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1. internal reason for cone crusher runaway failure
Because the speed of eccentric sleeve of cone crusher is very high, which is much faster than the rotation speed of the main shaft, it determines that the contact position between the main shaft and the cone sleeve will change. When the number of contact positions decreases, the force on the contact position will increase.
When the force on the contact position is greater than the strength of the oil film, the oil film will break and dry friction will occur. Low quality or low quantity of lubricating oil may also cause dry friction.
When the dry friction between the main shaft and the cone sleeve of the cone crusher causes the temperature of the contact position to rise, it will result in the expansion of the cone sleeve and other serious consequences. As the temperature value of eccentric sleeve is usually less than that of copper sleeve, and the wall is relatively thick, as far as the expansion coefficient is concerned, the steel is relatively small, so the expansion is relatively light and the overall impact is small, which means that when the expansion occurs, the expansion direction can only be inward.
The distance between the main shaft and the cone sleeve will be narrowed, which will further aggravate the problem of heating. The gluing between the main shaft and the cone sleeve will also deteriorate, the speed of the main shaft is faster and faster, which result in “runaway” breakdown. The clearance between the main shaft and the cone sleeve of the cone crusher should be set reasonably, not too large or too small.
2. External causes for cone crusher runaway breakdown
1) The inner wall quality of the cone sleeve is not up to the standard, which leads to the contact between the cone sleeve and the main shaft, damaging the oil film and causing the spindle speed out of control;
2) The clearance between the main shaft and the cone sleeve is not scientific. If the clearance is too large, it will lead to the impact between the cone sleeve and the main shaft. If the clearance is too small, the lubricating oil at the contact part is not enough, and it is impossible or difficult to form an oil film;
3) The spherical shape is seriously damaged or the quality of bowl tile is not up to standard;
4) There are problems in the cooling system of the engine block, which cannot release heat in time, resulting in thermal imbalance, oil temperature rising and oil film strength being weakened;
5) The excessive load of the cone sleeve causes the zinc pouring to fall off, thus reducing the clearance between the spindle and the sleeve, resulting in the phenomenon of "shaft holding";
6) The thrust disc is seriously worn due to long-term working;
7) When the cone crusher is installed, the clearance between the tooth tip and the tooth side is unreasonable.
If you are confused by the problems of cone crushers, or interested in our crushing machines, please contact Zenith engineers for help.