(ZF makes a two-speed marine gear.) … In some installations counter-rotation of the propellers is actually accomplished by simply swapping the linkage so that the opposite gear set is engaged when the lever is moved. The other function of the marine transmission is to set the ratio between engine rpm and propeller rpm.
What is a ZF Marine transmission?
ZF Marine provides transmissions (reversing, non-reversing and hybrid), propellers, thrusters, steering systems and electronic control systems for a comprehensive range of applications with a power range from 10 to 12,000 kilowatts in commercial and fast crafts as well as in pleasure crafts and yachts.
How does a ship gearbox work?
Usually the gearbox is a basic one. Commonly controlled by a single lever at the helm the skipper is able to select forward, neutral & reverse. … Moving the lever into the ahead or astern position engages the appropriate gear which drives the propeller shaft, which has the propeller attached to the other end.
How does a PRM gearbox work?
In this type of hydraulically operated gearbox the input shaft is turned by the engine and drives the layshaft through a pair of large gear wheels. … On this gearbox the control lever directs oil under pressure (from an oil pump driven by the layshaft) to one or other of feeders on the shafts.
How does velvet drive transmission work?
Velvet Drive transmissions Only turn the same direction as the motor [while in forward gear] If you try to get forward motion with an opposite hand prop by running in reverse, your Transmission will be Very Short lived – Reverse gear is designed only for short, low speed operation.
What are ZF gears?
ZF provides a complete line of heavy duty gearboxes with cast iron housing and deep ratios for all types of vessels from tugs to tankers, fishing boats to factory ships. These transmissions can be matched to all types of ICE (internal combustion engines) up to 12.000 kW power.
When did ZF buy Hurth?
In the marine business, ZF also bought HURTH Marine Gear S.p.A., headquartered in the northern Italian city of Arco, in January 1995.
Why do boat engines not have transmissions?
Boat engines don’t have transmissions because they add a lot of undesired complexity for a minimal speed gain. Usually, the propeller doesn’t turn at speed equal to its engine; if it does, it cavitates & reduces its life span. Adding gears increases speed, which increases cavitation, so no gears.
How does a outboard gearbox work?
How It Works: The gearcase takes the vertical rotational power from the driveshaft and converts it to horizontal rotational power along the prop shaft and to the propeller. The gearbox also dictates which direction the prop shaft and propeller rotate in. The drive shaft enters the gearbox and ends at a pinion gear.
What is a Twin Disc gearbox?
Twin Disc industrial gearboxes are engineered to withstand the most rigorous applications on Earth. Their modular design features clutchable input, housing with drive plate or stand-alone shaft input. Options include reduction and increaser gear ratios on outputs, as well as output rotation options.
How do I know if I have a PRM gearbox?
A: The serial plate on the top of the gearbox will say what model of PRM gearbox you have. The first line will have the serial number and the second line is the PRM model number and ratio. An example of modern plates will say “280D2. 5” which means that the gearbox is a PRM280 with a drop centre and a 2.5:1 ratio.
What oil goes in a PRM gearbox?
Oil. Hydraulic gearboxes, we recommend 15W40 mineral oil (not synthetic) for typical use. For extreme temperatures see owners handbook. Always check the oil level with the dipstick screwed down.
What is hydraulic transmission?
hydraulic transmission, device employing a liquid to transmit and modify linear or rotary motion and linear or turning force (torque). … By means of a scoop tube, the quantity of liquid in a coupling and the speed of the driven shaft can be varied.