JPS587159Y2 - Gearbox for mobile agricultural machinery - Google Patents

Description

[Detailed description of the invention] The present invention has a first belt transmission device for low-speed rotation transmission and a second belt transmission device for high-speed rotation transmission between the driving shaft and the input shaft of the running system □transmission. This invention relates to a transmission device for a mobile agricultural machine such as a tiller, which is a stand.

In the transmission device of this type of conventional mobile agricultural machine,
A so-called double-tension type transmission device in which a tension clutch is attached to each of the first and second belt transmission devices, and by selectively turning on and off both tension clutches, it is possible to shift between high and low speeds. However, in this case, for example, low-speed rotational transmission is performed under relatively high load operating conditions, such as when low-speed rotational transmission is performed when a relatively large tilling load is applied to a tiller. Because it is often used, during low-speed rotational transmission, the tension applied by the tension clutch alone cannot withstand the applied load, which tends to cause transmission loss such as a belt slip phenomenon.
There were also drawbacks such as the belt being extremely worn.

In view of this point, the present invention has an object to eliminate the above-mentioned drawbacks.

The transmission device for a mobile agricultural machine according to the present invention includes a first belt transmission device for low-speed rotation transmission that keeps the belt under tension at all times between the driving shaft and the input shaft of the traveling system transmission, and a tension clutch that can be turned on and off. A second belt transmission device for high-speed rotational transmission is suspended, and the tension clutch is linked to the axial movement of the movable transmission piece on the input shaft, so that low-speed rotational transmission by the first belt transmission device is connected to the input shaft. A case wall portion of the transmission that supports the input shaft of the mechanism that can be operated to switch between three states: a high-speed rotation transmission state by the second belt transmission, and a non-rotation transmission state by both transmissions, and the two belt transmissions. It is characterized by being interposed between.

That is, according to the present invention, the belt of the first belt transmission device is always kept under tension, and the transmission from the first belt transmission device to the input shaft is performed by the interlocking transmission action of the movable transmission piece. Even though the belt transmission device is used for low-speed rotational transmission under high load conditions, efficient transmission can be ensured without causing belt slip or the like.

Moreover, even though the belt of the first belt transmission device is kept under tension at all times as described above, by moving the movable transmission piece in the axial direction, the low-speed transmission state is achieved only by the first belt transmission device, and the low-speed transmission state is achieved only by the second belt transmission device. Since it is possible to selectively switch between a high-speed transmission state and a state in which transmission by both transmission devices is cut off, it is possible to reliably prevent simultaneous action of both transmission devices, and ensure that the desired speed change operation is carried out normally. I can do it.

Furthermore, since the mechanism for switching the rotational transmission state of each belt transmission device is located between the mission case wall portion and both belt transmission devices, it is difficult to install the mechanism inside the mission case. , there is no need for a complicated operation linking means to operate the mechanism from the outside, it is only necessary to provide a relatively simple operation means for directly operating the mechanism; However, the mechanism is prevented from coming into contact with other objects by using both belt transmission devices themselves or by using a belt cover that is naturally provided to protect both belt transmission devices. Therefore, it is advantageous in that it has a structure that is exposed to the outside and can be easily maintained and inspected, but it is also protected from contact with other objects.

As described above, the present invention has been able to perform the desired speed change reliably and safely, provide efficient transmission in any speed change state, and also improve the durability of the belt.

Hereinafter, an embodiment of the present invention will be explained based on the drawings. Fig. 1 shows an axle 10 protruding from the lower part to which a traveling wheel and a tilling rotary can be selectively mounted, and an input shaft 3 protruding from the upper part. A frame 11 that protrudes forward is fixedly connected to the front of the running system transmission 2 installed, and this frame 1
1 is equipped with an engine 12 having a driving shaft 1 parallel to the input shaft 3, and above the transmission 2,
A traveling type cultivator is shown which is connected with a control handle 13 that extends rearward.

FIGS. 2 to 4 show the main structure of the transmission in this cultivator.

The transmission includes a first belt transmission 5 for low-speed rotation transmission and a second belt transmission T for high-speed rotation transmission suspended between the driving shaft 1 and the input shaft 3, and both 5 and 7. A mechanism 9 for selectively switching to a transmission state is provided to switch between a low speed state, a high speed state, and a neutral state.

The first belt transmission device 5 includes two belts 4 extending between a pulley 14 fixed to the driving shaft 1 and an idler pulley 16 rotatably attached to the input shaft 3 via a bearing 15.
.
The movable transmission piece 8, which engages and disengages from the transmission engagement pin 18 attached to the idler pulley 16, is mounted in a non-rotating state via the spline structure 19 by moving in the axial direction; Thus, by moving the movable transmission piece 8 in the axial direction, the transmission state and the non-transmission state can be switched.

The second belt transmission device 7 wraps the belt 22 around the boots IJ 20 and 21 that are fixedly attached to the shafts 1 and 3, respectively, with a margin, and swings the tension roller 23 to rotate the belt. 22 is provided with a tension clutch 6 which can be switched between a tension transmission state and a relaxed non-transmission state, so that the transmission state and the non-transmission state can be switched by switching the tension clutch 6.

The mechanism 9 includes a shifter 24 that changes the movable transmission piece 8 between an occlusal position, a first occlusal release position inward of the pin 18, and a second occlusion release position outside the pin 18. In addition, an elastic position holding structure 26 using a spring ball is provided between the shifter 24 and its slide guide shaft 25, and a swinging operation for engaging the shifter 24 and changing the position of the shifter 24 is provided. The tool 27 and the rod 28 connected to the tension arm 23 of the tension clutch 6 are interlocked and connected so that the tension clutch 6 is in the engaged state only when the movable transmission piece 8 is in the second disengaged position. , a low-speed rotation transmission state by the first belt transmission device 5, a high-speed rotation transmission state by the second belt transmission device 7, and a non-rotation transmission state of both transmission devices 5 and 7.

Note that 29 is a spring that elastically moves and biases the movable transmission piece 8 in the direction of the first occlusal release position, and the transmission surface 30 that contacts the pin 18 of the movable transmission piece 8 rotates. The movable transmission piece 8 has a pin 1 formed on a surface perpendicular to the direction, and the movable transmission piece 8
When I was ahead of pin 8 and caught up with pin 18,
An inclined surface that prevents simultaneous transmission by the first belt transmission device 5 and the second belt transmission device 7 by pushing the movable transmission piece 8 toward the second disengaged position upon contact with the pin 18. It has 31.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show an embodiment of the transmission device for a mobile agricultural machine according to the present invention, and FIG. 1 is an overall side view of the mobile agricultural machine, FIG. 2 is an enlarged cross-sectional plan view of the main parts, and FIG. 4 is an enlarged longitudinal sectional side view of the main part, and FIG. 4 is an enlarged cross-sectional plan view of the main part. 1... Driving shaft, 2... Driving system mission, 3...
Input shaft, 4... Belt, 5... First belt transmission device, 6... Tension clutch, 7... Second belt transmission device, 8... Movable transmission piece, 9... Mechanism.

Claims (1)

[Scope of utility model registration request] Between the drive shaft 1 and the input shaft 3 of the traveling system transmission 20, there is a first belt transmission device 5 for low-speed rotation transmission that keeps the belt 4 under tension at all times, and a second belt transmission device for high-speed rotation transmission that can be operated with care by a tension clutch 6. The input shaft 3 is connected to the belt transmission device I, and the tension clutch 6 is linked to the movement of the movable transmission piece 8 in the axial direction, so that the first belt transmission device 5 is in a low-speed rotation transmission state. A case wall portion of the transmission 2 that supports the input shaft 3 includes a mechanism 9 that can be operated to switch between a high-speed rotation transmission state by the second belt transmission device 7 and a king state in which both transmission devices 5 and 7 are in a non-rotation transmission state. A transmission device for a mobile agricultural machine, characterized in that it is interposed between the belt transmission devices 5 and 7.