          
|
Please select a
product by using the drop-down menu below. What is a Torque Multiplier?
How Handtorque Torque Multipliers Work Handtorque multipliers incorporate an 'epicyclic' or 'planetary' gear train having one or more stages. Each stage of gearing increases the torque applied by a factor of 5, allowing Norbar to offer multipliers in ratios of 5:1, 25:1 and 125:1. In the planetary gear system, torque is applied to the input gear or 'sun' gear. Three or four planet gears whose teeth are engaged with the sun gear therefore rotate. The outside casing of the multiplier, or 'annulus' is also engaged with the planet gear teeth, and would normally rotate in the opposite direction to the sun gear. A reaction arm prevents the annulus from rotating, and this causes the planet gears to orbit around the sun. The planet gears are held in a 'planetary' carrier which also holds the output square drive. Therefore as the planet gears orbit around the sun. the carrier and so the square drive turns. Without the reaction arm to keep the annulus stationary, the output square will not apply torque. Why use a Handtorque Torque Multiplier? Safety - use of long levers can be dangerous. Torque multipliers mean a reduction in the lever length or operator effort by a factor of 5, 25 or 125. Space limitation - the use of a long lever may be impossible due to the available space. Accuracy - torque will be applied most accurately when it is applied smoothly and slowly. Torque multipliers enable this by removing much of the physical effort from the tightening task. Advantages of the Norbar Handtorque System Norbar gearboxes are built to an extremely high standard of precision All gears rotate on needle roller bearings about hardened and ground journal pins. As a result, Norbar Handtorques can be relied upon to have a torque multiplication accuracy of +4%, throughout the operating range, taking the uncertainty out of high torque tightening
Torque output calculations are therefore a matter of simple arithmetic with little risk of incorrect bolt loading due to conversion errors. Other manufacturer's multipliers often require graphs or formulae to calculate the input torque to achieve a particular output. The Norbar Handtorque is the most comprehensive multiplier range available. Standard products are available up to 47,500 N.m (35,000 Ibf.ft) and 'specials' to 100,000 N.m (73,000 Ibf.ft). A range of 'nose extensions' for reaching difficult to access bolts and a full range of torque transducers for highly accurate torque monitoring are available. Norbar Anti Wind Up Ratchet With
any high ratio gearbox (25:1 or more) a certain amount of wind up
(spring) has to be taken up before any useful tightening work is applied
to the nut. Each time the input device is released, the wind up will rotate it back against the direction of operation The Anti Wind Up Ratchet retains all of the wind up forces as they are created with the following benefits: 1.
The torque input device can not fly backwards against the
direction of operation if it is suddenly released. 2. Without an Anti Wind Up Ratchet, it will often be necessary to continue to make 360° sweeps with the torque input device otherwise the multiplier will 'unwind'. However, obstructions will often make this impossible. 3. With an Anti Wind Up Ratchet fitted, the multiplier becomes locked onto the nut because the reaction plate is held hard against the reaction point. This means that even used upside down, the multiplier will support it's own weight. Safety Note: Additional support is recommended as failure in the bolt, socket or multiplier will release the wind up forces and cause the multiplier to drop.
|
A
torque multiplier is a device that increases the torque that can be
applied by an operator. Because the power output can not exceed the
power input, the number of output revolutions will be lower than the
number of input revolutions (Torque x rpm = Power)
