Patent ID: 9222476
Filing Date: 2015-12-29
Classification: F04D

Abstract:
1. A rotary pump comprising: a pump housing comprising a circumferential inner wall enclosing a flow space, the pump housing provided with an intake opening and a discharge opening that is connected to the circumferential wall, wherein the intake opening and the discharge opening are connected to each other by the flow space; an impeller wheel disposed in the flow space and configured to be driven in rotation; an expansion body fluidically connected to the flow space; a spiral casing embodied separate from the pump housing, the spiral casing mounted inside the flow space of the pump housing and surrounding an outer circumference of the impeller wheel; wherein the spiral casing comprises a circumferentially extending wall comprising a first circumferential end and a second circumferential end opposite the first circumferential end, wherein the circumferential wall has a circumferential length measured from the first circumferential end to the second circumferential end, wherein the spiral casing is configured such that a free cross-section of a flow passage, defined between the outer circumference of the impeller wheel and an inwardly facing surface of the circumferentially extending wall of the spiral casing, increases continuously in the circumferential direction across said circumferential length in a conveying direction toward the discharge opening, wherein the spiral casing is a single-part or multi-part shaped component.