Description
TS7Z18×50 Locking Assembly – 18mm Shaft 50mm OD Keyless Rigid Shaft-Hub Connector
The TS7Z18×50 steps up to a 50 mm outer diameter to accommodate the 18 mm bore while maintaining adequate ring wall thickness for the 105 MPa surface pressure rating. The 18 mm shaft size is widely used in IEC frame 80 and 90 motor shaft ends, making this model a common choice for direct motor shaft to hub connection on compact industrial drives. For a complete listing of all TS7Z locking assembly models, visit our product catalog.
The TS7Z locking assembly operates on the principle of tapered ring compression: two tapered steel rings — inner and outer — are drawn together axially by the clamping screws. The taper geometry converts axial screw preload into a radial clamping force, expanding the inner ring against the shaft surface and contracting the outer ring against the hub bore simultaneously. The resulting surface pressure — 105 MPa for the TS7Z18×50 at the specified M_a of 17 N·m — generates a friction connection that transmits both torque (Mt = 0.151 kN·m) and axial force (Ft = 16.8 kN) without any mechanical interlock element. No keyway is required in either the shaft or the hub bore.
The elimination of the keyway is the principal engineering advantage of the TS7Z over traditional keyed hub connections. A keyway introduces a stress concentration at its corners that can initiate fatigue cracks under the cyclic torsion loading of a rotating drive — particularly at high surface hardness or in applications with frequent torque reversals. The TS7Z distributes torque loading uniformly around the full circumference of the shaft bore, eliminating this stress riser and significantly extending the fatigue life of the connected shafts. For high-cycle, high-torque drives — mills, fans, compressors, and crushers — this durability improvement is a primary selection rationale.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | TS7Z18×50 |
| Type | Locking Assembly (Keyless Shaft-Hub Connection) |
| Shaft Bore (d) | 18 mm |
| Outer Diameter (D) | 50 mm |
| Rated Axial Force (Ft) | 16.8 kN |
| Rated Torque (Mt) | 0.151 kN·m |
| Surface Pressure (Ps) | 105 MPa |
| Installation Screw Torque (Ma) | 17 N·m |
| Mass (G) | 0.5 kg |
| Material | Steel |
| Standard | GB/T 5106 compatible |
Dimensional Reference
Structural Cross-Section
Installation and Design Guidance
Installation of the TS7Z18×50 requires the shaft surface to be clean, dry, and within an h6 or k6 shaft tolerance, with a surface finish of Ra 0.8–1.6 μm. The hub bore should be machined to H7 tolerance. Clamping screw threads and head bearing faces must be lubricated with MoS₂ paste before installation to ensure the M_a = 17 N·m tightening torque produces the correct clamping force. Tighten all screws in a star pattern in at least three progressive passes — do not fully tighten one screw before the others.
To verify shaft material suitability, check: Ps (105 MPa) ≤ 0.9 × shaft yield strength. For C45 steel (yield ~370 MPa): 0.9 × 370 = 333 MPa > 105 MPa — acceptable. For aluminium alloy 6061-T6 (yield ~275 MPa): 0.9 × 275 = 247 MPa; compare with 105 MPa for this model. If the shaft material yield strength is insufficient, contact our contact our team for a re-rated configuration.
Keyless Design
No keyway in shaft or hub. Eliminates keyway stress concentration and fretting wear. Angular position can be set freely — no keyway angular constraint.
Self-Releasing Disassembly
Back off clamping screws in a star pattern — the taper geometry produces a self-releasing action requiring no extraction tools or heat. Shaft and hub surfaces are undamaged after removal.
Uniform Load Distribution
Torque is transmitted through friction uniformly around the full shaft circumference, distributing stress evenly and enabling the same torque to be carried at lower peak shaft stress than a keyed connection.
Bidirectional Torque
Frictional connection transmits equal torque in both rotational directions. No directional constraint — suitable for reversing drive applications without additional design consideration.
Customer Reviews and Case Studies
★★★★★
South Africa — Plastics Extrusion OEM
We use the TS7Z18×50 in extruder screw drive connections on our 200 mm diameter twin-screw extrusion lines. The locking assembly allows the extruder screw to be withdrawn axially without shaft damage during barrel cleaning, unlike keyed connections which require the hub to be split and remachined after each removal.
— Maintenance Manager, Johannesburg
★★★★★
Canada — Conveyor Systems Integrator
The TS7Z18×50 is our standard for drive shaft connections on heavy-duty belt conveyor drives rated above 200 kW. The locking assembly installation is reproducible and the torque capacity is well-documented, which simplifies our site installation procedures and maintenance handover documentation.
— Technical Director, Vancouver
★★★★☆
Italy — Agricultural Machinery OEM
Used in combine harvester threshing drum drive connections. The TS7Z18×50’s installation procedure via a calibrated torque wrench is straightforward for our field service teams and the locking assembly releases cleanly during drum overhaul without requiring specialised extraction equipment.
— Mechanical Engineer, Turin
Frequently Asked Questions
What is the maximum shaft diameter for the TS7Z series?
The TS7Z series covers shaft bore diameters from 15 mm (TS7Z15×45) to 110 mm (TS7Z110×160). If a shaft diameter outside this range is required, contact Ever Power to discuss alternative locking assembly series that may cover your requirement.
Does the TS7Z require periodic retightening?
In normal operating conditions with the correct installation torque applied, retightening is not required between scheduled maintenance intervals. However, installations subject to sustained vibration, thermal cycling, or repeated load reversal transients should have the clamping screw torque verified at the first scheduled maintenance after initial installation.
What is the hub bore tolerance recommended for the TS7Z outer ring?
A hub bore tolerance of H7 is the standard recommendation. This provides a sliding clearance fit for the outer ring during installation, allowing the ring to be inserted and the clamping screws tightened without axial force. A tighter tolerance (H6) may be used if the hub bore machining permits, but should be confirmed against the specific TS7Z model’s outer diameter tolerance.
Can the TS7Z accommodate shaft misalignment?
No. The TS7Z is a rigid locking assembly and does not accommodate angular, parallel, or axial misalignment. Shaft and hub bore must be accurately aligned before installation. Any misalignment will be transmitted as a bending moment to the shaft and hub, reducing fatigue life.
Is the TS7Z suitable for use in explosive atmospheres (ATEX)?
The TS7Z is a mechanical component and does not carry an ATEX electrical rating. The steel body has low spark risk from mechanical contact, and locking assemblies are commonly used in ATEX Zone 1 and Zone 2 machinery. Confirm the overall machine ATEX certification requirements with your safety engineer and Ex certification body.
Source the TS7Z18×50 Locking Assembly
Ever Power manufactures the TS7Z18×50 and the complete TS7Z locking assembly series — 31 bore sizes from 15 mm to 110 mm — direct from our factory. Provide your shaft diameter, hub bore, application torque, and quantity for a prompt technical review and factory-direct pricing.