Suspension bearing solutions SKF solutions for the automotive industry

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1 Suspension bearing solutions SKF solutions for the automotive industry Steering and Suspension The Power of Knowledge Engineering

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3 Solutions for the suspension system This publication provides with an overview on the SKF suspension bearings plus the SKF global presence, laboratories and testing. It highlights the benefits of suspension products for the car suspension applications and provides the basic data required for proper unit selection under given operating conditions. It also features a detailed technical description of suspension solutions product range, including external and internal design. The application data list at the end are for customer use. Table of contents Solutions for the suspension system... 3 The SKF suspension products range... 4 Suspension applications... 6 MacPherson Strut Bearing Unit Safety and good active drive... 8 R&D activities Simulation tools Finite Element Analysis Internal SKF dedicated tools Testing laboratory Metallurgical and chemical laboratory Bearings analysis centre Global presence of SKF suspension offering.. 12 Suspension bearing range Application data list

4 The SKF suspension products range Suspension systems serve a dual purpose. As well as contributing to the car s handling and braking for good active safety and driving pleasure, this system also keeps vehicle occupants comfortable and reasonably well-isolated from road noise, bumps, and vibration. However, these goals are generally at odds, so suspension tuning involves finding the right compromise. It is important for the suspension to keep the road wheels in contact with the road surface as much as possible, because all the forces acting on the vehicle do so through the contact patches of the tyres. The suspension also protects the vehicle itself and any cargo or luggage, from damage and wear. The designs of front and rear suspensions differ, yet combined they comprise one of the fundamental elements that determine the character of a vehicle, in terms of its road holding under a variety of road conditions. Suspension also helps the overall driving and travelling comfort, which is especially important for longer journeys. SKF provides the car industry with a wide selection of solutions for suspension systems and is particularly active in top-mount and spring seat arrangements for MacPherson strut systems. Main car manufacturers around the world adopt the solutions developed by SKF in its Centers of Excellence and Application Centers spread throughout the five continents. SKF has been improving its huge application knowledge and is able to provide its customers with robust solutions for any suspension application. SKF s products have passed several reliability tests, such as severe corrosion tests, which demonstrate the highest product durability and reliability. SKF suspension bearing evolution Metallic bearing with seal Metallic or plastic spring seat Composite bearing Metallic spring seat with seals Metallic insert overmoulded and joints bi-injection Robust design Progression toward integrated functions for a design capable of delivering: Efficiency: better use of material. Compactness: weight of system reduced (no metal spring seat, plastic components, simpler top-mount). Optimized value: the right balance of cost and function. Flexibility: easily adapts to surrounding components. Performance: seal design included inside SKF bearing. 4

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6 Suspension applications Some typical suspension bearing solutions BDA-1149 BDA-1029 BDA-1085 AD BDA-1141 D BDA-1152 B BDA-1137 B 6

7 A vehicle suspension must: Carry the vehicle mass Ensure contact between the tyre and the road Isolate the chassis from the disturbances created by the interface between tyre and road Guide the wheel in its displacement Four major suspension designs are used: MacPherson strut Double wishbone (also known as Short Long Arm or SLA) Multi-link Trailing-arm or leading-arm MacPherson Strut Bearing Unit (MSBU) MacPherson Strut is, without any doubt, the most widely used front suspension. This solution offers a good compromise between cost and performance, which is why SKF chooses to focus its attention on this particular design. SKF suspension bearings allow: Coil spring or complete suspension to rotate during steering movements with low, constant friction torque, enabling rotation of 45 degrees about the centre/straight ahead position Spring rotation during normal suspension movements and transmission of suspension loads to chassis: Axial load: 3 to 10 kn Radial load: 5 to 15% of axial load Shock load: up to 5 times axial load Each bearing design has been developed for a specific application in terms of: Loads Geometry of housings Protection from environment Semi-double or double when the spring load goes in a different rubber element than damper load Bearing adapted to each depending on suspension type: Small thrust ball bearing Sheet metal type Composite type Integrated MSBU with spring seat, bearing, top-mount and bump stop interface Deep groove ball bearing in addition to standard system The different components of this bearing show the most relevant functions: The overall ball system held by the cages (A), the balls roll inside the metal tracks (B), with the main scope of: Checking the direction of travel of the vehicle even if conditions Absorbing the load carried by the wheels and transmitting the load into the vehicle chassis The seals (C) isolate the bearing from water, mud and any other external contamination. The seat upon which the shock absorber spring rests, is made up of a metallic insert (D) which is integrated into the bearing seat made of composite material. B A Two main types of top-mount arrangement are known depending on loads path: Single path when spring and damper loads are taken by the same rubber D C 7

8 Safety and good active drive The quality of a bearing is primarily determined by the ability of an engineering team to transform customer requests into a robust design. SKF s car steering and suspension product development phase is managed by the Center of Excellence in Saint- Cyr-sur-Loire in France. Our research and development team is able to provide support for the customer, with bearing selection and the development of new bearings according to their needs, and with global application improvements. Robust design is made possible by SKF s extensive experience with simulation tools, advanced testing facilities, and our capacity for physical analysis of the bearing from the macroscopic to the microscopic. The team s global experience with these applications is a major contributing factor to ongoing development of The Power of Knowledge Engineering. This multi-disciplinary team is also able to cover all aspects of a project, from material and design selection, through to the production phase and quality assurance, to develop completely new solutions that answer all application requirements. As well as our product, its environment is also high priority, in adapting bearings to their surrounding components with the best interfaces and internal designs. Moreover, we are there to share our knowledge with the customer, and provide support with global application design involvement. With our continuous design improvement and advanced engineering, we are also able to anticipate the potential needs of the customer, to stay innovative in offering new and helpful solutions. R&D activities With a strong historical background in the design of a wide range of bearings already in production, the research and development team is able to meet customer needs with customised adaptations of existing technologies. 8

9 Simulation tools Finite Element Analysis The team is focused on simulation tools such as Finite Element Analysis in order to check the behaviour of the bearing in its environment : Check that the bearing is suitable for requirements with different complex load cases Check the deformation of the bearing in its environment to ensure a good global functioning of the application Support the customer in selecting the best interfaces with external components Meet specific requests, such as simulating special phases of the life cycle of the bearing (assembly, disassembly) in order to answer customer questions Internal SKF dedicated tools In addition, SKF dedicated softwares such as BEAST and Bearing Simulator are used to select best sizing, design, contact areas and material for the bearing s internal geometry such as balls raceways and lubrification. Furthermore these simulation tools help SKF to determine and evaluate the lifetime of the bearing inside the suspension application. These tools are also used to provide robust design and material selection, especially with polymer and rubber components in all life cycles of the bearings: Ensure that the chosen design and material are safe for the given load cases Improve the bearing components in order to optimize the compromise between robustness and weight Compare different designs to select the best solutions 9

10 Testing laboratory The SKF Testing laboratory is able to manage validation phases of the bearing and its surrounding components with several typical tests. Here is a non-exhaustive list of what they can do. The testing laboratory is able to provide its expertise on bearing performance analysis as : Torque (at different temperatures) Radial displacement Pull apart Endurances at different oscillation, frequencies and temperatures They can validate the application with various tests to determine the suitability of the bearing in the complete suspension: Endurances on complete suspension Sealing endurance Shock test Furthermore, they can support the customer in gaining a better understanding of the complete suspension : Six axis torques and loads Spring load distribution analysis Comparative testing on suspension Spring pressure distribution (Mpa) The testing laboratory is focused on continuously developing new test rigs to support the customer, and to follow new design requirements. 10

11 Metallurgical and chemical laboratory The SKF metallurgical and chemical laboratory supports the development team by providing expertise on metallic, polymers and lubricant materials including their treatments, compatibilities and chemical behaviour (e.g. corrosion). They are involved in material selection, approval and audits, and are the owner of the SKF standards. The laboratory has all the necessary tools for understanding the behaviour of systems or parts, from global functioning to precise structural characteristics, such as: Dimensional measurements Material characterization: Penetrometer, Rockwel, Vickers Microscopical analysis of fractures, heat treatments or defect with Scanning Electron and FT-IR microscopes Material composition analysis with spectrometers, TGA, DSC, X-Ray diffractometer Temperature or corrosion testing machines Bearings analysis centre The teams working in our bearing analysis centre facilitate the expansion of SKF technical knowledge through customer support for bearing analysis, following vehicle testing in validation phases. They can help the customer to determine the root cause of failures in systems and if the bearing is involved they have the necessary knowledge to understand the mode of its failure. For that purpose we have a modern laboratory well-equipped with the necessary tools to analyse the bearing from disassembly to microscopical analysis. The laboratory team work in collaboration with other teams on further investigation, including testing and chemical analysis. All results are compiled and concluded on a wide range of topics. SKF testing enables us to exceed worldwide standards, rather than just to follow them. 11

12 Global presence of SKF suspension offering The manufacturing footprint comprises six different sites evenly spread across the business regions of Europe (France), North America (Mexico) Latin America (Brazil) and Asia (China, Korea and India). The technical support is coordinated through a Center of Excellence located in Europe (France) and deployed locally with application engineering centres close to our customers. The SKF Corporate R&D Center in Europe (The Netherlands), working across the different organizations, gives support for long term activities, while product validation and investigation are provided by technical centres located in Europe (France), United States (Detroit, MI), China (Shanghai), Japan (Chino) and India (Bangalore). Corporate R&D Center in Netherlands Application Center and Laboratory in USA Application and Technical Center, Production, Laboratory and Testing in China Center of Excellence and Production in France Application Centers in Germany Application Center, Laboratory and Testing in Japan Production in Mexico Production and Application Center in Korea Production and Application Center in Brazil Application Center and Production in India 6 production sites worldwide Technical centres in Europe, Asia and America Research and development centres in Europe 12

13 Suspension bearing range SKF suspension bearing range Dimensions Mass Static capacity Designation Internal diameter Outside diameter Inner ring width d D B mm kg N 12,2 45,3 19,3 0, BDA-1020 C 12,2 45,3 19,45 0, BDA-1149 C 14,2 45,3 13,45 0, BDA-1020 E 31,5 69,85 9,7 0, BDA , , BDA-1141 D , BDA-1032 BB , BDA-1059 AB , BDA-1127 B ,5 47,2 0, BDA-1085 AD ,8 0, BDA-1099 BD ,1 60,4 0, BDA ,5 97,35 16,8 0, BDA ,3 16,8 0, BDA-1130 AA 61,5 103,6 31,8 0, BDA-1132 D 61,6 88,2 12 0, BDA-1027 A 62, , BD1B D 65, ,75 0, BDA-1029 AE , BDA ,1 38 0, BDA-1148 A 1) 68,9 113,5 36,2 0, BDA-1106 AD 68, ,2 0, BDA ) 69, ,6 0, BDA ,5 0, BDA-1113 D ,7 0, BDA-1152 B 1) ,7 39 0, BDA-1137 B 1) ,7 39 0, BDA-1136 AD 79,5 111,5 14 0, BDAB CB ,7 0, BDA-1156 B 1) ,6 0, BDA-1159 A 1) ,4 29,57 0, BDA-1116 AC 1) Robust design bearing 13

14 BD1B D Robust, compact, light plastic bearing for heavy vehicles Excellent load-carrying capacity Optimized and cost-effective sealing performance due to special labyrinth seal 0 85,5 0,4 0 62,1 0,3 12 ±0,4 +0,4 62, ,4 BD1B D 62, ,

15 BDAB CB Robust, compact, light plastic bearing for heavy vehicles Excellent load-carrying capacity Optimized and cost-effective sealing performance due to special labyrinth seal 0 111,5 0,5 +0,5 79, ±0,3 106,5 BDAB CB 79,5 111,5 14 0,

16 BDA-1020 C or E Compact, light plastic bearing for small to medium-sized vehicles Metal raceways combined with plastic lower housing Excellent load-carrying capacity Optimized and cost-effective sealing performance due to special labyrinth seal 45,3 12,2 ±0,5 19,3 13,3 ±0,3 6 ±0,3 +0,3 20,3 0 +0,3 26,8 0 40,4 ±0,2 Dimensions refer to BDA 1020C BDA-1020 C 12,2 45,3 19,3 0, BDA-1020 E 14,2 45,3 13,45 0,

17 BDA-1149 C Compact, light plastic bearing for small to medium-sized vehicles Metal raceway combined with plastic lower housing Excellent load-carrying capacity Optimized and cost-effective sealing performance due to special labyrinth seal Optimized clearances 45,3 ±0,2 12,2 ±0,05 19,45 14,45 ±0,3 5 ±0,15 20,45 ±0,15 26,9 ±0,1 40,4 ±0,2 BDA-1149 C 12,2 45,3 19,45 0,

18 BDA-1027 A Robust, compact, light plastic bearing for heavy vehicles Excellent load-carrying capacity Optimized and cost-effective sealing performance due to special labyrinth seal 0 88,2 0,4 12 ±0,3 61,6 ±0,3 0 86,35 0,3 BDA-1027 A 61,6 88,2 12,0 0,

19 BDA-1029 AE Fully metal angular contact bearing for medium-sized vehicles Excellent sealing performance due to contacting seal integrated in the ball set cage 0, ,5 65,5 19,75 +0,4 9,13 0,2 10,62 ±0,2 66,8 ±0,3 71,35 ±0,15 BDA-1029 AE 65,5 100,0 19,75 0,

20 BDA-1032 BB Composite bearing with integrated spring seat and top-mount interface Metal spring seat resistant to bumpstop loads Optimized and cost-effective sealing performance due to a combination of external labyrinth and internal contacting seals ,9 ±0,2 15,6 ±0, ,4 ±0, ,5 ±0,3 83,7 ±0, BDA-1032 BB 35,0 107,0 36,0 0,

21 BDA-1050 Very compact and light angular contact bearing for light, medium and heavy vehicles Optimized and cost-effective sealing performance due to a combination of external labyrinth and internal contacting seals 69,85 ±0,15 31,5 9,7 ±0,3 35,3 64,5 BDA ,5 69,85 9,7 0,

22 BDA-1059 AB Composite bearing with integrated spring seat and top-mount interface Many functions incorporated (i.e. bump-stop loads, dust boot clipping, inclined spring seat, low weight, etc.) Optimized and cost-effective sealing performance due to special labyrinth seal ,9 ±0, ±0, ±0,3 57 ±0, BDA-1059 AB 35,0 112,0 44,0 0,

23 BDA-1074 Composite bearing with integrated spring seat and top-mount interface for medium-sized vehicles Metal spring seat to increase rigidity Optimized sealing performance due to a combination of two contacting seals 102,1 ±0,3 72,2 ±0, ±0,5 8,5 ±0,5 68 ±0,3 80 ±0,3 112 BDA ,0 112,0 25,0 0,

24 BDA-1085 AD Composite bearing with integrated spring seat and top-mounts interface Metal spring seat resistant to bumpstop loads Metallic spring seat overmolded to lower deformation and stress Optimized and cost-effective sealing performance due to a combination of external labyrinth and internal contacting seals 120,5 108,15 69,9 17,5 ±0,5 47,2 21,7 29,7 ±0, ,4 88,5 ±0,2 BDA-1085 AD 35,0 120,5 47,2 0,

25 BDA-1099 BD Composite bearing with integrated spring seat and top-mount interface Metal spring seat resistant to bumpstop loads Optimized and cost-effective sealing performance due to a combination of external labyrinth and internal contacting seals Spring support function incorporated in the lower housing to protect against spring breakage ,9 ±0,2 18,4 ±0,5 36, ,4 ±0, ,5 79,7 ±0,3 16,7 BDA-1099 BD 35,0 129,0 36,8 0,

26 BDA-1106 AD Composite bearing with integrated spring seat and top-mount interface for heavy vehicles Optimized and cost-effective sealing performance due to a labyrinth seal Latest SKF Six Sigma design of ball set, optimized for radial capacity, displacements and over-turning moments 112,8 68,9 ±0,2 14,2 ±0,5 36,2 22 ±0, ,5 ±0,3 113,5 BDA-1106 AD 68,9 113,5 36,2 0,

27 BDA-1113 D Composite bearing with integrated spring seat and top-mount interface for heavy vehicles Metal spring seat to increase rigidity Optimized sealing performance due to two contacting seals Latest SKF Six Sigma design of ball set optimized for radial capacity, displacements and over-turning moments ,25 ±0,15 19,8 ±0,5 41,5 19,9 ±0, ,3 83,6 ±0,3 128 BDA-1113 D 70,0 128,0 41,5 0,

28 BDA-1116 AC Composite bearing with integrated spring seat and top-mount interface for heavy vehicles Over-moulded metal spring seat to increase rigidity Optimized sealing performance due to two contacting seals Latest SKF Six Sigma design of ball set optimized for radial capacity, displacements and over-turning moments 140,4 ±0,6 99,1 ±0,5 29,57 17,57 ±0,56 12 ±0,3 98 ±0,5 107,9 ±0,3 139,5 ±0,5 BDA-1116 AC 98,0 140,4 29,57 0,

29 BDA-1127 B Composite bearing with integrated spring seat and top-mount interface Many functions incorporated (i.e. bump-stop loads, dust boot clipping, inclined spring seat, low weight, etc.) Optimized and cost-effective sealing performance due to special labyrinth seal 113 ±0,5 68,9 ±0, ±0, ±0,3 57 ±0, ,06 ±0,3 BDA-1127 B 35,0 113,0 44,0 0,

30 BDA-1129 Composite bearing with integrated spring seat and top-mount interface Inclined ball set to reduce bearing radial loads Many functions incorporated (i.e. bump-stop loads, dust boot clipping, inclined spring seat, low weight, etc.) Optimized and cost-effective sealing performance due to special labyrinth seal 115,3 67,7 ±0,2 25,2 7 60,4 ±0, ±0,3 76 ±0,3 82 ±0,3 122,1 BDA ,0 122,1 60,4 0,

31 BDA-1130 AA Robust, compact, light plastic bearing for medium-sized vehicles Optimized and cost-effective sealing performance due to a double labyrinth seal design Excellent load-carrying stability due to the axial ball set 97,35 ±0,25 16,8 ±0,5 4 ±0, ,6 ±0,2 95,8 BDA-1130 AA 58,0 97,35 16,8 0,

32 BDA-1132 D Composite bearing with integrated spring seat and top-mount interface Optimized sealing performance due to the external contacting seal Latest SKF Six Sigma design of ball set, optimized for radial capacity, displacements and over-turning moments 103,6 ±03 60,5 16,56 ±0,56 31,8 14 ±03 61,5 65,2 ±0,2 94,9 BDA-1132 D 60,5 103,6 31,8 0,

33 BDA-1133 Composite bearing with integrated spring seat and top-mount interface for medium-sized vehicles Metal spring seat to increase rigidity Optimized sealing performance due to a combination of two contacting seals ,3 ±0,15 33,6 18,2 ±0,5 15,4 ±0, ,7 ±0,2 85,9 ±0,5 115 ±0,3 BDA ,3 115,0 33,6 0,

34 BDA-1136 AD Composite bearing with integrated spring seat and top-mount interface for heavy vehicles Over-moulded external metallic spring seat to increase rigidity and to increase spring durability Optimized sealing performance due to two contacting seals Latest SKF Six Sigma design of ball set optimized for radial capacity, displacement and over-turning moments Inclined ball set to reduce bearing radial loads 108,1 ±0,3 78 ±0,3 6 8, ±0,25 86 ±0,3 126,7 BDA 1136 AD ,7 39 0,

35 BDA-1137 B Robust design bearing Composite bearing with integrated spring seat and top-mount interface for heavy vehicles External metallic spring seat to increase rigidity and to increase spring durability TPE robust seals have been designed to combine low friction torque with full protection against external pollution Latest SKF Six Sigma design of ball set optimized for radial capacity, displacement and over-turning moments Inclined ball set to reduce bearing radial loads 108,1 ±0,3 78 ±0,3 6 8, ±0,25 86 ±0,3 126,7 BDA 1137 B ,7 39 0,

36 BDA-1141 D Composite bearing with integrated spring seat, top-mount and bumpstop loads interface Optimized sealing performance due to two contacting seals Latest SKF Six Sigma design of ball set optimized for radial capacity, displacement and over-turning moments 109 ±0,5 69 ±0,2 18,6 ±0, ,4 ±0,25 34,75 ±0,25 61 ±0,3 82 ±0,30 BDA-1141 D 34, ,

37 BDA-1144 Robust, compact, light plastic bearing for medium-sized vehicles Optimized sealing performance due to the external contacting seal Excellent load-carrying stability due to the axial ball set 97,35 ±0,25 16,8 ±0,5 4 57,5 ±0,2 91,6 ±0,2 95,8 BDA ,5 97,35 16,8 0,

38 BDA-1148 A Robust design bearing Composite bearing with integrated spring seat and top-mount interface TPE robust seals have been designed to combine low friction torque with full protection against external pollution Latest SKF Six Sigma design of ball set optimized for radial capacity, displacement and over-turning moments 119,1 ±0,3 73,55 ±0,2 17 ±0, ,9 ±0,25 68 ±0,3 75 ±0,3 80 ±0,15 BDA-1148 A ,1 38 0,

39 BDA-1151 Robust design bearing Composite bearing with integrated spring seat and top-mount interface TPE robust seals have been designed to combine low friction torque with full protection against external pollution Latest SKF Six Sigma design of ball set optimized for radial capacity, displacement and over-turning moments 116 ±0,5 110 ±0,4 68,9 ±0,15 5,7 ±0,2 16,2 38,2 69,8 ±0,3 77,5 ±0,3 113,5 ±0,5 BDA , ,2 0,

40 BDA-1152 B Robust design bearing Composite bearing with integrated spring seat and top-mount interface Over-moulded metallic spring seat to lower deformation and stress TPE robust seals have been designed to combine low friction torque with full protection against external pollution Latest SKF Six Sigma design of ball set optimized for radial capacity, displacement and over-turning moments 112 ±0,2 74 ±0,3 15,8 ±0,6 7,9 ±0,2 31,7 78 ±0,4 86 ±0,3 123 ±0,5 BDA-1152 B ,7 0,

41 BDA-1156 B Robust design bearing Composite bearing with integrated spring seat and top-mount interface Over-moulded metallic spring seat to lower deformation and stress TPE robust seals have been designed to combine low friction torque with full protection against external pollution Latest SKF Six Sigma design of ball set optimized for radial capacity, displacement and over-turning moments 120 ±0,2 80 ±0,2 15,8 ±0,5 7,9 ±0,2 31,7 84 ±0,2 92 ±0,2 131 ±0,5 BDA-1156 B ,7 0,

42 BDA-1159 A Robust design bearing Composite bearing with integrated spring seat and top-mount interface Metallic insert over-moulded to upper housing for less deformation and stress with top-mount TPE robust seals have been designed to combine low friction torque with full protection against external pollution ,9 ±0,5 91 ±0,3 21,6 34,6 91,4 ±0,3 98 ±0,3 BDA-1159 A ,6 0,

43 Notes 43

44 Application data list Project information Platform, vehicle model, etc. Estimated volumes: Target dates and target price: Prototype date: SOP date: Application information Sketch of available space envelope including interfacing dimensions of surrounding components (e.g. top-mount, isolator, dust boot, 3D models and 2D drawing). Spring dimension: Bore diameter and wire diameter Bump-stop loads transmitted through bearing in Z axis? If so, what is the bump stop force (N)? Sealing requirements (severe environment?) Test specification Option for bumper integration Average pressure distribution in worst case load (please provide a sketch if available) Data to be filled in Area Pressure in MPa Bumper pressure distribution corresponding to shock load at N 44

45 Loads data Radial loads Radial loads Axial loads Distance between bearing axis and pierce point Distance from spring seat plane to bearing plane F x axis F y axis F z axis d x d y d z N N N mm mm mm Rebound position Design position Jounce position Spring load distribution on to bearing lower housing Spring load at rebound condition Spring load at design condition Spring load at jounce condition F x F y F z F x F y F z F x F y F z angle ( ) N N N N N N N N N

46 Vehicle outside z axis Vehicle inside d z C x/y axis F x /F x pp Spring load F z d x /d y Pierce point in bearing (x,y) plane C = Centre of the bearing PP = Pierce point d z = Distance between bearing plane and pierce point in z axis d x /d y = Distance between bearing axis and pierce point F x = Radial load on spring seat in x axis F y = Radial load on spring seat in y axis F z = Axial load on spring seat in z axis 46

47 Notes 47

48 Seals Mechatronics Bearings and units Services Lubrication systems er of Knowledge Engineering Combining products, people, and applicationspecific knowledge, SKF delivers innovative solutions to equipment manufacturers and production facilities in every major industry worldwide. Having expert ise in multiple competence areas supports SKF Life Cycle Management, a proven approach to improv ing equipment reliability, optimizing operational and energy efficiency and reducing total cost of ownership. These competence areas include bearings and units, seals, lubrication systems, mecha tronics, and a wide range of services, from 3-D computer modelling to cloud-based condition monitoring and asset management services. SKF s global footprint provides SKF customers with uniform quality standards and worldwide product availability. Our local presence provides direct access to the experience, knowledge and ingenuity of SKF people. skf.com SKF is registered trademark of the SKF Group. SKF Group 2014 The contents of this publication are the copyright of the publisher and may not be reproduced (even extracts) unless prior written permission is granted. Every care has been taken to ensure the accuracy of the information contained in this publication but no liability can be accepted for any loss or damage whether direct, indirect or consequential arising out of the use of the information contained herein. PUB 10/P /1 EN December 2014 Certain image(s) used under license from Shutterstock.com