Gearbox and Self-Renewing Air Filter

An apparatus for renewing a sheet-type filtering material in a flowing fluid inside a conduit, said flow applying a force to a force transferring device to ultimately cause movement of the sheet-type filtering material, the apparatus comprising:

• (a) a gathering roll to which one end of the sheet-type filtering material is attached;
• (b) a frame for stretching the sheet-type filtering material across the conduit;
• and
• (c) a force gathering device;
• (c) a gearbox operatively attached at one end to the force gathering device and being operatively attached at the other end to the gathering roll to advance the sheet-type filtering material across the conduit such that clean filtering material is exposed to the fluid flow.

A gearbox comprising:

• an input end operatively attached to an input and an output operatively attached to something desired to be powered by the input;
• a first set of intermeshing gears in operatively attached to the input and a second set of intermeshing gears operatively attached to the first set of intermeshing gears to transfer rotational power to the second set of intermeshing gears, the first and second set of intermeshing gears being of a configuration and size to thereby both reduce a rotational input speed to a much slower speed of rotation at the second set of intermeshing gears, while at the same time increasing the torque of rotation at the second set of intermeshing gears as compared to the torque of rotation of the input;
• (a) a first worm (1w) gear rigidly operatively attached to the input (2p) for rotation about a second axis (2a) of rotation;
• (b) a second worm gear (2w) operatively rotatably attached to the gearbox about a third rotational axis (3a), the second worm gear (2w) being operatively meshing with the first worm gear (1w) whereby rotation of the first worm gear (1w) causes the second worm gear (2w) to rotate;
• (c) a first spur gear (1s) rigidly operatively rigidly attached to the second worm (2w) gear for rotation with the second worm gear (2w) about the third axis of rotation (3a);
• (d) a second spur gear (2s) operatively rotatably attached to the gearbox about a fourth rotational axis (4a), the second spur gear (2s) being operatively meshing with the first spur gear (1s) whereby rotation of the first spur gear (1s) causes the second spur gear (2s) to rotate about the fourth rotational axis (4a);
• and
• (e) wherein the output is operatively attached to the second spur gear (2s) via other gears to cause the output to rotate in response to rotation of the input.