Description
TS7Z28×60 Locking Assembly – 28mm Shaft 60mm OD Keyless Rigid Shaft-Hub Connector
The TS7Z28×60 serves 28 mm shaft applications including IEC frame 132 motors at higher power ratings. The 60 mm outer diameter provides sufficient ring wall section for reliable clamping at the 87 MPa surface pressure. This model is commonly used in conveyor drive heads, fan impeller hubs, and gearbox input shaft connections in the 3–7.5 kW motor power range. 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 — 87 MPa for the TS7Z28×60 at the specified M_a of 17 N·m — generates a friction connection that transmits both torque (Mt = 0.327 kN·m) and axial force (Ft = 25.2 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 | TS7Z28×60 |
| Type | Locking Assembly (Keyless Shaft-Hub Connection) |
| Shaft Bore (d) | 28 mm |
| Outer Diameter (D) | 60 mm |
| Rated Axial Force (Ft) | 25.2 kN |
| Rated Torque (Mt) | 0.327 kN·m |
| Surface Pressure (Ps) | 87 MPa |
| Installation Screw Torque (Ma) | 17 N·m |
| Mass (G) | 0.91 kg |
| Material | Steel |
| Standard | GB/T 5106 compatible |
Dimensional Reference
Structural Cross-Section
Installation and Design Guidance
Installation of the TS7Z28×60 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 (87 MPa) ≤ 0.9 × shaft yield strength. For C45 steel (yield ~370 MPa): 0.9 × 370 = 333 MPa > 87 MPa — acceptable. For aluminium alloy 6061-T6 (yield ~275 MPa): 0.9 × 275 = 247 MPa; compare with 87 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
★★★★★
Vietnam — Pulp & Paper Industry
Used in Yankee dryer drive connections in our tissue paper machine. The TS7Z28×60’s keyless connection eliminates the fretting fatigue issue we experienced with keyed connections under the high sustained torque and vibration loading of the Yankee drive.
— Project Manager, Ho Chi Minh City
★★★★★
United Arab Emirates — Thermal Power Station
Installed on steam turbine auxiliary drive shaft connections at our 3 MW coal-fired power station. The locking assembly’s zero-keyway design was selected based on our shaft fatigue analysis — eliminating the keyway stress concentration extended the calculated fatigue life from 80,000 to over 200,000 operating hours.
— Technical Manager, Dubai
★★★★☆
Egypt — Industrial Gearbox OEM
We use the TS7Z28×60 for output shaft connections on our range of industrial helical and bevel-helical gearboxes. The locking assembly is offered as a standard shaft termination option because it allows the gearbox to be mounted on a plain shaft without machining a keyway — simplifying customer installation.
— Senior Engineer, Cairo
Frequently Asked Questions
What is the Ft (axial force) capacity of the TS7Z?
Ft is the maximum axial force the locking assembly can resist at the specified installation torque. In most applications, the combined torque and axial force loading must be checked against the rated values — if both torque and axial force act simultaneously, the effective capacity of each is reduced proportionally. Consult the interaction formula provided in the product documentation.
What is the recommended minimum hub length for the TS7Z?
Hub length should be at least equal to the locking assembly’s body length, and the hub bore should have a H7 tolerance for standard fit. The hub material should have a yield strength sufficient to withstand the Ps radial contact pressure from the outer ring without plastic deformation.
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.
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.
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 TS7Z28×60 Locking Assembly
Ever Power manufactures the TS7Z28×60 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.