Troubleshooting methods for the BW219D-2 type roller without strong vibration

During the operation of a BW219D-2 type roller, the strong vibration of the front steel wheel suddenly disappeared, leaving only slight vibration.

This type of roller is driven by a hydraulic pump to drive the vibration motor, and then the excitation motor drives the eccentric block on the excitation shaft, thereby causing the steel wheel to vibrate. The rotational speed of the motor controls the strong vibration and the slight vibration of the roller, that is, it controls the magnitude of the amplitude. The two excitation shafts of the steel wheel are connected together through a coupling in the middle and drive the eccentric block to rotate together, thereby causing vibration.

During operation, when the vibration switch is turned on, the vibration solenoid valve opens the supply oil passage of the hydraulic pump, and the vibration drive motor starts to work. The excitation motor is connected to the excitation shaft through a spline rubber sleeve. The excitation shaft on the left drives the excitation shaft on the right to rotate together, generating vibration.

Based on the analysis of the fault phenomenon, it is believed that there may be the following two situations.

1. There is a malfunction in the hydraulic system

As shown in the attached figure, if solenoid valve 7 or 4 is damaged, the vibration motor will not generate vibration. Now there is a slight vibration, indicating that the solenoid valve is not faulty. Furthermore, if the springs of safety valves 5 and 6 are damaged, it may also lead to low oil supply pressure without strong vibration. However, we measured that the pressure of the safety valve 6 of the vibration pump is 44MPa, which is normal. The pressure of the safety valve 5 of the vibration motor is 42 MPa, which is also normal. Therefore, the possibility of a fault in the hydraulic system can be ruled out.

2 There is a fault with the excitation shaft inside the steel wheel

When the left side of the steel wheel was opened for observation, it was found that the rubber block of the coupling had broken and the right excitation shaft was broken.

The reason for this is as follows: Due to the breakage of the coupling rubber block, the two excitation shafts have been subjected to mechanical shock for a long time. Without the buffer rubber block, the excitation shafts are bound to break because they cannot withstand the long-term fatigue shock.

When dealing with such faults, it is necessary to start from reality. If imported shafts are used instead, it will take a long time and cost a lot. Therefore, domestic parts are considered as substitutes.

During disassembly and installation, it should be noted that 1.9L of silicone oil should be added to the eccentric block during disassembly. The eccentric block is in a tight fit with the excitation shaft. It is best not to open the eccentric block during disassembly because the silicone oil will leak if it is opened, and the sealing ring for sealing the silicone oil is not easy to purchase. Therefore, it is best to remove the eccentric block as a whole. Also, since there is oil in it, it is not suitable for heating. It is not easy to remove it with impact force. It is best to press it down with a press and make a mark. During the installation process, the eccentric block can also be pressed onto the excitation shaft with a press, and attention must be paid to the installation direction. After replacing the coupling rubber block, it can be assembled and used.