Pump bearing retainer

Patent metadata

Field	Value
Publication number	US-12110901-B2
Application number	US-202117148778-A
Country	US
Kind code	B2
Filing date	Jan 14, 2021
Priority date	Jan 17, 2020
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

A wet-running pump bearing retainer (29) includes a radial bearing configured for a lubrication film between an inner sliding surface (41) and a rotor shaft (13) of a pump (1). The radial bearing is fitted into a radially inner section (49) that defines an axial fluid channel (45), located at a first radial distance (D1) to a rotor axis (R) and providing a fluid flow path (F1) in a first axial flow direction. The first radial distance is larger than a radius (D0) of the inner sliding surface. A radially outer section (51) extends from the inner section and defines a second axial fluid channel (47) for a flow path (F2) in a second axial flow direction, opposite to the first flow direction. The second axial fluid channel is located at a second radial distance (D2) to the rotor axis, which is larger than the first radial distance.

First claim

What is claimed is:

1. A pump bearing retainer for a wet-running pump with a rotor shaft, the pump bearing retainer comprising:
a radially inner section;
a radial bearing with an inner sliding surface configured to allow a lubrication film between the inner sliding surface and the rotor shaft of the pump, the radial bearing being fitted into the radially inner section; and
a radially outer section extending radially outward from the inner section, wherein:
the radially inner section defines at least one first axial fluid channel providing a first fluid flow path in a first axial flow direction;
the at least one first axial fluid channel is located at a first radial distance to a rotor axis;
the first radial distance is larger than the radius of the inner sliding surface;
the radially outer section defines at least one second axial fluid channel providing a fluid flow path in a second axial flow direction through the at least one second axial fluid channel;
the at least one second axial fluid channel is located at a second radial distance to the rotor axis;
the second radial distance is larger than the first radial distance;
the second axial flow direction is opposite to the first axial flow direction; and
the at least one second axial fluid channel is formed as an arc-shaped slot having an arc radius equal to the second radial distance.

2. The pump bearing retainer according to claim 1 , wherein:
the radially inner section comprises an inner section surface for a press-fit contact with an essentially cylinder-shaped radial outer surface of the radial bearing; and
a shape of the inner section surface defines the at least one first axial fluid channel that is located between the inner section and the radial bearing.

3. The pump bearing retainer according to claim 1 , wherein the radially outer section defines n≥2 second axial fluid channels distributed in an n-fold rotational symmetry.

4. The pump bearing retainer according to claim 1 , wherein the at least one first axial fluid channel is axially offset with respect to the at least one second axial fluid channel.

5. The pump bearing retainer according to claim 1 , wherein:
the at least one first axial fluid channel has a total cross-sectional area that is at least ten times larger than a cross-sectional area of the lubrication film; or
the at least one second axial fluid channel has a total cross-sectional area that is at least ten times larger than a cross-sectional area of the lubrication film; or
the at least one first axial fluid channel has a total cross-sectional area that is at least ten times larger than a cross-sectional area of the lubrication film and the at least one second axial fluid channel has a total cross-sectional area that is at least ten times larger than a cross-sectional area of the lubrication film.

6. The pump bearing retainer according to claim 1 , wherein the at least one first axial fluid channel has a total cross-sectional area that is larger than 0.5 square millimeters.

7. The pump bearing retainer according to claim 1 , wherein the at least one second axial fluid channel has a total cross-sectional area that is larger than 0.5 square millimeters.

8. The pump bearing retainer according to claim 1 , wherein a maximal radial extension of the at least one second axial fluid channel is below 300 microns.

9. The pump bearing retainer according to claim 1 , wherein:
the at least one first axial fluid channel comprises m number of fluid channels;
the at least one second axial fluid channel comprises n number of fluid channels; and
m>n.

10. The pump bearing retainer according to claim 1 , wherein each arc-shaped slot extends over 0.05 to 0.5 radians.

11. The pump bearing retainer according to claim 1 , wherein:
the inner section surface comprises at least one first portion and at least one second portion in a circumferential direction;
the at least one first portion has a first radius;
the at least one second portion has a second radius that is larger than the first radius, such that the at least first portion defines at least one contact portion for a press-fit with an essentially cylinder-shaped radial outer surface of the radial bearing and such that the at least one second portion defines the at least one first axial fluid channel located between the inner section and the radial bearing.

12. The pump bearing retainer according to claim 1 , wherein the radial bearing or the inner sliding surface comprise a ceramic.

13. The pump bearing retainer according to claim 1 , wherein the radially outer section defines at least another second axial fluid channel providing another fluid flow path in the second axial flow direction through the at least another second axial fluid channel, the at least another second axial fluid channel being formed as an another arc-shaped slot having an another arc radius equal to the second radial distance, the at least another second axial fluid channel being located at a spaced location from the at least one second axial fluid channel in a circumferential direction with respect to a longitudinal axis of the rotor shaft of the pump.

14. A wet-running centrifugal pump comprising:
a permanent-magnet synchronous motor;
a rotor shaft;
an impeller mounted to the rotor shaft; and
a pump bearing retainer comprising:
a radially inner section;
a radial bearing fitted into the radially inner section, the rotor shaft being arranged in the radial bearing with a clearance to an inner sliding surface of the radial bearing for establishing a lubrication film; and
a radially outer section extending radially outward from the inner section, wherein:
the radially inner section defines at least one first axial fluid channel providing a first fluid flow path in a first axial flow direction;
the at least one first axial fluid channel is located at a first radial distance to a rotor axis;
the first radial distance is larger than the radius of the inner sliding surface;
the radially outer section defines at least one second axial fluid channel providing a fluid flow path in a second axial flow direction through the at least one second axial fluid channel;
the at least one second axial fluid channel is located at a second radial distance to the rotor axis;
the second radial distance is larger than the first radial distance;
the second axial flow direction is opposite to the first axial flow direction; and
the at least one second axial fluid channel is formed as an arc-shaped slot having an arc radius equal to the second radial distance.

15. The pump according to claim 14 , wherein an axial distance of the impeller to the radially outer section of the pump bearing retainer, measured at an outer radius of the impeller is below 2.0 millimeters.

16. The pump according to claim 14 , wherein an outer radius of the impeller is smaller than the second radial distance of the at least one second axial fluid channel to the rotor axis.

17. The pump according to claim 14 , wherein:
the at least one first axial fluid channel has a total cross-sectional area that is at least ten times larger than a cross-sectional area of the lubrication film; or
the at least one second axial fluid channel has a total cross-sectional area that is at least ten times larger than a cross-sectional area of the lubrication film; or
the at least one first axial fluid channel has a total cross-sectional area that is at least ten times larger than a cross-sectional area of the lubrication film and the at least one second axial fluid channel has a total cross-sectional area that is at le

Assignees

• Grundfos Holding As

Inventors

• Gaba Gunnar

Classifications

• F04D29/586

  specially adapted for liquid pumps · CPC title

• F04D13/0646 Primary

  the hollow pump or motor shaft being the conduit for the working fluid · CPC title

• F04D29/061

  especially adapted for liquid pumps · CPC title

• F04D29/0473

  for radial pumps · CPC title

• F04D13/0633

  Details of the bearings · CPC title