Nordberg GP300 Top Bearing Seal Structure Improvement

One of our customers started to use Nordberg GP300 cone crusher since the 2004 year. The machine has the characteristics of large processing capacity, simple operation, convenient maintenance, and high automation. However, after several years of use, some problems have arisen, requiring frequent maintenance and replacement of parts, which not only wastes a lot of labor and material resources, but also requires the entire production system to be shut down, which affects normal production.

The Problems

The feed plate of the GP300 cone crusher and the upper frame are fixed by four M20 screws with O-rings for sealing the end faces between the end faces. Check the following picture:

Nordberg GP300 Top Bearing Seal Structure

  • 1. Feed Plate       2.4- M20 Screws       3.O-rings      4.The Upper Frame       5. The Upper Bushing    6.Mainshaft

The fixing of the upper frame and the distribution plate of the GP300 cone crusher is unreasonable. Under the vibration of the ore impact and the crushed ore of the equipment, the bolts are subjected to large force, which is easy to loose or even sheared, resulting in the separation of the ore. The disc and the rack are loose and create a gap. The O-ring seal loses its sealing effect, and mud, slurry and dust enter the upper cavity through the gap (the grease is stored in the cavity), causing rapid wear of the upper shaft (with the jacket) and the upper bearing. The separation disc is located in the feeding chamber of the crusher. It is difficult to find that the distribution disc is loose when the equipment is running, so it cannot be processed in time.
When the wear reaches the limit, the equipment vibrates greatly, the upper part of the main shaft is not effectively supported, and the crushing capacity is greatly reduced. The equipment has to be shut down for repair; when the wear exceeds the limit, the large axial force generated by the crushing causes the main shaft to tilt too much, crushing the eccentricity The upper part of the copper sleeve causes the copper sleeve of the frame to rupture. In recent years, an average of one upper bearing needs to be replaced every month. Every two months, the upper bearing housing and the parts such as the separation plate need to be replaced. In less than one year, the eccentric copper sleeve and the frame copper sleeve need to be replaced.
After a series of accessories such as the upper bearing are worn, the moving cone is excessively vibrated, causing the matching cone surface of the upper frame and the lower frame to wear.

Improvement Measures

The mine has improved the bearing seal structure of the cone crusher, as shown in Figure 2. Machining 1 piece of M440×8 mm×55 mm left-hand locking sleeve and welding on the upper frame. The left-hand locking sleeve and the moving cone rotate in opposite directions. Only the locking will not loosen during operation. A sealing groove is formed on the upper surface of the locking sleeve, and the oil hole is opened on the side for lubrication. Install a lock nut on the lock sleeve and tighten to fix the splitter disc. Even if the splitter disc is loose, the slurry will not enter the grease chamber at the top of the spindle.

Figure 2

  • 1. Feed Plate       2.4- M20 Screws       3.O-rings      4.The Upper Frame       5. The Upper Bushing    6.Mainshaft

After the improvement, the vibration of the equipment is reduced, the wear caused by the vibration of the upper and lower frames is reduced, and the local axial pressure of the moving cone to the eccentric copper sleeve and the copper sleeve of the frame is also reduced, and the crusher is operated more. It is stable and avoids cracking of the eccentric copper sleeve and the frame copper sleeve.

The Result

The mine improved the top bearing seal structure of the GP300 cone crusher in November 2009. The equipment has been operating normally, and the parts have not been replaced, saving a lot of maintenance time and achieving good economic benefits. 1 year can save 10 pieces of upper bearing, totaling 50,000 yuan; 4 bearing blocks, totaling 20,000 yuan; 3 pieces of main shaft sheath, totaling 15,000 yuan; 4 pieces of mining plate, totaling 20,000 yuan; eccentric copper sleeve 1 A total of 90,000 yuan; a rack of copper sleeves, a total of 110,000 yuan. The total cost savings is 315,000 yuan. The improvement of the sealing system is only 28,000 yuan.

 

 

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