Gear Unit

Selecting a Gear Unit

Popular Gear Units

Installation

A gear unit is a set up of machine where a set of gears normally having different diameters are positioned. It must be understood that gear units are not standalone machines. In fact it is the medium to connect driven and driving machines. Consequently, torques and rotational speeds gets changed and adapts perfectly to the necessary machines. The Gear Units are a popular feature for most of the high-speed rotating machineries. These includes centrifugal pumps, turbine generators, compressors etc. A gear unit can change the rotational number of the shafts. This it does by employing a gear coupling with varying number of tooth. A gear unit is also used in choosing the requisite speed for a driven machine.

These days high speed gear units are having a wide use in numerous kinds of drivers or driven machines. The efficiency and out put of a gear unit is basically determined by factors like splash losses, bearing as well as gearing friction. The following image shows a typical gear unit which has employed double helical gears are installed.

Whole view of gear unit

Inside view of gear unit

Parameters in Selecting a Right Gear Unit

• Gear wheels
• Gearing quality
• Casting Material
• Bearing Shafts
• Lubrication
• Seals
• Temperature

Popular Gear Units
Some of the popular gear units are discussed here. It must be noted here that only a few types of gears are discussed here and there are many more types of gear units available:

• Mill Gear Units
  • Ball mills
  • Roller mills
  • Roller presses
• Turbo gear units
  • Axial compressors
  • Centrifugal compressors
  • Centrifugal pumps
  • Generators
  • Piston compressors
• Marine Gear Units
  • Diesel engine propulsion lines
  • Gas turbine propulsion lines
  • Steam turbine propulsion lines
  • Electric motor propulsion lines
  • Combined propulsion lines
• Planetary Gear Unit
• Reduction Gear unit

Installation of a Gear Unit
For assembling of the gear units in a perfect manner, it is important the oil fittings, like vent, gauges or drain are easily accessible. It is also important to make sure that enough fresh air is available for cooling. The gear unit needs to assembled in the order mounting position, this results in proper lubrication and ventilation during the process of operation. Installation aspects of Gear unit must adhere to the following points of caution:

• In case of mounting the machine shaft care must be taken so as to avoid direct mounting of gear unit to a base plate.
  
  
• In case of shrink-on disks, precaution must be taken so as to avoid tightening the tensioning screws before a shaft has been installed. Not adhering to this instruction may result in eventual deformation of the hollow shaft.
  
  
• Another point of caution is supplementary parts should not be hammered on to the shafts. Doing otherwise may result in damaging of tooth profiles, rolling bearing or locking rings.