Page 14: of Marine News Magazine (February 2012)

14MNFebruary 2012 TECH FILEBacked by the combined experience of more than 100 years of experience in design, installation, and testing of marine propulsion systems, Sound Propeller Systems is introducing a new, state-of-the-art azimuthing SPS 1500 Z-drive unit. Plans are also in the works to produce larger models in the 2500 ? to ? 3500 HP range. Sound Propeller Systems technicians already perform a wide range of service needs include shafting, fixed and control- lable pitched propeller systems, bow thrusters, stern tube seals, custom alarm systems, mechanical systems, pneu-matic systems, hydraulic systems, and electronic systems. The breadth of that knowledge is directly reflected in their newest endeavor. UPAND RUNNINGWith their first entry targeting the 1500 HP market ? harbor assist, towing, ferry, military, offshore supply, DP, and fishing industries ? the new Z-drive started from a concept borne 3.5 years ago. Notably, the effort is 100 percent internally financed and all hardware, with few exceptions, is U.S. built. In January, Sound Propeller managers told MarineNews that the prototype model had already been completed with a second unit expected in place within the next six months. The process to achieve ABS-type approval is now underway. As they ramp up to market the new product, they also promised a ?full stop? shop for emergency service. In tandem with and playing a direct part in the development of their own Z-drive model, is Sound Propeller?s own unique test stand. A patent has been applied for and the unit is adjustable to fitother makes and models of drive units. The unique tool might someday constitute the model for all Z-drive test- ing equipment. In the meantime, Sound Propeller has made good use of it in the development in their prototype model.DESIGNAND MAINTENANCEThe single lube/hydraulic fluid is circulated through a lubricant filtering and desiccant system whenever the engine is running. When the vessel is not in use, an aux- iliary pump can circulate the fluid to keep condensation from fouling the internal parts. This circulation system is designed to pick up the lubricant from the bottom of the lower unit to assure that any contaminants or water are fil- tered out of the system. With ease of access and mainte- nance in mind, the new drive unit features an externally mounted clutch on the opposite side of the upper gear box from the input flange. This gives access for any needed clutch service without disturbing the input shaft. Beyond this, the bearing assemblies are installed in cartridges which allows the bearing pre-loads to be set in a shop environment. According to Sound Propeller technicians, this serves to greatly simplify bearing replacements in the field. The service technician can set the correct gear con- tact with shims on the cartridge flanges rather than shim- ming each bearing as it is installed. Spare bearing car- tridges and gears on the shelf will assure minimal down time when bearing or gear replacements are needed. NUMEROUS ADVANTAGES Sound Propeller Systems lists many advantages to their new design, among them (a.) improved hydronamics, (b.) ease of overhaul, (c.) cartridge loading (removal of com- ponents in one piece ? plug and play and (d.) considerablyreduced down time in time of maintenance and/or repair. Setting out to design a Z-drive unit which can excel in efficient performance by its hydro-dynamically considered design of the lower unit and appendages, computer model flow tests guided the design of all parts with a view to cut- ting drag which will save fuel every time the vessel is mov- ing. The manufacturer also reports that the low drag noz- zle design and highly efficient propeller design are an important combination that helps get the most propulsive thrust out of each ounce of fuel. An additional benefit of the hydro dynamically pleasing design is a reduction in vibratory issues and cavitation caused by disturbed water flow around the unit. Sound Propeller?s new entry into the crowded z-drive field is exciting for more than one reason, but of particular interest to domestic workboat operators, a state-of-the-art U.S.-built unit provides options, compe- tition and perhaps a reason to do some shopping around. And who wouldn?t be in the market for a more efficient, cost-saving and high tech improvement to their propul- sion systems? New Z-DriveFrom Sound Propeller ... Robust, Service Friendly and Made in the USA MN#2 (1-17):MN 2011 Layouts 2/3/2012 1:34 PM Page 14