INTORQ BFK557 Quick guide

INTORQ BFK557
Spring-applied brake with electromagnetic release
Translation of the Original Operating Instructions
www.kendrion.com

Document history
Material number Version Description
33008776 1.0 04/2020 SC First edition, Additional sizes: 06, 08, 10, 12
33008776 2.0 07/2020 SC Notice added to chapter 5.5, updated chapter 8.2.1 and chapter 8.3
33008776 3.0 01/2021 SC Change of name to Kendrion INTORQ, updated chapter 4.6 and
chapter 8.3
33008776 4.0 03/2022 SC Updating chapters 3.5, 4.2, 4.3, 5.1, 5.2, 5.5.2, 7.1, 8.2 and 8.3
Legal regulations
Liability
¾
The information, data and notes in these Operating Instructions are up to date at the time of printing.
Claims referring to drive systems which have already been supplied cannot be derived from this infor-
mation, illustrations and descriptions.
¾
We do not accept any liability for damage and operating interference caused by:
– inappropriate use
– unauthorized modifications to the product
– improper work on or with the product
– operating errors
– disregarding the documentation
Warranty
Notice
The warranty conditions can be found in the terms and conditions of Kendrion INTORQ
GmbH.
¾
Warranty claims must be made to Kendrion INTORQ immediately after the defects or faults are de-
tected.
¾
The warranty is void in all cases when liability claims cannot be made.
Kendrion INTORQ | BA 14.0223 | 04/2022 2

Spring-applied brakes of type BFK557-06...12
Design sizes 06-12
Product key
Product group: Brakes
Product family: Spring-applied brake
Type: 557
Size: 06, 08, 10, 12
Not specified: Standard brake (rated torque +/-tolerance)
H-version (rated torque + tolerance)
Design/type:
INTORQ B FK
Not coded: Connection voltage, hub bore diameter, options
Checking the delivery
After receipt of the delivery, check immediately whether the items delivered match the accompanying pa-
pers.
Kendrion INTORQ does not accept any liability for deficiencies claimed subsequently.
¾
Claim visible transport damage immediately to the deliverer.
¾
Claim visible defects or incompleteness of the delivery immediately to Kendrion INTORQ.
Kendrion INTORQ | BA 14.0223 | 04/2022 3

Contents
1 General information....................................................................................................................................................7
1.1 Using these Operating Instructions.......................................................................................................................7
1.2 Conventions in use ...............................................................................................................................................7
1.3 Safety instructions and notices.............................................................................................................................7
1.4 Terminology used .................................................................................................................................................8
1.5 Abbreviations used ...............................................................................................................................................9
2 Safety instructions ...................................................................................................................................................11
2.1 General safety instructions .................................................................................................................................11
2.2 Disposal..............................................................................................................................................................11
3 Product description..................................................................................................................................................12
3.1 Proper and intended usage ................................................................................................................................12
3.1.1 Standard applications.............................................................................................................................12
3.2 Layout.................................................................................................................................................................12
3.2.1 Sizes 06 to 12.........................................................................................................................................12
3.3 Function..............................................................................................................................................................13
3.4 Braking and release............................................................................................................................................13
3.5 Project planning notes ........................................................................................................................................13
3.6 Optional configuration.........................................................................................................................................14
3.6.1 Hand-release (optional)..........................................................................................................................14
3.6.2 Optional flange .......................................................................................................................................14
3.6.3 Optional friction plate..............................................................................................................................14
3.6.4 Optional cover ring .................................................................................................................................14
4 Technical specifications ..........................................................................................................................................15
4.1 Possible applications of the Kendrion INTORQ spring-applied brake ................................................................15
4.2 Characteristics....................................................................................................................................................15
4.3 Switching times...................................................................................................................................................18
4.4 Electromagnetic compatibility .............................................................................................................................19
4.5 Emissions ...........................................................................................................................................................20
4.6 Labels on product ...............................................................................................................................................20
Kendrion INTORQ | BA 14.0223 | 04/2022 4

5 Mechanical installation ............................................................................................................................................22
5.1 Design of end shield and shaft ...........................................................................................................................22
5.2 Tools...................................................................................................................................................................23
5.3 Preparing the installation ....................................................................................................................................23
5.4 Installing the hub onto the shaft..........................................................................................................................24
5.5 Mounting the brake.............................................................................................................................................25
5.5.1 Mounting the BFK557-06 to -12 .............................................................................................................25
5.5.2 Assembly of the flange...........................................................................................................................27
5.5.3 Mounting the cover ring..........................................................................................................................28
6 Electrical installation................................................................................................................................................30
6.1 Electrical connection...........................................................................................................................................30
6.1.1 AC switching at the motor – extremely delayed engagement ................................................................31
6.1.2 DC switching at the motor – fast engagement .......................................................................................32
6.1.3 AC switching at mains – delayed engagement ......................................................................................33
6.1.4 DC switching at mains – fast engagement.............................................................................................34
6.2 Minimum bending radius for the brake connection cable ...................................................................................35
6.3 Bridge/half-wave rectifier (optional) ....................................................................................................................35
6.3.1 Assignment: Bridge/half-wave rectifier – brake size...............................................................................35
6.3.2 Technical specifications .........................................................................................................................36
6.3.3 Reduced switch-off times .......................................................................................................................36
6.3.4 Permissible current load at ambient temperature...................................................................................37
7 Commissioning and operation ................................................................................................................................38
7.1 Possible applications of the Kendrion INTORQ spring-applied brake ................................................................38
7.2 Function checks before initial commissioning.....................................................................................................39
7.2.1 Function check of the brake ...................................................................................................................39
7.2.2 Release / voltage control........................................................................................................................39
7.2.3 Testing the hand-release functionality....................................................................................................40
7.3 Commissioning ...................................................................................................................................................41
7.4 Operation............................................................................................................................................................41
Kendrion INTORQ | BA 14.0223 | 04/2022 5

8 Maintenance and repair............................................................................................................................................42
8.1 Wear of spring-applied brakes............................................................................................................................42
8.2 Inspections..........................................................................................................................................................43
8.2.1 Maintenance intervals ............................................................................................................................43
8.3 Maintenance .......................................................................................................................................................43
8.3.1 Checking the components......................................................................................................................44
8.3.2 Checking the air gap ..............................................................................................................................44
8.3.3 Release / voltage....................................................................................................................................44
8.3.4 Brake replacement .................................................................................................................................45
8.4 Spare parts list....................................................................................................................................................46
9 Troubleshooting and fault elimination....................................................................................................................48
Kendrion INTORQ | BA 14.0223 | 04/2022 6

General information
Kendrion INTORQ | BA 14.0223 | 04/2022 7
1 General information
1.1 Using these Operating Instructions
¾
These Operating Instructions will help you to work safely with the spring-applied brake with electro-
magnetic release. They contain safety instructions that must be followed.
¾
All persons working on or with electromagnetically released spring-applied brakes must have the Oper-
ating Instructions available and observe the information and notes relevant for them.
¾
The Operating Instructions must always be in a complete and perfectly readable condition.
1.2 Conventions in use
This document uses the following styles to distinguish between different types of information:
Spelling of numbers Decimal separator Point The decimal point is always used. For ex-
ample: 1234.56
Page reference Underlined, red _____
Reference to another page with additional
information
For example: Using these Operating In-
structions,Page7
Symbols
Wildcard □
Wildcard (placeholder) for options or selec-
tion details
For example: BFK557-□□ = BFK557-10
Notice Important notice about ensuring smooth op-
erations or other key information.
1.3 Safety instructions and notices
The following icons and signal words are used in this document to indicate dangers and important safety
information:

General information
Kendrion INTORQ | BA 14.0223 | 04/2022 8
Structure of safety notices:
CAUTION
Icon
Indicates the type of danger
Signal word
Characterizes the type and severity of danger.
Notice text
Describes the danger.
Possible consequences
List of possible consequences if the safety notices are disregarded.
Protective measures
List of protective measures required to avoid the danger.
Danger level
DANGER
DANGER indicates a hazardous situation which, if not avoided, will result in death or seri-
ous injury.
WARNING
WARNING indicates a potentially hazardous situation which, if not avoided, could result in
death or serious injury.
CAUTION
CAUTION indicates a hazardous situation which, if not avoided, could result in minor or
moderate injury.
NOTICE
Notice about a harmful situation with possible consequences: the product itself or sur-
rounding objects could be damaged.
1.4 Terminology used
Term In the following text used for
Spring-applied brake Spring-applied brake with electromagnetic release
Drive system Drive systems with spring-applied brakes and other drive compo-
nents

General information
Kendrion INTORQ | BA 14.0223 | 04/2022 9
1.5 Abbreviations used
Letter symbol Unit Designation
FRN Rated frictional force
F N Spring force
I A Current
IHA Holding current, at 20 °C and holding voltage
ILA Release current, at 20 °C and release voltage
INA Rated current, at 20 °C and rated voltage
M4Nm Torque that can be transmitted without slippage occurring (DIN VDE 0580)
MANm Tightening torque of fastening screws
Mdyn Nm Average torque from initial speed to standstill
MKNm Rated torque of the brake, rated value at a relative speed of rotation of
100 rpm
nmax rpm Maximum occurring speed of rotation during the slipping time t3
PHW Coil power during holding, after voltage change-over and 20 °C
PLW Coil power during release, before voltage change-over and 20 °C
PNW Rated coil power, at rated voltage and 20 °C
Q J Quantity of heat/energy
QEJMax. permissible friction energy for one-time switching, thermal parameter of
the brake
QRJ Braking energy, friction energy
QSmax JMaximally permissible friction energy for cyclic switching, depending on the
operating frequency
RNOhms Rated coil resistance at 20 °C
Rzμm Averaged surface roughness
Sh1/h Operating frequency: the number of switching operations evenly distributed
over the time unit
Shue 1/h Transition operating frequency, thermal parameter of the brake
Shmax 1/h Maximum permissible operating frequency, depending on the friction energy
per switching operation
sLmm Air gap: the lift of the armature plate while the brake is switched
sLN mm Rated air gap
sLmin mm Minimum air gap
sLmax mm Maximum air gap
t1ms Engagement time, sum of the delay time and braking torque: rise time
t1 = t11 + t12
t2ms Disengagement time, time from switching the stator until reaching 0.1 Mdyn

General information
Kendrion INTORQ | BA 14.0223 | 04/2022 10
Letter symbol Unit Designation
t3ms Slipping time, operation time of the brake (according to t11) until standstill
t11 ms Delay during engagement (time from switching off the supply voltage to the
beginning of the torque rise)
t12 ms Rise time of the braking torque, time from the start of torque rise until reach-
ing the braking torque
tue s Over-excitation period
U V Voltage
UHV DC Holding voltage, after voltage change-over
ULV DC Release voltage, before voltage change-over
UNV DC Rated coil voltage; in the case of brakes requiring a voltage change-over,
UN equals UL

Safety instructions
Kendrion INTORQ | BA 14.0223 | 04/2022 11
2 Safety instructions
2.1 General safety instructions
¾
Never operate Kendrion INTORQ components when you notice they are damaged.
¾
Never make any technical changes to Kendrion INTORQ components.
¾
Never operate Kendrion INTORQ components when they are incompletely mounted or incompletely
connected.
¾
Never operate Kendrion INTORQ components without their required covers.
¾
Only use accessories that have been approved by Kendrion INTORQ.
¾
Only use original spare parts from the manufacturer.
Keep the following in mind during the initial commissioning and during operation:
¾
Depending on the degree of protection, Kendrion INTORQ components may have both live (voltage
carrying), moving and rotating parts. Such components require appropriate safety mechanisms.
¾
Surfaces can become hot during operation. Take appropriate safety measures (to ensure contact/
touch protection).
¾
Follow all specifications and information found in the Operating Instructions and the corresponding
documentation. These must be followed to maintain safe, trouble-free operations and to achieve the
specified product characteristics.
¾
The installation, maintenance and operation of Kendrion INTORQ components may only be carried out
by qualified personnel. According to IEC 60364 and CENELEC HD 384, skilled personnel must be
qualified in the following areas:
– Familiarity and experience with the installation, assembly, commissioning and operation of the
product.
– Specialist qualifications for the specific field of activity.
– Skilled personnel must know and apply all regulations for the prevention of accidents, directives,
and laws relevant on site.
2.2 Disposal
The Kendrion INTORQ components are made of various differing materials.
¾
Recycle metals and plastics.
¾
Ensure professional disposal of assembled PCBs according to the applicable environmental regula-
tions.

Product description
Kendrion INTORQ | BA 14.0223 | 04/2022 12
3 Product description
3.1 Proper and intended usage
3.1.1 Standard applications
Kendrion INTORQ components are intended for use in machinery and facilities. They may only be used
for purposes as specified in the order and confirmed by Kendrion INTORQ. The Kendrion INTORQ com-
ponents may only be operated under the conditions specified in these Operating Instructions. They may
never be operated beyond their specified performance limits. The technical specifications (refer to Techni-
cal specifications,Page15) must be followed to comply with the proper and intended usage. Any other
usage is consider improper and prohibited.
3.2 Layout
This chapter describes the design and functionality of the INTORQ BFK557 spring-applied brake.
3.2.1 Sizes 06 to 12
A
BCD
E
F
G
HI
Fig.1: Design of a INTORQ spring-applied brake BFK557-06 to 12: Complete stator + rotor + friction plate
AStator BSocket-head cap screw CArmature plate
DAssembly lock (rubber ring) ERotor FHub
GFriction plate (optional) HSleeve bolt ICoil

Product description
Kendrion INTORQ | BA 14.0223 | 04/2022 13
3.3 Function
This brake is an electrically releasable spring-applied brake with a rotating brake disk (rotor) that is
equipped on both sides with friction linings. In its de-energized state, the rotor is clamped with braking
force applied by pressure springs between the armature plate and a counter friction surface. This corre-
sponds to a fail-safe functionality.
The brake torque applied to the rotor is transferred to the input shaft via a hub that has axial gear teeth.
The brake can be used as a holding brake and for emergency stops.
The asbestos-free friction linings ensure a safe braking torque and low wear.
To release the brake, the armature plate is released electromagnetically from the rotor. The rotor, shifted
axially and balanced by the spring force, can rotate freely.
3.4 Braking and release
During the braking procedure, the pressure springs use the armature plate to press the rotor (which can
be shifted axially on the hub) against the friction surface. The braking torque is transmitted between the
hub and the rotor via gear teeth.
When the brakes are applied, an air gap (sL) is present between the stator and the armature plate. To re-
lease the brake, the coil of the stator is energized with the DC voltage provided. The resulting magnetic
flux works against the spring force to draw the armature plate to the stator. This releases the rotor from the
spring force and allows it to rotate freely.
3.5 Project planning notes
¾
When designing a brake for specific applications, torque tolerances, the limiting speeds of the rotors,
the thermal resistance of the brake, and the effect of environmental influences must all be taken into
account.
¾
The brakes are dimensioned in such a way that the specified rated torques are reached safely after a
short run-in period.
¾
Increased breakaway torque can occur as a result of long standstill periods in humid environments with
varying temperatures.
¾
Since the material properties of the friction linings are subject to fluctuations and as a result of different
environmental conditions, deviations from the specified braking torque are possible. This has to be
taken into account by appropriate dimensioning of the tolerances. These must be taken into account in
the form of appropriate dimensioning tolerances. Increased breakaway torque can occur in particular
as an result of long standstill periods in humid environments with varying temperatures.
¾
If the brake is used as a pure holding brake without dynamic load, the friction lining must be reacti-
vated regularly.

Product description
Kendrion INTORQ | BA 14.0223 | 04/2022 14
3.6 Optional configuration
3.6.1 Hand-release (optional)
To temporarily release the brake when there is no electricity available, a hand-release version is available
as an option.
3.6.2 Optional flange
If no suitable friction surface is available, an optional flange can be delivered.
3.6.3 Optional friction plate
A friction plate can be used if there is an available flat surface that is not suitable for use as a friction sur-
face.
3.6.4 Optional cover ring
The cover ring prevents most dust and moisture from escaping or penetrating into the brake compartment.

Technical specifications
Kendrion INTORQ | BA 14.0223 | 04/2022 15
4 Technical specifications
4.1 Possible applications of the Kendrion INTORQ spring-applied brake
¾
Degree of protection:
– The brake is designed for operation under the operating conditions that apply to IP54 protection.
Because of the numerous possibilities of using the brake, it is still necessary to check the function-
ality of all mechanical components under the corresponding operating conditions.
¾
Ambient temperature:
– -20 °C to +50 °C (Standard)
4.2 Characteristics
Size Brake torque Max. permissible
switching energy
Air gap Moment of in-
ertia of rotor
Weight of
brake
Rated value at
Δn=100 rpm
Rated value of
the H-version
MKMKQESLN
1) SLmax JRotor m
[Nm] [Nm] [J] [mm] [mm] [kg cm2] [kg]
06
2.5 2
3000 0.2 -0.1
0.5
0.130 0.863 2.5 0.4
5 4 0.3
08
5 4
7500 0.2 -0.1
0.5
0.450 1.347 5 0.4
10 8 0.3
10
10 8
12000 0.25 -0.1
0.6
2.0 2.5813 10 0.5
20 16 0.35
12
20 16
24000 0.3 -0.1
0.65
4.5 3.7727 21 0.55
40 32 0.4
Tab.1: General data
1) The default (as delivered) air gap results from the sum tolerances of the individual components. These operating
times are specified for usage of Kendrion INTORQ bridge/half-wave rectifiers and coils with a connection voltage of
205 V DC at sLN and 0.7*IN.

Technical specifications
Kendrion INTORQ | BA 14.0223 | 04/2022 16
Size Outer diameter Screw hole circle Minimum thread
depth
Tightening torque
Screws Lever
Diameter (Ø) Thread1) MAMA
[mm] [mm] [mm] [Nm] [Nm]
06 83 72 3x M4 11 3.0 2.8
08 103 90 3x M5 5.9
10 127 112 3x M6 14 10.1 4.8
12 147 132
Tab.2: Mounting data
1) Fastening screws (socket-head cap screws according to DIN EN ISO 4762) are included in the scope of delivery
CAUTION
Functional incapacity of the brake
It is very important to comply with the minimum thread depth of the end shield (refer to the
table Mounting data,Page16).
If the required thread depth is not maintained, the fastening screws may run onto the
thread root. This has the effect that the required pre-load force is no longer established –
the brake is no longer securely fastened!
The material of the end shield must have a tensile strength of Rm > 250 N/mm2 !
Size Rated brake torque at Δn=100 rpm Braking torque at Δn0Max. rotation
speed Δn0max
MK1500 3000 Max.
[%] [%] [%] [%] [rpm]
06
100
87 80 74 6000
08 85 78
73
5000
10 83 76 4000
12 81 74 3600
Tab.3: Brake torques

Technical specifications
Kendrion INTORQ | BA 14.0223 | 04/2022 17
Size Electrical power Rated voltage Rated current Coil resistance
PNUNINRN
[W] [V] [A] [Ω] ±8%
06
20 24 0.83 28.8
19.3 103 0.187 550
18.7 127 0.147 863
19.9 180 0.111 1620
20 205 0.098 2101
18.7 215 0.087 2472
20 250 0.08 3125
08
23 24 0.958 25.04
24 103 0.233 442
23 127 0.181 701
23.5 180 0.131 1379
24.5 205 0.12 1715
23 215 0.107 2010
23.5 250 0.094 2660
10
24 24 1.0 24.0
103 0.233 442
25 127 0.197 645
27 180 0.15 1200
205 0.132 1556
25 215 0.116 1849
26 250 0.104 2404
12
38 24 1.583 15.2
103 0.369 279
40 127 0.315 403
38 180 0.211 853
40
205 0.195 1051
215 0.186 1156
250 0.160 1563
Tab.4: Coil data

Technical specifications
Kendrion INTORQ | BA 14.0223 | 04/2022 18
4.3 Switching times
The operating times listed here are guide values which apply to DC switching with rated air gap sLN, warm
coil and standard characteristic torque. The given operating times are average values and subject to varia-
tions. The engagement time t1 is approximately 8 to 10 times longer for AC switching.
t
t
M
t2
t12
t11
t1
Mdyn
U
0.1Mdyn
Fig.2: Operating/switching times of the spring-applied brakes
t1Engagement time t11 Delay time during engagement
t2Disengagement time (up to M = 0.1 Mdyn)t12 Rise time of the braking torque
Mdyn Braking torque at a constant speed of rotation UVoltage
Engagement time
The transition from a brake-torque-free state to a holding-braking torque is not free of time lags.
For emergency braking, short engagement times for the brake are absolutely essential. The DC-side
switching in connection with a suitable spark suppressor must therefore be provided.
Engagement time for AC-side switching: The engagement time is significantly longer (approx. 10 times
longer).
NOTICE
Connect the spark suppressors in parallel to the contact. If this is not admissible for safety
reasons (e.g. with hoists and lifts), the spark suppressor can also be connected in parallel
to the brake coil.
¾
If the drive system is operated with a frequency inverter so that the brake will not be de-energized be-
fore the motor is at standstill, AC switching is also possible (not applicable to emergency braking).
¾
The specified engagement times are valid for DC switching with a spark suppressor.
– Circuit proposals: refer to DC switching at mains – fast engagement,Page34.
Notice
Spark suppressors are available for the rated voltages.

Technical specifications
Kendrion INTORQ | BA 14.0223 | 04/2022 19
Disengagement time
The disengagement time is the same for DC-side and AC-side switching. The specified disengagement
times always refer to control using Kendrion INTORQ rectifiers and rated voltage.
Size Rated torque Max. permissible
switching energy
Operating times 2)
at 100 rpm H-version DC-side engagement Disengaging
MKMKQE
1) t11 t12 t1t2
[Nm] [Nm] [J] [ms] [ms] [ms] [ms]
06
2.5 2
3000
20 13 33 30
3 2.5 16 13 29 40
5 4 10 13 23 60
08
5 4
7500
30 16 46 40
7 5 25 16 41 50
10 8 15 16 31 65
10
10 8
12000
50 19 69 70
13 10 40 19 59 90
20 16 25 19 44 120
12
20 16
24000
55 25 80 100
27 21 45 25 70 130
40 32 30 25 55 170
Tab.5: Switching energy - operating frequency - operating times
1) The maximum permissible friction energy QE relates to the standard friction lining.
2) These operating times are specified for usage of Kendrion INTORQ bridge/half-wave rectifiers and coils with a con-
nection voltage of 205 V DC at sLN and 0.7 IN.
4.4 Electromagnetic compatibility
Notice
The user must ensure compliance with EMC Directive 2014/30/EC using appropriate controls
and switching devices.
NOTICE
If a Kendrion INTORQ rectifier is used for the DC switching of the spring-applied brake
and if the switching frequency exceeds five switching operations per minute, the use of a
mains filter is required.
If the spring-applied brake uses a rectifier of another manufacturer for the switching, it
may become necessary to connect a spark suppressor in parallel with the AC voltage.
Spark suppressors are available on request, depending on the coil voltage.

Technical specifications
Kendrion INTORQ | BA 14.0223 | 04/2022 20
4.5 Emissions
Heat
Since the brake converts kinetic energy and electrical energy into heat, the surface temperature varies
considerably, depending on the operating conditions and possible heat dissipation. A surface temperature
of 130 °C may be reached under unfavorable conditions.
Noise
The loudness of the switching noise during engaging and disengaging depends on the air gap "sL" and the
brake size.
Depending on the natural oscillation after installation, operating conditions and the state of the friction sur-
faces, the brake may squeak during braking.
4.6 Labels on product
There is a packaging label on the package. The name plate is glued to the lateral surface of the brake.
Fig.3: Packaging label
Kendrion INTORQ Manufacturer
33007925 ID number
BFK557-10 Type (refer to Product key,Page3 )
Bar code
SPRING-APPLIED BRAKE Designation of the product family
205 V DC Rated voltage
16 NM Rated torque
1 pc. Qty. per box
27 W Rated power
20 H7 Hub diameter
14.12.20 Packaging date
Anti-rust packaging: keep friction surface free of
grease! Addition
CE mark