| 摘要 |
PURPOSE:To reduce the thrust force by forming a hollow path passing inside the shaft from the end section of a driving shaft to the front section of oil seal fitted along the driving shaft to prevent oil leakage so as to balance the liquid pressures applied to both side faces of the driving gear. CONSTITUTION:The liquid leaking through the gap between the side face of a driving gear 34 and a side plate 44 flow from the high pressure side (discharge path 48) to the low pressure side (suction path 46) and also reach the front face of an oil seal 54 through a hollow section 62 provided inside the driving shaft 34, and further return to the suction path 46 through a guide port 60. Accordingly, the liquid pressure in the hollow section 62 is made almost equal to the pressure in the suction path 46, and the cross section area of the side face of the driving gear 34 in the hollow section 62 is made equal to that of a driving shaft 32, therefore the liquid pressures applied to both side faces of the driving gear 34 are almost balance, thus generating no thrust force. Thereby, the thrust force applied to the driving gear 34 can be suppressed with small number of parts being used. |
