NEWS

Today, we use an example to analyze the causes and preventive measures of the wear of the eccentric parts of the cone crusher.

Introduction

For the three cone crushers in the medium and fine crushing process, the cone bushes were seriously worn out in about 6 months, seriously affecting production. For this reason, three cone crushers were overhauled and the wear of eccentric parts was analyzed.

Wear condition

The upper port of the main shaft taper bush is obviously worn, and the lower port has a narrow strip of wear, with no contact at all in the middle;

The upper side of the tapered bush close to the thin side of the eccentric bushing is severely worn, and the side of the lower side close to the thick side of the eccentric bushing is severely worn;

The width of the spherical bearing inside the oil return groove is about 100mm, and a ring belt wears evenly;

The upper part of the thick side of the eccentric bushing is obviously worn, and a narrow strip is worn at the bottom;

The outer ring of the thrust plate wears heavily;

The large end of the large bevel gear is heavily worn, and gradually shrinks along the tooth top from the large end to the small end in the tooth height direction, approximately forming a triangular impression.

Wear Analysis

When the crusher is unloaded, the main shaft is pressed on the thin side of the eccentric bushing, and when it is loaded, it is pressed on the thick side of the eccentric bushing. The eccentric bushing is always pressed against the straight bushing with a thick edge no matter it is unloaded or loaded. In this way, the wear of the main shaft and the taper bushing should be relatively uniform from top to bottom, at least the upper side of the taper bushing near the thick side of the eccentric bushing should be more worn, and the thick side of the eccentric bushing should also be more worn. But judging from the actual situation of wear and tear, it is just the opposite.

The eccentric shaft sleeve is inclined to the side of the balance weight, as shown in the figure below. Because only in this way can the taper bush and the eccentric bushing be in contact with A, B, C and D respectively, which is consistent with the actual wear condition.

The wear of the spherical bearing shows that the supporting force of the spherical bearing will not exceed half of the central angle of the spherical surface, and the contact between the two is normal. It is also normal that the thrust plate wears heavily along the outer ring, because the outer ring speed of the thrust plate is high, so its wear is faster than the inner ring. In addition, for the heavy wear of the large bevel gear head, it is determined by the special motion state of the gear, which can also be regarded as a normal phenomenon.

Therefore, the main reason for the wear of eccentric parts is the deflection of the eccentric bushing, and the deflection of the eccentric bushing is caused by the improper maintenance and installation of the gasket, thrust plate, taper bushing and eccentric bushing. In this case, the crushing force cannot make the eccentric shaft sleeve reset normally, causing the eccentric shaft sleeve to deflect, resulting in wear of the eccentric parts, and in severe cases, local loads can cause cracks.

Precaution

1) Strictly adjust the clearance of the eccentric part according to the instruction manual. During actual maintenance, the bottom gap of the taper bushing can be increased, but the upper gap must be ensured.

2) During maintenance, ensure that the surface roughness and thickness of the upper, middle and lower thrust plates are uniform, and the installation of the thrust plates is shown in the figure.

3) When adjusting the clearance of the bevel gear, ensure that the thickness of the gasket added to the lower part of the thrust plate is uniform, and the edge of the gasket cannot be wrinkled during installation.

4) When installing the thrust plate, the round pin should be smoothly inserted into the pin hole to avoid skewing the eccentric bushing.

Shanvim as a global supplier of crusher wearing parts, we manufacture cone crusher wearing parts for different brands of crushers. We have more than 20 years of history in the field of CRUSHER WEAR PARTS. Since 2010, we have exported to America, Europe, Africa and other countries in the world.