Axle device

Abstract

To reduce a difference in an oil level between left and right sides.SOLUTION: An axle device is mounted on a vehicle body, and comprises: a transmission shaft that transmits rotational power from a drive source; a differential device including a gear that is rotated about an axis along a left-right direction of the vehicle body by rotation of the transmission shaft; and a housing that houses the differential device, and stores a lubricating oil for lubricating the differential device. The housing has a projection on an inner wall facing an outer periphery of the gear.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Patent Document 1 discloses a lubrication structure for a power transmission device that supplies lubricating oil stored at the bottom of a carrier to one of the bearings. A groove-shaped flow path is formed on the inner wall surface of the carrier to supply the lubricating oil scooped up by a rotating pinion gear to one of the bearings. A protrusion is provided above the flow path to guide the scooped up lubricating oil to the one of the bearings. On the other hand, an axle unit including an axle that transmits the power from the engine through the transmission to the wheels is known. The axle unit includes a drive shaft that transmits the rotational power from the engine, a differential unit including a bevel gear that rotates around an axis along the left-right direction of the vehicle body by the rotation of the drive shaft, and a housing that contains the differential unit and stores lubricating oil for lubricating the differential unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-145409 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an axle device, the rotation of the bevel gear may cause a difference in the height of the lubricating oil liquid surface (hereinafter also referred to as "oil level") between the left and right sides. For example, the oil level is higher on the tooth surface side of the bevel gear than on the opposite side (back side) of the bevel gear tooth surface. In this case, a difference in the cooling capacity of the left and right brakes occurs. For example, in order to eliminate this difference, the oil level may be set to the lower side and the initial oil level may be determined. However, in this case, oil is wasted by the difference in the oil level between the left and right sides, which may result in increased oil costs and oil churning losses. Therefore, there is room for improvement in reducing the difference in the oil level between the left and right sides.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an axle device capable of reducing the difference in oil level between the left and right sides. [Means for solving the problem]

[0006] An axle device according to one embodiment of the present invention is an axle device provided on a vehicle body, and comprises: a transmission shaft that transmits rotational power from a drive source; a differential device including a gear that rotates around an axis along the left-right direction of the vehicle body due to rotation of the transmission shaft; and a housing that accommodates the differential device and stores lubricating oil for lubricating the differential device, the housing having a protrusion on an inner wall facing the outer periphery of the gear. Effect of the Invention

[0007] According to the above aspect, the difference in oil level between the left and right sides can be reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of a vehicle equipped with an axle device according to an embodiment; [Diagram 2] 2 is a rear view of a cross section of the axle device according to the embodiment taken along a vertical plane passing through the center of the axle along the left-right direction of the vehicle body, showing the oil level when the vehicle is stopped. FIG. [Diagram 3]1 is a top view of a cross section of an axle device according to an embodiment taken along a horizontal plane passing through the center of the axle along the left-right direction of the vehicle body, showing the rotation direction of a transmission shaft and the rotation direction of a gear. [Figure 4] 1 is a rear view of a cross section of an axle device according to an embodiment taken along a vertical plane passing through the center of the axle along the left-right direction of the vehicle body, showing a protrusion on an inner wall of a housing. [Diagram 5] FIG. 4 is an enlarged view of a portion of FIG. 3 showing a protrusion on an inner wall of a housing according to the embodiment; [Figure 6] FIG. 4 is a perspective view showing a protrusion on an inner wall of a housing according to the embodiment. [Figure 7] FIG. 13 is a rear view of a cross section of an axle device according to a comparative example taken along a vertical plane passing through the center of the axle along the left-right direction of the vehicle body, showing the oil level during rotation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiment, an axle device mounted on a wheel loader (one example of a vehicle) will be described as an example of the axle device.

[0010] In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," do not only mean such arrangements or states strictly, but also include arrangements or states in which there is a relative displacement with an angle or distance to the extent that the same function can be obtained with a tolerance. In the drawings used in the following description, the scale of each component may be appropriately changed to show each component with a recognizable size.

[0011] <Vehicle> FIG. 1 is a perspective view of a vehicle 100 equipped with an axle device 1 according to an embodiment. As shown in FIG. 1, a vehicle 100 includes a vehicle body 101, a work machine 102, a front traveling device 103, a rear traveling device 104, and a driver's cab 105.

[0012] Hereinafter, the forward direction (front of the vehicle body), backward direction (rear of the vehicle body) and vehicle width direction (left and right direction of the vehicle body) of the vehicle will be referred to as "front of the vehicle (one side in the front-rear direction of the vehicle)", "rear of the vehicle (the other side in the front-rear direction of the vehicle)" and "vehicle width direction". The vehicle width direction may also be referred to as "left side (one side in the vehicle width direction)" or "right side (the other side in the vehicle width direction)". The right side in the forward direction of the vehicle will be referred to as the right side, and the left side in the forward direction of the vehicle will be referred to as the left side. The vehicle up-down direction (up-down direction of the vehicle body), the vehicle upper side (upper side of the vehicle body) and the vehicle lower side (lower side of the vehicle body) of the vehicle will be simply referred to as "up-down direction", "up" and "down". In the example of the figure, the vehicle is placed on a horizontal plane (horizontal ground). The vehicle up-down direction (up-down direction of the vehicle body), the vehicle upper side (upper side of the vehicle body) and the vehicle lower side (lower side of the vehicle body) of the vehicle respectively correspond to the up-down direction (vertical direction), the vertical upper side and the vertical lower side when the vehicle is placed on a horizontal plane. In the following description, the left-hand element may have the suffix L, and the right-hand element may have the suffix R.

[0013] A driver's cab 105 is provided on the upper part of the vehicle body 101. For example, the driver's cab 105 is equipped with a seat for the driver of the vehicle 100 to sit in, levers, pedals, and instruments for various operations.

[0014] The work machine 102 is a machine for excavating or transporting a work target such as earth and sand. The work machine 102 is provided at the front of the vehicle body 101. For example, the work machine 102 includes a boom, a bucket, a bell crank, a lift cylinder, a bucket cylinder, and the like.

[0015] The front traveling device 103 is provided on the front lower part of the vehicle body 101. The front traveling device 103 includes a front wheel that is rotatable around the axis of the front axle 112. The rear traveling device 104 is provided on the lower rear side of the vehicle body 101. The rear traveling device 104 is configured to include rear wheels that are rotatable around the axis of the rear axle 113.

[0016] The vehicle 100 further includes a drive source 110, a transmission 111, a front axle 112, and a rear axle 113. The driving source 110 is mounted on the rear of the vehicle body 101. For example, the driving source 110 is a diesel engine (one example of an engine). For example, the engine is provided with a fuel injection device that injects fuel into the cylinder of the engine, an engine tachometer that measures the engine speed, and the like.

[0017] The transmission 111 changes the speed of the driving force input to an input shaft and outputs it from an output shaft. The input shaft of the transmission 111 is connected to an engine. The output shaft of the transmission 111 is connected to a front axle 112 and a rear axle 113. The transmission 111 transmits the driving force of the engine to the front axle 112 and the rear axle 113.

[0018] The front axle 112 transmits the driving force output by the transmission 111 to the front traveling device 103. This causes the front wheels constituting the front traveling device 103 to rotate in the direction of arrow R1 (the forward rotation direction in the illustrated example). The rear axle 113 transmits the driving force output by the transmission 111 to the rear traveling device 104. This causes the rear wheels constituting the rear traveling device 104 to rotate in the direction of arrow R2 (the forward rotation direction in the illustrated example).

[0019] <Axle device> Fig. 2 is a rear view of a cross section of the axle device 1 according to the embodiment cut by a vertical plane passing through the axle center AC along the left-right direction of the vehicle body, and shows the oil level when the vehicle is stopped. Fig. 3 is a top view of a cross section of the axle device 1 according to the embodiment cut by a horizontal plane passing through the axle center AC along the left-right direction of the vehicle body, and shows the rotation direction of the transmission shaft 2 and the rotation direction of the gear. Fig. 4 is a rear view of a cross section of the axle device 1 according to the embodiment cut by a vertical plane passing through the axle center AC along the left-right direction of the vehicle body, and shows the protrusion 80 of the inner wall 61 of the housing 4. In Figs. 3 and 4, the lubricating oil 5 is omitted. 2 to 4, an axle device 1 is provided on a vehicle body 101. The axle device 1 includes a transmission shaft 2 that transmits rotational power from a drive source 110, a differential device 3 including a gear that rotates about an axis along the left-right direction of the vehicle body by rotation of the transmission shaft 2, and a housing 4 that accommodates the differential device 3 and stores lubricating oil 5 for lubricating the differential device 3. The front axle 112 and the rear axle 113 are an embodiment of the axle unit 1 .

[0020] <Transmission shaft> The transmission shaft 2 extends along the longitudinal direction of the vehicle body. The transmission shaft 2 is disposed at a center BC in the transverse direction of the vehicle body (hereinafter also referred to as the "vehicle body transverse center line BC"). The transmission shaft 2 is connected to an output shaft of a transmission 111. A front end of the transmission shaft 2 is provided with teeth 10 (hereinafter also referred to as the "drive pinion gear 10") that mesh with a bevel gear 20 (an example of a bevel gear that rotates around an axis along the transverse direction of the vehicle body as the transmission shaft 2 rotates).

[0021] <Differential device> The differential device 3 includes a bevel gear 20, axle shafts 30L, 30R, side gears 31L, 31R, differential pinion shaft 40, differential pinion gears 41A, 41B, 41C, 41D, and bearings 50L, 50R. The bevel gear 20 is disposed offset to one side in the left-right direction of the vehicle body with respect to a center BC in the left-right direction of the vehicle body. In the example shown in the figure, the bevel gear 20 is disposed offset to the right with respect to the center BC in the left-right direction of the vehicle body. Note that the arrangement of the bevel gear 20 is not limited to the above and can be changed according to design specifications.

[0022] The bevel gear 20 includes a tooth surface portion 21 having teeth that mesh with the drive pinion gear 10, a back surface portion 22 disposed on the opposite side of the tooth surface portion 21 in the left-right direction of the vehicle body, and a side surface portion 23 disposed on the radially outer side of the bevel gear 20 and connecting the tooth surface portion 21 and the back surface portion 22. For example, a portion (back surface portion) of the tooth surface portion 21 opposite to the side on which the teeth are provided (tooth surface side) is fixed to a differential case 24 described below by a fastening member such as a bolt. In the example shown in the figure, a head 25 of the bolt is disposed on the right side of a case back surface portion 27 of the differential case 24.

[0023] The differential case 24 includes a cylindrical right half 24R that opens in the left-right direction of the vehicle body and supports a portion of the right axle shaft 30R, and a cylindrical left half 24L that opens in the left-right direction of the vehicle body and supports a portion of the left axle shaft 30L. The differential case 24 is connected to the rear portion 22 of the bevel gear 20 and supports portions of the axle shafts 30L, 30R. The outer periphery of the right half 24R is connected to the rear portion 22 of the bevel gear 20. For example, the left and right halves 24L, 24R are fixed to each other by fastening members 26 such as bolts.

[0024] The axle shafts 30L, 30R extend in the left-right direction of the vehicle body. A pair of axle shafts 30L, 30R are provided on the left and right sides. The left and right axle shafts 30L, 30R are arranged coaxially with each other.

[0025] A pair of side gears 31L, 31R are provided on the left and right sides. The side gears 31L, 31R are connected to the inner ends of the axle shafts 30L, 30R in the vehicle width direction. The right axle shaft 30R is supported by the right half body 24R via the right side gear 31R. The left axle shaft 30L is supported by the left half body 24L via the left side gear 31L.

[0026] The differential pinion shaft 40 extends in four directions mutually perpendicular to the radial direction centered on the axle center AC. The differential pinion shaft 40 is disposed offset to the right with respect to the vehicle body left-right center line BC. The differential pinion shaft 40 extends forward-rear, rearward, upward, and downward with the axle center AC as the center. The portions of the differential pinion shaft 40 extending in the forward and rearward directions and the portions extending in the upward and downward directions are disposed coaxially.

[0027] The differential pinion gears 41A, 41B, 41C, and 41D are supported on the differential pinion shaft 40 so as to be rotatable about the differential pinion shaft 40. The differential pinion gears 41A, 41B, 41C, and 41D are supported on portions of the differential pinion shaft 40 that extend forward, rearward, upward, and downward, respectively. The differential pinion gears 41A, 41B, 41C, and 41D mesh with the side gears 31L and 31R.

[0028] A pair of bearings 50L, 50R are provided on the left and right sides. The bearings 50L, 50R are disposed between the differential case 24 and the housing 4. The bearings 50L, 50R rotatably support the differential case 24 to which the bevel gear 20 is connected. The right bearing 50R is disposed between the outer periphery of the right half body 24R and the right inner periphery of the housing 4. The left bearing 50L is disposed between the outer periphery of the left half body 24L and the left inner periphery of the housing 4.

[0029] For example, when the transmission shaft 2 rotates in the direction of the arrow J1 (the forward rotation direction in the illustrated example), the bevel gear 20 rotates in the direction of the arrow J2 (the forward rotation direction in the illustrated example). Then, the side gears 31L, 31R and the axle shafts 30L, 30R rotate together with the rotation of the bevel gear 20. For example, when the vehicle 100 is traveling straight ahead and there is no speed difference (difference in rotation number) between the left and right wheels, the left and right side gears 31L, 31R and the axle shafts 30L, 30R rotate at the same speed.

[0030] On the other hand, when a load is applied to one of the left and right side gears 31L, 31R (for example, when one is fixed), the differential pinion gears 41A, 41B, 41C, 41D rotate while causing the other side gear 31L, 31R to rotate extra. For example, when a speed difference (difference in rotation speed) occurs between the left and right wheels when the vehicle 100 turns a corner, this speed difference can be absorbed.

[0031] <Housing> The housing 4 is a front housing located at the front side in the longitudinal direction of the vehicle body. The housing 4 is formed in a cylindrical shape along the transverse direction of the vehicle body. The housing 4 has an internal space 60 that houses the differential device 3. A portion of the housing 4 that houses the bevel gear 20 bulges outward in the radial direction more than a portion that houses the axle shafts 30L, 30R. In a cross-sectional view of the figure, an inner wall 61 of the portion of the housing 4 that houses the bevel gear 20 is curved toward the front side.

[0032] As shown in Fig. 2, lubricating oil 5 is stored in the internal space 60 of the housing 4. In the example shown in the figure, the initial liquid level S1 of the lubricating oil 5 before the bevel gear 20 rotates (hereinafter also referred to as the "initial oil level S1") is located along the central axis of the axle shafts 30L, 30R. In the example shown in the figure, the initial oil level S1 is located between the upper edges of the axle shafts 30L, 30R and the axle center AC. Note that the initial oil level S1 is not limited to the above and can be changed according to design specifications.

[0033] <Shroud> 2 and 3, the axle device 1 further includes shrouds 65, 66 that guide the lubricating oil 5 that flows around the bevel gear 20 as the bevel gear 20 rotates. The shrouds 65, 66 are disposed with a gap between them and the inner wall 61 of the housing 4. The shrouds 65, 66 include a plate-shaped portion that is aligned with the rotation direction of the bevel gear 20.

[0034] In the illustrated example, a pair of shrouds 65, 66 are provided via the bevel gear 20. The pair of shrouds 65, 66 includes a tooth surface side shroud 65 arranged with a gap between it and the tooth surface portion 21 of the bevel gear 20, and a back surface side shroud 66 arranged with a gap between it and the case back surface portion 27 of the differential case 24. Note that the configuration of the shrouds 65, 66 is not limited to the above, and can be changed according to design specifications.

[0035] <Brakes> The axle device 1 further includes wet multi-plate brakes 70L, 70R at the outer ends in the left-right direction of the vehicle body. A pair of brakes 70L, 70R are provided on the left and right sides. The brakes 70L, 70R are disposed between the outer ends in the vehicle width direction of the axle shafts 30L, 30R and the final gears 71L, 71R. For example, the rotation of the engine, which is shifted by the transmission 111, is finally decelerated by the final gears 71L, 71R and transmitted to the tires.

[0036] At least a portion of the brakes 70L, 70R is immersed in the lubricating oil 5. For example, at the initial oil level S1, about half of the brakes 70L, 70R may be immersed in the lubricating oil 5. Note that the manner in which the brakes 70L, 70R are immersed in the lubricating oil 5 is not limited to the above and can be changed according to design specifications.

[0037] <Protrusion> Fig. 5 is a diagram showing the protrusion 80 on the inner wall 61 of the housing 4 according to the embodiment, and is an enlarged diagram of a part of Fig. 3. Fig. 6 is a perspective view showing the protrusion 80 on the inner wall 61 of the housing 4 according to the embodiment. In Fig. 6, the inner wall 61 (front inner wall 61) of the housing 4 on which the protrusion 80 is provided is not shown. 5 and 6, the housing 4 has a protrusion 80 on an inner wall 61 that faces the outer periphery of the bevel gear 20. The protrusion 80 is provided on the front inner wall 61 of the front housing.

[0038] The protrusion 80 protrudes from the front inner wall 61 of the housing 4 toward the outer periphery of the bevel gear 20. For example, the protrusion 80 may be formed integrally with the front inner wall 61 of the housing 4 using the same member. In this case, for example, the protrusion 80 may be a raised portion protruding from a part of the housing 4. Note that the protrusion 80 is not limited to being a raised portion, and may be formed using a member (plate-shaped member) different from the front inner wall 61 of the housing 4. In this case, for example, the plate-shaped member forming the protrusion 80 may be fixed to the front inner wall 61 of the housing 4 by welding or the like. For example, the form of the protrusion 80 is not limited to the above and can be changed according to design specifications.

[0039] 4 and 5, when viewed from the vehicle body longitudinal direction, a part of the outer shape of the protrusion 80 overlaps with the center BC in the vehicle body transverse direction. In the example of the figure, when viewed from the vehicle body longitudinal direction, a part of the outer shape of the protrusion 80 overlaps with the outer end of the bevel gear 20 in the vehicle body transverse direction. In the example of the figure, when the vehicle body 101 is tilted forward by 6 degrees downward in the vehicle body longitudinal direction, a part of the outer shape of the protrusion 80 overlaps with the liquid level S2 of the lubricating oil 5 (hereinafter also referred to as "oil level S2 when tilted forward"). The oil level S2 when tilted forward is located higher on the vehicle body than the initial oil level S1.

[0040] 2 and 3, when viewed from the front-rear direction of the vehicle body, a portion of the protrusion 80 overlaps with the transmission shaft 2. At least a portion of the protrusion 80 is immersed in the lubricating oil 5. For example, at the initial oil level S1, approximately half of the protrusion 80 may be immersed in the lubricating oil 5. Note that the manner in which the protrusion 80 is immersed in the lubricating oil 5 is not limited to the above and can be changed according to design specifications.

[0041] 5 and 6, the size of the gap G between the protrusion 80 and the bevel gear 20 is 5 mm or more and 10 mm or less. The gap G between the protrusion 80 and the bevel gear 20 corresponds to the minimum distance between the protrusion 80 and the bevel gear 20. In the example shown in the figure, a recess 81 is formed in a portion of the protrusion 80 facing the side surface portion 23 of the bevel gear 20. For example, the bottom surface of the recess 81 is disposed with a uniform gap G along the side surface portion 23 of the bevel gear 20 in the rotational direction and the axial direction of the bevel gear 20.

[0042] 3 and 4, when viewed from the front-rear direction of the vehicle body, a part of the outer shape of the protrusion 80 is inclined so as to approach the axle center AC from the tooth surface side toward the back surface side of the bevel gear 20. The axle center AC corresponds to the centers of the axle shafts 30L, 30R.

[0043] When viewed from the vehicle body longitudinal direction, at least a part of the outer shape of the projection 80 overlaps with the outer shape of a triangle including two sides V1, V2 that incline from the upper and lower sides in the vertical direction of the vehicle body toward the axle center AC as they move from the tooth surface side to the back surface side of the bevel gear 20, and one side V3 that extends along the vehicle body lateral center line BC. In the example shown in the figure, when viewed from the vehicle body longitudinal direction, a part of the outer shape of the projection 80 overlaps with the outer shape of an equilateral triangle with one vertex on the axle center AC.

[0044] 4 and 5 together, when viewed from the vehicle body fore-and-aft direction, a part of the outer shape of the protrusion 80 overlaps with the shroud 65. In the example of the figures, when viewed from the vehicle body fore-and-aft direction, a part of the outer shape of the protrusion 80 overlaps with the tooth surface side shroud 65. In the example of the figures, a groove 82 is formed in the portion of the protrusion 80 that overlaps with the tooth surface side shroud 65 when viewed from the vehicle body fore-and-aft direction.

[0045] On the other hand, the outer shape of the projection 80 does not overlap with the rear shroud 66 when viewed from the front-rear direction of the vehicle body. In the example shown in the figure, the right end of the projection 80 is disposed on the inside of the rear shroud 66 in the left-right direction of the vehicle body. For example, a notch may be formed in the right end of the projection 80 to provide a predetermined distance from the rear shroud 66. For example, the right end of the projection 80 may be set at a position overlapping with the head 25 of a bolt disposed on the right side of the case rear portion 27 when viewed from the front-rear direction of the vehicle body.

[0046] For example, if a part of the contour of the projection 80 overlaps with the contour of the above-mentioned equilateral triangle when viewed from the front-rear direction of the vehicle body, the contour of the projection 80 may be set by the following steps (1) to (6). (1) The right end of the projection 80 is set at a position overlapping with the head 25 of the bolt located on the right side of the case rear portion 27 when viewed from the front-rear direction of the vehicle body. (2) The left end of the protrusion 80 is set at a position overlapping with the center BC in the transverse direction of the vehicle body when viewed from the front-rear direction of the vehicle body. (3) A portion of side V1 of the outer shape of protrusion 80, which slopes from the upper side in the vertical direction of the vehicle body toward the axle center AC as it moves from the tooth surface side to the back surface side of the bevel gear 20, is set at a position that overlaps with the oil level S2 when tilted forward. (4) When viewed from the front-rear direction of the vehicle body, the angle between the side V3 (side along the vertical direction of the vehicle body) along the left end of the projection 80 in (2) above and the side V1 in (3) above is set to 60 degrees. (5) When viewed from the fore-and-aft direction of the vehicle body, side V2 of the outer shape of protrusion 80 inclines from the lower side in the vertical direction of the vehicle body toward the axle center AC as it moves from the tooth surface side to the back surface side of bevel gear 20. Side V2 is set at a position that is linearly symmetrical to side V1 of (4) above, with the axle center AC as the axis of symmetry. (6) The portion of the projection 80 facing the side surface 23 of the bevel gear 20 is spaced from the side surface 23 of the bevel gear 20 by a gap G of about 10 mm. The procedure for setting the outer shape of the protrusion 80 is not limited to the above, and can be changed according to design specifications.

[0047] <Action and effect> As described above, the axle device 1 of this embodiment is provided on a vehicle body 101. The axle device 1 includes the transmission shaft 2 that transmits rotational power from the drive source 110, the differential device 3 including the bevel gear 20 that rotates about an axis along the left-right direction of the vehicle body by rotation of the transmission shaft 2, and the housing 4 that accommodates the differential device 3 and stores the lubricating oil 5 for lubricating the differential device 3. The housing 4 includes a protrusion 80 on an inner wall 61 that faces the outer periphery of the bevel gear 20. For example, as shown in FIG. 7, in the axle device 1X, the rotation of the bevel gear 20X may cause a difference in the height (oil level) of the liquid surface of the lubricating oil 5 between the left and right. For example, the oil level is higher on the tooth surface side of the bevel gear 20X than on the opposite side (back side) of the tooth surface of the bevel gear 20X. In this case, a difference in the cooling capacity of the left and right brakes occurs. For example, in order to eliminate this difference, the oil level may be adjusted to the lower side and the initial oil level may be determined. However, in this case, the oil is wasted by the difference in the oil level between the left and right, which may result in increased oil costs and oil churning loss. In contrast, according to the present configuration, by providing the protrusions 80 on the inner wall 61 of the housing 4 facing the outer periphery of the bevel gear 20, the gap G between the inner wall 61 of the housing 4 and the outer periphery of the bevel gear 20 can be narrowed by the protrusions 80. Therefore, the flow rate of the oil flowing around the bevel gear 20 due to the rotation of the bevel gear 20 can be increased by the throttling effect of the protrusions 80. This makes it possible to increase the flow rate of the oil flowing toward the back side of the bevel gear 20 rather than the tooth surface side (for example, the oil flowing in the direction of the arrow in FIG. 6). Therefore, the flow rate of the oil flowing from the side with a high oil level to the side with a low oil level can be increased by the rotation of the bevel gear 20. Therefore, the difference in the oil level between the left and right sides can be reduced.

[0048] In this embodiment, when viewed from the vehicle body longitudinal direction, a part of the outer shape of the projection 80 overlaps with the center BC in the vehicle body transverse direction. For example, if the contour of the protrusion 80 extends too far in the direction of the tooth surface side of the bevel gear 20 relative to the center BC in the left-right direction of the vehicle body as viewed from the front-rear direction of the vehicle body, it will obstruct the flow of oil from the tooth surface side to the back side of the bevel gear 20. In contrast, with this configuration, a part of the contour of the protrusion 80 overlaps with the center BC in the left-right direction of the vehicle body as viewed from the front-rear direction of the vehicle body, thereby making it possible to avoid a situation in which the flow of oil is obstructed from the tooth surface side to the back side of the bevel gear 20.

[0049] In this embodiment, when viewed from the front-rear direction of the vehicle body, a part of the outer shape of the projection 80 overlaps with the outer end of the bevel gear 20 in the left-right direction of the vehicle body. According to this configuration, it is possible to prevent the outer shape of the projection 80 from becoming larger than necessary.

[0050] In this embodiment, when the vehicle body 101 is tilted forward by 6 degrees with respect to the vehicle body longitudinal direction, a part of the outer shape of the projection 80 overlaps with the liquid surface S2 of the lubricating oil 5. According to this configuration, even when the vehicle body 101 is tilted forward by 6 degrees downward relative to the front-rear direction of the vehicle body, the flow rate of oil flowing around the bevel gear 20 due to the rotation of the bevel gear 20 can be increased by the throttling effect of the protrusions 80. For example, even when the vehicle 100 is traveling downhill, the difference in oil level between the left and right sides can be reduced.

[0051] In this embodiment, a portion of the projection 80 overlaps with the transmission shaft 2 when viewed from the front-rear direction of the vehicle body. According to this configuration, the flow rate of oil flowing around the bevel gear 20 due to the rotation of the bevel gear 20 accompanying the rotation of the transmission shaft 2 can be more effectively increased by the throttling effect of the protrusions 80.

[0052] In this embodiment, the housing 4 is a front housing disposed at the front side in the vehicle front-rear direction. The protrusion 80 is provided on a front inner wall 61 of the front housing. According to this configuration, the difference in oil level between the left and right sides in the internal space 60 of the front housing can be reduced.

[0053] In this embodiment, at least a portion of the protrusion 80 is immersed in the lubricating oil 5 . According to this configuration, the flow rate of oil flowing around the bevel gear 20 due to the rotation of the bevel gear 20 can be more effectively increased by the throttling effect of the projections 80.

[0054] In this embodiment, the size of the gap G between the projection 80 and the bevel gear 20 is not less than 5 mm and not more than 10 mm. For example, if the size of the gap G between the protrusion 80 and the bevel gear 20 is less than 5 mm, the gap G will be too small, and there is a high possibility that the necessary dimensions cannot be secured, taking into consideration the rotational variation of the bevel gear 20, the manufacturing variation of the housing 4, and the adjustment allowance during assembly of the differential device 3. On the other hand, if the size of the gap G between the protrusion 80 and the bevel gear 20 exceeds 10 mm, there is a high possibility that the squeezing effect of the protrusion 80 cannot be sufficiently obtained. In contrast, according to the present configuration, the size of the gap G between the protrusion 80 and the bevel gear 20 is 5 mm or more and 10 mm or less, so that the above-mentioned necessary dimensions can be secured and the squeezing effect of the protrusion 80 can be sufficiently obtained.

[0055] In this embodiment, when viewed from the vehicle body front-rear direction, a part of the outer shape of the projection 80 is inclined so as to approach the axle center AC from the tooth surface side of the bevel gear 20 toward the back surface side. With this configuration, compared to a case where the outer shape of the protrusion 80 extends uniformly in the left-right direction of the vehicle body from the tooth surface side to the back surface side of the bevel gear 20, the oil flowing around the bevel gear 20 due to the rotation of the bevel gear 20 can be more easily guided from the tooth surface side to the back surface side of the bevel gear 20. Therefore, the difference in oil level between the left and right sides can be more effectively reduced.

[0056] In this embodiment, when viewed from the fore-and-aft direction of the vehicle body, at least a portion of the outer shape of the protrusion 80 overlaps with the outer shape of a triangle that includes two sides V1, V2 that incline from the upper and lower sides in the vertical direction of the vehicle body toward the axle center AC as they move from the tooth surface side toward the back surface side of the bevel gear 20, and one side V3 that runs along the left-right center line BC of the vehicle body. According to this configuration, the oil flowing around the bevel gear 20 due to each of the forward and reverse rotations of the bevel gear 20 can be easily guided from the tooth surface side to the back surface side of the bevel gear 20. Therefore, the difference in oil level between the left and right sides can be more effectively reduced. For example, the difference in oil level between the left and right sides can be more effectively reduced when the vehicle 100 is traveling forward and backward.

[0057] In this embodiment, the axle device 1 further includes a shroud 65 that guides the lubricating oil 5 that flows around the bevel gear 20 as the bevel gear 20 rotates. A part of the outer shape of the projection 80 overlaps with the shroud 65 when viewed from the front-rear direction of the vehicle body. According to this configuration, the flow rate of the oil that flows around the bevel gear 20 as the bevel gear 20 rotates and is guided by the shroud 65 can be more effectively increased by the throttling effect of the projections 80.

[0058] In this embodiment, the axle device 1 further includes wet multi-plate brakes 70L, 70R on the outer end sides in the left-right direction of the vehicle body. At least a portion of the brakes 70L, 70R is immersed in the lubricating oil 5. According to this configuration, the brakes 70L, 70R can be cooled by the lubricating oil 5, so that the braking performance of the brakes 70L, 70R can be maintained.

[0059] <Modification> In the above embodiment, an example has been described in which a part of the outer shape of the protrusion overlaps with the center in the left-right direction of the vehicle body when viewed from the front-rear direction of the vehicle body, but this is not limited thereto. For example, the entire outer shape of the protrusion does not have to overlap with the center in the left-right direction of the vehicle body when viewed from the front-rear direction of the vehicle body. For example, the outer shape of the protrusion may extend long in the direction of the tooth surface side of the bevel gear with respect to the center in the left-right direction of the vehicle body when viewed from the front-rear direction of the vehicle body. For example, the arrangement of the outer shape of the protrusion with respect to the center in the left-right direction of the vehicle body can be changed according to the design specifications.

[0060] In the above embodiment, an example has been described in which a part of the outer shape of the protrusion overlaps with the outer end of the bevel gear in the left-right direction of the vehicle body when viewed from the front-rear direction of the vehicle body, but this is not limited thereto. For example, the entire outer shape of the protrusion does not have to overlap with the outer end of the bevel gear in the left-right direction of the vehicle body when viewed from the front-rear direction of the vehicle body. For example, the arrangement of the outer shape of the protrusion relative to the outer end of the bevel gear in the left-right direction of the vehicle body can be changed according to design specifications.

[0061] In the above embodiment, an example has been described in which a part of the outer shape of the protrusion overlaps with the surface of the lubricating oil when the vehicle body is tilted forward by 6 degrees with respect to the vehicle body longitudinal direction, but this is not limited thereto. For example, when the vehicle body is tilted forward by 6 degrees with respect to the vehicle body longitudinal direction, the entire outer shape of the protrusion does not have to overlap with the surface of the lubricating oil. For example, the arrangement of the outer shape of the protrusion with respect to the surface of the lubricating oil when the vehicle body is tilted forward can be changed according to the design specifications.

[0062] In the above embodiment, an example has been described in which a part of the protrusion overlaps with the transmission shaft when viewed from the front-rear direction of the vehicle body, but this is not limited thereto. For example, the entire protrusion does not need to overlap with the transmission shaft when viewed from the front-rear direction of the vehicle body. For example, the arrangement of the outer shape of the protrusion with respect to the transmission shaft can be changed according to the design specifications.

[0063] In the above-described embodiment, the housing is a front housing arranged at the front side in the vehicle front-rear direction, and the protrusion is provided on the front inner wall of the front housing, but this is not limited to the above. For example, the housing may be a rear housing arranged at the rear side in the vehicle front-rear direction, and the protrusion may be provided on the rear inner wall of the rear housing. For example, the protrusion may be provided on the front inner wall of the front housing and / or the rear inner wall of the rear housing. For example, the manner in which the protrusion is provided on the front housing and the rear housing can be changed according to design specifications.

[0064] In the above embodiment, an example is described in which at least a portion of the protrusion is immersed in the lubricating oil, but this is not limited thereto. For example, the entire protrusion does not need to be immersed in the lubricating oil. For example, the manner in which the protrusion is immersed in the lubricating oil can be changed according to the design specifications.

[0065] In the above embodiment, the size of the gap between the protrusion and the bevel gear is 5 mm or more and 10 mm or less, but this is not limited thereto. For example, the size of the gap between the protrusion and the bevel gear may be less than 5 mm or more than 10 mm. For example, the size of the gap between the protrusion and the bevel gear may be changed according to design specifications.

[0066] In the above embodiment, an example has been described in which a part of the outer shape of the protrusion is inclined so as to approach the center of the axle as it moves from the tooth surface side to the back surface side of the bevel gear when viewed from the front-rear direction of the vehicle body, but this is not limited to this. For example, the outer shape of the protrusion may extend uniformly in the left-right direction of the vehicle body from the tooth surface side to the back surface side of the bevel gear. For example, the inclination mode of the outer shape of the protrusion with respect to the center of the axle can be changed according to the design specifications.

[0067] In the above embodiment, an example was given in which at least a part of the outer shape of the protrusion, as viewed from the front-rear direction of the vehicle body, overlaps with the outer shape of a triangle including two sides that incline from the upper and lower sides of the vehicle body vertical direction toward the center of the axle as they move from the tooth surface side to the back side of the bevel gear, and one side along the vehicle body left-right center line, but this is not limited to the above. For example, as viewed from the front-rear direction of the vehicle body, the entire outer shape of the protrusion does not have to overlap with the above triangle. For example, as viewed from the front-rear direction of the vehicle body, the outer shape of the protrusion may be a polygon such as a rectangle or a pentagon, a curved outer shape such as a circle, an ellipse, or an oval, an outer shape including straight lines and curves, or an outer shape that is a combination of these. For example, the aspect of the outer shape of the protrusion can be changed according to the design specifications.

[0068] In the above-described embodiment, the axle device further includes a shroud that guides lubricating oil that flows around the bevel gear as the bevel gear rotates, and an example has been described in which a portion of the outer shape of the protrusion overlaps with the shroud when viewed from the front-rear direction of the vehicle body, but this is not limited thereto. For example, the entire outer shape of the protrusion does not have to overlap with the shroud when viewed from the front-rear direction of the vehicle body. For example, the axle device does not have to include a shroud. For example, the arrangement of the outer shape of the protrusion relative to the shroud and / or the installation of the shroud can be changed according to design specifications.

[0069] In the above-described embodiment, the axle device further includes a wet multi-plate brake on the outer end side in the left-right direction of the vehicle body, and at least a portion of the brake is immersed in lubricating oil, but this is not limited to the above. For example, the entire brake does not need to be immersed in lubricating oil. For example, at least a portion of the brake may be immersed in an oil other than the above-mentioned lubricating oil. For example, the axle device may not include the above-mentioned brake. For example, the axle device may include a brake other than the wet multi-plate type. For example, the manner in which the brake is immersed in lubricating oil and / or the manner in which the brake is installed can be changed according to design specifications.

[0070] In the above-described embodiment, the axle device transmits the force from the diesel engine, which is the driving source, through the transmission to the wheels, but is not limited thereto. For example, the driving source may be an engine other than a diesel engine. For example, the axle device may transmit rotational power from a power source other than an engine to the wheels. For example, the aspect of the driving source may be changed according to the design specifications.

[0071] In the above-described embodiment, the axle device is described as being mounted on a wheel loader, but the present invention is not limited thereto. For example, the axle device may be mounted on other work vehicles such as an excavator, a bulldozer, a dump truck, etc. For example, the form of the vehicle on which the axle device is mounted may be changed according to design specifications.

[0072] In the above embodiment, the gear that rotates around an axis along the left-right direction of the vehicle body by the rotation of the transmission shaft is a bevel gear, but this is not limited to this. For example, the gear that rotates around an axis along the left-right direction of the vehicle body by the rotation of the transmission shaft may be configured to include other gears such as a spur gear, a helical gear, a screw gear, a double helical gear, a spherical gear, etc. For example, the configuration of the gear that rotates around an axis along the left-right direction of the vehicle body by the rotation of the transmission shaft can be changed according to the design specifications.

[0073] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and additions, omissions, substitutions, and other modifications of the configuration are possible without departing from the spirit of the present invention, and the above-described embodiments can also be combined as appropriate.

[0074] (Appendix 1) An axle device provided on a vehicle body, A transmission shaft that transmits rotational power from a drive source; a differential device including a gear that rotates about an axis along the left-right direction of the vehicle body by rotation of the transmission shaft; a housing that accommodates the differential device and stores lubricating oil for lubricating the differential device, The housing has a protrusion on an inner wall facing an outer periphery of the gear. Axle device.

[0075] (Appendix 2) When viewed from the front-rear direction of the vehicle body, a part of the outer shape of the protrusion overlaps with the center of the vehicle body in the left-right direction. 2. An axle arrangement as described in claim 1.

[0076] (Appendix 3) When viewed from the vehicle body front-rear direction, a part of an outer shape of the protrusion overlaps with an outer end of the gear in the vehicle body left-right direction. 3. An axle arrangement as described in claim 2.

[0077] (Appendix 4) When the vehicle body is tilted forward by 6 degrees with respect to the vehicle body longitudinal direction, a part of the outer shape of the protrusion overlaps with the liquid surface of the lubricating oil. 4. An axle arrangement as described in claim 3.

[0078] (Appendix 5) When viewed from the front-rear direction of the vehicle body, a portion of the protrusion overlaps with the transmission shaft. 5. An axle device according to any one of claims 1 to 4.

[0079] (Appendix 6) the housing is a front housing disposed at a front side in a vehicle body longitudinal direction, or a rear housing disposed at a rear side in the vehicle body longitudinal direction, The protrusion is provided on a front inner wall of the front housing or a rear inner wall of the rear housing. 6. An axle device according to any one of claims 1 to 5.

[0080] (Appendix 7) At least a portion of the protrusion is immersed in the lubricating oil. 7. An axle device according to any one of claims 1 to 6.

[0081] (Appendix 8) The size of the gap between the protrusion and the gear is 5 mm or more and 10 mm or less. 8. An axle device according to any one of claims 1 to 7.

[0082] (Appendix 9) When viewed from the front-rear direction of the vehicle body, a part of an outer shape of the protrusion is inclined so as to approach the center of the axle from a tooth surface side of the gear toward a back surface side. 9. An axle device according to any one of claims 1 to 8.

[0083] (Appendix 10) When viewed from the front-rear direction of the vehicle body, at least a part of the outer shape of the protrusion overlaps with the outer shape of a triangle including two sides that incline from the upper and lower sides in the vertical direction of the vehicle body toward the center of the axle as they move from the tooth surface side to the back side of the gear, and one side that runs along the left-right center line of the vehicle body. 10. The axle device of claim 9.

[0084] (Appendix 11) a shroud that guides the lubricating oil that flows around the gear due to rotation of the gear, When viewed from the front-rear direction of the vehicle body, a part of the outer shape of the protrusion overlaps with the shroud. 11. An axle device according to any one of claims 1 to 10.

[0085] (Appendix 12) Further, a wet multi-plate brake is provided at an outer end side in the left-right direction of the vehicle body, At least a portion of the brake is immersed in the lubricating oil. 12. An axle device according to any one of claims 1 to 11. [Explanation of symbols]

[0086] 1...Axle device, 2...Transmission shaft, 3...Differential device, 4...Housing, 5...Lubricant, 20...Bevel gear (gear that rotates around an axis along the left-right direction of the vehicle body by rotation of the transmission shaft), 25...Bolt head (outer end of gear in the left-right direction of the vehicle body), 61...Inner wall, 65...Tooth surface side shroud (shroud), 70L, 70R...Brake, 80...Protrusion, 101...Vehicle body, 110...Drive source, AC...Axle center, BC...Vehicle left-right center line (center in the left-right direction of the vehicle body), G...Gap between protrusion and gear, S1, S2...Lubricant level, V1, V2, V3...Sides included in the outer shape of a triangle

Claims

1. An axle device provided on a vehicle body, A transmission shaft that transmits rotational power from a drive source; a differential device including a gear that rotates about an axis along the left-right direction of the vehicle body by rotation of the transmission shaft; a housing that accommodates the differential device and stores lubricating oil for lubricating the differential device, The housing has a protrusion on an inner wall facing an outer periphery of the gear. Axle device.

2. When viewed from the front-rear direction of the vehicle body, a part of the outer shape of the protrusion overlaps with the center of the vehicle body in the left-right direction.

2. The axle assembly of claim 1.

3. When viewed from the vehicle body front-rear direction, a part of an outer shape of the protrusion overlaps with an outer end of the gear in the vehicle body left-right direction.

3. The axle assembly of claim 2.

4. When the vehicle body is tilted forward by 6 degrees with respect to the vehicle body longitudinal direction, a part of the outer shape of the protrusion overlaps with the liquid surface of the lubricating oil.

4. The axle assembly of claim 3.

5. When viewed from the front-rear direction of the vehicle body, a portion of the protrusion overlaps with the transmission shaft. An axle arrangement as claimed in any one of claims 1 to 4.

6. the housing is a front housing disposed at a front side in a vehicle body longitudinal direction, or a rear housing disposed at a rear side in the vehicle body longitudinal direction, The protrusion is provided on a front inner wall of the front housing or a rear inner wall of the rear housing. An axle arrangement as claimed in any one of claims 1 to 4.

7. At least a portion of the protrusion is immersed in the lubricating oil. An axle arrangement as claimed in any one of claims 1 to 4.

8. The size of the gap between the protrusion and the gear is 5 mm or more and 10 mm or less. An axle arrangement as claimed in any one of claims 1 to 4.

9. When viewed from the front-rear direction of the vehicle body, a part of an outer shape of the protrusion is inclined so as to approach the center of the axle from a tooth surface side of the gear toward a back surface side. An axle arrangement as claimed in any one of claims 1 to 4.

10. When viewed from the front-rear direction of the vehicle body, at least a part of the outer shape of the protrusion overlaps with the outer shape of a triangle including two sides that incline from the upper and lower sides in the vertical direction of the vehicle body toward the center of the axle as they move from the tooth surface side to the back surface side of the gear, and one side that extends along the left-right center line of the vehicle body.

10. The axle assembly of claim 9.

11. a shroud that guides the lubricating oil that flows around the gear due to rotation of the gear, When viewed from the front-rear direction of the vehicle body, a part of the outer shape of the protrusion overlaps with the shroud. An axle arrangement as claimed in any one of claims 1 to 4.

12. Further, a wet multi-plate brake is provided at an outer end side in the left-right direction of the vehicle body, At least a portion of the brake is immersed in the lubricating oil. An axle arrangement as claimed in any one of claims 1 to 4.

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