Electric clutch for transmission systems

Jefa series 100 & 200 electric transmission disengagement clutch

The Jefa disengagement clutch offers the possibility to disengage the transmission steering system from the rudder with a power consumption of only 0.7 amps (12 & 24 volts). There are good reasons to do so:
1). Lower power consumption of the autopilot drive unit. As the steering wheel(s) and transmission parts don’t have to be speeded up and slowed down which each autopilot correction.
2). Less wear in the steering transmission parts. On most blue water cruisers the autopilot is steering the yacht the vast majority in time.
3). More safety in the cockpit. The wheel(s) will not rotate randomly any more under autopilot cruising and there is no risk to get hands and arms trapped in the spokes, especially when there are kids on board.
4). On twin wheel boat you can disengage one wheel and steer on the other so you don’t have the annoying “echo effect” – when you do a quick rotation on one wheel, a second later you feel the echo from speeding up and slowing down the other wheel.

100 series transmission clutch

The Jefa CL10 is designed to fit the mounting surface for transmission drive units which makes an opportunity to easily install the clutch on existing, as well as new steering systems. It can be delivered for 12v as well as 24v disengagement and manual disengagement. The manual version is should be installed with engine control cable and handle.

Gallery

200 series transmission clutch

The construction:

The above cross section shows the construction of the electric clutch. Under normal power off circumstances (as in the above illustration) the clutch pin, which is connected to the right shaft, is connected to the left flange and shaft. All forces are now transmitted through the unit with a neglectable amount of friction and play.
As soon as the unit is powered, only 0.7 amps 24 volts is enough to disengage the clutch pin. Both flanges are now not engaged any more so the right shaft can rotate independently from the left.

The electric clutch should be operated by a separate button near the pedestal and should not be automatically switched by the autopilot. Standard the electric clutch has 18 clutch pin hole, so there is one engagement position every 20° rotation.