Hyd Damper g3 m3d

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GOVERNMENT OF INDIA MINISTRY OF RAILWAYS

SPECIFICATION FOR HYDRAULIC DAMPERS OF WDG3A,

WDM3D (WITH EQUALISER & COMPENSATING MECHANISM) AND

WDM3A (WITH A.T.H.S BOGIES) LOCOMOTIVES

No. MP.0.49.00.16 (Revision - 00)

March 2009

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RESEARCH DESIGNS & STANDARDS ORGANISATION LUCKNOW - 226 011

Cost (Rs).………

R.D.S.O

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GOVERNMENT OF INDIA MINISTRY OF RAILWAYS


WDM3D (WITH EQUALISER & COMPENSATING MECHANISM) AND

WDM3A (WITH A.T.H.S BOGIES) LOCOMOTIVES

No. MP.0.49.00.16 (Revision - 00)

March 2009

vuqla/kku vfHkdYi vkSj ekud laxBu y[kuÅ&226 011

RESEARCH DESIGNS & STANDARDS ORGANISATION LUCKNOW - 226 011

Cost (Rs).………

Prepared By Checked By Approved By

S.P.Govil Asstt. Design Engineer (MP)

Naresh Kumar Director (MP/VDG)

S.Mani Executive Director(MP)

R.D.S.O

Specification for Hydraulic Dampers of WDG3A, WDM3D (With equalizer & compensating mech.) & WDM3A (with ATHS bogies) Locomotives

Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09

CONTENTS

Sr. Description Page

1. Scope 1

2. Deviation(s) 1

3. Drawings 1

4. Damper Design Requirements 1

5. Damper Performance Description 2

6. Endurance Testing of Hydraulic Dampers 4

7. Test Results 4

8. Warranty 4

9. Marking 5

10. Packing 5

11. Field Trials 5

Annexure I Endurance testing procedure for hydraulic dampers of WDG3A, WDM3D (with equaliser & compensating mechanism) and WDM3A / WDM3C (with A.T.H.S bogies) locomotives

i

Annexure II Quality Assurance & Guarantee Certificate viii


Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. 1


WDM3D (WITH EQUALISER & COMPENSATING MECHANISM) AND WDM3A (WITH A.T.H.S BOGIES) LOCOMOTIVES

1. SCOPE This document covers the technical specifications for vertical & lateral hydraulic dampers for use in WDG3A, WDM3D (With equalizer & compensating mechanism) & WDM3A (with A.T.H.S bogies) locomotives. However, this specification does not include all the necessary provisions required for a supply contract.

2. DEVIATION(s) If deviations from original design, dimensions etc. are desired by the supplier, specific proposals with reasons shall be submitted to the purchaser. Commencement of manufacture shall not be done till the purchaser grants clear authorization for acceptance of the deviation(s). In case of contradiction between this specification and the relevant RDSO drawing(s) or if any special requirements are given in these drawing(s), the stipulations in the drawing(s) shall override this specification.

3. DRAWINGS The document shall be applicable to dampers to Drg No. SK.VL - 295, SK.VL - 328, SK.VL- 471 & SK.VL - 527.

4. DAMPER DESIGN REQUIREMENTS Hydraulic dampers should meet the following design requirements:

4.1 End mountings / Silent blocks / Spheribloc: End mounting with better quality of rubber (Shore hardness between 60 to 70 Shore A) should be provided. Arrangement to fit dust caps should be such that it does not get loose or detached during locomotive operation.

4.2 Clearance between mounting bolts & damper eye: Strict adherence to specified tolerance has been recommended between damper eye and its mounting bolt to avoid impact loading during operation.

4.3 Installation of dampers: The nut & bolts for the fitment of damper in position should be provided by the damper supplier along with the damper to avoid any play in the fitment which can control the failure of silent blocks/ mounting bolts. The OEM should indicate the torque value for tightening the damper mounting bolts (hexagonal head bolts) to mount dampers on locomotive. Latest locking aids like disc lock washers should be supplied along with dampers to prevent loosening of mounting bolts due to vibrations during locomotive operation.

4.4 Provision of oil seals: An oil seal along with a special sealing ring has been recommended in lock ring (cover) should be to avoid ingress of dust inside the damper. These seals should provide less friction, should be capable of withstanding higher pressure and should be wear resistant should to achieve higher working life and reliability.

4.5 Improvement in dust cover and casing tube: Dust covers break from its joint with the Piston Rod Eye. Extra strengthening of joint and use of seamless tubes for protection cover and casing tubes has been recommended to increase the life of dampers.



4.6 Improvement in surface finish of cylinder & piston rod: A superfine finish of these sub-components will help controlling their excessive wear. OEMs have been recommended to maintain a surface finish of 10 to 35 µm or better for cylinder after honing and 0.1 to 0.3 µm for piston rod after hard chrome to achieve the desired results.

4.7 Positive locking of Piston and Piston rod: Due to higher forces encountered at higher operating speeds, there is a possibility that piston could rotate and free itself from piston rod. Therefore, positive locking of piston with piston ring has been recommended like use of circlip, nylock nuts etc.

4.8 Installation height of dampers: Installation height of dampers should be maintained to the specified limits such that the designed stroke length is available in tensile and compression stroke and the piston does not reach the extreme positions during locomotive run. This will help in protecting damper from excessive/ shock loading.

4.9 Improvements in damping oil: OEMs have been advised to use damping oil such that they do not lose their viscosity during service with temperature variation to an extent, which can affect damping characteristics of damper.

4.10 Rubber components: The rubber components being used inside the damper are exposed to oil. Hence, the rubber being used for these components should have good resistance to oil absorption, sufficient to sustain a minimum of 48 months life.

4.11 Internal design: The internal mechanism with a provision of discharge valve so that, in any odd situation and hyper characteristics of the force of oil beyond a prescribed limit may discharge automatically to prevent the failure of the damping system.

4.12 Sealing arrangement: One of the major causes of damper failures is ingress of dust along with piston rod. Specific measures to guard against dust have been recommended like use of sealing arrangements with better wiping properties, provision of additional dust lip etc.

4.13 Cleanliness of damper components: The cleanness of critical damper parts has to be of high standards. Ultra-sonic cleaning of critical parts is desirable for long life of dampers. Any dust or burrs will damage the seals, surfaces and properties of oil. Cleaning of other parts to be done by machine wash.

4.14 Leak test of sub-assemblies: Internal leakages in the damper can deteriorate in service leading to loss of damping forces. Hence, leak test of sub-assemblies have been introduced before final assembly.

5. DAMPER PERFORMANCE DESCRIPTION 5.1 OPERATIONAL REQUIREMENTS A. Service Conditions

.1 Service Intervals The service interval of the damper & the maximum admissible percent deterioration of damping characteristics at the end of service interval in comparison to the nominal damping characteristic shall be as follows:

Sr. Conditions Requirements 1. Service interval of the damper 10,00,000 kms or 4 years 2. The maximum admissible percent deterioration of the F-

V characteristic at the end of service interval in comparison to the nominal F- V characteristic

Deterioration shall not be more than 25 %



.2 Operational Environment Conditions The damper shall be resistant to the following operating environmental conditions to which it may be exposed during service: − Projection of ballast − Exposure to oil or petroleum − Wind, rain, snow, cold dust, sand storms − Saline spray − Washing plant agent (both acids & alkalis) − 100% humidity − Exposure to organic waste, sand, brake & ferric oxide dust (abrasion of wheels, brake blocks

and tracks) .3 Operating Temperatures The damper is required to function safely up to operating temperature of 70º C. After operating to extremes, the damper shall be required to fully recover its functionality. Furthermore, the damper shall not display any fluid leaks or any signs of failure or cracking in the damper components.

B. Storage Temperatures ( Ts,min ; Ts,max ) The damper shall withstand the following temperature range during transport or storage:

Sr. Conditions Requirements 1. Minimum temperature to withstand during transport or storage Ts, min - 10º C 2. Maximum temperature to withstand during transport or storage Ts, max + 70º C

C. Other Conditions: Vibrational exposure / Effect of oscillation frequency on overall damping characteristic In order to clarify the damper vibrational exposure, the supplier’s (OEM’s) “Damper Performance Description” shall specify location of damper application in vehicle & resonant sources frequency. The dampers should satisfactorily withstand the vibration levels at the intended application in primary / secondary suspension stages of locomotive bogie.

5.2 PHYSICAL REQUIREMENTS A. Strength: The construction of Hydraulic Damper shall be such as to withstand the static

compressive axial load of 3 tonnes when fully closed and a tensile load of 3 tonnes when fully extended respectively without any failure, damage or permanent change in damping characteristic or reduction in service interval.

B. Dimensional Parameters: Various dimensional parameters of the damper shall be as per the relevant RDSO Drawing.

C. Adjustability: The damper capacity shall be adjustable and the adjustment shall be easy to perform. It shall be clearly indicated if any special tools and devices are required. The maintenance instructions for the damper shall cover the procedure to perform such adjustments.

D. Surface Protection: All the parts of the damper in contact with the ambient air shall be protected from corrosion. The protection can be ensured either by the nature of materials used or by suitable painting / surface treatments. The following requirements for the damper painting and other anti-corrosion surface protections (in particular, the stem surface treatment or plating) shall be maintained:

Painting Parameters Requirements Colour: RAL number RAL 7012 Minimum dry film thickness according to ISO 2808 ≥ 120 μ Adhesion ISO 2409 or EN 24624

Rubber parts shall not be painted. Otherwise, the supplier has to produce test results or return



from service experience data demonstrating that painting process doesn’t alter rubber mechanical characteristics for the whole damper service life.

E. Damper Oil: The details of damper oil including type, viscosity and amount of the damper oil shall be provided by the supplier.

F. Leakage: The damper shall operate without excessive loss of oil throughout its operating life. Oil loss is excessive when there is visible evidence of accumulation of oil in the form of drip on the body of the damper. Once leakage seems to be present in service, the damper has to be cleaned from oil & dust and shall be checked after one week or 1000 km. If oil is again present on the damper and/ or oil is bonded in an area of 100 cm2 of dust, the damper is classified as leaking.

G. Noise: When determined as being necessary, the damper shall provide no noise during work.

5.3 FUNCTIONAL REQUIREMENTS A. Orientation: The range of various damper angular positions during fitment and operation shall be

as per the relevant RDSO drawing. .1 Overall Damping Characteristics The overall damping forces on the compression and extension strokes of the damper, taken separately, shall be within the ± 10% tolerances of capacity as specified in the drawing(s). The Hydraulic Damper shall be assembled in such a manner that the damping shall be uniform throughout the stroke i.e. the damping characteristics shall not have any sudden deviation or changes throughout the stroke. The stipulated tolerances and requirements shall apply at all points within the required working stroke of the Hydraulic Damper. .2 Force - Displacement Characteristic (Damping characteristics) The shape of the Force - Displacement curve or Hysteresis Cycle shall be regular and symmetrical, and in particular shall be free from flex, local Vibrational phenomena and jumps / sudden change in the shape of the curve. .3 Priming The damper must not lose priming during service or after storage or transport.

6. ENDURANCE TESTING OF HYDRAULIC DAMPERS Endurance Testing of Hydraulic Damper should be done during the initial approval of a supplier as RDSO approved source for supply of Hydraulic Dampers to Railways/ PUs. It should subsequently be done every alternate year for the first lot of the Hydraulic Damper to be supplied by the supplier. Endurance testing of newly designed Hydraulic Damper shall be done if desired by the purchaser. Endurance Testing of Hydraulic Dampers shall be undertaken as per the “Endurance Testing Procedure” enclosed in the Annexure I.

7. TEST RESULTS The supplier shall submit internal test results in support of various performance characteristics/ endurance test, duly signed by supplier or his authorized representative.

8. WARRANTY The supplier shall furnish a guarantee that each new hydraulic damper supplied, shall function satisfactorily without attention and in accordance with the requirements of this document for 10,00,000



kms of service running on a vehicle or for 4 years from the date of fitment to a vehicle, whichever is earlier. A format of the certificate is given at Annexure - II. Hydraulic Damper found to be defective after delivery within the warranty period will be returned to the manufacturer for replacement, not withstanding that they may have passed the relevant tests and have been accepted by the Inspecting Agency.

9. MARKING Marking (identification) plate should be of ‘Aluminum’ and should be fixed by ‘Aluminum’ rivets on the damper. It shall be legibly marked with: a. Manufacturer’s name or Code b. Serial No. c. Type of Damper d. Rated Capacity e. Month & Year of manufacture f. “IR” g. RDSO drawing No.

10. PACKING The manufacturer shall ensure that Hydraulic Dampers are suitably packed in polyethylene covers using suitable cartons to prevent ingress of foreign matter and damage during handling and storage.

11. FIELD TRIALS Before approval in Part II in RDSO vendor directory, the field performance for a period of one year

shall be monitored.


Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. i

Annexure I

ENDURANCE TESTING PROCEDURE FOR HYDRAULIC DAMPERS OF WDG3A, WDM3D (WITH EQUALISER & COMPENSATING MECHANISM) AND

WDM3A / WDM3C (WITH A.T.H.S BOGIES) LOCOMOTIVES

1. BACKGROUND The purpose of endurance testing of hydraulic damper is to check its suitability for field application

under simulated operating conditions in test laboratory in a limited time frame. It is used as a criterion to ascertain the expected service life. The fatigue test shall be carried out on dampers as per the procedure given below.

2. TEST MACHINE

The hydraulic dampers can be tested as single damper or in a fixture together with other hydraulic dampers. The fixture should be designed in such a way that both ends of the damper remain parallel and perpendicular to the loading direction. Besides, suitable arrangements for damper cooling during endurance testing should be available to ensure that damper oil temperature is controlled within the specified range. The test setup should allow measuring height, load and stroke simultaneously. The machine should be capable to apply the desired forces at specified frequency and speed. It should also have facility to seal the Fatigue Cycle Counters and dampers being tested. The test machine should be properly calibrated. Pictorial view of a typical endurance testing machine is given below.

A. SAMPLE QUANTITY

Three nos. of samples manufactured as per the relevant RDSO drawing should be randomly selected from the damper lot for strength and endurance test.

Typical Endurance Testing Setup for Locomotive Hydraulic Dampers


Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. ii

4. TEST PREPARATION The inspection authority shall witness the calibration of testing machine and ascertain under test conditions, various parameters to be measured in the sample dampers being tested. Visually examine the test samples for soundness.

5. DAMPER TESTING A. STRENGTH/PERFORMANCE TEST

.1 Prior to endurance testing, each selected hydraulic damper shall be compressed to its fully closed position and then extended to its maximum stroke (expanded) position at damper temperature range of 20 ± 2 ºC inclusive. The construction of hydraulic damper and mountings shall be such as to withstand the static compressive axial load of 3 tonnes when fully closed and a tensile load of 3 tonnes when fully extended. No component of damper should suffer damage or permanent distortion. Besides, no signs of oil leakage should be visible. The damping force measurements should be done as per Proforma placed at Annexure IA. The measured damping forces should lie within the permissible limits as per the relevant RDSO drawing under various testing conditions prescribed in the Annexure I. All the three samples should pass the strength/performance test. If any of the samples fail this test, double the failed quantity shall be selected and subjected to this test. All of these samples should pass the stipulated criteria failing which the whole damper lot shall be rejected.

.2 Each hydraulic damper shall be primed prior to testing to ensure that all the air is brought into the correct chamber of the damper and then handled in such a way that the primed condition is maintained during testing.

B. FORCE - DISPLACEMENT CHARACTERISTIC The figure at Annexure – IB shows a typical Force - Displacement curve.

The shape of the Force - Displacement curve or Hysteresis Cycle should be regular and symmetrical as shown here. The hysteresis cycle should be free from: − flex as shown in this figure with letter A & B − local vibrational phenomena − jumps and sudden change in the shape of

the curve

C. ENDURANCE TESTING After ascertaining the damping characteristics as mentioned above, the hydraulic damper samples to be tested shall be subjected to endurance testing as follows: .1 Procedure

Two of the samples that have passed the tests under Para 5 shall be randomly selected for endurance testing. The hydraulic dampers shall preferably be tested in their normal plane of operation.


Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. iii

The hydraulic damper shall be connected to the testing machine with its flexible end mountings in the same manner as it is done on the locomotives. No additional flexible elements shall be used for this purpose. However, in the case of hydraulic dampers where such installation is not possible, flexible elements suitable for installing the hydraulic damper on testing machine (having characteristics identical to that of flexible element provided on the hydraulic damper), shall be allowed to be used provided prior approval of RDSO has been obtained for this purpose. The endurance testing machine shall enable keeping one end of the hydraulic damper fixed and the other end oscillating at 1.67 Hz with amplitude of ±9.5mm from mean position corresponding to a maximum velocity of 10 cm/sec. Hydraulic damper shall thus be subjected to a total 3 million cycles. The damper oil temperature should not exceed 70°C temperature during the endurance test. After completion of 8 lakh, 16 lakh, 24 lakh and 30 lakh cycles each, the hydraulic damper shall be removed from endurance testing machine and re-tested for overall damping characteristics as mentioned above after it cools to room temperature so that the damping characteristics test is carried out with the hydraulic damper at a temperature between 27° C to 33° C inclusive. The necessary data should be recorded as per the Proforma enclosed at Annexure – I C. A continuous record of endurance testing shall be maintained in the log sheet as per the Proforma placed at Annexure – I D. The cyclic working on endurance testing machine shall preferably be continuous except for short intervals when hydraulic damper is removed for checking their capacity or when circumstances are beyond the control of testing agency e.g. power failures etc.

.2 Criteria for Acceptance After completion of recommended endurance cycles as above, the sample hydraulic dampers shall be considered to have passed this endurance test if: a. No damage or distortion to damper components or oil leakage occurs. b. The damping characteristics do not deteriorate beyond ±20% of rated damping

capacity upto 16 lakh cycles and ±25% beyond that.

6. INSPECTIONS AND TEST REPORT After completion of endurance test, the details of the test shall be compiled giving description of the test, all measured data prior to, during and after the test. If the test damper fails, the cause of failure should also be investigated and corrective actions to be taken by the manufacturer.


Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. iv

Annexure IA DAMPER PERFORMANCE TEST

Damper No.

Damper Details Condition (Before/After) Strength Test

Damping Force (Kg) Capacity

(Kg) at 10 cm/sec

Type (Vertical/ Lateral)

At Variable Frequency & Stroke At Constant Stroke of ± 9.5 mm At Constant Frequency of 1.67 Hz

At Piston Velocities of At Piston Velocities of 1.67 Hz

± 9.5 mm 0.83 Hz

± 19 mm 0.56 Hz

± 28.5 mm 20 (mm/sec)

60 (mm/sec)

100 (mm/sec)

20 (mm/sec)

60 (mm/sec)

100 (mm/sec)

Comp Expn Comp Expn Comp Expn Comp Expn Comp Expn Comp Expn Comp Expn Comp Expn Comp Expn 1. Before

After

2. Before

After

3. Before

After

4. Before

After

5. Before

After


Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. v

Annexure IB

A TYPICAL FORCE - DISPLACEMENT CHARACTERISTIC LOOP OF A HYDRAULIC DAMPER


Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. vi

Annexure IC DAMPER PERFORMANCE DURING / AFTER ENDURANCE TEST

Product: Vertical hydraulic damper / Lateral damper Capacity (Kg): Application: Primary / Secondary RDSO Drawing No: Sample No:

Test Dates: Start: Completion:

S.No. Endurance Test Stage

At Constant Stroke of ± 9.5 mm At Constant Frequency of 1.67 Hz

At Piston Velocities of At Piston Velocities of 20

(mm/sec) 60

(mm/sec) 100

(mm/sec) 20

(mm/sec) 60

(mm/sec) 100

(mm/sec) Comp Expn Comp Expn Comp Expn Comp Expn Comp Expn Comp Expn

1. Initial

2. After 8 Lakh Cycles





Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. vii

Annexure ID LOG SHEET FOR ENDURANCE TESTING DATA OF HYDRAULIC DAMPERS

Product: Vertical hydraulic damper / Lateral damper Capacity (Kg): Application: Primary / Secondary RDSO Drawing No: Sample No:

Test Dates: Start: Completion:

Stroke (mm): Frequency (Hz): Velocity (cm/sec):

Sl. No.

Date Started time

Stopped time

Total hours

No. of cycles

Cumulative no. of cycles

completed

Temperature of damper

(ºC)

Remarks


Motive Power Directorate (VDG), RDSO, Lucknow No. MP.0.49.00.16 (Rev.00) March 09 Page No. viii

Annexure II

QUALITY ASSURANCE & GUARANTEE CERTIFICATE (Reference – Clause 7 of Specification No. MP.0.49.00.16)

No. …………………………….. Dated:………………………….

Railway : ……………………………..

P.O. No. : …………………………….. Dated:………………………….

Quantity : …………………………….. Consignee:……………………

Hydraulic Damper Description: ……………………………………………………………......…………………….

……………………………………………………………………..……………….

i. THIS IS TO CERTIFY THAT THE HYDRAULIC DAMPERS INDICATED IN THIS PURCHASE ORDER HAVE BEEN SUBJECTED TO OUR INSPECTION AND TEST PROCEDURES AND ARE FOUND TO CONFORM TO THE ORDER/DRAWING/SPECIFICATION REQUIREMENTS.

ii. THE QUALITY CONTROL PROCEDURES IN RESPECT OF THIS SUPPLY ARE IN ACCORDANCE WITH OUR QUALITY MANUAL AND AS PER APPROVED QUALITY ASSURANCE PLAN.

iii. THIS IS TO CERTIFY THAT EACH HYDRAULIC DAMPER SUPPLIED AGAINST THIS PURCHASE ORDER SHALL FUNCTION SATISFACTORILY FOR THE INTENDED APPLICATION & PERIOD SPECIFIED IN THE RELEVANT SPECIFICATION.

Dated: Q.C. INCHARGE (SIGNATURE & SEAL OF THE MANUFACTURER)

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