Abstract: A rotary force transfer mechanism includes an input (e.g., a pedal or handle) that receives a substantially linear input force (e.g., from a human operator), a rotary structure (e.g., a gear), and a drive element for selective coupling with the rotary structure to transmit the input force to the rotary structure to cause a corresponding rotary motion of the rotary structure. When transmitting the input force to the rotary structure, the drive element engages with an outer circumferential surface of the rotary structure such that the input force is transmitted to the rotary structure in a direction tangential to a position where the drive element is coupled to the rotary structure.

Abstract: A method of operating variable pitch fans in series to cool an operating computer system. The method comprises running a first variable pitch fan with blades positioned at an operational pitch to induce airflow through the computer system and through a second variable pitch fan disposed in series with the first fan, and, simultaneously, not running the second variable pitch fan with blades positioned for minimal impedance to the airflow. In response to detecting a failure condition of the first fan, the method includes running the second fan with blades positioned at an operational pitch to induce airflow through the computer system and through the first fan, and, simultaneously, not running the first fan with blades positioned for minimal impedance to the airflow. Preferably, the method includes locking the rotor of a fan that is not running, and locking the blades of the non-running fan in a minimal impedance position.

Abstract: A computer system and method for measuring air density in a computer chassis. The computer chassis includes a fan, an ambient air temperature sensor, and a heat-generating device with a heat sink, a heat sink temperature sensor, and a controller. The controller controls the fan speed and applies a known amount of thermal energy to the heat sink, then determines the air density from the difference in temperature between the ambient air and the heat sink. The controller may then use the air density determination to adjust the air flow rate through the computer chassis to provide a proper air flow rate for cooling.

Abstract: A temperature isolation duct in a computer system comprising a chassis securing a circuit board and a fan system that draws air through the chassis, and a heat-generating component is mounted on the circuit board and exposed to the air flow. The hot air duct passively directs air heated by the heat-generating component from a single hot air duct inlet in direct downstream alignment with the heat-generating component to a single hot air duct outlet. A thermal sensor is secured within, or in direct alignment with, the hot air duct near the duct outlet for sensing the temperature of air flowing through the hot air duct and generating a temperature signal. A controller is in electronic communication with the thermal sensor for receiving the temperature signal and in electronic communication with the fan system for sending a fan speed control signal.

Abstract: A method of operating variable pitch fans in series to cool an operating computer system. The method comprises running a first variable pitch fan with blades positioned at an operational pitch to induce airflow through the computer system and through a second variable pitch fan disposed in series with the first fan, and, simultaneously, not running the second variable pitch fan with blades positioned for minimal impedance to the airflow. In response to detecting a failure condition of the first fan, the method includes running the second fan with blades positioned at an operational pitch to induce airflow through the computer system and through the first fan, and, simultaneously, not running the first fan with blades positioned for minimal impedance to the airflow. Preferably, the method includes locking the rotor of a fan that is not running, and locking the blades of the non-running fan in a minimal impedance position.

Abstract: A computer system and method for measuring air density in a computer chassis. The computer chassis includes a fan, an ambient air temperature sensor, and a heat-generating device with a heat sink, a heat sink temperature sensor, and a controller. The controller controls the fan speed and applies a known amount of thermal energy to the heat sink, then determines the air density from the difference in temperature between the ambient air and the heat sink. The controller may then use the air density determination to adjust the air flow rate through the computer chassis to provide a proper air flow rate for cooling.

Abstract: A temperature isolation duct in a computer system comprising a chassis securing a circuit board and a fan system, wherein the fan system draws air through the chassis in an airflow direction, and a heat-generating component is mounted on the circuit board and exposed to the air flow. The hot air duct passively directs air heated by the heat-generating component from a single hot air duct inlet in direct downstream alignment with the heat-generating component to a single hot air duct outlet, wherein the hot air duct has a length to width aspect ratio of greater than four. A first thermal sensor is secured within, or direct alignment with, the hot air duct near the duct outlet for sensing the temperature of air flowing through the hot air duct and generating a first temperature signal. A controller is in electronic communication with the first thermal sensor for receiving the temperature signal and in electronic communication with the fan system for sending a fan speed control signal.

Abstract: Systems and methods provide altitude-dependent fan control for a plurality of electronic subsystems using a shared air pressure sensor. Each server or multi-server chassis of a rack system is a subsystem of the rack system. Each subsystem receives its own on-board fan or blower module. The shared air pressure sensor senses air pressure and outputs a signal to all of the subsystems. Each subsystem then independently regulates its own fan speed according to the signal output by the shared air pressure sensor. Other fan operational parameters, such as the number of fans recruited, may also be controlled according to altitude according to the invention. A variety of other performance parameters, such as internal air or component temperature, ambient air temperature, server workload, and processor activity level, may also be factored into control of these fan operational parameters.

Abstract: A fan sink that includes a dual impeller push-pull axial fan and a heat sink to cool a hot electronic device is presented. The axial fan has a hub motor, a first impeller that is radially proximate to the hub motor, and a second impeller that is radially distal to the hub motor, wherein the first impeller pushes air in a first direction and the second impeller pulls air in a second direction. The heat sink is oriented between the axial fan and the hot electronic device such that the hot electronic device, the heat sink, and the axial fan are axially oriented, wherein cool air is forced onto the heat sink by one impeller in the axial fan, and wherein heated air from the heat sink is removed by an other impeller in the axial fan.

Abstract: A fan sink that includes a dual impeller push-pull axial fan and a heat sink to cool a hot electronic device is presented. The axial fan has a hub motor, a first impeller that is radially proximate to the hub motor, and a second impeller that is radially distal to the hub motor, wherein the first impeller pushes air in a first direction and the second impeller pulls air in a second direction. The heat sink is oriented between the axial fan and the hot electronic device such that the hot electronic device, the heat sink, and the axial fan are axially oriented, wherein cool air is forced onto the heat sink by one impeller in the axial fan, and wherein heated air from the heat sink is removed by an other impeller in the axial fan.

Abstract: A fan sink that includes a dual impeller push-pull axial fan and a heat sink to cool a hot electronic device is presented. The axial fan has a hub motor, a first impeller that is radially proximate to the hub motor, and a second impeller that is radially distal to the hub motor, wherein the first impeller pushes air in a first direction and the second impeller pulls air in a second direction. The heat sink is oriented between the axial fan and the hot electronic device such that the hot electronic device, the heat sink, and the axial fan are axially oriented, wherein cool air is forced onto the heat sink by one impeller in the axial fan, and wherein heated air from the heat sink is removed by an other impeller in the axial fan.

Abstract: A fan sink that includes a dual impeller push-pull axial fan and a heat sink to cool a hot electronic device is presented. The axial fan has a hub motor, a first impeller that is radially proximate to the hub motor, and a second impeller that is radially distal to the hub motor, wherein the first impeller pushes air in a first direction and the second impeller pulls air in a second direction. The heat sink is oriented between the axial fan and the hot electronic device such that the hot electronic device, the heat sink, and the axial fan are axially oriented, wherein cool air is forced onto the heat sink by one impeller in the axial fan, and wherein heated air from the heat sink is removed by an other impeller in the axial fan.

Abstract: An improved cooling system for a computer is disclosed. In one embodiment, the improved cooling system includes an angled blower housing and a frusto-conical, centrifugal impeller. The computer chassis has a chassis air inlet and a chassis air outlet. A blower housing is disposed in the computer chassis. The blower housing has a blower inlet face spaced within 0.512 inches (1.3 cm) from a wall of the computer chassis and facing the wall. A blower air inlet is disposed on the blower inlet face and a blower air outlet is in communication with the chassis air outlet. A centrifugal impeller is rotatably supported in the blower housing about an axis of rotation to move air from the blower air inlet to the blower air outlet. The centrifugal impeller defines a generally frusto-conical profile when rotated about the axis of rotation.

Abstract: A fan sink that includes a dual impeller push-pull axial fan and a heat sink to cool a hot electronic device is presented. The axial fan has a hub motor, a first impeller that is radially proximate to the hub motor, and a second impeller that is radially distal to the hub motor, wherein the first impeller pushes air in a first direction and the second impeller pulls air in a second direction. The heat sink is oriented between the axial fan and the hot electronic device such that the hot electronic device, the heat sink, and the axial fan are axially oriented, wherein cool air is forced onto the heat sink by one impeller in the axial fan, and wherein heated air from the heat sink is removed by an other impeller in the axial fan.

Abstract: A fan sink that includes a dual impeller push-pull axial fan and a heat sink to cool a hot electronic device is presented. The axial fan has a hub motor, a first impeller that is radially proximate to the hub motor, and a second impeller that is radially distal to the hub motor, wherein the first impeller pushes air in a first direction and the second impeller pulls air in a second direction. The heat sink is oriented between the axial fan and the hot electronic device such that the hot electronic device, the heat sink, and the axial fan are axially oriented, wherein cool air is forced onto the heat sink by one impeller in the axial fan, and wherein heated air from the heat sink is removed by an other impeller in the axial fan.

Abstract: A h9eat sink device for conventional memory modules, such as DIMMs, that is configured to be positioned between adjacent memory modules mounted in substantially parallel connectors on a printed circuit board. Each heat sink device includes thermally conductive first and second members configured to thermally couple with electronic components of a conventional memory module. The first and second members may be resiliently biased away from one another so that the resilient bias causes the members to abut respective electronic components when placed between adjacent memory modules. A separate wedge, or a lever-mounted wedge, may be provided for insertion between the members to urge them away from one another and into abutting relationship with electronic components on facing surfaces of the adjacent memory modules. When abutting opposing electronic components, a single heat sink device facilitates heat dissipation from both of the adjacent memory modules.

Abstract: A structure for cooling an electronic component includes a heat sink attached to the component, an inner air duct extending into a central portion of the heat sink, and an outer air duct extending into an outer portion of the heat sink. In inner fan, within the inner air duct, moves air in one direction, while an outer fan, in the outer air duct, moves air in the other direction. The fans may be built as separate rotors, or as separate portions of a single rotor.

Abstract: A heat sink having graduated lengths of fins, with the tallest fins being in the center of the heat sink to provide maximum heat removal from a mated integrated circuit (IC) chip. Dual fans impinge air against the fins, and particularly the tallest fins, to provide a highly efficient system for heat removal from the IC chip. By reducing the size of the lateral fins, additional space is made available for the dual fans. The use of the dual fans allows the fans to run at a lower speed that a single fan, thus reducing an overall fan acoustic level. Furthermore, the dual fans allow for a backup fan system if one of the fans should fail.

Abstract: A heat sink having an air flow director on each of multiple fins attached to a heat sink base. The air flow directors direct most of the air flow from dual push-pull fans towards a midline and a geometric center of the heat sink base, which is above the hottest part of the integrated circuit (IC) package being cooled by the heat sink. The rest of the air flow from the push-pull fans impinges against the air flow directors, providing additional cooling to the fins.

Abstract: A heat sink having air flow directors on each of multiple fins attached to a heat sink base. The air flow directors direct air flow from dual fans towards a geometric center of the heat sink base, which is above the hottest part of the integrated circuit (IC) package being cooled by the heat sink. In one embodiment, a protrusion in the geometric center of the heat sink base provides additional cooling from air impingement, and also directs air towards the upper portions of the fins. The use of dual fans allows the fans to run at a lower speed than a single fan, thus reducing an overall fan acoustic level. Furthermore, the dual fans allow for a backup fan if one of the fans should fail.