Spring applied power off brake
Fail-safe, spring applied power off brakes for use in demanding applications. Designed with power-off brake engagement, engaging when electrical power supply is removed.
Enquire NowKey features
- Fail-safe (Spring Applied)
- Power off brake engagement/electrically released
- High braking torque
- High operating speeds (dependent on size)
- Precision holding
- Low moment of inertia
- Horizontal and vertical mounting
- Splined hub/friction disc connection
- Water resistant versions available
- Optional voltages
Product description
The electromagnetic spring applied power off brake (sometimes known as a safety brake or fail-safe brake) is designed so that when the electrical power supply is removed, the brake engages (power-off brake engagement). The spring applied brake can be designed to be used as a holding brake (parking), or dynamically when an emergency stop function is required (E-stop).
Our spring applied power off brakes are robust and reliable, generally incorporating multiple internal compression springs. The multiple springs provide an added safety feature, ensuring that the brake would still function should one spring fail prematurely. When power is cut the coil’s magnetic field decays, the springs force an axially moving armature plate forwards to engage and lock the rotating friction disc. The electromagnetic spring applied brake is ideal for integration into servomotors and can be mounted externally or integrated into the motor housing.
Friction options
The electromagnetic spring applied brake is one of our most versatile brakes with a torque range of 0.05Nm to 300Nm. The non-asbestos lining construction of the rotating friction element is available in three different types (depending upon the application and torque required):
1. Mainly static applications – single piece friction disc assembly, with drive interface direct into friction discs
2. Mainly semi-dynamic applications – aluminum carriers with double bonded friction discs for increased shear strength and shock loading
3. Higher strength applications – steel carriers of hardened steel with double bonded friction discs, for more demanding and dynamic applicationsDepending on the acceptable level of backlash, some spring applied power off brakes have the option to have either a spline or hexagonal drive ensuring minimal circumferential backlash.
Air gap
During its manufacture, the air gap is pre-set on the spring applied brake for ease of installation. Where longer term `in-situ` air gap resetting is required, this can be achieved with adjustable spacers, without needing to totally remove the brake from the motor.
Override release
The spring applied brake has a hand release option to manually override the brake without power. This is suited to applications such as fork lift truck machinery, wheelchairs and actuation and valve systems.
Mounting options
The spring applied power off brake can be face mounted or flange mounted in any orientation and due to its reliability, is suited to safety critical applications in the material handling, military and medical sectors. They are often used in automation and robotic applications as well as packaging machines, storage systems and in renewable energy.
Temperature tolerance
As the spring applied brake does not contain permanent magnetic material, it is more tolerant of high temperatures than the permanent magnet brake. Its temperature range is between – 15°C to 120°C. An ‘IP’ water (or “Ingress Protection”) resistant design may also be available for installation into moist environments.
Rubber dust sealing rings may be incorporated to prevent ingress of foreign matter. Drive hubs can be supplied with brakes, complete with bore and keyways to suit the specific application.
Key features
- Fail-safe (Spring Applied)
- Power off brake engagement/electrically released
- High braking torque
- High operating speeds (dependent on size)
- Precision holding
- Low moment of inertia
- Horizontal and vertical mounting
- Splined hub/friction disc connection
- Water resistant versions available
- Optional voltages
Product description
The electromagnetic spring applied power off brake (sometimes known as a safety brake or fail-safe brake) is designed so that when the electrical power supply is removed, the brake engages (power-off brake engagement). The spring applied brake can be designed to be used as a holding brake (parking), or dynamically when an emergency stop function is required (E-stop).
Our spring applied power off brakes are robust and reliable, generally incorporating multiple internal compression springs. The multiple springs provide an added safety feature, ensuring that the brake would still function should one spring fail prematurely. When power is cut the coil’s magnetic field decays, the springs force an axially moving armature plate forwards to engage and lock the rotating friction disc. The electromagnetic spring applied brake is ideal for integration into servomotors and can be mounted externally or integrated into the motor housing.
Friction options
The electromagnetic spring applied brake is one of our most versatile brakes with a torque range of 0.05Nm to 300Nm. The non-asbestos lining construction of the rotating friction element is available in three different types (depending upon the application and torque required):
1. Mainly static applications – single piece friction disc assembly, with drive interface direct into friction discs
2. Mainly semi-dynamic applications – aluminum carriers with double bonded friction discs for increased shear strength and shock loading
3. Higher strength applications – steel carriers of hardened steel with double bonded friction discs, for more demanding and dynamic applicationsDepending on the acceptable level of backlash, some spring applied power off brakes have the option to have either a spline or hexagonal drive ensuring minimal circumferential backlash.
Air gap
During its manufacture, the air gap is pre-set on the spring applied brake for ease of installation. Where longer term `in-situ` air gap resetting is required, this can be achieved with adjustable spacers, without needing to totally remove the brake from the motor.
Override release
The spring applied brake has a hand release option to manually override the brake without power. This is suited to applications such as fork lift truck machinery, wheelchairs and actuation and valve systems.
Mounting options
The spring applied power off brake can be face mounted or flange mounted in any orientation and due to its reliability, is suited to safety critical applications in the material handling, military and medical sectors. They are often used in automation and robotic applications as well as packaging machines, storage systems and in renewable energy.
Temperature tolerance
As the spring applied brake does not contain permanent magnetic material, it is more tolerant of high temperatures than the permanent magnet brake. Its temperature range is between – 15°C to 120°C. An ‘IP’ water (or “Ingress Protection”) resistant design may also be available for installation into moist environments.
Rubber dust sealing rings may be incorporated to prevent ingress of foreign matter. Drive hubs can be supplied with brakes, complete with bore and keyways to suit the specific application.
To download the technical drawings for this product fill in your details below and we will send you a link to the files.
"*" indicates required fields
Spring applied power off brake technical drawing
See related downloads for full datasheet
Download drawingsSee related downloads for full datasheet
| Unit ref | Static Torque (Nm) | A - Diameter (mm) | L - Length (mm) | Maximum Bore | Power (Watts) | Voltage (V) |
|---|---|---|---|---|---|---|
| SA-35 | 0.15 | 35 | 27.0 | 6.0 | 5.0 | 12 or 24 |
| SA-40 | 0.4 | 40 | 30.5 | 8.0 | 5.3 | 12 or 24 |
| SA-42 | 0.4 | 42 | 32.0 | 8.0 | 5.0 | 12 or 24 |
| SA-55 | 2.5 | 55 | 32.0 | 8.0 | 12.0 | 12 or 24 |
| SA-60 | 4.0 | 60 | 32.0 | 8.0 | 12.0 | 12 or 24 |
| SA-70 | 7.0 | 70 | 34.1 | 15.0 | 15.0 | 12 or 24 |
| SA70-1 | 10.0 | 70 | 46.5 | 15.0 | 17.3 | 12 or 24 |
| SA-77 | 6.0 | 77 | 39.9 | 20/25* | 16.0 | 12 or 24 |
| SA77-1 | 12.0 | 77 | 39.9 | 20/25* | 20.0 | 12 or 24 |
| SA-90 | 20.0 | 90 | 43.9 | 20/25* | 20.0 | 12 or 24 |
Related products
Permanent magnet power off brake
Learn MorePermanent magnet power off brake
Fail-safe, zero backlash permanent magnet power off brakes for use in high precision, high power applications.
Flange mounted power on brake
Learn MoreFlange mounted power on brake
Backlash free, electromagnetic flange mounted power on brake for energised stopping in static and dynamic applications.
Electro-permanent holding magnet
Learn MoreElectro-permanent holding magnet
Power to release electro-permanent magnets providing an energy efficient and reliable solution.
Electromagnetic holding magnet
Learn MoreElectromagnetic holding magnet
High holding force in a compact design, our electromagnets are available in a range of fixings, sizes and forces.
Clutch brake hexagonal housing
Learn MoreClutch brake hexagonal housing
Pre-assembled combined clutch brake units with hexagonal housing.
Clutch brake extruded housing
Learn MoreClutch brake extruded housing
Pre-assembled combined clutch brake units with extruded housing.