Actuators are the last link in the long chain that generates the brake force which ultimately brings the vehicle to a halt. When configuring its systems, Knorr-Bremse can draw on an extensive portfolio of components for all vehicle categories.
Low-Maintenance Operation and Lightweight Designs
Our actuators are always adapted to the vehicle’s specific interfaces so that they can execute the braking command from the driver’s cab on the vehicle’s wheels or axles. The actuator portfolio includes compact, lightweight brake caliper units 'WheelAct / AxleAct' and block brake units for a wide range of climatic conditions and application scenarios. Low-maintenance, high-performance hydraulic brake force actuators can be installed in extremely small spaces. Knorr-Bremse always adapts its units to the specific vehicle interfaces.
Contact
Sales Rail Vehicle Systems Knorr-Bremse Systeme für Schienenfahrzeuge GmbH
80809 München
Deutschland - Germany
sales.sfs@knorr-bremse.com
Track Brakes: Electromagnetic and Eddy-current Brakes 'EddyAct'
Electromagnetic and eddy-current track brakes 'EddyAct' are employed when the brake force needs to be applied independently of the wheel-rail contact. In electromagnetic track brakes 'MagnetAct', the brake force is generated by magnets with an electrical current running through them. Braking is achieved through the adhesion between the magnet and the track and the brake and the track.
In eddy-current brakes 'EddyAct', braking is achieved without relying on friction at all. These brakes are the ideal complement to pneumatic friction brakes, especially on high-speed trains.
Brake Actuation — Product Portfolio
Knorr-Bremse offers a comprehensive and modular range of brake actuators for all rail vehicle segments — from light rail trams and metros to intercity trains, high-speed trains, locomotives and freight wagons. All products are designed for minimum life cycle costs, long overhaul intervals and the highest operational reliability under extreme conditions.
The portfolio covers all relevant braking principles: pneumatic disc brakes, pneumatic tread brakes, hydraulic calipers, magnetic track brakes, eddy current linear brakes and the fully digital electromechanical brake system. Products can be combined within a single vehicle to form a complete, optimised braking system.
WheelAct / AxleAct — Brake Caliper Units
All vehicle types
Depending on the application, Knorr-Bremse conventional WheelAct Classic / AxleAct Classic or WheelAct Compact / AxleAct Compact brake calipers can be used. Both types are highly modularized to match any application, mounting space and operational conditions. This equipment incorporates a proven robust design delivering highest availability and low life-cycle costs. Compact types deliver 33 % reduced LCC through 8–10 year overhaul intervals, sealed maintenance-free bearings and the new BasicAct cylinder. All Compact types are validated for −60 °C.
- WZT (AxleAct Compact): 110 kN service, 60 kN spring PB, 110 kN hand PB, 60 kg, 305 mm width
- RZKT (WheelAct Compact): 50 kN service, 45 kN spring PB, 85 kN hand PB, 68 kg, 305 mm width
- RZT (WheelAct Compact): 90 kN service, 60 kN spring PB, 90 kN hand PB, 84 kg, 348 mm width
- All types: ±20 mm lateral movement – optional: spring PB, hand PB, SafePark®, status indicator, valves
- BasicAct Cylinder: 25 kN at 4.5 bar – saves 10 kg vs U-Cylinder (spring PB)
MagnetAct — Magnetic Track Brake
Light Rail / Metro / Urban Solutions / Tram-Train / High-Speed / Intercity / Regional
Magnetic track brakes apply brake force directly onto the rail. Track brakes from Knorr-Bremse offer high performance and reliability. Extensive in-service operation around the world is proof of the technological leadership of Knorr-Bremse. Available in three variants — Rigid (106×115×1000 mm, 75 kg/m, 72 kN/m), Flex Compact (115×115×1000 mm, 75 kg/m, 65 kN/m) and Flex (130×136×1052 mm, 125 kg/m, 90 kN/m):
- Rigid: Light Rail · Metro · Urban Solutions
- Flex Compact: Light Rail · Metro · Urban Solutions · Tram-Train
- Flex:High-speed trains · Intercity passenger coaches · Regional commuter trains
Light Weight Caliper with SafePark®
Metro / Regional / Intercity
The newly designed conventional brake caliper unit WheelAct Classic / AxleAct Classic combines the benefits of the SafePark® parking brake cylinder with lightweight design. The result is a brake caliper unit with improved functionality and significantly reduced weight and installation space, but with identical interfaces to the bogie and service-proven robust design principles. Weight reduction of 33 % (service brake: 73 kg → 53 kg; parking brake: 95 kg → 60 kg). Over the service life of a typical metro application, each caliper saves 10 MWh of energy and 24 % of total lifecycle CO₂ compared to the standard caliper.
- LCA: Standard 100 % → Light Weight 76.4 % total impact
- Manufacturing: 54.9 % → 53.0 % · Use phase: 44.5 % → 23.1 % · Recycling: 0.6 % → 0.3 %
- SafePark®: no superposition of service and parking brake
- Two-piece pull rod · poka-yoke locking mechanism · lightweight caliper body
TreadAct — Tread Brake Units
Two product lines covering the full range from passenger to freight applications.
TreadAct Compact (Type PEC7):
Air-powered brake for rail vehicles comprising brake cylinder, transmission mechanism and automatic slack adjuster for the tightest installation spaces. Available rigid or flexible, 95 % constant efficiency, 8–10 year overhaul interval, −60 °C rated. Block force: up to 60 kN service / 45 kN parking, high variation of internal ratio from 2.0 to 5.5, compatible with UIC and AAR brake blocks.
TreadAct Freight:
The compact freight car brake as a member of the TreadAct Freight family makes the operation of freight cars increasingly economical and efficient. Push brake with two single-acting slack adjusters. Vibration-damped suspension (steel-rubber-steel). Y25-bogie compatible. 12–15 year overhaul interval. Block force: 38 kN service / min. 28 kN hand parking brake. Weight: ~225 kg (BG version) / ~257 kg (BGU version) / ~282 kg (BGU version + hand PB). Adjusting capacity 205 mm, lateral movement ±20 mm.
EddyAct — Linear Eddy Current Brake
High Speed / Intercity / Regional
Eddy current brakes create brake force independent of the adhesion between wheel and rail, similar to magnetic track brakes. Knorr-Bremse's EddyAct offers enhanced safety levels and economic advantages. The system is completely independent of the track conditions and brake force remains constant, even at high speeds.
- Independent of track conditions and the wheel-rail adhesion
- Wear-free, due to no mechanical contact
- No impact on TSI infrastructure
- Controllable brake force · High brake force at high speed
- Additionally usable as service brake · Noise-free, odorless and brake dust-free
- Standard dimensions: 130×269×1540 mm · Weight: 900 kg per unit
- Brake force at 200 km/h: 21 kN per unit · Power requirement: max. 86 kW per unit
HydroAct — Hydraulic Brake Calipers
Light Rail / Metro / Monorail / People Mover
Knorr-Bremse's broad range of HydroAct hydraulic brake calipers is suitable for a wide variety of rail vehicles and requirements. Their robust design ensures they are protected against harsh environmental conditions. All HydroAct calipers feature automatic wear compensation and are maintenance-friendly – even when installed in very confined spaces.
- HC1P50: Lever, floating · 100 kN · 100 mm disc · 60 kg
- HC1P32: Lever, floating · 64 kN · 60 mm disc · 35 kg
- WZ80HZ45PS80: Unit caliper · 90 kN · 90 mm disc · 115 kg
- HSC1P10N: Floating frame · 20 kN · 45 mm disc · 15 kg
- HSE1A30: Active elastic mount · 60 kN · 60 mm disc · 37 kg
- HF2A15: Fixed active · 60 kN · 60 mm disc · 17 kg
EMB System — Electromechanical Brake
All vehicle types / Future platform
The Knorr-Bremse digital-electromechanical braking system (EMB system) is a paradigm shift in the fundamental principles of braking in rail vehicles. Unlike today's pneumatic or hydraulic braking systems the EMB system uses advanced brake-by-wire technology to transmit braking signals and generate brake force. Thereby it sets new standards of efficiency, reliability, and performance.
- Brake-by-wire: purely electrical generation and transfer of braking signal and energy
- Active system: system control in all modes incl. backup without necessity of mechanical or hydraulic element
- Complete system: provides brake control, brake energy and brake actuation
- No compressed air · no hydraulics · no mechanical transmission elements
- Cybersecurity: according to the state of the art
- Central enabler for airless train · TSI-conformity
Brake caliper units for axle- and wheel-mounted brake discs
Freight Cars | High-Speed Trains | Light Rail Vehicles | Locomotives |
Metros | Passenger Coaches | Regional and Commuter Trains
WheelAct / AxleAct
Depending on the application, Knorr-Bremse WheelAct Classic / AxleAct Classic or WheelAct Compact / AxleAct Compact brake calipers can be used. Both types are highly modularized to match any application, mounting space and operational conditions.
This equipment incorporates a proven robust design delivering highest availability and low life-cycle costs.
WheelAct Classic / AxleAct Classic with Hangers
- For axle- and wheel-mounted brake discs
- Service proven for many decades
- Wide variety of cylinder variants
BasicAct Cylinder
- Compact Cylinder combines advantages of proven Knorr-Bremse U-Cylinder and D-Cylinder
- Weight saving of 10 kg (spring parking brake) and 6 kg (service brake) compared to U-Cylinder
- High spring parking brake force of 25 kN (at 4.5 bar) due to internal lever mechanism
- Less installation space
- Enlarged overhaul period
Modular design with optional features
- spring-operated, pneumatic released parking brake
- hand-operated parking brake (hand wheel)
- SafePark function available
- electrical indication of brake status
- pneumatic valves for various functions
WheelAct Compact / AxleAct Compact
Cost-effective single-point interface models for fast and easy bogie assembly. Highly compact design offering many advantages in weight, space, noise emissions and 33% reduced LCC because of increased overhaul period. Suitable for use in combination with either a hand brake or a spring-operated parking brake.
WheelAct Compact (Type RZT) and AxleAct Compact (Type WZT) are further developments of the service-proven Knorr-Bremse standard products WheelAct Compact (Type RZS) and AxleAct Compact (Type WZK), with optimized robustness and overhaul period.
Technical Data
WZT (AxleAct Compact) – Axle-mounted
- Total pad force, service brake: 110 kN
- Total pad force, spring-operated parking brake: 60 kN (4.8 bar)
- Total pad force, hand brake: 110 kN
- Lateral axle movement: +/- 25 mm
- Width: 305 mm
- Weight: 60 kg
RZKT (WheelAct Compact) – Low forces, wheel-mounted
- Total pad force, service brake: 50 kN
- Total pad force, spring-operated parking brake: 45 kN (4.8 bar)
- Total pad force, hand brake: 85 kN
- Lateral axle movement: +/- 25 mm
- Width: 305 mm
- Weight: 68 kg
RZT (XS, S, M, L) (WheelAct Compact) – High forces, wheel-mounted
- Total pad force, service brake: 90 kN
- Total pad force, spring-operated parking brake: 60 kN (4.5 bar)
- Total pad force, hand brake: 90 kN
- Lateral axle movement: +/- 25 mm
- Width: 348 mm
- Weight: 84 kg
Advantages
- Allows maximum lateral movement and tilting of the wheelset without usage constraints
- Standard interface to bogie
- Maximum brake force of service brake adjustable by changing the diaphragm cylinder
- Installation space independent of brake force
- Superposition of brake forces in failure cases admissible
- Robust design for very harsh environmental conditions (ice, sand, low temperature -60 °C)
- Overhaul period of 8 to 10 years (depending on environmental conditions)
- Sealed bearings for less wear, less noise and low maintenance
Modular design with optional features
- spring-operated, pneumatic released parking brake
- hand-operated parking brake (hand wheel)
- SafePark function available
- electrical indication of brake status
- pneumatic valves for various functions
Light Weight Caliper with SafePark® — WheelAct / AxleAct Classic
Light Weight Caliper with SafePark®
The newly designed conventional brake caliper unit WheelAct Classic / AxleAct Classic combines the benefits of the SafePark® parking brake cylinder with lightweight design. The result is a brake caliper unit with improved functionality and significantly reduced weight and installation space, but with identical interfaces to the bogie and service-proven robust design principles (e.g. suspension, bushing design, etc.).
Key features
- Light caliper design
- SafePark® cylinder
- Two-piece pull rod
- Robust locking mechanism
Advantages
- Less installation space in the bogie
- No superposition of service and parking brake
- SafePark® suitable for all brake caliper units
- Reduction of weight, especially together with new light weight caliper design:
- Service brake from 73 kg to 53 kg
- Parking brake from 95 kg to 60 kg
Design features
Light Weight Caliper
- Weight reduction
Two-piece pull rod
- Weight reduction
- Simplified production
Locking mechanism
- Poka-yoke robustness
- Stone blasting protection
SafePark® cylinder
- No superposition
- Weight and space reduction
- Less vibration loads
Life-Cycle Assessment – focus product carbon footprint
Light Weight Caliper saves 24% CO2 emissions during its lifetime compared to the standard conventional caliper
- Total: Standard conventional caliper 100.0 % — Light Weight Caliper 76.4 %
- Manufacturing and component production: 44.5 % — 23.1 %
- Use phase: 54.9 % — 53.0 %
- Recycling and end of life: 0.6 % — 0.3 %
- Use phase only contains raw material consumption within overhaul period
- Weight reduction of 33% provides further energy and CO2-savings in the use phase of a train, i. e. 10 MWh per brake caliper during the lifetime of a typical metro application
MagnetAct — Magnetic Track Brake
Magnetic track brakes apply brake force directly onto the rail. Track brakes from Knorr-Bremse offer high performance and reliability. Extensive in-service operation around the world is proof of the technological leadership of Knorr-Bremse
MagnetAct Rigid
MagnetAct Rigid is the most powerful rigid magnet for urban line vehicles due to its improved size-to-performance ratio. The new generation is lighter, lower and more efficient..
MagnetAct Rigid is the most powerful rigid magnet for urban line vehicles due to its improved size-to-performance ratio. The new generation is lighter, lower and more efficient.
Applications
- Light Rail · Metros · Urban Solutions
Technical Data
- Standard dimensions: 106x115x1000 mm
- Weight: 75 kg/m
- Attractive force: 72 kN/m
MagnetAct Flex Compact
MagnetAct Flex Compact is the most powerful articulated magnet for urban line vehicles. Thanks to its compact design, it fits into any streetcar and delivers maximum brake force. In Low-Suspension configuration as standard, and available for Tram-Trains with High-Low Suspension.
Applications
- Light Rail · Metros · Urban Solutions · Tram-Train
Technical Data
- Standard dimensions: 115x115x1000 mm
- Weight: 75 kg/m
- Attractive force: 65 kN/m
MagnetAct Flex
MagnetAct Flex is the solution for mainline vehicles. Knorr-Bremse offers two variants for this purpose: a lightweight version and a version with increased performance for maximum brake force requirements.
Applications
- High-speed · Intercity · Regional
Technical Data
- Standard dimensions: 130x136x1052 mm
- Weight: 125 kg/m
- Attractive force: 90 kN/m
TreadAct — Tread Brake Units
The TreadAct family covers pneumatic tread brake units for passenger and freight applications. Both product lines share a design philosophy of low weight, long overhaul intervals and maintenance-free sealed bearings — while being optimised for their respective operating environments.
TreadAct Compact
Tread brake unit
The tread brake unit TreadAct Compact is a air-powered brake for rail vehicles comprising brake cylinder, transmission mechanism and automatic slack adjuster. Being compact and space-saving, they can be installed even in bogies with very narrow space restrictions. Depending on the application Knorr-Bremse offers rigid or flexible tread brake units. Both types are highly modularized to match any application, mounting space and operational conditions. This equipment incorporates a proven robust design delivering highest availability and low life-cycle costs.
Customer benefits
- Compact and modular design
- Preassembled and ready to install
- Constant high efficiency of 95%
- Weight-optimized
- Overhaul period of 8 to 10 years (depending on environmental conditions)
- Low noise because of sealed bearings
Applications
- Locomotives
- Metros
- Regional & commuter trains
- High-speed trains
Key features
- Standard interface to bogie
- Installation space independent of brake force
- Robust design for very harsh environmental conditions (ice, sand, low temperature -60 °C)
- Sealed bearings for less wear, less noise, low maintenance and longer overhaul intervals
- Superposition of brake forces in failure cases admissible
Modular design with optional features:
- Spring-operated, pneumatically released parking brake
- Hand-operated parking brake (hand wheel)
- Suitable for UIC, AAR or other brake block types
- Electrical indication of brake status
- Pneumatic valves for various functions
Technical data
- High variation of internal ratio from 2.0 to 5.5
- Block force of service brake up to 60 kN
- Block force of parking brake up to 45 kN
- Service unit can be added with spring or hand-applied parking brake
TreadAct Freight
Compact Freight Car Brake
The compact freight car brake as a member of the TreadAct Freight family makes the operation of freight cars increasingly economical and efficient. Due to its modular design, TreadAct Freight is reduced in weight, simple to install and reduces costs. It offers low maintenance and low air consumption while being highly efficient and delivering low life-cycle costs. This leads to an increased performance, which brings benefits for vehicle manufacturers and operators alike.
Customer benefits
- Optimum kinematics
- Modular design
- Low noise
- Low air consumption
- Can be equipped with bogie-mounted and car body-mounted manual parking brake
- Low weight
- Preassembled and ready to install
- High efficiency
- Low maintenance
- Overhaul period of 12 to 15 years (depending on environmental conditions)
Applications
- Freight cars in severe environmental conditions
- Freight cars with Y25 bogie
- Low-noise freight cars
- Lightweight freight cars
- Customization for other bogies possible
Key features
Push brake with two SINGLE-ACTING slack adjusters
- Entire block and wheel wear can be compensated
- Good accessibility for resetting
Modular design
- Block force is adjustable by changing the internal ratio without changing installation space or interface to the bogie
- Reduced installation time
Vibration-damped suspension
- Allows max. lateral movement and tilt of the axle with min. bearing clearance
- Less generation of noise
Version with integrated manual parking brake
- Overload protection by buffer spring
- Hand wheel position in the bogie or on the platform
- Hand wheel with integrated mechanical indication of parking brake status
Strongly protected against environmental impact
- Bearings are encapsulated and maintenance-free
- Overall low wear and very low maintenance requirement
Technical data
- Block force
- - of service brake 38 kN
- - of manual parking brake min. 28 kN
- Weight of service brake ~ 225 kg (BG version) / ~ 257 kg (BGU version)
- Adjusting capacity 205 mm
- Permissible lateral axle movement +/-20 mm
- Weight with manual parking brake ~ 282 kg (BGU version)
Steel-rubber-steel sleeves
- Less vibration
- Low noise
- Minimal wear
EddyAct
Linear Eddy Current Brake
Eddy current brakes create brake force independent of the adhesion between wheel and rail, similar to magnetic track brakes. Knorr Bremse's EddyAct offers enhanced safety levels and economic advantages. The system is completely independent of the track conditions and brake force remains constant, even at high speeds
Function principle
Eddy current brakes consist of a magnetic yoke with electrical coils that are positioned along the rail and magnetized with alternating north and south poles. Under current, the brake generates a symmetrical magnetic field. This leads to a brake force acting against the direction of travel and a vertical attractive force.
Customer benefits
- Independent of track conditions and the wheel-rail adhesion
- Wear-free, due to no mechanical contact
- No impact on TSI infrastructure
- Controllable brake force
- High brake force at high speed
- Additionally usable as service brake
- Noise-free, odorless and brake dust-free
Technical Data
- Standard dimensions: 130x269x1540 mm
- Weight: 900 kg per unit
- Brake force at 200km/h: 21 kN per unit
- Power requirement: max. 86 kW per unit
HydroAct
Hydraulic Brake Calipers
Knorr-Bremse's broad range of HydroAct hydraulic brake calipers is suitable for a wide variety of rail vehicles and requirements. Their robust design ensures they are protected against harsh environmental conditions. All HydroAct calipers feature automatic wear compensation and are maintenance-friendly – even when installed in very confined spaces.
Customer benefits
- High application force within a small installation space
- Application force adjustable and mechanical emergency release
- Mounting possible to gearbox as floating support or to the bogie frame as elastic fixation or axle mounted fixation
- Maintenance-friendly thanks to completely sealed bearings and joints, no greasing necessary
- Design principles successful worldwide and service proven for many years
- Optional remote mechanical release
Applications
- Light rail vehicles
- Metros
- Monorails
- People movers
HydroAct Lever (Type HC1P50) — Technical Data
- Floating caliper with lever-type design
- Spring actuator brake
- Brake force per brake disc up to 100 kN
- Two hydraulic release circuits
- Maximum width of brake disc 100 mm
- Weight without bracket approx. 60 kg
- Optionally available with elastic fixing
- Optionally available with remote mechanical release
HydroAct Lever (Type HC1P32) — Technical Data
- Floating caliper with lever-type design
- Spring actuator brake
- Brake force per brake disc up to 64 kN
- Two hydraulic release circuits
- Maximum width of brake disc 60 mm
- Weight without bracket approx. 35 kg
- Optionally available with elastic fixing
- Optionally available with remote mechanical release
HydroAct Unit (Type WZ80HZ45PS80) — Technical Data
- Brake caliper unit
- Spring actuator brake
- Brake force per brake disc up to 90 kN
- Two hydraulic release circuits
- Maximum width of brake disc 90 mm
- Weight approx. 115 kg
- Remote mechanical release
HydroAct Floating (Type HSC1P10N) — Technical Data
- Floating caliper frame-type design
- Spring actuator brake
- Brake force per brake disc 20 kN
- Two hydraulic release circuits
- Maximum width of brake disc 45 mm
- Weight approx. 15 kg
HydroAct Active (Type HSE1A30) — Technical Data
- Elastic-mounted caliper with frame-type design
- Active brake
- Brake force per brake disc 60 kN
- One hydraulic brake circuit
- Maximum width of brake disc 60 mm
- Weight approx. 37 kg
- Alternatively available as a spring actuator brake (see picture)
HydroAct Active (Type HF2A15) — Technical Data
- Fixed caliper
- Active brake
- Brake force per brake disc 60 kN
- One hydraulic brake circuit
- Maximum width of brake disc 60 mm
- Weight approx. 17 kg
EMB System — Digital-electromechanical Braking System
Digital-electromechanical Braking System
The Knorr-Bremse digital-electromechanical braking system (EMB system) is a paradigm shift in the fundamental principles of braking in rail vehicles. Unlike today's pneumatic or hydraulic braking systems the EMB system uses advanced brake-by-wire technology to transmit braking signals and generate brake force. Thereby it sets new standards of efficiency, reliability, and performance.
- Active system System control in all modes incl. backup without necessity of mechanical or hydraulic element
- Safety Meets all customer requirements of today's braking systems
- Complete system Provides brake control, brake energy and brake actuation
- Cybersecurity According to the state of the art
- Brake-by-wire Purely electrical generation and transfer of braking signal and energy
- Central enabler for airless train
- TSI-conformity Technical specifications of interoperability
FAQs
