Solution to the fracture of the cone crusher spindle

 The cone crusher is a crushing device commonly used in production. Spindle breaks are a common type of failure during production runs. Frequent breaks in the spindle not only affect normal production, but also aggravate routine maintenance and overhaul work. For this fault, this paper analyzes the cause of the fault and finds a solution. A detailed analysis of the causes of the main shaft fracture and the solutions are as follows.

First, the reason for the broken shaft
(1) The strength of the main shaft is weak: the static fit between the main shaft and the broken vertebral body causes stress concentration on the main shaft section, which significantly reduces the fatigue strength of the main shaft material. The main shaft gradually cracks during the crushing process of the crusher. The bending stress at the stress concentration of the spindle is broken beyond the strength of the material.
(2) Overload operation: Due to insufficient spring pressure, the upper support sleeve of the crusher often jumps when overloaded, resulting in excessive product size. Therefore, the operator often adopts the method of recompressing the safety spring to increase the crushing force, thereby increasing the force of the main shaft, so that the main shaft is subjected to excessive force.
(3) Frequent iron and iron: In order to obtain the qualified product size, the crushing workshop often reduces the number of shots, causing the number of times of crushing the chamber to pass iron or iron, which causes the bending stress in the dangerous section of the spindle to reach a certain value.

Second, the solution
For the above reasons, the analysis of the spring pressure is not enough. From the design considerations, the number of irons is increased due to the reduction of the discharge port. It can be solved by operation, that is, the iron check work is strengthened; if the fatigue strength is insufficient, the following measures can be taken to improve the resistance of the spindle. Fatigue strength:
(1) Increasing the load-reducing groove will reduce the press-fit; make a circle of load-reducing grooves at the lower edge of the body of the static pressure-bonding part between the main shaft and the broken cone body.
(2) Improve the rounded shape of the broken shaft part, and roll the static pressure part of the main shaft to increase the surface finish and surface hardness.
(3) Reduce the interference of the static pressure of the main shaft and reduce the interference between the main shaft and the cone body. In order to ensure that the spindle and the body do not loose during operation, a certain amount of interference is required. The *er the interference, the stronger the stress concentration, but the more the stress concentration decreases, the more severe the fatigue strength of the spindle is reduced.
(4) Increase the transition angle between the main shaft fitting portion and the cone to reduce the stress concentration factor.
(5) According to the newly designed spring pressure, the shaft of the shaft is designed correspondingly, and the diameter of the shaft is generally increased.