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Part No: PRM-280DP3
Full hydraulic operation, lightweight, compact & rugged. PRM Newage introduced the 280DP model as a replacement for the 260D, While ratios and interfaces remain the same, the 280DP has an increased... Read more
Full hydraulic operation, lightweight, compact & rugged.
PRM Newage introduced the 280DP model as a replacement for the 260D, While ratios and interfaces remain the same, the 280DP has an increased power rating and has also been fitted with a live PTO (Power Take Off).
The PRM280 marine gearbox is purpose built for use in both pleasure craft and commercial boats; its twin countershaft design provides separate oil-operated multi-disc clutches (which need no adjustment) for ahead and astern drive allowing full rated power to be transmitted continuously in either direction.
The PRM280 is offered in two different configurations; power take off (PTO / PRM280DP) and with offset output shaft (PRM280).
A choice of 1.96:1 and 2.94:1 reduction ratios is available; each will provide left-hand or right-hand propeller rotation in "ahead", making the PRM280 particularly well suited to twin engine installations.
The gearcase is constructed of high grade cast iron, internally ribbed for rigidity and strength, and consists of two separate halves to facilitate servicing, the oil pump and hydraulic control valves being externally mounted for easy accessibility.
The PRM280DP live PTO gearbox specifically designed for driving hydraulic pumps to SAEJ774C series B specification. The maximum power which can be transmitted is 22kW (29.5hp) per 1000 rpm.
The hydraulic operating system functions on normal lubricating oil of the same viscosity as that used in the engine, avoiding the need to use automatic transmission fluid, and ensures rapid response to movements of the operating lever for good boat handling. The operating lever has a positive neutral detent and is suitable for use with proprietary single lever remote control operating systems.
Robust and reliable, the hydraulic system is nevertheless provided with a mechanical lock-up device for added security, so that in the unlikely event of hydraulic failure the boat can be brought safely back to port. Access to this device is via a detachable cover located on top of the main gearcase.
A trolling valve can be fitted. This is electronically operated which allows variable speed of the propeller to zero whilst allowing a maximum engine speed of up to 1200 rpm.
It is essential for the engine, transmission model, reduction ratio and propeller size to be correctly matched so that the engine can attain its rated speed appropriate to the relevant service classification without labouring.
It is also necessary to ensure the torsional compatibility of the complete propulsion system from engine through to propeller, since disregarding this may result in gear noise, particularly at low speed operation, and may even result in damage to the engine as well as the transmission components.
Minimum - 20.00 bar (290 PSI), Maximum - 22.06 bar (320 PSI). Two tapped holes 1/8" BSP on the top, and M18 on the side of the valve block are provided so that the pressure gauge can be fitted if required.
The normal operating temperature of the oil should be in the 50°C - 80°C range and should not be permitted to exceed 90°C. An oil cooler is necessary to ensure that correct operating temperatures are maintained, and the valve block is provided with two 3/8" BSP connectors to allow it to be fitted.
Both ahead and astern thrust is carried by the output shaft bearings which are of adequate capacity for all factory approved ratings.
Propeller Free Wheeling
The PRM280 output shaft can be rotated continuously with the gearbox in neutral. It is therefore not necessary to fit a propshaft brake in such applications.
PRM280 Gearbox spline: 10 teeth SAE 1". PRM 280 Gearbox coupling: 5", 4 holes, 4-1/4" PCD, 2-1/2" female register. Oil Capacity: 1.5 litres (2.64 pints).
|Capacity||Oil Capacity: 1.5 Litres (2.64 pints) (plus the amount require to fill the cooling circuit)|
|Construction||High Grade Cast Iron Gearcase|
|Ratio Ahead Stern||2.94:1|
|Nominal Power Rating Pleasure||3.93 BHP / 100 RPM|
|Nominal Power Rating Light Commercial||3.79 BHP / 100 RPM|
|Nominal Power Rating Heavy Commercial||3.58 BHP / 100 RPM|
|Gearbox Spline||10 teeth SAE 1"|
|Gearbox Coupling||5", 4 holes, 4-1/4" PCD, 2-1/2" female register|
|Approximate Dry Weight||54kg (120lbs) (excluding adaptor, drive coupling and oil cooler)|
|Shaft Arrangement||Drop Centre|
|Hydraulic or Mechanical||Hydraulic|
|Country of Origin||United Kingdom|
|Gearbox Model||PRM 280DP|
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