Hagglunds designs CBP motors for marine propulsion

Edited by the Engineeringtalk editorial team Feb 24, 2009

CBP motors from Hagglunds offer a speed range up to 320rpm dependent on the specific displacement, plus various sizes to choose from to suit the application.

These motors could provide benefits on propulsion systems on small to medium-sized vessels.

For example, the propeller would no longer have to be mechanically connected to the engine with a long rotating shaft.

It would be replaced with hydraulic pumps and just three hydraulic lines to the motor.

Therefore, all the engineering involved in designing and installing the long prop shaft and the cost of the shaft and bearings are eliminated.

This also frees up possibilities of positioning the engine and propellers anywhere in the vessel.

Hydraulically, a number of propellers can be powered from the engine.

Two or more engines can be used and the power can be shared between the drives.

This provides the opportunity to look at the basic vessel design and make improvements based on the flexibility of major components, for example, to improve the weight distribution.

It also means that all or some of the power can be diverted from the propulsion to other vessel requirements such as deck equipment when the full power of propulsion is not needed.

More than one engine offers possibilities for redundancy and therefore extra security if needed.

If the pumps used are variable displacement, the speed can be controlled independently of the engine, which would run efficiently at a fixed speed and with two propellers.

The hydraulic motors can even be used in submerged conditions and are maintenance free, providing long and reliable life.

They are also quiet compared to mechanical drives because there are no high-speed elements involved as gearboxes are eliminated.

The motors provide high torque without the need of speed reduction units.

The mechanical efficiency of these motors is approaching 98 per cent, similar to that of a roller bearing.

The motors and pumps are available on short lead times and Hagglunds has a worldwide network of sales and service facilities to offer support.

Hagglunds motors offer almost negligible inertia, which brings a response to the drive to give fast stopping in emergencies or for starting and stopping frequently with controlled ramp up and down times.

The high torque from the motors is available irrespective of the speed, so high starting torque is a standard feature.

It may also be possible to improve propeller design to take advantage of this feature to operate at lower speeds and therefore lower noise levels.

The company said that the drive arrangement is simple and installation is easy.

With flexible hoses connecting the motor, it is also possible for the drive to move during operations so opening the possibility for the propeller to slew or move up and down with the close coupled drive.

This technique is already used, for example, on Dredging cutterhead drives.

Hagglunds motors are manufactured in Sweden to ISO9001 and environmental standard ISO14001.

They are used on all kinds of deck equipment, winches, carousels, mud pumps, drilling equipment, cutterheads and tidal and wind energy projects.