The Jefa RG10-70 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 RG10 gearbox
is very versatile as it can be equipped with one (standard), two or three input
shafts. On top of that one can choose the output shaft at the opposite
side of the input shafts (type 1) or at the same side (type 2). The gear
ratio IS 1:7 (2.5 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 (3.1 turns
with one step ratio and 3.8 turns with two step ratio bevel boxes). The output
lever centres are 165 mm to a corresponding 250 mm centres of the tiller
lever or 200 mm to a corresponding 307 mm 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 RG10-70 gearbox has 6 positions to integrate an optional Jefa transmission autopilot drive unit. Integrating an autopilot drive in a steering system has never been so easy. The maximum input torque is 40.5 KgfM resulting in a maximum rudder torque at full rudder of 828 KgfM. The maximum rudder torque according to the CE rating is 291 KgfM midships and 552 KgfM full rudder (the CE regulations use a safety factor of 150%). This makes the gearbox suitable for boats from 45' to around 65'. Except for the input shafts 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. Please look at the mounting examples at the bottom of this page. Please click on the picture for a larger view. |
