US20050183848A1 - Coolant tray of liquid based cooling device - Google Patents

Abstract

A liquid based cooling device includes a pump for driving a coolant through a coolant tray that is positionable on a heat generating device and a radiator that dissipates the heat into the surrounding. The coolant tray includes a housing on which coolant inlet and outlet are formed for receiving the coolant from the pump and discharging the coolant to the radiator. The coolant tray also forms a recess in which a thermally conductive base forming a coolant channel is received in a liquid tight manner. The pump includes a casing in which coolant inlet and outlet are formed. The inlet of the coolant tray is integrally connected to the outlet of the pump and the housing of the coolant tray and the casing of the pump are integrally formed with each other with an integrally formed conduit connected therebetween. This simplifies the manufacturing of the cooling device and reduces the overall size of the cooling device.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention generally relates to a cooling device using a liquid, such as water, as coolant, for cooling particularly a computer system, and in particular to a coolant tray of the cooling device that is positionable on a heat generating device of the computer system for effectively and efficiently removing heat from the heat generating device with the coolant flowing through an internal channel of the coolant tray.
• 2. The Related Art
• Conventionally, a heat sink, such as an aluminum extrusion having spaced fins, is positioned on and in physical engagement with a heat generating device, such as a central processing unit, of a computer system for removing heat from and maintaining proper operation temperature of the central processing unit. Such a heat sink is an air-cooling device that removes heat from the central processing unit with airflows. However, such an aluminum extrusion heat sink is subject to limitation in removing a great amount of heat.
• A water based cooling device is thus employed in computer systems of high speed that generate a great amount of heat to replace the conventional aluminum extrusion heat sink. In addition to the enhanced capacity of heat removal, the liquid based cooling device is advantageous in small size, which is of particular importance in the current trend of miniaturization of the computer industry, and is thus particularly suitable for portable computers, which is of a much smaller size than a fixed computer, and often requiring much higher heat removal rate.
• A liquid based cooling device for computers is comprised of a coolant tray positionable on and in physical contact with a heat generating device of the computer, such as a central processing unit, and a radiator spaced from the coolant tray and often located in surroundings having temperature lower than that of the central processing unit. A coolant pump is arranged between the coolant tray and the radiator for circulating a liquid coolant, such as water, between the coolant tray and the radiator, which transfers the heat absorbed by the coolant flowing through the coolant tray to the radiator at which the heat is dissipated into the surroundings.
• Conduits, such as pipes, are connected among the coolant pump, the coolant tray, and the radiator to complete a circulation loop of the coolant. In practice, at least three pipes are required, respectively for connection between the coolant tray and the coolant pump, connection between the coolant pump and the radiator, and connection between the coolant tray and the radiator. Such an arrangement makes the assembling of the cooling device complicated for there are a great number of parts, including those pipes, which must be individually coupled to the coolant tray, the coolant pump, and the radiator. In addition, such a great number of the parts makes the cooling device expensive in manufacturing and bulky in size, which is against the trend of down-cost and miniaturization of the computer or electronic industry and is thus not suitable for applications in portable devices.
• Thus, the present invention is aimed to provide a coolant tray of a liquid based cooling device that overcomes, or at least alleviates, the above-discussed problems.
SUMMARY OF THE INVENTION
• A primary objective of the present invention is to provide a liquid based cooling device comprising a coolant tray, a pump, and a radiator, wherein the pump and the coolant tray are combined together as a single unitary device in order to simplify the structure and manufacturing of the liquid based cooling device.
• To achieve the above objective, in accordance with the present invention, a coolant tray for a liquid based cooling device is provided. The liquid based cooling device comprises a pump for driving a coolant through the coolant tray that is positionable on a heat generating device and a radiator that dissipates the heat into the surrounding. The coolant tray comprises a housing on which coolant inlet and outlet are formed for receiving the coolant from the pump and discharging the coolant to the radiator. The coolant tray also forms a recess in which a thermally conductive base forming a coolant channel is received in a liquid tight manner. The pump comprises a casing in which coolant inlet and outlet are formed. The inlet of the coolant tray is integrally connected to the outlet of the pump and the housing of the coolant tray and the casing of the pump are integrally formed with each other with an integrally formed conduit connected therebetween.
• Since three parts, including the housing of the coolant tray, the casing of the pump, and the conduit connected between the housing and the casing are integrally formed together with the same material as a single unitary member, the structure and manufacturing of the cooling device is simplified and the overall size reduced, making the cooling device in accordance with the present invention particularly suitable for portable electronic devices that have a very limited interior space for accommodation of the cooling device, while requiring efficient removal of heat.
BRIEF DESCRIPTION OF THE DRAWINGS
• The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, in which:
• FIG. 1 is a perspective view of a liquid based cooling device in which a coolant tray constructed in accordance with the present invention is incorporated;
• FIG. 2 is an exploded view of the coolant tray and a coolant pump in accordance with the present invention; and
• FIG. 3 is a cross-sectional view of a combined unitary device of the coolant tray and the coolant pump in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• With reference to the drawings and in particular toFIG. 1, a liquid based cooling device is shown. The cooling device is operated with a liquid coolant, such as water, for cooling for example anelectronic device29, such as a computer central processing unit mounted on acircuit board28 of the computer system (seeFIG. 3), which generates heat that must be removed to maintain the temperature of theelectronic device29 within a proper range. The cooling device is comprised of acoolant tray20 having a surface positionable on and in physical contact with theelectronic device29, aradiator30 spaced from thecoolant tray20 and located in a low temperature surrounding, and apump10 connected to theradiator30 and thecoolant tray20 by pipes to complete a circulation loop among thecoolant tray20, thepump10, and theradiator30. Thepump10 circulates a coolant between thecoolant tray20 and theradiator30. Heat carried by the coolant to theradiator30 is dissipated into the surrounding by natural convection and radiation. Preferably, afan40 is combined with theradiator30 to induce force convection for more efficiently dissipating the heat into the surrounding.
• Also referring toFIGS. 2 and 3, thepump10 comprises acasing11 defining anupper chamber12 delimited by a side wall (not labeled) forming anoutlet13. Theupper chamber12 is closed by alid16 in which aninlet17 is formed and in fluid communication with theupper chamber12. A blade assembly comprised of a plurality ofblades15 extending from a hub to which amagnet14 is attached. The blade assembly is rotatably fit over ashaft19 extending in theupper chamber12 to serve as a rotor of thepump10.
• Thecoolant tray20 constructed in accordance with the present invention comprises aflat housing21 having a top surface in which acoolant inlet24 and acoolant outlet25 are formed. Theflat housing11 has a bottom surface opposite to the top surface and defining a recess (not labeled and shown inFIG. 4) in which abase22 is received in a liquid-tight manner. Thebase22 is secured to thehousing21 by means offasteners26, such as bolts. Thebase22 is made of thermally conductive materials, such as metal, to enhance heat transfer between theheat generating device29 and the coolant.
• Thebase22 of thecoolant tray20 has a top received in the recess of thehousing21 and a bottom exposed for positionability on and tight contact with thecentral processing unit29. The positioning of thecoolant tray20 on thecentral processing unit29 can be secured by fasteners, such asbolts27, tightened on thecircuit board28.
• The top of thebase22 forms acoolant channel23 having opposite ends (not labeled) respectively corresponding in position to and in fluid communication with the inlet andoutlet24,25 of thehousing21 whereby the coolant flowing through theinlet24 is allowed to enter an end of thechannel23, and then flowing along thechannel23 toward the other end at which the coolant is allowed to discharge through theoutlet25.
• Thecoolant outlet25 of thecoolant tray20 is connected by apipe50 to theradiator30 where heat carried by the coolant is dissipated to the surrounding. The coolant flowing through theradiator30 is guided to thepump10 through thecoolant inlet17 that is connected to theradiator30. Apipe18 is connected between thecoolant outlet13 of thepump10 and thecoolant inlet24 of thecoolant tray20, guiding the coolant that is driven by thepump10, into thecoolant tray20.
• Thecoolant inlet24 of thecoolant tray20 is connected by thepipe18 to thecoolant outlet13 of theupper chamber12 of thepump10. Thepipe18 is integrated with thehousing21 of thecoolant tray20 and thecasing11 of thepump10. In other words, thehousing21 of thecoolant tray20, thepipe18, and thecasing11 of thepump10 are integrally formed together as a unitary member made with the same material. Thus, three parts, including thehousing21 of thecoolant tray20, thepipe18, and thecasing11 of thepump10, are combined together as a single unitary part. In addition, the couplings between thepipe18 and thecoolant inlet24 of thecoolant tray20 and between thepipe18 and thecoolant outlet13 of thepump10 are eliminated. Consequently, the number of parts of the cooling device is reduced to quite an extent and the manufacturing thereof is substantially simplified.
• In addition, due to the integration of thehousing21 of thecoolant tray20 and thecasing11 of thepump10, thepump10 and thecoolant tray20 are fixed with respect to each other and the spatial relationship is fixed. The distance between thepump10 and thecoolant tray20 can be minimized, whereby the amount of space occupied by the cooling device is minimized. This makes the cooling device a perfect choice for portable electronic devices that have a very limited interior space for accommodation of the cooling device.
• Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.

Claims (2)

1. In a liquid based cooling device comprising a pump for circulating a liquid coolant between a coolant tray that is positionable on a heat generating device to remove heat therefrom by the coolant flowing through the coolant tray and a radiator that dissipates heat carried by the coolant into the surrounding,

the pump comprising a casing forming a coolant outlet for guiding the coolant to the coolant tray; and

the coolant tray comprising a housing defining a recess receiving a thermally conductive base that defines a channel for the coolant, and the housing forming an inlet for receiving the coolant and an outlet through which the coolant flowing through the channel is discharged to the radiator;

wherein the inlet of the coolant tray is integrally connected to the outlet of the pump and the housing of the coolant tray and the casing of the pump are integrally formed with each other with an integrally formed conduit connected therebetween.

2. The coolant tray as claimed inclaim 1, wherein the housing, the casing, and the conduit are integrally formed with the same material.

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