斜板式アキシァルピストンポンプの熱潤滑特性（斜板ならびにシリンダブロックの温度測定）

摘要

流体の圧力エネルギーを利用したフルードパワーrn（油圧）システムにおいては，システムの要となるポrnンプ・モータの信頼性向上や小型高圧化に対する要請rnが強い．さらに，環境負荷の低減も含めて，長寿命やrn高効率化への対応が急務とされている．%Temperature of bearing/seal parts of axial piston pumps was measured. Both of a rotating cylinder-block type pump and a rotating swash-plate type pump were prepared; five thermo-couples were embedded in the swash-plate and one thermistor was placed in the suction conduit for the former pump, and five thermo-couples were installed in the cylinder-block and one was at the casing for the latter pump. Hydraulic mineral oils with ISO VG22, 32, 46 and 68 and the waterglycol type hydraulic fluid with VG32 were used at the test fluids. The maximum discharge pressure was 20 MPa and the maximum rotational speed was 28.3 rps. The inlet oil temperature was specified at 30 to 50°C. At the atmospheric pressure to the maximum discharge pressure, the temperatures, flow rates and the torque were measured. In conclusion, ⅰ ) The temperature of the swash-plate between the crescent-shaped discharge and suction ports increased greatly; ⅱ) The temperature of the cylinder-block at the bottom dead center of the pistons increased markedly; ⅲ) The temperature increased as the discharge pressure and the rotational speed became higher; ⅳ) The temperature rise was larger as the fluid viscosity was higher and the inlet oil temperature was lower, and ⅴ) The temperature rise in the case of the water-glycol fluid was noticeably smaller than the rise of the mineral oils.