orbit motor It is a kind of low speed and high torque multi-purpose Hydraulic motor It is widely used in mechanical equipment. Cycloidal motor, with plane flow distribution structure, displacement q=245mL/r, pressure=15.5MPac

The motor suffered from output fatigue during operation. After disassembly and inspection, it was found that there were three obvious signs of heptagonal wavy scratches on the front cover surface and the fixed port plate end surface in contact with the motor stator and rotor end surface.

The causes of scratches and repair methods are briefly described as follows.

1. The scratch condition and the damage to the system The scratch condition on the front cover surface is relatively light, the scratch depth is shallow, and the shape is in the shape of heptagonal wavy lines (see Figure 1); The end face of the fixed port plate is severely scratched, with a scratch depth of 0.1~0.2mm and a width of 0.1~0.3mm, and the shape is also in the shape of heptagonal wavy lines (see Figure 2).

Since the front end cover surface and port plate contacting with the stator and rotor end surface will be scratched, the seven enclosed oil cavities of the motor will be interconnected, resulting in severe internal leakage of the motor, which will seriously affect the motor output torque. In operation, it is reflected in the motor running fatigue.

2. Causes of scratches

The object of operation of this equipment is concrete gravel. The operating environment is very unfavorable, and the lack of necessary ash prevention methods promotes the heavy pollution of hydraulic oil, resulting in damage and scratch of motor end face movement pair, which is also the key reason:

The cycloidal motor is a combined structure, and is composed of a front end cover, a stator ring (the rotor is in the stator ring), a fixed port plate, a rear end cover, etc. The gap between the front end cover and the fixed port plate is very small

When the motor is running, the rotor rotates in the stator ring and forms a layer of lubricating oil film with the contact surface on both sides. When sundries enter the middle of the two contact surfaces, they destroy the lubricating oil film, resulting in direct friction of the motion pair and many fine wear debris; Second, if there are hard debris particles squeezed between the rotor teeth and the end faces on both sides and operated together with the rotor, it will lead to regular damage and scratches as shown in Figure 1 and Figure 2.

3. Repair method

The scratch on the end face of the front end cover is relatively slight, which can be repaired by grinding, that is, brushing red lead powder on the grinding platform, using 600 # grinding sand as wear-resistant material, grinding continuously, finally grinding off the scratch on the surface layer, and ensuring that the surface layer has a guaranteed surface roughness.

4. Methods for inhibiting damage and scratch

Change the oil in the hydraulic system and remove the sundries, particles and wastes left in the system; Set the high-precision oil filter again; Assemble ash prevention equipment for the oil tank to prevent sundries from entering the oil tank; Strengthen protective measures, maintain regularly and change oil.