Keyless Locking Devices vs. Traditional Keyways – Why Choose a Z2 Tapered Locking Assembly
When connecting a shaft to a hub, engineers traditionally rely on keyways. However, keyless locking devices like the Z2 tapered assembly offer superior performance in demanding applications. This article compares both methods and explains why keyless technology is becoming the preferred choice.
What Is a Keyless Locking Device?
A keyless locking device (also called a shrink disc or locking assembly) uses mechanical interference to secure a shaft to a hub. The Z2 series features a double-tapered design that generates high radial clamping force with simple bolt tightening.
keyless locking device vs keyway
Z2 locking assembly benefits
tapered locking bushing
shaft locking device advantages
TLK200 series
keyless shaft connection
zero backlash coupling
Keyless vs. Keyway – Comparison
| Feature | Keyless Locking Device | Traditional Keyway |
|---|---|---|
| Backlash | Zero | Yes (key clearance) |
| Stress Concentration | Evenly distributed | High at keyway corners |
| Installation | Simple bolt tightening | Key fitting, machining required |
| Adjustability | 360° phase adjustment | Fixed position |
| Shaft Damage | None (no keyway) | Keyway weakens shaft |
| Torque Capacity | Very high | Limited by key shear strength |
. Advantages of the Z2 Double-Taper Design
Higher radial pressure – Double-taper generates more clamping force than single-taper designs
No axial movement – Tightening does not shift the assembly along the shaft
Easy disassembly – Pre-drilled threaded holes allow simple removal with standard tools
Multiple units – Can be used in series for extreme torque requirements
Common Applications
Keyless locking devices are widely used in:
Printing presses (register accuracy)
Packaging machinery (cyclic loads)
Machine tools (precision positioning)
Heavy industrial equipment (high torque)
Installation Tips
Clean all mating surfaces thoroughly
Lightly oil bolts and threads (do not oil tapered surfaces)
Tighten bolts progressively in a star pattern to the specified torque
Verify concentricity and runout after installation
Why Apexcoupling’s AL-S Z2 Series
Our Z2 locking assemblies are manufactured from high-strength 45# forged steel, heat-treated for dimensional stability and wear resistance. As a factory-direct supplier, we offer competitive pricing, full customization, and technical support.
For applications demanding zero backlash, high torque, and reliable shaft connections, keyless locking devices offer clear advantages over traditional keyways. The Z2 double-taper design delivers superior performance with simple installation and removal.
