Deutsche Bahn’s New Trains Run More Efficiently with Advanced Technologies from SKF

Bearing design and integration expertise from SKF has helped Siemens and Bombardier to create a new generation of reliable, highly efficient passenger trains for Deutsche Bahn – Germany’s national rail operator.

The ICE-4 passenger train will become the backbone of Deutsche Bahn’s (DB) long distance network. The new train has been designed using a modular concept, allowing it to be reconfigured to suit a wide range of different applications on the German rail network. SKF has been involved in the €6 billion project since 2012, working directly with Siemens, the manufacturer of the new train, and with Bombardier, which supplies the trailer bogies and coaches.

Meeting the demanding performance and reliability specifications for the ICE-4, presented a host of technical challenges. The new train will operate routinely at 250kph. Naturally, every component used on the train must meet stringent safety criteria, but DB also needs to keep tight control over its operating costs. That required the designers to maximize energy efficiency and minimize routine maintenance requirements.

tapereSKF Tapered Roller Bearing Unitd-roller-bearing-unit-skf

SKF Tapered Roller Bearing Unit

Smart Sensor Integration

The trailer bogies, supplied by Bombardier and named BOMBARDIER FLEXX Eco, use an inboard bearing arrangement enabling lower weight and energy consumption. For this application, SKF developed a special tapered roller bearing unit (TBU), with integrated sensors to monitor the speed and direction of rotation of each wheelset. Building the sensors into the bearing unit itself minimizes the space required for the whole assembly, an important characteristic in the inboard configuration, where space is limited. Used in the control of the train’s braking system, the signals generated by the sensors have been customized specially to suit the requirements of the customer. The safety critical nature of this application calls for levels of redundancy. For this reason, both of the bearing units on each axle are equipped with dual sensors. An additional sensor in each bearing monitors its operating temperature, providing an important early warning indicator in the event of temperature increase.

“The inboard bearing configuration is a relatively new configuration in high speed rail applications, requiring a new technology,” says Wolfgang Schatzer, Strategic Account Manager, Railway Industry at SKF. “The size of the axle, and the loads involved, require an unusually large bearing. The inner diameter is in the range of 180mm, compared to the 150mm size normally used in outboard bearing arrangements, but this is an area where SKF has a lot of experience and expertise.”

Extended Maintenance Intervals

Modern intercity trains must meet highly demanding criteria for reliability, together with long intervals between maintenance. The customer specifications required a calculated bearing life of 3,3 million km. “The total operating life of the bearings is important, but to reduce cost of ownership, the period between maintenance operations can be even more significant,” says Schatzer. “Extending the maintenance intervals for rail bearings has been a major area of research and development for SKF in recent years, and we had confidence from our own testing and the use of our bearings technologies in the field that we would be able to fulfil the customer’s requirements.”

Key to extending the maintenance intervals in a tapered bearing unit (TBU) is to minimize friction and thereby reduce operating temperatures, which allows the lubricant inside the bearings to work for a longer time before replacement.


Cylindrical Roller Bearing Unit

Supplying the bearings and sensors as a sealed and greased unit, has multiple benefits for the customer, both in development and production, with fewer, more clearly defined interfaces between the bearings, sensors and other parts of the train.

The motor bogies, developed by Siemens themselves, use a more conventional outboard bearing arrangement, an area where SKF also has extensive experience, including from some of the most demanding high-speed applications in the world. Again, the company opted for an integrated bearing unit solution, this time using cylindrical roller bearings. The motor bogies had even more stringent durability requirements, with customer specifying 1.65 million km before bearing service.

Well-Coordinated Test Program

To prove their reliability and performance, all the new bearing units had to undergo a two year, multi-step testing and validation process. Validation began in a virtual environment, using computer simulation of the design. Then SKF used its in-house test center in the Netherlands, the largest facility of its type in Europe, to test the bearings in realistic operating conditions. Prototype bearing units were mounted in real ICE-4 axleboxes and ran for the equivalent of 800,000 km, during which the bearing temperature and performance was closely monitored. This test took around four months and was designed to emulate a wide range of operating conditions. Further testing of bearings fitted to prototype trains was conducted by Siemens at its test and validation center, in Wegberg-Wildenrath, Germany, followed by field tests on the DB network.

High-Efficiency Motor and Gearbox Components

In the traction units, SKF has also been selected to provide energy efficient taper roller bearings for the main gearbox output shafts, with a 240mm bore diameter. “Energy efficiency is an increasingly critical consideration for rail operators as they seek to control the lifecycle costs of their trains, says Jochen Baum, Manager Drive Systems Competence Center, Railway Industry at SKF. “The SKF solution uses a low-friction bearing, and it is the first time a bearing of this design is used in a railway application.” The use of a low-friction bearing helps to improve the service life of the bearing, he explains. “Less friction leads to a lower operating temperature. During the customer’s test cycle, we could show that our low-friction bearing operated at a temperature almost 30 degrees lower than a conventional bearing. The lower operating temperatures gives what could be described as a “temperature margin” which makes the bearing more robust to withstand unfavorable conditions raising temperatures, such as fluctuating torque/speed, hot ambient temperatures, and not ideal oil supply.” SKF has also developed a specially modified deep groove ball bearing, designed to resist high axial shock loads, and supplies cylindrical roller bearings for use in the traction motors of the train.


The new ICE 4 © Siemens

Rolling Out Across the Network

Siemens delivered the first prototype trains to DB in 2014, operational tests on the public network began in 2016 and the ICE-4 will formally enter service in 2017. SKF will work closely with Siemens and DB to monitor the performance of the bearings during the first few hundred thousand kilometers of operation, and, if they perform as well in operation as they did during the test period, the maintenance intervals will be gradually extended over time.

“In these kind of applications, it very important to be involved from the early stages,” says Schatzer. “That allowed us to provide input not only into the design of the bearings, but also the surrounding elements, which often have a significant impact on the overall performance of the system.”

Initially, the ICE-4 will replace DB’s existing Intercity and Eurocity fleets, some of which have been in operation since the 1970s. Over time, the train will also replace the company’s ICE1 and ICE2 units, eventually accounting for around 70 percent of the company’s inter-urban services by revenue . DB has placed an initial order for 130 new trains, and it has entered a framework agreement with supplier Siemens mobility for eventual delivery of up to 300 trainsets.

Original article © SKF.


Get your news featured on Railway‑News

Please fill in the contact form opposite. A member of the team will be in touch shortly.

Follow Railway-News on LinkedIn
Follow Railway-News on Twitter
object(WP_Post)#9741 (24) { ["ID"]=> int(9314) ["post_author"]=> string(1) "3" ["post_date"]=> string(19) "2016-11-03 14:00:08" ["post_date_gmt"]=> string(19) "2016-11-03 14:00:08" ["post_content"]=> string(5643) "

Innovative and Reliable Bearing, Condition Monitoring and Lubrication Solutions for Rail Around the World

SKF's engineering knowledge combined with years of practical experience, rigorous testing, quality control and validation, is the solid base on which reliable solutions to the railway industry are developed and offered. SKF offers a wide variety of advanced product solutions for a broad range of railway rolling stock, including high-speed and very high-speed trains, diesel and electric locomotives, diesel and electric multiple units, freight cars and mass transit vehicles such as metro cars and tram cars.

Axleboxes and Wheelset Bearings

Designed for reliability and safety, SKF offers a wide choice of wheelset bearing solutions for all kinds of railway rolling stock. SKF focuses on reducing friction which lowers both energy consumption and operating temperature. This leads to longer grease life and hence extended maintenance intervals. For example, SKF Passenger bearing 1.7 M km maintenance free axle box bearing is world leading, without compromising safety. Axleboxes are the link between the rotating wheelset and the quasi-static frame of the bogie or running gear of a railway vehicle. Axleboxes and Wheelset bearings/units have always been a vital component in the reliability and safety of railway rolling stock. Through comprehensive fatigue testing capabilities, SKF ensures reliability while balancing weight and cost requirements. Millions of SKF axleboxes are in service throughout the world. SKF has extensive experience in finding robust solutions for freight wheelset applications, running in every climate, from moderate Mediterranean to tropical desert to sub-zero wilderness. Innovative sealing technology provides longer grease life and lower friction enabling extended maintenance intervals. SKF is certified according to all relevant industry norms. [gallery ids="9316,9354,9355"]

Drive System Bearings

With technical risk assessment capabilities and equipped with advanced modelling and calculation tools, SKF drive system competence center with experienced engineers are dedicated to finding the optimal solution for each customer’s unique application conditions. SKF bearings for drive systems are designed to cope with variations in speed, temperature, load, vibration, shocks and electrical system properties. Additionally, traction motor bearing units are designed to handle in-application contamination and humidity. [gallery ids="9322,9323,9324"]

Lubrication Systems for Rail

Wheel and track conditions have a significant impact on rail productivity, and maintenance needs in this area dramatically affects the life-cycle cost of both vehicle and track. Thousands of trains around the world operate more reliably and efficiently thanks to SKF and Lincoln automatic lubrication systems. By delivering precise amounts of lubricant directly to the wheel/rail interface, automatic lubrication systems provide significant benefits in terms of wear, energy and noise reduction. [gallery ids="9325,9326,9327"]

Condition Monitoring for Rail

Reaching the rail industry’s goals of increased maintenance intervals and maintenance-free targets of more than one and a half million kilometres requires transitioning from time-based maintenance schedules to condition-based maintenance. This ensures that vehicles are only taken out of service for maintenance when it’s actually necessary. SKF bogie condition monitoring solutions use condition detection systems and sophisticated data processing algorithms to detect incipient damage. This allows sufficient time for repairs before significant mechanical failures can develop, helping to increase reliability and safety, while contributing to reduced maintenance costs, life cycle costs and total cost of ownership. With over a century of expertise in rotating machinery, SKF’s technological knowledge is deep, and our proprietary early warning algorithms and our diagnostic expertise are key advantages of our condition monitoring solutions. From components to full systems, SKF is a proven technology supplier with full bogie monitoring solutions ready to go, as well as customized technology options. [gallery ids="9319,9320,9321"]

Services Improving Safety, Reliability and Profitability

SKF offers a range of service solutions to help railway manufacturers and operators improve safety, reliability and profitability. Expert services available from SKF for the railway industry include a global network of railway application design expertise, production, service and remanufacturing centres - all of them supported by a highly trained network of sales, application and service engineers. SKF has been supplying bearings to rail applications for over 100 years and knows the environment where the fleets are operating. With this experience SKF also know that unforeseen things can happen. With a truly global footprint, SKF’s experts are never far away to help out. SKF’s bearing investigation and analysis services help to clarify service issues and offer root cause failure analysis to achieve vehicle maintenance interval extensions and optimum bearing performance. [gallery ids="9328,9330,11765"]   Through SKF’s bearing refurbishment offering they will help to reduce life cycle cost, optimize assets and help customers make a positive contribution to the environment. The refurbishment services are performed in accordance with OEM specifications and specifications of railway operators based on operating conditions." ["post_title"]=> string(3) "SKF" ["post_excerpt"]=> string(0) "" ["post_status"]=> string(7) "publish" ["comment_status"]=> string(6) "closed" ["ping_status"]=> string(6) "closed" ["post_password"]=> string(0) "" ["post_name"]=> string(3) "skf" ["to_ping"]=> string(0) "" ["pinged"]=> string(0) "" ["post_modified"]=> string(19) "2019-12-03 16:56:47" ["post_modified_gmt"]=> string(19) "2019-12-03 16:56:47" ["post_content_filtered"]=> string(0) "" ["post_parent"]=> int(0) ["guid"]=> string(59) "" ["menu_order"]=> int(71) ["post_type"]=> string(9) "suppliers" ["post_mime_type"]=> string(0) "" ["comment_count"]=> string(1) "0" ["filter"]=> string(3) "raw" }