INTORQ BFK471-25 Quick guide

www.intorq.com
setting the standard
www.intorq.com
INTORQ BFK471-25
Electromagnetically Released Spring-Applied Brake
Translation of the Original Operating Instructions

INTORQ | BA 14.0200 | 02/2016 2
This documentation applies to the:
Product key
Not coded: Supply voltage, hub bore hole, options
INTORQ B FK -
Product group: Brakes
Product type Spring-applied brake
Type: 471
Size: 25

INTORQ | BA 14.0200 | 02/2016 3
Identification
There is a packaging label on the package. The nameplate is glued to the outer surface of the brake.
The information in the following tables corresponds to the positions on the package label and the nameplate.
Document history
Refer to www.intorq.de for the latest version of these operating instructions.
Packaging label
Manufacturer Bar code
Type (see product key) Type number
Designation
Release voltage/holding voltage Rated torque Quantity per box
Release power/holding power Hub diameter Packaging date
Note CE mark
Nameplate
Manufacturer CE mark
Type (see product key)
Release voltage/holding voltage Release power/holding power Hub diameter
Type number Rated torque Date of manufacture
Material number Version Description
33002383 1.0 02/2016 SC First edition

INTORQ | BA 14.0200 | 02/2016 4
Contents
1 Preface and general information ...........................................................................................................................5
1.1 About these Operating Instructions ...............................................................................................................5
1.2 Terminology used ..........................................................................................................................................5
1.3 Conventions in use ........................................................................................................................................5
1.4 Abbreviations used ........................................................................................................................................6
1.5 Safety instructions and notices .....................................................................................................................7
1.6 Scope of delivery ...........................................................................................................................................8
1.7 Disposal ........................................................................................................................................................8
1.8 Drive systems ................................................................................................................................................9
1.9 Legal regulations ...........................................................................................................................................9
2 Safety instructions ...............................................................................................................................................10
2.1 General safety instructions ..........................................................................................................................10
2.2 Application as directed ................................................................................................................................11
3 Technical specifications ......................................................................................................................................12
3.1 Product description .....................................................................................................................................12
3.2 Transporting the brake ...............................................................................................................................14
3.3 Rated data ...................................................................................................................................................15
3.4 Rated data (dimensioning data) electrical data ...........................................................................................16
3.5 Switching times ...........................................................................................................................................16
3.6 Switching energy / switching frequency ......................................................................................................18
3.7 Emissions ....................................................................................................................................................19
4 Mechanical installation ........................................................................................................................................20
4.1 Important notes ...........................................................................................................................................20
4.2 Assembly .....................................................................................................................................................22
5 Electrical installation ............................................................................................................................................28
5.1 Important notes ...........................................................................................................................................28
5.2 Minimum bending radius for the brake connecting cable ...........................................................................28
5.3 Bridge-half-wave rectifier ............................................................................................................................28
5.4 Electrical connection ...................................................................................................................................29
6 Commissioning and operation ............................................................................................................................33
6.1 Important notes ...........................................................................................................................................33
6.2 Function checks before commissioning ......................................................................................................34
6.3 Brake with proximity switch .........................................................................................................................35
6.4 Commissioning ............................................................................................................................................37
6.5 During operation ..........................................................................................................................................37
7 Maintenance and repair .......................................................................................................................................38
7.1 Wear of spring-applied brakes ....................................................................................................................38
7.2 Inspections ..................................................................................................................................................39
7.3 Maintenance ................................................................................................................................................40
7.4 Spare-parts list ............................................................................................................................................44
7.5 Accessories .................................................................................................................................................45
8 Troubleshooting and fault elimination ...............................................................................................................46

Preface and general information
INTORQ | BA 14.0200 | 02/2016 5
1 Preface and general information
1.1 About these Operating Instructions
❚These Operating Instructions will help you to work safely with the spring-applied brake with electromag-
netic release. They contain safety instructions that must be followed.
❚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.
❚The Operating Instructions must always be in a complete and perfectly readable condition.
1.2 Terminology used
1.3 Conventions in use
This document uses the following styles to distinguish between different types of information:
Term In the following text used for
Spring-applied brake Electromagnetically Released Spring-Applied Brake
Drive system Drive systems with spring-applied brakes and other drive compo-
nents
Spelling of numbers Decimal separator Point The decimal point is always used.
For example: 1234.56
Symbols Page reference Reference to another page with additional
information
For example: 16 = refer to page 16
Wildcard Wildcard for options, selections
For example: BFK458- = BFK458-10
Note Important notice about ensuring smooth
operations or other key information.

Preface and general information
INTORQ | BA 14.0200 | 02/2016 6
1.4 Abbreviations used
Letter symbol Unit Designation
FRN Rated frictional 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
MANm Tightening torque of fixing screws
Mdyn Nm Braking torque at a constant speed of rotation
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
QEJ Max. permissible friction energy for one-time switching, thermal parameter
of the brake
QRJ Braking energy, friction energy
QSmax J Max. permissible friction energy for cyclic switching, depending on the
switching frequency
RNOhms Rated coil resistance at 20 °C
Sh1/h Operating frequency: the number of switching operations evenly spread
over the time unit
Shue 1/h Transition switching frequency, thermal parameter of the brake
Shmax 1/h Maximum permissible switching 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
t3ms Slipping time, operation time of the brake (according to t11) until standstill

Preface and general information
INTORQ | BA 14.0200 | 02/2016 7
1.5 Safety instructions and notices
The following icons and signal words are used in this document to indicate dangers and important safety in-
formation:
Safety instructions
Structure of safety instructions:
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
reaching the braking torque
tue s Over-excitation time
UVVoltage
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,
UNequals UL
SIGNAL WORD
Icon
Indicates the type of danger
Signal word
Characterizes the type and severity of danger
Note
Describes the danger
Possible consequences
❚List of possible consequences if the safety instructions are disregarded
Protective measure
❚List of protective measures to avoid the danger
Letter symbol Unit Designation

Preface and general information
INTORQ | BA 14.0200 | 02/2016 8
Danger level
1.6 Scope of delivery
After receipt of the delivery, check immediately whether the items delivered match the accompanying pa-
pers. INTORQ does not accept any liability for deficiencies claimed subsequently.
❚Claim visible transport damage immediately to the deliverer.
❚Claim visible deficiencies or incomplete deliveries immediately to INTORQ GmbH & Co. KG.
1.7 Disposal
The spring-applied brake consists of different types of material.
❚Recycle the metal and plastic parts.
❚Ensure professional disposal of assembled circuit boards according to the applicable environmental reg-
ulations.
DANGER
DANGER indicates a hazardous situation which, if not avoided, will result in death or serious
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 mod-
erate injury.
NOTICE
Notice about a harmful situation with possible consequences: the product itself or surrounding
objects could be damaged.

Preface and general information
INTORQ | BA 14.0200 | 02/2016 9
1.8 Drive systems
Labelling
Drive systems and components are unambiguously designated by the indications on the nameplate.
Manufacturer: INTORQ GmbH & Co. KG, Wülmser Weg 5, D-31855 Aerzen, Germany
❚The spring-applied INTORQ brake is also delivered in single modules which can then be put together by
the customer according to their requirements. The specifications – particularly the packaging label,
nameplate and type code – apply to a complete stator.
❚The labelling is not included when modules are delivered individually.
1.9 Legal regulations
Liability
❚The information, data and notes in these Operating Instructions met the state of the art at the time of
printing. Claims referring to drive systems which have already been supplied cannot be derived from this
information, illustrations and descriptions.
❚We do not accept any liability for damage and operating interference caused by:
- inappropriate use
- unauthorised modifications to the product
- improper work on or with the drive system
- operating errors
- disregarding the documentation
Warranty
❚Terms of warranty: Refer to the terms of sale and delivery for INTORQ GmbH & Co. KG.
❚Warranty claims must be made to INTORQ immediately after the defects or faults are detected.
❚The warranty is void in all cases when liability claims cannot be made.

Safety instructions
INTORQ | BA 14.0200 | 02/2016 10
2 Safety instructions
2.1 General safety instructions
❚INTORQ components:
- ... must only be used as directed.
- ... must not be used if they are noticeably damaged.
- ... must not be technically modified.
- ... must not be commissioned if they are incompletely mounted or connected.
- ... must not be operated without the required covers.
- ... can include live (current-carrying) as well as moving or rotary parts during operation according to
their degree of protection. Surfaces may be hot.
❚For INTORQ components:
- ... the documentation must always be kept at the installation site.
- ... only permitted accessories are allowed to be used.
- ... only original spare parts of the manufacturer are allowed to be used.
❚Follow all specifications and information found in the corresponding enclosed documentation.
These must be followed to maintain safe, trouble-free operations and to achieve the specified product
characteristics.
❚Only qualified, skilled personnel are permitted to work on and with INTORQ components.
According to IEC 60364 or CENELEC HD 384, qualified, skilled personnel are persons:
- ... who are familiar with the installation, mounting, commissioning, and operation of the product.
- ... who have the qualifications necessary for their occupation.
- ... who know and apply all regulations for the prevention of accidents, directives, and laws relevant
on site.
❚Risk of burns!
- Surfaces may be hot during operation! Provide for protection against accidental contact.
❚Risk of injury due to a rotating shaft!
- Wait until the motor is at standstill before you start working on the motor.
❚The friction lining and the friction surfaces must never contact oil or grease since even small amounts
reduce the braking torque considerably.
❚The brake is designed for operation under the environmental conditions that apply to IP66 protection.
Because of the numerous possibilities of using the brake, it is still necessary to check the functionality
of all mechanical components under the corresponding operating conditions.

Safety instructions
INTORQ | BA 14.0200 | 02/2016 11
2.2 Application as directed
❚INTORQ components:
- ... are intended for use in machinery and systems.
- ... must only be used for the purposes ordered and confirmed.
- ... must only be operated under the ambient conditions prescribed in these Operating Instructions.
- ... must not be operated beyond their corresponding power limits.
Any other use or excessive usage is considered improper!
Usage conditions for the INTORQ spring-applied brake
❚No explosive or aggressive atmosphere.
❚Humidity: no restrictions
❚Ambient temperature:
- Standard design:
-20 °C to +40 °C
❚At high humidity and low temperature:
- Take measures to protect the armature plate and rotor from freezing.
❚Protect the electrical connections against any contact or touching.
Check bore hole
NOTICE
In the case of strongly fluctuating temperatures/increased water condensation, drain the con-
densed water from time to time via the check hole (metal screwed cap, refer to Figure 1 and 2)
provided for this purpose.

Technical specifications
INTORQ | BA 14.0200 | 02/2016 12
3 Technical specifications
3.1 Product description
3.1.1 Important notes
Single-rotor design
Fig. 1 Design of the BFK471-25 spring-applied brake, single-rotor design
NOTICE
This brake should only be operated with the bridge-half-wave rectifier (included in delivery).
The power during the release is 440 W for 1.3 sec., then it is reduced to 110 W.
NOTICE
Due to the structural design of the stator, the air gap cannot be installed downstream.
❚When the wear limit is reached:
- in the case of the single-rotor design, the rotor must be replaced
- in the case of the double-rotor design, the "Flange complete" unit and the rotor must be
replaced.
AA
Check hole, air gap with plug screw
1 Stator, complete 4 Hub 12 Manual release
2 Armature plate 6 Flange 33 Hollow shaft end cover
3 Complete rotor 10 Six socket head cap screws, DIN EN ISO 4762 34 Plug screw
10A Four socket head cap screws, DIN EN ISO 4762
(short)
AA

Technical specifications
INTORQ | BA 14.0200 | 02/2016 13
Double-rotor design
Fig. 2 Design of the BFK471-25 spring-applied brake, double-rotor design
The spring-applied brake is designed for converting mechanical work and kinetic energy into heat energy.
Due to the static braking torque, loads can be held at standstill. Emergency braking is possible at high speed
of rotation. The wear increases as the switching energy increases (operating speeds 15).
The spring-applied brake is a disc brake with two or four friction surfaces, depending on the design. The brak-
ing torque is generated by several pressure springs with friction locking. The braking circuits are released
electromagnetically.
3.1.2 Brakes
During the braking procedure, the pressure springs use the armature plate (2) to press the rotor (3) (which
can be shifted axially on the hub (4)) against the friction surface. The asbestos-free friction linings ensure
high braking torque and low wear. The braking torque is transmitted between the hub (4) and the rotor (3)
via gear teeth.
AA
Check hole, air gap with plug screw
1 Stator, complete 4 Hub 12 Manual release
2 Armature plate 6 Flange 33 Hollow shaft end cover
3 Complete rotor 10 Six socket head cap screws, DIN EN ISO 4762 34 Plug screw
10A Six socket head cap screws, DIN EN ISO 4762
(short)

Technical specifications
INTORQ | BA 14.0200 | 02/2016 14
3.1.3 Brake release
When the brakes are applied, an air gap "sL" is present between the stator (1) and the armature plate (2). To
release the brake, the coil of the stator (1) is energised with the DC voltage provided. The resulting magnetic
flux works against the spring force to draw the armature plate (2) to the stator (1). This releases the rotor (3)
from the spring force and allows it to rotate freely
3.1.4 Project planning notes
❚The brakes are dimensioned in such a way that the given rated torques are reached safely after a short
run-in process.
❚However, since the organic friction linings used do not all have identical properties and because envi-
ronmental conditions can vary, deviations from the specified braking torques are possible. These must
be taken into account in the form of appropriate dimensioning tolerances. Increased breakaway torque
is common in particular after long downtimes in humid environments where temperatures vary.
❚If the brake is used as a pure holding brake without dynamic load, the friction lining must be reactivated
regularly.
3.2 Transporting the brake
These brakes come standard with threaded holes for attaching eye bolts according to DIN 580. The locations
of the threaded holes are shown in the following illustration. The eye bolts are not included.
Tab. 1: Positioning of the eye bolt
CAUTION
Risk of injury
Auxiliary transport materials (e.g. eye bolts or bearing plates) must be screwed in completely.
They must also be attached so that they are flat and level!
Auxiliary transport materials (e.g. eye bolts or bearing plates) should be loaded perpendicular
to their screw axis! Angled or lateral stresses reduce their load-carrying capacity! Follow the
specifications in DIN 580!
Use suitable means for carrying so that the load direction is perpendicular and a high load-
carrying capacity is ensured. Secure the carrying materials so that they cannot slip!
Positioning Threaded hold, standard eye bolt
M10, DIN 580

Technical specifications
INTORQ | BA 14.0200 | 02/2016 15
3.3 Rated data
1) Maximum speed of rotation when installed horizontally (for higher speeds, contact the manufac-
turer)
* Notice: When handling seals
Type
BFK471-25
Max. speed of
rotation 1)
Heat
class
Operating
time
Moment of
inertia
Weight
Design
nmax
[rpm]
Stator
[%]
Rotor
[kgcm2]
Hub
[kg]
Flange
[kg]
Stator
complete
[kg]
Brake
[kg]
with one rotor 1800 F 100 200 1.8 7.2 46.5 58
double rotor 200+200 2.7 23.8 75
Tab. 2: General brake characteristics
Type Air gap Rotor thickness
BFK471-25 sLN sL max min. max.
Design [mm] [mm] [mm] [mm]
with one rotor 0.5 1.5 19.1 20.0
double rotor 0.8 19.7 + 19.7
Tab. 3: Air gap / rotor thickness; monitor using the feeler gauge through the check hole
Type
BFK471-25
Outer diameter Pitch circle Fixing screws
DIN EN ISO 4762 - 8.8
Minimum thread
depth
Tightening
torque
Design [mm]

[mm] Thread [mm] [mm] MA[Nm]
with one rotor
333 278 Twelve
M10
Six M10x120 *
Four M10x30 19 48 ±10%
double rotor Six M10x160 *
Six M10x45
Tab. 4: Installation data
CAUTION
❚The minimum thread depth of the end shield must be maintained! Tab. 4.
❚If the required thread depth is not maintained, the fixing screws may run onto the root. This
has the effect that the required pre-load force is no longer established – the brake is no
longer securely fastened!
A
A

Technical specifications
INTORQ | BA 14.0200 | 02/2016 16
3.4 Rated data (dimensioning data) electrical data
3.5 Switching times
Engagement time
The transition from a brake-torque-free state to a holding-braking torque is not free of time lags.
❚The engagement times apply for DC switching with a spark suppressor.
- Spark suppressors are available for the rated voltages.
- Connect the spark suppressors in parallel to the contact. If this switching 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.
- Circuit proposals: 29
❚The engagement times are approx. 10 times longer with AC switching.
- Connection: 29
Type Voltage Power Coil resistance Current
Release
±10%
(1.3 sec.)
Holding
±10%
Brake
release
Holding Brake
release
Holding
UL[V DC] UH[V DC] PL[W] PH[W] RN± 5% []I
L[A] IH[A]
BFK471-25 205 103 440 110 96.5 2.14 1.07
360 180 294.6 1.22 0.61
Tab. 5: Coil powers of the BFK471-25
Type
BFK471-25 Rated torque Mdyn at 100 rpm Reduction of rated torque Mdyn to X [%]
Design [Nm] 1500 rpm 1800 rpm
with one rotor 750 70 % 65 %
double rotor 1500
Tab. 6: Rated torque reduction depending on the speed of rotation

Technical specifications
INTORQ | BA 14.0200 | 02/2016 17
Disengagement time
The disengagement time is the same for DC and AC switching. The specified disengagement times always
refer to control using over-excitation (i.e. current feed with UL= UN(potential difference across air gap = rated
coil voltage).
1) Measured with induced voltage limitation of -150 V DC
Fig. 3 Operating/switching times of the spring-applied brakes
Type
BFK471-25 Rated torque
Max. perm.
friction
energy
Transitional
switching
frequency
Switching times [ms] 1)
at sLN and 0.7 IN
Mdyn QEShue
Engaging
DC side1) Disengaging
Design [Nm] [J] [1/h] t11 t12 t1t2 sLN t2sLmax.
with one rotor 750 90000 16 120 200 320 350 1050
double rotor 1500 180000 8 450
Tab. 7: Friction work - switching frequency - switching times
t1Engagement time t11 Reaction delay of engagement
t2Disengagement time (up to M = 0.1 Mdyn)t
12 Rise time of the braking torque
Mdyn Braking torque at a constant speed of rotation U Voltage

Technical specifications
INTORQ | BA 14.0200 | 02/2016 18
3.6 Switching energy / switching frequency
Fig. 4 Switching energy as a function of the switching frequency
The permissible switching frequency "Shmax" depends on the amount of heat "QR" (refer to Figure 4). At a pre-
set switching frequency "Sh", the permissible amount of heat is "QSmax".
With high speeds of rotation and switching energy, the wear increases strongly, because very high temper-
atures occur at the friction surfaces for a short time.
AA
Switching energy QR[J]
B
Operating frequency S h [h-1]
I
BFK471-25 single-rotor
II
BFK471-25 double-rotor
1000 10000
10
2
10
110
3
10
4
10
4
10
5
10
2
10
10
3
S
h
[h
[h
-1
-1
]
Q
R
[J]
[J]
A
B
I
II
Shmax
Shue –
ln 1
QR
QE
---------
–



--------------------------------=
Qsmax QE1e
Shue –
Sh
-------------------
–






=

Technical specifications
INTORQ | BA 14.0200 | 02/2016 19
3.7 Emissions
Electromagnetic compatibility
If an INTORQ rectifier is used for the DC switching of the spring-applied brake: If the switching frequency
exceeds five switching operations per minute, the use of a mains filter is required.
Spark suppressors are available on request, depending on the coil voltage.
Heat
Since the brake converts kinetic energy as well as mechanical and electrical energy into heat, the surface
temperature varies considerably, depending on the operating conditions and possible heat dissipation. Un-
der unfavourable conditions, the surface temperature can reach 130 °C.
Noise
The switching noise during engagement and disengagement varies depending on the air gap, braking torque
and brake size.
Depending on the natural oscillation after installation, operating conditions and state of the friction surfaces,
the brake may squeak during braking.
Miscellaneous
The abrasion of the friction parts produces dust.
NOTICE
The user must ensure compliance with EMC Directive 2014/30/EU using appropriate controls
and switching devices.

Mechanical installation
INTORQ | BA 14.0200 | 02/2016 20
4 Mechanical installation
4.1 Important notes
4.1.1 Design of end shield and motor shaft
❚Comply with the mentioned minimum requirements regarding the end shield and the motor shaft to en-
sure a correct function of the brake.
❚The diameter of the shaft shoulder must not be greater than the tooth root diameter of the hub.
❚The form and position tolerances apply only to the materials mentioned. Contact INTORQ if you are us-
ing other materials.
❚The brake flange must be supported by the end shield across the full surface.
Design of the end shield
1) Especially near the O-rings
NOTICE
The toothed hub and screws must not be lubricated with grease or oil.
Type Minimum requirements
Material Evenness
[mm]
Axial
run-out
[mm]
Roughness1) Miscellaneous
BFK471-25 Cast
Steel < 0.08 0.08 Rzmax. 16
❚Threaded holes with minimum
thread depth 15
❚Free of grease and oil
Tab. 8: Minimum requirement for the leakproofness