JPH0444431Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention combines a double clutch connected to the output shaft from the engine, and a gear type transmission equipped with a traveling system and a PTO system transmission mechanism. The present invention relates to a power transmission device for an agricultural tractor in which a shaped outer shaft and an inner shaft inserted therein are interlocked and connected.

[Conventional technology]

As the above-mentioned power transmission device, for example,
There is one disclosed in Publication No. 12142.

The inner shaft, which is interlocked with the double clutch, is a traveling system, and the outer shaft is a PTO system, and when the first stage of the double clutch is operated, the transmission to the inner shaft is cut off, and the second stage It is constructed so that the power transmission to the PTO system can be cut off by operation, and when changing the traveling gear while driving, the double clutch can be operated to the first gear to shift only the traveling system while driving the PTO system. It is now possible to perform gear shifting operations by cutting off the transmission.

In the above-described power transmission device, since the inner and outer shafts are long, a bearing bush is often interposed between the two shafts in order to maintain them concentrically. However, when a bushing is interposed between the inner and outer shafts in this way, when the power transmission from only the inner shaft is cut off to change the traveling speed, the rotational force of the outer shaft (PTO system), which continues to drive, is transferred to the inner shaft via the bushing. The rotational speed of the traveling system may not be sufficiently reduced due to so-called entrainment, which may make it difficult to smoothly perform a gear shift operation in the traveling system.

Therefore, in the above-mentioned conventional example, when a blade wheel that rotates in lubricating oil stored in the transmission case is incorporated into the gear type transmission of the traveling system, and the transmission of only the traveling system is cut off as described above, A means is employed to quickly reduce the rotation of the traveling system by using oil agitation resistance acting on the impeller.

[Problem that the invention attempts to solve]

However, the above-mentioned method that utilizes the stirring resistance of lubricating oil requires a relatively large impeller to obtain the desired resistance, and can only be applied to models with sufficient free space in the transmission case. It was hot.

The present invention has been developed in view of the above-mentioned circumstances, and an object of the present invention is to provide a desired rotational resistance with a compact configuration.

[Means for solving problems]

The characteristic configuration of the present invention, which was made to achieve the above object, is that there is a gap between a back shaft assembled and fixed in a gear type transmission and a boss portion of a bag gear rotatably fitted on the back shaft. The reason is that an oil seal is inserted to provide friction, and its effect and
The effects are as follows.

[Effect]

In other words, rotational resistance is imparted to the back gear by interposing an oil seal between the boss of the back gear, which is constantly interlocked with the inner shaft, and the back shaft assembled and fixed in the gear type transmission. Thus, when the first stage operation of the double clutch is performed and power transmission to the traveling system is cut off, the rotation of the shaft of the traveling system can be quickly reduced.

[Effect of idea]

Therefore, according to the present invention, even if the model does not have enough free space in the transmission case to house a relatively large impeller, the existing equipment of the back gear and back shaft can be used. When the drive system power is cut off, it is possible to provide enough rotational resistance to prevent the PTO system from rotating along with the drive system and quickly reduce the rotation of the drive system.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

As shown in FIG. 4, an engine E is disposed within the front hood 1 of the aircraft, a clutch housing 2 integrally connected to the rear end of the engine E, a fuel tank 3, a radiator 4, and a cooling fan 5 are supported by a frame 6. In addition, a transmission case M is provided at the rear of the fuselage, which houses a gear type transmission F that receives power transmitted from the output shaft of the clutch housing 2, and the drive unit 7 is installed in the middle of the fuselage. A lift arm 10 that can be supported by 8 and 9 and run and that can drive a working device such as a tilling device up and down at the rear end of the body, and transmits power to the working device.
An agricultural tractor equipped with a PTO shaft 11 is configured.

A double clutch type power transmission device to which the present invention is applied is shown in FIG.

The clutch housing 2 is equipped with a double clutch 12 having a first clutch A for cutting off the power of the traveling system and a second clutch B for cutting off the power of the PTO system.
When the clutch pedal 13 is depressed to the first step, only the first clutch A of the travel system is disconnected, and when the clutch pedal is further depressed to the second step, the vehicle starts traveling. The first clutch A of the system and the second clutch B of the PTO system are disengaged.

Specifically, the first clutch A includes a flywheel 16 that rotates integrally with the output shaft 14 of the engine E, an inner shaft 15 whose one end is rotatably supported by the flywheel 16, and a spline on the inner shaft 15. The fitted first disk 18a and the first disk 18
The first part that clamps a in cooperation with the flywheel 16
The second clutch B is composed of a pressure plate 19a and the like, and the second clutch B is connected to the second flywheel 1 fixed to the flywheel 16.
6b, an outer shaft 21 externally fitted and supported on the inner shaft 15 via a bush 20, a second disk 18b spline-fitted to the outer shaft 21, and a second disk 18.
It is composed of a second pressure plate 19b, etc., which clamps the flywheel 16b in cooperation with the second flywheel 16b. Then, at a plurality of locations in the circumferential direction of the first pressure plate 19a, the first pressure plate 19a and following it, the second pressure plate 19 are moved backward toward the mission case M side, and the first pressure plate 19a is moved backward toward the mission case M side. Disk 18a and second disk 1
a release mechanism 2 for sequentially releasing the clamping state of the clutch 8b and disconnecting the first clutch A and the second clutch B;
2, and a clutch release hub 23 for operating the release mechanism 22 is fitted onto the outer shaft 21 so as to be slidable in the axial direction.
The release mechanism 22 is configured to release the clutch by sliding the clutch release hub 23 toward the engine E side.

The release hub 23 is adapted to slide in conjunction with the rocking of a clutch release fork 24 linked to the clutch pedal 13.

Next, the gear transmission F will be explained based on FIG. 3.

The inner shaft 15 is operatively connected to a first shaft 26 via a ball coupling 25, and three drive gears 41, 42, 43 are fitted to the first shaft 26.

Two shift gears 44 and 45 are spline-fitted to the second shaft 27, and the third drive gear 4
3, a first free rotation gear 48 that is always engaged with the first rotating gear 48 is externally fitted,
By shifting the first shift gear 44 to the left in the figure, it engages with the first gear portion 51a of the back gear 51 shown in FIG. By shifting the second shift gear 45 to the left, it engages with the second drive gear 42 to become the second forward speed, and by shifting to the right, the second forward speed becomes the first speed.
It is configured to mesh with the free rotating gear 48 to achieve three forward speeds. Note that the second gear of the back gear 51
The gear portion 51b is always engaged with the second drive gear 42.

A third shaft 28 is interlocked and connected to the second shaft 27, and second and third free rotating gears 49, 50 are connected to the third shaft 28.
By loosely fitting the sleeve 38 to the third shaft 28 and spline-fitting the sleeve 38 to the third shaft 28, and shifting the sleeve 38 to the left, the third shaft 28 and the second free rotating gear 4 are connected.
The first sub-transmission mechanism C is configured such that the gears 9 rotate together, and the third shaft 28 and the third idle gear 50 rotate together by shifting to the right.

Four intermediate gears 53, 54, 5 on the fourth shaft 29
5 and 56, of which the first intermediate gear 53
are always engaged with the second free rotation gear 49, and the fourth intermediate gear 56 is always engaged with the third free rotation gear 50, respectively.
Then, by shifting the third shift gear 46 spline-fitted to the output shaft 33 to the traveling system to the left, it becomes the second intermediate gear 54, and by shifting it to the right, it becomes the third intermediate gear 55. A second auxiliary transmission mechanism D that can be engaged with each other is constructed, and in synergy with the first auxiliary transmission mechanism C, a total of four stages of auxiliary transmission can be performed.

An outer shaft driving gear 59 is provided at the end of the outer shaft 21 on the mission case M side, and is always engaged with the first driven gear 58 fitted to the fifth shaft 30. Furthermore, a fourth shift gear 4 is attached to the fifth shaft 30.
7 is spline-fitted, and the fourth idler gear 6
0, and by shifting the fourth shift gear 47 to the left, it engages with the fifth intermediate gear 57 fitted to the sixth shaft 31, and by shifting it to the right, the sixth intermediate gear It is arranged to engage with the fourth free rotating gear 60 which is always engaged with the gear 58.
In other words, by selectively shifting the fourth shift gear 47 to the left or right, the sixth shaft 3
First, the power from the PTO system can be transmitted in two stages.

Two transmission shafts 34a are provided behind the sixth shaft 31,
34b, the front transmission shaft 34a is gear-linked with the mid-PTO shaft 35 protruding forward at the bottom of the transmission case M, and the rear transmission shaft 34b is connected to the transmission case M via the reduction mechanism E. The gear is interlocked with the PTO shaft 11 protruding from the rear end, and the power from the outer shaft 21 is transferred to the PTO shaft 11.
It is made so that it can be taken out.

In the above configuration, in the present invention, the following structure is added in order to quickly reduce the rotation of the inner shaft 15 of the traveling system when only the first clutch A of the traveling system is disengaged. .

That is, as shown in FIG. 1, a cylindrical portion 52a having a larger diameter than the back shaft 32 is integrally molded on the right end surface of the boss portion 36 of the back gear 51, and a ring is formed between the cylindrical portion 52 and the back shaft 32. The oil seal 37 is press-fitted, and then the oil seal 3
7, the fixed back shaft 32, and the back gear 51, frictional rotational resistance is applied to the inner shaft 15 interlocked with the back gear 51. Note that holes 39 are provided at several locations in the circumferential direction of the cylindrical portion 52a, and the oil in the mission case M is distributed through the holes 39 to the relative rotation portion between the boss portion 36 and the back shaft 32. .

As described above, in the present invention, by imparting rotational resistance to the back gear 51, the first
Even when only the clutch A is disengaged and the first and second shift gears 44 and 45 are in the neutral position, the power transmitted from the outer shaft 21 through the bush 20 is suppressed to reduce the rotation speed of the inner shaft 15. It can be lowered. Furthermore, since the back gear 51 rotates at a relatively high speed, it has the advantage that even if the oil seal 37 is press-fitted with a small force, an effective rotational load can be generated.

In carrying out the present invention, a larger rotational load can be applied to the inner shaft 15 by installing a plurality of oil seals 37 as shown in FIG.

Further, although numbers are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an embodiment of the power transmission device for an agricultural tractor according to the present invention, in which FIG. 1 is a vertical side view of the back shaft portion, FIG. 2 is a vertical side view of the double clutch portion,
Figure 3 is a longitudinal cross-sectional side view of the gear type transmission section, Figure 4
The figure is an overall side view of an agricultural tractor. FIG. 5 is a longitudinal sectional side view of a main part of another embodiment. 12...Double clutch, 14...Output shaft, 1
5...Inner shaft, 21...Outer shaft, 32...Back shaft,
36...Boss part, 37...Oil seal, 52...
...back gear, E...engine, F...gear type transmission.

Claims (1)

[Scope of utility model registration request] A double clutch 12 connected to an output shaft 14 from an engine E, and a gear type transmission F equipped with a traveling system and a PTO system transmission mechanism are connected to a cylindrical outer shaft 21 and an inner shaft 15 inserted therein. In the power transmission device for an agricultural tractor, which is interlocked and connected, the back shaft 32 is assembled and fixed in the gear type transmission F, and the boss portion 36 of the bag gear 52 is rotatably fitted onto the back shaft 32. A power transmission device for an agricultural tractor in which an oil seal 37 is interposed between the two for providing friction.