JPS61116154A - Transmission in self-propelling working vehicle - Google Patents

Abstract

PURPOSE:To aim at miniaturizing a transmission, by rotating a backward gear loosely fitted onto a second transmission shaft in the direction opposite to the direction of rotation of a series of speed change gears on a second transmission shaft, by means of a first transmission shaft through a small gear fixed onto the first transmission shaft and a large gear on a support shaft. CONSTITUTION:A backward gear 41 on a second transmission shaft 25 is rotated at a relatively low speed by means of a first transmission shaft 24 through a gear speed change mechanism composed of a small gear 48 on the first transmission gear 24 and a large gear 45 on a support shaft 42. The rotational direction of the backward gear 41 is reverse to the rotational direction of a series of speed change gears 35 through 39 on the second transmission shaft 25. Further, the rotation of a lowest speed shift stage gear 34 on the first transmission shaft 24 is decreased by two stages through a gear speed reduction mechanism composed of gears 48, 45 and a gear speed reduction mechanism composed of a small gear 46 of the support shaft 42 and a small diameter gear 34.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a new transmission suitably used in a relatively small self-propelled work RL such as a mower tractor.

More specifically, this invention provides a transmission shaft which is provided parallel to the transmission case 1 between the first transmission shaft and the second transmission shaft, rotates on the first transmission shaft with the second transmission shaft, In order to be driven, a plurality of transmission gear trains are disposed loosely fitted on the second transmission shaft and a plurality of gears are meshed with each other. Protruding in the radial direction from inside the transmission shaft, one of the gears on the second transmission shaft is selectively attached to the second transmission shaft, and the first transmission shaft is connected to the second transmission shaft, and the first transmission shaft is connected to the second transmission shaft. This invention relates to an improved transmission of the type in which the shaft is interlocked with the left and right final travel drive means, respectively.

Conventional technology The above-mentioned type of transmissive system is disclosed in US Pat. No. 8, for example.
, 812, 785 and No. 4,105, 566: It is already well known that a plurality of gears loosely fitted on the second transmission shaft are selectively connected to the second transmission shaft. The means for coupling to the shaft to obtain a gear shift includes a clutch portion protruding from within the second transmission shaft, rather than a shiftable clutch means such as that provided on the second transmission shaft. The shiftable gear shifting means in the second transmission shaft enables a series of gears to be closely arranged on the second transmission shaft with substantially no gaps between them, and thus A series of multiple gears on the first transmission shaft where the multiple gears are constantly meshed are similarly closely arranged to create an extremely compact transmission tonal.

In order to interlock and connect the aforementioned second transmission shaft to the left and right final travel drive means, which are single-wheel crawlers, the left and right output shafts C extending left and right from the mission case circle are 1.
If there is no complete differential system installed that provides a difference in rotational speed between the left and right final travel drive means when the vehicle turns, the method disclosed in the aforementioned U.S. Patent No. 8,812,735 may be used. When the second transmission shaft is extended from the transmission case to the left and right and is used as the output shaft as it is, the above-mentioned differential device is provided.
Q.3,566, the first and second
Left and right output shafts concentrically arranged parallel to the transmission shaft are separately provided, and the differential device is disposed between the left and right output shafts using the left and right output shafts as output means. US patent m4,108
In the transmission disclosed in , 566, the second transmission shaft and the first transmission shaft are located closer to the differential gear,
The differential is operatively connected to the second transmission shaft via a reduction gear mechanism including an idler gear loosely fitted on the first transmission shaft, and a series of transmission gears on the first transmission shaft are connected to the second transmission shaft. It is disposed outside the differential gear when viewed in the axial direction of the differential gear so as not to interfere with the differential gear or its differential case.

When using a mobile work vehicle, it is often necessary to reverse the vehicle at a relatively low speed. Therefore, one problem with this type of transmission is how to incorporate the reverse mechanism without sacrificing compactness. Both of the above-mentioned U.S. patents have a series of speed change gears made up of a plurality of gears on both transmission shafts meshing with each other, and during operation, the second transmission shaft is moved in the opposite direction from the first transmission shaft. In contrast, a chain transmission mechanism is provided in which a chain is wound around a sprocket fixedly installed on the first transmission shaft between the two transmission shafts and a second sprocket loosely fitted on the second transmission shaft. 2. Use the sprocket on the transmission shaft as a clutch! :The eL can be selectively coupled to the transmission shaft, and can be rotated in the same direction as the second transmission shaft and the first transmission shaft, thereby enabling the eL to move backward. However, in this structure, in addition to the above-mentioned speed change shifting means that selectively connects the series of speed change teeth t on the i2 transmission shaft to the second transmission shaft, the above-mentioned clutch for connecting the sprocket is not required. do.

Also, depending on the type of work being performed using the 70-metre vehicle, the traveling vehicle is required to run at extremely low vehicle speeds during work that places a high load on the vehicle. However, it is desirable that the vehicle be able to maintain a high vehicle speed if the vehicle is lined up in line, as stipulated by the regulations for driving on the road.

In a structure in which the second transmission shaft is interlocked and connected to the differential gear via a reduction gear mechanism, as in the above-mentioned U.S. Patent No.
Rotation of the transmission shaft! ! Since i and speed n can only be applied to the left and right output shafts, the above two requirements fc cannot be satisfied at the same time. However, when the distance between the first transmission shaft and the second transmission shaft is widened and a multi-speed gear train with a wide range of speeds is provided, which provides a range of speeds from high speed to very low speed. In this case, the compactness of the ERI transmission is sacrificed to increase the distance between the shafts.

Problem to be Invented Therefore, the main purpose of this invention is to connect a reverse mechanism for reversing a vehicle at a relatively low speed and a sophisticated transmission gear train for reversing the vehicle at an extremely low speed to a second transmission shaft. A method for selectively connecting a series of gears to the second transmission shaft is provided. Go backwards 5! The object of the present invention is to provide a new transmissive 7jc of the type mentioned at the outset, which is incorporated in such a way as to be able to operate the system without sacrificing the compactness of the transmission and without substantially complicating the structure. .

In order to solve the above-mentioned problems of the invention, the present invention provides a gear type transmission as described at the beginning, in which a tooth i for the lowest speed gear among the plurality of gears on a first transmission shaft is provided.
is loosely fitted to the first transmission shaft, and can be selectively coupled to the second transmission shaft by N-dynamic displacement operation of the speed change means, and 7'CI reverse gears are connected to the second transmission shaft. A supporting shaft is installed in the transmission case with a loose fit on the shaft, parallel to the first and second transmission shafts, and a large gear and a small gear are provided on this supporting shaft to rotate integrally with each other. Of the gears, the large gear meshes with the small gear fixedly installed on the wJl transmission shaft and the reverse gear on the second transmission shaft, and the small gear on the support shaft.

It is characterized in that it meshes with a human gear loosely installed on the first transmission shaft to rotate integrally with the above-mentioned gear for the lowest speed gear.

According to this configuration, the reverse gear installed loosely on the second transmission shaft is connected to the first transmission shaft, and the small gear fixedly installed on the first transmission shaft and the above-mentioned pinion on the support shaft are connected to each other. Through large gears,
The transmission is decelerated by a gear reduction mechanism consisting of these small gears and large gears, and is rotated at a concave rotation speed in the opposite direction to the series of transmission gears on the second transmission shaft. Therefore, the vehicle can be moved backward at a relatively low speed by displacing the gear shift means and working on its clutch portion to couple the reverse gear to the second transmission shaft.

In addition, in the above structure, the gear for the lowest speed gear on the first transmission shaft is installed in the first transmission field that supports it relatively rotatably, and the above-mentioned small gear is fixedly installed on the first transmission shaft. The first gear reduction mechanism consists of a gear and the large Fj11 gear on the above-mentioned regular shaft, and the second gear reduction mechanism consists of the small gear on the above-mentioned support shaft and the gear for the lowest speed. It is decelerated and rotated. Then, depending on the rotation of the lowest speed gear on the first transmission 'Jh@, the large diameter lowest speed gear on the second transmission shaft that meshes with it is further decelerated and rotated at the next rotation speed. Therefore, if the latter tooth i is connected to the gear shift means and the second transmission shaft, the vehicle will be able to run at an extremely low speed.Thus, the box transmission according to the present invention has a simple structure. A speed change means 77 for selectively connecting a series of speed change gears on a second transmission shaft to a reverse mechanism for reversing #i4 at a relatively low speed; the! In addition, a significantly lower tonne speed can be obtained by operating the lowest gear without reducing the vehicle speed obtained by operating the higher gear.

And this invention does not sacrifice the compactness of the transmission. This is because first, install the lowest quick-acting tooth (chisel) on the first transmission oil with a loose fit, and then
Since the driving shaft is rotated at low speed through two sets of reduction gears, it is possible to obtain an extremely low speed by operating the lowest gear without reducing the deceleration on the high gear side. Therefore, it is no longer necessary to increase the distance between the first and second transmission shafts. Of the 2 sets of 14 reduction gears for decelerating and rotating the gear for the lowest gear on the first transmission shaft, one set of gear reduction mechanism is for reverse gear on the second transmission shaft. Since it also serves as a reduction gear dovetail groove for rotating the regular electric current at a low speed, the number of additionally provided T gears is small, and the space occupied by the above-mentioned spindle and additional teeth I is extremely small.

As described above, the structure in which one set of reduction gears is used to reduce the rotation speed of two gears is a simple structure that achieves reduction in speed of the two gears with a small number of gears. As described above, the gear shift means for selectively connecting the series of gear teeth Eliminates the need for a separate clutch. These facts mean that the invention does not substantially complicate the structure of the transmission.

Embodiment: A reverse gear is added to the second series of gears to achieve multi-stage gear change on the second transmission shaft, and the reverse gear is also machined into the same speed change shift means as the gear. 2. The structure that is attached to the second transmission shaft increases the shift range of the transmission shift means. an elongated sliding member formed on the outer circumferential surface of the shaft in the same manner as the line and slidably fitted in at least one slot, and connected to the base end of the sliding member in a relatively non-slidable manner; a shifter sleeve disposed on the second transmission shaft; a clutch member rotatably supported at the distal end of the sliding member within the slot and forming the general clutch portion; a spring that rotates and urges the portion to protrude outside the second transmission shaft;
It is appropriate to configure it accordingly. According to this structure, the only part that rotates in the speed change shift means during a shift operation is the clutch member, which can be of short length, so that even when the speed change shift means is moved to any operating position within a wide range, In other words, the clutch portion remains constant and moves out of the second transmission shaft in a first-class manner, making it possible to reliably and stably connect the 1m vehicle on the second transmission shaft to the transmission shaft. .

The neutral position of the transmission mechanism is preferably set between the lowest gear position and the reverse position so as to reduce shock when starting and stopping the vehicle.

Therefore, in another embodiment of the present invention, the threshold between the lowest speed gear on the second transmission shaft and the reverse gear
A collar is installed on the transmission shaft to prevent the clutch portion from protruding outside the second transmission shaft, and the clutch portion comes into contact with the inner circumferential surface of the collar. ttt Set the transmission mechanism to the neutral position. This structure is the simplest in providing a neutral position at a desired location.

It is another embodiment to provide the differential device in the transmission according to the present invention with a simple structure.Therefore, the left and right differentials are arranged concentrically to connect the second transmission shaft to the left and right final travel drive means. An output shaft is provided in a position close to the second transmission shaft, parallel to the second transmission shaft, and protrudes outward from inside the transmission case, and a differential device is disposed between the left and right output shafts. , is achieved by meshing the large input gear of this differential device with the small output gear fixedly installed on the second transmission shaft. This structure provides direct input to the differential gear from the second transmission shaft, which is rotated at variable speeds, and minimizes the number of gears for input transmission.

In an additional embodiment of the invention which aims to ensure compactness of the two-piece transmission while providing such a differential, the plurality of gears on the second transmission shaft are arranged such that the plurality of gears on the second transmission shaft are
A gear is positioned so that it overlaps the differential when viewed in the axial direction of the differential, and has a larger diameter toward one of the output shafts on the right side of the recording gear. , and the differential case of the differential device,
The case Ic has a shape in which the diameter gradually decreases toward the direction of the one output shaft. Take a look at the multiple transmission gears on the V-2nd transmission and oil in the direction of the field line!
Setting the diameter of the gear wheel, setting the shape of the differential case in the differential gear, and adjusting the l/c, avoiding interference between the multiple gear shifting gear and the differential case, and overlapping a series of shifting gears in the differential gear. Do: Position the transmission shaft and differential gear = 1
This reduces the width of the transmission seen in the 4tl line direction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment shown in the drawings relates to one example of carrying out the present invention in a small self-propelled work as shown in FIG. This work vehicle is equipped with a mower at the bottom of the center of the body and is said to be effective for mowing work.

An engine 11t, which is a driving source, is installed at the front of the four bodies, and a transmission case 12, which houses a transmission according to the present invention, is installed at the rear of the body. Left and right υ extending left and right from the mission case 12 yen
Output shafts 13L and 13R are provided, and left and right rear wheels 14L and 14R for running the vehicle are connected to the output shaft 13L.
, 13R. The transmission case 12 is provided with a vertical input shaft 15t extending upward, and this input shaft 15 is connected to a gooley 17 on the nearsin output shaft 16 and a boo! on the input shaft 15. It is interlocked and connected to the engine 11 by a belt 19 wound around J-13.

A passenger seat 20 is installed on the fuselage, and a control handle 21 is placed in front of the passenger seat 20. The wind vehicle is controlled by turning the left and right cutting wheels 22 on the control handle 21.
Ru.

As shown in the diagram, the minition gauge 12 is made by abutting the left and right cases 12L and 12R and connecting the bolts 231 with a trowel to form a 21-9 degree Celsius. Valve and support the bearing. Pressure stone output @L8L, 13R is left and right case 12L, 12R
A supporting cylinder part 12a protruding to the right is integrally formed, and each cylinder part 12a is supported via a pair of ball bearings.
It is. As shown in Fig. 1.8, the transmission case 12 has a first driving shaft 24 and a second transmission shaft 25 that are parallel to the constant output +11113L and 13H. (OR-A/Hair 1
The J y ft valve is supported and installed.

Of the two transmission shafts 24 and 25 described above, the first transmission shaft 24 is placed close to the human power shaft 15, and this first transmission shaft 24 is connected to the human power shaft 15 by A small umbrella table 25 integrally formed with the large bevel gear 27t fixedly installed on the first transmission @ 24 is meshed with the large bevel gear 27t and connected in a fast interlocking manner. The second transmission shaft 25 is the left and right output shafts 13L, I3
The left and right outputs and other 13L are arranged on the side close to H, and are arranged concentrically with each other.

A differential device 28 receiving input transmission from the second power transmission shaft 25 is disposed between 13R and 13R. Disposed between the first transmission shaft 24 and the second transmission shaft 25 are a transmission groove, which will be described later, which performs a five-speed gear change, and a reversing mechanism, which will be described later, which selectively moves the vehicle backward. One end of the second transmission shaft 25 extends outside the mission case 12, and is expanded and engaged in friction by rotating the cam sleeve 29c against the playing drum 29b fixedly installed on the extended end. Matching brake shoe 29
A brake 29 having a diameter of 7 and a diameter of 7 is installed on the outer surface of the mini-john case for selectively braking the entire vehicle.

As shown in Fig. M1, a 7″L
tLt speed change, nine series of teeth are provided on the first transmission shaft 24 with no gaps! 80, 31, 32, 33° 84 and a series of gears 35, 36, 37.3 & 39, which are electrically connected to the second transmission shaft 25 through a ring with almost no gaps, and mesh with each other in five rows of transmission gears. It has columns. All of the 35-19Vi on the second transmission @25 are loosely fitted into the second transmission a shaft 25, and all of these ff135-39 are connected to the speed change shift means described later. By being uniformly connected to the second transmission shaft 24, each transmission gear train is selectively activated.

The gears 30, 81, 32, 38 of the fixed series of defining sections 30-34 installed on the first drive field 24 are fixed to the transmission field 24 by spline fitting.

It is provided for the lowest speed gear for Kohachi and 11i! In particular, the gear 34 of the sleeve bearing 40
It is loosely fitted onto the first power transmission shaft 24 via. 'E
A reverse gear 41 is loosely fitted to the 94S2 transmission shaft 25 through a companion collar 50, with a gear 39 for the lowest speed gear being spaced 1111 degrees apart. Furthermore, a short support @42 parallel to the transmission @Q"A24.25 is fixed to a support cylinder portion 48 formed on the mission case wall with a support pin 44, and is provided inside the mission case 12. A large gear 45 and a small gear 46, which rotate integrally and have a common boss portion, are loosely fitted on the shaft 42 through a sleeve bearing 4ft.The support shaft 42 is connected to both transmission shafts as shown in FIG. A small gear 48, which is provided at a fixed position laterally at a distance from both transmission shafts 24 and 25 between 24 and 25, and meshes with a large gear 45 on this support shaft 42, is connected to the first transmission shaft 24. It is fixedly installed on the top by spline fitting, and the above-mentioned large gear 45
is simultaneously meshed with the reverse gear 41 on the second transmission shaft 25, as clearly shown in Figure $4. And on the first transmission shaft 24? C further gear 34.48 darkness and canine east 49,
The two gears that rotate integrally with the gear 34 share a common boss and are loosely fitted through the sleeve bearing 40, and the small gear 46 on the support shaft 42 meshes with the canine teeth X49. Therefore, WJ2 The reverse gear 41 on the transmission shaft 25 is the first
The transmission shaft 24 is rotated at a relatively low rotation speed via a gear reduction mechanism consisting of a small gear 48 on the first transmission shaft 24 and a large gear 45 on the support shaft 42. This backward tooth Jt4
1 rotation direction is a series of transmission gears 3 on the second transmission shaft 25.
7, contrary to the rotation direction of 5-39! -9, the rotation direction of the new number is in the forward direction of the vehicle, and the rotation direction of the former is in the backward direction of the vehicle,
Each is set. The gear 34 for low-speed shifting on the first transmission shaft 24 is connected to the gear 48 by the transmission shaft 24.
．． The above-mentioned gear reduction mechanism with 45 machining, the small gear 46 on the support shaft 42, and the small diameter 'tlI teeth J [4] are machined into the gear reduction mechanism described above, and are reduced in two stages and rotated at a low speed. Rotates at the number of revolutions. m1L3 for the large diameter lowest speed gear with this refined second transmission shaft 25! j is further decelerated by one rotation of the gears 34 and 89, and continues to rotate at an extremely low rotation speed.

Transmission mechanism and reverse gear 41! The series of transmission gears 135-89 and the reverse gear 41 on the second transmission shaft 25 are alternatively coupled to the second transmission@25, and the left and right rear wheels 14L, 14 are connected to the second transmission @25.
The second transmission shaft 25, which is interlocked and connected to the R, is configured to selectively change gears and rotate backward.

Each gear 35° loosely installed on the second transmission shaft 25: (6
The inner peripheral surfaces of the bosses 137, 88, 89, and 41 are provided with gears 89.4 and 89.4, respectively, as shown in FIG. 8 for the gear 35.
As shown in Fig. 1.1, four slots 53 are formed with a phase difference of 90 degrees. phase difference f
cj? -tl pairs of slot holes 52 are formed overflowing in the axial direction of the transmission shaft 25. Each slot 52 has a slot 5 in which each tooth 1L35-39.41 protrudes outside the second transmission shaft 25.
3. The gears can be coupled to the second transmission shaft 25 by entering the latch portion 53at-tl, and the gear shift means of the set 53a is slidable along the axial direction of the second transmission shaft 25. possible.

As clearly shown in FIG. 6, each gear shift means is slidably fitted into a slot 52 and is slidably fitted into a slot 52, as shown clearly in FIG. : A plate-shaped clutch member 53 is rotatably connected and supported along the radial direction of the second power transmission shaft 25 by a pin 55 at the tip of an elongated plate-shaped sliding member 54, and the clutch portion 6aa is connected to this clutch member. A protrusion is formed on the outer surface of the free end of 53. A slot 53b that is long in the axial direction is formed on the inner surface of the clutch member 53, and the inner bottom surface of the slot 53b is rotatably biased at both ends in the direction of protruding outside the engagement transmission shaft 25. .

Therefore, when the clutch portion 53a of the rainbow clutch member 53 is moved to a position facing the boss portion of each gear 35-39°41 by the sliding operation of the sliding member 54, the chain line in FIG. The clutch member 53 is rotated outward in the radial direction by the biasing force of the spring 56, and the clutch portion 53a plunges into the gear slot 53 so that all the gears are connected to the second transmission shaft 25.
It is connected so as to be non-rotatable relative to the other. In addition, the slot 53 of each gear
, is formed to have a circumferential width slightly larger than the width of the clutch portion 53a, as shown in FIG.

As shown in FIG. 1, a protrusion 54a protruding in the radial direction is formed at the base end of the sliding member 54, and a shifter sleeve 57 has an annular slot on its inner circumferential surface into which the protrusion 54a is fitted. , is slidably provided on the second transmission shaft 25. Therefore, the shifter sleeve 57 cannot slide relative to the sliding member 54.

The shift operation mechanism in Fig. 7 shows the shifter sleeve 57 at the ■-■ line position in Fig. 1! The shifter sleeve 57 is slid and the sliding member 54 is slid in the axial direction of the second transmission shaft 25. This is a picture of the elaborate shift operation mechanism for displacement.

The mission case 12 has an operating shaft 5 along the vertical direction.
A shift lever 60 is attached to the outer end of the operating shaft 59. This shift lever 60 extends to a side position of the passenger seat 20, as shown in FIG. M2.

As shown in FIG. 7, the operating shaft 5 is
9 is fitted with a cylinder 61 and fixed to the pin 62,
A shift fork 63 and a detection plate 64 are welded to this cylinder 61.

A pair of left and right bins 65 are welded and fixed to the lower end of the shift fork 63 that is twisted around the shifter sleeve 57.
7a, and the shifter sleeve 57 is slid in the axial direction on the second transmission shaft 25 by rotation of the shift fork 68 due to rotational displacement of the operating shaft 59. The detent plate 64 has seven detent holes 66 on its free end side as shown in FIG.
R, 66N, 661, 66■, 661 [, 66f to 66
The Vk gears are loosely fitted onto the second transmission shaft 25 in this order from one end to the other end, and are formed at intervals of t corresponding to the installation intervals of the plurality of gears. The hollow bolt 6 is positioned facing the free end side of the detent plate 64 in the mission case 12.
7 and supported by this hollow bolt 67.
A ball 69 that is biased to move in the direction of protrusion 19 is provided in the spring 68 in the detent plate 64, L, It at the position where the ball 69 projects into each detent hole 66R-66V of the detent plate 64. The shift fork 63 is releasably restrained in position.

As can be seen from Figure 1, the transmission gear train between the two transmission shafts z4tz5 is arranged so that from the right side to the IE side, the one for the lowest gear, then the one for the highest gear. 2. It works after masturbation! 11141 is located on the right side of the gear train of the lowest speed gear, with the collar 50 at a distance. The collar 50 has a speed changer 7 on its inner peripheral surface.
A neutral position is set between the lowest speed gear and the reverse gear when the clutch portion 53a of the toe means comes into contact with the clutch portion 53a, thereby making the clutch portion 53a incapable of protruding.

Correspondingly, the detent holes 66R-66V of the detent plate 64 shown in FIG. Detent hole 661 for 2nd speed position, Detent hole 66■ for 3rd speed position, Detent hole 66f for 4th speed position, Detent hole 66V for 5th speed position.
It is said that When the shift fork 68 is rotated, the tent plate 64 is rotated between the two extreme positions shown in chain lines in FIG.
9 will rush in with Suzuring 68's auxiliary force, preventing an unexpected automatic shift from occurring.

A switch operating pin 71 shown in FIGS. 7-9 is attached to the temporary detent 64, and when the detent plate 64 is rotated to the neutral position, it is pushed by the operating pin 71 and turned on. A neutral detection switch 72 is screwed onto the transmission case 12 as shown in FIG. This detection switch 72 is inserted into an engine starter circuit (not shown), and is used as a first step to ensure safety by allowing the engine 11 to be started only when the transmission is in a green state.

As shown in FIGS. 1 and 3, the differential shelving device 8 is fixedly supported on the differential case 74 with a pin 75 and supported on a ft-differential yoke @76. The left and right output shafts 13L, l<R are spline-blown fc, and are meshed with a pair of trigger umbrellas tJA car 78.The differential case 74 is formed with one end open, and the open part is It is closed by a human input gear 801C fixed to the differential case 74 with bolts 79, and while the second transmission shaft 25 is located close to the differential gear 28 as described above, the second transmission shaft 25 small output gear 81
The small output gear 81 meshes with the large input gear 80 □ As shown in Figures i and io, the differential case 74 extends from the left side to the right side, one end surface of the boss portion of the large input gear 80. The seven 79 parts 74a that fit into the upper circular groove, the large diameter part 74b where the differential yoke shaft 76 is located, and the right driven heavy duty I! 78 is located, and a small diameter part 74d is where the post cylindrical part of the dorigun bevel gear 78 is located, and the diameter fe gradually decreases toward the right output shaft 13R direction. It is formed in the case.

On the other hand, a series of transmission gears 85-39 on the N2 transmission shaft 25 located close to the differential 28 overlaps the differential 28 when viewed in the axial direction of the differential 28, as shown in FIG. It is arranged like this.

Also, on the second transmission shaft 25, the gear on the lower speed stage side, that is, the gear with a larger diameter, is arranged on the far right side.

In other words, the gear shift means 5 is slidably operated in the axial direction.
In order to make the second power transmission shaft 25fe as short as possible, which inevitably becomes long due to the arrangement of the gear 35-3.
9, fc[i! Setting the diameter, setting the shape of the differential case 74, and lc! 5, l@135-3
In order to prevent interference with the differential case 74 even if the 9t'' differential gear 28, !j-- is para-lugged, the second transmission @ 25t- is shortened as an overlap arrangement. ◎ 75p/ji part 7 of the 1-sea differential case 74 shown in Fig. 10
4aK forms a mounting seat having a screw hole 83 for screwing the bolt 79, and the insertion hole 84 for the bottle 75 is a slot cut into the large diameter portion 74b from the right end. is drilled from the inner end surface of the large diameter portion 7 in a corresponding phase.
4b is formed with an insertion hole 85 for the single shaft 76. As shown in FIG. 1, the ball bearing 86 that supports the left end of the differential case 76 and the inner end of the left output shaft 13L is mounted on the boss cylindrical part of the large input*jE80.
The ball bearing 87 that supports the right end of the differential case 76 and the inner end of the right output shaft 13R is a small diameter support portion 74 formed at the end of the small diameter portion 74d of the differential case 74.
e, and are supported by the mission case 12.

The transmission shown in the figure is M2, and the shift lever shown in Figure 7 is 6of7t: IJ! The sliding member 54 and the clutch member 53t are slid in the axial direction of the second transmission shaft 25 to shift the clutch portion 53.
a K J: Selectively connects any one of the gear shifting gear f$: d5-39 and the reverse gear 41 to the second transmission shaft 25, and changes the vehicle speed to 5th gear in the forward direction. The rotational speed difference between the left and right rear wheels 14L and 14R, which is necessary when the vehicle is turning at zero and allows the vehicle to selectively move backward at low speed, is provided by the differential gear [28] in a normal manner.

Since the clutch portion 53a of the speed change shift means protrudes outside the second transmission shaft 25 due to the rotation of the clutch member 53 around the pin 55, any of the gears 35- which are loosely fitted on the second transmission shaft 25. 89.41 protrudes, and allows each of the gears to be stably and reliably connected to the second transmission shaft 25. The minimum vehicle speed obtained by coupling the gear 35 to the second transmission @25 is extremely low considering the aforementioned three-stage speed between the two transmission shafts 24 and 25. @Q vehicle speed is suitable when a high load is applied to the vehicle, such as when mowing grass that has grown excessively and has become cracked, or when performing tillage work while towing a tilling device with a small work vehicle. ing.

As can be seen from FIG. 1, the transformer and transmission are extremely compact, and the inside of the transmission case 12 is effectively utilized to avoid leaving any unnecessary space. The illustrated transmission is therefore particularly suitable for use in relatively small self-propelled work vehicles.

[Brief explanation of the drawing]

Fig. 1 is a developed vertical cross-sectional view of a transmission case of a self-propelled working vehicle equipped with a transmission according to the present invention, Fig. 2 is a perspective view schematically showing the above-described self-propelled working vehicle, and Fig. 8 is a Partially omitted vertical sectional view overflowing the I-M line in Figure 1, 44
The figures are a perspective view showing the meshing relationship of the main gears of the transmission shown in FIG. 1, and FIG. Part 6 of the speed shifting means
The figure is a partial cross-sectional plan view of a part of the speed change shift means shown in FIG. 5, and FIG. 7 is an enlarged sectional view taken along the line ■-■ in FIG. Sumono, No. 81
'W Fi,'! ! 7 is a sectional view taken along the line ■-■ in FIG. 7, and FIG. 9 is a sectional view taken along the line IK--■ in FIG. FIG. 1θ is a perspective view showing a differential case of a t-differential device installed in the transmission shown in FIG. 1. 11... Engine, 12... Mitsushimi/Case, 1
3L, IIR...For output, 14Lt14R...Rear wheel (R final travel drive means), 15...Input shaft, 19...
Belt, 24... IGL transmission shaft, 25... Second transmission shaft, 28... Differential device, 30, 31.82, 33.8
4...Gear, 85.36. B'7e 88.89・
... Gear, 41 ... Reverse gear, 42 ... Support shaft, 4
5... Large tooth layer, 46... Small gear, 48... Small gear, 49... Large gear, 50... Collar, 53,...
Slot hole, 52... Slot hole, 53... Clutch member, 53
a...Clutch portion, 54...Sliding member, 55...
Bin, 56... Leaf spring, 57... Shifter sleeve, 59... Operation fH1+, 6o... Shift lever-16
8...Shift 7 oak, 64...Detent plate, 65
... Bin, 66R, 66N, 661.6611, 66
11, 66■, δ6v...detent hole, 68...spring, 69...ball, 74...differential case,
74a...2 parts of flannel, 74b...large diameter part, 74c
... Medium diameter part, 74d... Small diameter part, 80... Large input gear, 81... Small output gear O Fig. 3 Fig. 2 Fig. 7θ Fig. 5

Claims (1)

[Claims] 1. Between a first transmission shaft and a second transmission shaft, which are provided in parallel to each other in the transmission case, the transmission shaft is rotatably driven by the first transmission shaft on the first transmission shaft. A plurality of gears and a second
A plurality of transmission gear trains are provided in which a plurality of gears are loosely fitted on a transmission shaft and meshed with each other, and the gears on the second transmission shaft protrude in a radial direction from within the second transmission shaft. 1
A speed change means having a clutch portion for selectively coupling the transmission gear to the second transmission shaft is provided in the second transmission shaft so as to be slidable along the axial direction, and the first transmission shaft is connected to the engine and This is a transmission for a self-propelled work vehicle in which two transmission shafts are interlocked and connected to left and right final travel drive means, respectively, and the plurality of gears (3) on the first transmission shaft (24)
0, 31, 32, 33, 34) is provided by loosely fitting the gear (34) for the lowest speed gear on the first transmission shaft (24), and the sliding gear of the gear shift means (53, 54) One reverse gear (41), which can be selectively coupled to the second transmission shaft (25) by dynamic displacement operation, is attached to the second transmission shaft (25).
), and the first and second transmission shafts (24, 2
5), connect the support shaft (42) parallel to the mission case (1
2), and a large gear (45) and a small gear (46) that rotate integrally with each other on this support shaft (42) are provided, and among these gears (45, 46), the large gear (45) The small gear (48) fixedly installed on the first transmission shaft (24) and the reverse gear (41) on the second transmission shaft (25) mesh with each other, and the pinion on the support shaft (42) Small gear (4
6) is meshed with a large gear (49) which is loosely fitted on the first transmission shaft (24) so as to rotate integrally with the gear (34) for the lowest speed gear mentioned above. transmission. 2. The transmission according to claim 1, wherein the speed change shift means is connected to a second transmission shaft (25).
An elongated sliding member (54) slidably fitted into at least one slot (52) formed along the axial direction on the outer peripheral surface of the
), a shifter sleeve (57) provided on the second transmission shaft (25) and connected to the proximal end of the sliding member (54) in a relatively non-slidable manner; Moving parts (54
) is rotatably supported at the tip of the clutch portion (53a
), and a spring (56) that rotationally biases the clutch member (53) in a direction in which its clutch portion (53a) protrudes outside the second power transmission shaft (25). A transmission characterized by being configured with the following. 3. The transmission according to claim 2, wherein the spring is a leaf spring (56) that slides into contact with the inner bottom surface of the slot (52) and engages with the clutch member (53). A transmission characterized by comprising: 4. The transmission according to claim 1 or 2, in which the lowest gear gear (39) on the second transmission shaft (25) and the reverse gear (41) A collar (50) that disables the clutch portion (53a) from protruding outside the second transmission shaft (25) is installed between the second transmission shaft (25) and the collar (50). A transmission characterized in that the position of the speed change shift means (53, 54) with which the clutch portion (53a) comes into contact with the inner circumferential surface of the transmission is set at a neutral position of the speed change mechanism. 5. The transmission according to claim 1, wherein the second transmission shaft (25) is connected to the left and right final travel drive means (14L, 14R) by mutually concentric left and right drive means (14L, 14R). Output shafts (13L, 13R) are provided so as to be located close to the second transmission shaft (25), parallel to the second transmission shaft (25), and protrude outward from the inside of the mission case (12). A small output device is constructed by disposing a differential device (28) between the output shafts (13L, 13R) and fixing the large input gear (80) of this differential device (28) on the second transmission shaft (25). A transmission characterized by meshing with a gear (81). 6. The transmission according to claim 5, wherein the plurality of gears (
35, 36, 37, 38, 39) to the differential gear (2
The left and right output shafts (13L, 13
R) so that the gear with a larger diameter is positioned toward the output shaft (13R), and
A transmission characterized in that the differential case (74) of the differential device (28) is formed into a case whose diameter gradually decreases toward the one output shaft (13R).