Servo Motor Brakes

How to Choose a Servo Motor Brake

Stearns provides servo motor brakes for holding-only applications. 

To determine the right type of servo motor brake, consider: 

• System safety requirements
• Power source 
• Space available
• The frequency in which the brake will need to start & stop 
• Longevity
• Maximum speed
• Maximum load weight 

Types of Servo Motor Brakes

Stearns offert two types of servo motor brakes for different application requirements:

• Holding servo motor brakes: mechanically-activated brakes that engage when the servo motor is not powered. Used to stop and hold the motor shaft, preventing external forces from moving the load when the motor is off. 
• Safety servo motor brakes: brakes that engage when power is off, stopping and holding the driven load. Used to prevent a load from falling when the servo motor is shut off.

Our power-off spring-set brakes are ideal for servo motor applications with system requirements that demand low inertia and high-speed operations.

External vs Integrated Servo Motor Brakes

Our AAB 310 and 311 Series are external servo motor brakes, which means they are mounted on the servo motor shaft externally rather than inside the motor housing. Our servo motor brakes can be mounted on either face: magnet body mount or pressure plate mount.

External servo motor brakes offer several advantages:

• Better for high-temperature environments: externally mounted brakes don't add heat inside the servo motor housing
• Simpler maintenance & replacement: no need to disassemble the motor system
• Performance optimization: you're not limited to the specifications of integrated servo motor brakes
• Maintain motor size constraints: an integrated brake can add to the size & weight of the motor unit
• Versatility: you can add an external servo motor brake to your system without replacing the motor, making it easier to upgrade or modify the system

How Servo Motor Brakes Work

Here’s how our spring-set electrically released servo motor brakes function: 

Spring-set servo motor brakes use friction to hold a rotating shaft driven by a servo motor. A hub attached to the shaft supports the rotating friction disc. Springs apply clamping force between the brake armature, friction disc and pressure plate.

When electrical power is on, electromagnetic force from the brake's magnet body assembly overcomes the spring action. The brake armature is pulled away, allowing the servo motor shaft to rotate.

Power-off servo motor brakes act as safety brakes. When electrical power is interrupted, the electromagnetic force in the magnet body is removed. The pressure spring forces the armature plate to clamp down on the friction disc, stopping the servo motor shaft from rotating.

Find a Custom Brake Size

• Use Brake Configurator
• Use Coil Converter

Use Cases for Servo Motor Brakes

Servo motor brakes are often used in vertical-axis applications in:

• Manufacturing production lines
• CNC machining
• Assembly stations
• Robotics
• Material handling
• Packaging equipment
• Medical equipment

These types of automated systems require the reliability, efficiency and precise control our servo motor brakes provide.

Benefits of Stearns Servo Motor Brakes

Servo motor brakes from Stearns deliver high torque in a compact package for servo and stepper motor applications.  Additional benefits include:

• Low backlash
• Class H insulation
• Corrosion resistant finishes
• Low inertia rotating parts
• Splined hub for quiet dependable operation

Features 

• Flexible torque sizing: Sizes ranging from 8 to 400 lb-in, (.9 to 45.2 Nm) of torque
• Dynamic mounting options: Including face mounting through a short hub for maximum efficiency
• Class H insulation: Designed with materials available in silicone elastomer, mica, glass fibre, asbestos & more

Find a Stearns Servo Motor Brake By Industry

• Food & Beverage
• Material Handling
• Packaging
• Healthcare & pharmaceutical manufacturing
• Robotics