Axial flow pump with adjustable impeller

Abstract

An axial flow pump with an adjustable impeller is provided. An example axial flow pump for conveying liquid coolant to cool electronic devices includes a conduit and an impeller within the conduit, the conduit defining a flow path from the inlet to the outlet of the conduit. The impeller is rotatable about an axis of rotation parallel to the flow path. The pump also has a motor stator configured to drive the impeller body to rotate about the axis of rotation. Additionally, the pump includes an adjustment mechanism that couples the impeller to the conduit. The adjustment mechanism is actuable to translate the impeller relative to the conduit. This allows adjustment of the clearance between the blade tips of the impeller blades and the wall of the conduit.

Description

Technical Field

[0001] This disclosure relates to an axial flow pump and an electronic device. Background Technology

[0002] introduction

[0003] Electronic devices such as computers, network devices, and power supply units generate heat during use. Cooling systems can remove this heat from the components of these devices to keep them within desired operating temperatures. For example, liquid cooling technology can remove heat from the system using a flow of liquid coolant. In liquid cooling technology, liquid coolant from a liquid coolant circuit is configured to come into thermal contact with the heat-generating components of the electronic device via one or more heat-generating devices (such as cold plates) fluidly connected to the liquid cooling circuit. For example, in a computing system, a cold plate may be connected to the system's processor or other heat-generating components. The liquid coolant flows through the circuit, and as it passes through the heat-generating devices, heat from the heat-generating components is absorbed by the liquid coolant, thus cooling the components. When the now-heated coolant leaves the heat-generating devices, it carries away heat and eventually flows through cooling devices configured to remove heat from it, such as heat exchangers, radiators, and coolers. After being cooled, the liquid coolant can then return to one or more heat-generating devices to circulate through the circuit again. One or more pumps may be installed within such a liquid cooling circuit to allow the liquid coolant to flow through it. Summary of the Invention

[0004] According to one aspect of this disclosure, there is a axial flow pump for delivering a liquid coolant to cool an electronic device, the axial flow pump comprising: a conduit defining a flow path from an inlet to an outlet of the conduit, wherein the conduit includes a wall defining a chamber housing the impeller; an impeller located in the conduit, the impeller including: a shaft extending parallel to the flow path; an impeller body rotatably coupled to the shaft, wherein the impeller body is rotatable relative to the shaft and the conduit about a rotation axis parallel to the flow path; one or more blades coupled to the impeller body; a motor stator configured to drive the impeller body to rotate about the rotation axis; and an adjustment mechanism coupling the shaft to the conduit, wherein the adjustment mechanism is actuable to translate the shaft of the impeller and the impeller body relative to the conduit, wherein actuation of the adjustment mechanism causes a change in the gap between the blade tip of one or more of the blades and the wall of the impeller chamber.

[0005] According to another aspect of this disclosure, an electronic device is disclosed, comprising: a printed circuit board (PCB); an electrical component coupled to the PCB; a base frame housing the PCB; a cold plate thermally coupled to the electrical component; and an axial flow pump as described in a first aspect of this disclosure, the axial flow pump being disposed within the base frame, wherein a conduit of the axial flow pump is fluidly connected to the cold plate. Attached Figure Description

[0006] Alone or with Figure 1 This disclosure will be understood from the following detailed description. The accompanying drawings, which include figures and diagrams, are provided to provide a further understanding of this disclosure and are incorporated in and form a part of this specification. The drawings illustrate one or more non-limiting aspects and embodiments of the teachings herein and, together with the description, explain certain principles and operations. In the drawings:

[0007] Figure 1 It is a schematic diagram showing a top view of the pump.

[0008] Figure 2A It includes Figure 1 An enlarged schematic diagram of the area marked 2 shows the pump in its first state.

[0009] Figure 2B It includes Figure 1 An enlarged schematic diagram of the area marked 2 shows the pump in its second state.

[0010] Figure 3 This is a flowchart illustrating the process of tuning a pump.

[0011] Figure 4 This is a 3D view of another pump.

[0012] Figure 5 yes Figure 4 An exploded view of the pump.

[0013] Figure 6 yes Figure 4 An exploded perspective view of the pump impeller assembly, including a perspective cross-sectional view of a portion of the impeller assembly, wherein the cross-section is along... Figure 4 It is cut off from the plane 10-10.

[0014] Figure 7 yes Figure 4 A 3D view of the pump impeller.

[0015] Figure 8 yes Figure 4 A three-dimensional view of the impeller and the rear part of the impeller chamber of the pump.

[0016] Figure 9 yes Figure 8 A three-dimensional cross-sectional view of the impeller and the rear part of the impeller chamber, wherein the cross-section is along... Figure 8 It is cut off from plane 9-9 in the middle.

[0017] Figure 10 It is the second pump edge Figure 4 The cross section taken from plane 10-10 in the middle.

[0018] Figure 11 yes Figure 10 An enlarged view of region 11 in the image.

[0019] Figure 12 yes Figure 10 An enlarged view of region 12 in the image.

[0020] Figure 13 yes Figure 4 A three-dimensional cross-sectional view of the pump, where the cross-section is along... Figure 4 It is cut off from the plane 10-10.

[0021] Figure 14 It is a three-dimensional schematic diagram of the system and its electronic components, including the pump.

[0022] Figure 15 This is a flowchart illustrating the process of tuning a pump. Detailed Implementation

[0023] In some cases, it may be desirable to use a relatively small pump in a liquid cooling circuit. For example, in some situations, it may be desirable to place a smaller pump within an individual computing device or other relatively small electronic device (e.g., compared to a relatively large pump typically located outside the computing system to drive flow through multiple devices). Such a small pump can improve the efficiency and performance of the liquid cooling circuit, potentially reducing power consumption and noise, while also delivering more coolant flow (and thus achieving better cooling). Additionally, placing the smaller pump locally on the device it cools can also facilitate greater modularity and scalability of the system, as the system's pumping capacity naturally scales with cooling demands, since each new device added to the system comes with its own pump.

[0024] To allow pumps to be used locally in the devices they pump liquid coolant for cooling, pumps typically need to be quite small, especially when it is desirable to house the pump in a relatively limited space. For example, some enterprise computing systems, such as high-performance computer systems, are particularly dense and often have very little internal free space. Accordingly, pumps used with these systems may need to be quite small. Several smaller pumps have been developed, such as the micro axial flow pump described in U.S. Patent No. 11015608B2, the contents of which are incorporated herein by reference in their entirety. An axial flow pump has an impeller (a component that moves in the liquid to drive the flow) that rotates along an axis coaxial with the direction of liquid flow, unlike a centrifugal pump, whose impeller rotates along an axis transverse to the direction of liquid flow. The micro axial flow pump described in US11015608B2 allows for a relatively large reduction in pump size without compromising effectiveness or efficiency.

[0025] However, the small size and other configurations of such miniature axial flow pumps can present a variety of technical challenges. In particular, the performance of a miniature axial flow pump is largely dependent on the tip clearance between the blades of the rotating impeller and the surrounding walls of the impeller chamber; generally, the farther the tip is from the surrounding walls, the worse the performance. While tip clearance also affects the performance of other pumps and fans, this effect is more pronounced for miniature axial flow pumps. Specifically, the small size of the pump means that a given variation in the dimensions of the impeller and / or impeller chamber (e.g., due to manufacturing tolerances) can have a disproportionate effect on a miniature axial flow pump compared to a larger pump. For example, for a conventional pump with an impeller of 50 mm radius, a 0.5 mm variation in tip clearance might be equivalent to a 1% variation in impeller radius, while for a miniature axial flow pump with an impeller radius of, for example, 10 mm, the same 0.5 mm variation would be equivalent to a 5% variation in impeller radius. Furthermore, the impeller chamber in a miniature axial flow pump design can include a sloping transition zone between the chamber inlet and the central portion, and this sloping wall can make the tip clearance have an even greater impact on pump performance. Therefore, the tip clearance may have a greater impact on miniature axial flow pumps than it has on other pumps or fans before.

[0026] While a relatively small tip clearance is important for performance, it is also crucial that the blade tips do not contact the surrounding walls of the chamber, as this can degrade performance and potentially damage the pump. Therefore, if the nominal tip clearance is too small, some impeller tips may contact the surrounding walls due to manufacturing variations in the parts. Consequently, impeller design may need to account for a variety of manufacturing tolerances that can affect the tip clearance, and the nominal tip clearance may need to exceed the sum of these tolerances. In miniature axial flow pumps, many combinations (overlays) of tolerances determine the minimum nominal tolerance expected to prevent blade tips from contacting the chamber walls. These tolerances include bearing tolerances, machining tolerances of machined parts, injection-molded part tolerances (including draft angles required by the mold), component assembly tolerances, and suction tolerances of the plastic parts used in the pump. Due to all these overlapping tolerances, the minimum tip clearance that can be safely designed may be too large to achieve optimal pump performance. In other words, the designed tip clearance cannot be set to an optimal value without the potential risk of blade tips striking the chamber walls. While reducing manufacturing tolerances through the use of more precise manufacturing techniques may help reduce at least some of these tolerances, cost considerations may make such techniques impractical. Furthermore, even the most precise techniques may still leave too large a tolerance, preventing the desired tip clearance from being achieved.

[0027] Therefore, to address at least some of the aforementioned problems (among others), aspects of this disclosure envision a miniature axial flow pump with an impeller that can be adjusted to change the tip clearance between the impeller blades and the wall of the impeller chamber in which the impeller is disposed. More specifically, the position of the impeller is axially adjustable; that is, the impeller can be configured to translate along its axis of rotation, and this translation allows for a change in the tip clearance. In the miniature axial flow pump, the impeller has a transition zone, the wall of which, as described above, is inclined relative to the axis of rotation of the impeller, so that axial translation of the impeller can change the clearance between the blades and the inclined wall. When the impeller is axially translated in one direction (e.g., toward the inlet), the leading tips of the blades will be closer to the inclined chamber wall and the tip clearance will decrease, and when the impeller is axially translated in the opposite direction (e.g., toward the outlet), the blade tips will be further away from the inclined chamber wall and the tip clearance will increase. Therefore, even if the initial tip clearance after manufacturing is less than the desired performance, the tip clearance selected to achieve the desired pump performance can be obtained by adjusting the position of the impeller. This allows the impeller to be designed with a relatively ample nominal tip clearance, which reduces manufacturing costs while still allowing for the adjustment of the tip clearance to achieve the desired performance level after manufacturing. Therefore, better pump performance can be achieved while maintaining low manufacturing costs and also avoiding the risk of blade tip impact.

[0028] Turning now to the accompanying drawings, various apparatuses, systems, and methods according to non-limiting aspects of this disclosure will be described.

[0029] Figures 1 to 2B The diagram is a schematic representation of pump 100. Figure 1 Including schematic top view, Figure 2A and Figure 2B Including in different states Figure 1 A magnified view of the area marked 2. It should be understood that... Figures 1 to 2B It is not intended to illustrate a specific shape, size or other structural detail accurately or to scale, and embodiments of pump 100 may have different numbers and arrangements of the illustrated components, and may also include other components not shown.

[0030] like Figures 1 to 2B As shown, pump 100 includes a housing 110, a motor stator 120 (also referred to as "stator 120"), one or more electrical components 125, a conduit 130 defining a liquid flow path 101, and an impeller 140. The housing 110 and conduit 130 are shown in dashed lines as transparent to allow the other components to be seen. A portion of shaft 143 is... Figure 1 The part is also shown in dashed lines to indicate that it will be hidden in this view by the impeller 140. The components of the pump 100 will be described in more detail below.

[0031] Housing 110 includes one or more walls or other support structures that support and at least partially enclose or house some other components of pump 100. Housing 110 may be a single component or assembled from multiple components. In some examples, components of housing 110 may also be integral parts of other components of pump 100 and / or forming other components of the pump. For example, portions of conduit 130 may also form components of housing 110.

[0032] The motor stator 120 is configured to receive power from the PCA 150 and, in response, generate alternating magnetic fields that interact with the impeller 140 to rotate the impeller 140 about its axis of rotation 149. The motor stator 120 may include wire windings or other conductive materials to generate the magnetic field and / or a magnetically sensitive material, thereby transmitting and distributing the generated magnetic field in a desired pattern around the impeller 140. In some examples, the motor stator 120 includes two parts: a first stator portion 120a and a second stator portion 120b, such as... Figure 1 As shown. These portions 120a and 120b are arranged on opposite lateral sides of the conduit 130. US11015608B2 describes an example stator divided into two portions, and these stators can be used, for example, as a motor stator 120. Those skilled in the art are familiar with motor stators that can be used as motor stators 120.

[0033] Pump 100 may also include one or more electrical components 125 for controlling the operation of pump 100. In some examples, electrical component 125 includes control circuitry configured with logic to drive the operation of pump 100. For example, the control circuitry may include a microcontroller. As another example, attached to or replacing a microcontroller, the control circuitry may include discrete logic circuitry (digital or analog). Electrical component 125 may also include sensors, such as temperature sensors, power usage sensors, humidity sensors (e.g., for leak detection), magnetic field (e.g., Hall effect) sensors, or other sensors. Electrical component 125 may also include power transmission components, such as transistors or other switches (e.g., relays), capacitors, diodes, etc. In some examples, electrical component 125 may include communication components for communicating with external devices, such as system controllers, baseboard management controllers (BMCs), rack controllers, etc., via cables (not shown) connected to pump 100 and / or wirelessly (e.g., via Bluetooth, WiFi, etc.). Electrical component 125 may be electrically connected to motor stator 120 to provide electrical signals to the motor stator, thereby driving the operation of motor stator 120. Electrical component 125 can be connected to an external power source via a wire or cable (not shown).

[0034] The conduit 130 includes walls that enclose a volume and define a liquid flow path 101 within that volume, wherein the liquid flow path 101 is the path along which a liquid coolant (e.g., water or other coolant) flows through the pump 100. The conduit 130 includes a pump inlet portion 131 (also referred to as “inlet 131”), a pump outlet portion 132 (also referred to as “outlet 132”), and an impeller chamber portion 133. The impeller chamber portion 133 houses an impeller 140 and is fluidly coupled to the inlet 131 and the outlet 132. The pump inlet portion 131 and the pump outlet portion 132 may include structures for fluidly coupling the pump to a coolant line in a liquid cooling circuit, such as hose barbs, quick-connect fittings, and / or other liquid coupling mechanisms familiar to those skilled in the art. In addition to the openings in the inlet 131 and the outlet 132, the conduit 130 may be liquid-tight, thereby sealing the internal volume from the external environment, while these openings allow the enclosed internal volume to be fluidly coupled to the external environment (e.g., to a coolant line in a liquid cooling circuit). In some examples, inlet 131 and outlet 132 may extend outside the housing 110 of pump 100. In some examples, impeller chamber portion 133 is housed within housing 110.

[0035] In some examples, impeller chamber 133 includes an impeller chamber inlet portion 134 (also referred to as "inlet portion 134") coupled to pump inlet portion 131, an impeller chamber center portion 136 (also referred to as "center portion 136"), and a transition region 135 between impeller chamber inlet portion 134 and impeller chamber center portion 136. In some examples, impeller chamber 133 includes an impeller chamber outlet portion (unlabeled) coupled to pump outlet portion 132, and a second transition region (unlabeled) between impeller chamber outlet portion and impeller chamber center portion.

[0036] The conduit 130 has a central longitudinal axis 139, and the liquid flowing through the conduit 130 flows entirely in a direction parallel to the central longitudinal axis 139, such as... Figure 1 The dashed arrow indicating flow path 101 indicates that (part of the liquid may occasionally flow at an angle relative to axis 139 along a portion of conduit 130, such as when the liquid is moving around impeller 140, but the bulk or average movement of the liquid as a whole through conduit 130 is in a direction parallel to axis 139). In some examples, the liquid is only present in pump 100 after pump 100 has been deployed for a liquid cooling circuit (e.g., connected to coolant supply and return lines), and is not present in other states (e.g., the state of pump 100 at the time of manufacture).

[0037] Impeller 140 is housed within conduit 130, specifically within its impeller chamber 133, and is configured to rotate about an axis of rotation 149 to drive liquid along flow path 101 through conduit 130. The axis of rotation 149 of impeller 140 may also be a central longitudinal axis of impeller 140, and these axes may also be aligned with the central axis 139 of conduit 130. Impeller 140 includes an impeller body 145 and blades 141 that project radially from impeller body 145 and spiral axially along the impeller body. Blades 141 are configured to propel liquid axially through conduit 130 along flow path 101 as impeller 140 rotates. Figure 2A and Figure 2BAs shown, impeller blades 141 include blade tips 142, which include, for example, the portion of blade 141 furthest radially from the axis of rotation 149 and also furthest axially from the outlet 132. Impeller 140 can be configured to rotate in response to a magnetic field generated by motor stator 120. For example, impeller 140 may include permanent magnets and / or magnetically attractive (e.g., ferromagnetic) materials (e.g., iron, steel, etc.) (not shown) arranged around impeller 140 to interact with the magnetic field generated by motor stator 120, thereby causing impeller 140 to rotate. Thus, impeller 140 and motor stator 120 can together form an electromagnetic motor, wherein impeller 140 acts as the rotor portion of the motor. In some examples, impeller 140 may include a tapered profile at one or both ends. In particular, in some examples, the radius of impeller 140 may be relatively small near impeller chamber inlet portion 134, gradually increasing throughout transition region 135, and reaching a maximum within impeller chamber central portion 136.

[0038] like Figure 1 As shown, the impeller 140 also includes a shaft 143, to which the impeller body 145 is connected, allowing the impeller body 145 to rotate about the shaft 143, but subject to other restrictions preventing any other relative movement between the impeller body 145 and the shaft 143 (i.e., apart from the impeller body 145 rotating about the shaft 143, the shaft 143 and the impeller 140 are stationary relative to each other). For example, in some embodiments, the impeller body 145 may be connected to the shaft 143 via bearings (not shown) such as axial bearings (e.g., ball bearings, thrust bearings, etc.) to allow the impeller body 145 to rotate relative to the shaft 143; and thrust bearings to prevent translation of the impeller body 145 relative to the shaft 143. The shaft 143 is mounted to the impeller chamber 133 via a front support 144 connected to and engaging and holding the front portion of the shaft 143, and a rear support 151 connected to and engaging and holding the rear portion of the shaft 143. In this article, relative to Figure 1 The orientation of the illustrated pump 100 uses "front" and "rear," with the inlet side being the "front" side and the outlet side being the "rear" side. However, these terms are intended only to aid understanding and not to limit. In particular, in some examples of the pump 100, the orientations of supports 144 and 151 may be reversed, with support 144 closer to outlet 143 and support 151 closer to inlet 131. In such cases, the terms "front" and "rear" as used herein will be reversed with respect to these components.

[0039] The impeller 140 further includes an adjustment mechanism 148. The adjustment mechanism 148 connects the shaft 143 to the rear support 151. The adjustment mechanism 148 is actuable and, when actuated, changes the position of the shaft 143 relative to the rear support 151, and therefore also changes its position relative to the impeller chamber 133. More specifically, the adjustment mechanism 148 is configured to translate the shaft 143 relative to the rear support 151 and the impeller chamber 133 along the axis of rotation 149. Since the shaft 143 is rigid and the front support 144 is connected to the impeller chamber 133, the translation of the shaft 143 relative to the impeller chamber 133 also includes the translation of the front end of the shaft 143 relative to the front support 144.

[0040] For example, the adjusting mechanism 148 may include a locating screw (or similar device, such as a bolt, threaded rod, etc.) coupled to the shaft 143 and an internal thread coupled to the rear support 151, such that when the locating screw is rotated, this causes the locating screw to translate, and thus also causes the shaft 143 coupled to the locating screw to translate. The internal thread may be integrally formed in the rear support 151 or may be part of a separate component such as a threaded sleeve or nut coupled to the rear support 151. In these examples, rotation of the screw may correspond to the aforementioned actuation of the adjusting mechanism 148.

[0041] In other examples, the adjusting mechanism 148 includes a frictional or interference fit between the shaft 143 and the rear support 151 to allow translation of the shaft 143 when sufficient thrust is applied, but to prevent translation of the shaft 143 under normal operating forces. For example, the frictional / interference fit can be provided by a retaining device, such as a push-in retaining ring that engages the shaft 143 and allows translation of the shaft 143 relative to it in one direction but prevents or inhibits translation of the shaft 143 relative to it in the opposite direction. Such a retaining device can be coupled to the rear support 151 such that translation of the shaft 143 relative to it includes translation of the shaft 143 relative to the conduit 130. The retaining device can be oriented to allow translation of the shaft 143 toward the inlet 131 while preventing translation toward the outlet 132. In some examples, friction may be sufficient to prevent movement of the shaft 143 under normal operating conditions, but the shaft 143 may be able to translate toward the inlet 131 in response to a sufficiently strong thrust applied to the shaft, for example, via a tool inserted through the inlet 132. In these examples, pushing shaft 143 to drive the shaft to translate can correspond to the aforementioned actuation of adjustment mechanism 148.

[0042] Because shaft 143 is connected to impeller body 145, the relative movement between the shaft and the impeller body is restricted to rotation only about axis 149. When shaft 143 translates along axis 149, this also causes impeller body 145 to translate along axis 149. Therefore, in summary, actuation of adjusting mechanism 148 causes impeller body 145 to translate along axis 149. This can be referred to herein as “adjusting” the position of impeller 140, and therefore impeller 140 can also be referred to herein as adjustable impeller 140.

[0043] Figure 2A and 2B The illustration shows the effect of adjusting the impeller 140 via the adjusting mechanism 148. Figure 2A In this design, the tip clearance of the blade tip 142 is d1, where the tip clearance refers to the minimum distance between the blade tip 142 and the inclined wall of the transition zone 135 of the impeller chamber 133. This condition may occur, for example, after the pump 100 has been initially assembled. Due to the manufacturing tolerances involved, the tip clearance d1 is relatively large, and therefore the performance of the pump 100 may be reduced. However, by adjusting the position of the impeller 140 toward the inlet 131 (e.g., ...), the performance can be improved. Figure 2A (As indicated by the middle arrow), so that... Figure 2B The state shown. In Figure 2A state and Figure 2B During the transition between states, the translation of the impeller 140 toward the inlet 1341 causes the blade tip 142 to move closer to the wall of the transition zone 135 due to the inclination of the wall. Therefore, in Figure 2B In the state shown, the tip clearance of the blade tip 142 has been reduced to less than d1 by d2. In this way, any desired tip clearance, including relatively small ones, can be obtained by adjusting the impeller 140. Furthermore, even if the individual impellers 140 have different dimensions due to manufacturing tolerances, each impeller can be adjusted to have a similar tip clearance.

[0044] In some examples, it can be determined whether the desired tip clearance has been achieved by observing and / or measuring the position of the blade 141. For example, in some pumps, the blade 141 can be seen through the impeller chamber inlet 134 (especially if the inlet portion 131 is not already installed at the impeller chamber inlet), and this allows observation and / or measurement of the position of the blade 141 relative to the wall of the chamber 133 at the transition zone 135. In some examples, a portion of the conduit 130 and the housing 110 may be made of a transparent material, so the position of the blade 141 can be observed through this portion. In another example, a special port or opening (not shown) can be provided through the housing 110 and the conduit 130, through which visual observation and / or measuring devices can be used to measure the position of the blade 141, such as a rod depth micrometer, which can be inserted through the port or opening to engage the blade 141 and determine its position. In examples with such ports, once adjustment has been completed, the port or opening can be closed using a plug and / or epoxy resin.

[0045] In other examples, directly observing or measuring the position of blade 141 may be impractical or otherwise undesirable. In such examples, impeller 140 can still be adjusted to the desired position in other ways, which will be referenced below. Figure 3 Describe it. Figure 3 The illustration shows an example method for adjusting an adjustable impeller in a pump, such as pump 100 (or pump 400 hereinafter). This method can also be referred to as a method for tuning a pump because adjusting the impeller affects the pump's performance and can be used to achieve a desired performance level.

[0046] In box 202, the initial position of the impeller can be set. In some cases, this may include assembling the pump and placing the impeller in the initial position. In other examples, this may include changing the position of the impeller of an already assembled pump. In some examples, box 202 is omitted and the process can continue from any position of the impeller (e.g., any position the impeller happens to be in after assembly). In examples where the initial position of the pump is adjusted to a predetermined position, the predetermined position can be defined in any desired manner. For example, in some embodiments, the initial position may be a position corresponding to a predetermined number of revolutions away from the fully forward position, where the impeller blades touch the wall of the impeller chamber. That is, the impeller can be adjusted until it touches the impeller chamber, which will be noticed when the adjustment mechanism encounters resistance, and then the adjustment mechanism can be returned to the predetermined number of revolutions from that position. This position can reduce the time spent finding its final position because the impeller can start from a position closer to its target position (relatively close to the wall). As another example, in some embodiments, the initial position may be a fully backward position. In some cases, this may require more time for testing, but it avoids the risk of damaging the blades due to contact with the wall. In other examples, different initial positions can be used.

[0047] Boxes 204, 206, 208, and 210 form a loop, which is referred to herein as the tuning cycle. The tuning cycle can be repeated iteratively until a negative result is obtained at box 208.

[0048] In box 204, the pump is connected to the liquid circuit and operated to flow liquid, and the pump's performance is tested. Specifically, at least one pump performance metric is measured. Any desired metric related to pump performance and affected by tip clearance can be used in this step. Examples of pump performance metrics affected by tip clearance include: the pressure differential (the higher the better) generated by the pump between the inlet and outlet, also known as head or head difference; and the pump's flow rate (liquid volume per unit time) (the higher the better). In some examples, both pressure differential and flow rate can be measured and can be used together. For example, the pressure differential of a given pump may vary depending on the flow rate, so both can be measured. For example, in some embodiments, the metric may include the pressure differential at a predetermined flow rate. Additional examples of pump performance metrics considered herein include power consumption at a given flow rate and pressure, power consumption and / or impeller speed required to achieve a desired flow rate, pressure, and / or flow rate at a given impeller speed and / or power consumption, vibration, and noise.

[0049] In box 206, the measured pump performance can be compared to one or more target pump performance metrics. For a given type of pump being tested, target pump performance metrics may have already been predetermined. For example, targets can be determined by measuring the performance of a pump known to have the desired characteristics, including the desired blade tip clearance. Alternatively, target pump performance metrics can be determined based on modeling or other empirical tests that correlate blade tip clearance with performance.

[0050] In box 208, based on the comparison in box 206, it is determined whether the measured performance of the pump is worse than the target performance. In other words, it is determined whether the measured performance meets the target criteria, where the target criteria correlate the measured performance of the pump with the target performance, and meeting the target criteria means that the pump performance is not worse than the target performance.

[0051] For certain performance metrics, lower values ​​are considered poorer or less desirable. Therefore, when using such metrics, if the measured performance metric is greater than the target value, it can be determined that the measured performance meets the target standard (i.e., is not worse than the target). Conversely, if the measured performance metric is less than the target value, it can be determined that the measured performance does not meet the target standard (i.e., is worse than the target). (A measured performance equal to the target can be considered as meeting the standard in some examples, and as not meeting the standard in others.) Examples of lower values ​​indicating worse performance metrics include pump flow rates (e.g., gallons per minute), the pressure differential between the pump inlet and outlet, pump efficiency (e.g., flow rate per watt of power consumption), and pressure and / or flow rate achieved at a given impeller speed and / or power consumption. In particular, in some examples, the metric considered in box 208 could be the pressure differential measured at a predetermined flow rate (e.g., 2.0 gallons per minute), in which case a lower value is considered a worse value.

[0052] For other performance metrics, higher values ​​are considered worse or less desirable. Therefore, when using such performance metrics, if the measured performance metric is less than the target value, it can be determined that the measured performance meets the target standard (i.e., is not worse than the target). Conversely, if the measured performance is less than the target value, it can be determined that the measured performance does not meet the target standard (i.e., is worse than the target). A measured performance equal to the target can be considered as meeting the standard in some examples, and as not meeting the standard in others. Examples where higher values ​​indicate worse performance metrics include the time required for a pump to empty a certain volume of fluid, power consumption at a given flow rate and pressure, power consumption and / or impeller speed required to achieve a desired flow rate, vibration levels, and noise levels.

[0053] If the performance is worse than the target specification (does not meet the target standard) (box 208 = Yes), the tip clearance has not reached the desired amount, meaning the tip is too far from the impeller chamber wall. Therefore, in this case, the process proceeds to box 210 and the impeller position is adjusted. Specifically, the impeller position is adjusted to bring it closer to the inlet side, and thus closer to the impeller chamber wall. Adjusting the impeller position at box 210 may include, for example, inserting a tool into the pump to adjust the pump's adjustment mechanism. For example, in embodiments where the adjustment mechanism includes a locating screw, a screwdriver or hex wrench or other such tool may be inserted into the pump (e.g., via the outlet opening in some examples) to turn the locating screw.

[0054] In some examples, the impeller position can be adjusted by a predetermined amount, such as a quarter turn of the locating screw of the adjusting mechanism. The purpose of using a predetermined adjustment is to avoid over-adjusting the impeller and thus preventing the blades from entering the chamber wall. The desired blade tip clearance may be very small (approximately a few thousandths of an inch in some examples), so in some examples the predetermined adjustment may also be relatively small to reduce the possibility of adjusting the impeller beyond its optimal position and entering the chamber wall.

[0055] In some examples, the predetermined adjustment amount is fixed and remains unchanged from one iteration of the tuning cycle to the next. In other examples, the predetermined amount of impeller adjustment can change from one tuning cycle to the next. For example, in some implementations, the adjustment amount can be dynamically determined in each iteration of the tuning cycle based on the current performance variable of that cycle (i.e., the difference between the measured performance and the target performance). For example, a predetermined table or formula can be prepared in advance, associating various performance variables with corresponding allowable adjustment amounts, and the adjustment amount for the current iteration of the cycle can be determined based on the current performance variable with reference to that table or formula. Using a predetermined adjustment amount based on changes in the current performance variable allows for larger adjustments when the difference is large, assuming that a large difference means the impeller is relatively far from the position, and therefore a larger adjustment can be safer. Then, as the impeller gets closer to the correct position, the difference becomes smaller, and the adjustment amount can be reduced accordingly to reduce the risk of exceeding the target position.

[0056] Once the impeller position has been adjusted in box 210, the process loops back to box 204 and executes a new iteration through steps 204-208. This loop through boxes 204-210 can be repeated over and over again, with the impeller gradually adjusted with each iteration of the loop, until it is determined in box 208 that the measured performance is no worse than the target performance. At this point, the loop stops, and the process continues to box 212.

[0057] When the measured performance is equal to or greater than the target performance (meeting the target standard) (box 208 = No), this means that the blade tip clearance has reached the desired value. Therefore, box 212 confirms that the impeller is correctly positioned relative to the impeller chamber, and thus no further adjustments to the impeller are required.

[0058] In some examples, the adjustment mechanism can be designed to securely hold the impeller in place without further assistance after adjustment, meaning that the friction between the locating screw and the sleeve / nut is sufficient to prevent retraction under normal operating conditions. For example, in some implementations, the locating screw or threaded sleeve / nut may include an integral locking feature that increases friction between the screw and the sleeve to help prevent loosening, such as a compliant material that increases friction (e.g., nylon in a nylon lock nut).

[0059] In other examples, to further reduce the risk that vibration or other forces might ultimately cause the locating screws and sleeves / nuts to move, separate securing mechanisms can be used to further secure the impeller in the desired position. For example, an additional mechanical lock, separate from the screws and sleeves / nuts, can be attached to one of them to help secure the shaft in place. For example, a locking nut, a tightening nut, or other such fastener can be attached to the screws and / or sleeves after adjustment to prevent movement. In other examples, instead of fixing the locating screws and sleeves / nuts relative to each other, the shaft can be secured relative to one of the support structures that hold it in place. For example, the front support structure may include a retaining screw arranged to translate radially within the front support structure when actuated and thus engage the radially outer surface of the front portion of the impeller shaft when tightened. In such an example, the retaining screw can be loosened during impeller adjustment to allow the shaft to translate relative to the support, and then tightened after adjustment to secure the shaft to the front support. Other types of retention mechanisms can be coupled to the front or rear support to engage the shaft and hold it in place, as is familiar to those skilled in the art.

[0060] In other examples, chemical threadlockers can be used to secure the adjusting mechanism and thus the shaft in place. Chemical threadlockers contain compounds designed to be applied between the screw and the sleeve / nut and to cure over time to hold the threaded components relative to each other. The chemical threadlocker can be applied to the threads of the adjusting mechanism, for example, during assembly, and then tested and adjusted before the threadlocker has cured. After adjustment, the threadlocker can be finally cured, thus locking the impeller in place. In other examples, the chemical threadlocker can be applied after adjustment is complete (e.g., in this case, the threadlocker may not cover all threads, but in some cases, securing the exposed portions of the positioning screw and sleeve / nut may be sufficient).

[0061] Turn now Figures 4 to 13 Another example pump will be described in the form of pump 400. Pump 400 is an example configuration of pump 100 described above. Therefore, some components of pump 400 are similar to the corresponding components already described above (e.g., their example configurations), and thus the description of the components of pump 100 above applies to similar components of pump 400, and therefore some repeated descriptions of pump 400 can be omitted. Corresponding components can be designated using reference numerals with the same last two digits, such as 110 and 410. It should be understood that pump 400 is only one possible configuration of pump 100, and pump 100 is not limited to pump 400. Similarly, the various components of pump 400 are examples corresponding to the various components of pump 100, but the various components of pump 100 are not limited to the corresponding components of pump 400.

[0062] Figure 15 The illustration shows another example method that can be used to adjust the adjustable impeller of a pump, such as pump 100 (or pump 400 below). Figure 15 The method is Figure 3 This is a modified version of the method. This method can also be called the method for tuning pumps because impeller adjustment affects pump performance and can be used to achieve the desired performance level. This method can be particularly useful, for example, when it is desirable to position the blade tip close enough to the wall to produce the desired performance level, but not too close to the wall to avoid other problems such as tip impact or reduced reliability (as opposed to positioning the blade tip as close to the wall as possible, which may produce better performance but could reduce pump reliability).

[0063] In boxes 302 and 304, the initial position of the impeller is set, the pump is operated, and pump performance parameters are measured. Boxes 302 and 304 can be similar to those described above. Figure 3 The descriptions of boxes 202 and 304 are omitted here, as their repeated descriptions are omitted.

[0064] In box 306, the measured performance metrics are compared with the first objective and the second objective. The first objective can be the lower objective and the second objective can be the upper objective.

[0065] In block 308, it is determined whether the measured performance is worse than the first target. A performance worse than the second target may indicate that the blade tip is farther from the impeller chamber wall than expected. Therefore, if the performance is worse than the second target, the process continues to block 310, where the impeller position is adjusted along a first direction, for example toward the inlet, so that the blade tip moves closer to the impeller wall. The process then returns to block 304 to perform another iteration of the tuning cycle 304-314. If the performance is not worse than the second target, the process continues to block 312.

[0066] In block 312, it is determined whether the measured performance exceeds the second target. Performance exceeding the second target may indicate that the tip is closer to the impeller chamber wall than expected. Therefore, if the performance exceeds the second target, the process continues to block 314, where the impeller position is adjusted along a second direction, for example toward the outlet, which allows the tip to be moved further away from the wall. The process then returns to block 304 to perform another iteration of the tuning cycle 304-314. If the performance does not exceed the second target, the process continues to block 316, where it is determined that the impeller is correctly positioned.

[0067] Various aspects of pump 400 are visible in multiple figures, and different figures may show certain aspects better than others. Therefore, they are not described below in a strict order. Figures 4 to 13 For each of these, the various aspects of pump 400 will be described below with reference to some of the figures most relevant to the particular aspect being discussed. Figure 4 and Figure 5 Pump 400 is shown in both a perspective view and an exploded view. Figure 6 An exploded view of the impeller assembly 473 of the pump 400 is shown; Figure 7 The impeller 440 of pump 400 is shown in a 3D view; Figure 8 The impeller 440 and the rear portion 433b of the impeller chamber of the pump 400 are shown in a perspective view. Figure 9 Including impeller 440 and the rear portion 433b of the impeller chamber along Figure 8 The cross section taken from plane 9-9 in the middle; Figure 10 Including pump 400 along Figure 4 A cross-sectional view taken from plane 10-10 in the image; Figure 11 and Figure 12 Each includes Figure 10 Enlarged views of regions 11 and 12 in the image; and Figure 13 Includes a three-dimensional cross-sectional view of the pump, where the cross-section is along... Figure 4 It is cut off from the plane 10-10.

[0068] like Figure 5As shown, pump 400 includes multiple sub-assemblies, including a first stator sub-assembly 471, a second stator sub-assembly 472, an impeller sub-assembly 473, an inlet sub-assembly 475, and an outlet sub-assembly 476. Each of these sub-assemblies will be described in more detail below.

[0069] like Figure 5 and Figure 6 As shown, the first stator subassembly 471 and the second stator subassembly 472 respectively include a first stator portion 420a and a second stator portion 420b. Additionally, the first stator subassembly 471 and the second stator subassembly 472 include PCBs 425, which constitute a split PCA, such as the split PCA described in U.S. Patent Application No. 17 / 976,406, filed October 28, 2022, entitled "Axial Pump with Split Printed Circuit Board Assembly (PCA)," the entire contents of which are incorporated herein by reference. PCBs 425 are electrically connected to the first stator portion 420a and the second stator portion 420b, for example, by soldering or other electrical connections. Figure 5 As shown, the first stator sub-assembly 471 and the second stator sub-assembly 472 are located on opposite sides of the impeller sub-assembly 473. Therefore, during the assembly of the pump 400, the first stator sub-assembly 471 and the second stator sub-assembly 472 can be positioned as follows: Figure 5 As shown in the exploded view, the stator sub-assemblies 471 and 472 can then be moved laterally (in the directions indicated by arrows 402 and 403) to position them together around the impeller assembly 473. Once assembled in this way, stator portions 420a and 420b are positioned adjacent to and radially around the impeller chamber center portion 436 (except for small areas at the top and bottom of the center portion 436 that are not surrounded). Furthermore, the PCB 425 is electrically connected because the first stator sub-assembly 471 and the second stator sub-assembly are coupled to the impeller assembly 473.

[0070] like Figure 5 and Figure 6 As shown, the impeller sub-assembly 473 includes an impeller chamber 433 and an impeller 440 housed within the impeller chamber 433. The impeller chamber 433 includes a front portion 433a and a rear portion 433b. The front portion 433a includes a bore 467, and the rear portion 433b includes a bore 450. Figure 6 As indicated by the arrows, when assembling the impeller sub-assembly 473, the front portion 433a and the rear portion 444b are joined together, with the impeller 440 partially positioned within the bore 467 and partially positioned within the bore 450. Figure 5 and 6As shown, the front portion 433a of the impeller chamber includes an impeller chamber inlet 434, a transition zone 435, a central portion 436 of the impeller chamber, and a connecting portion 438. These portions surround and define the orifice 467. Figure 6 As shown, the rear portion 433b of the impeller chamber includes a joining portion 455 configured to engage with a joining portion 438 of the front portion 433a (e.g., received in the joining portion of the front portion) to join the front portion 433a and the rear portion 433b together. The joining portion 455 surrounds and defines an aperture 450.

[0071] like Figure 7 and Figure 9 As shown, the impeller 440 includes an impeller body 445, blades 441 that project radially from the impeller body 445 and rotate axially and circumferentially around the outer surface of the impeller body 445, a shaft 443 including a front end 443a and a rear end 443b, a bearing housing 461, a bearing 447 housed within the bearing housing 461 and connected to the rear end 443b of the shaft 443, a bearing 449 housed within the impeller body 445 and connected to the shaft 443, and a magnet 462 housed within the impeller body 445. Bearings 447 and 449 rotatably connect the impeller body 445 to the shaft 443, thus enabling the impeller body 445 to rotate around the axis 439 (see [link to image]). Figure 10 The impeller body 445 rotates relative to shaft 443. Shaft 443 is coupled to impeller chamber 433 as described below, and therefore, when impeller body 445 rotates about shaft 443, impeller body also rotates relative to impeller chamber 433. Magnet 462 interacts with the magnetic field generated by stator 420, which causes impeller body 445 to rotate.

[0072] like Figure 6 , Figure 10 and Figure 13 As shown, when subassembly 473 is assembled, impeller 440 is housed within impeller chamber 433, wherein the front end of the impeller is connected to the front portion 433a of impeller chamber 433, and the rear end of the impeller is connected to the rear portion 433b of impeller chamber 433. More specifically, as Figure 10 and Figure 13 As shown, the front end 443a of the shaft 443 of the impeller 440 is inserted into the hub 484 of the front support 444. The front support 444 is connected to the wall of the impeller chamber 433 at a position between the inlet portion 434 and the transition zone 435. Therefore, when the front end 443a is engaged with the front support 444, the front support 444 supports the shaft 443 relative to the impeller chamber 433. Similarly, the rear end 443b of the shaft 443 is inserted into and engaged with the rear support 451 of the rear portion 433b of the impeller chamber, as shown. Figure 9 , Figure 10 , Figure 12 and Figure 13As shown. Specifically, the adjustment mechanism 448 is connected to the rear support member 451, as... Figure 9 and Figure 12 As shown, the rear end 443b of shaft 443 is connected to the adjustment mechanism 448. Furthermore, as... Figure 9 and Figure 12 As shown, the bearings 447 and 449 that connect the impeller body 445 to the shaft 443 include a set of radial bearings 447a connected to the rear portion 443b of the shaft and a set of radial bearings 449 connected between the front end 443a and the rear portion 443b (but closer to the front end 443a). These radial bearings 447a and 447b allow the impeller body 445 to rotate smoothly and easily relative to and about the shaft 443. Bearing 447 also includes a thrust bearing 447b. Figure 9 As shown, the thrust bearing 447b engages with the flange of the shaft 443 on one side and with the retainer 463 on the opposite side to absorb axial thrust and prevent the impeller body 445 from translating relative to the shaft 443.

[0073] Now refer to Figures 7 to 13 The rear support 451 and the adjustment mechanism 448 are described in more detail. The rear support 451 includes a cylinder 452 disposed within a bore 450, a nut retaining portion 453 coupled to one end of the cylinder 452, and an attachment portion 454 extending radially from the cylinder 452 to engage the cylinder 452 to a mating portion 455. Although not visible in the figures, the attachment portion 454 is arranged not to obstruct fluid flow through the chamber 433, through the space between the mating portion 455 and the cylinder 452, and around the attachment portion 454. The nut retaining portion 453 is coupled to a nut 448a of the adjustment mechanism 448. The nut 448a has a bore and internal threads in the bore, which are configured to engage the external threads of a locating screw 448b of the adjustment mechanism 448 inserted therein. This engagement may also be referred to herein as a “threaded” engagement or a “threaded” engagement. The locating screw 448b has a socket 448c to receive a tool, thereby allowing actuation (i.e., rotation) of the locating screw 448b. The locating screw 448b is coupled to the rear end 443b of the shaft 443. Therefore, the rear end 443b of the shaft 443 is coupled to and supported by the engagement portion 455 of the rear portion 433b via the rear support 451. Because the rear portion 443b of the shaft 443 is coupled to the rear portion 433b of the impeller chamber and the front portion 433a of the shaft 443 is coupled to the front portion 433a of the impeller chamber, the shaft 443 is fixedly coupled to and supported by the impeller chamber 433 when the front portion 433a and the rear portion 433b are assembled.

[0074] The aforementioned adjustment mechanism 448 is adjustable to change the position of the shaft 443 relative to the impeller chamber 433. Rotating the positioning screw 448b causes it to translate relative to the nut 448a along the axis of rotation 439. Because the positioning screw 448b is connected to the shaft 443 and the nut 448a is connected to the impeller chamber 433 (via the rear support 451), the relative translation between the positioning screw 448b and the nut 448a causes the shaft 443 to translate relative to the impeller chamber 433 along the axis of rotation 439. Rotating the positioning screw 448b in one direction causes the shaft 443 to translate toward the inlet 431, while rotating it in the opposite direction causes the shaft 443 to translate away from the inlet 431. Therefore, rotation of the positioning screw 448b represents one actuation embodiment of the adjustment mechanism 448. As described above regarding pump 100, the adjusting mechanism 448 can be adjusted after pump 400 is assembled to change the position of impeller 440 and thereby adjust the blade tip clearance between blade tip 442 and the inclined wall of transition zone 435. Figure 11 Best viewed. Actuation can be achieved by inserting a tool, such as a hex screwdriver or screwdriver, through outlet 432 and through opening 468 in guide 465 into socket 448c of adjustment mechanism 448.

[0075] The impeller chamber 433 is also connected to various support structures and / or various surfaces that form part of the housing 410 and facilitate the connection of other sub-assemblies. For example, as Figure 6 As shown, the rear portion 433b includes a fastener holder 459 having a hole 458 to receive a fastener 477. Figure 5 and Figure 6 As shown, the front portion 433a includes a hole 437, and when the front portion 433a and the rear portion 433b are joined together, the hole 437 is aligned with the hole 458. Therefore, as Figure 5 As shown, fastener 477 is inserted through holes 437 and 458 to secure the front portion 433a and the rear portion 433b in the connected state. Additionally, as... Figure 6 As shown, the rear portion 433b also includes holes 457 that receive fasteners 479, such as... Figure 5 As shown. Similarly, the front portion 433a includes a hole 485 to receive a fastener 479, as shown. Figure 5 and Figure 6As shown. These fasteners 479 are used to connect various sub-components together, as described below. In some examples, the front portion 433a may also include holes 481, which can be used to fill the pump 400 with epoxy resin after assembly to make the pump 400 waterproof and also to facilitate the transfer of heat from the pump 400 components to the coolant by removing the air gap. Furthermore, the impeller chamber 433 is connected to the housing portions 410i, 410j, 410k, and 410L.

[0076] The inlet subassembly 475 includes an inlet 431 and a vibration isolator 466. The outlet subassembly 476 includes an outlet 432 and a vibration isolator 466. In the illustrated example, inlet 431 and outlet 432 include hose barbed fittings. In other examples, other types of fluid fittings may be used instead of hose barbed fittings. Pump 400 may be coupled to another device (e.g., the chassis of a computing device in which pump 400 is mounted) via the vibration isolator. Vibration isolator 466 may be rubber, silicone, or another compliant material that helps absorb vibrations generated by pump 400 and prevents (or reduces) the transmission of these vibrations to the device in which pump 400 is located. Figure 6 As shown, outlet 432 includes a engagement portion 487. This engagement portion 487 is configured to engage with engagement portion 456 of the rear portion 433b of the impeller chamber. Engagement portion 456 is located in… Figure 8 and Figure 9 The best visibility is in the middle, and the joint between the joint portions 487 and 456 is in Figure 10 , Figure 12 and Figure 13 As shown in the diagram. Figure 10 , Figure 12 and Figure 13 As shown, outlet 432 may also include a flow guide structure 465 that guides the liquid flow as it leaves impeller chamber 433 and enters outlet 432. This can help reduce turbulence or eddies that may impair pump performance.

[0077] Additionally, the inlet subassembly 475 and the outlet subassembly 476 include portions of the housing 410. For example... Figure 5 As shown, the inlet subassembly 475 and the outlet subassembly 476 can be positioned on opposite axial sides of the impeller subassembly 473. Therefore, during the assembly of the pump 400, the inlet subassembly 475 and the outlet subassembly 476 can be positioned as follows: Figure 5The components are positioned as shown and then moved toward each other (in the directions indicated by arrows 404 and 405) until inlet 431 is fluidly connected to one side of impeller chamber 433 and outlet 432 is fluidly connected to the other side of impeller chamber 433. In some examples, this assembly step can be performed after the two stator sub-assemblies 471 and 472 have been assembled onto impeller sub-assembly 473. Once inlet 431, outlet 432, and impeller chamber 433 are connected, they form conduit 430 through which liquid coolant can flow along the central axis 439 of the conduit.

[0078] like Figure 4 and 5 As shown, pump 400 includes a housing 410. The housing 410 may be composed of multiple interconnected portions. Specifically, the aforementioned subassemblies may include these portions of housing 410. In particular, housing 410 includes an inlet end wall portion 410a and side wall portions 410b and 410c connected to the inlet end wall portion 410a. These portions 410a-c are part of an inlet subassembly 475. Housing 410 further includes an outlet end wall portion 410f and side wall portions 410g and 410e. These portions 410e-g are part of an outlet subassembly 475. When assembled, the aforementioned portions 410a-c and 410e-g define the outer peripheral sidewalls of housing 410. Housing 410 also includes a top portion 410d connected to a portion of a first stator subassembly 471 and a top portion 410h connected to a portion of a second stator subassembly 472 and a top portion 410h of a second stator portion 420b. The housing also includes housing top portions 410i, 410j, 410k, and 410L, which are coupled to the conduit 430 and are part of the impeller sub-assembly 473. Top portions 410d, 410h, and 410i-410L form the top surface of housing 410. It should be noted that the top surface of housing 410 is not necessarily uniform and does not necessarily completely cover the entire pump 400. For example, the tops of stator portions 420a and 420b may be exposed and substantially coplanar with the top surface of housing 410 (this can allow the height dimension of pump 400 to be reduced to the absolute minimum possible for a given size of stator 420). Some of the housing portions may include holes 478 (only some are marked) arranged to receive fasteners 479 to join sub-assemblies together. For example, in some embodiments (including...) Figure 5 In the embodiment illustrated herein, the impeller subassembly 473 includes fasteners 479 in the form of, for example, spring-biased push pins, and each of these fasteners can be inserted into a hole 478 in one or more subassemblies to secure the respective subassemblies together. A single fastener 479 can be inserted through two holes 478 in two different subassemblies, for example, Figure 5The fastener marked 479' can be inserted into the two holes marked 478', which are part of the stator subassembly 472 and the outlet subassembly 476. Other fasteners 479 and holes 478 can be connected similarly.

[0079] The bottom portion of housing 410 (which is generally not visible in the figures and is not marked in this document) may be constructed in a similar manner to the top portion of housing, so repeated descriptions of these portions are omitted.

[0080] Figure 14 The illustration includes a schematic diagram of example system 580 and electronic device 590. System 580 includes electronic device 590 and a liquid cooling circuit 589 coupled to electronic device 590. The system may also include additional electronic devices (not shown). For example, system 580 may include one or more racks for the electronic devices. For ease of description, electronic device 590 is illustrated in a state of being installed in system 580; however, it should be understood that electronic device 590 may be provided separately from system 580.

[0081] The liquid cooling circuit 589 includes a pump 500 (described below), one or more coolant supply lines 587, one or more coolant return lines 588, and one or more additional cooling circuit components 583, such as heat exchangers, rack-level, row-level or data center-level coolant distribution units, coolers, or other cooling components familiar to those skilled in the art.

[0082] Electronic device 590 includes a PCB 595 (such as a substrate or motherboard of a computing device) and a base 594 that supports and houses the PCB 595. PCB 595 includes electrical components 591, such as a processor, power supply unit, storage device, hardware accelerator, or any other electrical component. Electronic device 590 further includes a cold plate 592 thermally coupled to the electrical components 591.

[0083] Electronic device 590 further includes a pump 500 disposed in a base frame 594. Pump 500 can be any of the pumps described above, such as pump 100 and pump 400. Pump 500 is fluidly connected to cold plate 592 via coolant line 596. Pump 500 is electrically connected to PCB 595 via wire / cable 559 connected to connector 598 of PCB 595. Thus, PCB 595 can power pump 500 and / or communicate with pump. Pump 500 includes an inlet 531 that can be coupled to a liquid coolant supply line 587 of liquid cooling circuit 589 of system 580, which supplies liquid coolant to pump 500. Pump 500 outlet 532 is coupled to coolant line 596. The outlet of the cold plate 592 can be connected to a liquid coolant return line 588 of the liquid cooling circuit, which returns the liquid coolant to the rest of the circuit for final cooling (e.g., at a heat exchanger). Therefore, when the electronic device 590 is installed in the system 580 and fluidly connected to the system's liquid cooling circuit 589, liquid coolant from the circuit 589 can flow through the pump 500 and the cold plate 592. Specifically, the pump 500 can be configured such that (or at least facilitate) the flow of liquid coolant through the cold plate 592 to cool the electrical component 591.

[0084] The above description describes various types of electronic circuits or devices. As used herein, “electronic” is intended to be understood broadly to include all types of circuits / devices that utilize electrical energy, including digital and analog circuits, direct current (DC) and alternating current (AC) circuits, as well as circuits / devices for converting electrical energy into another form of energy and for using electrical energy to perform other functions. In other words, as used herein, there is no distinction between “electronic” circuits / devices and “electrical” circuits / devices. In some cases, certain electronic circuits / devices may include processing circuitry. Processing circuitry includes circuitry configured with logic for performing various operations. The logic of the processing circuitry may include dedicated hardware for performing various operations, software (machine-readable and / or processor-executable instructions) for performing various operations, or any combination thereof. In embodiments where the logic includes software, the processing circuitry may include a processor for executing the software instructions and a memory device for storing the software. The processor may include one or more processing devices capable of executing machine-readable instructions, such as a processor, processor core, central processing unit (CPU), controller, microcontroller, system-on-a-chip (SoC), digital signal processor (DSP), graphics processing unit (GPU), etc. In cases where the processing circuitry includes dedicated hardware, which is attached to or replaces the processor, the dedicated hardware can include any electronic device configured to perform a specific operation, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a complex programmable logic device (CPLD), discrete logic circuits, hardware accelerators, hardware encoders, etc. The processing circuitry can also include any combination of dedicated hardware and a processor plus software.

[0085] It should be understood that both the general description and the detailed description provide illustrative examples of implementations that are inherently explanatory and are intended to provide an understanding of the disclosure without limiting its scope. Other examples of the disclosure will be apparent to those skilled in the art based on considerations of the content herein. For example, various mechanical, compositional, structural, electronic, and operational changes may be made to the disclosed examples without departing from the scope of the disclosure, including, for example, the addition, removal, alteration, substitution, or rearrangement of elements of the disclosed examples, as will be apparent to those skilled in the art in considering the disclosure. Furthermore, it will be apparent to those skilled in the art that certain features or aspects of the teachings may be used independently (even if they are disclosed together in some examples) or together (even if disclosed in separate examples) where feasible. In some instances, well-known circuits, structures, and techniques have not been shown or described in detail to avoid obscuring these examples. Therefore, the appended claims are intended to provide their fullest scope, including equivalents under applicable law, and are not limited to the examples disclosed herein.

[0086] Unless otherwise expressly stated, examples, implementations, or other similar references mentioned herein should be understood as predictive or hypothetical examples, not as devices that have actually been manufactured (e.g., prototypes). Similarly, unless otherwise expressly stated, the quality or characteristics of the examples mentioned should be understood as estimates or expectations based on an understanding of the relevant physical principles involved, the application of theories or modeling, and / or the inventors' past experience, rather than as the result of tests conducted on a physical device.

[0087] Furthermore, the spatial, positional, and relational terms used herein are chosen to aid the reader in understanding examples of the invention, but are not intended to limit the invention to specific frames of reference, orientations, or positional relationships. For example, spatial, positional, and relational terms such as “up,” “down,” “side,” “below,” “below,” “lower,” “above,” “upper,” “near,” and “far” can be used herein to describe direction or to describe the spatial relationship between one element or feature and another element or feature as illustrated in the figures. These spatial terms are used relative to the frame of reference in the figures and are not limited to a specific frame of reference in the real world. Moreover, if a different frame of reference is considered than that illustrated in the figures, the spatial terms used herein may require different interpretations in that different frame of reference. Furthermore, the orientations of the items illustrated in the figures are chosen for ease of explanation and description, but in actual implementations, the orientations of the items may differ.

[0088] Additionally, unless the context otherwise indicates, the singular forms “an,” “a,” and “the” are intended to include the plural forms as well. Furthermore, the terms “comprising,” “including,” “including,” etc., specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups. Unless expressly stated otherwise, components described as interconnected may be directly electrically or mechanically connected, or they may be indirectly connected via one or more intermediate components.

[0089] And / or: Occasionally, the phrase “and / or” is used in conjunction with a list of items in this article. This phrase means that any combination of items in the list can be included, from a single item to all items, and any permutation in between. Thus, for example, “A, B and / or C” means one of “{A}, {B}, {C}, {A, B}, {A, C}, {C, B}, and {A, C, B}”.

[0090] Unless the context otherwise indicates, mathematical and geometric terms are not necessarily used according to their strict definitions, as those skilled in the art will understand that, for example, substantially similar elements that function in substantially similar ways can readily fall within the scope of descriptive terms, even if those terms have strict definitions. Furthermore, unless otherwise stated herein or implied by the context, the use of approximate terms such as “substantially,” “approximately,” “about,” “around,” “roughly,” etc., should be understood to mean that mathematical precision is not required, but rather refers to a range of variations including, but not strictly limited to, the stated values, properties, or relationships. In particular, in addition to any ranges explicitly stated herein (if any), the range of variations implied by the use of such approximate terms includes at least any insignificant variations and those typical in the relevant field for items of the type discussed due to manufacturing or other tolerances. In any case, unless otherwise indicated, the range of variations may at least include values ​​within ±1% of the stated values, properties, or relationships.

Claims

1. An axial flow pump for delivering liquid coolant to cool electronic devices, the axial flow pump comprising: A conduit defining a flow path from the inlet of the conduit to the outlet of the conduit, wherein the conduit includes a wall defining an impeller chamber that houses the impeller; The impeller is located in the duct, and the impeller includes: An axis extending parallel to the flow path; An impeller body rotatably coupled to the shaft, wherein the impeller body is rotatable relative to the shaft and the duct about a rotation axis parallel to the flow path; and One or more blades connected to the impeller body; A motor stator configured to drive the impeller body to rotate about the axis of rotation; A front support member that securely connects the front portion of the shaft to the impeller chamber; Rear support member, the rear support member being connected to the impeller chamber; and An adjustment mechanism is provided that connects the rear portion of the shaft to the rear support member. This adjustment mechanism is actuable to translate the impeller shaft and the impeller body relative to the guide tube. Actuation of the adjustment mechanism causes a change in the clearance between the blade tip of one or more blades and the wall of the impeller chamber. The adjustment mechanism includes an internal thread connected to the conduit and a positioning screw connected to the shaft, the internal thread and the positioning screw having an external thread engaging with each other.

2. The axial flow pump of claim 1, further comprising: A locking mechanism is configured to prevent movement of the shaft relative to the conduit and to prevent actuation of the adjustment mechanism in the application state.

3. The axial flow pump as described in claim 2, The locking mechanism includes a mechanical locking device.

4. The axial flow pump as described in claim 3, in, The adjustment mechanism includes a threaded sleeve, the threaded sleeve having an internal thread attached to the rear support; and The mechanical locking device includes a friction-increasing element coupled to the threaded sleeve, which prevents the positioning screw from rotating relative to the threaded sleeve.

5. The axial flow pump as described in claim 3, wherein The adjustment mechanism includes a threaded sleeve, the threaded sleeve having an internal thread attached to the rear support member; The mechanical locking device includes a locking nut or tightening nut attached to the positioning screw and / or attached to the threaded sleeve to prevent relative rotation therebetween.

6. The axial flow pump as described in claim 3, wherein The mechanical locking device includes a retaining screw configured to engage the front of the shaft to prevent relative rotation between the shaft and the front support.

7. The axial flow pump as described in claim 2, The locking mechanism mentioned above includes a chemical threadlocker.

8. The axial flow pump as described in claim 1, The positioning screw is connected to a first portion of the shaft, and a second portion of the shaft engages with a hub connected to the conduit, the shaft being supported by the hub and capable of rotation and translation relative to the hub.

9. The axial flow pump as described in claim 1, wherein The adjustment mechanism includes a threaded sleeve, which has internal threads and is attached to the rear support.

10. The axial flow pump as described in claim 9, The threaded sleeve includes an integral locking feature that prevents the positioning screw from rotating relative to the threaded sleeve.

11. The axial flow pump as described in claim 1, wherein, The positioning screw is coaxial with the axis of rotation and includes a socket facing the outlet, the socket being configured to receive a tool inserted along the axis of rotation through the outlet.

12. The axial flow pump as described in claim 1, wherein The impeller includes one or more radial bearings connected to the shaft and the impeller body, and one or more thrust bearings connected to the shaft and the impeller body.

13. The axial flow pump as described in claim 1, wherein, The impeller includes one or more magnets housed within the impeller body, and the motor stator is configured to drive the rotation of the impeller body by generating a magnetic field that interacts with the one or more magnets.

14. The axial flow pump as described in claim 1, The impeller chamber includes an inlet portion, a central portion, and a transition zone between the inlet portion and the central portion; In the transition zone, the wall defining the impeller chamber is inclined relative to the axis of rotation; and The gap between the blade tip and the wall defining the impeller chamber is the gap between the blade tip and the wall defining the impeller chamber at the transition zone.

15. The axial flow pump as described in claim 1, The one or more blades thereon protrude radially from the impeller body and spiral axially and circumferentially along the impeller body.

16. The axial flow pump as described in claim 1, The adjustment mechanism is actuated by a tool accessible via the outlet.

17. The axial flow pump as described in claim 13, wherein The motor stator includes two separate stator halves arranged on opposite lateral sides of the conduit, and each half includes a portion that protrudes partially above the conduit and a portion that protrudes partially below the conduit.

18. An electronic device comprising: Printed circuit board (PCB); Electrical components, which are connected to the PCB; Base frame, which houses the PCB; A cold plate, thermally coupled to the electrical component; as well as The axial flow pump as claimed in claim 1, wherein the axial flow pump is disposed within the base frame, and wherein the conduit of the axial flow pump is fluidly connected to the cold plate.

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