JP5616837B2 - Work vehicle - Google Patents

Description

  The present invention relates to a work vehicle in which a differential mechanism and an output shaft of the differential mechanism are housed in an axle case.

In a work vehicle, conventionally, lubricating oil for lubricating a differential mechanism built in an axle case, a gear provided on an output shaft, and the like is stored at a predetermined liquid level (see, for example, Patent Document 1).
As the differential mechanism is driven, the lubricating oil is agitated and splashed up by the differential mechanism and the gear provided on the output shaft, and scattered in the case.

Japanese Patent Laid-Open No. 11-278074

Therefore, as the liquid level of the lubricating oil in the axle case increases, the stirring resistance of the lubricating oil by the differential mechanism and the gear provided on the output shaft increases, and the driving resistance of the differential mechanism increases.
Further, when the lubricating oil is agitated as the differential mechanism is driven, the oil temperature rises.
For this reason, energy loss occurs due to an increase in driving resistance of the differential mechanism and an increase in oil temperature.
If the level of the lubricating oil is lowered in order to reduce energy loss, there is a risk that insufficient lubrication will occur at the start of driving where there is little adhesion of the lubricating oil.
The present invention has been made in view of the above circumstances, and is intended to provide a work vehicle that is less likely to cause insufficient lubrication at the start of driving of the differential mechanism and has little energy loss during the driving of the differential mechanism. Objective.

According to a first characteristic configuration of the work vehicle according to the present invention, a differential mechanism, an output shaft of the differential mechanism, and a lubricating oil tank are incorporated in an axle case, and the lubricating oil tank contains the lubricating oil in the axle case. An intake hole that can be taken in from the upper part, and an outflow hole that can let the taken-in lubricating oil out from the lower part, the opening area of the outflow hole being set smaller than the opening area of the intake hole, and the lubricating oil A pair of lower tank portions disposed at positions where the output shaft sandwiches the output shaft from the front and rear in the axial direction, and an upper tank portion that communicates the lower tank portions so as to straddle the upper side of the output shaft. The intake tank is formed in the upper tank portion, the outflow hole is formed in the lower tank portion, and when the differential mechanism is stopped, the liquid level of the lubricating oil is the output shaft. It is in the point located above the lower end of .

The work vehicle of this configuration is equipped with a lubricating oil tank, and the lubricating oil tank has an intake hole through which the lubricating oil in the axle case can be taken in from above, and an outflow hole through which the taken lubricating oil can flow out from below. It has.
For this reason, the taken-in lubricating oil can be made to flow out from the lower part of a lubricating oil tank, taking in the lubricating oil splashed up by the drive of the differential mechanism from the upper part of a lubricating oil tank to the said lubricating oil tank.

In addition, since the opening area of the outflow hole is set smaller than the opening area of the intake hole, the outflow amount of the lubricating oil from the outflow hole is made smaller than the intake amount of the lubricating oil from the intake hole, The differential mechanism can be driven in a state where the difference is temporarily accumulated in the lubricating oil tank.
For this reason, the level of the lubricating oil in the axle case becomes low during the driving of the differential mechanism, and when the driving of the differential mechanism is stopped, the lubricating oil in the lubricating oil tank gradually enters the axle case from the outflow hole. It flows out and the level of the lubricating oil increases.

Further, the work vehicle of this configuration includes a lower tank in a posture in which the lubricating oil tank straddles the upper side of the output shaft and the pair of lower tank portions disposed at positions where the output shaft is sandwiched from the front and rear in the axial direction. And an upper tank part communicating the parts, an intake hole is formed in the upper tank part, and an outflow hole is formed in the lower tank part.
For this reason, it is easy to arrange a lubricating oil tank having a large capacity by arranging the lubricating oil tank in a space between the output shaft and the axle case so as to surround the output shaft in the circumferential direction.

  Therefore, in the case of a work vehicle of this configuration, a lubricating oil tank with a large capacity can be arranged so that the level of the lubricating oil in the axle case can be increased when the differential mechanism starts to be driven. There is little risk of shortage, and the level of the lubricating oil in the axle case can be lowered while the differential mechanism is being driven. Therefore, an increase in driving resistance and an increase in oil temperature are reduced, resulting in less energy loss.

  A second characteristic configuration of the present invention is that a cross-sectional shape along a direction orthogonal to the output shaft on the upper surface side of the upper tank portion is formed into a shape along the inner peripheral surface of the axle case.

  With this configuration, it is easy to install a lubricating oil tank having a larger tank capacity by disposing the upper surface side of the upper tank portion so as to be substantially along the inner surface of the axle case.

According to a third characteristic configuration of the present invention, the inner end of the lubricating oil tank in the vehicle width direction is located outside the outer end of the differential mechanism in the vehicle width direction. The lubricating oil tank is disposed so as to be close to the outer end portion in the width direction, and the intake hole is formed toward the differential mechanism.

  If it is this structure, it will be easy to take in the lubricating oil splashed up by the differential mechanism in a lubricating oil tank efficiently.

It is a side view which shows a tractor. It is an expanded view which shows the structure of a front-wheel drive system. (A) is a perspective view which shows a lubricating oil tank. (B) is the IIIb-IIIb arrow directional cross-sectional view in FIG.3 (c) of a front axle case. (C) is the IIIc-IIIc arrow directional cross-sectional view in FIG.3 (b) of a front axle case. It is explanatory drawing explaining a mode that lubricating oil is taken in into a lubricating oil tank from a taking-in hole. (A), (b) is sectional drawing which shows the change of the liquid level of the lubricating oil in a front axle case and a lubricating oil tank.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an agricultural tractor which is an example of a work vehicle having a front axle case A as an axle case according to the present invention.
The tractor transmits the power of the engine 1 mounted on the front of the fuselage to the transmission installed in the transmission case 2 at the rear of the fuselage, drives the rear wheels 3 with the output from the transmission, and from the transmission case 2 to the fuselage. The front wheels 5 are driven via the front wheel drive shaft 4 that protrudes toward the front side.
In the figure, 6 is a steering handle, 7 is a steering seat, 8 is a hydraulically driven lift arm, and 9 is a rear PTO shaft output from the transmission.

FIG. 2 is a development view showing the structure of the front wheel drive system for convenience.
The right side of the boundary line L in the figure shows the transmission structure in a plan view, and the left side of the boundary line L shows the transmission structure when the airframe is viewed from the front-rear direction.

  As shown in FIG. 2, the power of the front wheel drive shaft 4 is transmitted to the differential mechanism 10. The power transmitted to the differential mechanism 10 is transmitted to the upper and lower transmission shafts 13 in the left and right deceleration drive cases 12 via the left and right output shafts 11 and further to the wheel shaft via the deceleration bevel gear mechanism 14. 15 to drive and rotate the front wheel 5.

The differential mechanism 10 and the left and right output shafts 11 of the differential mechanism 10 are housed in the front axle case A.
The front axle case A is attached to the lower part of the fuselage by a pair of front and rear mounting brackets 17 via mounting bosses 16 extending toward the front side and the rear side of the fuselage at the center in the left-right direction. It has been.

  The boss portion 16 is held by a cylindrical shaft portion 17 a provided on the bracket 17 so as to be rotatable around a rotation axis X along the front-rear direction of the body at the center in the left-right direction of the body. The rotation axis X is supported as a rolling axis so that it can be rolled right and left.

  The rolling shaft core (rotating shaft core) X coincides with the shaft core of the input shaft 20 provided at the shaft end with the bevel gear portion 19 that meshes with the input bevel gear 18 of the differential mechanism 10. On the other hand, the front end of the front wheel drive shaft 4 is connected to the rolling shaft core X concentrically.

The differential mechanism 10 housed in the front axle case A is displaced to one side from the rolling shaft core X, and both left and right ends thereof are supported by the differential bearing 21.
The output shafts 11 extending from the differential mechanism 10 to the left and right sides are respectively integrated with a transmission bevel gear 23 supported by support bearings 22 near the entrances of the left and right speed reduction drive cases 12. It is connected by a rotating mechanism so that it can be inserted and removed.

  Inside the front axle case A, as shown in FIG. 2, a lubricating oil 24 for lubricating gears and the like provided on the differential mechanism 10 and the output shaft 11 is provided at a predetermined liquid level La (the shaft of the output shaft 11). A lubricating oil tank 25 for temporarily storing lubricating oil 24 is housed on both the left and right sides sandwiching the differential mechanism 10.

The front axle case A communicates with the left and right deceleration drive cases 12, and therefore the lubricant oil 24 is also stored in the deceleration drive case 12 at the same liquid level La.
The lubricating oil tank 25 is provided on both the left and right sides of the front axle case A with the differential mechanism 10 interposed therebetween. In FIG. 2, only one lubricating oil tank 25 is shown, but the other lubricating oil tank 25 is provided. Are also provided in the same manner, and the description thereof is omitted.

  As shown in FIG. 3, the lubricating oil tank 25 has a pair of lower tank portions 26 disposed at positions where the output shaft 11 is sandwiched from the front and rear in the axial direction, and a posture that straddles the upper side of the output shaft 11. It is formed in a downward U-shape including an upper tank portion 27 that communicates the side tank portions 26 with each other.

  The lubricating oil tank 25 is configured to be long horizontally in the left-right direction along the front axle case A, and is located near the differential mechanism 10 in an upper space in the front axle case A formed on the laterally outer side of the differential mechanism 10. To the front end of the front axle case A in a lateral orientation extending from the vicinity of the outer end of the front axle case A, and connected to the inner upper portion of the front axle case A by a connector B.

  The upper surface of the upper tank portion 27 has a center plate portion 28 disposed substantially horizontally along the output shaft 11 at the center in the direction orthogonal to the output shaft 11, and both side edge portions of the center plate portion 28 along the output shaft 11. And an inclined plate portion 29 extending so as to become lower as the distance from the central plate portion 28 increases, and a cross-sectional shape along the direction perpendicular to the output shaft 11 on the upper surface side of the upper tank portion 27 is formed. The front axle case A is formed in a shape along the inner peripheral surface.

  The upper tank portion 27 is formed with a plurality of (three in this embodiment) intake holes 30 (30a, 30b) capable of taking the lubricating oil 24 in the front axle case A from above, and the lower tank portion. Each of 26 is formed with a plurality of (three in this embodiment) outflow holes 31 through which the taken lubricating oil 24 can flow out from the lower part.

The intake holes 30 are formed on the upper surface side of the upper tank portion 27 and the left and right end plate portions 32 that block both longitudinal ends of the output shaft 11.
On the upper surface side of the upper tank portion 27, rectangular first intake holes 30 a in a long plan view along the output shaft 11 are formed in series across both inclined plate portions 29, and the end plate portions 32 are respectively A rectangular second intake hole 30b that is long in the horizontal direction along the direction orthogonal to the output shaft 11 is formed.

The first intake hole 30a is formed to be shifted to the differential mechanism 10 side, and a portion of the central plate portion 28 on the side away from the differential mechanism 10 with the first intake hole 30a interposed therebetween is defined as a front axle case. The left and right attachment portions C formed on the upper part of A are fixed with bolts as a pair of left and right connectors B.
Of the second intake hole 30b, a second intake hole 30c formed in the end plate portion 32 near the differential mechanism 10 side is formed toward the differential mechanism 10 side.

  As shown in FIG. 4, the intake holes 30 (30 a, 30 b) are dropped after the lubricating oil 24 scattered in the front axle case A is directly attached to the upper inner surface of the front axle case A or the like. Capture in the state.

  Each of the outflow holes 31 is formed in the bottom plate 33 of the lower tank portion 26 (the bottom plate of the lubricating oil tank 25) in a portion on the side away from the differential mechanism 10 along the output shaft 11 with a space therebetween. Has been.

  The sum of the opening areas of the plurality (three) of the outflow holes 31 is larger than the sum of the opening areas of the plurality (three) of the intake holes 30 (the first intake hole 30a and the two second intake holes 30b). The difference between the intake amount of the lubricating oil 24 from the intake hole 30 and the outflow amount of the lubricating oil 24 from the outflow hole 31 can be temporarily stored in the lubricating oil tank 25 by setting it to be small. It is.

  Therefore, when the differential mechanism 10 is not driven, as shown in FIG. 5A, the in-case liquid level La, which is the liquid level of the lubricating oil 24 in the front axle case A, and the lubricating oil tank The liquid level Lb in the tank which is the liquid level of the lubricating oil 24 in the tank 25 is maintained at the same level.

  Further, during the driving of the differential mechanism 10, as shown in FIG. 5B, when the liquid level in the case becomes low and the liquid level in the tank becomes high at the same time, the driving of the differential mechanism 10 is stopped. Then, the lubricating oil 24 in the lubricating oil tank 25 gradually flows out from the outflow hole 31 into the front axle case A, and as shown in FIG. 5A, the liquid level in the case La and the liquid level Lb in the tank. Are maintained at the same level.

[Other Embodiments]
1. In the above embodiment, a single intake hole 30 or a single outflow hole 31 may be provided in the lubricating oil tank 25.
2. In the above embodiment, a configuration in which the second intake hole 30 b is eliminated and only the first intake hole 30 a is provided on the upper surface side of the upper tank portion 27 may be adopted as the intake hole 30. A configuration may be adopted in which the insertion hole 30 a is eliminated and only the second intake hole 30 b is provided in the end plate portion 32 of the upper tank portion 27.
3. In the above embodiment, the cross-sectional shape along the direction orthogonal to the output shaft 11 on the upper surface side of the upper tank portion 27 may be formed in an arc shape along the inner peripheral surface of the front axle case A.
4). In the above-described embodiment, the front axle case A includes a lubricating oil tank 25 in which a plurality of first intake holes 30 a are arranged along the longitudinal direction of the output shaft 11 on the upper surface side of the upper tank portion 27. Also good.
5. In the above embodiment, an example in which the lubricating oil tanks 25 are provided on both the left and right sides of the front axle case A has been described. However, the lubricating oil tanks 25 may be provided only on the left and right sides of the front axle case A.
6). In the above embodiment, an example in which the lubricating oil tank 25 is provided in the front axle case of the tractor has been shown. The present invention is applicable not only to the front axle case but also to the rear axle case that supports the rear wheel.

  The present invention can be applied to various work vehicles such as tractors and rice transplanters.

DESCRIPTION OF SYMBOLS 10 Differential mechanism 11 Output shaft 24 Lubricating oil 25 Lubricating oil tank 26 Lower tank part 27 Upper tank part 30 Intake hole 31 Outflow hole A Axle case
La liquid level

Claims (3)

A differential mechanism, an output shaft of the differential mechanism, and a lubricating oil tank are incorporated in the axle case,
The lubricating oil tank includes an intake hole capable of taking in the lubricating oil in the axle case from above, and an outflow hole capable of flowing out the taken lubricating oil from below,
The opening area of the outflow hole is set smaller than the opening area of the intake hole,
The lubricating oil tank communicates between the pair of lower tank portions disposed at positions where the output shaft is sandwiched from the front and rear in the axial direction, and the lower tank portion in a posture straddling the upper side of the output shaft. An upper tank part,
The intake hole is formed in the upper tank part,
The outflow hole is formed in the lower tank portion,
A work vehicle in which a level of the lubricating oil is positioned above a lower end of the output shaft when the differential mechanism is stopped .   The work vehicle according to claim 1, wherein a cross-sectional shape along a direction orthogonal to the output shaft on an upper surface side of the upper tank portion is formed in a shape along an inner peripheral surface of the axle case. The inner end of the lubricating oil tank in the vehicle width direction is closer to the outer end of the differential mechanism in the vehicle width direction than the outer end of the differential mechanism in the vehicle width direction. The lubricating oil tank is arranged,
The work vehicle according to claim 1, wherein the intake hole is formed toward the differential mechanism.

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