JPS6145138A - Transmission gear for tractor - Google Patents

Abstract

PURPOSE:To enable to perform gear shifting without stopping running of a tractor, by a method wherein 2 systems of transmission gears are mounted to a transmission route from an engine, and a gear is shifted by the use of the one transmission gear as driving is effected by the use of the other transmission gear. CONSTITUTION:Two transmission mechanisms, having a synchromesh mechanism and the same structure as each other, are mounted to an output shaft 1 transmitting a power from an engine, and the two transmission mechanisms can be selected by means of clutches 25 and 27. When control of gear shifting is effected, the one clutch 27 is disengaged, a power transmission system on the side of said clutch is brought into a free state, and a power is transmitted to driving wheels through other clutch 25 and a power transmission mechanism on the side of the other clutch. With this, gear shifting is conducted, the clutch 27 is engaged upon completion of gear shifting control and simultaneously the clutch 25 is disengaged, and this enables to perform gear shifting without stopping running of a tractor.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a tractor transmission device that can change the speed of a tractor without stopping the traveling of the tractor.

Technical Background of the Invention and Problems Thereto Conventionally, in agricultural tractors that tow tractors such as plows, when changing gears during work, the tractor must first stop traveling before changing gears, and after changing gears, The tractor is started again. However, if the traction load is large, the wheels may slip, making it impossible to restart the vehicle.

Therefore, it is conceivable to use a synchromesh mechanism in the transmission to change gears while the tractor is running without stopping the tractor, but even in this case, the traveling clutch must be disengaged once when changing gears, and the traction load·
If this is large, the tractor will stop due to clutch disengagement.

As a transmission device that can reliably prevent a tractor from stopping during a gear shift operation, there is one in which a wet multi-disc clutch is provided in each gear and the gears are selectively engaged and engaged using hydraulic pressure.

However, since this transmission uses a hydraulic wet multi-plate clutch, it has drawbacks such as a complicated structure and frequent failures.

In addition, there are various continuously variable transmissions that can reliably prevent the tractor from stopping when changing gears, but none of them have sufficient power transmission efficiency and are not suitable for high-load towing work. It has the drawbacks of being unsuitable and expensive.

Purpose of the Invention The present invention has been made in view of the above points, and uses a simple synchromesh mechanism to simplify the structure and ensure that the tractor stops traveling during gear change operation even when the traction load is large. An object of the present invention is to obtain a transmission device for a tractor that can prevent such problems.

SUMMARY OF THE INVENTION The present invention provides a clutch that can selectively connect and disconnect power from an engine as two output systems, connects two transmission gear devices of the same structure with a synchromesh mechanism to the clutch, and The output shaft to which the passive gears are fixed is constantly connected to two speed change gear devices, and during normal work, power is transmitted from the engine to the output shaft through both speed change gear devices, and the clutch is engaged and engaged during speed change operations. The operation puts one speed change gear device in a free state, continues power transmission to the output shaft via the other speed change gear device, and performs a speed change operation in the speed change gear device in the free state,
After this gear shift operation is completed, the clutch is engaged and engaged to free the other gear gear unit that was transmitting power to the output shaft, and the power is transmitted to the output shaft via the other gear gear unit that was performing the gear shift operation. The tractor is configured so that it can transmit power and change gears without stopping the tractor.

Examples of the invention An embodiment of the present invention will be described based on the drawings.

A plurality of passive gears 2, 3, 4.5 having different numbers of teeth are fixed to the output shaft 1 of the tractor. Two intermediate shafts 6.7 are provided on the outer periphery of the output shaft 1, parallel to the output shaft 1 and symmetrical to the output shaft 1 as shown in FIG.

One of the intermediate shafts 6 is provided with loosely fitted gears 8.9, 10., which are equipped with a plurality of synchromesh mechanisms (not shown) that rotate freely while constantly meshing with the passive gears 2, 3, 4.5. 11 is loosely fitted to the other intermediate shaft 7, and the passive gear 2.3 is similarly fitted on the other intermediate shaft 7.
．． 4.5, loosely fitted gears 12, 13, 14 equipped with a synchronized mesh mechanism (not shown) that constantly meshes with the gears and rotates freely.
．． 15 is loosely fitted. In addition.

The number of teeth of the loose fit gears 8 and 12 that mesh with the passive gear 2 is equal,
Similarly, loosely fitted gears 9, 13. The numbers of teeth of the loose fit gear 10°14 and the loose fit gears 11 and 15 are also determined to be the same.

The intermediate shaft 6 has the loosely fitted gears 8 and 9 in a loosely fitted state.
, 10.11 to the intermediate shaft 6 in an alternative and fixed manner, a connecting member 16.1 consisting of a hub, sleeve, etc., equipped with a synchromesh device (not shown).
7 is provided so as to be slidable and fixed at any position.

Note that the intermediate shaft 7 is also provided with connecting members 18 and 19 provided with a similar synchromesh device (not shown). An engineer gear 21 is fixed to the end of the intermediate shaft 6 on the engine 20 side, and an input gear 22 is fixed to the end of the intermediate shaft 7 on the engine 20 side, and the numbers of teeth of the input gears 21 and 22 are set equally. It is being The intermediate shaft 6, the loosely fitted gears 8°9, 10, 11, the connecting member 16, 17, etc. constitute a first gear change amount vehicle equipment fa23, and the intermediate shaft 7
, loose fit gears 12, 13, 14, 15, connection member 18°1
9 and the like constitute a second speed change gear device 24.

A power take-off shaft 26 is provided to which the power from the engine 20 is connected and disconnected by a clutch 25, and this power take-off shaft 26
A power take-off shaft 28 is provided on the outer periphery of the engine 20 to which power from the engine 20 is connected and disconnected by a clutch 27 . An output gear 29 is fixed to the end of the power take-off shaft 26, and the output gear 29 is always meshed with the input gear 21. An output gear 30 is fixed to the end of the power take-off shaft 28, and the output gear 30 is always meshed with the input gear 22. Note that the numbers of teeth of the output gears 29 and 30 are set to be equal.

Note that the output shaft 1 and the power take-off shaft 26 are inserted into the PT.
An O-axis 31 is provided.

In such a configuration, first, when starting the engine 20, both clutches 25.27 are disengaged, and the connecting member 16.1 is disconnected.
7, 18, and 19 to shift to an arbitrary shift position. For example, when shifting to ■ speed,
By shifting the connecting members 16 and 18, the loosely fitted gear 8 is connected to rotate integrally with the intermediate shaft 6, and the loosely fitted gear 12 is connected so as to rotate integrally with the intermediate shaft 7. When the clutches 25, 27 are connected in this state, the power from the engine 20 is transferred to the power take-off shaft 26, the output gear 29, the input gear 21, the intermediate shaft 6. One power transmission system via a loosely fitted gear 8, a power transmission shaft 28, an output gear 30. input gear 22,
The power is transmitted from the other power transmission system via the intermediate shaft 7 and the loosely fitted gear 12 to the passive gear 2 and the output shaft 1, and the tractor
Start at high speed.

Next, a description will be given of a gear shifting operation of the tractor during traveling. For example, when shifting from the first speed running state to the second speed, one of the clutches 27 is disengaged to make the power transmission system on that side of the clutch 27 free. At this time, power is transmitted to the output shaft 1 by the power transmission system on the other clutch 25 side, and the tractor continues to travel. The connecting member 18 of the power transmission system, which is now in a free state, is shifted and the loosely fitted gear 13 is connected to the intermediate shaft 7 so as to rotate integrally therewith. After this shift operation is completed, by disengaging the clutch 25 and connecting the clutch 27, the power from the engine 20 is transmitted to the output shaft 1 via the power transmission system on the clutch 27 side, and the tractor is shifted to second speed. . In this way, the speed of the tractor is changed without stopping the tractor's walking, and furthermore, the disengagement of the clutch 25 and the engagement of the clutch 27 are carried out continuously and instantaneously, so that the work equipment connected to the tractor has a large amount of traction. Even when a load is applied, clutch 2
It is possible to prevent the tractor from stopping due to the vehicle speed being below 5. After the power transmission system on the clutch 25 side becomes free, the connecting member 16 is shifted to connect the loosely fitted gear 9 to the intermediate shaft 6 so as to rotate together with the intermediate shaft 6, and then the clutch 25 is connected. Thereby, power transmission to the output shaft 1 is performed from both the power transmission system on the clutch 25 side and the power transmission system on the clutch 27 side,
Prepare for the next gear shift operation.

In addition, when stopping the running of the tractor.

Both clutches 25, 27 are disengaged and each connecting member 16, 17, 18, 19 is placed in a neutral position as shown in FIG.

Effects of the Invention As described above, the present invention includes a clutch that can selectively connect and disconnect power from the engine as two output systems, and a synchromesh mechanism that is connected to the clutch and constantly connected to the output shaft. and two speed change gear devices having the same structure, and during a speed change operation, one of the speed change gear devices is set in a free state by engaging and disengaging the clutch, and an arbitrary speed change operation is performed in the speed change gear device that is in the free state, After this shift operation is completed, the clutch is engaged and engaged.

By freeing the speed change gear that was transmitting power to the output shaft and transmitting power to the output shaft via the speed change gear that was in the free state,
It is possible to prevent the tractor from stopping when changing gears so that the work can be continued smoothly, and also to obtain sufficient power transmission efficiency, and because the structure is simple, maintenance and inspection can be easily performed. It has effects such as being able to.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram showing a power transmission system, and FIG. 2 is an explanatory diagram showing the arrangement of an output shaft and an intermediate shaft. 1... Output shaft, 2-5... Passive gear, 2o... Engine, 23.24... Speed change gear device, 25.27.
··clutch

Claims (1)

[Claims] A first speed change gear device equipped with a synchromesh mechanism and equipped with a clutch that can selectively connect and disconnect power from the engine as two output systems; and a second speed change gear device having the same structure as the first speed change gear device. is connected to the clutch and has an output shaft to which a plurality of passive gears are fixed, and this output shaft is always connected to the first speed change gear device and the second speed change gear device. Tractor transmission.