JPH0115533Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention arranges the engine, main clutch housing, and transmission case in series in this order, and equips the transmission case with a gear transmission for the traveling system. This invention relates to the power transmission structure of a certain agricultural tractor.

Agricultural tractors often perform work that repeatedly moves back and forth or frequently increases or decreases the forward speed, but if these speed change operations are performed using a gear transmission device that changes speed by gear shifting, the main clutch must be pressed each time. This requires an operation to turn off the light, which is extremely troublesome. Therefore, we introduced a multi-disc hydraulic clutch to the mechanism that switches between forward and backward travel, or even high and low forward speeds, so that it is possible to switch between forward and backward travel by displacing the control valve without the need for switching the main clutch. Furthermore, it is already known and put into practical use that the forward speed can be quickly and easily switched between high and low speeds.

However, in the past, the transmission structure of the hydraulic clutch system was generally very different from that of the system that changed speed by gear shift, so the transmission structure of the hydraulic clutch system adopted a new transmission case and internal gear transmission mechanism. This made it difficult to combine production lines and parts.

In introducing a plurality of multi-plate hydraulic clutches that provide the advantages mentioned above, this idea allows the transmission case and internal gears to be used as much as possible with general gear shift type clutches, thereby reducing the parts and production line. It is possible to reduce costs by making it compatible, and the hydraulic clutch introduction part is compact and has a simple structure.
It is an object of the present invention to provide a novel power transmission structure for an agricultural tractor of the type described at the beginning.

This invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 shows an agricultural tractor equipped with an embodiment of this invention, in which an engine 1, a main clutch housing 2, and a transmission case 3 are arranged in series in this order.
It is formed. The main clutch housing 2 houses a main clutch 4 at its front end 2a, and the transmission case 3 has a transmission case portion 3A located on the front side and a rear housing portion 3B located on the rear side in the illustrated case. It is formed by dividing it into two parts, front and back. A drive shaft 5a for the rear wheel 5 is located on both the left and right sides of the transmission case 3.
is projected from the rear of the transmission case 3, and a PTO shaft 6 is also projected from the rear of the transmission case 3.

As shown in FIG. 2, the transmission case 3 is equipped with a gear transmission 7 for the traveling system. This gear transmission 7 is disposed between a drive system input shaft 8 of the transmission case 3 and a pinion shaft 9, and the pinion shaft 9 is connected to the left and right rear wheel drive shafts 5a via a bevel gear transmission mechanism 10. It is linked to.

Similarly, as shown in FIG. 2, the main clutch housing 2 and transmission case 3 described above are
An intermediate transmission chamber 11 is formed between the two. In this intermediate transmission chamber 11, a plate-shaped fixed bearing body 12 is fixedly installed near the rear end inside the main clutch housing 2, and a support wall portion 3a, 3b are integrally protruded, and these fixed bearing bodies 12 and support wall parts 3
It is formed by dividing the front and rear parts by a and 3b. A driving shaft 13 is provided which is driven by the engine 1 through the main clutch 4, and this driving shaft 13 is supported from within the main clutch housing 2 by a fixed bearing body 12 through a bearing _B1 .
It is thrust into the intermediate transmission chamber 11.

As shown in FIGS. 2 and 3, a plurality of (two) clutch support shafts 1 are provided in the intermediate transmission chamber 11 along the longitudinal direction.
4 and 15 are provided. One of these clutch support shafts 14 is connected to the fixed bearing body 12 and the support wall portion 3.
a, and the other clutch support shaft 15 is rotatably supported by the above-described fixed bearing body 12 and support wall portion 3b via bearings B ₂ , B ₃ or B ₄ , B ₅ at both ends, respectively. . A plurality of gear transmission systems for transmitting power from the drive shaft 13 to the traveling system input shaft 8 of the transmission case 3 using these clutch support shafts 14 and 15 are provided with separate shaft configurations as follows. It is being

That is, as similarly shown in FIGS. 2 and 3, two gears 16 and 17 are fixedly installed on the driving shaft 13 within the intermediate transmission chamber 11. Further, gears 18, 20 rotated by the gear 16 described above and gears 19, 21 rotated by the gear 17 described above are loosely fitted onto each clutch support shaft 14, 15, respectively. As shown in Figure 3a, gears 16, 18, gears 17, 19 and gear 1
6 and 20 are directly engaged with each other,
Further, the gears 17, 21 are
An idle gear 21A that meshes with is provided on a support shaft supported by a fixed bearing body 12 so as to rotate in conjunction with the idle gear 21A. In the illustrated case, the running system input shaft 8 is formed as a hollow shaft and is fitted onto a driving shaft 13 that extends from inside the intermediate transmission chamber 11 into the transmission case 3. Figure 3b
As shown in FIG. 2, one clutch support shaft 14 is interlocked with the drive system input shaft 8 by meshing a gear 22 fixed to its rear end with an input gear 23 fixed to the front end of the drive system input shaft 8. The other clutch support shaft 15 is interlocked with the drive system input shaft 8 by meshing a gear 24 fixed to its rear end with an input gear 25 fixed to the front end of the drive system input shaft 8.

As described above, four sets of gear transmission systems are provided between the driving shaft 13 and the traveling system input shaft 8, and the gear ratio of each gear transmission system is determined by the clutch ratio in each gear transmission system. If the gears 18, 19, 20, 21 loosely fitted onto the support shafts 14, 15 are selectively connected to the clutch support shafts 14, 15, the drive shaft 13 will cause the drive system input shaft 8 to connect to the gears. 16,
Depending on the gear transmission system with gears 18, 22, and 23, the rotation speed is the first forward speed, and the gears 17, 19, and
Depending on the gear transmission system with gears 24 and 25, the rotation speed is the second forward speed, and the gears 16, 20, and 2 are
Depending on the gear transmission system with gears 17, 21A, 25, the rotation speed is the third forward speed, and the gears 17, 21A, 2
The gear transmission system having gears 1, 22, and 23 is set so that each of them can be selectively rotated at the rotation speed of the first reverse speed. In order to selectively couple each gear 18, 19, 20, 21 to the clutch support shaft 14 or 15 on which it is mounted as described above, each of these gears 1
8, 19, 20, 21, each clutch spindle 1
Multi-plate hydraulic clutch 26, 27, 2 on 4, 15
8, 29 are provided, each hydraulic clutch 26, 2
7, 28, and 29 are selectively operated to rotate the driving shaft 13.
It is possible to selectively connect the drive system input shaft 8 and the drive system input shaft 8 at an appropriate gear ratio.

As described above, the transmission system belonging to the traveling system is a plurality (four sets) of gear transmission systems that transmit power from the driving shaft 13 to the traveling system input shaft 8 of the transmission case 3 via the respective clutch support shafts 14 and 15. A gear transmission system including hydraulic clutches 26, 27, 28, 29 for power on/off, which are disposed on the clutch support shafts 14, 15, is provided.
This is further thrust into the transmission case 3 from inside the intermediate transmission chamber 11, and the PTO
It is guided in the direction of axis 6 (FIG. 1).

Next, the hydraulic clutches 26, 27, 28,
To explain the mechanism for supplying hydraulic oil to the clutch 29, as shown in FIGS. 2 and 3 a, each clutch support shaft 14, 15 has three oil passages 30, 31,
Of the oil passages 30, 35, four oil passages 30, 31, 33, 34 are connected to hydraulic clutches 26, 29, 35. The distal end opens into the hydraulic oil chambers 27 and 28 to form an oil passage for supplying hydraulic oil, and the oil is supplied via the oil passages 30, 31, 33, and 34. In addition, the other two oil passages 32 and 35
are hydraulic clutches 26, 29 and hydraulic clutch 2.
7 and 28 are opened at the tips thereof, and are configured as oil passages for supplying lubricating oil.

As shown in Fig. 2, each clutch support shaft 1
The front end portions of 4 and 15 are fitted into through holes drilled in the fixed bearing body 12 and protrude into the fixed bearing body 12, and each clutch support shaft 1
4 and 15, annular hydraulic oil distribution chambers 39 and 40 connected to the oil passages 30 and 31 in the clutch support shaft 14 are provided on the outer peripheral surfaces of the clutch support shaft 14, and annular hydraulic oil distribution chambers 39 and 40 are provided on the outer peripheral surfaces of the clutch support shaft 15. is the oil passage 3 in the support shaft 15.
An annular hydraulic oil distribution chamber 4 connected to 3 and 34
1 and 42, respectively, and these hydraulic oil distribution chambers 39 and 42 are sealed by the inner peripheral surface of the through hole of the fixed bearing body 12. In each of the hydraulic oil distribution chambers 39 and 42, a fixed bearing body 12 is provided.
An oil passage 43 leading to the oil distribution chamber 41 is shown in FIG. As shown in the example, it is left open. Therefore, the fixed bearing body 12 connects the hydraulic oil supply passages 30, 31, 33, 34 drilled in each clutch support shaft 14, 15 to each clutch support shaft 1.
4, 15 constitutes an oil passage joint for connecting to the oil passage outside, and each clutch support shaft 14, 15
The oil passage connection portions for connecting the oil passages 30, 31, 33, 34 inside to the oil passages outside each clutch support shaft 14, 15 are in the hydraulic oil distribution chambers 39, 4 inside the fixed bearing body 12.
0, 41, and 42 are also formed.

The mechanism for connecting the lubricating oil supply oil passages 32, 35 in each clutch support shaft 14, 15 to an external oil passage will be explained.As shown in Figs. An oil passage forming plate 37 is placed along the front surface of the body 12 with a spacer plate 36 made of a thin iron plate sandwiched therebetween.
The fixed bearing body 12 is a connecting portion whose rear end surface also abuts the front end surface of an appropriate number of connecting portions 3c formed protrudingly on the inner surface of the front end portion of the transmission case 3, as shown in FIG. 12a are arranged intermittently to protrude on the back surface of the peripheral edge of the fixed bearing body 12, and are connected to the transmission case 3 by a connecting bolt 38 that is screwed from the oil path forming plate 37 side into a threaded hole in the connecting part 3c. Connection is fixed.

In order to connect the lubricating oil supply oil passage 35 in the clutch support shaft 15 to an external oil passage, the front end of the clutch support shaft 15 is drilled through the oil passage forming plate 37 as shown in FIG. The inside of the through hole is used as a lubricating oil distribution chamber 44, and the oil passage 35 is opened to the lubricating oil distribution chamber 44. A pressure regulating valve (not shown) for setting the hydraulic pressure applied to the hydraulic clutches 26 and 29 is also installed inside the fixed bearing body 12, and the lubricating oil distribution chamber 44 has a relief port for the pressure regulating valve. From fixed bearing body 12
The oil passages guided through the inside and the oil passage forming plate 37 are connected, and a pressure regulating valve 45 for setting the lubricating oil pressure is provided on the front side of the lubricating oil distribution chamber 44. As described above, the oil passage forming plate 37 disposed inside the main clutch housing 2 serves as an oil passage for connecting the oil passage 35 for supplying lubricating oil inside the clutch support shaft 15 to the oil passage outside the clutch support shaft 15. It constitutes a road joint. Similarly, as shown in FIG. 2, a housing 46 is attached to the front surface of the oil passage forming plate 37, and the front end of the clutch support shaft 14 passes through the oil passage forming plate 37 and enters the housing 46. I have it coming. A lubricating oil distribution chamber 47 is formed in the housing 46 whose front end is closed with a cover 46a, and the oil passage 32 in the clutch support shaft 14 is opened into the lubricating oil distribution chamber 47. Lubricating oil distribution chamber 4
Similarly to the lubricating oil distribution chamber 44 at the end of the clutch support shaft 14, 7 is connected to the relief port of the pressure regulating valve for setting the clutch operating oil pressure. Therefore, the main clutch housing 2 is located on the front side of the oil passage forming plate 37.
The housing 46 disposed therein constitutes an oil passage joint for connecting the oil passage 32 for supplying lubricating oil inside the clutch support shaft 14 to an oil passage outside the clutch support shaft 14 .

To briefly explain the configuration of other parts of the illustrated power transmission structure, in FIG.
This is a hydraulic pump for supplying oil to the pumps 6 and 29, and is configured with one half of the housing 46 serving as a pump case and the driving shaft 13 serving as a pump shaft.

In addition, in FIG. 2, 49 indicates the clutch support shaft 14.
A brake disposed at the end of the clutch support shaft 14,
Therefore, the purpose is to selectively brake the rear wheels 5 via the driving system input shaft 8 and the like. That is, the brake 49 is provided with the other half of the housing 46 serving as a brake housing, and has a spring 50.
The housing 46 includes a movable brake plate 52 which is pressed against a fixed brake surface via a piston 51 to brake the support shaft 14.
An oil chamber 53 is formed in which hydraulic pressure is applied to displace the movable brake plate 52 in the opposite direction. The hydraulic pressure for the hydraulic clutches 26 and 29 is applied to the oil chamber 53. Therefore, when the hydraulic action on the full hydraulic clutches 26 and 29 is released by operating the switching valve (not shown), the brake 51 performs a braking action by releasing the hydraulic action on the oil chamber 53 to quickly move the vehicle. This will prevent the vehicle from starting unexpectedly after the fact.

The above-mentioned hydraulic pump 54, switching valve and pressure regulating valve,
Oil distribution chamber 39, 40, 41, 42, 44, 47,
An oil passage for connecting the oil chamber 53 of the brake 49, etc. is formed using the above-described fixed bearing body 12, the spacer plate 36, and the oil passage forming plate 37. 2nd, 4th
In the figure, G ₁ and G ₂ indicate oil grooves provided in the oil passage forming plate 37 and the fixed bearing body 12, respectively, for forming such oil passages, and the oil grooves G ₁ and G ₂
The gaps are appropriately connected by oil holes formed through the gap plate 36.

In order to use the illustrated transmission structure for a four-wheel drive agricultural tractor, the pinion shaft 9 extends forward and extends in front of the oil passage forming plate 37, as shown in FIG. A gear 54 for taking out driving force for the front wheels is fixed to the extending end.

As shown in FIG.
In addition to the transmission gear that also serves as the transmission gear, two transmission gears 55 and 56 are fixedly installed, and transmission gears 57 and 59, which are meshed with the above-mentioned gears 55 and 23, respectively, are loosely fitted onto the pinion shaft 9. A shift gear 58 that can be installed and meshed with the gear 56 is installed by spline fitting. The shift gear 58 includes each transmission gear 57,
Engagement portions 58a and 58b are formed that can mesh with engagement portions 57a and 59a formed at 59. The traveling gear transmission 7 selectively slides and displaces the shift gear 58 on the pinion shaft 9 so that the meshing portion 57
The meshing between the gears 56 and 58 provides the gear ratio of 1st speed, the meshing of the gears 56 and 58 provides the gear ratio of 2nd speed, and the meshing between the meshing portions 58b and 59a provides the gear ratio of 3rd speed. Give each selectively.

The main clutch housing 2 and the transmission case 3 are connected and fixed by a connecting member 60 shown in FIG. In FIG. 2, reference numeral 3d denotes a supporting wall portion that is integrally formed with the rear housing portion 3B in the transmission case 3, and supports the respective rear end sides of the travel system input shaft 8, pinion shaft 9, and drive shaft 13. are doing.

As is clear from the above explanation, the transmission structure of the agricultural tractor of this invention has the engine 1, main clutch housing 2, and transmission case 3 arranged in series in this order, front and back. The transmission structure of an agricultural tractor is equipped with a gear transmission 7 for the traveling system inside the transmission case 3, and there is a transmission structure between the main clutch housing 2 and the transmission case 3.
The front and rear parts are partitioned by a plate-shaped fixed bearing body 12 located on the side of the main clutch housing 3 and supporting walls 3a and 3b integrally protruding from the inner surface of the transmission case 3 near the front end thereof. Intermediate transmission chamber 1
1, and a driving shaft 13 driven by the engine 1 via the main clutch 4 is thrust into the intermediate transmission chamber 11 from within the main clutch housing 2 by bearing on the fixed bearing body 12. A plurality of clutch support shafts 14 and 15 are provided in the chamber 11, which are supported by the fixed bearing body 12 and the support walls 3a and 3b. A plurality of gear transmission systems that transmit power to the drive shaft 13 include gears 16 and 17 fixed to the drive shaft 13 and the clutch support shaft 14,
Gears 18, 19, 20, 21 arranged on 15,
22, 24 and the gear 2 fixed to the drive system input shaft 8
3 and 25 are provided with separate shaft configurations, and in each of these gear transmission systems, multi-plate hydraulic clutches 26, 27, 2 for power input/disconnection are provided on the clutch support shafts 14, 15.
8 and 29, and each clutch support shaft 1
4 and 15 into the fixed bearing body 12 to supply hydraulic oil to the multi-plate hydraulic clutches 26, 27, 28, and 29 on the clutch support shafts 14 and 15. Axis 26, 27, 2
Oil passages 30, 31, 33, 3 drilled in 8, 29
4 to oil passages outside each clutch support shaft 14, 15,
It is characterized by being formed and installed in the fixed bearing body 12, and has the following advantages.

That is, the power transmission structure of the agricultural tractor of this invention uses a plurality of shafts that are different from these shafts 13 and 8 to connect the driving shaft 13 and the traveling system input shaft 8 of the transmission case 3. Clutch support shafts 14 and 15 are provided in the intermediate transmission chamber 11 as described above to constitute a multi-gear transmission system with separate shafts,
Since the hydraulic clutches 26, 27, 28, 29 for power on/off are interposed in such a separate shaft gear transmission system, the traveling transmission system including the hydraulic clutches is connected to the separate shaft gear in the intermediate transmission chamber 11. Depending on the transmission structure, it can be provided with any specification. Moreover, in the intermediate transmission chamber 11 formed between the main clutch housing 2 and the transmission case 3, a plurality of multi-plate hydraulic clutches are mounted on the clutch support shafts 14 and 15, which are separate shafts, as described above. By installing the hydraulic clutch in a manner that does not occupy a large front-to-back width, such as distributing and installing it on the support shafts 14 and 15, a hydraulic clutch is introduced, and an oil passage 30 for supplying hydraulic oil in the clutch support shafts 14 and 15 is installed. , 31, 33, 34 to external oil passages, and are formed and installed in the fixed bearing body 12 that partitions the front end side of the intermediate transmission chamber 11. The proposed transmission structure, in which a multi-plate hydraulic clutch is introduced in a manner in which the longitudinal length of the intermediate transmission chamber 11 for introducing the hydraulic clutch is further compressed, suppresses the enlargement of the transmission mechanism due to the introduction of the hydraulic clutch. , other gear transmission mechanisms etc. can be installed behind the compact clutch introduction part with almost the same specifications as in a type of transmission structure that does not introduce a hydraulic clutch. Therefore, according to this invention, it is now possible to relatively easily construct a transmission structure that uses a hydraulic clutch by using the transmission case and internal gear change mechanism of a transmission structure that does not use a hydraulic clutch. It becomes easy to achieve cost reduction by making the production line and interior parts, such as the processing line and assembly line, and the interior parts of the transmission case of the type that does not introduce a clutch be used together with the production line and interior parts.

Further, in the present transmission structure, a clutch support shaft 14 is provided in a plate-shaped fixed bearing body 12 that partitions the front end side of an intermediate transmission chamber 11 for introducing a hydraulic clutch and supports a driving shaft 13 and a plurality of clutch support shafts 14 and 15 by bearing. ,1
Hydraulic oil supply oil passages 30, 31, 33, 34 in 5
an oil passage connection part 39 for connecting the to an external oil passage;
40, 41, and 42 to serve as a member for forming an oil passage connection part inside the fixed bearing body 12, and to partition the rear end side of the intermediate transmission chamber 11 for introducing the hydraulic clutch. Multiple clutch spindle 1
Since the support walls 3a and 3b that support the bearings 4 and 15 are integrally formed with the transmission case 3, the hydraulic clutch introduction part is not only compactly integrated as described above, but also the same introduction part. The structure of the section has been simplified as much as possible.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of an agricultural tractor equipped with an embodiment of this invention, Fig. 2 is a partially exploded longitudinal sectional side view of the main parts of the same tractor, and Figs. 3a and 3b are, respectively.
FIG. 4 is a schematic diagram showing the gear meshing state of the main parts in the same embodiment, and FIG. 4 is a cross-sectional plan view of only the main parts of the tractor. 1...Engine, 2...Main clutch housing, 3
...Transmission case, 3a, 3b... Support wall part, 4... Main clutch, 6... PTO shaft, 7... Traveling system gear transmission, 8... Traveling system input shaft, 9... Pinion shaft, 11... Intermediate transmission chamber, 12... Fixed bearing body, 13
...Drive shaft, 14,15...Clutch support shaft, 16,1
7... Gear, 18, 19, 20, 21... Gear, 21
A... Idle gear, 22... Gear, 23... Input gear, 24... Gear, 25... Input gear, 26, 27,
28, 29...Multi-plate hydraulic clutch, 30, 31,
33, 34...Oil passage, 39, 40, 41, 42...Hydraulic oil distribution chamber (oil passage connection part), _G1 , _G2 ...Oil groove, _B1 ,
_B2 , _B3 , _B4 , _B5 ...Bearing.

Claims (1)

[Scope of utility model registration request] A transmission structure for an agricultural tractor in which an engine, a main clutch housing, and a transmission case are arranged in series in this order, and a gear transmission for the traveling system is equipped inside the transmission case, Between the main clutch housing and the transmission case, there is provided a plate-shaped fixed bearing body located on the main clutch housing side and a support wall integrally provided on the inner surface of the transmission case near the front end thereof. forming an intermediate transmission chamber partitioned into the front and rear parts, and allowing a driving shaft driven by the engine via the main clutch to be thrust into the intermediate transmission chamber from within the main clutch housing by bearing on the fixed bearing body; A plurality of clutch support shafts are provided in the intermediate transmission chamber, which are supported by the fixed bearing body and the support wall portion, and a plurality of gear transmissions are transmitted from the drive shaft to the travel system input shaft of the transmission case. The system is provided with a separate shaft configuration consisting of a gear fixed to the drive shaft, a gear disposed on the clutch support shaft, and a gear fixed to the travel system input shaft, and each of these gear transmission systems includes a gear disposed on the clutch support shaft. A multi-plate hydraulic clutch for power on/off is provided at the top, and the front end of each clutch support shaft is inserted into the fixed bearing body to supply hydraulic oil to the multi-plate hydraulic clutch on each clutch support shaft. An oil passage connecting portion for connecting an oil passage drilled in each clutch support shaft to an oil passage outside each clutch support shaft is formed and installed in the fixed bearing body.
Agricultural tractor power transmission structure.