Air bearing heat exchanger
The various technologies presented herein relate to fabrication and operation of a heat exchanger that is configured to extract heat from an underlying substrate. Heat can be extracted by way of an air gap formed between an impeller and a baseplate. By utilizing a pump to create an initial air gap that is further maintained by rotation of the impeller relative to the baseplate, a spring can be utilized that can apply a force of greater magnitude to the impeller than is used in a conventional approach, thus enabling the weight of the impeller to be negligible with respect to a width of the air gap, thereby conferring the desirable feature of orientation independence with respect to gravity with no performance degradation.
1. A heat exchanger comprising:
a baseplate that comprises:
a shaft that extends orthogonally from an upper surface of the baseplate at a center of the baseplate; and
a channel that extends from an outer surface of the baseplate to the upper surface of the baseplate;
a heat sink impeller (HSI) that comprises:
a first surface that faces the upper surface of the baseplate, the first surface has an area A base ;
a second surface opposite the first surface;
a plurality of vanes that extend from the second surface;
an aperture at a center of the HSI, wherein the shaft extends through the aperture and the HSI is rotatable about the shaft, a compressive spring is placed on the shaft and applies a force F spring on the HSI towards the baseplate, the HSI has a weight, and further wherein F spring is greater than the weight of the HSI; and
a pump, wherein the pump is connected to the channel at the outer surface of the baseplate, the pump is configured to generate a first air flow to create an air bearing between the HSI and the baseplate with a width G and an average pressure P air bearing acting on the first surface of the HSI, wherein P air bearing A base exceeds the weight of the HSI and acts in opposition to F spring , the magnitudes of P air bearing A base and F spring exceed the weight of the HSI.
2. The heat exchanger of claim 1 , further comprising a motor that causes the HSI to rotate about the shaft, wherein rotation of the HSI relative to the baseplate creates a force that acts in opposition to F spring .
3. The heat exchanger of claim 1 , wherein the HSI comprises a sealing cap that defines a cavity, wherein the shaft is positioned within the cavity.
4. The heat exchanger of claim 1 , wherein F spring is at least twenty times the weight of the HSI.
5. The heat exchanger of claim 1 , wherein P air bearing A base is at least twenty times the weight of the HSI.
6. The heat exchanger of claim 1 , wherein a nut is fastened to an upper portion of the shaft, and further wherein F spring is adjusted by alteration of a position of the nut along the shaft.
7. The heat exchanger of claim 1 , wherein the first air flow creates a hydrostatic bearing between the HSI and the baseplate, and a second air flow caused by rotation of the HSI relative to the baseplate creates a hydrodynamic bearing between the HSI and the baseplate.
8. The heat exchanger of claim 1 , further comprising a sensor that is configured to output a signal that is indicative of a distance between the upper surface of the baseplate and the first surface of the HSI.
9. The heat exchanger of claim 8 , further comprising a controller configured to:
receive the signal output by the sensor; and
control operation of the pump to change the magnitude of P air bearing A base to adjust the width G of the air bearing.