Lightweight torque transmission gear

A computer implemented method for designing a torque transmitting structure, comprising:

• inputting a finite element model of an initial structural design via a user interface;
• defining design and non-design space on the initial structural design;
• setting up topology optimization parameters;
• iteratively optimizing topology variations from the initial structural design by varying the topology optimization parameters in a computer simulator running a computer simulation until topology optimization criteria are satisfied to generate a topology optimized design;
• storing the topology optimized design in a first three dimensional modeling format;
• iteratively optimizing geometry variations from the topology optimized design by varying geometric optimization parameters of each geometry design iteration in the computer simulator running the computer simulation and evaluating geometry optimization criteria until geometry optimization targets are satisfied to generate a geometry optimized design;
• storing the geometry optimized design in a second three dimensional modeling format;
• and
• generating a hardware prototype according to the geometry optimized design.

A gear for transmitting torque, comprising:

• a steel toothed annular flange having gear teeth defined on a periphery thereof;
• a steel hub coaxially aligned with the steel toothed annular flange;
• a web formed from a web material having a density less than or equal to 3.0 grams per cubic centimeter (g/cm3), the web fixedly attached to the steel toothed annular flange and to the steel hub for rotation therewith;
• a plurality of first lugs defined at spaced intervals on an interior surface of the steel toothed annular flange;
• a plurality of first grooves defined in an outer web circumferential surface wherein the plurality of the first grooves is complementary to the plurality of the first lugs, and wherein a total quantity of the first grooves is at least equal to a total quantity of the first lugs;
• a plurality of second lugs defined at spaced intervals on an exterior surface of the steel hub;
• and
• a plurality of second grooves defined in an inner web circumferential surface wherein the plurality of second grooves is complementary to the plurality of the second lugs, and wherein a total quantity of the second grooves is at least equal to a total quantity of the second lugs;
• wherein:
• the gear is to operatively transmit a torque of at least 500 Newton Meters (N·m) for at least 6 million revolutions of the gear;
• an overall mass of the gear is less than two-thirds of an overall mass of a same-sized all steel gear having a solid steel web with a solid steel web thickness at least one-third of a face width of the steel toothed annular flange;
• the web material is a glass fiber reinforced polymer composite;
• the web material includes a plurality of layers of fiberglass reinforcement;
• each layer includes fibers aligned parallel to a layer fiber alignment axis of each layer;
• the layer fiber alignment axis of each layer is skewed with an adjacent layer fiber alignment axis of an adjacent layer;
• the web is bonded to the steel toothed annular flange with a first layer of an adhesive;
• and
• the web is bonded to the steel hub with a second layer of the adhesive;
• a first ratio of a first lug arc length to a first inter-lug space arc length is equal to a first strength ratio of a shear strength of the web material to a shear strength of the steel in the steel toothed annular flange;
• a second ratio of a second lug arc length to a second inter-lug space arc length is equal to a second strength ratio of the shear strength of the web material to a shear strength of the steel in the steel hub;
• the first lug arc length and the first inter-lug space arc length are determined at a first root circle of the plurality of the first lugs;
• the second lug arc length and the second inter-lug space arc length are determined at a second root circle of the plurality of the second lugs;
• the web has a uniform web thickness except where lightening apertures are defined in the web;
• and
• a total quantity of the lightening apertures is thirteen.