Axle device

Abstract

To provide an axle device capable of securing lubricity by suppressing an increase in agitation resistance.SOLUTION: An axle device 1 includes axle shafts 14, 15, a differential 11, a differential body 21, a temporary storage tank 19, and a shroud 18. The differential 11 transfers rotation of a drive shaft 2 driven by an engine to the axle shafts 14, 15. The differential body 21 stores the differential 11. The temporary storage tank 19 is arranged in the differential body 21, and temporarily accumulates lubrication oil scraped up by a bevel gear 32 of the differential 11. The shroud 18 is arranged in the differential body 21 to cover a lower part of the bevel gear 32. The capacity of the lubrication oil of the temporary storage tank 19 is equal to or less than the height of the lubrication oil and 70% or more and 130% or less of the capacity of the lubrication oil in the shroud 18 when the engine stops.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an axle assembly. [Background technology]

[0002] In a work vehicle, a drive shaft driven by an engine via a transmission is connected to an axle device such as a front axle and a rear axle. A differential is provided on the axle device, and rotation of the drive shaft is transmitted to the axle shaft by the differential. The differential is housed in a differential body, and lubricating oil for lubricating and cooling the differential is stored in the differential body (see, for example, Patent Document 1).

[0003] In the axle device shown in Patent Document 1, a gear cover is provided to cover the lower part of the ring gear of the differential. The rotation of the ring gear scrapes out the lubricating oil inside the gear cover, reducing the amount of lubricating oil around the ring gear and reducing the stirring resistance during high-speed driving.

[0004] However, in areas other than the gear cover, the level of the lubricating oil increases, which increases the stirring resistance of the planetary reducer, for example.

[0005] For this reason, it has been proposed to provide a temporary holding tank to temporarily store the lubricating oil scooped up by the ring gear, thereby preventing an increase in stirring resistance in parts other than the gear cover. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4936947 specification Summary of the Invention [Problem to be solved by the invention]

[0007] However, if the capacity of the temporary holding tank is too small, it is not very effective in preventing an increase in stirring resistance, and if it is too large, there is a risk that the lubrication of the bearings will decrease.

[0008] The present disclosure aims to provide an axle device that can suppress an increase in stirring resistance and ensure lubrication. [Means for solving the problem]

[0009] An axle device according to a first aspect of the present disclosure includes an axle shaft, a differential, a differential body, a temporary holding tank, and a shroud. The differential transmits rotation of a drive shaft driven by an engine to the axle shaft. The differential body houses the differential. The temporary holding tank is disposed in the differential body and temporarily stores lubricating oil scooped up by the differential gears. The shroud is disposed in the differential body and covers the lower part of the gears. The capacity of the lubricating oil in the temporary holding tank is 70% or more and 130% or less of the capacity of the lubricating oil in the shroud below the height of the lubricating oil when the engine is stopped. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide an axle device capable of suppressing an increase in stirring resistance and ensuring lubrication. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional plan view showing an axle assembly according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a longitudinal cross-sectional view showing an axle assembly according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a perspective view showing the configuration of a portion of the axle device according to the present disclosure, the portion extending from the shroud to the right side. [Figure 4] FIG. 2 is a perspective view showing a shroud of the axle assembly of the present disclosure. [Diagram 5] 2 is a cross-sectional view taken along line AA' in FIG. 1. [Figure 6]FIG. 2 is an enlarged view of part B in FIG. [Figure 7] FIG. 2A is a right side view of the shroud, and FIG. [Figure 8] FIG. 1 is a graph showing the change in horsepower loss when the capacity of the temporary holding tank is changed relative to the capacity of the lubricating oil in the shroud. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an axle device according to an embodiment will be described with reference to the drawings.

[0013] (Overall configuration of the axle device) Figure 1 is a plan sectional view of the axle device 1. Figure 2 is a vertical sectional view of the axle device 1. In Figures 1 and 2, the left side of the vehicle when the axle device 1 is mounted on a work vehicle is shown in the left direction L, and the right side is shown in the right direction R.

[0014] The axle device 1 is used in a work vehicle such as a motor grader. The axle device 1 transmits rotation of a drive shaft 2 (FIG. 1) driven by an engine to axle shafts 14, 15. The rotation of the axle shafts 14, 15 rotates the wheels, causing the work vehicle to travel.

[0015] The axle device 1 includes an axle housing 10, a differential 11, transmission shafts 12 and 13, axle shafts 14 and 15, planetary reducers 16 and 17, a shroud 18, and a temporary holding tank 19. The shroud 18 in this specification corresponds to the gear cover of Patent Document 1.

[0016] The axle housing 10 houses a differential 11, transmission shafts 12, 13, axle shafts 14, 15, planetary reduction gears 16, 17, and a shroud 18.

[0017] The differential 11 transmits rotation of a drive shaft 2, which is driven by driving force from an engine (not shown), to each of the transmission shafts 12 and 13. The transmission shafts 12 and 13 are arranged symmetrically in the left-right direction with the drive shaft 2 in between. The transmission shaft 12 is arranged on the left side of the transmission shaft 13 in Fig. 1. The rightward direction in Fig. 1 is indicated by an arrow R, and the leftward direction is indicated by an arrow L.

[0018] The rotation of the transmission shaft 12 is reduced by the planetary reduction gear 16 and transmitted to the axle shaft 14. The rotation of the transmission shaft 13 is reduced by the planetary reduction gear 17 and transmitted to the axle shaft 15. As shown in FIG. 2, the shroud 18 covers the lower part of the bevel gear 32 (one example of a gear of a differential) of the differential 11. The bevel gear 32 in this specification corresponds to the ring gear of Patent Document 1. As shown in FIG. 1, the temporary holding tank 19 is disposed in the differential body 21 of the axle housing 10. The temporary holding tank 19 temporarily stores the lubricating oil scooped up by the bevel gear 32. The lubricating oil is stored in the axle housing 10. The lubricating oil lubricates or cools the differential 11, the planetary reduction gears 16, 17, etc. An oil level H is shown in FIG. 2. The oil level H indicates the height of the lubricating oil when the engine is stopped and no lubricating oil is stored in the temporary storage tank 19. In this state, the space below the oil level H in the axle housing 10 is filled with lubricating oil.

[0019] (Axle housing 10) 1, the axle housing 10 has a differential body 21, a left axle housing 22, and a right axle housing 23. The differential body 21 houses the differential 11. The left axle housing 22 houses the axle shaft 14 and the planetary reduction gear 16. The right axle housing 23 houses the axle shaft 15 and the planetary reduction gear 17.

[0020] The differential body 21 has a drive shaft opening 21a, a left axle opening 21b, and a right axle opening 21c. The drive shaft opening 21a is closed by a pinion cage 3 that is detachably connected to the differential body 21. A drive shaft 2 is rotatably supported by the pinion cage 3. The drive shaft 2 has, at one end, a drive pinion gear 201 (an example of a drive shaft gear) that is constantly meshed with a bevel gear 32 of the differential 11. A coupling 202 is fixed to the other end of the drive shaft 2. The drive shaft 2 can be connected to a propeller shaft that transmits the rotation of the engine via a transmission or the like, using the coupling 202.

[0021] A left axle housing 22 is fixed to the left axle opening 21b so as to close the opening. The internal space of the differential body 21 and the internal space of the left axle housing 22 are connected via the left axle opening 21b, allowing the movement of lubricating oil. A right axle housing 23 is fixed to the right axle opening 21c so as to close the opening. The internal space of the differential body 21 and the internal space of the right axle housing 23 are connected via the right axle opening 21c, allowing the movement of lubricating oil.

[0022] (Differential 11, transmission shafts 12, 13) As shown in FIG. 2, the differential 11 includes a differential case 31, a bevel gear 32, a spider 33, a pinion gear 34, side gears 35 and 36, and a clutch device 37.

[0023] The bevel gear 32 rotates about an axis in the left-right direction. The rotation axis of the bevel gear 32 is indicated as O. The bevel gear 32 is connected to a differential case 31. When the bevel gear 32 rotates by the drive shaft 2, the differential case 31 rotates coaxially with the bevel gear 32. In this specification, the radial direction refers to a direction perpendicular to the axis O and moving toward or away from the axis O. In this specification, vertical, horizontal, or parallel does not have a strict meaning and may include an error, and includes a degree that can be recognized as vertical, horizontal, or parallel in terms of social convention.

[0024] The spider 33 is disposed facing the inside of the differential case 31. The pinion gear 34 is supported by the differential case 31 via the spider 33 so as to be able to rotate freely. Four pinion gears 34 are disposed at 90 degree intervals. The side gears 35, 36 are constantly meshed with the four pinion gears 34. The side gear 35 is disposed on the left side of the side gear 36. The side gear 35 is spline-coupled to the left transmission shaft 12 so as to be coaxial with the side gear 36. The side gear 36 is spline-coupled to the right transmission shaft 13 so as to be coaxial with the side gear 36.

[0025] The clutch device 37 is disposed inside the differential case 31, between the side gear 35 and the differential case 31. The clutch device 37 is, for example, a wet multi-plate clutch. The clutch device 37 locks the differential mechanism.

[0026] 2, the clutch device 37 has clutch plates 371, friction plates 372, and a piston 373. A plurality of clutch plates 371 and friction plates 372 are arranged along the transmission shaft 12. The clutch plates 371 rotate together with the differential case 31. The friction plates 372 are arranged between the clutch plates 371.

[0027] The piston 373 is disposed movably along the transmission shaft 12, and when it moves to the left, the clutch plate 371 is pressed and clamped by the friction plate 372. This brings the clutch device 37 into an ON state, and the transmission shaft 12 and the transmission shaft 13 rotate only at the same rotation speed. On the other hand, when the piston 373 moves to the right, the clamping of the clutch plate 371 by the friction plate 372 is released. This brings the clutch device 37 into an OFF state, and when a rotation difference occurs between the left and right wheels when the vehicle is turning, etc., the transmission shaft 12 and the transmission shaft 13 can rotate at different rotation speeds.

[0028] 1, the drive pinion gear 201 rotates, which in turn rotates the bevel gear 32. The rotation of the bevel gear 32 rotates the differential case 31, which in turn rotates the spider 33. The rotation of the spider 33 rotates the side gears 35, 36 via the pinion gear 34, which in turn rotates the transmission shafts 12, 13.

[0029] (Axle shafts 14 and 15) The axle shaft 14 is disposed on the left side of the transmission shaft 12. The axle shaft 14 is disposed coaxially with the transmission shaft 12. The axle shaft 14 is rotatably supported by the left axle housing 22 via a bearing 41. The rotation of the axle shaft 14 causes the wheels connected to the axle shaft 14 to rotate.

[0030] The axle shaft 15 is disposed on the right side of the transmission shaft 13. The axle shaft 15 is disposed coaxially with the transmission shaft 13. The axle shaft 15 is rotatably supported by the right axle housing 23 via a bearing 42. The rotation of the axle shaft 15 causes the wheels connected to the axle shaft 15 to rotate.

[0031] (Planetary reducer 16, 17) The planetary reduction gear 16 is disposed between the transmission shaft 12 and the axle shaft 14. The planetary reduction gear 16 is housed in the left axle housing 22. The planetary reduction gear 16 reduces the rotation of the transmission shaft 12 and transmits it to the axle shaft 14. The planetary reduction gear 16 has a sun gear 51, a ring gear 52, a plurality of planet gears 53, and a planet carrier 54.

[0032] The sun gear 51 is fixed to an end of the transmission shaft 12. The ring gear 52 is formed on the inner circumferential surface of the left axle housing 22, radially outward of the sun gear 51. A plurality of planetary gears 53 are disposed between the sun gear 51 and the ring gear 52. Each of the planetary gears 53 meshes with the ring gear 52 and the sun gear 51. The planetary carrier 54 rotatably supports the plurality of planetary gears 53. The planetary carrier 54 is splined to the end of the axle shaft 14.

[0033] The rotation of the sun gear 51 causes the planetary gears 53 to rotate on their own axes and revolve around the outer periphery of the sun gear 51. The revolution of the sun gear 51 causes the planetary carrier 54 to rotate, and the axle shaft 14, which is spline-connected to the planetary carrier 54, to rotate.

[0034] The planetary reducer 17 is disposed between the transmission shaft 13 and the axle shaft 15. The planetary reducer 17 is housed in the right axle housing 23. The planetary reducer 17 reduces the rotation of the transmission shaft 13 and transmits it to the axle shaft 15. The planetary reducer 17 has a configuration similar to that of the planetary reducer 16. The planetary reducer 17 has a sun gear 56, a ring gear 57, a plurality of planetary gears 58, and a planet carrier 59. The sun gear 56 is fixed to an end of the transmission shaft 13. The ring gear 57 is formed on the inner peripheral surface of the right axle housing 23, radially outside the sun gear 56. The plurality of planetary gears 58 are disposed between the sun gear 56 and the ring gear 57. Each of the planetary gears 58 meshes with the sun gear 56 and the ring gear 57. The planetary carrier 59 rotatably supports the plurality of planetary gears 58. The planetary carrier 59 is splined to an end of the axle shaft 15.

[0035] (Shroud 18) The shroud 18 covers the lower part of the bevel gear 32 of the differential 11. Fig. 3 is a perspective view showing the configuration of the portion of the axle device 1 to the right of the shroud 18. In Fig. 3, the upper side of the differential body 21 is omitted to show the internal configuration. Fig. 4 is a perspective view showing the shroud 18. Fig. 5 is a cross-sectional view taken along line AA' in Fig. 1.

[0036] By covering the lower part of the bevel gear 32 with the shroud 18, the lubricating oil inside the shroud 18 can be scraped out by the rotation of the bevel gear 32, for example, during high-speed driving, thereby reducing the stirring resistance of the bevel gear 32.

[0037] 3 and 5, the shroud 18 is disposed on the inner circumferential surface of the lower portion 21d of the differential body 21. The shroud 18 has a left side surface 61, a right side surface 62, a first circumferential surface 63, a second circumferential surface 64, and a connecting surface 65, as shown in FIG.

[0038] The left side surface 61 is disposed perpendicular to the left-right direction. As shown in FIG. 2, the left side surface 61 is disposed on the left direction L side of the bevel gear 32 and the differential case 31. The left side surface 61 is fan-shaped. A radial outer peripheral end 61a of the left side surface 61 is curved so as to protrude downward along the bevel gear 32. As shown in FIG. 2 and FIG. 3, a radial inner peripheral end 61b of the left side surface 61 is curved so as not to interfere with the differential case 31. The inner peripheral end 61b is curved so as to protrude downward. The inner peripheral end 61b is disposed with a slight gap between it and the differential case 31 in the up-down direction.

[0039] The right side surface 62 is disposed perpendicular to the left-right direction. As shown in FIG. 2, the right side surface 62 is disposed on the right direction R side of the bevel gear 32. The right side surface 62 is fan-shaped. The radial outer peripheral end 62a of the right side surface 62 is curved so as to protrude downward along the bevel gear 32. As shown in FIG. 2 and FIG. 5, the inner peripheral end 62b of the right side surface 62 is curved so as not to interfere with the differential case 31. The inner peripheral end 62b is curved so as to protrude downward. The inner peripheral end 62b is disposed with a slight gap from the differential case 31 in the up-down direction. As shown in FIG. 2, the inner peripheral end 62b of the right side surface 62 is formed lower than the inner peripheral end 61b of the left side surface 61 in the portion facing each other in the left-right direction.

[0040] As shown in Fig. 2, the first circumferential surface 63 is disposed on the radial outside of the differential case 31. The first circumferential surface 63 is curved so as to protrude downward along the outer periphery of the differential case 31. As shown in Fig. 4, the first circumferential surface 63 is disposed from the outer circumferential end 61a of the left side surface 61 toward the right direction R.

[0041] As shown in FIG. 2, the second circumferential surface 64 is disposed on the radial outside of the bevel gear 32. The second circumferential surface 64 is curved along the outer periphery of the bevel gear 32 so as to protrude downward. The second circumferential surface 64 is disposed from the outer periphery end 62a of the right side surface 62 toward the left direction L. The second circumferential surface 64 is disposed on the right direction R side of the first circumferential surface 63. As shown in FIG. 2, at positions opposing each other in the left-right direction, the second circumferential surface 64 is disposed below the first circumferential surface 63.

[0042] The connection surface 65 connects an end of the first circumferential surface 63 on the right side (R) and an end of the second circumferential surface 64 on the left side (L). The connection surface 65 is disposed perpendicular to the left-right direction.

[0043] In this manner, the differential case 31 and a portion of the bevel gear 32 are inserted from above into the space surrounded by the left side surface 61, the right side surface 62, the first circumferential surface 63, the second circumferential surface 64, and the connecting surface 65. As a result, the shroud 18 is disposed so as to cover the lower portion of the bevel gear 32 along the circumferential direction.

[0044] (Temporary holding tank 19) Fig. 6 is an enlarged view of part B in Fig. 1. The temporary storage tank 19 is capable of temporarily storing the lubricating oil scooped up by the bevel gear 32. The temporary storage tank 19 is disposed in the differential body 21. As shown in Fig. 5, the differential body 21 has a lower portion 21d, an upper portion 21e, and a side portion 21f. The upper portion 21e is disposed above the lower portion 21d. The side portion 21f connects the end of the upper portion 21e opposite the drive shaft opening 21a to the end of the lower portion 21d opposite the drive shaft opening 21a. The side portion 21f is disposed parallel to the left-right direction.

[0045] The temporary storage tank 19 is disposed on a side surface portion 21f of the differential body 21 as shown in FIG.

[0046] As shown in Figures 3 and 5, the temporary holding tank 19 has a tank outer part 19a and a tank inner part 19b. The tank outer part 19a is formed from an opening 21g formed in the side part 21f toward the outside. The opening 21g is formed in a rectangular shape. As shown in Figure 3, the tank outer part 19a has a bottom surface 71, a first side surface 72, a second side surface 73, a third side surface 74, and an upper surface 75.

[0047] The bottom surface 71 is disposed from the lower edge of the opening 21g toward the outside. The bottom surface 71 is disposed horizontally. The first side surface 72 is disposed from the edge of the opening 21g on the left direction L side toward the outside. The first side surface 72 is connected to the end of the bottom surface 71 on the left direction L side. The first side surface 72 is disposed perpendicular to the left-right direction. The second side surface 73 is disposed from the edge of the opening 21g on the right direction R side toward the outside. The second side surface 73 is connected to the end of the bottom surface 71 on the right direction R side. The second side surface 73 is disposed perpendicular to the left-right direction. The third side surface 74 is connected to the outer end of the first side surface 72, the outer end of the second side surface 73, and the outer end of the bottom surface 71. The third side surface 74 is disposed opposite the opening 21g. The third side surface 74 is disposed parallel to the left-right direction. The upper surface 75 is disposed from the upper edge of the opening 21g toward the outside. The upper surface 75 is connected to the upper end of the first side surface 72, the upper end of the second side surface 73, and the upper end of the third side surface 74. The upper surface 75 is disposed horizontally.

[0048] As shown in Figs. 3 and 6, the tank inner portion 19b has a first side surface 81, a second side surface 82, a third side surface 83, a fourth side surface 84, a fifth side surface 85, and a bottom surface 86. The first side surface 81 protrudes from the edge of the opening 21g on the left direction L side toward the differential 11 side (inside). The first side surface 81 is disposed perpendicular to the left-right direction. The second side surface 82 extends from the end of the first side surface 81 on the differential 11 side toward the right direction R. The second side surface 82 is disposed parallel to the left-right direction.

[0049] The third side surface 83 extends from the end of the second side surface 82 on the right direction R side toward the differential 11 side. The third side surface 83 is disposed perpendicular to the left-right direction. The fourth side surface 84 extends from the end of the third side surface 83 on the differential 11 side toward the right direction R. The fourth side surface 84 is disposed parallel to the left-right direction. The fifth side surface 85 extends from the end of the fourth side surface 84 on the right direction R side toward the side surface portion 21f and is connected to the side surface portion 21f. The fifth side surface 85 is disposed perpendicular to the left-right direction.

[0050] The bottom surface 86 connects the lower end of the first side surface 81, the lower end of the second side surface 82, the lower end of the third side surface 83, the lower end of the fourth side surface 84, and the lower end of the fifth side surface. The bottom surface 86 is arranged horizontally. As shown in FIG. 5, the bottom surface 86 is arranged lower than the bottom surface 71 of the tank outer side portion 19a. As shown in FIG. 6, a through hole 86a is formed in the bottom surface 86. The through hole 86a is arranged near the corner formed by the fifth side surface 85 and the fourth side surface 84. As shown in FIG. 3, the tank inner side portion 19b has an opening 19c at its upper end. The opening 19c is formed by being surrounded by the upper end of the first side surface 81, the upper end of the second side surface 82, the upper end of the third side surface 83, the upper end of the fourth side surface 84, and the upper end of the fifth side surface 85. As shown in FIG. 5, the edge of the upper end of the opening 21g is arranged above the opening 19c.

[0051] The tank inside portion 19b is formed in an L-shape in a plan view, as shown in Fig. 6. The tank inside portion 19b is disposed radially outside the shroud 18 and further protrudes to the right side of the shroud 18.

[0052] 5, the lubricating oil in the shroud 18 is stirred up by the rotation of the bevel gear 32 (see arrow C) and flows into the temporary holding tank 19 (see arrow D). The lubricating oil that has entered the temporary holding tank 19 passes through the through-hole 86a and falls from the temporary holding tank 19 (see arrow E).

[0053] The size of the through hole 86a is set so that the temporary holding tank 19 can be nearly full at maximum vehicle speed in balance with the amount of lubricating oil scooped up by the rotation of the bevel gear 32 and entering the temporary holding tank 19, thereby minimizing the accumulation of lubricating oil in the temporary holding tank 19.

[0054] (Relationship between the volume of the shroud 18 and the volume of the temporary holding tank 19) 5 shows the oil level H, which is the height of the lubricating oil when the engine is stopped. The oil level H is the height of the lubricating oil when the bevel gear 32 is stopped and no lubricating oil has accumulated in the temporary holding tank 19.

[0055] The lubricating oil capacity V1 of the shroud 18 is the capacity of the lubricating oil in the shroud 18 below the oil level H. Since a part of the differential 11 is inserted into the shroud 18, the lubricating oil is stored in a space S1 (see the dotted parts in Figs. 2 and 6) surrounded by the differential 11 and the shroud 18. The space S1 is below the oil level H and is a space surrounded by the shroud 18, the differential case 31, and the bevel gear 32. The lubricating oil capacity V1 of the shroud 18 is the volume of the space S1 generated between the shroud 18 and the differential 11 below the oil level H (denoted as S1(V1) in Figs. 2 and 6).

[0056] The capacity of the lubricating oil in the shroud 18 is the volume obtained by subtracting the volume of the bevel gear 32 arranged in the inner volume of the shroud 18 below the oil level H and the volume of the differential case 31 arranged in the inner volume of the shroud 18 below the oil level H from the inner volume of the shroud 18 below the oil level H. FIG. 7(a) is a view of the shroud 18 from the right side. FIG. 7(b) is a front view of the shroud 18. The oil level H is shown in FIG. 7(a) and FIG. 7(b). The inner volume of the shroud 18 below the oil level H is the volume surrounded by the face F1 including the left side face 61, the face F2 including the right side face 62, the oil level H, and the bottom face (the first peripheral face 63, the second peripheral face 64, and the connecting face 65). The inner volume of the shroud 18 below the oil level H is shown by hatching in FIG. 7(a) and FIG. 7(b).

[0057] On the other hand, the volume V2 of lubricating oil that can be stored in the temporary holding tank 19 is the volume of the space S2 consisting of the tank outer part 19a and the tank inner part 19b below the height of the upper end of the tank inner part 19b, as shown in Figure 5 (shown as S2(V2) in Figures 5 and 6).

[0058] 8 is a graph showing the change in horsepower loss when the volume V2 of the lubricating oil in the temporary holding tank 19 is changed relative to the volume V1 of the lubricating oil in the shroud 18. The horsepower loss is the horsepower lost in the planetary reducers 16 and 17 due to the stirring resistance.

[0059] The horizontal axis of Fig. 8 indicates the tank capacity ratio (V2 / V1). The vertical axis indicates the rate of change in loss horsepower, which indicates the rate of reduction in loss horsepower based on the loss horsepower when temporary holding tank 19 is not provided. If the loss horsepower when temporary holding tank 19 is not provided is a and the loss horsepower when temporary holding tank 19 is provided is b, then ((ba) / a) x 100(%) is shown on the vertical axis.

[0060] In the axle device 1 of this embodiment, the lubricating oil volume V2 of the temporary holding tank 19 is set to be 70% or more and 130% or less of the lubricating oil volume V1 of the shroud 18. The temporary holding tank 19 and the shroud 18 are formed to satisfy 0.7≦V2 / V1≦1.3.

[0061] 8, when the value of V2 / V1 is smaller than 0.7, horsepower loss increases. On the other hand, when the value of V2 / V1 is larger than 1.3, the amount of lubricating oil stored in the temporary storage tank 19 increases too much, which may reduce the lubricity of the bearing 41. For this reason, in the axle device 1 of this embodiment, by satisfying 0.7≦V2 / V1≦1.3, it is possible to suppress an increase in horsepower loss due to stirring resistance and ensure lubricity.

[0062] It is also more preferable that the volume V2 of the lubricating oil in the temporary storage tank 19 is the same as the volume V1 of the shroud 18. This is because, as shown in Figure 8, this achieves a balanced state between reduction in horsepower loss and lubrication.

[0063] (Features, etc.) As described above, in the axle device 1 of this embodiment, the lubricating oil volume V2 of the temporary holding tank 19 is set to be greater than or equal to 70% and less than or equal to 130% of the lubricating oil volume V1 of the shroud 18, thereby suppressing an increase in horsepower loss due to stirring resistance and ensuring lubrication.

[0064] In the axle device 1 of this embodiment, it is more preferable to set the lubricating oil volume V2 of the temporary storage tank 19 to the same value as the lubricating oil volume V1 of the shroud 18, thereby achieving a balance between reducing horsepower loss and lubrication.

[0065] In the axle device 1 of this embodiment, it is possible to reduce horsepower loss in the planetary reduction gears 16, 17 arranged between the axle shafts 14, 15 and the differential 11, and ensure lubrication.

[0066] In the axle device 1 of this embodiment, lubrication of the bearing 41 arranged between the left axle housing 22 and the axle shaft 14, and the bearing 42 arranged between the right axle housing 23 and the axle shaft 15 can be ensured.

[0067] (Other embodiments) Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.

[0068] (A) In the axle device 1 of the above embodiment, the temporary holding tank 19 has a tank outer portion 19a and a tank inner portion 19b, but this is not limited to such a configuration, and the tank may be formed only on the inside or outside of the differential body 21 as long as 0.7≦V2 / V1≦1.3 is satisfied.

[0069] (B) In the axle device 1 of the above embodiment, the temporary holding tank 19 is arranged to protrude to the right direction R of the bevel gear 32 and the shroud 18, as shown in FIG. 6, but as long as 0.7≦V2 / V1≦1.3 is satisfied, the shape is not limited to this and may be, for example, rectangular in a plan view.

[0070] (C) In the shroud 18 of the above embodiment, as shown in FIG. 2, the inner circumferential end 61b of the left side surface 61 is formed higher than the inner circumferential end 62b of the right side surface 62. However, since the shroud 18 is formed according to the shape of the differential case 31, the heights of the inner circumferential end 61b of the left side surface 61 and the inner circumferential end 62b of the right side surface 62 may be changed as appropriate according to the shape of the differential case 31.

[0071] (D) In the axle device 1 of the above embodiment, as shown in FIG. 6, the shroud 18 and the temporary holding tank 19 are disposed to face each other in the radial direction of the rotation shaft of the bevel gear 32, but the arrangement is not limited to this. [Industrial Applicability]

[0072] The axle device of the present disclosure exhibits the effect of suppressing an increase in stirring resistance and ensuring lubrication, and can be used in work vehicles such as motor graders. [Explanation of symbols]

[0073] 1: Axle device 2: Drive shaft 11: Differential 14: Axle shaft 15: Axle shaft 18: Shroud 19: Temporary holding tank 21: Differential body 32: Bevel gear

Claims

1. An axle shaft, a differential that transmits rotation of a drive shaft driven by an engine to the axle shaft; A differential body that houses the differential; a temporary storage tank disposed in the differential body for temporarily storing lubricating oil scooped up by the differential gears; a shroud disposed in the differential body and covering a lower portion of the gear; The capacity of the lubricating oil in the temporary holding tank is 70% or more and 130% or less of the capacity of the lubricating oil in the shroud below the height of the lubricating oil when the engine is stopped. Axle device.

2. the volume of the lubricating oil in the temporary holding tank is the same as the volume of the lubricating oil in the shroud below the level of the lubricating oil when the engine is stopped; The axle assembly according to claim 1 .

3. the differential gear is a bevel gear meshed with the drive shaft gear, The differential is The bevel gear; a differential case to which the bevel gear is connected and which rotates together with the bevel gear in response to rotation of the drive shaft, The volume of the lubricating oil in the shroud that is equal to or less than the height of the lubricating oil when the engine is stopped is a space surrounded by the shroud, the bevel gear, and the differential case that is equal to or less than the height of the lubricating oil when the engine is stopped. The axle assembly according to claim 1 .

4. A planetary reduction gear is disposed between the differential and the axle shaft. The axle assembly according to claim 1 .

5. an axle housing connected to the differential body and housing the axle shaft; The axle assembly of claim 1 , further comprising a bearing disposed between the axle shaft and the axle housing.

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