Steering bearing solutions - SKF.com · Steering bearing solutions SKF solutions for the automotive...

Steering bearing solutionsSKF solutions for the automotive industry

The Power of Knowledge EngineeringSteering and

Suspension

This publication provides with an overview on the SKF steering bearings plus the SKF global presence, laboratories

and testing. It highlights the benefits of steering products for the car steering applications and provides the basic

data required for proper unit selection under given operating conditions.

It also features a detailed technical description of steering 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 human-to-vehicle interface . . . . . . . . . . . . 3

The SKF steering products range . . . . . . . . . . . . . . 4

Steering applications . . . 6

•Steering column

•Electric power assistance

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 steering offering . . . . . 12

Steering column bearing range . . . . . . . 13

EPS bearing range . . . 32

Active steering bearing range . . . . . . . . . . . . . 40

Steering column bearing application data list . . . 42

Rack EPAS application data list . . . . . . . . . . . . 44

Solutions for the human-to-vehicle interface

3

The steering function within the

automotive field is the unique and

fundamental interface between driver

and vehicle, to which both active and

passive safety systems are connected.

Most of the technological challenges

concerning the future of the automotive

industry will see the steering sector

playing a major role. SKF is a market

leader in the supply of steering column

bearings, and one of the main suppliers

of bearings for electric steering systems,

which nowadays and even more so in

the future, will be used by the majority

of car manufacturers worldwide.

Steering electrification represents a first

step in the technological innovation of

automotive primary control systems. So

far, electric steering is conceived to

provide traditional steering functions,

such as the ones offered by hydrau-

lic-assisted systems, which means that

the potential for this application has not

yet been fully exploited.

Over the next few years however, we will

see an extraordinary evolution in terms

of active safety technologies in vehicles.

The steering system will play a key part

in facilitating connection between

wheel, brake and suspension areas,

thus improving overall vehicle

performance.

Sensorized components will become

fundamental in deploying effective

communication between each different

system, helping to achieve the complete

replacement of any mechanical element

of the car steering system with ‘steer-

by-wire’ technology.

This brochure illustrates state-of-the-

art car steering capability through the

SKF range of products designed to meet

main steering requirements.

EPS: Technology enabler - one step on the way to enhanced and future steering functionalities

The SKF steering products range

Future steering functions

Functional complexity

Enhanced steering functionsDriver assistance functionsDriver steering recommendation

Autonomous drivingActive collision avoidanceActive stability control

Basic steering functionsSteering comfort functionsSteering dynamic functions

Emergency steering assistanceElectronic vehicle stabilizationLane holdingTorque steer compensationParking assistance

Inertia compensationActive dampingBooster functionParameter steering

1990

Hydraulic

power steering

2000

Electrical

and hydraulic

power steering

2010

Electrical

power steering

2020

Steering

by wire

4

Some typical SKF steering bearing solutions

Steering applications

Steering column

Active steering

Rack and pinionElectric power assisted

ASCB P-WSCB DGBB 4PCBB

6

Steering column The steering column, pinion and rack

are mechanical parts of the vehicle

steering system, connecting the

steering wheel at its upper end to the

steering gear (rack and pinion) at its

lower end. The steering column

generally consists of a column tube fixed

to the car body, a steering shaft and a

transmission shaft. The steering shaft is

usually supported by two bearings at

the top and bottom of the column.

These upper and lower bearings are

developed by SKF specifically for this

application.

Product line steering column bearings

comprise several design types:

•Angular steering column bearing (ASCB)

•Pre-loaded wire steering column bearing (P-WSCB)

•Deep groove ball bearing (DGBB)

Electric power assistanceSKF has also been a key player in the

recent history of active steering (a type

of electric power variable gear ratio

power steering technology that varies

the degree to which the wheels turn in

response to the steering wheel). At

lower speeds, this technology reduces

the amount that the steering wheel

must be turned, improving performance

in situations such as parking and other

urban area traffic manoeuvres. At

higher speeds, the steering system

performance is such that normal

increased steering responsiveness at

speed is avoided, and so directional

stability is improved.

In a parking situation, the computer

varies the ratio so that the steering

wheel needs less than two turns to

move the wheels from lock to lock. As

vehicle speed increases, the steering

ratio also increases, so it takes larger

movements of the steering wheel to

move the wheels.

This lessens the usual increased

steering response to increased speed.

Besides providing variable steering

ratios, the computer is linked to the

vehicle stability control system to assist

with directional stability of the vehicle.

If the driver experiences a skid or slide

because of poor road conditions, the

active steering will react to information

from the yaw rate sensors, modifying

the steering angle of the front wheels to

stabilize the vehicle. This occurs much

faster than the driver can react. If the

active steering angle is insufficient, then

the stability control system intervenes

to give additional aid.

Safety is one of the prime objectives of

this system. Steering angle sensors on

the steering column sense the direction

the driver intends to take, and the

system only intervenes if the car is

beyond stable limits.

If an error or problem occurs in the

electronics, the computer shuts down

the operation of the electric motor,

locking the ring gear of the planetary

gear set and thus converting it to fixed

ratio steering. Finally, if there is a

problem inside the planetary gear unit,

a second shaft that runs from the

steering wheel shaft to the steering rack

allows for conventional steering instead.

The next generation steering functions

will be even more complex and will

include the so-called steer-by-wire

technology; an area where SKF has

already made significant progress. It is

providing an interesting challenge for

the engineering department, who are

working to extend the technology and

know-how boundaries related to

steering applications.

For a straightforward and clear explana-

tion of main steering functions, refer to

the graph on page 3.

Most power steering systems in cars

and light trucks were based on a

hydraulic technology during the last

decades (Hydraulic Power Steering =

the force to turn the wheels is provided

by a hydraulic piston, which is powered

by high pressure hydraulic fluid). Today

in most of the passenger cars and also

in first light trucks, the steering force is

provided by an electric motor. This is

one example of the many steps which

represents the evolution of steering

applications and functionalities

Electric power-assisted steering (EPS or

EPAS) uses an electric motor to reduce

steering effort, assisting the driver by

making it easy to steer the wheels.

This technology has also been devel-

oped to reduce fuel consumption and

C02 emissions as compared to hydraulic

power-assisted technology.

There are three main types of active

steering system, depending on equip-

ment installation and power to transmit:

•Column EPAS (light to medium vehicle)

•Dual-Pinion EPAS (medium segment vehicle)

•Rack EPAS (medium to high segment vehicle)

•Active front steering systems that allow the steering wheel angle and front wheel angle to adapt to vehicle speed

SKF has developed a range of products

for all EPS types and active steering

systems:

•Four point contact ball bearing

•Low noise deep groove ball bearing

•Flexible bearing

7

Safety and good active drive The quality of a bearing is primarily

determined by the ability of an engi-

neering team to transform customer

requests into a robust design.

SKF’s car steering and suspension

product development phase is managed

by the Global Center of Excellence in

Saint-Cyr-sur-Loire in France as well as

new steering center of excellence in

Germany. Our research and develop-

ment team is able to provide support for

the customers, 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’.

R&D activitiesWith 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.

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 improve-

ment and advanced engineering, we are

also able to anticipate the potential

needs of the customer, to stay innova-

tive in offering new and helpful

solutions.

8

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

These tools are also used to provide

robust design and material selection,

especially for 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

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

steering application.

9

Testing laboratoryThe SKF Testing laboratory can manage

bearing validation phases to homolo-

gate steering bearings in application

conditions.

The testing laboratory delivers its

expertise on bearing performance

analysis as:

•Torque to rotate (at different temper-atures and under misalignment)

•Stiffness behaviour/deflection

•Noise and vibration

•Temperature cycle test/Ageing

SKF is able to test the bearing durability

on dedicated endurance testbenches,

representing the application conditions.

SKF offers to run specific tests for

steering column bearing products, such

as:

•Assembly and disassembly loads

•Alternating axial&radial loads for static load testings

•Simulation of crash loads on bearing level

Furthermore SKF can support custom-

ers on specific test demands, helping

with its experience to establish new

tests and testing procedures.

The testing department is therefore

focused on continuos development for

new test rigs in order to support

customers with growing market

requirements on their systems and

subcomponents.

10

Metallurgical and chemical laboratoryThe SKF metallurgical and chemical

laboratory supports the development

team by providing expertise on metallic,

polymers and lubricant materials

including their treatments, compatibili-

ties 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 function-

ing to precise structural characteristics,

such as:

•Dimensional measurements

•Material characterization: Penetrom-eter, 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 centreThe 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 deter-

mine 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 collabora-

tion 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

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).

Global presence of SKF steering offering

The manufacturing footprint comprises

five different sites evenly spread across

the business regions of Europe (France,

Germany, Italy), North America (USA)

and Asia (India). The technical support is

coordinated through the Center of

Excellence for Steering products located

in Europe (Germany) and deployed

locally with application engineering

centres close to our customers.

Production in France, Germany and Italy

Steering Center of Excellence in Germany

Corporate R&D Center in Netherlands

Application Center, Laboratory & Testing

in JapanProduction in USA

Application Center in Brazil

Application and Technical Center, Laboratory and

Testing in China

Application Center in Korea

Application Center and Production in India

Application Center and Laboratory in USA

● 5 production sites worldwide

● Technical centres in Europe, Asia and America

● Research and development centres in Europe

Global Center of Excellence CSS in France

12

Steering column bearing range

Angular steering column bearing (ASCB)

Dimensions Mass Designation

Internal diameter Outside diameter Inner ring widthd D B

mm mm mm kg –

N 23 x 23 43 15,7 0,030 BA1-3982 AN 23 x 23 43 15,7 0,027 BA1-3983 B30 43 15,7 0,029 BA1-3973 CC30 43 15,7 0,026 BA1-3978 B30 43 15,7 0,029 BA1-399030 43 15,7 0,026 BA1-399130 43 15,5 0,025 BA1-399230 43 15,7 0,029 BA1-3993

Pre-loaded wire steering column bearing (PWSCB)



mm mm mm kg –

22 40 9,15 0,028 BAQ-0012 AA1)

22 40 10,5 0,034 BAQ-0028 E1)

22 40 10 0,048 BAQ-0084 A22 36 10,3 0,033 BAQ-0065 A25 44,1 10 0,061 BAQ-009625,9 44,1 9 0,053 BAQ-0088 A28 44 10,8 0,051 BAQ-0057 DA30 44 10 0,043 BAQ-0091 A30 44 10,45 0,043 BAQ-0064 C

Deep groove ball bearings (DGBB)



mm mm mm kg –

25 37 7 0,021 DGBB type 6180530 42 7 0,027 DGBB type 61806

1) Examples to show additional function integration that could be applied on all PWSCB product line

13

SKF steering column bearing range: Overall dimensions

Designation Bore diameter External diameter Width Weight

– mm mm mm kg

BA1-3973 CC 30 43 15,7 0,029

43,05 ±0,05

15,7

45,4 ±0,2

2,1

+0,1030,12 –0,05

Benefits•Low torque and high stiffness

•Wavy spring integrated

•Conductive bearing

•No machining required on shaft and housing

BA1-3973 CC

14

Benefits•Low torque andhigh stiffness


BA1-3978 B



– mm mm mm kg

BA1-3978 B 30 43 15,7 0,026

15,7

2

45,4 ±0,2+0,10

30,12 –0,05

43,05 ±0,05

15




•Square inner sleeve


BA1-3982 A



– mm mm mm kg

BA1-3982 A N 23 x 23 43 15,7 0,030

15,7

2,1

43,05 ±0,05

45,4 ±0,2

+0,2 23,15 0

16


•Square inner sleeve


BA1-3983 B



– mm mm mm kg

BA1-3983 B N 23 x 23 43 15,7 0,027

15,7

+0,2023,15 0 45,4 ±0,2

43,05 ±0,05

2

17



– mm mm mm kg

BA1-3990 30 43 15,7 0,029

15,7

2,1

43,05 ±0,05

45,4 ±0,2+0,10

30,12 –0,05

Benefits•Low noise solution

•Low torque and high stiffness




BA1-3990

18



– mm mm mm kg

BA1-3991 30 43 15,7 0,026

15,7

2

43,05 ±0,05

45,4 ±0,2+0,10

30,12 –0,05




BA1-3991

19



•Non flange bearing


BA1-3992



– mm mm mm kg

BA1-3992 30 43 15,5 0,025

15,5

3

+0,1030,12 –0,05

43,05 ±0,05

20



– mm mm mm kg

BA1-3993 30 43 15,7 0,029






BA1-3993

15,7

2,1

43,05 ±0,05

44,65 ±0,15+0,10

30,12 –0,05

21



– mm mm mm kg

BAQ-0012 AA 22 40 9,15 0,028

Benefits•Angular deviation and misalignment

permissible

•Low torque

•High axial retention


•Dumping function

•High misalignment tolerance

BAQ-0012 AA

9,15 ±0,15

7,55 ±0,1

(36)

40 ±0,15

–0,0922 –0,19

22



– mm mm mm kg

BAQ-0028 E 22 40 10,5 0,034

Benefits•Angular deviation and misalignment

permissible

•Low torque

•Interference possible with housing to ensure minimum extraction load

•High axial retention


•Dumping function

•High misalignment tolerance

BAQ-0028 E

10,5 ±0,2

7,55 ±0,1

–0,0922 –0,19

(36)

+0,1 40 0

23



– mm mm mm kg

BAQ-0057 DA 28 44 10,8 0,051

0,9 0,9 9 ±0,2

+0,0244,15 –0,03

+0,00527,87 –0,009

Benefits•Vibration absorption

•Low torque

•High radial and axial stiffness (pre-loaded bearing)

•Axial separation load 10 kN



BAQ-0057 DA

24



– mm mm mm kg

BAQ-0064 C 30 44 10,4 0,043

9,05 ±0,15

+0,0244,1 –0,03

–0,0529,87 –0,05

10,4


•Low torque

•No axial and radial clearance (pre-loaded bearing)

•Best compromise between stiffness and friction torque




BAQ-0064 C

25



– mm mm mm kg

BAQ-0065 A 22 36 10,3 0,033

0,6 0,69,05 ±0,15

36,15 ±0,03

+0,00521,87 –0,009


•Low torque

•High radial and axial stiffness (pre-loaded bearing)




BAQ-0065 A

26



– mm mm mm kg

BAQ-0084 A 22 40 10 0,048

10 ±0,2

40,06 +0,03

10 ±0,1 inner ring

+0,00521,87 –0,009


•Low torque



•Axial separation load 15 kN (min)



BAQ-0084 A

27



– mm mm mm kg

BAQ-0088 A 26 44 9 0,053


•Low torque






BAQ-0088 A

9,05 +0,15

+0,0244,1 –0,03

+0,00825,89 –0,006

28



– mm mm mm kg

BAQ-0091 A 30 44 10 0,043

9,05 ±0,15

10,5 ±0,1

+0,0244,1 –0,03

+0,0529,87 –0,09


•Higher and controlled torque (following specific requirements)






BAQ-0091 A

29



– mm mm mm kg

BAQ-0096 25 44 10,4 0,061

9,05 ±0,15

+0,0244,1 –0,03

+0,00825 –0,006

10,4 ±0,1


•Higher and controlled torque (following specific requirements)






BAQ-0096

30



– mm mm mm kg

DGBB type 61805 25 37 7 0,021

DGBB type 61806 30 42 7 0,027

25 37

7

Benefits•High radial and axial stiffness


DGBB type 61805 DGBB type 61806

31

EPS bearing range

SKF Column / dual pinion EPAS bearing range

Deep groove ball bearings

d D B Mass Static capacity Dynamic capacity DesignationCo C

mm mm mm kg N N –

6 19 6 0,009 950 2 210 626-2ZT N9/NH LHT237 22 7 0,013 1 370 3 450 627-2ZT N9/C2H LHT237 22 7 0,013 1 370 3 450 BB1-0361 A20 42 12 0,069 5 000 9 360 BB1-0214 BC22 42 9 0,049 4 300 7 200 BB1-360022 42 12 0,062 5 000 9 360 BB1-0451 B25 42 9 0,043 4 300 7 200 BB1-357825 47 12 0,079 6 550 11 200 BB1-023525 47 12 0,079 6 550 11 200 BB1-0266 C

d = Bore diameterD = Outside diameterB = Inner ring width

SKF rack EPAS bearing range

4 point contact ball bearings


mm mm mm kg N N –

40 85 16 0,339 22 400 27 000 BAQ-3809 C40 80 18 0,360 34 000 44 900 BAQ-3806 AC42 90 20 0,561 26 000 37 100 BAQ-3818 E50 80 16 0,264 31 000 33 200 BAQ-3922 BA50 90 20 0,456 34 500 46 200 BAQ-3954 AB50 90 20 0,471 26 000 37 100 BAQ-3814 C


32


Designation Bore diameter External diameter Width Weight Static capacity Dynamic capacity

– mm mm mm kg N N

BAQ-3806 AC 40 80 18 0,360 34 000 44 900

18 –0,050

40 –0,0120

80 –0,0150

Benefits•Low noise

•Low torque

•High stiffness

•High load-carrying capacity

•Low axial clearance

BAQ-3806 BC

33


•Low torque

•High stiffness



BAQ-3809 C



– mm mm mm kg N N

BAQ-3809 C 40 85 16 0,339 22 400 27 000

016 –0,06

5 ±0,15

040 –0,12

085,059 –0,022

34



– mm mm mm kg N N

BAQ-3814 C 50 90 20 0,471 26 000 37 100


•Low torque

•High stiffness



BAQ-3814 C

0 20 –0,12

050 –0,012

090 –0,012

35



– mm mm mm kg N N

BAQ-3818 42 90 20 0,561 26 000 37 100

090 –0,013

042 –0,012

020 –0,05


•Low torque

•High stiffness



BAQ-3818 E

36



– mm mm mm kg N N

BAQ-3922 BA 50 80 16 0,264 31 000 33 200

016 –0,12

050 –0,012

080 –0,013


•Low torque

•High stiffness



BAQ-3922 BA

37


•Low torque

•High stiffness



BAQ-3954 AB



– mm mm mm kg N N

BAQ-3954 AB 50 90 20 0,456 34 500 46 200

0 20 –0,12

050 –0,012

090 –0,012

38

Notes

39

Active steering bearing range

Flexible bearing


mm mm mm kg N N

36 49 8 0,030 7 500 9 950 BB1-3628 BA


40



– mm mm mm kg N N

BB1-3628 BA 36 49 8 0,030 7 500 9 950

0 7,24 –0,2

035,575 –0,01

049,075 –0,01

0 8,13 –0,1

Benefits•Very thin section

•Flexible

•Low torque

•Low noise

BB1-3628 BA

41

Steering column bearing application data list

Application data list – SCB Page 2

Min Max Under load Under misalignment Rotation speed

– – ± N yes/no r/min

Temperature °C

Torque to rotate Nm at room temp

Torque to rotate Nm at min temp

Torque to rotate Nm at max temp

Radial deflection mm under load

Axial deflection mm under load

Misalignment °

Dimensional data

Dimension Tolerance Material Wall thickness

mm ± – mm

Housing

Shaft

Acceptable bearing width

to fill out n.a

Application information

● Sketch of available space envelope (including interfacing dimensions of surrounding components)

● Bearing position: n Upper bearing n Lower bearing n 3rd bearing

● Bearing design: n ASCB n P-WSCB n DGBB

Project information

● Customer ● Platform, vehicle model

● Estimated volumes ● Target SOP and target price

42

Application data list – SCB Page 4

Durability tests Cycle Criteria

Static durability test

Rotational durability test

Environmental tests Applicable (Yes/No) Conditions

Temp cycle test

Thermal shock test

Humidity test

Salt fog test

Dust test

Application data list – SCB page 3

Min Max Under load Under misalignment Rotation speed

– – ± yes/no r/min

Axial crash load N

Assembly load N Housing / Shaft

Extraction load N Housing / Shaft

Yield load N Axial / Radial

Ultimate load N Axial / Radial

Pre-load N For ASCBs

Additional request Applicable (Yes/No) Conditions

Conductivity

NoisedB (A)

43

Rack EPAS application data list

Application information

● Sketch of application (including interfacing dimensions of surrounding components)

Rack system information

A1: Bushing position [mm]

Bushing clearance [mm]

A2: Bearing position [mm]

A3: Belt position [mm] Bushing clearance [mm]

A4: Pinion position [mm]

A5: Bushing position [mm]

Bushing clearance [mm]

A6: Total rack length [mm]

A7: Stroke [mm]

A8: Nut length [mm]

A9: Rack diameter [mm]

A10: Nut diameter [mm]

Project information

● Customer ● Platform, vehicle model

● Estimated volumes ● Target SOP and target price

Bushing Bushing

Pinion

Left tie rod Load point B

A7 (Stroke)A8 (BNA leghth)

Bearing Belt

Dir

ecti

onof

trav

el

1) Standard coordinate system

Powerpack

+ ECU

Right tie rodLoad point A

A1

A9

A2

A3

A4

A5

A6

x1)

z1)

y1)

A10

44

Ball screw

Drawing

A10: Nut diameter [mm] + tolerance [mm]

Lead [mm]

Material

Housing

Inner diameter [mm] + tolerance [mm]

Outer diameter [mm]

Material

Rack

Material

Bearing

Bearing type N DRACBB N FCBB N Other

If other:Axial clearance [mm]

Bore diameter [mm] + tolerance [mm]

Outer diameter [mm] + tolerance [mm]

Width [mm] + tolerance [mm]

Sealing N Shields N Seal N Open N Other:

Belt and pulley

A3: Belt position [mm]

Belt load [N]

Direction of load (coordinate system)

45

Drawing requested

EPAS system drawing with:

Distances between parts and interfaces and mounting situation

General dimension Please indicate in system sketch if not the standard coordinate system

Coordinate system for the whole study

Position of EPAS system in car

Housing drawing

Rack and ball nut drawing

Bearing assembly drawing

General information

Regulatory requirements

Traceability requirements

Safety critical component N Yes N No

Special parameters required N Yes N No If yes please specify:

Temperature in system for clearance and preload calculation

Maximum system temperature [°C]

Minimum system temperature [°C]

Maximum temperature-Δ between inner and outer ring

Mounting situation

Outer ring clamping force [N]

Inner ring clamping force [N]

Temperature cycle for endurance test/calcualation

Temperature [°C] Time ration [%]




46

Endurance cycle

Load case Fx Fy Fz Mx Mz Rotation Time ratio

– N N N Nm Nm r/min %

123

Special events cycle

Load case Fx Fy Fz Mx Mz Rotation

– N N N Nm Nm r/min

123

x*

z*y*

Fx

Mx

Fy

Fz Mz

Endurance cycle

Load case Frx Fry Frz Flx Fly Flz Stroke pos. Rotation Time ratio

– N N N N N N mm rpm %

123

Special events cycle

Load case Frx Fry Frz Flx Fly Flz Stroke pos. Rotation

– N N N N N N mm rpm

123

Frx

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SealsBearings and units

Lubrication systems

Mechatronics Services

�� er of Knowledge EngineeringCombining products, people, and application- specific knowledge, SKF delivers innovative solutions to equipment manufacturers and pro-duction facilities in every major industry world-wide. Having expert ise in multiple competence areas supports SKF Life Cycle Management, a proven approach to improv ing equipment reliabil-ity, 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.co�

® SKF is registered trademark of the SKF Group.

© SKF Group 2014The 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.

PU� �� · December 2014

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