SYBD Series Brake Harmonic Drive for Cobot Joints

"Brake and Harmonic Drive"?

A "brake and harmonic drive" is not a single product, but rather an integrated solution where a braking device is built into the harmonic drive or mounted on its input/output end.

There are two main forms of this integrated design:

1. Integrated Product : A highly compact module that integrates a harmonic drive with an electromagnetic brake or other components.

2. System Combination : A separate brake installed within a transmission system that already includes a harmonic drive, to achieve a specific function.Core Working Principle

Harmonic drives themselves achieve high reduction ratios and precision through the elastic deformation of a flex spline. The logic of adding a brake is clever, primarily in two ways:

1. Input-Side Braking : The brake is installed on the high-speed side (e.g., the motor). Due to the lever principle, only a small braking torque is required here. However, through the harmonic drive's reduction ratio (e.g., 160:1), this is amplified into a huge holding torque on the output side – a "four-ounce to a thousand-pound" effect.

2. Output-Side Braking : The brake acts directly on the low-speed side. This is mainly used to maintain joint posture in devices like robots when power is lost, preventing sagging due to gravity.

Key Application Areas

Thanks to its precision, compactness, and efficiency, this combination is widely used in high-end equipment:

• Robotics : Joint modules for industrial robots, collaborative robots (cobots), and humanoid robots – the most common application.

• Transportation : High-speed disc brake systems for bicycles, and electronic mechanical brake (EMB) systems for commercial vehicles.

• Specialized Equipment : Subsea tools (e.g., for 3,000-meter depths), and high-precision drive joints in aerospace equipment.

Integrated Brake-Harmonic Drive

Harmonic drive and electromagnetic brake integrated design
Easy to install and maintain, highly integrated, shortens axial dimension, suitable for compact spaces.

I. Structural Composition

The integrated brake-harmonic drive mainly consists of a harmonic drive and an electromagnetic brake.

The brake coil part is embedded into the harmonic drive housing, thereby reducing the overall length and weight.

The square hub of the brake is connected to the shaft of the wave generator.

• When the brake is de-energized (power off) , the brake locks the shaft of the wave generator, stopping its rotation.

• When the brake is energized (power on) , the brake is released, allowing the wave generator to rotate freely.