Abstract
Temperature of bearing and seal parts in the rotating cylinder-block type and rotating swash-plate type axial piston pumps was measured. For the rotating cylinder-block type, five thermo-couples were embedded in the swashplate; For the rotating swash-plate type pump, five thermo-couples were installed in the cylinder-block and one was at the casing. A hydraulic mineral oil with ISO VG 46 was used as the test oil. The maximum discharge pressure was 20 MPa, maximum discharge flow rate was 16 l/min, and the inlet oil temperature was specified at 30℃. From the atmospheric to maximum discharge pressures, the temperatures, flow rates and the torque were measured. In conclusion, i) For the rotating cylinder-block type, the swash-plate temperature at the trapping part between the suction port and discharge port was highest; ii) For the rotating swash-plate type, the cylinder-block temperature about the cylinder-bores at the block end, corresponding to the bottom dead center of the pistons, was highest, and iii) As the discharge pressure and/or the rotating speed increased, the temperatures raised.
