What are main reduction gears?
A main reduction gear (MRG) is a critical element of a ship’s propulsion system, the function of which is to connect a ship’s engine to its propeller shaft. The MRGs will be branded by Timken’s Philadelphia Gear subsidiary, a company it acquired in 2011 for $200 million.
What is reduction gear loading?
marine. Equipment used to convert the output shaft revolutions of the main engine to those required to rotate the propeller. Gearboxes consist of meshing teeth on pinions and wheels which transfer power from a drive shaft to a driven shaft and reduce speed.
What is a locked train reduction gear?
LOCKED TRAIN. -In the locked train type of double reduction gearing (fig. 7-2), each high speed pinion meshes with, or drives, two first reduction gears and thus transmits power to two second reduction pinions.
How does reduction gear work?
A reduction gear is an arrangement by which an input speed can be lowered for a requirement of slower output speed, with same or more output torque. The high speed incoming motion from the wheel work is transmitted to the set of rotating gears, wherein the motion or torque is changed.
What is the point of gear reduction?
While in many applications gear reduction reduces speed and increases torque, in other applications gear reduction is used to increase speed and reduce torque.
How does a main reduction gear work?
Reduction drives operate by making the engine turn a high speed pinion against a gear, turning the high rotational speed from the engine to lower rotational speed for the propeller. The gears used in a ship’s reduction gearbox are usually double helical gears.
How are reduction gears used in ship propulsion?
The most common means of obtaining the required propeller rpm for ship propulsion is by use of reduction gears. The use of reduction gears is by no means limited to ship propulsion. Other steam turbine-driven machinery such as ship’s service generators, air compressors, and various pumps also have reduction gears.
Who is the world leader in reduction gears?
RENK AG is the world leader in the design and manufacture of advanced reduction gear systems for combined propulsion systems supplied to the US Navy’s Freedom-Class and Independence-Class Littoral Combat Ships and the Coast Guard’s National Security Cutter. In addition, RENK supplies reduction gears for other naval…
What are the different types of reduction gears?
There are two other arrangements of double reduction gearing in use-the ARTICULATED GEARING and the NESTED GEARING. ARTICULATED. -Typical articulated propulsion reduction gears (fig. 7-3) have two first reduction pinions (high speed), two first reduction gears, two second reduction pinions (slow speed), and a main gear.
How many reduction gears are in a locked train?
LOCKED TRAIN. -In the locked train type of double reduction gearing (fig. 7-2), each high speed pinion meshes with, or drives, two first reduction gears and thus transmits power to two second reduction pinions.