JPS6128847B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle transmission that enables switching between forward and backward travel with a simple operation, and also makes it possible to perform work efficiently by keeping the vehicle speed approximately the same when switching between forward and backward travel. This is what I did.

Vehicles such as agricultural tractors require frequent switching between forward and backward movement when performing front loader work or earth removal work, but conventional transmissions have a connection method for only the reverse system that is separate from the forward system. Since the gear lever is configured to be engaged and disengaged by means of a lever, it is not possible to switch between forward and backward movement simply by operating the gear shift lever back and forth, and the operation is extremely complicated. In addition, the vehicle speed was significantly different when moving forward and backward, and the vehicle speed was particularly slow when moving backward, which caused problems in terms of work efficiency.

The present invention is aimed at solving these problems, and its characteristics are that the driving shaft and the driven shaft are mounted parallel to each other, and
A forward gear system and a reverse gear system that span between the driving shaft and the driven shaft are provided adjacent to each other in the axial direction, and the speed ratios of both gear systems are approximately the same, and both gear systems are connected to the driven shaft. A single connecting means for detachably connecting to the driven shaft is provided on the driven shaft so as to be slidable in the axial direction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The figure shows a transmission 1 of an agricultural tractor vehicle. Transmission 1 is installed in series.

The transmission 1 is covered with a clutch housing 2 and a transmission case 3 connected to the rear of the clutch housing 2. The transmission case 3 has a front part, a middle part, and a transmission case 3.
It is detachably divided into rear cases 4, 5, and 6. A differential device 7 is included in the rear case 6 and connected to the rear wheels 8, and a PTO transmission device is included behind the differential device 7, and this device is protruded from the rear surface of the rear case 6. It is connected to the PTO shaft. These rear wheels and the PTO shaft are driven by an engine 9 via the transmission 1.

A flywheel 11 is attached to the rear end of the crankshaft 10 supported by a bearing in the crankcase, and the front end of the PTO main shaft 12 in the longitudinal direction of the shaft center is spline-fitted to the center of the wheel 11, and the rear end of the PTO main shaft 12 is supported by a PTO main shaft rear bearing 13, which is held by a PTO main shaft support 14 that is detachably attached to the rear surface of the intermediate case rear wall 5. In addition, there is a PTO at the rear of the PTO main shaft 12.
The intermediate shaft 15 and the PTO rear shaft 16 are sequentially mounted on the same axis, and the PTO main shaft 12 and the PTO intermediate shaft 15 are connected by a hydraulically operated wet disc clutch.
It is said that it can be freely connected and disconnected by the clutch 17. A PTO shift gear 18 that is slidable in the axial direction is provided at the front end of the PTO rear shaft 16, and the gear 18 releasably connects the PTO rear shaft 16 and the PTO intermediate shaft 15. In the above case, the PTO main shaft 12 is the drive shaft, and the PTO
The intermediate shaft 15 is the driven shaft, and the PTO clutch 17
is located near the dividing end of the rear case 6 forward.

Front and rear main shafts 19 and 20 each having a cylindrical cross-section are fitted in the middle of the PTO main shaft 12 so as to freely rotate, and a disk is disposed between the front end of the front main shaft 19 and the flywheel 11. A main clutch 21 is attached, and the main clutch 21 can be freely connected and disconnected by pressing a clutch pedal (not shown). Further, a main shaft clutch 22 is provided between the front and rear main shafts 19 and 20, which is a hydraulically operated wet disc clutch that can freely connect and disconnect these two shafts 19 and 20. Main shaft one-way clutch 23 that transmits power only to
is provided. Further, a front main shaft gear 24 is fixed to the front main shaft 19, and a rear main shaft gear 25 is fitted onto the front part of the rear main shaft 20 so as to freely rotate. A second main shaft one-way clutch 26 is provided for power transmission.

An intermediate shaft 27 parallel to these shafts 19 and 20 is mounted below the front and rear main shafts 19 and 20, and the first and second intermediate gears 2 are mounted on the intermediate shaft 27.
8 and 29 are fixed to the front and rear main shaft gears 2, respectively.
4 and 25 are always engaged.

In the rear part of the front case 4, first, second, third, and fourth drive gears 30, 3 whose diameters gradually decrease from the front to the rear are arranged on the rear main shaft 20 at predetermined intervals in the axial direction.
1, 32, and 33 are spline-fitted.Meanwhile, below the rear main shaft 20, a first transmission shaft 34 parallel to the axis is mounted. second, third and fourth transmission gears 35;
36, 37, and 38 can rotate freely, and the transmission gear 3
9 is fitted externally with a spline. These first ~
The four speed change gears are always meshed with the corresponding drive gears. Moreover, the first and second transmission gears 3
Connecting bodies 39 and 40 are spline-fitted to the first speed change shaft 34 between the gears 5 and 36 and between the third and fourth speed change gears 37 and 38, respectively. The first and second shifters 41 and 42, which are externally fitted with splines, can be freely engaged and disengaged from the coupling bodies 39 and 40, respectively, and the respective transmission gears, and a four-speed transmission can be selected from the rear main shaft 20 to the first transmission shaft 34. has been done.
The shifters 41 and 42 are made selectively movable in the axial direction by operating shift forks 44 and 45 in conjunction with manual operation of the first speed change lever 43. The rear main shaft 20, the first transmission shaft 34, and a group of gears on these shafts constitute a first transmission 46 capable of shifting in four stages.

Inside the substantially intermediate case 5, a first reduction shaft (driving shaft) 47 having a cylindrical cross section is mounted so as to fit around the PTO main shaft 12, and passive gears are sequentially attached to the first reduction shaft 47 from the front to the rear. 48, the reverse drive gear 49 and the fifth drive gear 50 are integrally molded or spline-fitted, while a second speed change gear is located below the first reduction shaft 47 and coaxially with the first speed change shaft 34. A shaft (driven shaft) 51 is mounted on the shaft, and the second speed change shaft 51
From the front to the rear, the reverse gear 54 is always meshed with the reverse drive gear 49 via the sixth gear 52 and the idler gear 53, and the fifth gear is always meshed with the fifth drive gear 50. 55 are freely rotatable. The idle gear 53 is loosely fitted onto the reverse shaft 56. A second speed reduction shaft 57 having a cylindrical cross section is mounted below the second speed change shaft 51, and a seventh speed change gear 58, which is always meshed with the sixth speed change gear 52, An eighth speed change gear 59 that is integrally molded with the fifth speed change gear 55 and a ninth speed change gear 60 that is always meshed with the fifth speed change gear 55 are integrally molded or spline-fitted. Connecting bodies 61 and 62 are spline-fitted between the transmission gear 39 and the sixth gear tooth 52 and on the second gear shaft 51 between the reverse gear 54 and the fifth gear gear 55, respectively. The third and fourth shifters 6 are externally fitted with splines so as to be slidable in the axial direction.
3 and 64 are provided, and these shifters 63 and 64
are the connecting bodies 61 and 62 and the second transmission shafts 51, respectively.
It can be freely engaged and disengaged from the upper gear. Note that the transmission gear 39 and the passive gear 48 reduce the first reduction gear system 6.
5. The fifth drive gear 50 and the fifth speed change gear 55 connect the second reduction gear system 66, the eighth speed change gear 59 and the ninth speed change gear.
With the speed change gear 60, the third reduction gear system 67 and the seventh
A fourth reduction gear system 68 is constituted by the transmission gear 58 and the sixth transmission gear 52, and these reduction gear systems 55, 56, 57, 58, the second transmission shaft 51, the first and second reduction shafts 47, 57 constitutes a second transmission 69 capable of three-speed shifting. The second transmission 69 includes a reverse gear system 70 consisting of a reverse drive gear 49, an idling gear 53, and a reverse gear 54.
is incorporated, and therefore, when traveling in reverse, the first transmission 46 can shift up to four gears. The shifters 63 and 64 constitute a connecting means, and can be selectively operated by a second shift lever (not shown).
This selection operation causes the second speed change shaft 51 to rotate at high, medium, very low speeds, and backward. The speed ratios of the reduction gear system 66 and the reverse gear system 70 are approximately set.

Thus, when the third shifter 63 is engaged with the transmission gear 39, the second shift shaft 51 is connected to the first shift shaft 34.
It is directly connected to provide high speed rotation. Moreover, if the fourth shifter 64 is engaged with the fifth speed change gear 55, the first speed change shaft 34→transmission gear 39→passive gear 4
8→first reduction shaft 47→fifth drive gear 50→fifth shift gear 55→fourth shifter 64→second shift shaft 51
The power is sequentially transmitted, and the second speed change shaft 51 is given medium speed rotation. Further, when the third shifter 63 is engaged with the sixth speed change gear 52, the first speed change shaft 34→transmission gear 39→passive gear 78→first reduction shaft 47→fifth drive gear 50→fifth speed change gear 55 → 8th speed change gear 59 → 9th speed change gear 60 → 2nd speed change gear 57 → 7th speed change gear 58 → 6th speed change gear 52 → 3rd shifter 63 → 2nd speed change shaft 51. The shaft 51 is given very low speed rotation. Furthermore, when the fourth shifter 64 is engaged with the reverse gear 54, the first shift shaft 34→transmission gear 39→passive gear 4
8→first reduction shaft 47→reverse drive gear 49→idling gear 53→rear gear 54→fourth shifter 64→second
Power is transmitted sequentially to the speed change shaft 51, and the second speed change shaft 51
is driven backwards. At this time, reverse and medium speeds can be changed by simply sliding the fourth shifter 64 back and forth, and therefore, switching between forward and backward is possible by simply operating the second shift lever, for example, in the front and rear directions, and when the front loader is installed. When carrying out loading work, the gear change operation is easy. In addition, since the reverse movement in this case is the same as the medium speed, forward and backward movement can be performed quickly, and work efficiency is significantly improved.

A differential pinion shaft 71 is mounted behind the second speed change shaft 51 on the same axis as the shaft 51, and is caused to move by a large differential gear 73 of the differential device 7 via a differential pinion 72. The differential pinion shaft 71 has a
A tenth speed change gear 74 is spline-fitted, and the tenth speed change gear 74 and the PTO shift gear 18 can be freely engaged and disengaged by sliding the shift gear 18 in the axial direction. Further, a propulsion shaft 75 is inserted through the second deceleration shaft 57 and is coaxial with the shaft 57.
and a third speed change shaft 76 which are coaxially centered behind the propulsion shaft 75, respectively, and an eleventh speed change gear 77 spline-fitted to the third speed change shaft 76 and the tenth speed change gear 77 are spline-fitted to the third speed change shaft 76.
The transmission gear 74 is always meshed with the transmission gear 74.
Further, the propulsion shaft 75 and the third transmission shaft 76 can be connected and connected by a propulsion clutch 78 which is a hydraulically operated wet disc clutch. Note that the propulsion shaft 75 is for front wheel drive.

Note that the first transmission device 46 and the second transmission device 69 may be arranged in reverse order, and although a constant engagement type is illustrated, a selective engagement type may also be used.

It goes without saying that each shift lever is operated along an H-shaped shift guide groove.

In the present invention, the forward and backward gear systems are provided adjacent to each other in the axial direction and are switched by sliding the single coupling means in the axial direction. It is possible to switch between digits and is very easy to operate. Further, since the gear ratios of the forward and backward gear systems are substantially the same, forward and backward movement can be carried out quickly, and together with the above-mentioned operability, work efficiency is significantly improved.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the present invention, in which FIG. 1 is a schematic diagram of the overall configuration, FIG. 2 is a sectional view of a main part, and FIG. 3 is a sectional view of a reverse drive system. DESCRIPTION OF SYMBOLS 1...Transmission, 46...1st transmission, 34...1st speed change shaft, 47...1st speed reduction shaft, 51...2nd speed change shaft, 57...2nd speed change shaft, 6
5...First reduction gear system, 66...Second reduction gear system, 67...Third reduction gear system, 68...Fourth reduction gear system, 69...Second transmission, 70...Reverse gear system .

Claims (1)

[Claims] 1 The driving shaft and driven shaft are mounted parallel to each other, and
A forward gear system and a reverse gear system that span between the driving shaft and the driven shaft are provided adjacent to each other in the axial direction, and the speed ratios of both gear systems are approximately the same, and both gear systems are connected to the driven shaft. A transmission for a vehicle, characterized in that a single coupling means for detachably coupling the driven shaft is provided on the driven shaft so as to be slidable in the axial direction.