Bogie Frame Components and Functions Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of the bogie frame?

To transmit tractive or brake force (correct)

To lift the coach during maintenance

To provide support for the coach body

To regulate speed of the coach

Which component is NOT mentioned as part of the primary suspension?

Helical springs

Dashpots

Rubber bushings (correct)

Air springs

What are the lifting supports between the body and the bogie made of?

Composite materials

Rubber

Steel cables (correct)

Aluminum rods

How far apart are the side bearers located for trailer coaches (TC)?

1700 mm Signup and view all the answers

Which component dampens the air springs at each end of the bolster?

Hydraulic shock absorbers Signup and view all the answers

Which of the following vehicles utilizes a welded, lightweight construction for bogies?

Motor coaches (MC) Signup and view all the answers

What type of brakes is mentioned as having a direct effect on the wheel?

Tread brakes Signup and view all the answers

What happens if the clearance between the nylon rubbing plate and the steel rubbing plate exceeds 3mm during service?

It may cause excessive longitudinal oscillations. Signup and view all the answers

What is the purpose of equalising stays in the bogie assembly?

To connect the spring plank and bolster. Signup and view all the answers

Which condition requires the replacement of hydraulic shock absorbers?

In case of leaking or physical damage. Signup and view all the answers

During Periodic Overhaul (POH), what is essential for maintaining free movement of the equalising stay pins?

They must be cleaned and oiled. Signup and view all the answers

What initial clearance is required between the nylon rubbing plate and the steel rubbing plate?

1mm on each side. Signup and view all the answers

What is the primary function of the bogie (center) pivot?

To transmit acceleration and retardation forces Signup and view all the answers

How are the tyres of TC bogies secured to the wheel disc?

With glut rings Signup and view all the answers

What does the floating bolster in a TC bogie transmit between the bogie frame and coach body?

Draw and braking forces Signup and view all the answers

What is the wheel diameter for the MC bogie when new?

952mm Signup and view all the answers

Which component of the EMU coaches helps ensure positive securing of the tyres?

Locking keys Signup and view all the answers

What does the condemning limit for a new tire profile refer to?

The wear limits for various parts of the tire Signup and view all the answers

What is the wheel gauge tolerance for EMU coaches?

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

Which drawing number should be referred to for information on axle and wheel set?

ICF/MRVC/M-0-2-001 Signup and view all the answers

What is the condemning limit for the flange wear on a wheel?

As per the condemning gauge shown in I.R.CA Part IV Signup and view all the answers

What is the primary purpose of spring washers and split pins when re-using bolts?

To ensure a water-tight assembly Signup and view all the answers

Which material is used to manufacture the helical axle box springs?

Chrome vanadium, silica manganese steel Signup and view all the answers

What should be done if the surface of the lower spring seat is worn more than 0.4 mm in diameter?

It should be reclaimed Signup and view all the answers

How is the axle box guide assembly designed to ensure wheel set guidance?

By welding hollow forgings to the bogie frame Signup and view all the answers

What happens if there is an inadequate quantity of oil in the dashpot?

The lower spring seat is likely to wear Signup and view all the answers

What is the permissible variation in tread diameter for wheels of the same axle?

0.5 mm Signup and view all the answers

What is the function of the acetal/bronze bush in the axle box guides?

To facilitate lateral and longitudinal guidance Signup and view all the answers

What specification applies to tyres used in HCC bogies?

IRS Specification R-15/95 Signup and view all the answers

What is the permissible variation in tread diameter for wheels between two bogies under the same coach?

13.0 mm Signup and view all the answers

Which component is sealed with a rubber ring to maintain oil tightness?

The dashpot assembly Signup and view all the answers

What is a necessary procedure when checking axle box springs?

Measure their free height Signup and view all the answers

Which type of roller bearings are fitted on MC & HCC bogies?

Double row, self-aligning Signup and view all the answers

Which IRS specification is applicable for axles in TC bogies?

R-16/95 Signup and view all the answers

Where is the bolster positioned in relation to the air springs?

Resting on both ends Signup and view all the answers

For which purpose are axle box springs shot-peened?

To obtain higher fatigue life Signup and view all the answers

What should be checked for cracks in axle boxes particularly at the covers?

Front and back covers Signup and view all the answers

What material specifications govern the axle of MC & HCC bogies?

IRS Specification R-16/95 and R-43/92 Signup and view all the answers

Which of the following roller bearings is used for TC bogies?

22326 C/C3 Signup and view all the answers

What is a crucial precaution when maintaining axle boxes and covers?

Thorough cleaning and crack checking Signup and view all the answers

What is the primary securing method for the tyres of MC and HCC bogies?

Glut rings and 4 locking keys Signup and view all the answers

Which component does not transfer any weight through the bogie center pivot?

Center pivot Signup and view all the answers

What is the new wheel diameter for TC bogies as stated in the document?

952 mm Signup and view all the answers

What is the purpose of the anchor links in the TC bogie?

To secure the floating bolster longitudinally Signup and view all the answers

Which of the following types of wear is NOT included in the condemning limits for tire profiles?

Surface cracking Signup and view all the answers

What specifically does the floating bolster in a TC bogie transmit?

Draw and braking forces Signup and view all the answers

What should be checked if the clearance between the nylon and steel rubbing plates exceeds 3 mm?

Replacement of the rubbing plates Signup and view all the answers

Which type of roller bearings are fitted on TC bogies?

22326 C/C3 Signup and view all the answers

What material specification is applicable for axles in HCC bogies?

IRS Specification R-43/92 Signup and view all the answers

What is the purpose of the light alloy front and back covers on axle boxes?

To improve sealing Signup and view all the answers

What is the maximum permissible variation in tread diameter for wheels between two bogies under the same coach?

13.0mm Signup and view all the answers

Which drawing number should be referred to for axle roller bearing housing?

ICF/MRVC/M-0-2-002 Signup and view all the answers

Which component is particularly checked for cracks in axle boxes?

Bolt holes Signup and view all the answers

What is the purpose of the permissible variations in tread diameter at tire turning or wheel replacement?

To allow for differential wear Signup and view all the answers

What specification is applicable to the tyres used for MC bogies?

IRS Specification R-15/95 Signup and view all the answers

What should be done if the axle box springs do not meet the design requirements?

They should be replaced with new ones. Signup and view all the answers

What action should be taken if the surface of the lower spring seat is scored or worn?

Reclaim the seat if worn more than 0.4 mm. Signup and view all the answers

Which component guarantees the wheel sets are guided in both lateral and longitudinal directions?

Axle box guides Signup and view all the answers

What is the result of inadequate oil in the dashpot regarding the lower spring seat?

It may wear down due to lack of lubrication. Signup and view all the answers

What is the primary function of shot-peening axle box springs?

To improve fatigue life. Signup and view all the answers

What feature ensures the axle box guide assemblies remain oil-tight?

The use of rubber rings. Signup and view all the answers

What categories should axle box springs be grouped into according to RDSO Technical Pamphlet No.C-8419?

Three categories based on user manual specifications. Signup and view all the answers

Which of the following is NOT a recommended examination for bolts before re-use?

Evaluating color consistency. Signup and view all the answers

Where does the guide bush of the dashpot move up and down within the axle box?

In the lower spring seat. Signup and view all the answers

What is crucial for ensuring the functional integrity of the bolt covers and axle box housing?

Ensuring they are locked by split pins and spring washers. Signup and view all the answers

What is the maximum allowable clearance between the nylon rubbing plate and the steel rubbing plate during service?

3mm Signup and view all the answers

What maintenance action is specifically required for the equalising stay pins during POH?

Remove, clean, and oil them Signup and view all the answers

What is the main issue that leads to the replacement of hydraulic shock absorbers?

Physical damage or leakage Signup and view all the answers

What should be done during POH to maintain the initial clearance around the nylon rubbing plate?

Adjust with steel packings of suitable thickness Signup and view all the answers

How should the hydraulic shock absorbers be maintained during regular service?

They require no attention between POHs Signup and view all the answers

What consequence may occur if the clearance exceeds the specified limit during service?

Excessive longitudinal oscillations Signup and view all the answers

What should be ensured for the free movement of pins in the equalising stays?

They should be cleaned and greased Signup and view all the answers

Which part is considered to cushion the bolster in the MC and HCC bogie?

Nylon rubbing plate Signup and view all the answers

What feature of equalising stays is intended to prevent lateral thrust?

Pin jointed design Signup and view all the answers

What is the primary purpose of steel packings during POH?

To maintain gap clearance Signup and view all the answers

What determines the maximum wear limit for the hard ground plate in side bearers?

1.5 mm of wear Signup and view all the answers

Which function does the centre pivot of the trailer coach primarily serve?

Transmits tractive and braking forces Signup and view all the answers

Which component requires rounding off sharp edges to maintain functionality?

Spherical bronze wearing piece Signup and view all the answers

In the context of side bearers, what is the purpose of the oil well cover?

To prevent ingress of dust Signup and view all the answers

What is the required oil quantity for each side bearer in the specified maintenance?

2.5 litres Signup and view all the answers

Study Notes

Bogie & Under Gears

Bogie frames are welded with two longitudinal girders, a crossbar, and two frame ends. Tractive and brake forces are transmitted via a bogie pin.
Frame ends support brake cylinders and rigging. Tread brakes directly affect the wheels.
Four steel cables connect the body and bogie as lifting supports.
Primary suspension uses helical springs in parallel with dashpots, mounted on a floating bogie bolster. The bolster rests on air springs which in turn are supported by a spring plank. Shock absorbers dampen the air springs.
Secondary air suspension, wheel and axle, and hydraulic shock absorbers of AC EMU, DC EMU and AC-DC EMU bogies refer to CMI-K001 (April 2000) and amendment slip no. 1 (Feb. 2007) for maintenance. Air suspension maintenance is detailed in CMI-9802 (Rev.2), February 2008, issued by Carriage Directorate, RDSO, Lucknow.
Bogies in motor coaches (MC), high carrying capacity coaches (HCC), and trailer coaches (TC) are lightweight and welded. Axles are fitted with self-aligning roller bearings in cast steel axle boxes, rigidly guided by telescopic dashpot and axle box guides.

Wheel & Axle

EMU coaches have composite wheels with rolled steel centres and renewable tyres.
On TC bogies, tyres are fastened to the wheel disc with glut rings. MC/ HCC bogies use glut rings and four additional locking keys.
Drawings for bogie general arrangement, frame arrangement, axles, and wheel sets are provided in annexures.

Tyre Profile

Tyre profiles follow ROSO Sketch No. 91146, with specified condemning limits for various types of flange wear and tread wear.
Wheel gauge tolerance is +2/-1 mm.
Wheel diameters for MC, TC, and HCC bogies are specified (952mm for new, 877mm, 857mm, and 865mm as condemning limits). Sizes are also noted for last shop issue.

Permissible Variation in Wheel Tread Diameter

Variations in wheel diameters differ based on axles, bogies, and coach types. Permissible variations are noted regarding clearances, which are necessary for tyre changes and wheel replacement. Values for these variations are noted.

Material Specification for Wheel and Axle

Tyre specifications are defined by IRS Specification R-15/95.
Axle specifications include IRS Specification R-16/95 for TC bogies and IRS Specification R-43/92 for MC and HCC bogies.

Roller Bearings

MC and HCC bogies use direct mounted, double row, self-aligning roller bearings (No. 22328 C/C3).
TC bogies use similar bearings (No. 22326 C/C3). Details are provided in drawings from the annexure.

Axle Box Housing

Cast steel axle boxes house double-row self-aligning spherical roller bearings. Alloy front and back covers are attached by bolts.
Cracks in the cover holes need to be checked. Bolts and threads must be examined before reuse. Covers require tightening using spring washers and split pins for ensuring airtight assembly.
Protecting the bearings from dust and moisture is essential.

Axle Box Springs

Axle springs are helical, constructed from centerless ground chrome vanadium, silica manganese steel.
Springs are shot-peened to increase fatigue life. Crack inspection and free height measurement are vital for compliance with design requirements.
Spring grouping protocols are determined by RDSO Technical Pamphlet No. C-8419, Revision 1.

Lower Spring Seat

Lower spring seats on axle box wings, where guide bushes move, are normally wear resistant.
The maximum allowable wear is 0.4 mm in diameter, or the surface cannot be scored or damaged. Replace them if these issues are present. Any cracks need to be examined before re-use.

Dashpots & Axle Guides

Axle guides are accurately machined hollow forgings welded to the bogie frame, ensuring rigidity in guiding lateral and longitudinal axle movements.
Acetal/ bronze bushes are fitted on the lower end of the guides. The assembled unit is oil-filled and sealed to prevent oil leakage and maintain oil tightness.
Coach types determine topping-up procedures for oil.

Equalizing Stays

Equalizing stays connect the spring plank and bolster with pin joints to prevent lateral thrust on the bolster springs.
Pins should be cleaned, oiled, and checked for proper rotation before reassembly.
Washers and split pins are used to secure pins and prevent them from falling out.

Centre Pivot

The centre pivot arrangement is diagrammed and designed for tractive and braking forces.
The body bolster of the under-frame has a bush that accommodates the centre pivot pin.
Wear is managed by upper and lower bushes between the centre pivot pin and the bogie bolster.

Centre Pivot (Trailer Coach)

Centre pivot arrangement in trailer coaches is not intended for vertical load transmission; it only transmits tractive and braking forces. Specific details for this style are noted.

Side Bearers

Side bearers are hard-wearing ground steel plates immersed in an oil bath.
A floating bronze wearing piece with a self-aligning spherical top surface supports the carriage body.
An oil well cover protects the assembly, while oil-filling nipples allow convenient lubrication without coach lifting. Required oil amounts per side bearer are 2.5 liters. Recommended oil types are Servoline-68, Yantrol-68, and Bharat Univol-68.

Anchor Links

Anchor links are to be inspected for any cracks at welds and silent bloc rubber deterioration, including fretting on the edges.
Links should be tested thoroughly before reuse. To avoid pre-loading links during installation ensure that they can be positioned without force.

Hanger and Hanger Blocks

Hanger and hanger blocks must be thoroughly cleaned, inspected for cracks, and examined for wear or damage.

Bogie Brake Gear

Maximum radial clearance between brake gear pins and bushes is 1 mm.
Brake blocks should be replaced when thickness falls to 16 mm.
An adjusting palm pull rod with holes facilitates slack adjustment. Procedures are noted for adjusting the rod and replacing brake blocks.
Drawings for the bogie brake gear assembly are noted.

Buffing & Draw Gear

EMU/MEMU coaches use semi-permanent/semi-automatic Schaku couplers, maintained according to manufacturer's instructions.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the components and functions of the bogie frame used in vehicles. This quiz covers aspects such as suspension, equalizing stays, and maintenance practices. Perfect for students studying vehicle engineering and design.