RDG603A81
– Issue 2
Page 35 of 93
19. Hydraulic Drive Transmissions
If an engine is to have a hydraulic drive transmission attached to it instead of a conventional
marine gearbox, a number of points must be observed.
•
Bobtail engines (i.e. Engines supplied without a marine gearbox), normally do not have
a gearbox oil cooler fitted. However if a cooler is supplied, this will only be suitable to
cool a conventional marine gearbox.
•
Hydraulic drive transmissions generate far more heat than a conventional marine
gearbox. Therefore the size of the oil cooler installed must be calculated by the
hydraulic drive transmission supplier. This is to ensure it has sufficient cooling capacity
and is sized appropriately taking into account:
•
Maximum engine power.
•
High ambient summer air temperature.
•
Summer River/Canal/Sea temperature.
•
No additional restriction to engine coolant flow is present.
Skin tanks will also need to be increased by up to approx. 10% to dissipate the additional
heat generated, when a hydraulic drive system or hydraulic bow thruster is used.
Or
An additional separate skin tank of suitable capacity with separate water circulating pump will
need to be fitted for a hydraulic drive transmission.
Hydraulic oil coolers should be installed after the engine, not before. Coolers
that are installed before the engine will invalidate the engine warranty.
20. Hydraulic Pump Drive Option (Shire 70WB)
For SAE pump (9T)
If a hydraulic pump is required to drive items such as bow thrusters or hydraulic winches,
then the following parts are required to enable drive to be taken from the engine power take
off:
Part No 129980-26220 incorporates:
•
Cover: 121023-26070
•
Cover packing: 121023-26061
•
Bearings: 129900-26250 x 2pcs (included in the specialised gear case).
•
For high discharge volume: Above 20cc/rev.
Note: The pump will need to be sourced separately