Description
TS7Z70×115 Locking Assembly – 70mm Shaft 115mm OD Keyless Rigid Shaft-Hub Connector
At 70 mm bore and 115 mm OD, the TS7Z70×115 marks entry into the large-frame section of the TS7Z range. The M_a installation torque increases to 84 N·m — confirming the larger fastener size at this frame. Rated torque of 2.02 kN·m covers large industrial gearbox connections, mill drives, and heavy-duty conveyor systems in the 500 kW to 1 MW 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 — 49 MPa for the TS7Z70×115 at the specified M_a of 84 N·m — generates a friction connection that transmits both torque (Mt = 2.02 kN·m) and axial force (Ft = 62.4 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 | TS7Z70×115 |
| Type | Locking Assembly (Keyless Shaft-Hub Connection) |
| Shaft Bore (d) | 70 mm |
| Outer Diameter (D) | 115 mm |
| Rated Axial Force (Ft) | 62.4 kN |
| Rated Torque (Mt) | 2.02 kN·m |
| Surface Pressure (Ps) | 49 MPa |
| Installation Screw Torque (Ma) | 84 N·m |
| Mass (G) | 4.1 kg |
| Material | Steel |
| Standard | GB/T 5106 compatible |
Dimensional Reference
Structural Cross-Section
Installation and Design Guidance
Installation of the TS7Z70×115 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 = 84 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 (49 MPa) ≤ 0.9 × shaft yield strength. For C45 steel (yield ~370 MPa): 0.9 × 370 = 333 MPa > 49 MPa — acceptable. For aluminium alloy 6061-T6 (yield ~275 MPa): 0.9 × 275 = 247 MPa; compare with 49 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
★★★★★
United Kingdom — Paper Mill Equipment
We use the TS7Z70×115 in our paper machine dryer section drive connections. The locking assembly provided a repeatable, calibrated installation that eliminated the variability we saw with previous keyway connections. The 2.02 kN·m torque capacity provides a comfortable safety margin over our peak drive torque.
— Technical Buyer, Birmingham
★★★★★
Poland — Shipbuilding & Marine
We use the TS7Z70×115 for propeller shaft to reduction gearbox connections on our patrol vessels. The taper-free locking assembly design simplifies shaft removal during dry-dock maintenance compared to previous tapered hub arrangements. The 84 N·m installation torque is easily achieved with standard marine tools.
— Design Engineer, Warsaw
★★★★☆
Italy — Agricultural Machinery OEM
Used in combine harvester threshing drum drive connections. The TS7Z70×115’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
How does the TS7Z locking assembly compare to a keyed connection?
A locking assembly distributes torque and axial force uniformly around the shaft circumference through friction, eliminating the stress concentration of a keyway. This typically allows the same torque to be transmitted through a smaller shaft diameter, or significantly extends fatigue life at the same shaft size. Locking assemblies also allow precise angular positioning, which is not possible with a keyed connection unless the keyway is machined to a specific angular reference.
Can the TS7Z be installed and removed without special tools?
Installation requires only a calibrated torque wrench with the correct hex key bit for the clamping screws. Removal is performed by loosening the clamping screws in a star pattern — the tapered ring geometry produces a self-releasing action as the screws are backed off. No hydraulic or heating tools are required for standard installations.
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.
Can the TS7Z be used with hollow shafts?
Yes, provided the hollow shaft wall thickness is sufficient to withstand the Ps radial contact pressure without collapse. For hollow shaft applications, calculate the wall stress using the thick-walled cylinder formula with the inner pressure equal to Ps and the relevant wall geometry. Contact Ever Power if you require assistance with the hollow shaft calculation.
What surface treatment is applied to the TS7Z?
The standard TS7Z locking assembly components are manufactured from steel with a phosphate or similar surface treatment that provides moderate corrosion protection during storage and in dry industrial environments. For outdoor or wet environments, additional protection such as periodic light oiling of external surfaces is recommended.
Source the TS7Z70×115 Locking Assembly
Ever Power manufactures the TS7Z70×115 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.