Boat reduction gearbox BRG10-50

rudder

The BRG10-50 bevel reduction gearbox transforms a rotational movement into a push-pull movement. The reduction gearbox is always positioned close to the rudder stock. Via a draglink with rose joints, the push-pull movement is transmitted to the tiller lever and rudder shaft. The BRG10-50 has a gear reduction of 5:1. This results in 1.8 revolutions of the input shaft for a corresponding 72 degrees of rudder travel. This can be increased with steps of 1.2:1 by using step ratio bevel boxes (2.2 turns with one step ratio and 2.7 turns with two step ratio bevel boxes). The output lever centres are 130 mm to a corresponding 200 mm centres of the tiller lever. This difference in length results in the so called "wide angle geometry". Please click here for more in depth explanation. The maximum input torque is 40.5 KgfM resulting in a maximum rudder torque of 591 KgfM. The maximum rudder torque according to the CE rating is 208 KgfM midships and 394 KgfM full rudder (the CE regulations use a safety factor of 150%). This makes the gearbox suitable for boats from 30 to around 48. Except for the input shaft and the gears, the complete gearbox is machined out of solid aluminium 6082 for maximum strength and minimum weight. Positioning the reduction gearbox correctly to the rudderstock is very important for the wide angle geometry to function correctly.