROSTATIC POWER STEERING

HOW TO SIZE THE CORRECT STEERING SYSTEM STEP 1. TOTAL STEERING TORQUE:Total steering torque, T = C.f (√B2/8 + E2 ) kgmm Where C = Load on the steered axle (in kgmm) E = King pin offset (in m) B = Tyre breadth (in m) LOAD ON THE STEERED AXLE, C = 1030 (LOAD ON FRONT STEERING) +2000 (Load of the loader)

C = 3030 kg E/B = 60/190 = .316 (WHERE B=190,E=60)

F = 0.4 (from above graph ) Where F= coefficient of friction(dimensionless).Based on 0.7

As maximum. T = 3030X0.4 √(190)2/8+(60)2 kgmm = 3030X0.4X90.07 kgmm T = 109164.13 kgmm

STEP 2. FORCE REQUIRED FOR AXLE :-

F= Mr/Rmin. Where F = Required piston rod force (in kg), Rmin. = Minimum effective radius arm (mm) F= 109164.13/100 kg F = 1091.64 kg A = F/P cm2 Where A = Pushing cylinder area (mm2), P = Steering max. pressure in bar For vehicle with a steered axle that can never be overloaded use 80% of the steering circuit relief valve setting. For moderately loaded vehicles use 60%. For vehicles that can be severely overloaded use 30%. A = 1091.64/90 = 12.13 cm2 A = 1213 mm2

STEP 3. SELECTING STEERING UNIT DISPLACEMENT:-

Before proceeding further, a decision must be made as to the number of steering wheel revolutions desired for the application to steer the axle from full one side to the. Depending on vehicle usage, this will vary, normally

2 1/2 to 5 1/2 with 4 being a good typical value.

Area of cylinder, A = Π/4[(D)2-(d)2] = Π/4[(60)2-(36)2] A= 1808 mm2 As 1808 > 1213 Therefore it is acceptable. Stroke length, S = 175 mm Volume, V = 1808X175mm3 = 316400mm3 V = 316.4 cm3 ,The volume of oil required to move cylinder rod(s) through the entire stroke. Total wheel turns, N = 3 Therefore, steering unit displacement, Cu = V/N = 316/3 cm3/rev. Cu = 105 cm3/rev. As the calculations are complete, we select the closest standard steering unit displacement (i.e. 100 cc unit) from catalog information.

STEP 4. CALCULATING REQUIRED PUMP FLOW :We select Dowty pump IP 30 28,which has discharge of 12.7 liter at 1500 rpm. At 1000 rpm its discharge will be = 12.7X1000/1500 = 8.5 liter/min. Hence at 1000 engine rpm, we shall be able to get 8.5 liter./min. which means we can steer wheel = 8.5X1000/100 = 85 rpm which is fairly ok and at 2000 rpm of engine we shall be able to steer wheel by 170 rpm.

STEERING TROUBLE SHOOTING



EXCESSIVE BACKLASH IN STEERING:- The most probable cause of this trouble is the slackness in the steering linkage due to wear of bell joints and steering.



WANDER:- When the vehicle is being driven straight, it turns slightly to one side and when the driver turns the steering to bring it back to the straight ahead, it turns slightly to the other side, thus the driver has to adjust steering constantly to keep the vehicle direction straight, the effect is called wander.



PULLING TO ONE SIDE:- Sometimes the vehicle constantly pulls towards one side.



WHEEL WOBBLE(LOW SPEED SHIMMY):- The oscillation of the front wheels at low speeds is called wobble.



HIGH SPEED SHIMMY:- The oscillation of the front wheels at high speed is called high speed shimmy.



WHEEL TRAMP:- Sometimes the front wheels of vehicle at high speeds vibrate so violently that an almost uncontrollable motion of the vehicle is caused that is called wheel tramp.



EXCESSIVE TYRE WEAR:- This is normally due to incorrect tyre pressure, excessive toe-in or toe-out.



HARD STEERING:- When the effort required for steering is more than

the normal

steering force. 

POOR RETURNABILITY:- Poor return of the steering wheel to centre may be due incorrect tyre pressure, tight or frozen steering shaft bearing, and incorrect front wheel alignment.

BENEFITS

 Minimizes steering linkage-reduces cost,

provides flexibility in design.

 Provides complete isolation of load forces from control station-provides operator comfort.  Provides continuous, unlimited control action with very low input torque.