Rolling Gear Components and Specifications

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Questions and Answers

What is the maximum allowable variation in tread circumference of wheels on the same axle?

13 mm

10 mm

5 mm

1.6 mm (correct)

Under what condition should the variation in wheel diameter between two wheels not exceed 5 mm?

When under the same coach

When on different coaches

When on the same bogie (correct)

When on the same axle

What is the maximum allowable variation in diameter under the same coach?

10 mm

5 mm

1 mm

13 mm (correct)

Which of the following dimensions does NOT apply to both 13 tonnes and 16 tonnes axles?

Axle length Signup and view all the answers

What is the smallest diameter referenced in the document?

Ø 130 Signup and view all the answers

What should the variation in wheel diameter between one pair of wheels and another exceed?

5 mm Signup and view all the answers

What is noted regarding the dimensions of wheels on the same axle?

They should not exceed a difference of 1.6 mm. Signup and view all the answers

What is the permissible limit for the distance between two wheel flanges on the same axle?

1600 mm + 2/-1 mm Signup and view all the answers

Which tool is recommended for measuring the wheel diameter accurately?

Trammel gauge with a least count of 0.1 mm Signup and view all the answers

What should be done if the wheel gauge is not within permissible limits?

Press off and then press on the wheel discs Signup and view all the answers

How accurate can a profile gauge measure flange height and thickness?

To an extent of 0.1 mm Signup and view all the answers

What is essential to do after recording the diameters of wheels?

Nominate the wheel set for necessary repairs Signup and view all the answers

What is indicated by 'THE OUTSIDE DIA.OF THE HUB'?

It denotes the diameter measurement of the hub. Signup and view all the answers

What does the abbreviation 'D' commonly stand for in mechanical terms?

Diameter Signup and view all the answers

What type of measurement does the diagram seem to emphasize?

Diameter Signup and view all the answers

If ‘10’ and ‘11’ are numerical measurements related to the hub, what do they likely represent?

The different diameter sizes available. Signup and view all the answers

Why is the outside diameter of a hub important in applications?

It impacts the mating of the hub with other parts. Signup and view all the answers

Which of the following is NOT a typical use for hub diameter measurements?

Determining hub color. Signup and view all the answers

If '%%D%%P1%%D' represents a formula related to hubs, what could 'P1' signify?

Part identifier. Signup and view all the answers

In engineering terms, what could the notation '%%' imply?

A placeholder for variable values. Signup and view all the answers

What might 'R' signify in the context of hub measurements?

Radius measurement. Signup and view all the answers

What is indicated by the center point coordinates mentioned in the content?

They are based on nominal dimensions. Signup and view all the answers

Which of the following values are most likely associated with the center point coordinates?

Mixed negative and positive values Signup and view all the answers

Why might the center point coordinates be important in arc calculations?

They indicate the position of the center. Signup and view all the answers

What does 'nominal dimensions' refer to in the context of center point coordinates?

Standardized dimensions used for reference. Signup and view all the answers

Which numerical identifier is associated with the center point coordinates in the content?

C165 Signup and view all the answers

What does the presence of both positive and zero values in the coordinates suggest?

Possible positions of the center point may vary. Signup and view all the answers

What could be a potential error in interpreting the center point coordinates?

Ignoring the nominal dimensions entirely. Signup and view all the answers

Based on the coordinates, what may be the maximum value for a Y coordinate?

+10 Signup and view all the answers

Which of the following statements is true regarding the arcs mentioned?

The arcs are based on the provided center point coordinates. Signup and view all the answers

If the center point coordinates are inaccurate, which could be a possible consequence?

Errors in the arc length and design. Signup and view all the answers

What is the maximum allowable limit when machining is necessary?

Limit +5 Signup and view all the answers

Which dimension appears to be crucial to prevent hub eccentricity?

70%%d Signup and view all the answers

What does the notation '47%%d-30'' signify in the context provided?

A percentage of a dimension Signup and view all the answers

What is the allowable tolerance range for the machining process mentioned?

+1 to -0 Signup and view all the answers

How is hub eccentricity to be prevented according to the given information?

By machining to specifications Signup and view all the answers

What does '+1' imply in the provided content?

A maximum increase Signup and view all the answers

What could be a potential consequence of not adhering to the specified limits?

Hub eccentricity could arise Signup and view all the answers

Which value represents a baseline dimension in the machining process mentioned?

47%%d-30' Signup and view all the answers

Why might machining be necessary based on the content provided?

To adjust to specified limits Signup and view all the answers

What is the significance of specifying both '+' and '-' in the tolerance limits?

Indicates acceptable deviation in both directions Signup and view all the answers

What is the significance of the '+1' limit mentioned in the machining context?

It indicates the maximum permissible diameter increase. Signup and view all the answers

Which factor is critical in preventing hub eccentricity during machining?

The outside diameter of the hub. Signup and view all the answers

What does the notation '47%%d-30'' likely refer to in mechanical measurements?

The diameter tolerance before machining. Signup and view all the answers

What does the presence of both '+1' and '-0' imply about the allowable tolerances?

Both increases and decreases are permissible within specified limits. Signup and view all the answers

Which consequence might arise from not adhering to the specified limits in hub machining?

Increased likelihood of hub wobbling. Signup and view all the answers

In mechanical tolerance measurements, what does the notation '+5' imply?

The maximum acceptable deviation above a specified measurement. Signup and view all the answers

Why is it important to determine if machining is necessary based on the limits provided?

To avoid unnecessary manufacturing costs. Signup and view all the answers

What is the significance of the specified tolerance levels in the context of rolled or forged steel?

They denote acceptable limits for dimensional variations. Signup and view all the answers

Which dimensional specification is likely to be critical for the performance of a material classified as rolled or forged steel?

The surface finish measured in Ra values. Signup and view all the answers

What does the Ra value of 0.025 indicate in the context of the material specifications?

A very smooth surface finish. Signup and view all the answers

Why might the addition of tolerance values be crucial in engineering specifications?

To ensure that parts can be interchangeable in assembly. Signup and view all the answers

What could be the consequence of exceeding the specified tolerances in machining processes?

Difficulty in component assembly. Signup and view all the answers

Which of the following best describes the 'added' references noted in the specifications?

Revisions to accommodate new testing methods. Signup and view all the answers

In the context of manufacturing tolerances, what does the notation 'MC/WA/TENDER' imply?

Specifications are subject to competitive bidding. Signup and view all the answers

Which factor is likely the least critical when determining the applicability of tolerances to forged steel?

The market price of raw materials. Signup and view all the answers

What does a tolerance of 0.1 represent in the provided measurement context?

The maximum permitted deviation from the specified dimension. Signup and view all the answers

What is the purpose of packing fresh grease during maintenance?

To ensure smooth operation by reducing friction Signup and view all the answers

What must be done to the axle boxes before fitting the front cover?

They must be cleaned and inspected Signup and view all the answers

What does a rejectable defect as per CMI-K003 imply?

It signifies serious flaws necessitating immediate replacement Signup and view all the answers

When fitting a new sealing ring, what is the expected maintenance practice?

Ensure the sealing ring is compatible with the front cover Signup and view all the answers

What critical aspect is indicated by the dimensions of the flange mentioned?

They are essential for the proper fitting of wheels Signup and view all the answers

What is the specified limit for the variation in tread diameter between two wheels on the same axle?

0.5 mm Signup and view all the answers

In the context of the document, which dimension corresponds to the total length specified?

2316 mm Signup and view all the answers

Which of the following axle box types is utilized in ICF coaches?

Spherical roller bearings Signup and view all the answers

What should be done to ensure accuracies of wheel diameters after turning?

Measure and record the diameters Signup and view all the answers

Which axle diameter is referenced for a 13 T Bogie?

φ 145 Signup and view all the answers

What is the significance of the tolerance specified as '2316 +- 0.5' in the document?

Specifies the maximum allowable deviation from the total length Signup and view all the answers

What action should be taken if the diameter difference between two wheels exceeds the allowable limit?

Replace both wheels or the axle set Signup and view all the answers

What is most likely a direct implication of having a wheel diameter variation greater than 0.5 mm?

Increased risk of derailment Signup and view all the answers

Which of the following equipment is essential for achieving precise measurements in this context?

Digital micrometer Signup and view all the answers

Which of the following is NOT a characteristic of the axle boxes mentioned in the content?

Standardization across all coach types Signup and view all the answers

What is the maximum allowable taper for an ICF axle journal with roller bearings mounted?

0.015 mm Signup and view all the answers

What should be done if an axle is found with pitting or under size journals?

Replace the axle. Signup and view all the answers

During the ultrasonic testing of axles, which of the following defects should be detected?

Internal flaws Signup and view all the answers

What is the maximum allowable ovality in an axle journal without roller bearings mounted?

0.020 mm Signup and view all the answers

What is the first step involved in the normal repair of wheel sets?

Pre-inspection of incoming wheels. Signup and view all the answers

What type of bearings are involved when the size limit for taper is checked?

Roller bearings Signup and view all the answers

What must be evaluated after cleaning axle journals for inspection?

Presence of flaws Signup and view all the answers

What is the consequence of not adhering to the specified limits for axle journals?

Potential safety hazards Signup and view all the answers

If all axle components are found acceptable, what is the next procedure?

Perform wheel profiling and servicing. Signup and view all the answers

What typically follows the cleaning and inspecting of axle boxes?

Repairs as necessary Signup and view all the answers

Study Notes

Rolling Gear

Rolling stock movement relies heavily on wheels
Complete wheel sets comprise various components, detailed in subsequent pages
Solid wheel discs are manufactured according to IRS specifications (R-19/93 Pt. II) and drawing (W/WL/1660)
Axles hold wheel discs in place
Axle boxes are affixed to axle journals
Wheel set components (mainly two): wheel discs and axle units
Wheel disc variation (across axle and bogie) shouldn't exceed 13mm
Axle diameter differences for 13t and 16t axles are similar
Railway Board (Rly. Bd.) decision: 16.25t axles are for existing 13t bogie wheel sets, but existing wheel sets can be used until replacement is needed
Components are thoroughly cleaned before pre-inspection, focusing on wheel and wheelset component condition.
Wheel gauge (distance between wheel flanges) must be 1600 mm +/- 1 mm, with measurements taken at multiple locations
Wheel diameter measured using a 0.5mm, ideally 0.1mm least count trammel gauge; tread diameter should have a maximum difference of 0.5mm between wheel pairs on an axle
Wheel profiles (as per sketch 91146) must be turned above condemning limit. Minimum diameter and shop issue size for ICF type wheels varies.
16.25t axles are now used for 13t axle bogie wheel sets

Wheel and Axle Components

Wheel discs are solid, manufactured or forged.
Wheel stamped with type (IRS W/WL-1660), manufacturer's initials, railway initials, contract number, year of manufacture, and a consecutive number
Hub diameter should be machined if necessary to prevent eccentricity
Wheel center coordinates are based on nominal dimensions
Axle journals checked for defects (flaws, pitting, ovality, taper etc.)
Axles undergo ultrasonic testing.
Axle taper shouldn't exceed 0.015/0.010 mm, and ovality should not exceed 0.015/0.020 mm
Wheels may be categorised into normal repair wheels (if within limits) or wheels requiring axle replacement (RA wheels)/solid disc replacement (RD wheels) based on various factors

Maintenance Procedures

Pre-inspection of incoming wheels, assessing component condition, involving measuring wheel components
Measurement of wheel gauge
Measurement of wheel diameter
Inspection of wheel disc/flanges as per CMI-K003 guidelines
Axle journals thoroughly cleaned to detect flaws, pitting, ovality, taper, etc, and tested for flaws via ultrasonic testing.
Wheel sets categorized prior to repair (normal, replacing axle, replacing solid discs)
Normal repair activities include inspecting incoming wheels, cleaning axle boxes, inspecting axles (ultrasonic testing), dismounting bearings (if necessary), machining profiles, cleaning/re-assembling components, and checking radial clearances.
Axle end holes checked with GO/NO-GO thread gauges
End locking plates, bolts inspected and replaced if needed
Retaining ring, felt ring, rear and front covers, axle box housing inspected for wear, damage, and proper fit
Dismounting of axle boxes and roller bearings required in certain cases.
Wheel mounting/pressing pressure within prescribed limits
Wheel pressing done carefully to maintain wheel gauge distances
Axle ends stamped with identified markings
Wheels checked at multiple points around circumference for accurate gauge

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Description

This quiz covers the essential components and specifications of rolling gears used in railway systems. Learn about wheel sets, axles, and the importance of precise measurements to ensure safety and efficiency in rail transport. Understand the guidelines set by the Railway Board concerning wheel and axle compatibility.