Marine Gearbox Repair Service

The overwhelming most engine-driven art use propellers to convert the energy of the engine motor to useful work.

There are many alternatives which might have advantages of specific applications, but propeller systems are good all-rounders that are sensibly cheap, simple, reliable, productive and simple to use.

It’s also very helpful to have the ability to reverse the path of rotation, to provide the astern capacity to stop the sailboat or make it go backward, or even to fit counter-rotating propellers on the twin-screw motorboat.

Again, there are other alternatives for an instant as variable-pitch propellers whose cutting blades were rotating on the hub, scoop-like deflectors, or even sailboat engines that may be quit and restarted on the contrary direction, but the most popular design is a reversing gearbox.

Reversing gearboxes

Two gear wheels, whose tooth mesh together so when one changes, the other must flip as well. Small gear has nine teeth, so if it’s turning at 1000 rpm, its tooth is moving at 9000 teeth per minute. The bigger wheel is double the scale and has 18 teeth, so although its tooth must be moving at 9000 pearly whites per minute, which means only 500 rpm. Take note of, too, that if the small steering wheel is turning clockwise, the bigger steering wheel must be turning anticlockwise.

Quite simply, by using a 9-tooth wheel to operate a vehicle an 18-teeth steering wheel, we’ve halved the rate doubled the torque and reversed the way of rotation.

Simple gearboxes

Real vessel gearboxes look more difficult but rely upon exactly this basic principle. In fact, the key difference between your simple gear coach and the Volvo MS2 would be that the MS2 uses cone-shaped bevel gears, so that but the source shaft is horizontal, the central driven shaft is vertical.

The bevel gear on the insight shaft becomes two slightly much larger bevel gears that spin easily on the vertical shaft. Some may be driven by the very best of the source gear and the other by underneath then it, so they turn in opposite guidelines.

However, they will be the same size as the other person, so they flip at the same quickness.

Between the gears is a slipping clutch assembly, molded like two shallow cones installed base-to-base on the shaft. Ridges called splines on the shaft, and corresponding grooves in the clutch ensure which it can simply slip along, but can’t transform without turning the shaft as well.

Moving the gear lever slides the clutch up or down, so any particular one of the cones engages into a matching hollow in another of the content spinning gears, which locks that gear to the shaft.

In the bottom of the shaft, a comparatively small bevel gear engages with a much bigger gear on the result shaft, to provide a horizontal result, at a lower acceleration of rotation.