JPH0143182B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a transmission mechanism for a tractor.

<Conventional technology> As schematically shown in Figure 6, conventional small tractors used in Japan have a transmission shaft system that changes speed for traveling, and a rotational power output to the traction machine (hereinafter referred to as The transmission shaft system that changes the speed of the PTO (abbreviated as PTO) is shared in order to simplify the mechanism, and the rotational power from the engine is transferred at once by a single clutch attached to the flywheel. At the same time, intermittent
It is customary to change gears for driving and PTO.

In this case, even when changing speed or intermittent operation of either of the two systems mentioned above, the two systems will be used in conjunction with each other, which is why rotary tillers, which are often used for paddy cultivation, etc. Although it can be said to be an extremely rational mechanism, in recent years more and more tractors have been shipped overseas, and the types and types of work that can be done with these tractors have expanded, such as mowers, snow blowers, trenchers, forage harvesters, etc. In addition, there are an increasing number of applications in which it is necessary to separately and independently perform gear shifting and intermittent switching in the two systems. To meet such demands, a mechanism in which a double clutch is mounted on the flywheel of the engine, as schematically shown in FIG. 7, is generally used.

<Problems to be Solved by the Invention> However, the above-mentioned mechanism cannot be used for heavy traveling work, such as a front loader, in which only the clutch of the traveling system is frequently used and rotational power is repeatedly interrupted. In this case, the dissipation of frictional heat and the slippage during the so-called half-clutch are insufficient compared to single clutch specifications, resulting in frequent accidents where the clutch burns out and transmission becomes impossible. Also, when changing from single clutch specification to double clutch specification,
This requires an extremely large number of man-hours, leading to problems such as decreased productivity and increased costs.

<Means for Solving the Problems> The present invention solves these problems and uses a single clutch to easily and independently transmit power to the two systems, the traveling system and the PTO system. An input main shaft to which the rotational power of the engine is intermittently transmitted, and a travel gear and PTO that mesh and rotate with the gears on the main shaft.
In a tractor transmission mechanism, the main shaft and two countershafts for speed change are mounted in a parallel horizontal state. It is formed into an overall hollow shaft that can form a heavy shaft, and a gear that engages and rotates with the gears on both countershafts is integrally engraved on the rear end, and both countershafts are connected below the main shaft. By distributing and arranging the left and right countershafts in the positions, a spare accommodation chamber for the clutch to be additionally installed on the solid shaft of the main shaft is defined between the two countershafts. In addition, the main shaft consists of a hollow shaft to which rotational power is intermittent by a single clutch, and a solid shaft that passes through the hollow interior and is rotated independently of the hollow shaft by the engine. It is formed into a double shaft, and a traveling speed change counter is installed at the rear end of the hollow shaft.
By integrally carving a gear that engages and rotates with a gear on the shaft, and arranging both countershafts in left and right pairs below the main shaft, both countershafts A spare accommodation chamber for the clutch is defined between the clutches, a multi-disc clutch is installed on the solid shaft of the main shaft facing into the accommodation chamber, and the hub gear of the multi-disc clutch is connected to the gear on the PTO transmission countershaft. The second feature is that it meshes with the

<Example> Hereinafter, the specific structure of the present invention will be described in detail based on the illustrated example. First, FIGS. 11 is the engine mounted on the front of the tractor body T, 11 is its crankshaft, and the flywheel 1 rotates integrally with this crankshaft.
2 faces into the clutch housing S1, and a spline hub 13 is fixed to the center of the flywheel 12 by bolts 14.

The rear part of the crank housing S1 is divided into a gear chamber 15 that also serves as an oil tank for heat dissipation, and the rear part is further divided into a transmission case S2 and a final transmission case S.
3 are sequentially connected and integrated. Both cases S
2. Of course, S3 also serves as a heat radiation oil tank. The following three shafts are enclosed in a special arrangement within the crack housing S1 and transmission case S2.

That is, in the enlarged expanded plan view of FIG. 4 which extracts this, M is a horizontal input main shaft installed on the same axis as the crankshaft 11, the front part of which is connected to the spline hub 13, and the rear part of which is connected to the spline hub 13. Both are supported by bearings 17 and 18 on a partition wall 16 from the gear chamber 15. C1 is a general term for a single clutch, and its clutch cover 19 is fixed to the flywheel 12. 2
Similarly, 0 is a clutch disk, which is spline-fitted to the main shaft M. 21 is a pressure plate, 22 is a clutch release hub, and its thrust bearing 23 presses the release lever. 25 indicates a release fork that hangs down from the clutch lever 26.

Engine 10 by the above single clutch C1
Main shaft M to which rotational power is intermittent from
consists of a hollow shaft 27 as a whole, and a gear 28 is integrally carved in the rear end facing into the gear chamber 15. In addition, F and P are for traveling transmission and PTO.
This is a general term for the gear shift countershaft, and these are in a horizontal state parallel to the main shaft M, and the gear chamber 15 and transmission case S are
2, etc., and are arranged in such a way that all of them are located below the rotational axis of the crankshaft 11, and are divided into left and right.

In other words, as is clear from Fig. 2, both countershafts F and P are aligned on the left and right sides in the lower stage so that the main shaft M is located at the remaining two vertices Y and Z of the virtual triangle, which is the top vertex X. The countershafts F and P are arranged in parallel to form a gear chamber 15.
At the location facing inward, a preliminary accommodation chamber R is secured for additionally installing a clutch, which will be described later based on FIG.

Furthermore, a partition wall 29 that forms a boundary between the gear chamber 15 of the clutch housing S1 and the transmission case S2 has a bearing case fitting that faces the rear end of the hollow shaft 27 on the same axis as the main shaft M. The abutment 30 is also formed with an opening, and as is clear from FIG.
It is planned to be able to stably support the rear end portion of the solid shaft that passes through the hollow interior of the hollow shaft 27.

The front part of the traveling speed change countershaft F is defined as a front hollow shaft 31,
It is constructed within the gear chamber 15 of the clutch housing S1, and its front and rear ends meet the above-mentioned walls 16, 2.
9, and meshes with the gear 28 on the main shaft M via a gear 34 spline-fitted to the front end thereof. 35 is a collar for positioning the mesh. Similarly, the rear part of the countershaft F extends into the transmission case S2 as a rear solid shaft 36, and is spline-fitted at its front end to rotate integrally with the front hollow shaft 31.

On the way that the rear solid shaft 36 faces into the main transmission chamber 37 of the transmission case S2, there are a plurality of gears 38 forming a traveling transmission gear group.
39, 40, and 41 are fitted together so as to be rotatable as one unit, and a pair of front and rear hub gears 43, 44 for forward/reverse switching are loosely located on the way where the rear solid shaft 36 faces into the sub-transmission chamber 42. They are fitted in such a way that they rotate. 45 is a coupling sleeve for switching between forward and reverse movement.

On the other hand, the front part of the PTO transmission countershaft P is also set as a front hollow shaft 46, preferably in the same form as the front hollow shaft 31 of the traveling transmission countershaft F, and both front and rear ends thereof are also provided with bearings 47, It is supported by 48. A gear 49 is spline-fitted to the front end of the front hollow shaft 46, and rotates while meshing with the gear 28 on the main shaft M. 50 indicates a collar for positioning the mesh.

Similarly, the rear part of the countershaft P is extended as a rear hollow shaft (PTO shaft) 51 to the rear of the tractor body T while passing through the transmission case S2. It is supported in a rotatable envelope. A plurality of gears 53, 54, 55, and 56 are spline-fitted to the hollow countershaft 52, and constitute a PTO gear group, with a pair of front and rear coupling sleeves 57, 58 interposed therebetween. has been done.

It goes without saying that the coupling sleeves 57 and 58, like the coupling sleeve 45 described above, are spline-fitted to be slidable in the axial direction while rotating integrally with the shaft to which they are fitted.

Further, at the location where the hollow countershaft 52 faces the sub-transmission chamber 42 of the transmission case S2, both forward and reverse gears 59, 6 are provided.
0 is fixedly installed, and corresponds to the hub gears 43 and 44 on the traveling speed change countershaft F. Reference numeral 61 designates a reverse idle gear shaft installed in parallel within the auxiliary transmission chamber 42 at a lower position facing the mutual middle of the traveling and PTO transmission countershafts F and P. As shown in FIG. 3, the hub gear 44 on the traveling transmission countershaft F and the gear 60 on the PTO transmission countershaft P are meshed and connected through the hub gear 44 on the travel transmission countershaft F.

According to the configuration of the basic embodiment described above, the fourth
As is clear from the figure, while the single clutch C1 attached to the flywheel 12 of the engine 10 is shared, the traveling transmission system and the PTO transmission system are connected to each other.
It is possible to connect and disconnect the system all at once, and also to change the speed in a predetermined manner, which is effective mainly for use in rotary tilling work.

Furthermore, FIG. 5 shows a modified embodiment of the present invention corresponding to FIG. 4, in which the basic embodiment described above is used as a so-called standard specification mechanism, and the following slight configuration is added to the mechanism. This allows the two systems described above to be used for transmission operations separately and independently.

That is, in the above basic embodiment, due to its structure, the main shaft M is formed as a hollow shaft 27 as a whole, and the rear end of the hollow shaft 27 facing into the gear chamber 15 has a drive gear and a PTO shaft. Since a spare accommodation chamber R for the clutch is also secured between the left and right sides of both the gear shift countershafts F and P, the hollow shaft 27 and the solid shaft 63 that is rotated separately from the hollow shaft 27 can be inserted into the hollow shaft. The main shaft M is formed into a double shaft by passing through the hollow interior of 27, and the main shaft M is formed into a double shaft from both shafts 27 and 63, and at a position where the solid shaft 63 faces into the preliminary storage chamber R, there is a countershaft P for PTO transmission. A multi-disc clutch C2 for intermittent rotational power is installed, and the hub gear 64 of the clutch C2 is connected to the PTO shifting countershaft P.
By meshing with the upper gear 49, it is possible to obtain a modified specification that is optimal for heavy traveling work such as a front loader, for example.

To explain this based on FIG. 5, the front end of the solid shaft 63 in the main shaft M is spline-fitted to rotate integrally with the spline hub 13 of the flywheel 12, and the clutch housing S1 The rear end portion of the gear chamber 15 that extends vertically through the gear chamber 15 is rotatably supported by a bearing 67 of a bearing case 66 that is fitted and fixed into the fitting opening 30 of the partition wall 29 with bolts 65. In the middle of the solid shaft 63 facing into the preliminary accommodation chamber R, a multi-plate clutch C2 is assembled and constructed.

Reference numeral 68 denotes the clutch disk, which is spline-fitted to the solid shaft 63 of the main shaft M. 69 is also a pressure plate,
70 is a clutch cover. The clutch hub gear 64 is fitted onto the solid shaft 63 via a bearing 71 so as to freely rotate. Moreover, the hub gear 64 meshes with a gear 49 spline-fitted to the front hollow shaft 46 of the PTO transmission countershaft P.

In other words, as is clear from Figure 5, the PTO
The gear 49 on the speed change countershaft P is the same as the gear 28 on the hollow shaft 27 of the main shaft M.
is not engaged. Additionally, a collar 50 is used to position the gear 49 in mesh with the clutch hub gear 64.
However, as shown in Fig. 5, it is divided into two parts, front and back.

Therefore, according to the configuration of this modified embodiment, not only can the rotational power of the traveling system be interrupted by the single clutch C1 which remains attached to the flywheel 12 of the engine 10, but also it can be Solid shaft 6 in main shaft M
Snow blowers, mowers, and loaders in which the rotational power of the PTO system can be intermittent using the multi-disc clutch C2 shown in 3 above, and as a result, it is necessary to stop traveling while only rotating the PTO shaft 51. Ideal for various tasks such as still,
Other configurations in the above modified embodiment include the first to
Since it is substantially the same as the basic embodiment shown in FIG. 4, the detailed explanation thereof will be omitted except that the same reference numerals as those in FIGS. 1 to 4 are written in FIG.

<Effects of the Invention> As described above, in the present invention, the single clutch C
1, to which the rotational power of the engine 10 is intermittently transmitted, and two countershafts F, P for travel transmission and PTO transmission that mesh and rotate with the gear 28 on the main shaft M. In a tractor transmission mechanism in which the shafts are mounted in a parallel horizontal state, in particular, the main shaft M has a double shaft in combination with a solid shaft 63 that is rotated separately and independently by the engine 10. The rear end of the hollow shaft 27 is integrally carved with a gear 28 that engages and rotates with the gears 34 and 49 on both countershafts F and P. By distributing and arranging the countershafts F and P in parallel to form left and right pairs at the lower position of the main shaft M, the countershafts F and P are placed on the solid shaft 63 of the main shaft M between the two countershafts F and P. Since a spare accommodation chamber R is defined for an additional clutch to be installed, the single clutch C1 can be used as it is for both the travel system and the PTO system, and can perform intermittent rotational power and speed changes. This makes it possible to obtain the optimum specifications for rotary tillage work.

Further, the main shaft M is connected to a hollow shaft 27 to which rotational power is intermittent by the single clutch C1.
and a solid shaft 63 that passes through the hollow interior and is rotated independently of the hollow shaft 27 by the engine 10, and is formed into a double shaft, which is secured in advance as described above. By additionally installing a multi-plate clutch C2 on the solid shaft 63 of the main shaft M facing into R, and meshing the hub gear 64 of the multi-plate clutch C2 with the gear 49 on the PTO shifting countershaft P, the above-mentioned The two systems can be used for power transmission separately and independently, and specifications suitable for various operations such as loaders and snow blowers can be obtained. Furthermore, the specifications can be changed extremely easily by simply adding the solid shaft 63, the multi-disc clutch C2, etc., and this is effective in selective production in accordance with market demands and cost reduction.

Furthermore, even when the above two systems are used for transmission independently, the rotational power of the drive system is intermittent by the single clutch C1, so the tractor can be moved very smoothly by operating the so-called half-clutch. In addition to being able to start the vehicle, the heat dissipation effect is also achieved efficiently, and there is no risk of causing a burnout accident. On the other hand, since the PTO system is disconnected and disconnected by the multi-plate clutch C2, the intermittent action of the rotational power is reliably achieved, and heavy work can be carried out with peace of mind.
It is very profitable.

[Brief explanation of drawings]

FIG. 1 is an overall schematic side view of the tractor according to the present invention, and FIGS. 2 and 3 are the - lines and - of FIG. 1.
4 is a partially enlarged sectional view taken along the line; FIG. 4 is an exploded sectional plan view extracting the transmission mechanism; FIG. 5 is an expanded sectional plan view of a modified embodiment corresponding to FIG. 4; The figure is a side sectional view schematically showing two types of conventional mechanisms. T...Tractor body, S1...Clutch housing, S2...Transmission case, M
...Input main shaft, C1, C2...Clutch, F...Countershaft for traveling speed change, P...
... Countershaft for PTO transmission, R... Reserve storage chamber for clutch, 10... Engine, 12...
Fly hole, 15... Gear room, 27, 31, 4
6...Hollow shaft, 28, 34, 49...Gear, 3
6, 51, 63...Solid shaft.

Claims (1)

[Scope of Claims] 1. An input main shaft M to which the rotational power of the engine 10 is intermittently transmitted by a single clutch C1, and an input main shaft M for traveling transmission and a PTO transmission that meshes and rotates with a gear 28 on the main shaft M. In a transmission mechanism in which both countershafts F and P are mounted in a parallel horizontal state, the main shaft M is coupled with a solid shaft 63 that is rotated separately and independently by an engine 10. The shaft is formed into an overall hollow shaft 27 that can form a double shaft, and a gear 28 that engages and rotates with the gears 34 and 49 on both countershafts F and P is integrally engraved on the rear end thereof. By distributing and arranging the countershafts F and P in a left and right pair at a position below the main shaft M, the countershafts F and P are placed on the solid shaft 63 of the main shaft M between the two countershafts F and P. A tractor transmission mechanism, characterized in that a spare accommodation chamber R is defined for another clutch that is additionally installed in the tractor. 2 The front ends of both countershafts F and P are defined as front hollow shafts 31 and 46, and the gear 28 on the main shaft M is attached to the hollow shafts 31 and 46.
The claims are characterized in that the gears 34 and 49 that are meshed and rotated are spline fitted to each other.
The transmission mechanism of the tractor according to item 1. 3. An input main shaft M to which the rotational power of the engine 10 is intermittently transmitted by a single clutch C1, and both countershafts F, P for traveling transmission and PTO transmission that mesh and rotate with the gear 28 on the main shaft M. In this transmission mechanism, the main shaft M is connected to a hollow shaft 27 to which rotational power is intermittent by the single clutch C1, and
A solid shaft 63 that passes through the hollow interior and is rotated independently of the hollow shaft 27 by the engine 10.
A gear 28 is integrally carved into the rear end of the hollow shaft 27 to mesh and rotate with the gear 34 on the traveling transmission countershaft F, and both countershafts F and P are formed into a double shaft. By distributing and arranging them in pairs on the left and right at a position below the main shaft M, a spare storage chamber R for a separate clutch is defined between the countershafts F and P, and the storage chamber The feature is that a multi-disc clutch C2 is installed on the solid shaft 63 of the main shaft M facing into R, and the hub gear 64 of the multi-disc clutch C2 is meshed with the gear 49 on the PTO shifting countershaft P. Tractor transmission mechanism.