Vertical shaft impact crusher, commonly known as VSI sand making machine in the industry, is one of the major equipment for the production of mechanical sand, which has many advantages, but due to the relatively complex structure of the VSI sand making machine, the high failure rate of the equipment has also been a thorny problem plaguing some manufacturers and the end users. As the VSI sand making machine work mainly from the high-speed rotor system, and the key to the efficient operation of rotor system is the rotor bearing, so the bearing in a certain way determines the efficiency of the sand making machine. The following article will have detail explanation for the common problems and side effects on the bearings.
1. The machine body is not steady, vibration or swing too much
A. Causes
-Wear parts on the rotor is worn out, cause unbalance of the rotor.
-Feeding size is too large or uneven.
-There are obstructions in the rotor working orbit, it makes feeding material uneven and swing.
B. Effects on bearings
The unbalance of the rotor will cause large vibration and bias load on the bearing, it will lead to abnormal temperature rise, creep, wear and premature fatigue of the bearing.
C. Solutions
-Replace wearing parts and make the VSI sand making machine rotor balanced.
-Strictly control the feed size, which should not exceed the maximum allowed by the equipment.
-Take out the obstructions in the rotor working orbit and clean the crushing chamber frequently.
2. Abnormal sound during the equipment work
A. Causes
The connecting bolts inside the sand making machine or the lining plate, rotor body and other wearing parts are loose and fall off.
B. Effects on bearings
The strike plate or connections bolts on the rotor loosen problem will also cause the unbalance and vibration of the rotor, resulting in abnormal bearing temperature rise, creep, wear, advance fatigue and other problems.
C. Solutions
Immediately stop the machine and re-tighten and install the parts that are loose or have fallen off.
3. The bearing operation is not flexible
A. Causes
The bearing seal cover of the sand making machine enters the material and other impurities.
B. Effects on the bearings
Foreign matter bite into the seal cover will lead to increased resistance to shaft rotation, and even sudden clamping or deceleration and other phenomena, resulting in abnormal impact on the bearing, if the foreign matter fine into the bearing, but also lead to lubrication failure, bearing wear, temperature rise, clamping or even fracture.
C. Solutions
Open the seal cover, clean the impurities
4. Bearing temperature rising
A. Causes
-Seal cover and seal damage, resulting in the entry of dust and impurities in the bearings.
-Insufficient lubricant, deterioration, substandard quality of grease, improper selection of grease grade.
-Bearing overdue service, worn out.
B. Effects on bearings
VSI Sand making machine bearing need to maintain a reasonable clearance during use, when the bearing temperature is abnormally high, it will directly lead to the elimination of the internal clearance of the bearing, resulting in the shaft lock-up, or structure broken, then further lead to serious consequences.
C. Solutions
-Clean the impurities, clean the bearing, replace the worn seals.
-Choose lubricating grease with suitable viscosity, add grease according to Deya Machinery’s operation manual, check the properties of lubricating grease regularly, and replace the aging grease in time.
-Regularly check the use of bearings, record the bearing run time, timely replacement of overdue bearings, and reduce the safety risks of sudden failure.
5. Shaft upper and lower end bushings and labyrinth cover damage
A. Causes
Up and down move friction causes the heat between the upper and lower bushings, as time goes on it causes damage.
B. Effects on bearings
Wear of the bushings and labyrinth cover will lead to seal surface failure, the dust and other impurities will enter the seal, which further cause damage of the oil seal, resulting in dust and metal powder enter the bearing, thus lead to the temperature rise, clamping or lock-up.
C. Solutions
Replace the new upper and lower seal cover or sleeve.
6. Oil leakage from the upper and lower ends of the shaft
A. Causes
Labyrinth seal failure leads to the entry of dust, dry wear at the oil seal, resulting in seal failure at the joint of the oil seal and the sleeve, the gap increases thus causing oil leakage.
B. Effects on bearings
The direct effect of oil leakage is that the dust will enter the bearing, long-term oil leakage will lead to insufficient lubrication and oxidation of grease, resulting in bearing wear, temperature rise and other abnormalities.
C. Solutions
Replace the worn oil seal and sleeve, and check whether the bearing is damaged.
7. Discharge size becomes large
A. Causes
-Long operation of the equipment leads to the loosening of the v-belt in the transmission part.
-The feed size is too large.
-The rotor line speed is unreasonable, the efficiency becomes low.
B. Effects on bearings
The change of rotor speed and excessive feed size will lead to abnormal vibration and creep of the bearing, thus making the bearing fatigue in advance.
C. Solutions
-Adjust the v-belt tightness to avoid slipping.
-Strictly follow the feeding requirements of the VSI sand making machine. If the feeding is too large, it will cause the equipment to swing too much, and if the feeding is too small, the collision crushing will not be sufficient and it will be difficult to reach the qualified amount of finished sand.
-Adjust the rotor impeller speed until it reaches the ideal standard.
8. Normal running sound become louder in a sudden, has rumbling sound
A. Causes
-Problems with the bearings.
-Foundation bolts or some connection bolts loose.
-Wear parts are seriously worn.
B. Effects on bearings
The imbalance of the rotor, external vibration may lead to abnormal bearings; poor quality of bearings also cause sudden damage easily, resulting in abnormal running of rotor at high speed.
C. Solutions
-Check whether the bearings are intact, replace the worn out ones in time, use high quality bearings.
-Tighten and fasten all the bolts regularly to avoid the sand making machine vibration.
-Replace wearing parts in time, maintain the rotor in a dynamic balance state.
9. Incredible idling resistance
A. Causes
Material blockage inside the sealing cover on the bearing.
B. Effects on bearings
The impurities will increase the rotor’s rotational resistance, they also cause wear or damage to the sealing parts, easily lead to bearing creep, wear and other damage.
C. Solutions
Remove the blocked material from the sealing cover, and also check whether the corresponding device is blocked with material.
10. VSI Sand making machine with metal clashing sound inside
A. Causes
Lining plate, rotor is loosen, or other wear parts drop off
B. Effects on bearings
If the rotor bearing sleeve inside metal wear or loosening, it is easy to cause the metal shedding material bite into the bearing inside, resulting in wear temperature rise or lock-up. If the external metal shedding, suddenly causing the rotor to stop, it is likely to cause internal bearing abrasion, cage fracture or sudden ablation.
C. Solutions
The operator should keep a good habit of regular inspection and maintenance of equipment, also make relevant rules to avoid similar problems.
