JPH0840319A - Transmission for small sized agricultural machine - Google Patents

Abstract

PURPOSE:To attain main speed change reverse two shifts without enlarging size of a transmission case by arranging a high speed reversing speed change gear in parallel to a low speed reversing speed change gear in an upper space of a subspeed changing select slide gear. CONSTITUTION:A high speed reversing speed change gear 32 is provided integrally with a back shaft 10 in upper space of a subspeed changing select slide gear 16, that is, in vacant space provided leftsideward a low speed reversing speed change gear 29. The high speed reversing speed change gear 32 is formed so that it can be selectively meshed with a large diametric gear part 22a of the first select slide gear 22 used in a high speed forward speed change condition. Consequently, a high speed reversing speed change condition, transmitting power of a main speed change shaft 9 to a subspeed change shaft 11 via the large diametric gear part 22a of the first select slide gear 22, high speed reversing speed change gear 32, small diameter relay gear 28 and an intermediate speed forward speed change gear 25, can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a small agricultural machine mounted on a walk-behind management machine or the like.

[0002]

BACKGROUND OF THE INVENTION Generally,
Some small agricultural machines of this type have a main transmission mechanism and an auxiliary transmission mechanism incorporated in a transmission to enable multi-stage gear shifting. For example, in a walk-behind management machine, the total number of gear stages of the main transmission mechanism is four. (2 forward, 2 reverse
Generally, the gears are set in three stages, or three stages forward, and one stage backward. Therefore, there are the following drawbacks. That is, in the case of the two forward speeds and the two reverse speeds, the output speed as shown in FIG. 5 (A) can be selected, but in this case, the intermediate speed (about 60 rpm) suitable for the deep-cultivation rotor work is selected. The number of rotations is insufficient for weeding rotor work that requires high-speed rotation (about 120 rpm), which cannot be selected.
There was a waste of excessive high speed rotation (about 80 rpm) set in reverse gear. On the other hand, 3 forward steps,
The output speed can be selected as shown in Fig. 5 (B) for the one-stage reverse drive, but with this one, the maximum rotation speed (about 15 rpm) during reverse drive is too slow, so the steering wheel can be reversed. However, there is a drawback in that it takes a long time to move the machine body (non-working traveling) when performing the work by reducing the work efficiency. Therefore, it is proposed to configure the main transmission mechanism to have three forward gears and two reverse gears to eliminate the above-mentioned problem.
Since it is necessary to increase the number of transmission gears, there are inconveniences that the transmission case becomes large (widened) and the cost is significantly increased.

[0003]

SUMMARY OF THE INVENTION The present invention was devised with the object of providing a transmission for a small agricultural machine capable of eliminating these drawbacks in view of the above-mentioned circumstances. Of the main transmission shaft on which the first selection sliding gear and the second selection sliding gear are mounted, and an auxiliary transmission shaft on which the sub-selection sliding gear for sub-transmission is mounted, and above the auxiliary transmission shaft. , A back shaft is arranged via a constant mesh gear, and both ends of the auxiliary transmission shaft are selectively meshed with a large-diameter gear portion of the first selection sliding gear to transmit high-speed forward power to the auxiliary transmission shaft. A high-speed forward transmission gear and a pair of medium- or low-speed forward transmission gear that selectively meshes with the second selection sliding gear and transmits medium-speed or low-speed forward power to the auxiliary transmission shaft are arranged in a distributed manner, while the back shaft is arranged. For the middle part of the, select the small diameter gear part of the first selection sliding gear. In a transmission for a small agricultural machine in which a transmission gear for low speed reverse drive for transmitting low speed reverse drive power to an auxiliary transmission shaft is arranged, in a space above the selective sliding gear for auxiliary shift, parallel to the low speed reverse transmission gear. And a high-speed reverse power transmission gear is arranged, and the high-speed reverse power is transmitted to the auxiliary transmission shaft based on the selective meshing between the high-speed reverse gear and the large-diameter gear portion of the first selection sliding gear. To do. With this configuration, the present invention makes it possible to make the main gear shift to two reverse stages without increasing the size of the transmission case, and to make the large-diameter gear portion of the first-selection sliding gear used during high-speed forward travel to the high-speed reverse drive. This is also used at times to minimize the increase in the number of parts.

[0004]

Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 is a walk-behind management machine, and the walk-behind management machine 1 includes a frame 2 having hitch portions 2a for connecting working machines at both front and rear ends thereof, and an engine 3 mounted at a front portion of the frame 2. , A transmission 4 mounted on the rear portion of the frame 2, a belt transmission mechanism 5 for transmitting engine power to the transmission 4, an axle 6 penetratingly supported by the lower end of the transmission 4, and a wheel mounted on the axle 6. 7, a handle 8 which can be turned upside down, etc., but the basic structure of each of these is the same as before.

The transmission 4 includes a main transmission shaft 9 also serving as an input shaft, a back shaft 10 located behind the main transmission shaft 9, and a sub transmission shaft 1 located below the back shaft 10.
1. Sub-transmission driven shaft 12 located in front of the sub-transmission shaft 11
Etc. are supported in parallel, but the power transmission path from the main transmission shaft 9 to the sub transmission shaft 11 is constituted by the main transmission mechanism 13, while the sub transmission shaft 11 to the sub transmission driven shaft 12 are provided.
The power transmission path to the sub-transmission mechanism is constituted by the sub-transmission mechanism 14, and the power transmitted to the sub-transmission driven shaft 12 via the main transmission mechanism 13 and the sub-transmission mechanism 14 is transmitted via the transmission chain 15 to the axle. It is supposed to be transmitted to 6.

The sub-transmission mechanism 14 includes a sub-transmission selection sliding gear 16 which is spline-fitted to an intermediate portion of the sub-transmission shaft 11.
Sub-transmission high-speed drive gear 17 rotatably provided at the left end of the sub-transmission shaft 11, and sub-transmission high-speed driven gear 1 integrally provided on the sub-transmission driven shaft 12 so as to always mesh with the gear 17.
8. A sub-speed low speed driven gear 19 and the like integrally provided on the sub-speed driven shaft 12 so as to be parallel to the gear 18. Then, in a state in which one gear portion 16a of the sub-transmission selection sliding gear 16 is selectively meshed with the sub-transmission low-speed driven gear 18 (sub-transmission low-speed state L), the power of the sub-transmission shaft 11 is greatly decelerated and While the power is being transmitted to the speed-change driven shaft 12, the other gear portion 16b of the sub-speed selection sliding gear 16 is selectively meshed with the internal gear portion 17a of the sub-speed high-speed drive gear 17 (sub-speed high-speed state H). The power of the auxiliary transmission shaft 11 is decelerated by a small amount and transmitted to the auxiliary transmission driven shaft 12. Reference numeral 20 denotes an auxiliary gear shift operation mechanism for slidingly operating the auxiliary gear shift selection sliding gear 16 with an auxiliary gear shift operation lever 21.

On the other hand, the main transmission mechanism 13 has a large diameter of the first selection sliding gear 22, the second selection sliding gear 23, and the first selection sliding gear 22 for main transmission which are spline-fitted to the main transmission shaft 9. A high-speed forward transmission gear 24 integrally provided on the left end portion of the auxiliary transmission shaft 11 to selectively mesh with the gear portion 22a, and a right end portion of the auxiliary transmission shaft 11 to selectively mesh with the second selection sliding gear 23. And a low speed forward transmission gear 26 rotatably provided at the right end portion of the auxiliary transmission shaft 11 so as to selectively mesh with the medium speed forward transmission gear 25 and the second selection sliding gear 23. A large-diameter relay gear 27 integrally provided on the right end of the back shaft 10 so as to always mesh with the small-diameter gear portion 26a of 26, and an integral right end of the back shaft 10 so as to always mesh with the medium-speed forward transmission gear 25. Small-diameter relay gear 28, the first Small selection slide gear 22 gear portion 22
It is composed of a low-speed reverse gear shift gear 29 and the like integrally provided in the intermediate portion of the back shaft 10 so as to selectively mesh with b.
That is, the power of the main transmission shaft 9 is transmitted to the sub transmission shaft 11 via the large-diameter gear portion 22a of the first selection sliding gear 22 and the transmission gear 24 for high speed advance, and the high speed forward transmission state F3 and the second Medium-speed forward shift state F2 in which transmission is made to the auxiliary transmission shaft 11 via the selective sliding gear 23 and the medium-speed forward shift gear 25.
A second selection sliding gear 23, a low speed forward transmission gear 26,
Small diameter gear portion 26a, large diameter relay gear 27, small diameter relay gear 2
8 and the auxiliary transmission shaft 1 via the medium speed forward transmission gear 25.
The low speed forward speed change state F1 transmitted to 1, the small diameter gear portion 22b of the first selection sliding gear 22, the low speed reverse speed change gear 29,
The small-diameter relay gear 28 and the medium-speed forward transmission gear 25 are configured to be capable of performing a speed change operation to a low speed reverse speed change state R1 which is transmitted to the auxiliary speed change shaft 11. Reference numeral 30 denotes a main shift operating mechanism for slidingly operating the first selection sliding gear 22 and the second selection sliding gear 23 with the main transmission operating lever 31.

Further, reference numeral 32 is a high-speed reverse transmission gear added according to the present invention. The high-speed reverse transmission gear 32 is a space above the auxiliary transmission selection sliding gear 16, that is, a low-speed reverse transmission. It is provided integrally with the back shaft 10 in an empty space on the left side of the gear 29. Then, the high-speed reverse shift gear 32 is the first selection sliding gear 22 used in the high-speed forward shift state F3.
Since it is formed so as to be selectively meshable with the large-diameter gear portion 22a of
The power of the main transmission shaft 9 is supplied to the large-diameter gear portion 22a of the first selection sliding gear 22, the high-speed reverse gear 32, and the small-diameter relay gear 28.
And the auxiliary transmission shaft 11 via the medium speed forward transmission gear 25.
It enables a high speed reverse gear shift state R2 that is transmitted to the vehicle.

In the embodiment of the present invention configured as described above, the main transmission mechanism 13 includes the auxiliary transmission shaft 11 via the large diameter gear portion 22a of the first selection sliding gear 22 and the high speed forward transmission gear 24. A high speed forward speed change state F3 transmitted to the sub speed change shaft 11 via a second selection sliding gear 23 and a medium speed forward speed change gear 25;
A low speed transmitted to the auxiliary transmission shaft 11 via the second selection sliding gear 23, the low speed forward transmission gear 26, the small diameter gear portion 26a, the large diameter relay gear 27, the small diameter relay gear 28 and the medium speed forward transmission gear 25. Forward shift state F1 and first selection sliding gear 2
The second small gear portion 22b, the low speed reverse transmission gear 29, the small diameter relay gear 28, and the medium speed forward transmission gear 25 are transmitted to the sub transmission shaft 11 to the low speed reverse transmission state R1 so that the speed change operation can be performed. However, since the high-speed reverse gear shift gear 32 is arranged by utilizing the empty space existing above the auxiliary shift selective sliding gear 16, the main shift reverse 2 stage without further expanding the outer shell of the transmission 4. Shifting is possible. Therefore, it is possible to maintain a compact transmission 4 while enabling main shifts of three forward gears and two reverse gears, and as a result, it is possible to minimize the cost of shifting to two reverse gears. It is not forgiving and can maintain a good appearance.

Moreover, since the large-diameter gear portion 22a of the first selection sliding gear 22 used during high-speed forward movement is selectively meshed with the high-speed reverse transmission gear 32, high-speed reverse transmission is performed.
There is no need to add selective sliding gear members or change the shape,
As a result, it is possible to reverse the vehicle by adding only the high-speed reverse gear 32.
It is possible to achieve a gear shift.

[0011]

In summary, since the present invention is constructed as described above, there is a high-speed forward state in which the large-diameter gear portion of the first selection sliding gear is selectively meshed with the high-speed forward transmission gear,
A medium-low speed forward state in which the second selection sliding gear is selectively meshed with a pair of medium- and low-speed gears, and a low-speed reverse state in which the small-diameter gear portion of the first selection sliding gear is selectively meshed with the low-speed reverse gear. A main transmission mechanism capable of changing gears is provided, and the power changed by the main transmission mechanism is further changed by an auxiliary transmission mechanism. Since the reverse gear is arranged in the space above the auxiliary shift selective sliding gear that constitutes the auxiliary gearshift mechanism in parallel with the low-speed reverse gear,
By making effective use of the space above the auxiliary sliding selective sliding gears, the main shift can be set to two reverse gears, and as a result, it is possible to perform three main shifts and two reverse gears. It is possible to avoid increasing the size of the transmission and thus avoid increasing the cost, and maintain a good appearance.

Moreover, since the high-speed reverse gear is engaged with the large-diameter gear portion of the first-selection sliding gear used during high-speed forward to perform high-speed reverse gear shift, the number of parts is determined based on the combination of parts. It is possible to reduce the number of cars and simplify the structure, but by adding only the high-speed reverse gear, the main shift reverses 2
It is possible to realize the tiered structure and to minimize the cost of the two-stage reverse structure.

[Brief description of drawings]

FIG. 1 is a side view of a walk-behind management machine.

FIG. 2 is a schematic side view of the same as above showing a state in which a handle is inverted.

FIG. 3 is a side sectional view of a transmission.

FIG. 4 is a developed sectional view of the same.

5 (A), (B) and (C) are table diagrams showing output rotation speeds of various transmissions, and FIG. 5 (D) is a table chart showing output rotation speeds suitable for various works.

[Explanation of symbols]

 1 Pedestrian Management Machine 4 Transmission 9 Main Transmission Shaft 10 Back Shaft 11 Sub Transmission Shaft 13 Main Transmission Mechanism 14 Sub Transmission Mechanism 16 Sub Transmission Shift Sliding Gear 22 First Selection Sliding Gear 22a Large Diameter Gear 22b Small Diameter Gear 23 Second selection sliding gear 24 High speed forward transmission gear 25 Medium speed forward transmission gear 26 Low speed forward transmission gear 29 Low speed reverse transmission gear 32 High speed reverse transmission gear

Claims (1)

[Claims] 1. A main transmission shaft equipped with a first selection sliding gear and a second selection sliding gear for main transmission, and an auxiliary transmission shaft equipped with a selection sliding gear for auxiliary transmission. A back shaft is disposed above the sub-transmission shaft via a constant mesh gear, and both ends of the sub-transmission shaft are selectively meshed with the large-diameter gear portion of the first selection sliding gear to sub-shift. Distributing a high-speed forward transmission gear that transmits high-speed forward power to the shaft and a pair of medium- and low-speed forward transmission gear that selectively meshes with the second selection sliding gear and transmits medium-speed or low-speed forward power to the auxiliary transmission shaft. On the other hand, in the middle part of the back shaft, a small-speed reverse gear shift gear that selectively meshes with the small-diameter gear part of the first selection sliding gear and transmits low-speed reverse power to the sub-transmission shaft is provided. In a transmission for agricultural machinery, the low space is placed in the space above the auxiliary sliding selection sliding gear. A high-speed reverse gear is arranged in parallel with the high-speed reverse gear, and a high-speed reverse power is applied to the auxiliary transmission shaft based on the selective meshing between the high-speed reverse gear and the large-diameter gear portion of the first selection sliding gear. A transmission for small agricultural machines characterized by transmitting power.