Gear pair lubrication device

Abstract

To provide a gear pair lubrication device capable of improving lubrication of a tooth surface.SOLUTION: A lubrication device comprises a supply unit that supplies lubricant to the end of meshing of a gear pair. The lubrication device preferably comprises a wall that faces a portion other than curved surfaces in a portion at the end of meshing formed by making a curved surface connecting the tips of teeth of a drive gear and a curved surface connecting the tips of teeth of a driven gear intersect with each other. The supply unit preferably supplies lubricant to the portion other than the curved surfaces in the portion at the end of meshing formed by making the curved surface connecting the tips of the teeth of the drive gear and the curved surface connecting the tips of the teeth of the driven gear intersect with each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gear pair lubrication system. [Background technology]

[0002] Patent Document 1 discloses a prior art gear lubrication device that supplies lubricating oil (hereinafter referred to as "oil") to the portion where a pair of gears begins to mesh. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-158116 Summary of the Invention [Problem to be solved by the invention]

[0004] In the prior art, the oil is sometimes repelled by the tips of the rotating gear teeth, or is splashed by the air currents generated by the rotation of the gears, resulting in insufficient lubrication of the tooth surfaces.

[0005] The present invention has been made to solve this problem, and has as its object to provide a gear pair lubricating device that can provide good lubrication of the tooth surfaces. [Means for solving the problem]

[0006] A first aspect for achieving this object is a lubrication device for a gear pair in which a drive gear and a driven gear mesh together, which includes a supply unit that supplies lubricating oil to the end of meshing of the gear pair.

[0007] The second embodiment is the first embodiment, in which a wall is provided that faces the part other than the curved surface formed by the intersection of the curved surface connecting the tips of the teeth of the drive gear and the curved surface connecting the tips of the teeth of the driven gear at the end of meshing.

[0008] In a third aspect, in the second aspect, the gear pair includes helical gears, and the wall is disposed at least on the side where the teeth at the end of meshing separate first.

[0009] In a fourth aspect, in any of the first to third aspects, the supply unit supplies lubricating oil to the area other than the curved surface formed by the intersection of the curved surface connecting the tips of the teeth of the drive gear and the curved surface connecting the tips of the teeth of the driven gear at the end of meshing.

[0010] In a fifth aspect, in any of the first to fourth aspects, a cover is provided that faces the curved surface connecting the tips of the teeth of the drive gear and the curved surface connecting the tips of the teeth of the driven gear at the end of meshing.

[0011] In a sixth embodiment, the fifth embodiment further includes a container for storing lubricating oil, the meshing end of the gear pair being positioned vertically above the meshing start of the gear pair, and the bottom of the container also serves as a cover.

[0012] A seventh aspect is any of the first to sixth aspects, further comprising a container for storing lubricating oil and a pipe connected to the container through which the lubricating oil stored in the container flows, the supply unit being provided in the pipe and being positioned vertically below the container. [Effects of the Invention]

[0013] According to the present invention, oil is supplied to the end of meshing of the gear pair where negative pressure is generated, thereby ensuring good lubrication of the tooth surfaces. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view of a lubricating device according to a first embodiment. [Figure 2] FIG. 2 is a side view of a gear pair with an enlarged meshing portion. [Figure 3] FIG. [Figure 4] FIG. 10 is a side view of a lubricating device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a lubrication device 10 according to a first embodiment. The lubrication device 10 is disposed on a gear pair 20. There is no limitation on the use of the gear pair 20, but an example is one in which it is mounted on a vehicle (not shown).

[0016] The gear pair 20 includes a drive gear 21 and a driven gear 23 that meshes with the drive gear 21. The drive gear 21 is disposed on a gear shaft 22, and the driven gear 23 is disposed on a gear shaft 24. A gear 25 that meshes with another gear (not shown) is disposed on the gear shaft 24.

[0017] In this embodiment, the gear shafts 22 and 24 are parallel shafts, and the drive gear 21, driven gear 23, and gear 25 are helical gears. In Fig. 1, the drive gear 21 rotates clockwise, and the driven gear 23 rotates counterclockwise. The lubrication device 10 includes a supply unit 11 that supplies oil to the end of meshing of the gear pair 20.

[0018] Figure 2 is a side view of gear pair 20 with an enlarged meshing portion. The two arrows in Figure 2 indicate the rotational directions of drive gear 21 and driven gear 23, respectively. Drive gear 21 forms a curved surface 29 (cylindrical surface) including an addendum circle connecting tips 27 of teeth 26 of drive gear 21, and a curved surface 30 including a root circle connecting bottoms 28 of teeth 26. Driven gear 23 forms a curved surface 34 (cylindrical surface) including an addendum circle connecting tips 32 of teeth 31 of driven gear 23, and a curved surface 35 including a root circle connecting bottoms 33 of teeth 31.

[0019] The meshing of the drive gear 21 and driven gear 23 creates an area 36 (filled in with diagonal lines) where the curved surface 29 and the curved surface 34 intersect. The pitch point 37 is the point where the drive gear 21 and the driven gear 23 come into contact. In Figure 2, the area below the pitch point 37 is the start of meshing of the gear pair 20 (the approaching side), and the area above the pitch point 37 is the end of meshing of the gear pair 20 (the receding side).

[0020] The supply unit 11 (see Figure 1) supplies oil to the end of meshing of the gear pair 20, above the pitch point 37. When the gear pair 20 rotates, an air flow is generated on the sides and tips 27, 32 of the teeth 26, 31, moving at a speed similar to the rotational speed of the gear pair 20. Oil is carried by this flow and supplied to the meshing portion of the gear pair 20. The space created by the meshing of the drive gear 21 and driven gear 23 gradually becomes smaller on the approaching side of the pitch point 37 and gradually becomes larger on the receding side. Because the space between the drive gear 21 and driven gear 23 on the receding side becomes negative pressure, the supplied oil is sucked into this space. The oil sucked into the space moves toward the tips 27, 32 of the teeth 26, 31 as the gear pair 20 rotates, forming an oil film at the pitch point 37. This ensures good lubrication of the tooth surfaces.

[0021] Returning to Figure 1, the lubrication device 10 includes a container 12 that stores oil. The container 12 is disposed vertically above the gear pair 20. A part of a case (not shown) that houses the gear pair 20 can also serve as a lid for the container 12.

[0022] There is no limitation on the means for storing oil in the container 12, but examples include a pump that draws up oil collected at the bottom of a case that houses the gear pair 20 into the container 12, a pump that uses oil to cool a motor (not shown) mounted on a vehicle and supplies oil to the container 12, and a pump that uses the rotation of a gear (not limited to the gear pair 20) or a rotating object to scoop up the oil and supply it to the container 12. The drive source for the pump is exemplified by an engine or a motor.

[0023] The lubrication device 10 includes a pipe 13 that guides oil stored in a container 12 to the end of meshing of the gear pair 20. In this embodiment, the opening at the tip of the pipe 13 is the supply unit 11. Because the supply unit 11 is located vertically below the container 12, even if there is no power to supply oil to the gear pair 20, the oil stored in the container 12 can be supplied from the pipe 13 to the tooth surfaces by the suction force at the end of meshing of the gear pair 20 and gravity.

[0024] 3 is a side view of the lubricating device 10. The lubricating device 10 includes a wall 14 that faces a portion of the portion 36 other than the curved surfaces 29 and 34 (the side surfaces of the teeth 26 and 31 (see FIG. 2)). A gap is provided between the wall 14 and the teeth 26 and 31 so that the wall 14 does not come into contact with the rotating gear pair 20. The wall 14 faces a distal portion of the portion 36 (the portion above the pitch point 37 (see FIG. 2)).

[0025] In this embodiment, wall 14 is connected to the wall of container 12. Wall 14 not only faces the parts of portion 36 other than curved surfaces 29 and 34, but also extends inside curved surface 30, faces half the circumference of tooth 26, and extends inside curved surface 35, faces one-quarter the circumference of tooth 31. By using container 12 to fix wall 14, it is possible to eliminate the need to provide a separate member for fixing wall 14.

[0026] Because walls 14 are provided on the sides of the teeth 26, 31 (see Figure 2), airflow occurs between the rotating gear pair 20 and walls 14, reducing the amount of oil that leaks out from the sides of the teeth 26, 31 when supplied to the end of meshing of the gear pair 20. This increases the amount of oil that reaches the tooth surfaces.

[0027] Wall 14 is disposed at least on the side of gear pair 20, which is made up of helical gears, where teeth 26, 31 (see FIG. 2) at the end of meshing separate first (the front side of the paper in FIG. 1). Oil accumulated between wall 14 and teeth 26, 31 moves axially along the tooth trace as gear pair 20 rotates, lubricating the tooth surfaces of gear pair 20 across the entire tooth width.

[0028] In this embodiment, the wall 14 is disposed only on the side of the gear pair 20 where the meshing end teeth 26, 31 (see FIG. 2) separate first (the front side of the paper in FIG. 1). This makes it easier to arrange the wall 14 on the gear pair 20 compared to when the wall 14 is disposed on both sides of the gear pair 20.

[0029] A hole 15 (see FIG. 1) through which pipe 13 passes is provided in wall 14. Hole 15 faces a portion of portion 36 (see FIG. 2) other than curved surfaces 29, 34. An opening (supply portion 11) at the tip of pipe 13 passing through hole 15 faces a portion of portion 36 other than curved surfaces 29, 34 and above pitch point 37 (the side surfaces of teeth 26, 31).

[0030] When the gear pair 20 is not rotating, most of the oil supplied from the supply unit 11 to the side surfaces of the teeth 26, 31 hits the side surfaces of the teeth 26, 31 and falls. However, when the gear pair 20 rotates, the air flow generated on the side surfaces of the teeth 26, 31 closes the gap between the teeth 26, 31 and the wall 14, and the space between the driving gear 21 and the driven gear 23 on the far side becomes negative pressure, so that the oil is sucked into the meshing parts of the gear pair 20. Because the oil is supplied to the tooth surfaces from the side surfaces of the teeth 26, 31, the amount of oil that is repelled by the tips 27, 32 of the rotating teeth 26, 31 and does not reach the tooth surfaces can be reduced compared to when oil is supplied from a position facing the curved surfaces 29, 34.

[0031] As the rotation speed of the gear pair 20 increases, the negative pressure in the space between the driving gear 21 and the driven gear 23 on the far side increases, and the suction force increases, so the flow rate of oil supplied from the container 12 to the meshing parts of the gear pair 20 increases. This ensures sufficient lubrication even when the rotation speed of the gear pair 20 increases.

[0032] The lubricating device 10 includes a cover 16 that faces the curved surfaces 29, 34 at the end of meshing of the gear pair 20. A gap is provided between the cover 16 and the curved surfaces 29, 34 so that the cover 16 does not come into contact with the rotating gear pair 20. In this embodiment, the cover 16 is connected to the wall 14, and the cover 16 also serves as the bottom of the container 12. The cover 16 faces approximately half the circumference of the curved surface 29 and approximately one-quarter of the circumference of the curved surface 34.

[0033] The oil supplied at the end of meshing of gear pair 20 is expected to flow between cover 16 and curved surface 29 and between drive gear 21 and wall 14 as gear pair 20 rotates, thereby cooling drive gear 21. The oil is also expected to flow between cover 16 and curved surface 34 and between driven gear 23 and wall 14, thereby cooling driven gear 23. Furthermore, because the area of ​​gear pair 20 covered by wall 14 and cover 16 is only part of the area of ​​gear pair 20, the stirring resistance of the gears can be reduced and the vicinity of the source of heat generated by the gears driving can be effectively cooled.

[0034] Since the cover 16 is connected to the wall 14, fixing the cover 16 to the wall 14 eliminates the need to provide a separate member for fixing the cover 16. Furthermore, since the cover 16 also serves as the bottom of the container 12, the volume of the container 12 can be secured when the container 12 is placed vertically above the cover 16 in a case (not shown) for the gear pair 20.

[0035] A second embodiment will be described with reference to Figure 4. In the first embodiment, the case where the meshing end of the gear pair 20 is located vertically above the meshing start point has been described. In contrast, in the second embodiment, the case where the meshing end of the gear pair 20 is located vertically below the meshing start point will be described. In the second embodiment, the same parts as those described in the first embodiment are designated by the same reference numerals, and the following description will be omitted.

[0036] Fig. 4 is a side view of a lubrication device 40 according to a second embodiment. In Fig. 4, the rotation direction of the drive gear 21 of the gear pair 20 is counterclockwise, and the rotation direction of the driven gear 23 is clockwise. The lubrication device 40 includes a container 42 for storing oil and a pipe 43 connected to the container 42. The container 42 is disposed vertically above the gear pair 20, and an opening (supply portion 41) at the tip of the pipe 43 supplies the oil in the container 42 to the gear pair 20 at the end of meshing by utilizing gravity.

[0037] The lubricating device 40 includes a wall 44 that faces a portion of the portion 36 other than the curved surfaces 29, 34 (the side surfaces of the teeth 26, 31 (see FIG. 2)). The wall 44 faces a portion of the portion 36 on the far side (the portion below the pitch point 37 (see FIG. 2)). A hole (not shown) through which a pipe 43 passes is provided in the wall 44, and the pipe 43 passes through the wall 44. When the gear pair 20 is not rotating, most of the oil supplied from the supply unit 41 to the side surfaces of the teeth 26, 31 (see FIG. 2) hits the side surfaces of the teeth 26, 31 and falls. However, when the gear pair 20 rotates, the space between the driving gear 21 and the driven gear 23 on the far side becomes negative pressure, and the oil is sucked into the meshing portions of the gear pair 20 to lubricate the tooth surfaces, as in the first embodiment.

[0038] Lubrication device 40 includes a cover 45 that faces curved surfaces 29, 34 at the end of meshing of gear pair 20. Oil supplied to the end of meshing of gear pair 20 is expected to flow between cover 45 and curved surface 29 as gear pair 20 rotates, thereby cooling drive gear 21, and to flow between cover 45 and curved surface 34, thereby cooling driven gear 23.

[0039] The present invention has been described above based on an embodiment, but the present invention is not limited to this embodiment in any way, and it can be easily inferred that various improvements and modifications are possible within the scope of the present invention without departing from the spirit of the present invention.

[0040] In the embodiment, the gear pair 20 has been described using helical gears with parallel axes as an example, but this is not necessarily limited to this. The lubrication device can also lubricate other gear pairs. Examples of other gear pairs include: (1) gear pairs with parallel axes such as a spur gear and a spur gear, a spur gear and a rack, an internal gear (spur gear) and an external gear, a helical internal gear and a helical external gear, and a helical gear and a helical rack; (2) gear pairs with intersecting axes such as straight bevel gears, spiral bevel gears, and zerol bevel gears; and (3) gear pairs with non-intersecting axes such as cylindrical worm gears and crossed screw gears.

[0041] In the embodiment, when oil is supplied to a portion other than the curved surfaces 29, 34 of the meshing end portion 36 of the gear pair 20, the openings of the pipes 13, 43 are directed toward a portion of the portion 36 on the far side of the pitch point 37. However, this is not necessarily limited to this. If oil is supplied to the meshing end portion of the gear pair 20, it is of course possible to supply oil by directing the openings of the pipes 13, 43 toward a portion of the side surface of the drive gear 21 or the driven gear 23 other than the portion 36. This is because, when at least a portion of the oil supplied to the side surface of the drive gear 21 or the driven gear 23 other than the portion 36 is carried by the rotation of the gear pair 20 to the portion of the portion 36 on the far side of the pitch point 37, the same operational effect as that of the lubrication devices 10, 40 in the embodiment can be obtained. Therefore, in this case as well, the openings (supply portions) of the pipes 13, 43 supply oil to a portion other than the curved surfaces 29, 34 of the portion 36.

[0042] In the embodiment, the oil stored in the containers 12, 42 is supplied to the gear pair 20 from the pipes 13, 43 by gravity, but this is not necessarily limited to this. It is of course possible to omit the containers 12, 42 and the pipes 13, 43 and instead use a pump to spray oil from a nozzle toward the meshing end of the gear pair 20, or to scoop up oil accumulated at the bottom of the case that houses the gear pair 20 and spray it onto the meshing end of the gear pair 20. In this case, the nozzle or the means for scooping up the oil (such as an impeller) is the supply unit. If the walls 14, 44 or the covers 16, 45 interfere with the supply of oil to the meshing end, it is of course possible to omit the walls 14, 44 or the covers 16, 45.

[0043] In the first embodiment, the oil stored in the container 12 is supplied to the gear pair 20 using the pipe 13, but this is not necessarily limited to this. It is of course possible to omit the pipe 13 and instead drill a hole in the cover 16, which also serves as the bottom of the container 12, near the end of meshing of the gear pair 20, allowing the oil to drop through the hole and supplying the oil to the end of meshing of the gear pair 20. In this case, the hole in the cover 16 is the supply part.

[0044] Although not described in the embodiment, it is of course possible to provide a sensor that detects the rotation speed of the gear pair 20 and adjust the amount of oil supplied to the end of meshing of the gear pair 20 according to the rotation speed of the gear pair 20. This allows the gear pair 20 to be lubricated without being supplied with excessive oil. [Explanation of symbols]

[0045] 10,40 Lubricating device 11,41 Supply section 12,42 container 13,43 tube 14,44 Wall 16,45 Cover 20 gear pairs 21 Drive gear 23 Driven gear 26,31 teeth 27,32 Tip 29,34 curved surface 36 parts

Claims

1. A lubrication device for a gear pair in which a drive gear and a driven gear mesh together, comprising: a lubrication device including a supply section for supplying lubricating oil to the meshing end of the gear pair;

2. 2. The lubrication device according to claim 1, further comprising a wall facing a portion of the end of meshing formed by the intersection of a curved surface connecting the tips of the teeth of the drive gear and a curved surface connecting the tips of the teeth of the driven gear, the portion being other than the curved surface.

3. the gear pair includes a helical gear, 3. The lubricating device according to claim 2, wherein the wall is disposed at least on the side of the gear pair from which the teeth at the end of meshing separate first.

4. 4. A lubrication device according to claim 1, wherein the supply unit supplies lubricating oil to a portion of the intersecting curved surface connecting the tips of the teeth of the drive gear and the curved surface connecting the tips of the teeth of the driven gear at the end of meshing, other than the curved surface.

5. 4. The lubrication device according to claim 1, further comprising a cover that faces a curved surface connecting the tips of the teeth of the drive gear and a curved surface connecting the tips of the teeth of the driven gear at the end of meshing.

6. Equipped with a container for storing lubricating oil, the meshing end is located vertically above the meshing start of the gear pair, 6. The lubricating device according to claim 5, wherein the bottom of said container also serves as said cover.

7. A container for storing lubricating oil; a pipe connected to the container through which the lubricating oil stored in the container flows; 4. The lubricating device according to claim 1, wherein the supply portion is provided in the pipe and is positioned vertically below the container.

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