The installation of the crusher is one of the key points in the design of the mobile crushing station. A reasonable installation form can effectively suppress vibration transmission, reduce sound, and noise, and effectively improve the service life of electrical components and power units. A reasonable installation form is especially important to the service life and performance of the crusher.
The following is a brief analysis of several installation forms of the crusher and the comparison of their advantages and disadvantages.
1 Rigid connection
1.1 Connection method
As shown in Figure 1, the main crusher and the frame are connected by bolts and nuts, and there is no buffer and vibration reduction device between the main crusher and the frame. Because the bolt has a large elastic modulus and a small deformation, this solution is regarded as a rigid connection.
1.2 Anti-loosening of bolt spacer
The crusher needs to withstand a significant impact when it is running, and the occurrence of bolt loosening is related to the structural design of the mechanical equipment. Whether it can absorb or buffer the dynamic load directly determines the performance of the bolt. If the structural design cannot be optimized, steel spacers can be added to improve the bolt’s ability to resist impact. This solution is to increase the total elastic deformation by lengthening the bolts and use the deformation to offset the load impact to ensure the pre-tightening force and prevent the bolts from loosening. The application of spacer anti-loosening is shown in Figure 2.
1.3 Advantages and disadvantages
When rigidly connected, because there is no buffer and vibration reduction device between the crusher and the frame, the vibration generated by the crusher is directly transmitted to the frame, and there is almost no buffer and vibration suppression. Therefore, the joint of the frame and the crusher and the frame Other connected parts are subject to varying degrees of vibration damage, and their service life is affected to varying degrees. Therefore, this solution is not suitable for crushers with greater impact, such as jaw crushers and cone crushers. However, its advantages such as simple structure and low cost are particularly obvious. It is often used in impact crushers with little impact. At this time, attention should be paid to the local strengthening of the frame structure to prevent fatigue fracture of the frame.
2 Rubber damper connection
2.1 Connection method
Shock absorbers for crushers generally use “sandwich” rubber shock absorbers. The upper and lower two steel plates and the middle rubber block are glued together. The steel plate has threaded holes for bolt fastening, and the rubber block is used for vibration damping and energy absorption. As shown in Figure 3, the crusher is connected to the upper steel plate of the shock absorber by bolts, and the frame is connected to the lower steel plate of the shock absorber by bolts.
2.2 Limit radial displacement
Due to the small bonding force between rubber and steel plate, this type of shock absorber is only allowed to withstand axial pressure and small radial shear forces. The crusher will produce greater impact and vibration when it is working, so the crusher generally chooses a belt drive for buffering and energy absorption. In order to ensure that the drive belt has sufficient pre-tightening force, prevent the belt from derailing and flying out, and to avoid the shock absorber from being damaged by radial overload, the radial displacement of the shock absorber must be limited, so it is necessary to increase the pre-tightening force of the crusher drive belt The mechanical locking mechanism (as shown in Figure 4) uses a screw to limit the displacement of the crusher in this direction.
2.3 Advantages and disadvantages
Based on the rigid connection, the rubber shock absorber is added between the crushing main body and the frame, which can effectively reduce the impact and suppress the transmission of vibration. It is an effective and reliable method for damping vibration, sound insulation and noise reduction. Rubber shock absorbers are widely used, high in quality and low in price, and are developing in the direction of scale and standardization. The selection and matching are simpler, so it is also the most effective and mainstream solution at present. Due to the shortcomings of easy aging of rubber, the service life of rubber shock absorbers is about 5 years, and it is difficult to cover the entire life cycle of the equipment.
3 Rubber shock absorber + cylinder leveling
3.1 Connection method
As shown in Figure 5, the cylinder barrels of the oil cylinder 8 and the oil cylinder 9 are connected with the crusher, the piston rod of the oil cylinder is connected with the steel plate on the upper side of the shock absorber 3, and the steel plate on the lower side of the shock absorber 3 and the shock absorber 5 is connected with the frame 4. The upper steel plate of shock absorber 5 is connected to the crusher 1. The rodless cavity of oil cylinder 8 and the oil cylinder 9 are connected through the oil pipe 7, and the rodless cavity of the two oil cylinders is filled with butter through the butter filling port 6. The pressure in the rodless cavity is always equal.
3.2 Leveling and aligning
When the front and rear mounting surfaces of the frame or crusher (as shown in Figure 5a) are out of tolerance, the amount of butter can be increased or decreased through the butter filling port. The cylinder 1 and cylinder 2 have the same pressure in the rodless cavity and expand and contract to achieve the out-of-tolerance adjustment in the front and rear directions. When the left and right mounting surfaces of the frame or crusher (as shown in Figure 5b) are out of tolerance, the rodless cavity of cylinder 1 and cylinder 2 are connected, and the rodless cavity with high pressure will flow to the rodless cavity with low pressure to realize the rodless cavity of the left and right cylinders. The pressure is the same. Considering the low compressibility of butter, the respective expansion and contraction amounts of cylinder 1 and cylinder 2 remain unchanged. The adjusted crusher and cylinder can be regarded as a whole, and the system has 4 independent modules: crusher, frame, The shock absorber 1 and the shock absorber 2 have the same effect as the rubber damping scheme at this time.
3.3 Advantages and disadvantages
The frame of the mobile crushing station is a welded component, which is deformed under the influence of welding stress. It is difficult to guarantee the geometric tolerance of the mounting surface, even with the aid of welding tooling. Solve the assembly stress caused by structural tolerance. To meet the actual use requirements, the mainstream solutions of major manufacturers at present are to improve the technical requirements and strengthen the process control of the installation location. However, due to the prohibitive cost and poor stability, the effect is not ideal. However, the solution of “rubber shock absorber + cylinder leveling” can perfectly solve this problem. However, due to the addition of components such as oil cylinders and pipelines, the economy is poor.