JPH0742843Y2 - Agricultural tractor transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a transmission for an agricultural tractor.

2. Description of the Related Art Conventionally, in an agricultural tractor in which a multi-plate clutch is provided in the traveling system transmission path that transmits power from the engine to the drive wheels, the multi-plate clutch malfunctions due to a failure of the power source that operates the multi-plate clutch. In case of such a situation, a gearbox for escape has been exclusively provided so that power can be transmitted from the engine to the drive wheels without using the multi-plate clutch.

Problems to be solved by the invention It is extremely costly to provide a gearbox for escape in case of a failure that may occur very rarely, and the power transmission mechanism becomes large and large as a whole. It's getting complicated.

Means for Solving the Problems Second transmission shaft detachably connected to the first transmission shaft through a slide gear slidably fitted to a first transmission shaft connected to an engine And a power take-out system transmission path in which a PTO take-out shaft is connected to the second transmission shaft, and a traveling system transmission path for transmitting power from the engine to the drive wheels and having a multi-plate clutch in the middle In the agricultural tractor having, the slide connecting the first transmission shaft and the second transmission shaft on a rotary shaft in the traveling system transmission path located on the drive wheel side from the multi-plate clutch. The gear is provided with a gear that meshes with the slide gear located at a position where the connection between the first transmission shaft and the second transmission shaft is released without meshing, and the first gear is engaged when the multi-plate clutch malfunctions. Transmission shaft and above The gear is slidably provided so as to mesh with the slide gear in a state of being connected to the second transmission shaft.

Action By sliding the slide gear to engage with the gear and releasing the connection between the first transmission shaft and the second transmission shaft, the second transmission shaft and the PTO take-out shaft are connected via the traveling system transmission path. The PTO take-out shaft rotates at a speed proportional to the traveling speed of the agricultural tractor. When the multi-plate clutch does not operate properly, the slide gear is slid to connect the first transmission shaft and the second transmission shaft, and then the gear is slid to mesh with the slide gear. As a result, the power from the engine is transmitted to the rotary shaft of the traveling system transmission path via the first transmission shaft, the second transmission shaft, the slide gear, and the gear, and the drive wheels rotate to drive the agricultural tractor. Be seen.

Embodiment An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a power transmission path in an agricultural tractor, which includes a traveling system transmission path 3 for transmitting power from the engine 1 to the rear wheels 2 which are drive wheels, and a power transmission from the engine 1 to the PTO extraction shaft 4. Power transmission system transmission path 5 is provided. In the traveling system transmission path 3, the main clutch 6,
Forward / reverse switching device 7, high / low speed switching device 9 using multi-plate clutch 8, main transmission device 10, auxiliary transmission device 11, creep device 1
2, a drive pinion gear unit 13, a rear wheel differential gear unit 14, and a final reduction gear unit 15 are provided. On the other hand, the power take-off system transmission path 5 is a first transmission shaft directly connected to the engine 1.
16 and a second transmission shaft 17 provided on the same straight line as the transmission shaft 16, and a traveling proportional transmission 18 and a PTO transmission 19 are further provided.

Next, the agricultural tractor is provided with a differential case 20 for accommodating the drive pinion gear portion 13 and the like. Inside the differential case 20, a drive pinion shaft which is a rotary shaft forming a part of the traveling system transmission path 3 is provided. 21 is pivotally supported. Then, on the rear end side of the drive pinion shaft 21, a slide gear 22 forming a part of the traveling proportional transmission 18 is slidably spline-fitted, and on the front end side of the drive pinion shaft 21. Is the creep device 12
A slide gear 23 that constitutes a part of the above is slidably fitted in a spline.

On the other hand, the transmission shafts 16 and 17 are also pivotally supported in the differential case 20 with an axis parallel to the drive pinion shaft 21. A tooth portion 24 is formed at the rear end portion of the transmission shaft 16, and a slide gear 25 is slidably spline-fitted to the tip end side of the transmission shaft 17. Here, a tooth portion 26 that selectively meshes with the tooth portion 24 and a tooth portion 27 that selectively meshes with the slide gear 22 are formed in the slide gear 25. The traveling proportional transmission 18 is configured.

A hydraulic power source take-out device 28 for driving a hydraulic pump (not shown) or the like is connected to the transmission shaft 16, and the drive pinion shaft 21 selectively transmits power to front wheels (not shown). A four-wheel drive take-out device 29 is connected.

In such a structure, when power is taken out from the PTO take-out shaft 4 regardless of the traveling speed of the agricultural tractor, the slide gear 25 is slid forward to release the meshing between the tooth portion 27 and the slide gear 22. With teeth 26 to teeth 24
Bite into. As a result, the power from the engine 2 is transmitted from the transmission shaft 16 to the transmission shaft 17, and is further transmitted to the PTO take-out shaft 4 via the PTO transmission device 19, and the power is taken out from the PTO take-out shaft 4.

Next, when power is taken out from the PTO take-out shaft 4 in proportion to the traveling speed of the agricultural tractor, the slide gear 25 is slid backward to release the meshing between the tooth portions 26 and the tooth portions 24 and Engage 27 with slide gear 22. As a result, the power transmission from the transmission shaft 16 to the transmission shaft 17 is cut off and the power is transmitted from the drive pinion shaft 21 to the transmission shaft 17, and the transmission shaft 17 rotates in proportion to the rotation speed of the drive pinion shaft 21. Rotate by number. Then, the PTO take-out shaft 4 rotates at a rotation speed proportional to the traveling speed of the agricultural tractor.

Here, when the multi-plate clutch 8 malfunctions due to a failure of the drive unit or the like for operating the multi-plate clutch 8 in the high / low speed switching device 9, the traveling system transmission path 3 from the engine 1 to the rear wheel 2 is changed. The power transmission via it becomes impossible. Therefore,
Slide the slide gear 25 forward to move the teeth 26 and teeth 24.
And then the slide gear 22 is slid forward to engage the slide gear 22 with the tooth portion 27. As a result, the power transmitted from the transmission shaft 16 to the transmission shaft 17 is transmitted to the bevel pinion shaft 21 via the slide gears 25 and 22, and the rear wheel 2 is driven. Therefore, the agricultural tractor travels despite the malfunction of the multi-plate clutch 8.

Effect of the Invention Since the invention is configured as described above, when the multi-plate clutch in the traveling system transmission path fails in operation, the slide gear provided in the power take-out system transmission path is slid to move the first gear. By connecting the first transmission shaft and the second transmission shaft, and then sliding the gear fitted to the rotary shaft in the transmission path of the traveling system and meshing with the slide gear It is possible to transmit power from the engine to the drive wheels without going through the drive shaft.In addition, these slide gears and gears are used when rotating the PTO take-out shaft at a rotation speed proportional to the traveling speed of the tractor during normal work. It is used, and it does not provide a dedicated power transmission mechanism in case the multi-plate clutch malfunctions, so it is possible to prevent the production cost from significantly increasing. In addition, the power transmission mechanism can be prevented from becoming large and complicated as a whole.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is an explanatory view showing the entire power transmission path, and FIG. 2 is a vertical side view showing a part of the power transmission path. DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Rear wheel (driving wheel), 3 ... Traveling system transmission path, 4 ... PTO extraction shaft, 5 ... Power extraction system transmission path, 8 ... Multi-plate clutch, 16 ... First transmission shaft, 17 ... Second drive shaft, 21
… Drive pinion shaft (rotating shaft), 22… gear, 25… slide gear

Claims (1)

[Scope of utility model registration request] 1. A first transmission shaft connected to an engine, and a second transmission shaft detachably connected to the first transmission shaft via a slide gear slidably fitted therein. And a power transmission system transmission path in which a PTO extraction shaft is connected to the second transmission shaft, and a traveling system transmission path that transmits power from the engine to the drive wheels and has a multi-plate clutch provided on the way. In the agricultural tractor, on the rotary shaft in the traveling system transmission path located on the drive wheel side from the multi-plate clutch, the slide gear connecting the first transmission shaft and the second transmission shaft is A gear that meshes with the slide gear located at a position where the first transmission shaft and the second transmission shaft are disengaged without meshing is provided, and when the multi-plate clutch malfunctions, the first transmission shaft and With the second transmission shaft Transmission of agricultural tractor, characterized in that said gear is provided slidably to engage with the slide gears of the connecting state.