High-Torque, Zero Backlash Brake

Sept. 7, 2016
For Indexing and Positioning Systems

Model I-300 spring engaged, air released, power-off brake is designed to provide high torque for backlash-free holding and emergency stopping on indexers and positioning systems. The I-300’s high torque and short response time ensure the shortest possible stopping distance.

The brake connects to the shaft with tapered, keyless locking devices. It is normally engaged until air pressure is applied to release it. Nexen’s patented braking element locks and holds the shaft in position without any displacement upon engagement or reversing of the load.

Key features for the I-300 brake include:

  • Zero Backlash for precise holding
  • High dynamic torque: 5300 in-lbs. (600 Nm)  
  • Torsionally stiff:  6,152,148 ft-lbs. per radian  (8,341,193 Nm/rad)
  • Spring engaged, air released: 60 psi (4.1 bar)
  • Engagement response time: 85 milliseconds
  • Stackable for double the braking torque
  • Horizontal or vertical mounting
  • Flange mounts to machine frame
  • Mounts to a bearing supported shaft



True Zero Backlash, High Torque, Spring Engaged Bake


IP67 Rated When End Mounted And Sealed To Machine Frame


Mounting Bushings Available From B-Loc, Lovejoy, Ringfeder, And Others. See Technical Data Sheet In Left Column.

Actuator Cycle Life:

1,000,000 Static Holding Cycles, E-Stops Or Dynamic Dynamic Stops Contact Nexen

Open Or Enclosed Design:


Bore Size:

65 mm

Bore Style:

Straight Keyless Bore With Customer Supplied Mechanical Compression Coupling

Over All Length:

105.0 mm

Over All Diameter:

280.0 mm

Minimum Static Brake Torque:

600 Nm

Brake Peak Thermal Input Rate:

17.00 hp

Shaft Inertia:

211.60 kgcm²

Max Rpm:




Port Size:

0.250 BSPT

Maximum Pressure:

6.9 bar

Minimum Release Pressure:

4.1 Bar

Temperature Range:

4.4 - 93°C

Coupling Brand/Type:

Mechanical Keyless Compression Bushing *Customer Supplied*

Torsional Rigidity:

8,341,193 Nm/rad


IP67 When Input Is Sealed To Machine Frame, CE, And RoHS


Black Acrylic Paint


Not Recommended For Cyclic Dynamic Braking


Other Bore Sizes Available Upon Request


66.0 LB