There are a variety of rack mount enclosures currently available which draw external ambient air from the front of the enclosure, pass the air through the enclosure and exhaust the air through the rear of the enclosure. As the moving air passes by operating circuits within the enclosure, the air carries away heat from the operating circuits thus maintaining the operating circuits within a normal operating temperature range for proper operation and reliability.
One conventional rack mount enclosure is 1 U (approximately 1.75 inches) in height and includes a fan assembly configured as a field replaceable unit (FRU). The fan assembly includes a fan frame and a row of four fans fastened to the fan frame. The fan frame includes a vertical face plate which faces outwardly from the front of the enclosure and two thumbscrews secured to the vertical face plate. The vertical face plate and the thumbscrews are offset from the profiles of the four fans in order to avoid obstructing the airflow generated by the fans. The thumbscrews thread into thumbscrew holes defined by the enclosure thus holding the frame to the enclosure to prevent the fan assembly from inadvertently escaping (e.g., due to vibration).
Suppose that an installed fan assembly suffers a fan failure while out in the field. To replace the installed fan assembly with a new fan assembly, a field technician unscrews the thumbscrews from the enclosure and pulls the installed fan assembly out of the enclosure. The field technician then slides the new fan assembly into the enclosure and screws the thumbscrews of the new fan assembly into the enclosure. If such fan assembly replacement occurs within a short amount of time (e.g., 30 seconds), the temperature of the operating circuits within the enclosure will remain within the normal operating temperature range thus alleviating the need to turn off the operating circuits to prevent overheating during fan assembly replacement.
The foregoing and other objects, features and advantages will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the invention.
Unfortunately, there are deficiencies with the above-described conventional 1U rack mount enclosure which uses a fan assembly FRU having a fan frame and a row of four fastened fans. For example, the offset vertical face plate of the fan frame obstructs a significant amount of front opening area that could otherwise be used for additional air exhaust out of the enclosure. As a result, the conventional fan assembly FRU uses fans with larger capacity (to move more air) than would otherwise be needed if the front opening were larger. The use of such larger capacity fans imposes several other related burdens as well (e.g., the need for larger fan motors for more powerful air movement, larger power consumption and thus the potential need for larger power supplies, and so on).
Furthermore, the frame configuration of the above-described conventional fan assembly FRU requires that all four of the fans be replaced at the same time since all of the fans are fastened to the fan frame. Accordingly, even if only one fan fails, the entire fan assembly FRU must be replaced which is wasteful. Moreover, the field technician has the burden of carrying out the replacement in a very short amount of time (e.g., 30 seconds) or risks causing an emergency system shutdown due to overheating of the operating circuits within the enclosure while all of the fans are removed.
In contrast to the above-described conventional 1U rack mount enclosure which uses a fan assembly FRU having an obstructing vertical face plate and a row of four fans, embodiments of the invention involve the use of a field replaceable fan device having a fan and an attachment assembly which is disposed in front of the fan, but in a non-obstructing manner that does not block the fan. That is, the fan sits between the electronic circuitry being cooled and the attachment assembly which controls attachment of the fan device so that the attachment assembly resides within the profile of the fan, i.e., the attachment assembly has a width which is at most equal to a width of the fan profile. Accordingly, multiple fans are capable of being installed individually, and are further capable of being replaced individually without interfering with the operation of the other fans or the electronic circuitry.
One embodiment is directed to a fan device which includes a connector, a fan, and an attachment assembly. The fan is configured to provide cooling to electronic circuitry when the fan receives a power signal through the connector. The attachment assembly is configured to control attachment of the fan device to a chassis within an air duct defined by the chassis. The fan defines (i) a near side which faces the electronic circuitry, (ii) a far side which faces away from the electronic circuitry, (iii) an airflow axis which extends from the near side to the far side along an airflow direction, and (iv) a fan profile which is substantially perpendicular to the airflow axis. The fan is disposed substantially between the electronic circuitry and the attachment assembly when the fan device attaches to the chassis within the air duct. The attachment assembly has a width which closely mirrors that of the fan profile.
As shown in
During operation, both the electronic circuitry 30 and the fan devices 32 preferably draw power from the power sources 28. The electronic circuitry 30 performs electronic operations (e.g., data communications operations, data processing operations, etc.) and the fan devices 32 provide cooling to the electronic circuitry 30. By way of example, the fan devices 32 (i) draw external ambient air from a front 36 of the electronic equipment rack 26 through a central core 38 of the chassis 22, and (ii) exhaust the air out to a back 40 of the electronic equipment rack 26 for robust and reliable removal of heat from the electronic circuitry 30 (illustrated by the arrow 42 which is substantially parallel to the Z-axis in
As will be explained in further detail shortly, a user is capable of removing each fan device 32 individually by actuating a portion of the front of the fan device 32. With removal of only one fan device 32 at a time, the user is capable of replacing any fan device 32 which fails while allowing the other fan devices 32 to remain installed and in operation. As a result, replacement of a failed fan device 32 is less expensive than replacing a conventional four fan assembly, and is capable of being performed without risk of overheating the electronic circuitry 30 since the remaining fan devices 32 can continue to provide cooling during replacement of the failed fan device 32.
Moreover, since there is no obstructing vertical face plate as in conventional fan assemblies, the profiles of the fan devices 32 (i.e., the geometry of the fan devices in the X-Y plane of
The electrical connector 62 is constructed and arranged to mechanically connect with the electronic circuitry 30 and electrically connect to the power sources 28 through the electronic circuitry 30 to obtain a power signal (also see
The base portion 70(C) includes an attachment assembly 72 which is constructed and arranged to control attachment of the fan device 32 to the chassis 22. As will be described in further detail shortly, the attachment assembly 72 is configured to actuate parts of the EMI shield 66 which control latching of the fan device 32 to the chassis 32 and unlatching of the fan device 32 from the chassis 32.
It should be understood that the fan 64 has a face or fan profile 74 which essentially determines the necessary size of the fan device 32, i.e., the outer dimensions of the fan 64 in the X-Y plane. Both the EMI shield 66 and the attachment assembly 72 reside substantially in front of this fan profile 74 but nevertheless possess geometries to allow robust air flow (see
The attachment assembly 72 has a width W(A) which closely mirrors a width W(F) of the fan profile 74. In some arrangements, the attachment assembly width W(A) exceeds the fan profile width W(F) by only a few mils (e.g., 0.010 inches or less) thus minimizing consumption of area in the X-Y which is now available for air flow. That is, due to the geometry of the attachment assembly 72, the attachment assembly 72 sits directly in front of the fan 64 (i.e., within the fan profile 74) thus enabling the fan device 32 to efficiently utilize the amount of available opening to the chassis core 38. In contrast to conventional devices which require a face plate and thumbscrew to fasten a fan assembly to an enclosure, the attachment assembly 72 does not need any face plate or any thumbscrew that could otherwise obstruct air flow or otherwise reduce the size of the chassis openings for sub-optimal air flow. Further details will now be provided with reference to
In some arrangements, the EMI shield 66 is formed from a single section of thin sheet metal which is cut and folded into the form illustrated in
As further shown in
With attention now drawn to the removed fan device 32 of
As illustrated in
It should be understood that, during fan device insertion, the electrical connector 62 of the fan device 32 connects with an edge portion 110 of the electronic circuitry 30 in a blind mating manner. As will be described in further detail shortly, the edge portion 110 may define a slot 112 if the electronic circuitry 30 is implemented as a circuit board with a particular thickness.
To remove a fan device 32 from a duct 34, the user simply actuates the levers 104 of the actuation assembly 72. In particular, the user applies actuation force to the levers by squeezing the levers 104(R), 104(L) toward each other thus overcoming the spring forces of the tab portions 82(L) and deflecting the tab portions 82(L) toward each other and away from the duct walls 110. The narrowing shape and curvature of the lever guide 102 provides interference against the levers 104 to prevent over-travel of the levers 104 and thus prevent damage to either the levers 104 or the EMI shield 66. In response to disengagement of the catches 92 from the duct walls 110, the fan device is no longer locked onto the chassis 22 and user is able to freely extract the fan device 32 by moving the fan device 32 out of the duct 34 in the positive Z-direction. Further details will now be provided with reference to
As best illustrated in
As shown in
As shown in
It should be understood that, due to the ability of the fan device 32 to connect with circuit boards of different thicknesses, the fan device 32 is capable of connecting to different designed circuit boards. For instance, for circuit boards having less layers, the electrical connector 62 is capable of making competent edge connections (
By way of example, the component 200 is shown in
Due to the ability of the fan device 32 to connect to circuit boards of various thicknesses, and to non-system-level equipment, the fan device 32 is capable of being used in a variety of applications. Such a fan device 32 enables the manufacturer to re-use the fan device 32 in different applications with little or no re-design.
While various embodiments of the invention have been particularly shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
For example, the fan devices 32 were described above as drawing air through the central core 38 of the chassis 22 and exhausting the air out a back 40 of the chassis 22 (i.e., in the positive Z-direction) by way of example only. In other arrangements, the fan devices 32 blow air into the central core 38 in the opposite direction to provide cooling (i.e., in the negative Z-direction). Such other arrangements may be desirable when the fan devices 32 reside at a front of an enclosure so that the warmed air is exhausted out a rear of the enclosure and generally away from any equipment operators or technicians.
Additionally, it should be understood that the electrical connectors 62 of the fan devices 32 were shown as having contacts 122 on only one side by way of example only. In other arrangements, the electrical connectors 62 have contacts 122 on multiple sides, e.g., upper and lower sides, to provide additional exchange of signals therebetween. Such modifications and enhancements are intended to belong to various embodiments of the invention.
Number | Name | Date | Kind |
---|---|---|---|
5562410 | Sachs et al. | Oct 1996 | A |
6611427 | Liao | Aug 2003 | B1 |
6616525 | Giraldo et al. | Sep 2003 | B1 |
6625019 | Steinman et al. | Sep 2003 | B1 |
6646877 | Willers et al. | Nov 2003 | B2 |
6663416 | Huang et al. | Dec 2003 | B2 |
6690576 | Clements et al. | Feb 2004 | B2 |
6700779 | Hanson et al. | Mar 2004 | B2 |
6768640 | Doblar et al. | Jul 2004 | B2 |
6795314 | Arbogast et al. | Sep 2004 | B1 |
6808411 | Chen | Oct 2004 | B2 |
6865078 | Chang | Mar 2005 | B1 |
6896611 | Giraldo et al. | May 2005 | B2 |
7009841 | Chen et al. | Mar 2006 | B2 |
7021895 | Rubenstein et al. | Apr 2006 | B2 |
7033206 | Chang et al. | Apr 2006 | B2 |
7054155 | Mease et al. | May 2006 | B1 |
7173822 | Liang et al. | Feb 2007 | B2 |
7239528 | McLeod | Jul 2007 | B1 |
7251135 | Crippen et al. | Jul 2007 | B2 |
7253743 | Liang et al. | Aug 2007 | B2 |
7262962 | McLeod et al. | Aug 2007 | B1 |