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Mekanord Schematic
© 1998 Mekanord
1. Gravity tank - Stern tube. 2. Oil pump.
3. PTO gearwheel.
4. PTO clutch.
5. Hydraulic main clutch.
6. Pinion.
7. Input shaft.
8. Flexible coupling.
9. Hub.
10. Stern tube outboard seal.
11. Stern tube bushing.
12. Pins.
13. Cross head 14. Propeller blade.
15. Propeller shaft.
16. Oil lubricated stern tube.
17. Stern tube flange.
18. Stern tube inboard seal.
19. Tie rod.
20. Split muff.
21. Thrust bearing.
22. Servo piston.
23. Gearwheel.
24. Servo sleeve valve.
1. Gravity tank - stern tube:
The tank contains oil for lubricating and cooling the stern tube bearings and seals. The tank is to be mounted above the water line. Optional low level alarm.2. Oil pump:
The oil pump is direct driven and therefore runs as soon as the engine is started. The pump supplies the pressure for the pitch servo system and the hydraulic clutch. The bearings and the gearwheels are lubricated with oil from the pump.3. PTO Gearwheel:
The PTO gear wheels are offered with standard step-up ratios. It is possible to keep the PTO engaged separately from the propeller.4. PTO Clutch:
The PTO clutch is a hydraulic multi-plate clutch operated with a solenoid valve.5. Hydraulic Main Clutch:
The main clutch is a hydraulic multi-plate clutch operated with a 24 volt solenoid valve.6. Pinion:
The Pinion is a hollow bored case-hardened alloy steel helical ground gearwheel with spherical roller bearings. A large range of gear reduction ratios are available.7. Input shaft:
The input shaft is made of high tensile steel and goes trough the pinion and drives the oil pump, the PTO and the inner part of the main clutch.8. Flexible coupling:
The flexible coupling prevents damage caused by vibrations etc. The coupling is selected according to a torsional vibration calculation.9. Hub:
The hub is made of Mn-Bz. The shaft torque is transmitted either by a taper/key connection or by a forged flange on the propeller shaft. The hub is split at the blade center line for easy access to the blades. There is no critical seals in the hub design. The lubrication is by water emulsifying grease.10. Stern tube outboard seal:
The stern tube outboard seal is attached to the propeller shaft and made of rubber and vulcanized with a special material as wear plate that keeps pressing at the stern tube. The stern tube outboard seal is mostly hidden under a rope guard.11. Stern tube bushing:
The stern tube bushing is made of bronze or white metal.12. Pins:
The pins are mounted eccentrically to the shaft centerline. On each pin is fitted a slipper block that engages a slot in the blade foot. When the tie rod is moved ahead or astern the blades turn and the pitch changes .13. Cross head:
The tie rod cross head is threaded on to the tie rod which controls the ahead and astern position of the head.14. Propeller blade:
The propeller blades are manufactured in Ni-Al-Bz and are designed for either open or nozzle operation. The optimum diameter, pitch and area ratio are selected for each specific vessel. Skewed back blade designs are available to minimize vibration.15. Propeller shaft:
The propeller shaft is made of carbon steel. A certificate is always available. The shaft is hollow bored for the tie rod. Length of shaft shall be specified. Optionally the shaft can be delivered stainless.16. Oil lubricated stern tube:
The stern tube is made of steel and lubricated with oil under static pressure from the gravity tank. Optional water or grease lubricated stern tube. Length to be specified.17. Stern tube flange:
The stern tube flange is made of stainless steel.18. Stern tube inboard seal:
The stern tube inboard seal is normally the same type as the outboard seal having a water cooled seat.19. Tie rod:
The tie rod transfers the movement from the servo to the cross head.20. Split muff:
The split muff connects the servo and the tie rod.21. Thrust bearing.:
The trust bearing is a heavy duty spherical roller bearing22. Servo piston:
The servo piston changes the pitch and is controlled by the servo valve. The oil is let in trough the gearbox tie rod.23. Gearwheel:
The gearwheel is a helical ground gearwheel made of case-hardened alloy steel. A large range of gear ratios are available.24. Servo sleeve valve:
The servo sleeve valve's position is determined by a control lever on the gearbox housing.
Please see the AVAILABLE BOAT PLANS web page.
Home | Intro | Our Design Process | Stock Design Info | Motor Yacht Designs | Sailing Yacht Designs | Prototype Designs
Plans List | Articles | Our CAD Design Stream | Maxsurf | News..! | SITE MAP..! | Site Search | Design Team | Contact Us
