To provide a plunger pump for feeding liquid capable of preventing air from mixing in feeding liquid.
A channel part 36 is provided along the peripheral direction on an inner peripheral face of a packing 28. A communicating pipe 34 communicating with a storage part 30 is stored in the channel part 36. A plurality of small holes are provided in the communicating pipe 34. The small holes are plugged by an outer peripheral face of a plunger rod 12. When a clearance occurs between the plunger rod 12 and the packing 28, liquid in the storage part 30 flows out into the clearance through the small holes in the communicating pipe 34. For this reason, if the plunger rod 12 is worn, and amount of liquid in the storage part 30 is reduced. That is, a wear condition of the plunger rod 12 is informed by the amount of liquid in the storage part 30 to prevent air bubbles from being mixed in feeding liquid by replacing the plunger rod 12 before air is mixed in a flow passage 40.
Kato Kazunori
Katsuichi Nishimoto
Hiroshi Fukuda