The track-friendly high-speed bogie developed within Gröna Tåget A. Orvnäs 1 (former 2), E. Andersson 2, S. Stichel 2, R. Persson 3 1 Mechanical Systems, Interfleet Technology 2 Division of Rail Vehicles, KTH Royal Institute of Technology 3 Mainline and Metros, Bombardier Transportation 17 th Nordic Seminar on Railway Technology Tammsvik Herrgård, 3-4 October 2012
Outline (RSS) Active secondary suspension (ALS and AVS) 2
Gröna Tåget Research and development programme initiated in 2005 by Banverket (today: Trafikverket) closed by the end of 2012 Develop a concept for the next generation of high-speed trains for Nordic conditions Increase vehicle speed from today s 200 km/h up to 250 320 km/h Focus: vehicle dynamics, energy consumption, passenger issues, infrastructure, market needs, capacity, economics 3
Track-friendly high-speed bogie Challenge: contradiction between stability on straight track at high speed and reasonable wheel/rail wear in small- and medium-radius curves Developing and optimizing a track-friendly high-speed bogie by simulations, verifying the design by on-track tests and service use 4
Track friendliness Low wheel/rail forces on the track to avoid track wear and fatigue Minimize track deterioration, causing maintenance and renewal (high costs, traffic interruptions) Costs for track deterioration to be included in the track access charges Increased need for track-friendly vehicles High rail Low rail 5
Radial steering running gear Stiff connection prevents the wheelset to take up radial position Increased friction energy and wear in curves The longitudinal stiffness of the wheelset guidance is an important issue to allow radial self-steering 6
Running stability A certain amount of wheelset guiding stiffness is necessary to avoid bogie hunting Lower guiding stiffness can often be compensated by a higher amount of yaw damping A thorough optimization of other important parameters is also necessary 7
Strategy Running stability is just one of several targets Track friendliness and good ride quality are other important issues Therefore: design for sufficient running stability while optimizing the total performance 8
Concept Radial selfsteering (RSS) Active radial steering (ARS) Active lateral secondary suspension (ALS) Active vertical secondary suspension (AVS) What? Theoretical study 2005 06 2006 07 2006 07 2010 11 On-track tests 2006 07 2007 08 2007 08 2013? Service experience 2009 2009 First firm order 2010 9
(RSS) 10
Simulation conditions SIMPACK model of a Swedish REGINA car Ten wheel/rail combinations equivalent conicity: 0.01-0.4 (Type 1 and 2) Type 1 Type 2 l eq l eq Type 1 Type 2 3mm Dy 3mm Dy 11
Simulation results Wheel/rail wear 12
ΣY rms [N] Simulation results Running stability Extra soft Original yaw damping Soft Increased yaw damping Straight track Eq. conicity = 0.3 v = 275 km/h 13
On-track tests Different Swedish tracks (straight track, curves) Stability tests on straight track, equivalent conicity 0.1 0.8 Measurement results: Stability (ΣY 100rms ) = 30 % of limit value High cant deficiency curving at curve radius 300 m Measurement results: Wear (Y qst ) = 60 75 % of limit value Swedish high-speed record in September 2008: 303 km/h 14
Model validation Lateral track shift forces 15
Active secondary suspension (ALS and AVS) 16
ISO lateral (m/s 2 ) Play (mm) Active lateral suspension Measurement results 0.25 0.2 Ride comfort improvements Passive Active (ALS) ISO lateral DMA leading, outer ends ISO, active leading Reduced secondary lateral play Lateral play of secondary suspension above trailing bogie 0.15 0.1 0.05 60 40 20 0-20 -40-60 0 5 10 15 20 25 30 35 40 0 0 smallradius mediumradius largeradius straight Time (s) resulting in: possible speed increase for the same level of ride comfort maintained ride comfort although track conditions are unfavourable increased carbody width 17
ISO vertical (m/s 2 ) Active vertical suspension Simulation results Generally improved vertical ride comfort Less sensitivity for suspension stiffness Less sensitivity for carbody bending frequency 0.25 0.20 Modified vertical air spring stiffness Passive Active 0.15 0.10 0.05 0 0.5 1 1.5 2 2.5 Vertical stiffness (k /k) new 18
ISO vertical (m/s 2 ) ISO vertical (m/s 2 ) Active vertical suspension Simulation results Generally improved vertical ride comfort Less sensitivity for suspension stiffness Less sensitivity for carbody bending frequency Modified carbody bending frequency 0.25 0.20 Passively suspended carbody Bend freq 8 Hz Bend freq 9 Hz Bend freq 10 Hz Bend freq 11 Hz 0.25 0.20 Actively suspended carbody Bend freq 8 Hz Bend freq 9 Hz Bend freq 10 Hz Bend freq 11 Hz 0.15 0.15 0.10 0.10 0.05 0 front mid rear 0.05 0 front mid rear 19
Developing a bogie with relatively soft wheelset guidance to allow passive radial self-steering Appropriate yaw damping applied to ensure stability on straight track at higher speeds The design verified by simulations and on-track tests (ALS and AVS) mainly to improve ride comfort More than 600.000 km in service operation without reports of poor running behaviour or wheel reprofiling due to wear 20
Thank you for your attention! Contact: anneli.orvnas@interfleet.se