Pump housing with dual-purpose inlet fitting

A pump housing for an eccentric screw pump, the housing comprising:

• a casing extending along a housing axis,
• a connecting shaft in the casing,
• a shaft seal at an upstream end of the casing and surrounding the connecting shaft,
• a stator mounted at a downstream end of the casing, and
• a tubular inlet fitting for the housing, projecting transversely from the housing axis for supplying a medium to be conveyed, the shape of the inlet fitting being such that a flow of medium into the housing through the inlet fitting is in an inflow direction that has a flow component directed radially outward from the housing axis and a flow component directed axially toward the upstream end, the inlet fitting having an inner wall shaped to form a spiral flow passage.

An eccentric screw pump comprising:

• a pump casing extending along an axis and having an upstream end and a downstream end,
• a stator connected to the downstream end,
• a rotor in the stator,
• a coupling rod in the pump casing,
• a drive having a shaft connected to the coupling rod,
• a shaft seal provided on the pump casing at the upstream end for sealing around the shaft, and
• an inlet fitting opening into the casing adjacent the shaft seal so that medium flows into the casing through the fitting and then around the shaft seal with a component of flow directed radially outward from the axis and a component of flow directed axially toward the upstream end, an inner cross-sectional area of the inlet fitting tapering at least partially toward the casing such that an output cross-sectional area of the inlet fitting is smaller than an inlet cross-sectional area thereof and/or is asymmetrically offset.

An eccentric screw pump comprising:

• a pump casing extending along an axis and having an upstream end and a downstream end,
• a stator connected to the downstream end,
• a rotor in the stator,
• a coupling rod in the pump casing,
• a drive having a shaft connected to the coupling rod,
• a shaft seal provided on the pump casing and at upstream end for sealing around the shaft, and
• an inlet fitting opening into the casing adjacent the shaft seal so that medium flows into the casing through the fitting and then around the shaft seal with a component of flow directed radially outward from the axis and a component of flow directed axially toward the upstream end, the inlet fitting having an inner wall shaped to form a spiral flow passage.