204, 206 are coupled, the first and third baffle portions 326, 330 engage form a first baffle and the second and fourth baffle portions 328, 332 engage to form a second baffle, the first and second baffles being disposed within the internal cavity of the housing 202. When the worm gear 208 and the worm wheel 210 are disposed in the housing 202, the first and second baffles are disposed adjacent to a portion of the worm wheel 210. The first and second baffles help direct lubricant up to the gear mesh, as disclosed in further detail herein. In some examples, when the first and second housing portion 204, 206 are coupled, the first and third baffle portions 326, 330 are sealingly engaged or coupled, such that fluid cannot escape between the first and third baffle portions 326, 330. The second and fourth baffle portions 328, 332 are similarly sealingly engaged or coupled. In the illustrated example, the first and second baffles have a curved or arcuate shape. In some examples, the first and second baffles have the same radius of curvature as the worm wheel 210.

In the illustrated example of FIG. 3, the first and housing portions 204, 206 have fluid service holes 334. The fluid service holes 334 enable a person or machine to fill and/or drain fluid/lubricant from the internal cavity of the housing 202. In the examples disclosed herein, the worm gear assembly 200 includes a lubricant to lubricate the gears to reduce friction. The fluid service holes 334 allow for the lubricant to be drained and/or filled easily without the need to disassemble the worm gear assembly 200. In some examples, only one of the housing portions 204, 206 may have a fluid service hole.

FIGS. 4A and 4B are perspective views of opposite sides of the example worm wheel 210 and the second shaft 214. In some examples, the worm wheel 210 and the second shaft 214 are constructed as a single unitary part or component (e.g., a monolithic structure). In other examples, the worm wheel 210 and the second shaft 214 are separate components that are non-rotatably coupled, such as via welding, press fit, or one or more fasteners.

In the illustrated example, the worm wheel 210 has a first side surface 400, a second side surface 402 opposite the first side surface 400, and a peripheral edge 404 between the first and second side surfaces 400, 402. In the illustrated example, the second shaft 214 extends perpendicularly outward from the first and second side surfaces 400, 402.

In the illustrated example, the peripheral edge 404 of the worm wheel 210 has or forms a plurality of teeth 406 (three of which are referenced in each of FIGS. 4A and 4B). Each of the teeth 406 extends between the first and second side surfaces 400, 402. The teeth 406 are shaped and sized to mesh with the worm gear 208. In some examples, the teeth 406 are arranged at a designated lead angle (e.g., an angle between the orientation of the first plurality of teeth 406 of the worm wheel 210 and a plane of rotation). In some examples, the designated lead angle may be between 25°-30°. In other examples, the lead angle can be higher or lower.

As shown in FIG. 4A, the worm wheel 210 has a first plurality of vanes 408 (one of which is referenced in FIG. 4A) on the first side surface 400. In some examples, the first plurality of vanes 408 are formed integrally with the first side surface 400. Each of the vanes 408 extends radially between a center or central region of the first side surface 400 and the peripheral edge 404. The vanes 408 collect lubricant as the worm wheel 210 rotates (e.g., when the actuator 116 drives the worm gear assembly 200), as disclosed in further detail herein. In this example, the vanes 408 are spaced equidistant from each other around the first side surface 400. In the illustrated example, there are twelve (12) vanes 408 on the first side surface 400. In some examples, the first side surface 400 includes one vane 408 for every one of the first plurality of teeth 406 on the peripheral edge 404. In the illustrated example, the vanes 408 are arranged such that the distal ends of the vanes 408 are aligned with the teeth 406 at the intersection of the first side surface 400 and the peripheral edge 404. In other examples, the first side surface 400 can have more or fewer vanes 408 and/or the vanes 408 can be spaced differently. In the illustrated example, each of the vanes 408 has a substantially constant cross-sectional width between the central region and the distal end.

As shown in FIG. 4B, the worm wheel 210 has a second plurality of vanes 410 (one of which is referenced in FIG. 4B). In some examples, the second plurality of vanes 410 are formed integrally with the second side surface 402. Each of the vanes 410 extends radially between a center or central region of the second side surface 402 and the peripheral edge 404. The vanes 410 collect lubricant as the worm wheel 210 rotates (e.g., when the actuator 116 drives the worm gear assembly 200), as disclosed in further detail herein. In this example, the vanes 410 are spaced equidistant from each other around the second side surface 402. In the illustrated example, each of the vanes 408 has a substantially constant cross-sectional width between the central region and the distal end. In the illustrated example, the vanes 410 are arranged such that the distal ends of the vanes 410 are aligned with the teeth 406 at the intersection of the second side surface 402 and the peripheral edge 404. In the illustrated example, there are twelve (12) vanes 410 on the second side surface 402. As such, in some examples, the worm wheel 210 has the same number of vanes 408, 410 on each side as the number of teeth 406. In other examples, the second side surface 402 can have more or fewer vanes 410 and/or the vanes 410 can be spaced differently.

FIG. 5 is a perspective view of the example worm gear 208 and the first shaft 212. In some examples, the worm gear 208 and the first shaft 212 are constructed as a single unitary part or component (e.g., a monolithic structure). In other examples, the worm gear 208 and the first shaft 212 are separate components that are non-rotatably coupled, such as via welding, press fit, or one or more fasteners. In some examples, the first shaft 212 is driven by the actuator 116, which then drives the worm wheel 210 to move the flaps 112, 114 to the desired position.

In the illustrated example, the worm gear 208 includes a screw or spiral tooth 500. In this examples, the spiral tooth 500 makes three turns, and may be considered there separate teeth. In other examples, the worm gear 208 can include more or fewer turns or teeth (e.g., one tooth, two teeth, four teeth, etc.). The spiral tooth 500 of the worm gear 208 of FIG. 5 may be oriented at a corresponding lead angle to that of teeth 406 (FIGS. 4A and 4B) such that when the worm gear 208 is rotated by the actuator 116 rotating the first shaft 212, the teeth 406 of the worm wheel 210 are meshed with the spiral tooth 500 of the worm gear 208 to rotate the worm wheel 210. While the configuration disclosed herein has the actuator 116 driving the worm gear 208, an alternate configuration may be covered herein where the actuator 116 drives the worm wheel 210 to rotate the worm gear 208 to change the position of the flaps 112, 114.

FIG. 6 is a partially assembled view of the worm gear assembly 200 showing the worm gear 208 and the worm wheel 210 inside the first housing portion 204. The first and second baffles (e.g., the first, second, third, and fourth baffle portions 326, 328, 330, 332) partially surround the worm wheel 210 when the worm wheel 210 is inside the housing 202. Additionally, the first shaft 212 extends through the first and second shaft openings (e.g., formed by the first, second, third, and fourth semi-circular grooves 314, 316, 318, 320). In some examples, as disclosed above, the first shaft 212 is operably connected to the actuator 116.

FIG. 7 is a cross-sectional view of the worm gear assembly 200 with the worm gear 208 and the worm wheel 210 inside the housing 202. As illustrated in FIG. 7, the second shaft 214 extends through the third and fourth shaft openings 322, 324. In some examples, as disclosed above, the second shaft 214 is operably connected to the flaps 112, 114 to change the position of the flaps 112, 114.

In the illustrated example, the housing 202 defines an internal cavity 701 (e.g., a chamber). The worm gear 208 and the worm wheel 210 are disposed in the cavity 701 and are meshed together. In the illustrated example, the worm gear 208 is over or above the worm wheel 210 relative to the ground. In some examples, the worm gear assembly 200 is disposed in this orientation when coupled to the aircraft 102 (FIG. 1).

The worm gear assembly 200 can include a lubricant (e.g., oil) to lubricate the gears. As shown in FIG. 7, a lubricant pool 700 is formed along a bottom portion 703 of the internal cavity 701 of the housing 202. The worm wheel 210 is partially disposed in the lubricant pool 700. As disclosed in further detail herein, the worm wheel 210 collects and distributes the lubricant up to the gear mesh between the worm gear 208 and the worm wheel 210. In some examples, the lubricant pool 700 may contain only a small amount of lubricant. For example, the lubricant pool 700 may include 10-20 milliliters (mL) of lubricant (e.g., about 1 tablespoon). In other examples, the lubricant pool 700 may include more or less lubricant to sufficiently lubricate the gear mesh and reduce frictional wearing.

In the illustrated example of FIG. 7, the vanes 408, 410 on the worm wheel 210 are separated or spaced apart from the inner sides of the housing 202. In particular, the vanes 408 on the first side surface 400 of the worm wheel 210 are separated from the first side 300 of the first housing portion 204 by a clearance 702. Similarly, the vanes 410 on the second side surface 402 of the worm wheel are separated from the first side 304 of the second housing portion 206 by the clearance 702. As such, the vanes 408, 410 do not rub or slide against the inner surfaces of the housing 202. The clearance 702 is large enough to prevent rubbing, but small enough to prevent or reduce lubricant from leaking downward between the vanes 408, 410 and the first sides 300, 304 (the inner surfaces) of the housing 202. In some examples, the clearance 702 separating the vanes 408, 410 from the housing 202 is about 0.060 inches (e.g., ±0.005 inches). In other examples, the clearance 702 may be more or less than 0.060 inches. The clearance 702 may be determined by or based on the type of lubricant being used (e.g., the viscosity of the lubricant, amount of lubricant being used, etc.), the application in which the worm gear assembly is being used (e.g., an aircraft, a spacecraft, etc.), the temperature of the intended environment, etc.

FIGS. 8A-8C show an example sequence of movement of the lubricant as the worm wheel 210 rotates. In the example sequence of FIGS. 8A-8C, the worm wheel 210 is rotating in a counterclockwise direction. However, the same performance/functions can be achieved by rotating the worm wheel 210 in a clockwise direction. The example sequence is described in connection with one of the vanes, referenced as the vane 408a. It is understood the example sequence occurs with the other vanes 408, 410.

As shown in FIG. 8A, the worm gear 208 is disposed above or over the worm wheel 210. The worm gear 208 is meshed with the worm wheel 210. The vanes 408 collect and distribute the lubricant up into the mesh of the worm gear 208 and the worm wheel 210. The worm wheel 210 is disposed between first and second baffles 800, 802. The first baffle 800 is formed by the first and third baffle portions 326, 330 (FIG. 3) and the second baffle 802 is formed by the second and fourth baffle portions 328, 332 (FIG. 3).

As shown in FIG. 8A, the first baffle 800 has a bottom edge 804 that is spaced from a bottom 806 of the housing 202. The second baffle 802 similarly has a bottom edge 808 that is spaced from the bottom 806 of the housing 202. This enables lubricant to flow back down from the top of the housing 202 and collect in the lubricant pool 700.

FIG. 8A shows a first stage 810 of the lubricant movement. As illustrated in FIG. 8A, the vane 408a is exiting the lubricant pool 700 and passing the bottom edge 804 of the first baffle 800.

As shown in the callout in FIG. 8A, the vane 408a collects lubricant from the lubricant pool 700 (indicated by arrow 812). In some examples, the vane 408a collects one or more (e.g., a few) drops of lubricant every time the vane 408a moves through the lubricant pool 700. The drops of lubricant stick or adhere to a side 813 of the vane 408a via surface tension.

When the vane 408 rotates past the bottom edge 804 as illustrated in FIG. 8A, the lubricant is subjected to a centrifugal force that forces the lubricant radially outward from the center of the worm wheel 210 (indicated by arrow 814). In particular, the worm gear 208 and the worm wheel 210 may be driven at a relatively high speed. This high speed creates a centrifugal force that forces the lubricant radially outward along the vane 408a. The first baffle 800 provides a barrier to keep the lubricant within a lubricant pocket 816 while the worm wheel 210 rotates to move the lubricant upward. The pocket 816 is formed by the vane 408a, an adjacent vane, and the first baffle 800. When subjected to the centrifugal force, the lubricant bounces off/is stopped by the first baffle 800 and is forced back into the lubricant pocket 816 (indicated by arrow 818). While the intended path for the lubricant is to be forced back into the lubricant pocket 816, some of the lubricant may fall between the vane 408a and the first baffle 800.

FIG. 8B shows a second stage 820 of the lubricant movement. As illustrated in FIG. 8B, the worm wheel 210 is in rotation after collecting the lubricant from the first stage 810. The first baffle 800 maintains the barrier to keep the lubricant subjected to the centrifugal force (arrow 814) within the lubricant pocket 816 by forcing the lubricant back into the lubricant pocket 816 (arrow 818).

FIG. 8C shows a third stage 822 of the lubricant movement. As illustrated in FIG. 8C, the first baffle 800 has a top edge 824 that is spaced from the top of the housing 202 and the worm gear 208. Similarly, the second baffle has a top edge 826 that is spaced from the top of the housing 202 and the worm gear 208. The top edges 824, 826 being separated from the top of the housing 202 allow lubricant to escape the lubricant pocket 816. In some examples, once the worm wheel 210 rotates to a position where the vane 408a is no longer surrounded by the first baffle 800 (e.g., the vane 408a has rotated past the top edge 824), the centrifugal force causes the lubricant to break away from the vane 408a (indicated by arrow 828). The lubricant is flung or sprayed into the mesh between the worm gear 208 and the worm wheel 210. Therefore, the vane 408a moves lubricant from the bottom 806 of the housing 202 to the worm gear 208 to lubricate an interface between the worm gear 208 and the worm wheel 210.

In some examples, when the worm wheel 210 has one vane 408 for every one of the first plurality of teeth 406 (on the first side surface 400 and/or the second side surface 402 of FIG. 4), the worm wheel 210 is constantly collecting lubricant as the worm wheel 210 rotates. This allows the worm gear assembly 200 to constantly maintain a lubricated state while the worm gear assembly 200 is in operation.

FIG. 9 illustrates an example return path for the lubricant during operation of the worm gear assembly 200. In some examples, not all the lubricant from the lubricant pocket 816 is meshed with the teeth 406, 500 (FIG. 4 and FIG. 5). As indicated by arrow 900, some of the lubricant is flung from the lubricant pocket 816, over the top edge 824 of the first baffle 800 and flows down the opposite side of the first baffle 800 (e.g., opposite of the worm wheel 210) and is collected back into the lubricant pool 700. Some of the lubricant is moved along the gear mesh to the left side of the housing 202. As indicated by arrow 902, some of the lubricant is sprayed outward, over the top edge 826 of the second baffle 802. As indicated by arrow 904, the lubricant flows down the outside side of the second baffle 802 (e.g., opposite of the worm wheel 210) and is collected back into the lubricant pool 700. Allowing lubricant to collect back into the lubricant pool 700 keeps the teeth 406, 500 lubricated while not requiring all of the lubricant from the lubricant pocket 816 to be forced into the meshing of the teeth 406, 500. Additionally, returning unused lubricant back to the lubricant pool 700 allows future rotations of the worm wheel 210 to collect a sufficient amount of lubricant to continue to lubricate the worm gear assembly 200.

FIG. 10 is an enlarged view of the vane 408a of the worm wheel 210 along the first baffle 800. The other vanes 408, 410 are the same as the vane 408a. As such, any of the example aspects disclosed in connection with the vane 408a can likewise apply to the other vanes 408, 410. As shown in FIG. 10, the vane 408a has a distal end or tip 1002 at or near the peripheral edge 404 (FIG. 4) of the worm wheel 210. The tip 1002 is separated or spaced from the first baffle 800 by a clearance 1000. As such, the vane 408a does not engage or rub on the first baffle 800. The vane 408 may be similarly spaced from the second baffle 802 (FIGS. 8A-8C). The clearance 1000 is large enough to prevent rubbing, but small enough to prevent or reduce droplets of lubricant from leaking downward between the tip 1002 and the first baffle 800. In some examples, the clearance 1000 is about 0.030 inches (e.g., ±0.005 inches). In other examples, the clearance 1000 may be greater than or less than 0.030 inches. In some examples, the clearance 1000 may be determined by or based on the type of lubricant (e.g., based on the viscosity of the lubricant). For example, higher viscosity lubricants may allow for a larger clearance 1000 because the lubricant may form larger droplets. In other examples, the clearance 1000 may be smaller where the lubricant is less viscous.

In some examples, the tip 1002 of the vane 408a is shaped so as to break a surface tension of the lubricant droplets to enable the lubricant to be flung off of the vane 408a and thereby dispense the lubricant into the interface between the worm gear 208 and the worm wheel 210. For example, as shown in FIG. 10, the tip 1002 is square-shaped, which includes a sharp (e.g., 90°) corner or edge. Alternatively, any other shape may be interchangeably used herein to break the surface tension of the lubricant to allow the lubricant to be flung onto the gear mesh.

FIG. 11 shows an example rig 1100 for supporting the worm gear assembly 200. The rig 1100 may be used to couple the worm gear assembly 200 to another structure, such as to a wing of an aircraft. In some examples, the rig 1100 includes an opening for each of the shafts 212, 214 (e.g., the first shaft