Slewing bearing for excavator

Ring for construction machinery is boasts for the domestic and world class customers from gaining the trust.

It can be applied for the best quality excavator slewing bearing from 1 tonto 80 tons excavator, and we respect customer requirements and offers, too. In addition to the main chapter of the construction site, tower crane, truck crane, and marine crane, crane for special use, parking facilities, a large crane hoist can all apply for the slewing bearings.

l Description l

Slewing ring for excavator, crane and wind power generator.
Slewing rings are usually used for low revoluaion while shaking and strained with an enormous axial force, moment and in some parts with radial force simultaneously.
Consequentiy the requirements for loading are stricter than ordinary bearings. If the selection of the bearings.
If the selection of the bearing has been wrong it will cause a great damage. Hence it is necessary to evaluate the exact forces acting on the slewing ring and to select the suitable slewing ring.

l The type of load l

• Axial load(Fa)
  It is the load acting vertically on the slewing ring.
  It means the total weight on it, that weight of the upper rotary body, the weight of work loading, balance weight etc.
  
  
  
• Radial load(Fr)
  It is the load acting horizontally on the slewing ring.
  It means the load of the gear, force of the wind, in the case of a power shovel.
  It is the load of the excavation and in the case of a crane. It is the inertia of the upper body.
  The radial loads are usually so small, that they can often be neglected.
  
  
  
• Moment(M)
  It is the resulting load if you multiply Fa and Fr with the distance between the acting points of Fa and Fr and the center of the slewing ring.

l Procedure for selecting the slewing rings l

After Proceed calculations of the loading axial load (Fa) and the radial load (Fr)(moment is already known). Now a suitable slewing ring for your purpose is to be selected.

• According to the structure of your machine decide between the internal gear or exernal gear, and then select the appropriate madel for calculation of the Loads among the preceding models(see page 14-15).
• Based on the calcuate the composite axial load(Fa')
  
  
  SISD type : Fa'=Fa+5Fr
  SISR type : Fa'=Fa+2Fr
  SISC type : Fa'=Fa
  
  Fa' : composite axial load
  Fa : axial load
  Fr : radial load

• According to the type of your machine choose a loading line for light work or heavy work.
  (refer to page 33-39)
• Take the composite axial load(Fa') as X-coordinate and moment (M) as Y-coordinate and get the point of intersection.
• The slewing ring to be chosen can be obtained from the tables on pages 20-31.

l Lubrication l

Lubrication is an important factor that can strongly affect the function and the life of the slewing ring.
Therefore it is necessary to select lubrication oil and the lubricating system suitable for your application.

• Lubricating oil
  Because of the application and the structure of bearings grease is usually used fo slewing rings.
  
  
• Selection of grease
  Grease is to be chosen among the following categories.
  -In case of heavy load or loading with impacts a gease with an excellent endurability under pressure is to be chosen in order to prevent damage to the oil film.
  -In case of long service Interval a grease with an excellent chemical property is to be chosen for safety. To ensure long-term running without failure.

l Tolerance of tangential force for gear l

Calculation of the tolerance tangential force for the gear under normal working conditions.
The tolerance can be obtained according to the various factors for gears listed in the table on pages 20-31.
(MODULE, number of tooth, Width of tooth) and figure 5-1 and figure 5-2.
If the actual tangential force exceeds the tolerance of the circumferential velocity is to high, please contact Shin il.

l Specification l

Bearing used