Z11 Type Locking Assembly(JB/T 7934‑1999)
Z11 type shrink disc is an external‑clamping keyless locking assembly in accordance with JB/T 7934‑1999 standard. It adopts external locking structure. The whole shrink disc is fitted on the outer circle of the hub without direct contact with the drive shaft. Multiple sets of 12.9‑grade high‑strength bolts on the outer ring tighten the conical rings. The conical rings shrink inward to compress the hub, so that the hub clamps the shaft tightly to transmit heavy torque and combined axial loads.
Main Features
1. External‑clamping structure, especially suitable for thin‑wall hubs, preventing hub cracking during installation.
2. High torque‑carrying capacity. It can be used as a single unit, or multiple units can be connected in series for further higher load capacity.
3. Fully equipped with 12.9‑grade high‑strength hexagon socket screws. Screws shall be tightened diagonally in several steps strictly following standard torque values during installation.
4. Keyless connection eliminates shaft strength reduction caused by keyways. Arbitrary angular adjustment is available. Non‑destructive assembly and disassembly for repeated usage.
5. Capable of withstanding shock loads and frequent forward‑reverse rotation. Overload slipping protects drive components.
6. Excellent centering performance with low radial run‑out in operation.
Structural note: Z1‑Z5 are installed between shaft and hub; Z7 and Z11 are fitted on the outer diameter of the hub. Please distinguish the structure for correct selection.
Recommended Machining Tolerances
‑ Shaft: h7 / h8
‑ Hub bore: H7 / H8
‑ Mating surface roughness: Rz ≤ 16 μm
Applications
Large‑size drums, metallurgical equipment, heavy‑duty mining transmission, output ends of heavy gearboxes, large rollers, fans, papermaking equipment, heavy mixers.