摘要 |
A hydraulic system, suitably an ink supply system for an ink jet printer, wherein a first pump conveys ink under pressure from a reservoir to a work head and a gear pump returns unused liquid from a collector at the work head to the reservoir. A bleed line connects an outlet from the first pump to an inlet to the gear pump. Accordingly, there is a flow of liquid via the bleed line such that the gear pump applies sufficient suction to the collector to draw air or a mixture of air and unused liquid therefrom. The flow is also sufficient to ensure adequate lubrication of the gear pump. The first pump may also be a gear pump, in which case the two pumps are formed as a double-ended pump. |