JPH08105524A - Lubricant circuit for agricultural tractor - Google Patents

Abstract

PURPOSE: To let lubricant be circulated between a rear transmission case and a front gear transmission case regardless of the attitude of a vehicle, and in spite of running and suspension in running. CONSTITUTION: An oil feed path 33 allows lubricant to naturally flow from a rear transmission case 7 to a front gear transmission case 21. The inlet port 34a of a return oil path 34 is faced to the direction which is not parallel to the rotating axial core 25b of a rotating gear 25, with respect to the circumferential surface of the rotating gear 25 of a front gear transmission 20. By this constitution, as far as the rotating gear 25 is rotated with an engine driven, the return oil path 34 allows lubricant to be returned to the rear transmission case 7 from the front gear transmission case 21 by the pumping action of the rotating gear 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch in which an engine is arranged in a front part of a machine body and a rear mission case having a gear transmission for traveling is arranged in a rear part of the machine body, the clutch being connected to the engine, and the clutch. The present invention relates to an agricultural tractor in which a power take-out portion having a front gear transmission for taking out the rotational output from the engine from a position located at a level lower than the output shaft of the clutch is connected to the rear portion of the engine.

[0002]

2. Description of the Related Art In the above-mentioned agricultural tractor, the front gear transmission has a relatively small size because the front gear transmission only transmits the rotational power of the output shaft of the clutch to the output shaft located at the bottom level of the clutch output shaft. Become a mission. Therefore, even if the lubricating oil is stored in the mission case, only a small amount can be stored, and further, the gears constituting the gear mission rotate at a relatively high speed, which causes the oil temperature to rise quickly. Lubricating oil easily blows out of the blazer. As a technique for supplying lubricating oil while avoiding the occurrence of this trouble, there has been a technique disclosed in, for example, Japanese Utility Model Publication No. 6-8359. In other words, the return oil from the steering valve flows into the case of the front gear transmission to lubricate the gears, and the hydraulic oil collected in the case of the front gear transmission flows back from the front gear transmission case to the rear transmission case through the oil guide pipe. In addition, it is disclosed that the rear transmission case is sucked by the hydraulic pump. That is, when the lubricating oil circulates between the front gear transmission case and the rear transmission case, the lubricating oil flows into the case of the front gear transmission and lubricates the front gear transmission, and moreover, the lubricating oil accumulates in the case. It is easy to avoid that the blazer blows out from the blazer when it is left hot.

[0003]

Conventionally, since oil is naturally returned from the front gear transmission case to the rear transmission case by natural flow, the aircraft is in a forward-raising posture or a large amount of oil is supplied to the front gear transmission.
When the oil level of the CFC gear transmission case becomes higher than the oil level of the rear mission case, oil will return from the front gear transmission case to the rear mission case. As a result, when the vehicle is parked for a long time while the engine is driven, it is difficult for the oil to return from the front gear transmission case to the rear transmission case, and the temperature may easily rise. It is an object of the present invention to lubricate a front gear transmission while making it easier to avoid the blowing out of lubricating oil and a rise in temperature, and at the same time being advantageous in terms of structure and cost. .

[0004]

In order to achieve the object of the lubricating oil circuit of the agricultural tractor according to the present invention, in the one described at the beginning, the rear mission case is lubricated to the mission case of the front gear transmission. In addition to an oil supply passage for supplying oil, a return oil passage for returning lubricating oil from the mission case of the front gear transmission to the rear mission case is provided, and an inlet of the return oil passage in the mission case is defined as the front gear transmission. Is arranged near the peripheral surface of the rotary gear that constitutes the above-mentioned structure, and is opposed to the peripheral surface in a direction not parallel to the rotation axis of the rotary gear. As an oil supply path, return oil and relief oil from various hydraulic devices such as a steering device that is configured to use the lubricating oil in the rear mission case as hydraulic oil is returned to the front gear mission case to return oil to this mission case. It may be implemented by adopting the one to be supplied, but adopting the configuration according to claim 2 is advantageous as follows.

[0005]

When the engine is driven, the front gear transmission is transmitted to rotate the rotary gear. Then, the rotary gear feeds the lubricating oil to the inlet of the return oil passage by the feeding action of the teeth existing on the peripheral surface, and the return oil passage transfers the lubricating oil from the front gear transmission case to the rear transmission case by the feeding action of the rotary gear. return. When the oil supply passage is for a hydraulic device, the hydraulic pump operates to cause oil to return from the front gear transmission case to the rear transmission case when the oil supply passage is a natural flow type. As a result, oil naturally flows from the rear mission case to the front gear transmission case, and in any case, the oil supply passage supplies oil from the rear mission case to the front gear transmission case. When the configuration according to claim 2 is adopted, the oil supply passage supplies oil without an increase in the oil temperature which is likely to occur in the case of the pump type oil supply passage. Furthermore, although the oil is allowed to flow naturally, the oil has a larger passage cross-sectional area than the return oil passage to allow the oil to flow smoothly.

[0006]

The lubricating oil circulates between the rear transmission case and the front gear transmission case by the pumping action of the rotary gear and the feeding action by the return oil passage and the oil feed passage, and the rotary gear rotates. As long as the engine is driven as long as the vehicle is running and stopped, the lubricating oil circulates and flows regardless of the posture of the aircraft, such as rising up or rising up backwards. Lubricating oil does not stay in the front gear transmission case regardless of the attitude of the aircraft or travel stop, so oil temperature rise and blowing can be effectively avoided, and the front gear transmission is effectively lubricated with a large amount of low temperature lubricating oil. I can do it now. By using the rotary gear in the pump,
The structure is simpler and cheaper to obtain than a special pump.

According to the second aspect of the present invention, the oil can be smoothly supplied to the front gear transmission without an increase in the oil temperature. From this aspect as well, the low-temperature lubricating oil can be smoothly supplied to the front gear transmission effectively. Can be lubricated.

[0008]

EXAMPLE As shown in FIG. 1, a front wheel 1 and a rear wheel 2
And a lift arm 3 for connecting a working device such as a rotary tiller (not shown) to a rear part of a self-propelled vehicle including a driving part having an engine E in a front part thereof so as to be vertically movable, and An agricultural tractor is configured by including a power take-out shaft 4 for transmitting power to the articulated work device.

In order to enable driving of the front and rear wheels 1 and 2 and power extraction by the power extraction shaft 4, the rear wheel 2
A rear wheel differential mechanism (not shown) that is transmitted to the vehicle, a traveling gear transmission 5 that transmits power to the rear wheel differential mechanism and the front wheel differential mechanism (not shown), and a power take-off shaft 4.
The work gear transmission 6 that transmits power to the vehicle is housed in the rear transmission case 7 that forms the rear part of the machine body, and the transmission structure is configured as shown in FIGS. 2 and 3.

That is, a power take-out portion A having a clutch 10 connected to an output portion of the engine E, a front gear transmission 20, a housing 11 of the clutch 10, and a case 21 of the front gear transmission 20 connected to the clutch housing 11 is provided. An output shaft 22 is continuously provided in the rear part of the engine E and is arranged at a lower level than the output shaft 12 of the clutch 10 in the front gear transmission 20, and the output shaft 12 of the clutch 10 is linked to the output shaft 22. Three
A traveling hydraulic continuously variable transmission equipped with a single spur gear type rotary gear 23, 24, 25, and an output shaft 22 of the Float gear transmission 20 attached to the front part of the rear mission case 7 by a rotary shaft 30. Input shaft 3 of transmission 31
It is connected to 1a. In other words, the rotary shaft 30 is arranged at the lowest possible level, and the step 32 for getting on and off and for driving is located between the engine E and the rear mission case 7.
In order to make it possible to dispose at a level as low as possible while keeping the flat surface, the rotation output transmitted from the engine E to the clutch 10 and output therefrom is brought to a bottom level than the output shaft 12 of the clutch 10 by the action of the front gear transmission 20. It is taken out from the position where it is located and transmitted from this position to the input shaft 31a of the traveling hydraulic continuously variable transmission 31. Then, the rotation output of the continuously variable transmission 31 is configured to be transmitted to the traveling gear transmission 5, and the rotational force of the input shaft 31a of the continuously variable transmission 31 does not shift and the rotation speed remains unchanged. The input shaft 3 is transmitted so as to be transmitted to the work transmission 6.
1a is connected to the input of the work transmission 6.

As shown in FIG. 2, an inlet 33a opened in the front wall portion of the rear mission case 7 into the case,
An oil supply passage 33 made of pipe for supplying lubricating oil from the rear transmission case 7 to the front gear transmission case 21 and having an outlet 33b opening in the rear wall portion of the front gear transmission case 21, and a front gear transmission. The front gear transmission case 21 is lubricated from the front gear transmission case 21 to the rear transmission case 7 by providing an inlet 34a opening into the case at the bottom wall of the case 21 and an outlet 34b opening into the case at the front wall of the rear mission case 7. A pipe return oil passage 34 for returning oil is provided over both mission cases 7, 21. The standard oil level L of the lubricating oil stored in the rear mission case 7 from the inlet 33a to the outlet 33b of the oil supply passage 33
By placing it at a lower level than
The oil supply passage 33 serves as a non-forced passage for allowing the oil to flow naturally, and the lubricating oil is allowed to naturally flow from the rear mission case 7 into the front gear mission case 21 due to the head difference between the rear mission case 7 and the front gear mission case 21. There is. As clearly shown in FIGS. 3 and 4, the rotary gear 2 in which the inflow port 34a of the return oil passage 34 is located at the lowest level of the three rotary gears 23 to 25 is shown.
5 is arranged near the peripheral surface 25a of No. 5 so as to face the peripheral surface 25a in a direction orthogonal or substantially orthogonal to the rotation axis 25b of the rotary gear 25, and the engine E is driven to rotate. The gear 25 is configured to send the lubricating oil to the inflow port 34a by the feeding action of the teeth existing on the peripheral surface 25a, and further, the outflow port 34b is supplied to the standard oil level L of the internal lubricating oil of the rear transmission case 7. By placing it at a higher level than the return oil passage 34
Serves as a forced flow path for forcibly flowing the oil, and the lubricating oil is returned from the front gear transmission case 21 to the rear transmission case 7 by the pump action of the rotary gear 25. The passage sectional area of the oil supply passage 33 is made larger than the passage sectional area of the return oil passage 34.

That is, the lubricating oil stored in the rear transmission case 7 is supplied to the front gear transmission case 21 to lubricate the front gear transmission 20.
Then, the lubricating oil circulates between the rear transmission case 7 and the front gear transmission case 21 by using the oil supply passage 33 and the return oil passage 34 as circulation oil passages and the rotary gear 25 as a return pump. As long as the engine E is being driven and the rotary gear 25 is rotating, the lubricating oil continues to circulate, and even if the lubricating oil lubricates the front gear transmission 20 and raises the temperature, the front gear transmission case 21 is quickly removed. Returning to the rear mission case 7, the temperature is lowered by mixing with a large amount of lubricating oil in the rear mission case. Further, since the oil supply passage 33 is a non-forced passage and the passage cross-sectional area is larger than that of the return oil passage 34, the oil can smoothly flow into the front gear transmission case 21 without the temperature rising. As a result, the lubricating oil has a relatively low temperature as a whole and flows into the front gear transmission case 21 so as not to delay the delivery by the rotary gear 25 and effectively lubricates.

[Other Embodiment] As shown in the above embodiment, the inflow port 34a of the return oil passage 34 is set to the gear 25 located at the lowest level among the gears forming the front gear transmission 20. If it is made to face at the position located at the bottom of the rotary gear 25, even if the amount of lubricating oil in the front gear transmission case 21 decreases and the oil level decreases,
It is advantageous that the pumping action of the can be used to always recirculate forcibly, but it is possible to face the upper part of the gear located at the lowest level or the gear located at a higher level than the gear located at the lowest level. You may carry out by facing.
Further, as shown in FIG. 5, the peripheral surface 25a of the rotary gear 25 may be faced in a tangential direction. Even in this case, there is no difference in that the rotary gear 25 performs the pumping action of feeding the lubricating oil to the inflow port 34a by the teeth located on the peripheral surface 25a. In short, the pump action of the rotary gear can be obtained by allowing the peripheral surface of the rotary gear to face in a direction that is not parallel to the axis of rotation of the rotary gear.

If a non-forced flow path is adopted as the oil supply path 33 as in the above embodiment, the front gear transmission case 2
1 is advantageous in that oil can be supplied without the temperature rise caused by the supply, but return oil and relief oil are supplied from various hydraulic devices such as a steering device that uses the lubricating oil in the rear transmission case as hydraulic oil. Therefore, an oil passage for supplying lubricating oil to the front gear transmission case 21 may be adopted. Therefore, these are collectively referred to as the oil supply passage 33.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

1] A schematic side view of the entire agricultural tractor

[Fig. 2] Side view of the lubricating oil circuit

FIG. 3 is a sectional view of a front gear transmission.

FIG. 4 is a sectional view showing an inflow port of the return oil passage.

FIG. 5 is a sectional view showing an inflow port of another embodiment return oil passage.

[Explanation of symbols]

 5 Running Gear Transmission 7 Rear Transmission Case 10 Clutch 12 Output Shaft 20 Front Gear Transmission 21 Front Gear Transmission Case 25 Rotating Gear 25a Circumferential Surface 25b Shaft Core 33 Oil Supply Path 34 Return Oil Path 34a Inlet A Power Extraction Section E Engine

Claims (2)

[Claims] 1. An engine (E) is arranged at a front part of the machine body, and a rear mission case (7) having a gear transmission (5) for traveling is arranged at a rear part of the machine body and is connected to the engine (E). The clutch (10) and the rotational output from the clutch (10) are transferred to the clutch (1).
(0) output shaft (12) for output from a position located at a level lower than the output shaft (12) equipped with a power take-out section (A) equipped with a front end of the engine (E) connected to the rear of the engine (E) A lubricating oil circuit for a tractor, comprising an oil supply passage (33) for supplying lubricating oil from the rear transmission case (7) to the transmission case (21) of the front gear transmission (20), and the front gear transmission (33). 20) Mission Case (2
A return oil passage (34) for returning lubricating oil from 1) to the rear mission case (7) is provided, and the mission case (21) of the return oil passage (34).
The inflow port (34a) is located near the peripheral surface (25a) of the rotary gear (25) constituting the front gear transmission (20), and the peripheral surface (25a)
With respect to a), the rotary shaft core (25
The lubricating oil circuit of the agricultural tractor facing in a direction not parallel to b). 2. An oil supply passage (33) extends from the rear transmission case (7) to the front gear transmission case (2).
Lubricating oil for agricultural tractors according to claim 1, which is an oil passage for allowing lubricating oil to naturally flow into (1), and wherein the passage cross-sectional area of this oil supply passage (33) is larger than the passage cross-sectional area of said return oil passage (34). circuit.