TAS Schäfer shrink discs create an external frictional connection between a shaft and a hollow shaft or hub. Axial actuation of conical components generates radial pressure, compressing the hub onto the shaft. The resulting shaft-hub interface transmits the load without backlash. The shrink disc supplies the clamping force; it does not itself carry the torque through the shaft-to-hub power path.
Three-part construction and force generation
The three-part construction uses two pressure rings and a slotted inner ring. One pressure ring contains the threaded holes and the other has through holes for the clamping screws. Tightening the screws draws the conical components together, reducing the effective inner diameter and building radial contact pressure. The catalog describes the TAS 30.. range as non-self-locking, with the clamping force controlled through the screws.
Series and design coverage
| Series / design | Product-family designation |
|---|---|
| 3073 | Mini-Range |
| 3051 | Light-Range |
| 3051 Split | Split Light-Range |
| 3071 | Standard-Range |
| 3071 Split | Split Standard-Range |
| 3081 | Strengthened Standard-Range |
| 3091 | Heavy-Range |
| 3091 Split | Split Heavy-Range |
| 3093 | Strengthened Heavy-Range |
| Type 52 | Additional three-part type family |
Published product-group range
| Parameter | Published product-group range / characteristic |
|---|---|
| Transmittable torque | 27–12,541,000 Nm |
| Nominal diameter d | 14–1,000 mm |
| Construction | Three-part external clamping device |
| Main components | Threaded pressure ring, through-hole pressure ring and slotted inner ring |
| Clamping control | Clamping-screw force / specified tightening condition |
| Self-locking behavior | TAS 30.. range is not self-locking |
| Fit accommodation | Compensation for increased fitting clearance |
| Options | Different designs and special surface finishes |
The published diameter and torque intervals describe the complete product group, including different ranges and sizes. They are not the individual rating of each series. Keep the nominal shrink-disc diameter d separate from shaft diameter d_w. For any selected unit, confirm its detailed geometry, tightening values, allowed speed and shaft-hub material requirements.
Assembly and disassembly
Three-part shrink discs use a larger cone angle than the two-part construction described in the product comparison. This allows the connection to release when the clamping screws are loosened, without the push-off screw arrangement used for the compared two-part designs. Follow the installation and release sequence for the selected size and type. Maintain the required clamping length and mounting position, and ensure that the components have the specified surface condition before actuation.
Contact surfaces and lubrication
The shaft-to-hub contact surfaces must be clean, dry and free of grease. This requirement differs from the preparation of the shrink-disc functional surfaces and the interface between the hub and the shrink-disc bush or inner ring, which require the specified lubrication. Keep those surface requirements separate during preparation. The catalog identifies lubrication at screw threads and under screw heads; use the lubricant and procedure specified for the selected design.
TAS 3073 Mini-Range details
| TAS 3073 Mini-Range characteristic | Catalog detail |
|---|---|
| Finish | Discs galvanized |
| Washers | Without washers |
| Dimensions H and e | Stated in the unlocked position |
| Minimum yield strength Rp0.2 — solid shaft | 290 N/mm² |
| Minimum yield strength Rp0.2 — hub | 350 N/mm² |
| Ordering pattern | TAS 3073-d; further sizes on request |
The listed TAS 3073 Mini-Range uses galvanized discs without washers. Its H and e dimensions are stated for the unlocked condition. The minimum shaft and hub yield strengths shown above belong to that catalog configuration and should be verified against the actual material properties. Other ranges and strengthened constructions require their own dimensional and load checks.
Range and split-design illustrations
Choosing standard, strengthened and split designs
The catalog separates light, standard, heavy and strengthened ranges, and also lists split versions of the 3051, 3071 and 3091 designs. Preserve that distinction in the specification and replacement enquiry. A split design is a defined construction choice rather than a general instruction to divide a standard ring. Check its assembly arrangement, available space and exact catalog designation before specifying it for the machine.
Reading the technical data
| Symbol | Meaning | Unit |
|---|---|---|
| d | Nominal diameter of the shrink disc | mm |
| d_w | Shaft diameter | mm |
| D | Outer diameter | mm |
| H | Shrink-disc width | mm |
| M_max | Maximum transmittable torque | Nm |
| M_A | Clamping-screw tightening torque | Nm |
| p_N | Average pressure applied to the hub | N/mm² |
| n_max | Permitted rotational frequency | min⁻¹ |
Maximum transmittable torque M_max describes the assembled connection, while M_A denotes the clamping-screw tightening torque. Neither should be substituted for the other. The average pressure applied to the hub and the permitted rotational frequency also depend on the selected size. Changes to shaft diameter, clamping length or material strength require the connection to be reassessed rather than relying on a family-wide maximum.
Applications
Three-part shrink discs are used in wind-power drives, industrial drive systems, raw-material extraction, conveying, crushing, mixing and process equipment, and on hollow-shaft gearboxes. The product information also identifies their use with TAS WK shaft couplings and TAS FK and FKB flange couplings. The full coupling assembly must be selected for its duty; a shrink-disc series designation alone does not define the complete coupling rating.
Selection and ordering
Selection requires more than a nominal diameter and a torque value. Record the shaft diameter, hub outside diameter, clamping length, available axial and radial space, shaft and hub material properties, operating speed, load history and environmental conditions. Include simultaneous axial force, radial loading or bending where present so the complete connection can be assessed. Verify the selected size against its data sheet and installation instructions before specifying screw tightening or releasing the assembly.
Identify the series, nominal diameter, shaft diameter and required standard, strengthened or split version. The Mini-Range ordering format is TAS 3073-d. For Type 52 or a special surface finish, obtain the exact type-specific dimensional information before finalizing the specification.