| 摘要 |
The invention relates to a plunger pump for conveying a liquid medium, in particular water, comprising a pump housing (1) with at least one cylinder (2) and at least one plunger (20) that is guided in said cylinder and can be moved along the cylinder axis (4) by means of a drive (17). To prevent medium that has been leaked in the drive-side end (16) of the cylinder (2) as a result of the travel play of the plunger (20) from mixing with the lubricant used for the drive elements of the pump, said pump is equipped with a drainage unit (6). This comprises a first sleeve (30), which is coaxial with the cylinder (2), is connected to the plunger foot (24) on the drive-side end (21) of the plunger (20) and can thus be moved along with the plunger (20). The first sleeve also at least partially surrounds the exterior of the outer cylinder (11) and has a conical drainage surface (31) extending radially outwards. The drainage unit also comprises a second sleeve (40), which is coaxial with the cylinder (2) and is connected to the pump housing (1), in addition to a run-off channel (41) that is orientated radially inwards. Preferably, both sleeves (30, 40) overlap one another in a labyrinthine manner, but do not make contact with one another. By the consistent exploitation of the dynamic conditions prevailing during operation, the leaked medium is conveyed to the run-off channel (41) via the first and second sleeve and is thus fed in a fail-safe manner to the run-off unit (44). This permits a reliable, contactless and thus wear-free operation. |
