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.
Hydraulic actuation and the load path
The SHS family replaces the repeated bolt-tightening work of a mechanically actuated shrink disc with a hydraulic clamping process. Its construction retains the established principle of a three-part shrink disc, while separating the hydraulic system from the force-transmitting friction surfaces. That separation helps prevent hydraulic oil from contaminating the shaft-hub friction interface. The system is intended for applications requiring both a secure connection and efficient assembly or removal.
SHS family and test-stand designs
| Family / design | Primary purpose | Configuration note |
|---|---|---|
| SHS | Hydraulically clamped shaft-hub connection | Application-specific industrial design |
| SHS-P | Frequent clamping on transmission test stands | Quick handling with the specified locking arrangement |
| SHS-PA | Frequent clamping on transmission test stands | Application-specific test-stand configuration |
SHS-P and SHS-PA were developed for transmission test stands where repeated clamping and release form part of the operating cycle. The specified bayonet arrangement permits rapid locking and unlocking. Industrial SHS configurations instead address the required load, installation space and environment of the machine. These are application-specific solutions, so the family designation alone does not define a universal torque or bore size.
Technical configuration
| Characteristic | Specification / selection basis |
|---|---|
| Clamping principle | Hydraulic actuation; external frictional clamping |
| Nominal size and torque | Defined for the application and selected design |
| Catalog assembly-pressure example | 180–200 bar; confirm the requirement for the actual unit |
| Pressure after locking | Hydraulic pressure is released after the design-specific mechanical lock is secured |
| Inner ring | Can be adapted to different sizes |
| Maintenance and repair | Can be performed by the customer using the appropriate procedure |
Assembly and release sequence
Position the shrink disc on the hollow shaft and assemble the shaft-hub connection with the required surface preparation. Connect the hydraulic supply and establish the specified preload. The catalog describes an assembly-pressure example of 180–200 bar; this should be checked against the actual product documentation. Once preload is established, secure the tensioned position using the design-specific locking screws or bayonet ring, then release hydraulic pressure. The catalog permits hydraulic oil to be removed or retained for subsequent assembly, according to the procedure.
For removal, follow the reverse procedure for the selected construction. Separation of the pressure rings may be performed mechanically using screws or hydraulically using release pistons, depending on the design. The mechanical locking and release details are therefore essential ordering and maintenance information.
Friction surfaces and maintenance
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.
Applications and operating priorities
Typical uses include transmission test benches, wind turbines, cement production equipment, hydraulic motors, shredding machinery, conveying systems and mixing drives. Test-stand installations prioritize frequent, repeatable changes; industrial machinery may prioritize maintenance access and robust load transmission. Adaptable inner rings can help accommodate different size requirements, while protective measures can be specified for difficult environments. Maintenance and repair can be carried out by the customer in accordance with the relevant product procedure.
Selection and ordering information
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.
An enquiry should identify SHS, SHS-P or SHS-PA together with the machine duty, shaft and hub dimensions, desired changeover sequence, hydraulic connections, locking access and environmental protection requirements. Request the application drawing and confirm the pressure and release method for that exact configuration.