Patent ID: 8622176
Filing Date: 2014-01-07
Classification: B64D,F16H,Y10T

Abstract:
1. A gearbox for use in an auxiliary power unit comprising: a plurality of gears and bearings received within a housing; a lube pump mounted within said housing, said lube pump configured to deliver oil to said plurality of gears and bearings, said lube pump including an inlet tube for supplying oil to said lube pump for delivery to said plurality of gears and bearings; an oil reservoir configured to maintain a quantity of oil above a lowermost end of said inlet tube, said oil reservoir shaped such that a first flow cross-sectional area at a lower end of said inlet tube includes a first cross-sectional area, and said oil reservoir defining a second cross-sectional area upwardly from said first cross-sectional, the second cross-sectional area comprising a greater cross-sectional area than the first cross-section, with a ratio of said second cross-sectional area to said first cross-sectional area less than 3; said oil reservoir including sides defined on lateral sides of a rotational axis of said lube pump, said lateral sides ramping toward each other from upper locations toward said first cross-sectional area, to result, in part, in the difference between said first and second cross-sectional areas; said oil reservoir including enlarged portions extending away from a nominal face of said oil reservoir for a first distance in a direction measured along said rotational axis, with said enlarged portions ramping inwardly to a smaller portion spaced by a lesser second distance from said nominal face at locations closer to a location of said first cross-sectional area, to further result, in part, in the difference between said first and second cross-sectional areas; wherein a ratio of a distance from a forward face of said gearbox to a rear face of said enlarged portions relative to a distance from said forward face to a rear face of said smaller portion is between 0.8 and 0.9; wherein said enlarged portions on said rear face are separated by a channel on an outside wall of the housing; and wherein at least one of said enlarged portions extends around to an enlarged side on a lateral side of said oil reservoir, said enlarged side being enlarged relative to a nominal side surface, and extending toward, but not reaching, said forward face.