Technical renovation of hydraulic motors

Thread Content

According to Li Gong from Yilan, who specializes in hydraulic equipment, the imported VV140 single-roller vibratory roller of Slovakian origin faces a shortage in spare parts. As the manufacturer continues to improve the product and update its hydraulic components, damage to any of these components can prevent the roller from functioning properly. Therefore, it was decided to modify the front-drive hydraulic motor. 1. Necessity of modification: The single-wheel drive motor uses French internal-curve low-speed high-torque motors; due to inadequate maintenance, the plunger, cylinder body, and internal-curve track disc of these motors suffer from severe wear. The internal leakage of the front drive motor increases, resulting in insufficient driving force and weak movement; it cannot be repaired, and the roller cannot operate. Therefore, it must be replaced. It is an early model of the original Motor series; the prices of its components are relatively high, resulting in high costs for purchasing parts and for repairs, as well as long lead times for acquiring these parts. Taking into account factors such as cost-effectiveness and usability, it was decided to improve this hydraulic system. 2. Modification method: The machine was originally driven by a low-speed hydraulic motor; it can be modified to use a high-speed motor paired with a reducer, ensuring that the total torque and speed remain roughly consistent. The displacement of the original engine’s motor is 4–6 L/r. Speed matching: The reduction gear has a speed ratio of 107∶1, and the motor’s displacement is 0.056 L/r. Therefore, the total displacement at the same rotational speed is: 107×0.056=5.992 L/r (after reduction), which is basically the same. The torque of the original drive motor is as follows: when the pressure P=10 MPa, the torque is 9,557 N·m; when the pressure P=35 MPa, the total torque = 9,557×10^7 N·m = 33,449.5 N·m. The motor model used for the modification is A2FM56; at a pressure of P=35 MPa, its torque is 312 N·m, and the total torque is 312×107=33,384 N·m. It can be seen that it is comparable to the original motor torque. The appearance and installation dimensions of the modified motor and reducer are relatively similar to those of the original motor; the relative distance between their mounting plates is larger, and this issue can be resolved by adjusting the size of the arc-shaped plate on the original machine. The installation conditions before and after the renovation are shown in the attached drawings. After the modification, the front drive motor became a high-speed motor, which works well in combination with the reducer. No problems have been detected after using it for over half a year; the system pressure and oil temperature are normal.