Abstract: Fan assemblies are disclosed. Fan assemblies include an impeller with asymmetric design. For example, an impeller may include a first set of blades with one geometry and second set of fan blades with another geometry. This enables a dual-inlet centrifugal fan to generate different air flow performance characteristics for the air entering one fan inlet compared to the air entering the other fan inlet. The impeller, with different fan blade configurations, can better handle air flow entering the fan assembly through different inlets, particularly when the air flow conditions differ through the inlets due to impeding structures (e.g., motor, struts, etc.). As a result, air flow distribution from air leaving the impeller, including the locations associated with the different fan blade configurations, is relatively uniform. Beneficially, when air flow distribution uniformity increases, the fan assembly operates more efficiently, as air flow pressure losses due to flow separation are mitigated.

Abstract: A fan assembly having a reduced dimension formed by several modifications is described. The fan assembly includes a stator having stator coils positioned within a recessed portion of a pillow that receives the motor. The stator may include wire connections positioned between adjacent stator coils and designed to terminate wires of the stator coils. The wire terminations may be on a protrusion or a post positioned between adjacent stator coils, or alternatively, the wire terminations may be disposed on protruding features of a bushing. The protrusion may be formed from an electrically conductive material and electrically connected to a motor control circuit via a flexible printed circuit. In some embodiments, the protrusion is part of an electrically neutral stator bushing having several pins. Also, a gap region between the bushing and a flange feature is designed to improve an adhesive joint.

Abstract: Fan assemblies are disclosed. Fan assemblies include an impeller with asymmetric design. For example, an impeller may include a first set of blades with one geometry and second set of fan blades with another geometry. This enables a dual-inlet centrifugal fan to generate different air flow performance characteristics for the air entering one fan inlet compared to the air entering the other fan inlet. The impeller, with different fan blade configurations, can better handle air flow entering the fan assembly through different inlets, particularly when the air flow conditions differ through the inlets due to impeding structures (e.g., motor, struts, etc.). As a result, air flow distribution from air leaving the impeller, including the locations associated with the different fan blade configurations, is relatively uniform. Beneficially, when air flow distribution uniformity increases, the fan assembly operates more efficiently, as air flow pressure losses due to flow separation are mitigated.

Abstract: An electronic device includes a fan assembly that draws air (including heated air) away from components and forces the air out of the electronic device. The fan assembly includes a guide vane located in the fan housing. Subsequent to air entering the fan assembly via the fan inlets, the guide vane is designed to direct the air to a fan outlet. Further, the guide vane is designed and positioned in the fan assembly to limit or prevent flow separation that may cause the heated air to recirculate and may also cause increased turbulence leading to elevated acoustic noise. Furthermore, the guide vane may include a tapered region to allow the heated air to readily flow over the guide vane to limit or prevent a vortex from occurring within the fan assembly. Using the guide vane, the fan assembly drives more air at the same fan speed and lowers noise generation.

Abstract: A cooling system for optimizing fan air flow performance without compromising acoustic performance is disclosed. At least three fan feature embodiments are disclosed: (1) sloped fan blades, (2) sloped impeller hubs, and (3) inlet flow guidance features. For the first embodiment, fan blades attached to an impeller disc and having leading edges that progressively curve toward a center of the impeller disc. For the second embodiment, the impeller disc is attached to and centered on an impeller hub that has a sloped hub surface that progressively curves toward the fan blades. For the third embodiment, an inlet flow guidance feature is positioned within a region surrounding a fan's inlet promoting smooth passage of air into the fan. In some embodiments, all three fan features are combined.

Abstract: A fan assembly having a reduced dimension formed by several modifications is described. The fan assembly includes a stator having stator coils positioned within a recessed portion of a pillow that receives the motor. The stator may include wire connections positioned between adjacent stator coils and designed to terminate wires of the stator coils. The wire terminations may be on a protrusion or a post positioned between adjacent stator coils, or alternatively, the wire terminations may be disposed on protruding features of a bushing. The protrusion may be formed from an electrically conductive material and electrically connected to a motor control circuit via a flexible printed circuit. In some embodiments, the protrusion is part of an electrically neutral stator bushing having several pins. Also, a gap region between the bushing and a flange feature is designed to improve an adhesive joint.

Abstract: An electronic device includes a fan assembly that draws air (including heated air) away from components and forces the air out of the electronic device. The fan assembly includes a guide vane located in the fan housing. Subsequent to air entering the fan assembly via the fan inlets, the guide vane is designed to direct the air to a fan outlet. Further, the guide vane is designed and positioned in the fan assembly to limit or prevent flow separation that may cause the heated air to recirculate and may also cause increased turbulence leading to elevated acoustic noise. Furthermore, the guide vane may include a tapered region to allow the heated air to readily flow over the guide vane to limit or prevent a vortex from occurring within the fan assembly. Using the guide vane, the fan assembly drives more air at the same fan speed and lowers noise generation.

Abstract: A cooling system for optimizing fan air flow performance without compromising acoustic performance is disclosed. At least three fan feature embodiments are disclosed: (1) sloped fan blades, (2) sloped impeller hubs, and (3) inlet flow guidance features. For the first embodiment, fan blades attached to an impeller disc and having leading edges that progressively curve toward a center of the impeller disc. For the second embodiment, the impeller disc is attached to and centered on an impeller hub that has a sloped hub surface that progressively curves toward the fan blades. For the third embodiment, an inlet flow guidance feature is positioned within a region surrounding a fan's inlet promoting smooth passage of air into the fan. In some embodiments, all three fan features are combined.

Abstract: The described embodiments relate to improving efficiency of a low-profile cooling fan. In one embodiment, an impeller of the cooling fan includes a shroud which covers a central portion of the impeller, thereby allowing a central inlet portion of the blades to have an increased fan blade height when compared to a cooling fan constrained by minimum part tolerances between the fan blades and a portion of the fan housing. In some embodiments, the impeller includes splitter blades that can improve performance of the low-profile cooling fan.

Abstract: A thermal management system that includes a fan assembly, a heat exchanger, and an insulating box is described. The fan assembly can have two impellers and a housing that includes two scroll portions. An internal portion of the scroll wall can be truncated. A motor housing can be connected to the fan housing via multiple struts. The struts can be oriented angularly with a tangential component and can slope inward to increase the effective inlet area. The heat exchanger can be formed of a fin stack that has a curved body that defines an airflow path that turns radially from the inlet to the exhaust. The heat exchanger can have an inlet that is smaller than the exhaust. The heat exchanger can be connected to one or more heat pipes. The insulating box can have a grid that directs air to certain specific directions.

Abstract: A cooling system for optimizing fan air flow performance without compromising acoustic performance is disclosed. At least three fan feature embodiments are disclosed: (1) sloped fan blades, (2) sloped impeller hubs, and (3) inlet flow guidance features. For the first embodiment, fan blades attached to an impeller disc and having leading edges that progressively curve toward a center of the impeller disc. For the second embodiment, the impeller disc is attached to and centered on an impeller hub that has a sloped hub surface that progressively curves toward the fan blades. For the third embodiment, an inlet flow guidance feature is positioned within a region surrounding a fan's inlet promoting smooth passage of air into the fan. In some embodiments, all three fan features are combined.

Abstract: A thermal management system that includes a fan assembly, a heat exchanger, and an insulating box is described. The fan assembly can have two impellers and a housing that includes two scroll portions. An internal portion of the scroll wall can be truncated. A motor housing can be connected to the fan housing via multiple struts. The struts can be oriented angularly with a tangential component and can slope inward to increase the effective inlet area. The heat exchanger can be formed of a fin stack that has a curved body that defines an airflow path that turns radially from the inlet to the exhaust. The heat exchanger can have an inlet that is smaller than the exhaust. The heat exchanger can be connected to one or more heat pipes. The insulating box can have a grid that directs air to certain specific directions.

Abstract: The described embodiments relate to improving efficiency of a low-profile cooling fan. In one embodiment, an impeller of the cooling fan includes a shroud which covers a central portion of the impeller, thereby allowing a central inlet portion of the blades to have an increased fan blade height when compared to a cooling fan constrained by minimum part tolerances between the fan blades and a portion of the fan housing. In some embodiments, the impeller includes splitter blades that can improve performance of the low-profile cooling fan.

Abstract: A method to reduce acoustic noise in a cooling fan motor is disclosed. The method includes reducing the slew rate of a PWM (pulse width modulation) voltage waveform applied to energize a coil of the fan motor. This slew rate reduction results in lower mechanical vibrations and acoustic noise in the fan motor. In one embodiment, the slew rate reduction is performed during startup of the fan motor, when the motor is spinning slowly and there is little air flow noise. In another embodiment, the slew rate reduction is not performed during high speed operation of the fan motor, when the fan motor is spinning very fast and air flow noise masks the motor noise. In one embodiment, there is variable slew rate control depending on the speed of the fan motor.

Abstract: A fan assembly having a reduced dimension formed by several modifications is described. The fan assembly includes a stator having stator coils positioned within a recessed portion of a pillow that receives the motor. The stator may include wire connections positioned between adjacent stator coils and designed to terminate wires of the stator coils. The wire terminations may be on a protrusion or a post positioned between adjacent stator coils, or alternatively, the wire terminations may be disposed on protruding features of a bushing. The protrusion may be formed from an electrically conductive material and electrically connected to a motor control circuit via a flexible printed circuit. In some embodiments, the protrusion is part of an electrically neutral stator bushing having several pins. Also, a gap region between the bushing and a flange feature is designed to improve an adhesive joint.

Abstract: The described embodiments relate to improving efficiency of a low-profile cooling fan. In one embodiment, an impeller of the cooling fan includes a shroud which covers a central portion of the impeller, thereby allowing a central inlet portion of the blades to have an increased fan blade height when compared to a cooling fan constrained by minimum part tolerances between the fan blades and a portion of the fan housing. In some embodiments, the impeller includes splitter blades that can improve performance of the low-profile cooling fan.

Abstract: A fluid dynamic bearing motor and method are provided for use with various disc drive memory device products differently rated by operational rotational speed. The operational speeds are those speeds measured during reading and writing memory operations to the memory device. In an aspect, the present invention meets full operating requirements, including stiffness and power requirements, at multiple rated speeds for use with either standard or high-end performance disc drive products. Costs associated with a dedicated manufacturing line for high-end products are substantially reduced. A single manufacturing line can serve both standard and high-end disc drive memory device products. The present invention is especially useful in reducing costs of 2.5 inch notebook products that are typically marketed in two levels of performance, namely, 5400 RPM standard performance products and 7200 RPM high performance products.

Abstract: A fan assembly for a computing device is disclosed. The fan assembly can include an impeller having a number of blades and a motor for turning the blades. The motor can turn the blades via a magnetic interaction between the impeller and the motor. A fluid dynamic thrust bearing can be used to control a position of the impeller relative to the motor. In particular, the impeller can be configured to rotate around an axis and the thrust bearing can be used to control movement of the impeller in a direction aligned with the rotational axis. In one embodiment, the thrust bearing can be configured to stabilize the impeller when vibratory forces act upon the fan assembly. More particularly, parameters associated with the thrust bearing can be selected to counteract vibratory forces emitted by a speaker system.

Abstract: The described embodiments relate generally to improving performance characteristics of a low profile fan. More specifically configurations having sloped fan blade edges are disclosed. By applying a gradual slope to each of the fan blades, performance of the fan can be increased without risking contact or rubbing between the fan blades and a fan housing. In some embodiments, the sloped fan blades can be configured to prevent contact when bearings of the fan include a certain amount of tilt play.

Abstract: A fan assembly having a reduced dimension formed by several modifications is described. The fan assembly includes a stator having stator coils positioned within a recessed portion of a pillow that receives the motor. The stator may include wire connections positioned between adjacent stator coils and designed to terminate wires of the stator coils. The wire terminations may be on a protrusion or a post positioned between adjacent stator coils, or alternatively, the wire terminations may be disposed on protruding features of a bushing. The protrusion may be formed from an electrically conductive material and electrically connected to a motor control circuit via a flexible printed circuit. In some embodiments, the protrusion is part of an electrically neutral stator bushing having several pins. Also, a gap region between the bushing and a flange feature is designed to improve an adhesive joint.