An improved method to improve excavator rotary motor durability

A method to improve excavator rotary motor durability improvement - 2020 11 - 30 ShangFuLi zhang fei ( Xugong group mining machinery division) Hydraulic excavator rotary motor is its core parts and components of the hydraulic system, rotary motor under certain pressure and flow of hydraulic oil drive a steady torque and rotary motion, the input of the hydraulic oil pressure can be converted to rotary motion of mechanical energy, restore hydraulic excavator to achieve the upper fuselage movements. The small hydraulic excavator main current configuration axial piston rotary motor. 1. Rotary motor rotary motor structure is mainly composed of oil distribution plate, inclined plate, the stator, transmission shaft, cylinder and so on, the oil distribution disc and inclined plate fixed stator, drive shaft connected to the cylinder block and rotation of the rotor, shaft at both ends are equipped with needle roller bearing and taper roller bearing. Rotary motor structure and the principle as shown in figure 1. Rotary motor in friction pair for sports, namely the plunger piston and cylinder hole, cylinder block and oil distribution plate, slipper and swash plate. The pressure inside the rotary motor oil after this 3 of movement of the friction pair clearance leakage into the space between the cylinder and motor shell, then through the drain on the motor shell mouth flow directly back to the hydraulic oil tank, the drain Dr In figure 1 b. It can not only ensure the motor oil pressure in the body is zero, and may at any time to take away heat, cooling the hot oil in the rotary motor. Tapered roller bearing is located in the bottom of the rotary motor, and close to the rotary gear reducer, as with needle bearing, reducer and lever mechanism consisting of a fulcrum shaft 4, stress is very uniform, the leaking oil lubrication of the bearing under its own gravity, so generally will not damage. Needle roller bearing of rolling body is thin and long, radial structure is compact, particularly applicable to the limited size of the radial installation supporting parts, because this often is applied to the upper drive shaft. 2. The existing problems in the needle roller bearing at the top of the shaft, its only through the leakage of hydraulic oil lubrication. Because the region circulation of hydraulic oil quantity is very less, caused the poor lubrication bearing, its internal pollutants not discharge in time. Under the effects of the high temperature in high speed rotary motor rotation, dry friction between needle roller bearing and pollutants, aggravate the wear and tear. Needle roller bearing structure as shown in figure 2. In addition, due to the needle roller bearing is located in the upper drive shaft, and in its and tapered roller bearings, gear reducer and the shaft is composed of 4 leveraged institutions, equivalent to leverage the endpoint, so stress non-uniform, vulnerable to the drive shaft torque of single direction, the needle roller bearing fatigue wear under the condition of the poor lubrication. Due to poor lubrication needle roller bearing and the stress condition, cause its produce vibration and noise, shorten its service life, thereby adversely affecting the performance of rotary motor as a whole, eventually leading to a rotary motor failure. According to the statistical data analysis, rotary motor damage reasons of needle roller bearing, a third is fatigue wear, two-thirds to bad lubrication. Improve the former rotary motor structure is shown in figure 3. 3. Method we added on the rotary motor needle bearing oil mouth, and through the one-way valve connected to the hydraulic oil tank, one-way valve opening pressure is filling oil mouth back pressure, usually is 0. 5MPa。 Oil mouth is for rotary motor stops release pressure and eliminate air-pocket set oil mouth, to supply the rotary motor with hydraulic oil and release the pressure. In order to improve the needle roller bearing lubrication bad condition, we increased the orifice on the rotary motor shell, forming oil mouth - Orifice - The mouth of the oil return oil duct. Due to fill oil mouth has a certain pressure, so oil compensating mouth of hydraulic oil through the orifice to outlet, the formation of the hydraulic oil flow through the cycle of needle roller bearing, the needle roller bearing lubrication, cooling, which can reduce pollutants, enhance its lubrication, can reduce the fatigue wear and improve the service life. The improved rotary motor structure as shown in figure 4. 4. Improvement in accordance with the above method to improve the way of needle bearing lubrication lubrication, the market validation results show that the rotary motor durable performance got improved, related excavator not appear damage of needle roller bearing fault. In the journal of construction machinery and maintenance 12, 2017