Fan having a step diffuser

Patent metadata

Field	Value
Publication number	US-2025084867-A1
Application number	US-202218728205-A
Country	US
Kind code	A1
Filing date	Dec 22, 2022
Priority date	Jan 14, 2022
Publication date	Mar 13, 2025
Grant date	—

Abstract

A fan, in particular an axial or diagonal fan, comprising a housing and an impeller arranged therein and driven by an electric motor and having vanes extending between a hub ring and a cover ring, wherein a step diffuser is formed in the form of an abrupt expansion of the flow cross-section in the direction of flow downstream of the impeller and after exiting the region of the cover ring.

First claim

1 . A fan, comprising:
a housing; an impeller arranged in the housing and rotationally driven by an electric motor, with blades extending between a hub ring and a cover ring; and a step diffuser in the form of an abrupt expansion in a flow cross section formed downstream of the impeller and downstream of an outlet from a region of the cover ring in the flow direction.

2 . The fan as claimed in claim 1 , wherein a cross-sectional step of the step diffuser has a surface ratio >=110%.

3 . The fan as claimed in claim 1 , wherein an inner contour of the housing is approximately cylindrical.

4 . The fan as claimed in claim 1 , wherein a contour of the cover ring interacts with an inner contour of the housing in relation to a main flow and secondary flow, wherein an imaginary downstream extension of the contour of the cover ring does not intersect the inner contour of the housing.

5 . The fan as claimed in claim 4 , wherein the main flow flows through an inlet nozzle into the impeller and flows through the housing via inner and outer throughflow regions, and the secondary flow, as a partial flow of the air emerging from the impeller, flows back between the cover ring and the inner contour of the housing and enters the region of the impeller again via a radial gap between the inlet nozzle and the cover ring.

6 . The fan as claimed in claim 1 , wherein a supporting redirection device, which influences the flow in the region of the step diffuser, is arranged downstream of the impeller in the flow direction.

7 . The fan as claimed in claim 1 , wherein a supporting redirection device is integrally integrated on the housing and the housing is manufactured by plastics injection molding.

8 . The fan as claimed in claim 1 , wherein a supporting function for the motor and impeller is taken on by a suspension, made of steel or another metallic material.

9 . The fan as claimed in claim 1 , wherein the hub ring of the impeller has a large central opening toward a rotor of the motor for cooling purposes.

10 . The fan as claimed in claim 1 , wherein a ratio of an outlet diameter of the housing at its outflow-side edge to an inner outlet diameter of the cover ring of the impeller is greater than 1.05.

11 . The fan as claimed in claim 1 , wherein the cover ring of the impeller extends beyond a region approximately parallel to an impeller axis or with a small pitch angle with respect to the impeller axis, and wherein the hub ring of the impeller has a conical profile with a diameter increasing in the flow direction.

12 . The fan as claimed in claim 1 , wherein the cover ring, radially outward in the vicinity of the outflow-side edge, has a larger pitch angle with respect to the fan axis.

13 . The fan as claimed in claim 1 , wherein an outlet diameter of an inlet nozzle is at least slightly smaller than an outlet diameter at the cover ring of the impeller, and a ratio of outlet diameter from the housing to outlet diameter of the inlet nozzle of greater than 1.05.

14 . The fan as claimed in claim 1 , wherein openings are formed in the housing, the openings fluidically connecting a region associated with a secondary flow between an inlet nozzle or the cover ring of the impeller and the housing to a region outside the housing.

15 . The fan as claimed in claim 12 , wherein the angle is between 5° and 15°.

16 . The fan as claimed in claim 1 , wherein the fan is an axial or diagonal fan.

Assignees

• Ziehl Abegg Se

Inventors

• Loercher Frieder
• Gross Andreas

Classifications

• F04D29/326 Primary

  comprising a rotating shroud · CPC title

• F04D29/281

  for fans or blowers · CPC title

• F04D25/06

  the pump being electrically driven (F04D25/08 takes precedence) · CPC title

• F04D19/002

  Axial flow fans · CPC title

• F04D17/06

  Helico-centrifugal pumps · CPC title