Description
TS7Z48×90 Locking Assembly – 48mm Shaft 90mm OD Keyless Rigid Shaft-Hub Connector
At 48 mm bore and 90 mm outer diameter, the TS7Z48×90 addresses large IEC motor shaft ends and custom gearbox connections in the heavy industrial drive segment. The 1.053 kN·m rated torque and 69 MPa surface pressure provide a robust, traceable shaft connection for sustained high-torque duty in cement, mining, and paper industry 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 — 69 MPa for the TS7Z48×90 at the specified M_a of 42 N·m — generates a friction connection that transmits both torque (Mt = 1.053 kN·m) and axial force (Ft = 46.8 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 | TS7Z48×90 |
| Type | Locking Assembly (Keyless Shaft-Hub Connection) |
| Shaft Bore (d) | 48 mm |
| Outer Diameter (D) | 90 mm |
| Rated Axial Force (Ft) | 46.8 kN |
| Rated Torque (Mt) | 1.053 kN·m |
| Surface Pressure (Ps) | 69 MPa |
| Installation Screw Torque (Ma) | 42 N·m |
| Mass (G) | 2.3 kg |
| Material | Steel |
| Standard | GB/T 5106 compatible |
Dimensional Reference
Structural Cross-Section
Installation and Design Guidance
Installation of the TS7Z48×90 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 = 42 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 (69 MPa) ≤ 0.9 × shaft yield strength. For C45 steel (yield ~370 MPa): 0.9 × 370 = 333 MPa > 69 MPa — acceptable. For aluminium alloy 6061-T6 (yield ~275 MPa): 0.9 × 275 = 247 MPa; compare with 69 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
★★★★★
Portugal — Railway Maintenance Equipment
Installed on wheel set drive connections on our track geometry measurement vehicles. The TS7Z48×90 provides a precisely reproducible connection that can be disassembled and reassembled to the same torque standard at each wheelset overhaul. The published preload torque of 42 N·m is the key parameter for our maintenance procedure.
— Design Engineer, Porto
★★★★★
Argentina — Pump & Compressor OEM
Installed on compressor crankshaft to flywheel connections on our reciprocating gas compressors. The locking assembly’s keyless connection distributes torque through friction over the full bore surface rather than concentrating load at a key, which our fatigue analysis showed extended shaft service life by an estimated 40% under our operating cycle.
— Engineering Manager, Buenos Aires
★★★★☆
Indonesia — Metallurgical Equipment
Installed on billet rolling mill drive connections. The TS7Z48×90 handles the peak torque during cobble-clearing operations — a significant shock load above normal rolling torque — without slip. The locking assembly’s frictional connection distributes this shock load evenly rather than transmitting it through a key contact point.
— Applications Specialist, Jakarta
Frequently Asked Questions
How does shaft diameter affect the rated torque of a locking assembly?
Rated torque Mt scales approximately with the cube of shaft diameter for a given surface pressure. This is why the TS7Z series shows a large increase in Mt from smaller models (0.126 kN·m for TS7Z15×45) to larger ones (7.20 kN·m for TS7Z110×160) — the shaft diameter increase drives a disproportionate increase in torque capacity at a similar or lower surface pressure.
Is the TS7Z suitable for very low-speed, high-torque applications?
Yes. Locking assemblies are particularly well suited to low-speed, high-torque applications such as crusher drives, mill drives, and mixer agitators — where the torque per unit of shaft diameter is high and keyway fatigue is a concern. The TS7Z’s frictional connection distributes load uniformly without the stress concentration of a keyway.
How do I calculate whether the TS7Z is suitable for my application?
Three checks are required: (1) Mt ≥ application torque × safety factor; (2) Ft ≥ application axial force × safety factor; (3) Ps ≤ 0.9 × shaft material yield strength. A recommended safety factor of 1.5 to 2.0 should be applied to rated values. Contact Ever Power’s engineering team for a free application check if you have any uncertainty.
How is the installation torque Ma applied to the TS7Z?
The M_a value is the tightening torque applied to each of the locking assembly’s clamping screws during installation. Tighten the screws progressively in a star pattern — not sequentially around the circumference — until all screws reach the specified M_a torque. This ensures even distribution of clamping force and symmetric shaft contact pressure.
What happens if the TS7Z is over-tightened beyond M_a?
Over-tightening beyond the specified M_a torque can over-stress the tapered rings, cause plastic deformation of the shaft surface, and make disassembly difficult. Always use a calibrated torque wrench or torque driver for installation. If screws cannot reach M_a due to ring contact, check that the correct bore size has been specified.
Source the TS7Z48×90 Locking Assembly
Ever Power manufactures the TS7Z48×90 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.