JPS6136021A - Transmission structure of traveling agricultural machine - Google Patents

Abstract

PURPOSE:To prevent the attitude change of a sleeve due to the energizing force of a spring and obtain a good torque limiting function by sufficiently setting the coupling length with the rotary shaft of the sleeve in a transmission structure provided with a torque limiting mechanism utilizing the energizing force of the spring. CONSTITUTION:A lateral rotary shaft 11 is connected to an engine output shaft 1 of a gear transmission structure H, the first rotary shaft 13, second rotary shaft 14, PTO shaft 8, third rotary shaft 16, and final reduction shaft 17 are assembled in parallel with this rotary shaft 11, and the first gear reduction mechanism H1 is provided on individual rotary shafts 13, 14. A transmission sleeve 37 is slidably coupled with the rotary shaft 11 from outside, a rotation transmission member 38 is freely coupled with one side of the rotary shaft 11, and a torque limiting mechanism 40 is inserted between them. A spring 41 applying the thrust energizing force for torque transmission to the said mechanism 40 is provided on the other end of the transmission sleeve 37, and part of the transmission mechanism is allowed to approach near the outer periphery of the sleeve 37.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a power transmission structure of a mobile agricultural machine, such as a walk-behind rice transplanter, which is equipped with a torque limiting mechanism that utilizes the biasing force of a spring as a set torque pressure. Regarding.

[Conventional technology]

One of the conventionally known transmission structures of this type is disclosed in Japanese Utility Model Application Publication No. 56-37688. A transmission sleeve is fitted onto the rotary shaft so as to be movable in thrust and non-rotatable relative to the rotary shaft, and a transmission gear is loosely fitted and supported on one end of the rotary shaft, and the side surface of the transmission gear and one end of the transmission sleeve are Each with a flange provided on the
A concave and convex engaging portion that can be fitted into and disengaged from each other is provided as a torque limiting mechanism, and the other end of the transmission sleeve is pressed and biased toward the transmission gear to provide a torque transmission thrust force to the torque limiting mechanism. A spring that provides biasing force was fitted onto the rotating shaft to form a transmission structure.

[Problems to be Solved by the Invention] Therefore, with the conventional structure in which a coil spring and a spring receiver are provided on the other end of the sleeve, it is not possible to secure the length necessary for transmitting power to the rotating shaft over the entire length of the sleeve. Since the fitting length to the rotating shaft is not sufficient, the posture tends to change when sliding against the biasing force of the spring, and smooth torque limiting operation is hindered by twisting etc. There was a risk that this would happen.

An object of the present invention is to provide a transmission structure that can perform smooth torque limiting operation and make the transmission structure more compact by utilizing modifications made for this purpose.

[Means for solving problems]

The characteristic configuration according to the present invention is that a long automatic sleeve is externally fitted onto the rotating shaft so as to be movable in thrust and non-rotatable relative to each other, and a rotational transmission member is loosely fitted and supported on one end of the rotational shaft, and a side surface of the rotational transmission member is provided. and a flange provided at one end of the transmission sleeve, and a torque limiting mechanism is provided at the other end of the transmission sleeve to press and bias the sleeve toward the rotational transmission member side to transmit torque to the torque limiting mechanism. S2
A spring that provides a biasing force is fitted onto the rotating shaft,
A part of the transmission mechanism is placed close to the outer peripheral surface of the sleeve between the flange and the spring, and its effects are as follows.

[For production]

Since the external fitting length of the tab and the transmission sleeve with respect to the rotating shaft is made as long as possible, even if a posture changing force is applied to the transmission sleeve due to the spring biasing force, the transmission sliding angle with respect to the rotating shaft is small. Smoother torque limiting operation can be performed without causing wrinkles, twisting, etc.

In addition, a large space is formed around the transmission sleeve between the flange of the transmission sleeve and the spring in contact with the other end, corresponding to the length of the sleeve. By arranging it, the transmission mechanism can be arranged in a condensed manner, and the transmission structure can be made compact.

〔Effect of the invention〕

As a result, the frequency of maintenance required for the torque limiting mechanism is reduced, the transmission structure itself can be made more compact, and the tolerance for its arrangement and configuration is increased when it is mounted on a mobile agricultural machine.

〔Example〕

As shown in Figure 3, the output shaft (1) points toward the rear of the aircraft.
The transmission case (3) is attached to the rear of the engine (2) equipped with
) is directly connected to the transmission case (3), and a wheel transmission case part (8A) with the wheels (4) + (4) pivotally supported at the lower end extends downward from the transmission case (3), and is connected to the rear of the transmission case (3). A power transmission case (7) for a working device (7) that pivotally supports a tilling device, which is one of the working devices (6), is attached and fixed to the connecting pitch (5) provided, and a projecting part is attached to the side of the mission case (3). An auxiliary transmission case (9) is installed between the installed PTO shaft (8) and the input shaft of the tilling device (6), thereby forming a PTO transmission structure, and furthermore, The tilling cover α0 is movably supported on the machine body to constitute a walking type tiller.

As shown in Figures 1 and 2, gear transmission (6)
To explain the structure in detail, a horizontal rotating shaft (b) is provided at the front end of the transmission case (3) and is linked to the engine output shaft (1) with a bevel gear, and a horizontal rotating shaft (b) is provided in parallel with the rotating shaft αυ. The first rotation axis □, tax rotation axis C14),
Incorporating the PTO axis (8), the ① rotation axis aO, and the final gear shift axis αη, the 1st rotation axis (to) and the ① rotation axis Q are synchronized mesh types that can also be used as the main clutch and can be switched to two stages, high and low. A first gear transmission mechanism (Hl) is provided.

The PTO shaft (8) is provided with a gear α9 integrally molded with the shaft (8) and a gear (G) fitted so as to be able to rotate integrally therewith, and a large diameter gear having a long boss portion). A two-stage gear eυ, which is loosely fitted and slidable in the axial direction, is spline-fitted to the boss portion of this large-diameter gear (E). In addition, a passive gear is fitted onto the No. 1 rotating shaft (10), and a shaft-integrated gear (A) is provided, and a two-stage gear @ is spline-fitted so as to be slidable in the axial direction. , internal teeth (8
4A) and an 8-stage gear integrally formed with external teeth of two sizes, supported by bearings. Then, the final gear shift shaft (171
In addition to fitting the large diameter (c) and small diameter gear),
A transmission sprocket (to) is fitted to the axle (b).

Based on the above configuration, the two-stage gear (G) fitted on the No. A two-stage gear (
By selective engagement with the large diameter gear (c) fitted on the final shift shaft aη of 2) and the external teeth of the 8th gear, the gears Ql and (to), and (a) and (e) are A forward/reverse transmission mechanism is provided which can switch forward and reverse the power transmitted to the PTO shaft (8) via the occlusal transmission and transmit it to the final transmission shaft a''i).

By the lateral sliding of the second gear spline-fitted to the second rotating shaft σQ, the large-diameter gear of the final transmission shaft αη is
and the internal teeth (84A) of the 8-speed gear (B) are engaged with the 2-speed gear respectively, and the power transmitted from the PTO shaft (8) is transmitted independently from the forward/reverse transmission mechanism (Hl). A third gear transmission mechanism (H3) that can be shifted to two high and low gears is provided.

The above is the first gear transmission mechanism (Hl) and the second gear transmission mechanism (Hl).
4 forward speeds and the 1st gear transmission mechanism (H3)
L) and the forward/reverse transmission mechanism (Hl) work together to form a gear transmission (B) that can be switched to two reverse gears.

A boss portion (28A) of a chain sprocket) is attached to an axle that is pivotally supported at the lower end of the wheel transmission case portion (3A) extending downward and forward of the transmission case (3).
A ball-type clutch mechanism (40) consists of a pair of left and right parts that butt and loosely fit into the chain sprocket boss part (28A) and four parts formed on the axle.
and is configured to be able to transmit the chain driving force from the final shift shaft (171) to the left and right axles (2) separately.

The forward and backward transmission mechanism (Hl) and the #1 gear transmission mechanism (H
The shift fork shafts 6η and (2) for the two-stage gears (2) and (a) in 3) are ball-type check mechanisms (not shown).
are provided, and are configured so that they cannot operate simultaneously.

A long transmission sleeve is fitted onto the rotating shaft (b) so as to be movable in thrust and non-rotatable relative to each other, and a transmission gear, which is one of the rotational transmission members (to), is attached to one end of the rotating shaft (b). A flange (37A) is provided on the side surface of the transmission gear (to) and one end of the transmission sleeve (2).
A plurality of retaining holes (88a) + (8?a) are formed at the same radial position on opposing surfaces between the two, and
The end of the ball-shaped transmission member is internally held in each of the corresponding retaining holes 188a) and (37a), so that power can be transmitted from the transmission gear (to) to the transmission member) to the transmission sleeve (b). This constitutes a torque limiting mechanism (40).

At the other end of the transmission sleeve, a disc spring O is attached to the rotating shaft ( (b) is fitted externally to the transmission member, so that when a torque that resists the biasing force by the disc spring (2) is applied, the transmission member () escapes from the engagement hole (aSa) or (, 97a) and the transmission is transmitted. It is configured to cut off power transmission between the sleeve (b) and the transmission gear (ii).

A state in which a part of the transmission mechanism of the first gear transmission mechanism (Hl) is close to the sleeve (B) in a space formed near the outer peripheral surface of the sleeve (2) between the flange (37A) and the disc spring (2). It is set in.

[Another example]

The torque limiting mechanism may be provided with uneven retaining portions on the side surface of the transmission gear (to) and the flange (37A), respectively, or may be formed into a gear shape.

The spring (c) may be of a coil type.

The embodiments described above may be applied not only to walk-behind tillers, but also to other mobile agricultural machines such as tractors and transport vehicles.

[Brief explanation of the drawing]

The drawings show an embodiment of the power transmission structure for a mobile agricultural machine according to the present invention, and FIG. 1 is a vertical cross-sectional rear view of a transmission case, FIG. 2 is a vertical cross-sectional side view of the mission case, and FIG. 8 is a side view of a walk-behind cultivator. It is. (11)...Rotating shaft, (To)...Transmission sleeve, (37A)...Flange, (To)...
...Rotation transmission member, ■...Torque limiting mechanism, (b)...Spring.

Claims (1)

[Claims] A long automatic sleeve (37) is externally fitted onto the rotating shaft (11) so as to be thrust movable but not relatively rotatable, and a rotational transmission member (38) is loosely fitted and supported on one end side of the rotating shaft (11); A torque limiting mechanism (40) is interposed between the side surface of the rotation transmission member (38) and a flange (37A) provided at one end of the transmission sleeve (37), and the other end of the transmission sleeve (37) a spring () which presses and biases the sleeve (37) toward the rotational transmission member (38) and applies a thrust biasing force for torque transmission to the torque limiting mechanism (40);
41) is fitted onto the rotating shaft (11), and a part of the transmission mechanism is brought close to the outer peripheral surface of the sleeve (37) between the flange (37A) and the spring (41). Transmission structure of agricultural machinery.