Besides The Lining Plate Itself, What Problems Can Be Indirectly Caused by Poor Contact of The Dynamic Cone Support Surface Or Wear of The Spherical Bearing Shell?

The cone crusher is a precision dynamic system, in which the moving cone is supported on the frame through spherical bearings and completes complex pendulum movements under the drive of an eccentric sleeve. When the contact between the supporting surface of the moving cone is poor or the spherical bearing is worn, seemingly unrelated to the lining plate, it can indirectly cause a series of damages to the lining plate by changing the motion trajectory and force state of the moving cone. This article is based on the principles of equipment dynamics and on-site fault cases, systematically analyzing the indirect effects of these hidden factors on the lining plate.

1、 Function and working status of the dynamic cone support system

The moving cone is the core moving component of the cone crusher, with its bottom supported on the spherical bearing shell of the spherical bearing seat. During operation, it performs both slow rotational motion and lateral stroke motion with the eccentric sleeve. The function of spherical bearing is to bear the self weight and crushing force of the moving cone, and allow the moving cone to swing freely within a certain range.

In an ideal state, the dynamic cone forms a good surface contact with the spherical bearing, and the crushing force is evenly transmitted to the frame through the spherical bearing. But when the contact between the supporting surface is poor or the spherical bearing is worn, the motion trajectory of the moving cone changes, and the transmission path of the crushing force is changed. This change will indirectly affect the moving cone liner and the fixed cone liner.

2、 The indirect impact of poor contact on the supporting surface on the lining plate

1. Causing uneven distribution of load on the lining plate

When the contact between the moving cone and the spherical bearing is poor, the support state of the moving cone changes. According to on-site fault analysis, uneven force on the moving cone can cause excessive equipment vibration, which is directly transmitted to the surface of the lining plate.

Under normal operating conditions, the lining plate bears a relatively uniform crushing force along the circumferential direction. But when the contact between the supporting surface of the moving cone is poor, the moving cone will produce additional deflection and shaking during the rotation process, resulting in periodic changes in the gap between the moving cone liner and the fixed cone liner. The side with a smaller gap bears excessive crushing force, while the side with a larger gap receives insufficient force. This biased load state causes stress concentration in the local area of the lining plate, accelerating the wear process in that area.

2. Increased risk of liner loosening

The increased vibration of the dynamic cone caused by poor contact of the supporting surface will subject the locking system of the fixed lining plate to additional impact loads. When the vibration frequency is close to the natural frequency of the equipment, the locking bolt may loosen and the compression ring weld may experience fatigue cracking. Once the lining plate begins to loosen, it will further intensify wear during subsequent crushing operations, forming a vicious cycle.

3. Causing local overload and rupture of the lining plate

During the operation of the crusher, if the contact between the supporting surface of the moving cone is poor, the moving cone may experience instantaneous instability. At this point, the crushing force that should have been evenly borne by the spherical bearing will directly act on certain local areas of the lining plate through the moving cone. When the local load exceeds the strength limit of the lining plate, cracks may appear on the surface of the lining plate, and in severe cases, the lining plate may rupture and fail.

3、 The indirect effect of spherical bearing wear on lining plate

1. Move the cone downwards to change the shape of the crushing chamber

Spherical bearings are wear-resistant components, and the alloy layer will gradually wear out after long-term operation. Research has shown that the wear of spherical tiles gradually develops from the outer ring to the inner ring. When the spherical bearing wears down, the moving cone will move downwards, and the relative position between the moving cone liner and the fixed cone liner will change accordingly.

The case of a standard cone crusher with a diameter of 2200 in a certain mine shows that after a period of grinding, the contact surface between the moving cone and the spherical bearing is worn, and the alloy layer is worn. The downward movement of the moving cone causes the gap between the cone liner and the cone shaft to decrease, ultimately leading to heating and deformation of the liner. The downward movement of the moving cone directly changes the geometric shape of the crushing chamber, causing the originally designed laminated crushing state to be destroyed, and the wear rate of different areas of the lining plate to change.

2. Instability of the dynamic cone causes abnormal impact on the lining plate

When the spherical bearing wears out to a later stage, there may be a situation where the inner ring contacts, which is equivalent to the spherical bearing becoming smaller, and the supporting reaction force of the spherical bearing exceeds that of the spherical bearing, causing the dynamic cone to become unstable. The direct manifestation of dynamic cone instability is that the main shaft may get stuck at the lower mouth of the cone liner, causing cracks and damage to the lower mouth of the cone liner.

More seriously, after severe wear of the spherical bearing shell, the dynamic cone may lose stable support, resulting in violent oscillation or even "flying cone" phenomenon during the crushing process. This abnormal movement causes abnormal rigid contact between the moving cone liner and the fixed cone liner, generating impact forces far exceeding the design load, which can easily lead to liner rupture.

3. Wear of spherical tiles leads to deterioration of the force state of the cone

The wear of spherical bearing shells can also change the overall force state of the moving cone. Under normal operating conditions, the forces borne by the dynamic cone include the inertia force of the cone, self gravity, reaction force of the spherical bearing, and reaction force of the eccentric shaft sleeve, which are in a relatively balanced state. When the spherical bearing wears out, the direction and point of action of the reaction force of the spherical bearing change, and the original force balance is disrupted.

A case study of a certain mine pointed out that the deviation of the eccentric shaft sleeve can cause the crushing force to fail to reset the eccentric shaft sleeve normally, resulting in continuous deviation of the eccentric shaft sleeve and wear of the eccentric components. This skewed state changes the crushing force borne by the dynamic cone liner from a multi-directional balanced force to a unidirectional local force, exacerbating the risk of local wear and rupture of the liner.

4. Increased vibration accelerates lining fatigue

After the wear of the spherical bearing, the smoothness of the dynamic cone operation decreases and the equipment vibration significantly increases. Vibration not only affects the crushing effect, but also causes the lining plate to bear additional alternating loads. Under continuous vibration, the fatigue process of the lining material accelerates, and micro cracks are easily generated on the surface and gradually propagate.

Research has shown that when the spherical tile is severely worn, it may cause the lining on the moving cone to be severely worn by the spherical tile, resulting in copper chips falling off the inner wall of the lining on the moving cone and blocking the oil passage of the spherical tile, causing strong vibration during the operation of the crusher. This vibration will be directly transmitted to the lining plate through the moving cone, accelerating the fatigue peeling of the lining plate.

4、 Summary of the transmission pathways of indirect damage

To clearly present the indirect impact path of support system faults on the lining plate, the following table summarizes the main fault transmission mechanisms:

Typical manifestations of indirect effects of direct consequences of fault types on lining plates

Poor contact on the support surface, uneven force distribution on the dynamic cone, uneven load distribution on the lining plate, accelerated and eccentric wear in local areas

The vibration of the dynamic cone intensifies the loosening of the lining plate locking system, and the lining plate becomes loose and displaced

Instantaneous instability of the dynamic cone, local overload cracking and rupture of the lining plate

Abnormal wear pattern of spherical bearing shell due to the downward movement of the cone and the change in the shape of the crushing chamber caused by wear

Unstable lining plate of dynamic cone subjected to abnormal impact, crack and rupture

Deterioration of stress state, single directional concentration of crushing force, severe local wear

Equipment vibration intensifies, lining plate fatigue accelerates, fatigue peeling occurs, and service life is shortened

5、 Preventive measures and maintenance recommendations

1. Regularly check the condition of spherical bearings

A regular inspection system for spherical bearings should be established. When wear is found on the outer ring of the spherical tile, the inspection frequency should be increased to assess the degree of wear in a timely manner. The inspection includes the wear amount, contact area, surface quality, etc. of the spherical tile.

2. Monitoring equipment operating parameters

By monitoring the vibration values, current fluctuations, hydraulic pressure and other operating parameters of the crusher, the working status of the support system can be indirectly determined. Abnormal fluctuations in parameters are often a precursor signal to support system failures.

3. Standardized installation and maintenance

During the maintenance process, it is necessary to ensure the installation quality of spherical bearings and ensure that the surface roughness and thickness of the upper, middle, and lower thrust discs are uniform. When installing the thrust disc, ensure that the round pin is smoothly inserted into the pin hole to avoid causing the eccentric shaft sleeve to tilt.

4. Timely repair or replace worn parts

When the wear of the spherical bearing shell reaches the specified limit, it should be repaired or replaced in a timely manner. Continuing to use severely worn spherical bearing shells not only accelerates the damage of the lining plate, but may also cause more serious equipment accidents, such as flying cones, spindle fractures, etc.

5. Optimize feeding and iron removal management

Good feeding management and effective iron removal measures can reduce fluctuations in crushing force and abnormal impacts, and alleviate the additional burden on support systems and lining plates. Uniform feeding and no iron passing are the basic conditions for ensuring the long-term stable operation of the support system.