Bevel reduction gearbox 1:6.7


Jefa BRG10-67 bevel reduction gearbox
The BRG10-67 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 BRG10-67 has a gear reduction of 6.7:1. This results in 2.4 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 (2.9 turns with one step ratio and 3.6 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 760 KgfM. The maximum rudder torque according to the CE rating is 278 KgfM midships and 506 KgfM full rudder (the CE regulations use a safety factor of 150%). This makes the gearbox suitable for boats from 45' to around 60'. Except for the input shaft and the gears, the complete gearbox is machined out of solid aluminium 6082 for maximum strength and minimum weight. On top of the gearbox, two multi position gearbox stops are fitted. These stops are primarily designed to protect the gearbox and steering system and not as rudder stop. When these stops are used as rudder stop, one should realise that this will leave the draglink and tillerarm unprotected. 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.
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Jefa transmission bevel reduction gearboxes

Part No.

Description

Price in Euro

BRG10-67

Bevel reduction gearbox 1:6.7 including output lever

1.320

BRG10-67 mounting examples
The layout below shows a typical installation of a BRG10-76 gearbox in a centre cockpit boat. The gearbox is placed next to the rudder shaft at an offset of 106 mm. This offset is necessary to achieve a correct wide angle geometry (click here for more information). A good confirmation of the correct geometry is to check if all 4 endpoints of the lever pins are in one line (see the green line in the layout).


BRG10-67 mounting examples
The layout below shows a typical installation of a BRG10-76 gearbox in a centre cockpit boat when there is no space next to the rudder shaft, or when the gearbox would be mounted too high to get the torque tube underneath the bed. The gearbox is placed in front of the rudder stock at an offset of 106 mm. This offset is necessary to achieve a correct wide angle geometry (click here for more information). A good confirmation of the correct geometry is to check if all 4 endpoints of the lever pins are in one line (see the green line in the layout).