JPH073078Y2 - Mobile agricultural machine transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a transmission that can be applied to a mobile agricultural machine such as an agricultural tractor, and more specifically, to a transmission shaft that can be assembled from an open hole in a rear wall of a transmission case, and The present invention relates to a transmission having a shift rail that guides a fork engaging with a transmission gear on a transmission shaft.

[Prior art]

In a transmission case equipped in a conventional agricultural tractor, a counter shaft 16 and a PTO shaft 25 driven via the counter shaft 16 are provided behind the case 4 as illustrated in FIGS. The coaxial sleeves 36 and 37 are selectively slid on the idle gear on the PTO shaft 25 that is supported and driven by the transmission gear on the counter shaft 16, so that the PTO shaft 25 reaches a predetermined rotation speed. There is provided a speed change device.

The front ends of the counter shaft 16 and the PTO shaft 25 are supported by the front partition wall 4b in the case 4, but the rear ends thereof are supported by a lid 40 detachably provided on the case rear wall 4a. It is said.

Also, a fork 43 that engages with the sleeves 36, 37 on the PTO shaft 25.
The shift rail 41 for guiding (or 44) also has a structure in which the front end is supported by the partition wall 4b in the case and the rear end is fixedly supported by the lid 40 closing the opening hole 39.

[Problems to be solved by the invention]

By the way, in the above-described conventional structure, when the lid is disassembled, it is necessary to remove the bolts for fixing the shift rail, and
At the time of assembly, the rear end of the shift rail without the lid attached is not positioned, so there is a problem that the engagement / disengagement state of the transmission gear on the PTO shaft with the fork cannot be visually confirmed. When the lid is removed, the rear end of the shift rail is no longer supported, and the speed change gear positioned by the forks and the PTO shaft that supports it are pulled out, so check and confirm the power transmission gear and speed change gear. However, there is a problem in that it is extremely difficult to assemble.

Therefore, the present invention was devised to solve the problem in view of the above-mentioned conventional circumstances.
The purpose of the present invention is to provide a transmission device for a mobile agricultural machine that is easily assembled and disassembled by positioning it on the case side.

[Means for solving problems]

According to the present invention, which achieves the above object, a rear end of a counter shaft, a driven shaft, and a shift rail is pivotally supported by a lid for closing an opening hole in a rear wall of a mission case, and the counter shaft and the driven shaft are supported. A front end of the shift rail is pivotally supported by a wall facing the rear wall, the counter shaft is driven by a transmission shaft, and the driven shaft is driven by a plurality of driven gears meshing with a plurality of power transmission gears mounted on the counter shaft. A plurality of sleeves with hubs for loosely fitting the gears and transmitting the rotation of the driven gears to the driven shafts themselves were mounted, and forks engaging with the respective sleeves were slidably fitted on the shift rails. In a transmission device for a mobile agricultural machine, the rear end of the shift rail is positioned by a positioning bolt protruding from the mission case in a direction intersecting with the shift rail. Is shall.

[Action]

Therefore, when the counter shaft 16, the PTO shaft 25 and the shift rail 41 are assembled in the case 4 from the rear side, the PTO shaft 25 and the bearings 19a are assembled outside, and the counter shaft 16 is excluded from the rear bearing 16a. And assemble it outside. Shift rail 4
Keep the forks 43 and 44 attached to 1. First,
Assemble the counter shaft 16 in the assembled state into the case 4, then assemble the PTO shaft 25 in the assembled state and shift rail 41.
Put together the assembly that puts the front end of the into the hole of the partition wall 4b,
The rear of the shift rail 41 is positioned by the positioning bolt 50.

In this state, if you press the PTO shaft 25 and selectively move the inner arm 47 or 49 with each operation lever 51, the fork will move.
43 or 44 can slide in the direction of the arrow around the neutral N position. At this time, the meshing state of the sleeve 36 with the gears 19 and 31 or the meshing state of the sleeve 37 with the gears 32 and 33 is determined by the gear arrangement on the counter shaft 16 from the rear to the front of the small diameter gear 29, the middle. Since the radial gear 27 and the large diameter gear 26 are arranged in this order, the open hole 39 before the lid 40 is not attached
It can be visually confirmed from.

Then, press the bearing 16a into the rear end of the counter shaft 16 and
By fixing the to the case rear wall 4a with the mounting bolt 40a,
The counter shaft 16, the PTO shaft 25, and the rear end side of the shift rail 41 can be supported by the lid 40.

〔Example〕

Hereinafter, the drawings showing the present invention as an embodiment will be described.

First, explaining the power transmission system diagram of the agricultural tractor shown in FIG. 4, the engine 1 mounted in front of the machine is
A transmission shaft 3 passing through the main clutch 2 is interlocked with a transmission mechanism in a transmission case 4 (hereinafter referred to as a case).

A diff pinion shaft 5 is disposed in front of the case 4, and a pair of left and right rear wheels 6 is driven by a planetary gear type differential device 10 driven by the diff pinion shaft 5.

Further, the transmission gear 7 fixed to the differential pinion shaft 5 is
A gear 13 fixed to a front wheel drive shaft 12 mounted below the case 4 is driven via a transmission gear 11 provided on the intermediate shaft 9 so as to freely rotate. This front wheel drive shaft 12 extends forward and has a planetary gear type differential.
By driving 15 a pair of left and right front wheels 14 are driven.

A drive gear 19 for driving a gear 17 of a counter shaft 16 provided in the rear of the case 4 is fixed to the rear end of the transmission shaft 3,
A main transmission shaft 20 provided above the counter shaft 16 extends forward and is connected to a concentric auxiliary transmission shaft 21, and is provided on a transmission gear 22 provided on the auxiliary transmission shaft 21 and the differential pinion shaft 5. The differential pinion shaft 5 is selectively meshed with the transmission gear 23 so that the rotation direction of the differential pinion shaft 5 is switched between the forward and reverse directions, and the differential pinion shaft 5 is driven at a predetermined rotational speed.

Further, as shown in FIG. 1, behind the case 4, there is a PT which is located below the counter shaft 16 and which is concentric with the transmission shaft 3.
An O shaft 25 is provided, and transmission gears 31, 32, 33 meshing with a large diameter gear 26, a relay gear 27, and a small diameter gear 29 fixed to the counter shaft 16 are freely rotatable on the PTO shaft 25. Is provided. Between the transmission gears 19 and 31, and the transmission gears 32 and 33.
Hubs 34 and 35 for spline fitting are fixed between and, and sleeves 36 and 37 that mesh with clutch gears provided on the outer circumference are provided on the outer circumferences of the hubs 34 and 35 so that they can slide only. ing.

An opening hole 39 is formed in the rear wall 4a of the case 4, and the opening hole 39 is closed by a detachable lid 40 by a plurality of mounting bolts 40a. A bearing 16a for supporting the rear end and a bearing 25a for supporting the rear intermediate portion of the PTO shaft 25 are respectively supported, and the front ends of the counter shaft 16 and the PTO shaft 25 are respectively connected to the front partition wall 4 of the case 4.
The bearing 16b supported by b and the bearing 19a supported by the center of the transmission gear 19 supported by the bearing 3a are supported by the front partition wall 4b.

As shown in FIGS. 2 to 3, in the grooves 36a, 37a provided in the sleeves 36, 37, a neutral N position on the shift rail 41 provided in parallel with the axis of the PTO shaft 25, and a neutral N position thereof are shown. The front side of the front fork 43 and the front side of the rear fork 44, which are slidably moved over the forward and rearward (arrow direction) shift positions centered around, are engaged.

In the grooves 43a and 44a provided above these forks 43 and 44,
The front and rear inner arms 47 and 49, which swing around the front and rear fulcrum shafts 46 provided at positions penetrating the case 4 in the direction orthogonal to the axis of the PTO shaft 25, are fitted into the respective front and rear ends.
Each of the fulcrum shafts 46 has a gearshift lever 51 fixed thereto.
It is rotated by operating in the front-back direction.

A front side of the shift rail 41 is supported by the front side partition wall 4b, but a rear side of the shift rail 41 penetrates the case 4 in the same direction as the axis of the fulcrum shaft 46 and is screwed and fixed to the case 4. Positioned by That is, the rear of the shift rail 41 has a hole 41a formed in the rear of the shift rail 41.
The front end 50a of the positioning bolt 50 is fitted into the rear side of the case 4 to position the rear side of the case 4, but the rear end of the shift rail 41 protruding outside the surface of the rear wall 4a of the case 4 is provided inside the lid 40. Supported by the support hole 52.

As shown in FIG. 2, a collar for restricting the movement of the front fork 43 is provided behind the front fork 43 of the shift rail 41.
53 is fixed by a pin, and each fork 43 is provided with a positioning ball 55 and a spring 56 which are fitted into each stop hole 54 formed in the shift rail 41.

Next, FIGS. 5 to 7 will be described. A hitch guide 60 mounted by a mounting bolt is provided on the rear outer bottom surface of the transmission case 4. The hitch guide 60 is formed in a box shape from an upper plate 61 extending horizontally rearward, a lower plate 62, and left and right side plates 63 fixing these left and right, and is formed between the upper plate 61 and the lower plate 62. The base end side of the swing drawbar 65 is inserted into the space and is connected by the fulcrum pin 64.On the rearward extension side of the swing drawbar 65, the drawbar pin 67 is fixed by fixing the clevis 66 with a bolt. The drawbar pin 67 has a hitch portion 70, and the drawbar pin 67 is prevented from falling off by a linch pin 69.

In addition, the swing drawbar is located behind the hitch guide 60.
Three holes 71a into which pins 71 for positioning 65 at the center C position and the right R position or the left L position are inserted are provided, respectively.

When the proximal end side of the swing drawbar 65 is inserted into the hitch guide 60, the swing drawbar 65 contacts the back surface of the upper plate 61 on the fulcrum pin side and the upper surface of the lower plate 62 on the pin 71 side because of the center of gravity on the rear side. Therefore, the vibration of the airframe accompanying the vibration of the engine causes a contact noise.

Therefore, in the vicinity of the fulcrum pin 64 of the swing drawbar 65,
Holding bolt 72 and lock nut 73 that are screwed onto the upper plate 61
By the pressing by the regulation mechanism 75, the swing drawbar 65 is allowed to swing to the left and right around the fulcrum pin 64, and the upper surface of the swing drawbar 65 comes into contact with the back surface of the upper plate 61 to generate noise. It has become possible to prevent.

[Effect of device]

As described above, according to the present invention, the rear ends of the counter shaft and the driven shaft are rotatably supported by using the lid that closes the opening hole of the rear wall of the transmission case, but are engaged with the sleeve with the hub on the driven shaft. Since the rear end of the shift rail that slides and guides the fork is positioned by the positioning bolt attached to the mute case, the meshed state of the fork and the sleeve with hub can be visually observed by utilizing the open hole in the open state.

In addition, even when the lid is removed for disassembly and inspection, the shift rail is positioned and supported by the positioning bolts on the case regardless of the lid removal, so the transmission gears are fixed in position by the forks and remain in the case. Since it remains, it is possible to easily inspect and confirm the power transmission gear and the transmission gear.

[Brief description of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a vertical sectional side view of a transmission case, Fig. 2 is a vertical sectional side view of a shift rail, and Fig. 3 is a positioning bolt and a fulcrum shaft of the transmission case. Fig. 4 is a vertical cross-sectional side view of the position connecting the points, Fig. 4 is a power transmission system diagram of the agricultural tractor, Fig. 5 is an overall side view of the agricultural tractor, and Fig. 6 is a side view of the swing drawbar shown with a part broken away. , FIG. 7 is a plan view of FIG. 4 …… Transmission case, 4a …… Rear wall, 16 ……
Counter shaft, 25 …… PTO shaft, 36 …… Sleeve, 37 …… Sleeve, 39 …… Open hole, 40 …… Lid, 41 …… Shift rail, 43 …… Fork, 44 …… Fork, 47 …… Inner Arm, 49 ... Inner arm, 50 ... Positioning bolt, 59 ... Support hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliographic references Sho 62-44169 (JP, U) Japanese Patent Sho 62-39303 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A counter shaft, a driven shaft, and a shift rail are supported at their rear ends by a lid for closing an opening hole in a rear wall of a mission case, and the counter shaft, the driven shaft, and a front end of the shift rail. Is rotatably supported by a wall facing the rear wall, the counter shaft is driven by a transmission shaft, and a plurality of driven gears that mesh with a plurality of power transmission gears mounted on the counter shaft are loosely fitted to the driven shaft. In addition, a plurality of hubbed sleeves for transmitting the rotation of the driven gear to the driven shaft itself are mounted, and further, a fork engaging with the sleeves is slidably fitted to the shift rail, so that the shift of a mobile agricultural machine is changed. In the device, the rear end of the shift rail is positioned by a positioning bolt protruding from the mission case in a direction intersecting with the shift rail. Apparatus.