3047 Thermal Lubrication Characteristics of Rotating Cylinder-block Type and Rotating Swash-plate Type Axial Piston Pumps
Details
Temperature of tribological parts of axial piston pumps with a mechanism of a rotating cylinder-block or a rotating swash-plate was measured. For the rotating cylinder-block type pump, five thermo-couples were embedded in the swash-plate and one thermistor was placed in the suction conduit. For the rotating swash-plate type pump, five thermo-couples were installed in the cylinder-block and one was at the casing. Hydraulic mineral oils with ISO VG68, VG46, VG32 and VG22 and a water-glycol type oil with VG32 were used as the test oil. The maximum discharge pressure was 20MPa, and the inlet oil temperature was specified at 20-40℃. At the atmospheric to maximum discharge pressures, the temperatures, flow rates and the torque were measured. In conclusion, i) The temperature of the swash-plate between the discharge and suction ports increased markedly; ii) The temperature of the cylinder-block at the bottom dead center of the pistons rose greatly; iii) The temperature rise was increased as the oil viscosity was higher, and iv) The temperature rise in the case of the water-glycol type oil was smaller than the rises of the mineral oils.
