| 摘要 |
<p>PURPOSE:To reduce the cost of equipment and lengthen the lifetime of bearings of a fixed-volume hydraulic pump and a variable-volume hydraulic pump, by using these pumps together. CONSTITUTION:An electricity generator 9 is driven by a main engine 1 through the fixed-volume hydraulic pump 6, the variable-volume hydraulic pump 7 and a hydraulic motor 8. When the rotational frequency of the main engine 1 is at a rated level, the fixed-volume hydraulic pump 6 supplies such a quantity of oil that the electricity generator 9 could produce electricity of frequency slightly lower than a prescribed level. At that time, the shortage of oil is compensated by the variable- volume hydraulic pump 7. When the rotational frequency of the main engine 1 falls and the discharge of the fixed-volume hydraulic pump 6 decreases, the discharge of the variable-volume hydraulic pump 7 is increased. The frequency of electricity produced by the generator 9 is thus maintained at the prescribed level. This construction enables decreasing the volume of the variable-volume hydraulic pump 7 to a half, reducing the cost of equipment and lengthening the lifetime of the bearings.</p> |
