Sumit U. Choudhari, Rajat R. Badwaik,Satish R.
Kavre, Mangesh T. Pardi, Pawan S. Barange, Sanjay G. AchreMechanical Department, NagpurUniversity Abstract— Wheel deformation is one of the major failures in Indian Railways.In this paper we study the most efficient methods of wheel maintenance forinteraction of dynamic forces and rate of wear between rail and wheel.
The erosionof wheel influence the dynamic characteristics of the vehicle and the dynamicforce strike on the wheel flange by the rail line results in derailment. The erosionof wheel mostly depends on abrasion and inappropriate maintenance on board. Thereforethe wheel should take into consideration as the major derailment happens due towheel deformation of the ride. When brake applies on ghat sections and downgradients due to continuous application and releasing of brakes, defects suchas pitting mark, wheel shelling and heat check occurs. Keywords— Derailment, Pitting mark,wheel shelling, wheel deformation, wheel failures, Indian Railways.I.
IntroductionWheels are the important component ofevery vehicle, to make vehicle more efficient and comfortable, wheel plays animportant role. Therefore the maintenance should be proper and defects shouldbe minimised for generating optimum output. Most of the population in Indiatravel through railways. Hence the travelling vehicle should have minimumfailures, so that people should not face troubles and causalities. For this,vehicle mainly wheels should be properly maintained and have lesser defects init.
After 2016 India stared using LHB (Linke Holfmann Busch)coaches which are lesser in weight and have designed to run at high speed. Asthe speed is more the application of brake should work efficiently and allcomes to wheel to stop the train at right time. This deals more damage to thewheels. As wheel failures already a huge problem in railways hence we must haveto focus on wheel conditions and its failures. II. wheel DefectsWheel is the most dynamic part inrailways, also make vital role in safe travelling. In railways wheel make twoimportant functions i.e.
bears the weight as well as guiding the wagon hencedefects in wheel leads to a serious damage. And mainly defects are found inwheel profile. Some of the defects are as followsI) Sharp Flange- When radius offlange is wear up to 5mm. This defect is known as sharp flange. Due to continuoushitting of flange the inclination of flange reduces and can cause derailment.II) Deep Flange- If depth in flangeis wear up to 35mm, this defect in wheel is known as deep flange, this candamage to fish plates, fish bolts, and check bolt also a cause of derailmentmainly at check blocks.III) Hollow tyre- because of erosion on the wheel tread causedby inappropriate brake block material composition, the the wheel tread wearsout and forms the arc due to inclination given on the wheel.IV) Thin tyre- Generally the thin tyres recognisedby thickness of the tyre, may reduce up to 25mm.
V) Thin flange- in this type thethickness of flange minimizes up to 16mm. The thickness of flange must becalculated at the 13mm from the tip.III. how does it occur? 1) During ghat sections and down gradients continues application andreleasing of brakes should be done, so that vehicle should not attends highspeed. Due to continues application the temperature of the wheel increases andbecomes warms, and cools due to surrounding temperature, due to continuous ofthis treatment material becomes hard and wear out some chips called as shellingof wheel, heat check forming of wheel tread.2) If brakes not fully released by loco pilot from engine, or defect inbreak equipment some of wheel defects occurs such as flat tyre, metaldeposition on wheel tread. 3) Inertial drag due to sudden movement of the train at start can causeflat tyre.
4) Brake block composition also develops the defects in wheels. 5) Brake block boundaries fail and break block back plate touching tothe wheel trend also develop grove in wheel trend. IV.
parameters for defect allowance Type Of Defect Designed Parameter Allowed Limit Sharp Flange 14.5 mm Less than 5 mm Thin Flange 28.5 mm Less than 16mm Less radius at root of flange 16 mm-IRS 14 mm-WWP Less than 13 mm Hollow Tyre —— 5 mm or above Deep Flange 28.5 mm More than 35mm Thin Tyre ——- Since no tired wheel, dia of the wheel is the criteria. Flat Tyre ——- 50 mm or more-Coaching 60 mm or more –Goods Table 1.
– Allowed limit parameters with typeof defect V. Remedies I. While application of brakesfrom train engine sufficient time to be used for releasing the brakes.II. Brake component i.e.
, check properly during maintenance and follow time to time oiling andmaintained piston stroke.III. Maintained brake poweraccording to wheel diameter.IV. Standard brake component to beused in braking system.
V. Specify breaking block to beused during maintenance and time to time replace before allowed limit.VI.
No break pressure leakage allowin brake power pipe, joints, air hoes, D.V., B.S.Y.L.
and antilock.VII. Maintained B.P. and F.
P. pressurein prescribed limit i.e. 5kg/cm2 in engine and rear brake is 4.8 kg/cm2and F.P. in engine 6 kg/cm2 and rear brake valve 5.8 kg/cm2VIII.
Time to time maintenance scheduleshould be carried out.IX. Check wheel in schedule maintenanceafter applying gauge.X. Before start the train checkbreak power properly released throughout the train.
VI. ConclusionDefects present in wheel may causeunwanted noise and vibrations which are uncomfortable to the passengers, morepower would be required to carry the defected wheel. Defected wheel may causeof derailments, excidents also can cause damages to the other part of thewagon. Major derailments occurs in Indian Railways to avoid such type ofproblems prescribed remidies should be take into consideration.