Valmet WIN3136875 Slide Clutch – Friction Coupling TLA150 (1‑inch x 25mm)

The Valmet WIN3136875 is a slide‑type friction clutch coupling, model TLA150, designed to provide overload protection and controlled slip in mechanical drive systems. Featuring a 1‑inch (25.4 mm) input shaft and a 25 mm output bore, this coupling is often found in marine and industrial applications, particularly in Wartsila propulsion ancillaries and auxiliary drives. The friction disc design ensures smooth engagement and disengagement, protecting equipment from torque spikes and jams.

Construction and Materials

The clutch body is manufactured from high‑grade ductile iron with a protective black oxide coating for corrosion resistance. The friction surfaces consist of sintered bronze pads bonded to a steel backing, offering stable friction coefficient over a wide temperature range. The sliding hub is splined to the input shaft and can move axially under spring loading to engage or disengage the drive. All fasteners are grade 12.9 to withstand high shear loads.

Torque and Slip Characteristics

The TLA150 clutch is rated for a nominal torque of 150 Nm with a slip torque range of 80‑200 Nm (adjustable via spring preload). The friction engagement is progressive, with a slip speed up to 150 RPM during overload conditions. Static torque capacity is 200 Nm, and the clutch can accommodate momentary peak torques up to 300 Nm without permanent deformation. The hysteresis is less than 5 %, ensuring consistent protection.

Shaft and Bore Specifications

Input side: 1‑inch shaft with a keyway (0.25 inch x 0.125 inch) and a threaded end for retaining hardware. Output side: 25 mm bore with two parallel keyways (8 mm wide) and a locking collar for secure attachment to the driven shaft. The overall length of the coupling is 120 mm, and the outer diameter is 85 mm. Both ends are machined to DIN 6885 tolerances for concentricity and balance.

Adjustment and Setting

The slip torque is set by adjusting the compression on a stack of Belleville washers located inside the hub. A graduated scale on the housing helps to set the desired torque value without disassembly. An optional torque indicator pin provides visual confirmation that the clutch is in the engaged position. Periodic re‑adjustment may be required after extended operation to compensate for friction surface wear.

Installation Guidelines

Before installation, ensure that the input and output shafts are clean and free of burrs. Apply a thin layer of anti‑seize compound to the shaft keyways. Align the clutch axially with the drive and driven units using a dial gauge to avoid eccentric loading. Tighten the locking collar and retaining bolts to the specified torque (40 Nm for the collar, 70 Nm for the input nut). Use a suitable coupling guard to enclose the rotating parts.

Maintenance and Inspection

Routine maintenance includes checking the friction pad thickness (minimum 3 mm) and inspecting the spring stack for cracks or loss of preload. Lubrication is not required as the clutch is pre‑greased for life; however, the sliding surfaces should be wiped clean and lightly oiled at each service interval. A simple clutch slip test can be performed by applying a known torque and measuring the slip RPM; adjust if deviating from setpoint.

Environmental Compatibility

The WIN3136875 operates reliably in ambient temperatures from ‑30 °C to +100 °C. It is resistant to mineral oils, hydraulic fluids, and mild acids. The clutch is IP54 rated for dust and moisture protection. It is suitable for outdoor and marine environments with proper corrosion protection.

Applications

This coupling is commonly used in deck machinery, winch drives, conveyor systems, and pump drives where occasional overload protection is required. In marine propulsion, it protects the main engine from shock loads caused by sudden propeller fouling. In industrial mills, it safeguards roll drives from jamming due to product buildup.

Safety and Certifications

The clutch complies with ISO 13849‑1 for emergency stop functions and has been tested for fatigue strength per DIN 740‑2. It is recommended to use a torque limiting device in conjunction with an emergency stop circuit for full operator safety.

Conclusion

The Valmet WIN3136875 slide clutch friction coupling TLA150 provides dependable overload protection and torsional flexibility in a compact package. Its robust construction and adjustable torque settings make it a versatile choice for mechanical power transmission in challenging environments.