|
LOMBARDINI SAILDRIVES
The new Lombardini Saildrives have been developed from years of experience with sailboat racing. This experience in collaboration with many professional skippers helped them to devise a transmission and saildrive unit which features the essential requirements of sturdiness and reliability whilst, at the same time, offering the minimum water resistance during sailing.
An Edge to Cut the Sea
The shape of the submerged part of the drive has evolved to incorporate an excellent hydrodynamic profile with an extremely low drag coefficient, where the drives section and chord are reduced to the minimum, for optimum boat speeds between 4 and 12 knots. In order to have the minimum overall dimensions in the lower part of the drive, bevel gears with a ratio of 1:1 have been utilized moving the rpm reduction on the upper part of the gear.
The axial thrust is handled by a special conical bearing arrangement. To make the installation easier, the drive has its own built in sea water inlet and is supplied with a seacock.
Sealing Membrane
The sealing gasket is made from a special rubber resistant to both hydrocarbons and sea water. Its special shape in combination with the strength of the rubber ensure maximum life and durability and allows the drive to move independently from the hull, which promotes a pleasant sailing environment with no vibration being transmitted to the boat.
Weight
Particular attention has been paid to weight reduction, in anticipation of applications on board racing boats. Reinforcement ribs have been employed to increase the mechanical strength of the drive housing without reducing reliability.
Gears
Great attention has also been paid to the design of the gear teeth since mechanical noise mostly depends on the profile of the gears adopted.
Conical gears with helical teeth incorporating a special involute shape, which allows continuous contact between the gear tooth surfaces, reduce noise. The Gleason method is used during manufacture to guarantee minimum tolerances on the special alloy steel teeth, which are carburised and hardened for maximum life.
Reversing Gear Safe and Reliable
The clutch assembly has been developed to ensure soft and precise gear engagement. A technologically advanced metal-spray surface treatment on the bronze clutch cone allows the oil to drain quickly from the clutch when manoeuvring, ensuring smooth, positive shifts.
Lubrication
Lubrication throughout both the upper gear mechanism and the lower part of the drive is assured by utilising a single oil path. The oil is circulated by the pumping effect of the special gear profile. The large 2.8 litre oil sump in the drive allows longer intervals between servicing. Oil cooling is assured by the contact of the drive with the seawater.
Protection Against the Elements
The drive is protected against corrosion by the use of a special aluminium alloy with a reduced copper content, and stainless steel is employed for all shafts, nuts and bolts. Two electronic treatments, before and after machining, followed by an electro deposition paint process and two coats of special marine paint, protect the external surfaces. An extra large zinc-plate, directly mounted on the drive provides protection against galvanic corrosion. |
