JPS5921319Y2 - Agricultural tractor travel gear structure - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a traveling transmission structure for an agricultural tractor.

In order to change the traveling speed of a tractor, a main speed change system has a first speed change shaft that is gear-coupled with an input shaft, and a shift gear group that can be selectively interlocked with a gear group that is fixed to the first speed change shaft. a second shaft, a transmission gear to an auxiliary transmission system which is loosely fitted to the second shaft for main transmission and constantly engaged with one of the gear groups of the first shaft for transmission; , a latch capable of switching between a state in which power from the transmission gear is transmitted to an output gear of an auxiliary transmission system that is always engaged with one of the gear groups of the second shaft for main transmission and a non-transmission state; one of the shift gears of the second shaft for main transmission is engaged with the gear of the first shaft for transmission, and the power from the input shaft is transmitted to the traveling wheels via the main transmission transmission system. and the state of
By engaging and operating a clutch of the auxiliary transmission system, the power from the input shaft can be transmitted to the traveling wheels via the auxiliary transmission system, and the main transmission system and the auxiliary transmission system can be selected. By using the gearbox repeatedly, it is possible to obtain a large number of speed change states corresponding to various types of work.

However, conventionally, when the main transmission shift gear is in the transmission shift position, this gear and the output gear of the auxiliary transmission system are in a disengaged state. There is a problem in that it is difficult to engage the main transmission shift gear with the output gear in order to transmit power to the output gear.

In other words, when engaging the main transmission shift gear with the output gear, disengage the clutch of the auxiliary transmission system and operate it in a neutral idle state to prevent damage to the gear, and then The stopped main transmission shift gear will be brought into engagement, but at this time, the relative rotational position of both gears may deviate from the state suitable for engagement.
It is troublesome to first drive the auxiliary transmission system or the main transmission system and set the relative rotational position of both gears to a state suitable for occlusion, and it is difficult to set the relative rotational position of both gears to a state suitable for occlusion. Since it is uncertain whether the output gear or the main transmission shift gear will stop at the rotational position after being driven, there is a risk that the process will have to be repeated many times.

The present invention was made keeping in mind the above actual situation,
In the traveling transmission structure of an agricultural tractor having the structure described above,
A shift gear engaged with the output gear of the auxiliary transmission system,
At least one of the two gears is configured to have a wide width so that the shift gear meshes with the output gear of the auxiliary transmission system even when the shift gear meshes with the gear of the first shifting shaft.

In other words, when operating the main transmission shift gear to the transmission shift position, the auxiliary transmission system is placed in a neutral idle state, so even if the main transmission shift gear and the output gear of the auxiliary transmission system are always engaged, the auxiliary transmission We focused on the fact that driving the system in reverse causes some power loss, but it is not a major problem.Since both gears are always interlocked, we solved the above-mentioned problem and changed the speed change state using the auxiliary transmission system. It has become possible to perform the operation quickly and easily, and according to the present invention, the desired purpose can be achieved by a simple improvement of configuring at least one of the main transmission shift gear and the output gear to be wider. Therefore, it can be easily implemented without significantly improving the conventional structure.

Embodiments of the present invention will be described in detail below with reference to illustrative drawings.

The figure shows a transmission case 1 of an agricultural tractor and a traveling transmission structure installed in an auxiliary transmission case 7 detachably connected to the upper part of the transmission case 1.
The mission case 1 portion includes an input shaft 2 to which power is transmitted from the installed engine (not shown), a first gear shift shaft 3, a second gear shift shaft 4, and a rear wheel of the tractor (not shown). Output shafts 6 and the like that are interlocked with the differential gear 5 are supported with their axes parallel to each other, and the auxiliary transmission case 7 includes a third gear shifting shaft 8 and a fourth gear shifting shaft. A shaft 9 and a fifth shaft 10 for speed change are supported.

A main transmission system is configured through a group of gears supported by the first shaft 3, the second shaft 4, and the output shaft 6, and
An auxiliary transmission system is constructed through a gear group in which the third shaft 8, fourth shaft 9, and fifth shaft 10 are pivotally supported.

First, to explain the main transmission system, the input shaft 2
and the first shaft 3 are interlocked with each other by gears, and a transmission gear group 3a, 3b is fixed to the first shaft 3.

3C, three main transmission shift gears 4a, 4b, and 4C spline-connected to the second shaft 4 are selectively engaged with each other to perform three forward gears, and the second shaft By selectively engaging the two main transmission shift gears 6a and 6b spline-connected to the output shaft 6 with the gear groups 14e and 14f fixed to the gear shift gears 14e and 14f, the three-speed shift state is changed to a high-speed shift range. It is configured to shift into two large speeds in the low speed range.

Although not illustrated, the main transmission shift gear 4a...
- By engaging the first gear 4a of the
A backward state is created in which the vehicle is reversed.

Next, to explain the auxiliary transmission system, an input gear 8a fixed to the third shaft 8 is rotatably supported by the second shaft 4 and connected to a gear 3a fixed to the first shaft 3. The output that is engaged with the engaged transmission gear 4d and transmitted to this input gear 8a is decelerated and interlocked by a two-stage gear 9a that is relatively rotatably supported from this input shaft 8a to a fourth shaft 9. The gear 9a is further decelerated by a second gear 10a which is rotatably supported by the fifth shaft 10, and the second gear 10a is spline-connected to the fourth shaft 9. The gear 9 is further decelerated by a certain sliding gear 9b, and is fixed to the fourth shaft 9.
C is further decelerated by a gear 10b fixed to the fifth shaft 10, and the output that is linked to the deceleration by the fifth shaft 10 is transferred to the second shaft connected to the fifth shaft 10 by a spline.
Using two shift gears 10C and 10d, the gears 9d and 9e are rotatably supported on the fourth shaft 9, and the gears 9d and 9e are further interlocked for deceleration.
The gear 4b of the second shaft 4, which is relatively rotatably supported on the shaft 8, and the output gear 8b, which are in constant engagement, are configured to further reduce the speed.

Therefore, this auxiliary transmission system transmits the output transmitted to the input gear 8a to the main transmission shift gear 4b from the output gear 8b after extremely decelerating, and the second transmission gear 4b of the main transmission transmission system Only when the gear 3b of the first shaft 3 is out of mesh with the gear 3b of the first shaft 3, the sliding gear 9b enters a transmission operating state in which it is engaged with the second gear 10a and drives the rear wheels. When the second transmission gear 4b of the transmission system is not in mesh with the gear 3b of the first shaft 3 and the rear wheels are driven by the output of this main transmission system, the sliding gear 9b and the second gear 10a The occlusion is cut off, and the occlusion is maintained in a neutral free rotation state.

Further, the output gear 8b is configured to have a wide width so that it can always mesh with the main transmission gear 4b even when the main transmission gear 4b is shifted.

In the embodiment, the auxiliary transmission system is an ultra-reduction system, but it can be implemented in various forms, such as being used as an ultra-high-speed system, for example.

Further, in the embodiment, the auxiliary transmission system itself is capable of freely changing the speed change state to two stages, but it may be configured to be able to freely change the speed change state to three or more stages, or it may not change the speed change state. It may be implemented in the form of

Furthermore, in carrying out the present invention, the main transmission shift gear that engages with the output gear 8b of the auxiliary transmission system may be any shift gear, if a plurality of main transmission gears are installed in the main transmission system. Of course it's a good thing.

[Brief explanation of drawings]

The drawing is a longitudinal sectional side view illustrating an embodiment of the traveling transmission structure for an agricultural tractor according to the present invention. 2... Input shaft, 3... First shaft for speed change, 3a, 3b. 3C... Gear for shifting, 4... Second shaft for shifting, 4a,
4b, 4C... Main transmission shift gear, 4d... Transmission gear, 9b... Clutch, 8b... Output gear.

Claims (1)

[Scope of utility model registration request] A first shift shaft 3 that is gear-interlocked with the human power shaft 2, and shift gears 4a, 4b, 4 that can be selectively interlocked with gears 3a, 3b, and 3C fixed to the first shift shaft 3.
a second shaft 4 for main transmission having a group C; and an auxiliary transmission system that is loosely fitted onto the second shaft 4 for main transmission and constantly engaged with one of the gear groups 3a of the first shaft 3 for transmission. a transmission gear 4d to the auxiliary transmission system, and an output gear of the auxiliary transmission system in which the power from the interlocking gear 4d is always engaged with one 4b of the gear group of the second shaft 4 for main transmission. 8b is provided with a latch 9b that can be switched between a transmission state and a non-transmission state, and one of the shift gears of the second main transmission shaft 4 is engaged with the gear of the first transmission shaft 3. Then, the power from the input shaft 2 is transmitted to the running wheels via the main transmission system, and the clutch 9b of the auxiliary transmission system is engaged and operated,
In the traveling transmission structure of an agricultural tractor capable of switching the state in which the power from the human power shaft 2 is transmitted to the traveling wheels via the auxiliary transmission system, the shift gear 4b meshed with the output gear 8b of the auxiliary transmission system is connected to the transmission gear 4b. Even in the state in which the shift gear 4b is engaged with the gear 3b of the first shaft 3, both gears 4b are engaged with the output gear 8b of the auxiliary transmission system.
, 8b.