SHAFT LOCKING DEVICES

Recently added . . . pages 76 to 82 In addition to the SIT-LOCK® keyless locking elements the . . . SER-SIT® taper lock bush designed to give the following: » perfect assembly. » rapid dismounting of the pulley and other transmission equipment. » no special tools requirement except hexagonal key. The large range of available finished bores ensures that an immediate assembly can be made thus avoiding costly factory downtime. Fastening by SER-SIT® bushes allows the removal of any clearance between hub and bore so that fretting corrosion is positively eliminated. SER-SIT® bushes are interchangeable...

Page SIT-LOCK® Keyless Locking Elements (advantages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Features - internal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Application examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SIT-LOCK 3 Internal locking device - self-centring . . . . . . . . . . . . . . . . . . . . . . . . ....

SIT-LOCK® Keyless Locking Elements Advantages compared to conventional systems Advantages of SIT-LOCK® on the shaft-hub connection compared with traditional systems Easy assembly and disassembly Both actions take place by locking and unlocking the clamping screws with common tools. The use of a torque wrench is only necessary when a more precise torque is required. Superior holding power The action of the clamping cones creates shaft clamping torque superior to a normal keyed hub. Overload protection When the pre-set torque is exceeded SIT-LOCK® will slip, preventing the connected elements from...

SIT-LOCK® Keyless Locking Elements Advantages compared to conventional systems A shaft to hub lock is critical in the design of a mechanical transmission as an unsuitable choice could cause serious damage to the machine or system and result in economic loss. Shaft-hub coupling designs must take several parameters into account: Assessing application loads: torque, bending moment, axial force, radial force. Stresses that may occur simultaneously; Alternating loads, sudden starts and stops, very rapid acceleration; Fatigue limits of the coupling components; Suitable material use; Frequent installation...

SIT-LOCK® Keyless Locking Elements Advantages compared to conventional systems Requires tight tolerances. Difficult to remove. Locking area temperature changes. The effect of the centrifugal force created by the hub can decrease transmissible torque. » Increased stress concentrated on the edges. Interference fit shaft-hub connections can be achieved by cooling the shaft or heating the hub. This type of connection is not widely used for the following reasons: Shaft strength depends on the type of coupling used As an example, we look at the following data. For a shaft with a diameter d equal to 50...

SIT-LOCK® Keyless Locking Elements Oxidation protection Even in damp environments, the pressures created along the contact surfaces do not allow for oxidation, ensuring easy removal of the locked parts. No backlash Connection in transmissions using SIT-LOCK® locking devices are perfectly rigid and there is no backlash that could impair motion transmission or machine precision over time. Recommended for applications subject to continuous alternating loads By using SIT-LOCK® locking devices, the stresses generated by alternating or sudden loads are distributed over the entire surface of the shaft...

SIT-LOCK® Keyless Locking Elements Applications with simultaneous torque and axial force SIT-LOCK® locking devices can simultaneously transmit torque Mt and tolerate an axial force Fax. The table shows the maximum permissible values. Where both values are present simultaneously, the transmissible torque Mt value decreases. Below is the formula for calculating transmissible torque: Mtam = Mtam = permissible torque (Nm) Mt = torque stated in table (Nm) FAXR = required axial force (N) d = shaft diameter (mm) Radial force influence The radial force FR affects the contact pressure on the shaft and hub...

SIT-LOCK® Keyless Locking Elements To simplify calculations, our Technical Department has drawn up a table for the coefficient K on the following page. Example calculation of minimum hub diameter Dmin Using the SIT-LOCK® 5B locking device to connect a shaft d = 50 mm with a hub made out of a material that has an elastic load σ0,2 = 500 N/mm², and a shape type and hub width equivalent to X=1. From the SIT-LOCK® 5B 50 x 80 table, the outer diameter D is equal to 80 mm, the pressure Pn on the hub is equal to 70 N/mm². In the table on the next page, by taking the Pn value (70 N/mm²), the X value (1)...

SIT-LOCK® Keyless Locking Elements Elastic load of hub material σ0,2 [N/mm²] Application type continued overleaf . . .

SIT-LOCK® Keyless Locking Elements Elastic load of hub material σ0,2 [N/mm²] Application type

SIT-LOCK® Keyless Locking Elements Features - internal SIT-LOCK® 3 » Self-centering. » Low surface pressures. » Suitable for using on hubs with a low σ0.2. » Available for shaft diameters of 6 to 130 mm. » No axial displacement when tightening the screws. » Compact dimensions. » Medium to high transmissible torques. SIT-LOCK® 4, SIT-LOCK® 4A » Self-centring. » Even pressure distribution. » Very high transmissible torques. » Available for shaft diameters of 25 to 400 mm. » No axial displacement when tightening the screws. » Removal via extraction threads. » Excellent perpendicularity. SIT-LOCK®...

SIT-LOCK® Keyless Locking Elements Features - internal SIT-LOCK® 6 » Self-centring. » Available for shaft diameters of 18 to 200 mm. » Axial displacement when tightening screws. » Optimal shaft-to-hub perpendicularity. » Reduced axial dimensions. » High transmissible torques. » Quick installation and removal. SIT-LOCK® 7 » Self-centring. » Quick installation and removal. » Available for shaft diameters of 18 to 200 mm. » No axial displacement when tightening the screws. » Excellent concentricity and perpendicularity. » Medium to high transmissible torques. SIT-LOCK® 8 » Self-centring. » Low surface...