Detailed Analysis of Faults in the Vibration System of Road Rollers

The vibration system is the main working system of the vibratory roller. The roller completes construction tasks through this system. Therefore, analyzing and eliminating faults in the vibration system is of great significance for improving work efficiency and extending the service life of the machine.

The common faults in the vibration system mainly include: the vibration wheel does not vibrate, the vibration of the vibration wheel is intermittent, and the vibration wheel makes abnormal noises. The reasons can be analyzed from three aspects: the electrical system, the hydraulic system and the vibrating wheel.

Electrical system

Under normal circumstances, if the quality of the vibration switch itself is problematic or the operating force is insufficient, it will lead to poor contact of the vibration switch. Therefore, if the vibrating wheel does not vibrate, one should first check whether the vibrating switch is in good condition and whether the contact is good. Otherwise, it should be repaired or replaced. Secondly, check whether there are any phenomena such as damaged relays, blown fuses, short circuits or open circuits in the electrical circuits (with a focus on the circuit from the vibration switch to the control solenoid valve of the vibration pump). If any are found, they should be eliminated.

2. Hydraulic system

When the flow and pressure of the hydraulic pump of some oil engines fail to reach the set values, it is necessary to check whether the throttle control lever is in the correct position, or have the diesel engine repaired by professionals to bring it to the normal speed.

(2) Severe wear of hydraulic pumps and hydraulic motors: The dimensional accuracy, processing technology and quality of hydraulic components do not meet technical requirements, leading to early wear. Mechanical wear and other impurities in the hydraulic system cause early wear of the three pairs of friction pairs, namely the plunger and plunger hole, the sliding shoes and swash plate, and the distribution plate and the end face of the cylinder block, leading to internal leakage. To address this issue, an external circulation filtration device should be used to thoroughly remove the mechanical wear and impurities from the hydraulic system. After inspecting the pump or motor, maintenance personnel often forget to add oil to the casing, causing the friction pair to operate without lubrication. This leads to severe wear of the pump and motor within a short period of time, resulting in internal leakage. This feature reminds all maintenance personnel to pay attention to adding oil to the casing to avoid unnecessary losses.

(3) If hydraulic accessories such as valves and pipe joints malfunction, for instance, if the vibration switch valve is damaged, the swash plate will not be able to deflect. That is, the displacement of the vibration pump will be zero, the motor will not rotate, and the vibration wheel will not vibrate either. A damaged pressure shut-off valve will cause it to open prematurely, resulting in pressure relief in the swash plate control circuit and the swash plate returning to zero. This will cause the system pressure to fail to meet the requirements, leading to excessive hydraulic oil pressure in the vibration system. As a result, the vibration motor will not rotate or its rotational speed will be too low, resulting in no vibration or weak vibration. If the relief valve is damaged, it will open prematurely to overflow and relieve pressure, causing the system pressure to fail to reach the set value. In the vibration system, due to excessive hydraulic oil pressure, the vibration motor will not rotate or the rotational speed will be too low, and the vibration wheel will not vibrate or vibrate very weakly. During this meal, the O-ring at the joint was damaged, resulting in poor sealing and breakage. If the quick-change coupling is not tightened properly, preventing the oil from conducting through, etc., it may cause the vibrating wheel to not vibrate or vibrate very weakly. When components such as hydraulic valves malfunction, professional personnel should be invited for repair. If necessary, damaged parts should be replaced to ensure the normal operation of the equipment. If the filtration accuracy of the hydraulic oil filter is relatively low or the filter is damaged, the hydraulic system should be cleaned and replaced with clean hydraulic oil and a high-precision filter.

3. Vibrating wheel

Most faults in the vibration system occur in the mechanical part. The following parts are the most prone to failure.

(1) The splined shaft connecting the vibration motor and the eccentric device was first broken. This situation is extremely rare and usually occurs on new machines. It is mainly caused by severe deviations in coaxiality and perpendicularity between the components of the vibrating wheel, or by the breakage or loosening of the fixing bolts at the parts of the vibrating wheel. The second issue is the severe wear of the nylon sleeve. If there are problems with the material or strength of the nylon sleeve of the coupling, or if the coaxiality of the eccentric device is seriously out of tolerance, it can lead to premature damage of the nylon sleeve, causing faults such as no vibration, weak vibration or intermittent vibration in the vibration system.

(2) The lubrication, heat dissipation and clearance conditions of vibrating bearings will directly affect the service life of the bearings. If the bearings are poorly lubricated, severe wear will occur in an extremely short time, accompanied by noise. Early damage to vibrating bearings is often caused by the quality problems of the shaft itself and improper assembly. If the wear resistance, hardness, dimensional accuracy and manufacturing process of the bearing do not meet the requirements; The assembly was not carried out in accordance with the procedures, and the bearings were prone to damage during assembly. The axial clearance of the bearing is too small, etc. Therefore, the clearance during the installation of the bearing must comply with its specified requirements. Compared with ordinary high-speed and heavy-load bearings, the performance requirements for vibration bearings are higher. If bearings not provided by the main machine manufacturer are rashly selected, vibration failure will occur. Therefore, when users choose vibration shafts, they must select brands and specifications that are provided by the manufacturer or recognized by after-sales personnel to avoid losing the big picture for small gains and causing serious consequences.

(3) Amplitude modulation device: The existing vibratory rollers generally adopt a dual-frequency and dual-amplitude structure that is adjustable. If the amplitude modulation device of the vibrating wheel is damaged, a loud impact sound will be generated during vibration operations. During the process of starting or stopping the vibration, a clear and continuous impact sound can be heard. During vibration, there will be symptoms such as disordered amplitude, intermittent vibration, and sometimes large and sometimes small. At this time, The damaged parts must be replaced.