EXs and Tutorials.pptx

Veh Systems-Ch-1:Running Gears Col (Retd) GC Mishra

1

Running GearExercise-1

A tracked vehicle with gross weight of 50 tons has following specifications:-Number of bogie stations=6Track preliminary tension=30 kNAngle of inclinations front track=450rear track=300

Calculate the total loads on the front and rear road wheels.Assume, Weight of the tank is uniformly distributed between all the

road wheels. Inclination angle of the top run of the track≈0


2

Exercise-1:solutionTank weight Gs=50 tonX9.91=490.5 kN; No. of bogie stations=6T, track preliminary tension=30 kNAngle of inclination of track, front, βf=450; βr=300

Wt. of tank is uniformly distributed therefore, Rf=Rr =Gs/12=490.5/12=40.84 kNInclination angle of top run, ν=0, therefore Rj is same for all wheels.

kNSinkNTSinP

kNSinkNTSinP

rpr

fpf

53.152

30302

22

232

45302

22

0)(

0)(


3

Exercise-1:solution..

kN

TTRP

kN

TTRP

rrrr

ffff

85.55)]30cos1(30[30sin3084.40

)]cos1([sin

67.62)]45cos1(30[45sin3084.40

)]cos1([sin

22

22

22

22

Pf

T.sinβf

T.(1-cosβf)

Rf


4

Tutorial-1A tracked vehicle with gross weight of 36 tons has following specifications:-• Number of bogie stations=5• Track preliminary tension=25 kN• Angle of inclinations

•front track=450

•rear track=300

Calculate

a. Total Reaction ∑Rj transmitted to the shafts of all the road wheels from the ground.

b. The total loads on the front and rear road wheels.

Assume, Weight of the tank is uniformly distributed between all the road wheels.

Inclination angle of the top run of the track≈80


5

Tutorial-2A tracked vehicle with gross weight of 36 tons Tank T-55) has following specifications:- Number of bogie stations =5 Track preliminary tension =30 kN Angle of inclinations

front track =450

rear track =300

Radius of: Driving sprocket, rds=346 mm Idler wheel, riw=255 mm

Centre to centre distance; Driving sprocket to road wheel, Zds=210 mm Idler wheel to road wheel, Ziw=rds=380 mm

Overall length, L0=6.2 m Length on ground, L=3.84 m Displacement of cg to the front, ρ=0.3 mCalculate, a. Inclination angle of the top run of the trackb. Total Reaction ∑Rj transmitted to the shafts of all the road wheels from the

ground.c. The total loads on the front and rear road wheels.

MV-6141-Ch-2-3-Tk track Mech-sprockets-Idlers Prof (Col) GC Mishra, Retd

6

Tank track; Sprockets-Exercise

Design the sprocket of an MBT with following specifications:- Weight =40 ton Track pitch =0.143 m

Take following basic data for multi-pitch meshing (td.s=ttr):-

Maximum permissible increment of track pitch, Δttr=0.15 ttr

Radius of the track link cogs, rcog=0.17ttr

Number of teeth on the sprocket, Zd.s=14 Radius of curvature of the teeth, Rt=0.3 m Pressure angle of the teeth θp=400

Use following data:-Sp. calculated necessary adhesion track force of the faster moving track,

fnec.ad=0.6Efficiency of the track drive, ηtr.dr=0.95Permissible bending stress for the teeth, σ=500 MPaModulus of elongation of steel E=206000 MPa

Calculate the Height, base width and depth of the teeth (assume width=depth)

Also, check your calculated figures for the contact bearing stress σc(Permissible σc=2950 MPa for gear rims made of steel with surface heat treatment upto 50 HRC.


7

Tutorial

The sprocket of an MBT weighing 40 ton, has to be designed for multi-pitch meshing (td.s=ttr). It has a track pitch of 0.14 m.

Calculate the Height, base width and depth of the teeth (assume width=twice the depth)

Also, check your calculated figures for the contact bearing stress σc(Permissible σc=2950 MPa for gear rims made of steel with surface heat treatment upto 50 HRC.

Take following basic data for :-

• Maximum permissible increment of track pitch, Δttr=0.15 ttr

• Radius of the track link cogs, rcog=0.16ttr

• Number of teeth on the sprocket, Zd.s=14• Radius of curvature of the teeth, Rt=0.3 m• Pressure angle of the teeth θp=400

Use following data:-Sp. calculated necessary adhesion track force of the faster moving track,

fnec.ad=0.6Efficiency of the track drive, ηtr.dr=0.95Permissible bending stress for the teeth, σ=500 MPaModulus of elongation of steel E=206000 MPa


8

Exercise

Design the track link of an MBT with following specifications:-

• Weight=43 ton• Track width=580 mm• Total number of links of a new tank=96• Number of ears/grooves on the embracing side=4• Sp. calculated necessary adhesion track force fnec.ad=0.6• Average shearing stress (ζ) of the ears not to exceed 65 MPa• Average breaking stress (σ) of the ears not to exceed 50 MPa

Calculate the following:-

• Diameter of the track pins.• Width of each ear of the embracing and the embraced side of the links

(take bi=bi’).• Outer and inner radius of the ears.


9

Tutorial

Calculate the overall dimensions of the track link of an MBT with following specifications:-

• Weight=440 kN• Track width=575 mm• Total number of links of a new tank=96• Number of ears/grooves on the embracing side=4• Sp. calculated necessary adhesion track force fnec.ad=0.6• Average shearing stress (ζ) of the ears not to exceed 60 MPa• Average breaking stress (σ) of the ears not to exceed 50 MPa

Calculate the following:-

• Diameter of the track pins.• Width of each ear of the embracing and the embraced side of the links

(take bi=bi’).• Outer and inner radius of the ears.

MV-6141-Ch-4-Veh Suspension-torsion bar Prof (Col) GC Mishra, Retd

10

Torsion BarExercise-1

A torsion bar suspension is to be designed To support a maximum static load of 3500 N at the end of a

lever arm 250 mm long.The deflection of the lever above the horizontal is to be 300 with

a total angle of deflection 900.Assume a safe allowable stress of 785 MPa.Modulus of rigidity, G = 73575 MPa.

Calculate:-

1. Diameter of the torsion bar.

2. The effective length of the tension bar.

3. The load rate (spring rate) of the bar.


11

Tutorial -1

A torsion bar suspension is to be designed for an MBT of weight 43.8 tons with 12 bogie stations.

Lever arm 300 mm long.

The deflection of the lever above the horizontal is to be 300 with a total angle of deflection 900.

Assume a safe allowable stress of 800 MPa.

Modulus of rigidity, G = 74000 MPa.

Calculate:-


2. The effective length of the tension bar.

3. The load rate (spring rate) of the bar.


12

Tutorial -2

A torsion bar suspension is to be designed for an MBT of weight 45 tons with 12 bogie stations.

• Lever arm 300 mm long.

• Effective length of the torsion bar not to exceed 3 m.

• The deflection of the lever above the horizontal is to be 300.

• Assume a safe allowable stress of 800 MPa.

• Modulus of rigidity, G = 74000 MPa.

Calculate:-


2. Total angle of deflection of the tension bar.

Documents

EXs and Tutorials.pptx