Friction fastener
Friction clamping devices are fastening elements that secure a shaft and a hub (such as pulleys, sprockets, and couplings) using frictional force instead of keys. When the tapered inner and outer rings are drawn together axially by tightening bolts, the wedge action presses the inner ring against the shaft and the outer ring against the hub bore in the radial direction. The contact pressure generated by this force transmits torque and axial thrust through friction. No keyway machining is required, the mounting position and angular phase can be adjusted freely, and a play-free connection is achieved. In addition to standard types, there are configurations for applications requiring a reduced hub outer diameter, as well as specifications with rust-preventive treatment such as electroless Ni plating. Some products feature jacking screw holes for easier disassembly.
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Friction fastener
POSI LOCK PSL-D Standard Type
A clamping element that secures a shaft and hub by friction force. Tightening the clamping bolts fixes the hub to the shaft, and it can be used without keyways. Allowable torque and thrust force by size are listed for PSL-D-6 through PSL-D-50.
Miki Pulley
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Friction fastener
POSI LOCK PSL-D(C) Type Simple Anti-Corrosion Specification
PSL-D standard type with simple anti-corrosion treatment by electroless Ni plating. From PSL-D-16-C to PSL-D-50-C.
Miki Pulley
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Friction fastener
POSI LOCK PSL-G
Locking-fit fastening element for large-diameter hubs with reduced hub outer diameter. Includes design criteria for PSL-G sizes 19 to 120 and a list of minimum hub outer diameters.
Miki Pulley
How to choose Friction fastener
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1. Select the Applicable Shaft Diameter
Friction clamping devices are sized for each shaft diameter, and the listed products cover a range of 19 to 120 mm. Shaft tolerance and surface roughness affect frictional force, so confirm that the shaft meets the tolerance specified by the manufacturer. When using a hollow shaft, check whether it will deform under contact pressure.
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2. Allow Margin in Allowable Torque
The maximum transmittable torque for the listed products is 6 to 1760 N·m. Consider starting shocks and fluctuating loads, and select a size whose allowable torque is at or above the actual torque multiplied by a service factor appropriate to the nature of the load.
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3. Verify Combined Thrust Load
Axial force is also transmitted by friction, so check the allowable thrust force (listed range 2100 to 70300 N). When torque and thrust act simultaneously, evaluation is generally based on their combined effect, so verify against the manufacturer's calculation formula.
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4. Check Hub Outer Diameter and Strength Against Contact Pressure
The outer diameter of the clamping device corresponds to the hub bore diameter. Because contact pressure from the outer ring acts on the hub, determine the minimum hub outer diameter from the hub contact pressure and the yield point of the hub material. If a smaller outer diameter is required, refer to the types that include a minimum hub outer diameter selection table.
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5. Confirm Overall Length Relative to Hub Width
Confirm that the axial overall length of the clamping device fits within the hub width, and that there is sufficient space for bolt heads and tools. If the hub width is insufficient, the contact area is reduced and the specified transmission capacity cannot be achieved.
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6. Tightening Torque Control and Operating Environment
The clamping bolts must be tightened evenly to the specified torque (listed range 1 to 34 N·m); insufficient tightening causes slippage. The listed products have an operating temperature range of -40 to 150 °C. In humid environments, select specifications with rust-preventive treatment such as electroless Ni plating.
This guide was written by AI based on the listed products' documents and specification items. Check each manufacturer's documents before adopting.