| 摘要 |
<p>An oil delivery system 100, for use in an engine, comprises first and second oil supply lines 104, 106 with respective first and second oil pumps 101, 102. The second pump 102 is further arranged to selectively pump oil into the first supply line 104. The second pump 102 may draw oil from the first supply line 104 so that the oil pressure in the second supply line 106 is higher than that in the first supply line 104. The second line 106 may be connected to the first line 104 by a third line 108 having a pressure relief valve 109 which opens if the force exerted on the valve 109 by pressure in the second line 106 exceeds that exerted on the valve 109 by pressure in the first line 104 by a predetermined amount. A non-return valve 110 may prevent oil from the third line 108 reaching the first pump 101. The arrangement can deliver three pressure profiles using just two pumps. Oil may be supplied from the first pump 101 to the bearings 112 via a fourth supply line 111.</p> |
