Search

EP-4737730-A1 - MICRO-AXIAL PUMP WITH PRESS-FIT IMPELLER

EP4737730A1EP 4737730 A1EP4737730 A1EP 4737730A1EP-4737730-A1

Abstract

An axial pump for delivering liquid coolant to cool an electronic device comprises a conduit, an impeller in the conduit, a shaft, a rotor, and a motor stator. The conduit defines a flow path from an inlet of the conduit to an outlet of the conduit. The rotor is disposed in a hollow interior of the impeller and comprises magnetic portions, a front bearing housing, and a rear bearing housing. The front and rear bearing housing comprising bearings rotatably coupling the rotor to the shaft. The motor stator is configured to drive rotation of the rotor about the shaft, with the impeller rotating along with the rotor about an axis of rotation extending parallel to the flow path. The rotor is coupled to the impeller by a press-fit attachment of the front bearing housing to the impeller.

Inventors

  • LESTER, Laura
  • KUFAHL, Benjamin John
  • LUNSMAN, HARVEY JOHN

Assignees

  • Hewlett Packard Enterprise Development LP

Dates

Publication Date
20260506
Application Date
20250409

Claims (15)

  1. An axial pump for delivering liquid coolant to cool an electronic device, comprising: a conduit defining a flow path from an inlet of the conduit to an outlet of the conduit; an impeller in the conduit; a shaft disposed in and coupled to the conduit; a rotor disposed in a hollow interior of the impeller, the rotor comprising magnetic portions, a front bearing housing, and a rear bearing housing, the front and rear bearing housing comprising bearings rotatably coupling the rotor to the shaft, the rotor being coupled to the impeller by a press-fit attachment of the front bearing housing to the impeller; a motor stator configured to drive rotation of the rotor about the shaft, the impeller rotating with the rotor about an axis of rotation extending parallel to the flow path.
  2. The axial pump of claim 1, wherein the front bearing housing comprises knurls protruding from an outer surface of the front bearing housing.
  3. The axial pump of claim 2, wherein the knurls are arranged in two or more layers stacked axially along the outer surface of the front bearing housing, optionally: wherein each of the layers comprises multiple of the knurls distributed evenly around a perimeter of the front bearing housing; and/or: wherein each of the layers comprises six of the knurls; and/or wherein the knurls have a barbed configuration.
  4. The axial pump of claim 2 or 3, wherein the impeller comprises an engagement portion configured to engage with the front bearing housing, the engagement portion including a bore having an inner bore diameter; and wherein the knurls include a pair of knurls disposed diametrically opposite one another and a diameter of the front bearing housing at the pair of knurls exceeds the inner bore diameter of the bore of the engagement portion.
  5. The axial pump of claim 4, wherein the front bearing housing includes intermediate portions between adjacent ones of the knurls, and a diameter of the front engagement portion between a pair of the intermediate portions diametrically opposite one another equal to or less than the inner bore diameter of the bore of the engagement portion.
  6. The axial pump of any one of the preceding claims, wherein the rotor comprises a bearing tower comprising the front bearing housing, the rear bearing housing, and a bearing tower shaft extending between the front bearing housing and the rear bearing housing, the shaft of the pump extending through the bearing tower shaft, the magnet portions coupled to the bearing tower and distributed around the bearing tower shaft.
  7. The axial pump of any one of the preceding claims, wherein the bearings include a front radial bearing disposed in the front bearing housing, a rear radial bearing disposed in the rear bearing housing, and a rear thrust bearing disposed in the rear bearing housing; and/or wherein the rotor is mechanically coupled to the impeller by the press-fit attachment without any bonding agents or adhesives affixing the rotor to the impeller; and/or wherein the impeller comprises an impeller body and one or more blades protruding radially from and spiraling axially and circumferentially along the impeller body.
  8. An electronic device, comprising: a printed circuit board (PCB); an electrical component coupled to the PCB; a chassis housing the PCB; a cold plate thermally coupled to the electrical component; and the axial pump of any one of the preceding claims disposed within the chassis, wherein the conduit of the axial pump is fluidically coupled with the cold plate.
  9. The electronic device of claim 8, wherein the electronic device is a server and the electrical component is a processor.
  10. A system, comprising: a plurality of information processing devices, each comprising a chassis, a printed circuit board disposed in the chassis, an electrical component coupled to the PCB; and a cold plate thermally coupled to the electrical component; a plurality of instances of the axial pump of any one of claims 1 to 7, wherein each of the axial pumps is disposed in the chassis of one of the information processing devices the conduit of the respective axial pump is fluidically coupled with the cold plate of the respective information processing device; a liquid cooling loop comprising liquid coolant supply lines configured to supply liquid coolant to the axial pumps, liquid coolant return lines configured to return liquid coolant from the pumps, and a heat exchanger configured to cool the liquid coolant.
  11. The system of claim 10, comprising: wherein the axial pumps are individually controllable to individually adjust the flow rate of the liquid coolant through the information processing devices.
  12. A method of manufacturing an axial pump, comprising: providing a rotor comprising the rotor comprising magnetic portions, a front bearing housing, and a rear bearing housing, the front and rear bearing housing comprising bearings to rotatably couple the rotor to a shaft; inserting the rotor into a hollow interior of an impeller; and press-fitting the front bearing housing into an engagement portion of the impeller by pressing the rotor and the impeller together using press-fitting equipment.
  13. The method of claim 12, wherein the rotor is mechanically attached to the impeller by the press-fitting without the use of bonding agents or adhesives bonding the rotor to the impeller.
  14. The method of claim 12 or 13, further comprising coupling the rotor to the shaft prior to inserting the rotor into a hollow interior of an impeller.
  15. The method of claim 14, comprising: inserting an assembly of the impeller, the rotor, and the shaft into an impeller chamber; inserting a first end of a shaft of the impeller into a hub of a first support coupled to the impeller chamber; coupling a second end of the shaft to a second support coupled to the impeller chamber; positioning a first stator subassembly on a first lateral side of the impeller chamber and a second stator subassembly on a second lateral side of the impeller chamber, the first and second stator subassemblies comprising two portions of a motor stator configured to drive rotation of the impeller; assembling the first and second stator subassemblies and the impeller chamber by moving the first and second stator subassemblies towards the impeller chamber such that the impeller chamber is captured between the first and second stator subassemblies; and coupling a pump inlet structure to one end of the impeller chamber and coupling an pump outlet structure to an opposite end of the impeller chamber, the pump inlet structure, pump outlet structure, and impeller chamber forming a conduit defining a flow path of the axial pump.

Description

INTRODUCTION Some information processing systems utilize liquid cooling techniques to remove heat from the system. In these systems, a liquid coolant is circulated in a loop through the information processing devices (e.g., servers, networking devices, etc.) of the system, and heat generating components thereof (e.g., processors) are thermally coupled (e.g., via cold plates) to the liquid coolant so that the liquid coolant absorbs heat from these components. As the now-heated coolant exits the information processing devices, it carries the heat to a cooling device (such as a heat exchanger) which cools the liquid back to a desired operating temperature, whereupon the cooled liquid is circulated through the loop once again, extracting more heat from the information processing devices. Such a liquid cooling loop uses one or more pumps to drive the circulation of the liquid through the loop. Often, these pumps are disposed in a so-called coolant distribution unit (CDU) which provides a centralized pumping unit which circulates the liquid collectively through multiple information processing devices (e.g., an entire rack, or multiple racks, of such devices). These pumps are usually very large, with the CDU often taking up a substantial portion of a rack, or in some cases a full rack. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure can be understood from the following detailed description, either alone or together with the accompanying drawings. The drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate one or more examples of the present teachings and together with the description explain certain principles and operations. In the drawings: FIG. 1 is a schematic diagram illustrating a top view of an example pump.FIG. 2 is a perspective view of another example pump.FIG. 3 is an exploded view of the pump of FIG. 2.FIG. 4 is an exploded perspective view of an impeller chamber subassembly of the pump of FIG. 2, including a perspective sectional view of a portion of the impeller chamber subassembly with the section taken along the plane 4-4in FIG. 2.FIG. 5 is an exploded perspective view of a rotor and shaft of the pump of FIG. 2.FIG. 6 is a partially exploded perspective view of the rotor and shaft of FIG. 5 in a partially assembled state.FIG. 7 is a perspective view of the rotor and shaft of FIG. 5 in an assembled state.FIG. 8 is a front view of a front bearing housing of a rotor of the pump of FIG. 2.FIG. 9 is a front perspective view of the front bearing housing of FIG. 8.FIG. 10 is a rear perspective view of the front bearing housing of FIG. 8.FIG. 11 is a rear perspective view of a rear bearing housing of a rotor of the pump of FIG. 2.FIG. 12 is a rear perspective view of the rear bearing housing of FIG. 11 with a rear radial bearing installed.FIG. 13 is a rear perspective view of the rear bearing housing of FIG. 11 with a rear thrust bearing installed.FIG. 14 is a rear perspective view of the rear bearing housing of FIG. 11 with a retainer installed.FIG. 15 is a perspective cross-section of the impeller/rotor subassembly of the pump of FIG. 2 in a partially assembled state, with the section taken along the plane 4-4 indicated in FIG. 2.FIG. 16 is a cross-section of the impeller/rotor subassembly of the pump of FIG. 2 in an assembled state, with the section taken along the plane 4-4 indicated in FIG. 2.FIG. 17 is a cross-section of the pump of FIG. 2, with the section taken along theFIG. 18 is a schematic diagram of an information processing system with a pump. DETAILED DESCRIPTION In some cases, it may be desired to utilize relatively small pumps in liquid cooling loops, rather than the commonly used large CDU pumps. One advantage of using smaller pumps for liquid cooling information processing systems is that the smaller pumps can be more efficient than the larger pumps, in terms of the amount of liquid they can move per unit of energy spent. The smaller pumps can also fit in places that the large pumps will not, which opens opportunities for system designers to arrange their systems in new and potentially more efficient ways which would not have otherwise been possible. For example, smaller pumps can allow for a distributed pumping architecture to be utilized, in which each information processing device is provided with one or more small pumps localized to the device (e.g., disposed within, or adjacent to, the chassis of the device) to control the circulation of fluid locally through that device in an individualized manner, rather than using a single large centralized pumping unit to control the flow of fluid collectively through the devices. This distributed approach can improve efficiency and performance of the liquid cooling loop, potentially reducing power usage and noise while also delivering more coolant flow (and hence better cooling). In addition, this may also facilitate g