JP2609904B2 - Transmission equipment for agricultural tractors - Google Patents

Description

The present invention relates to a transmission in an agricultural tractor, particularly to a traveling transmission.

(B) Prior art Conventionally, as a transmission device in an agricultural tractor, which can be switched to forward and backward and when shifting in multiple stages in a forward transmission state, it is already known that a forward / reverse speed change gear is provided separately from a traveling speed change shaft. Are known.

(C) Problems to be Solved by the Invention Since the transmission in the known agricultural tractor is provided with the forward / reverse transmission gear separately from the traveling transmission shaft, the transmission case becomes large and the number of shafts increases. There were problems such as an increase in the number of assembly steps.

(D) Means for Solving the Problems The present invention arranges a distribution shaft to which the power of the engine is transmitted in the middle part of the transmission case, supports the power take-out shaft on one side, and runs on the other side. A transmission shaft is supported, and a high-speed gear, a medium-speed gear, and a low-speed gear for power take-out are provided on the distribution shaft, and a reverse tractor is meshed with the medium-speed gear. A sleeve is loosely fitted, a forward / reverse transmission gear is slidably mounted on the sleeve, and the forward / reverse transmission gear is selectively meshed with the high-speed gear or the reverse gear. The aforementioned problems were solved by reducing the number of shafts by equipping the main transmission gear.

(E) Operation The power of the engine is transmitted to the distribution shaft disposed in the middle part of the transmission case via the clutch housing and the transmission device in the intermediate case, and the power is transmitted to one of the power take-off shaft and the other traveling speed change shaft. The power take-off shaft drives the PTO shaft through the PTO reduction mechanism.

When the forward / reverse transmission gear of the sleeve loosely fitted to the traveling transmission shaft meshes with the high-speed gear of the distribution shaft, the sleeve rotates in the driving direction, and the forward / reverse transmission gear meshes with the reverse gear. The sleeve rotates in reverse drive traverse.

In addition, the main transmission gear is rotated integrally with the sleeve while the sleeve is rotated in the forward drive direction, or the main transmission gear is meshed with a gear driven by the sleeve to perform the main traveling speed.

(F) Embodiment An embodiment of the present invention will be described with reference to the drawings. A flywheel 2 of an engine 1 drives a main shaft 5 via a main clutch 4 in a clutch housing 3, and a rear end of the flywheel 2 enters a rear gear case 6. The gear 7 fixed to the gear 7 and the gear 8 meshed with the lower surface of the gear 7
The holder 9 is supported by a bearing 10 and is screwed to the front plate 12 of the intermediate case 11.

The mission case 13 is a spacer case 14 and a main case
The clutch housing 3 and the clutch housing 3 are connected to each other by bolts. The front end of the cylindrical shaft 17 housed in the intermediate case 11 is spline-fitted to the gear 8, and the rear end is the spacer. A spline joint 19 is connected to a front end of a distribution shaft 18 composed of a cylindrical shaft rotatably supported by the case 14, and a high-speed gear 20, a medium-speed gear 21, and a low-speed gear 22 are sequentially connected to the distribution shaft 18 from the front. It is protruding.

Further, a power take-out shaft 23 supported above the distribution shaft 18 is provided with a gear 24
And a gear 25 that meshes with the low speed gear 22 are rotatably fixed,
The sliding gear 26 fitted to the intermediate spline is the gear 24 or 25.
Disengages with the two splines on the outer periphery of the boss and also engages with the medium speed gear 21 to change gears in three steps.
The rear end drives the PTO shaft 30 via the reduction gears 27 and 28.

Further, both ends of the traveling transmission shaft 31 are rotatably supported by bearings in the spacer case 14 below the distribution shaft 18, and a spacer 32 is provided at a portion extending from the front portion to the middle portion of the traveling transmission shaft 31. A sleep 35 is rotatably fitted through a pair of front and rear needle bearings 33, 33 with an interval maintained, and a forward / reverse transmission gear 36 is provided at the front of a spline engraved on the outer periphery of the sleeve 35. The gear 37, which is fitted only to slide forward and backward, and is spline-fitted to the rear, is stopped at the front and rear by a retaining ring, and the same spline as the spline of the sleeve 31 is engraved on the outer periphery of the rear part of the sleeve 35 of the traveling transmission shaft 31. The first main transmission gear 38 is fitted and fitted.

Further, a counter shaft 40 rotatably supported on the side between the distribution shaft 18 and the traveling speed change shaft 31 is provided with a gear 41 meshed with the gear 37 and a gear 42 having a smaller diameter than the gear 41 at the rear thereof. The front portion rotatably supports a reverse gear 43 always meshed with the middle speed gear 21.
When the sleeve 35 is slid forward and meshes with the high-speed gear 20, the sleeve 35 rotates forward (forward direction), and when slid backward and meshes with the reverse gear 43, the sleeve 35 reversely rotates (reverse direction) to move forward and backward. With the transmission gear 36 engaged with the high-speed gear 20, the first main transmission gear 38 is slid forward and engaged with the sprue of the sleeve 35 to rotate integrally, or is slid backward to reduce the diameter of the small-diameter gear 42. A two-stage shift can be performed by engaging with the gears.

The rear traveling transmission shaft 44 rotatably supports the front portion in a recessed portion at the rear end of the traveling transmission shaft 31 via a needle bearing,
The rear part is supported by the partition wall 45 of the main case 15 via a bearing, the second main transmission gear 46 is spline-fitted only in the front part to allow sliding, and the small gear 47 and a large gear 47 are provided in the middle part. gear
Sub-transmission drive gear 50 consisting of 48 and inner diameter gear 49 inside thereof
Is rotatably supported, and a switching gear 51 is slidingly spline-fitted to the rear portion, and a shaft having a reduction gear 53 and a small gear 54 is attached to the side portion by a boulder 52 screwed to the inner surface of the main case 15. Supports 55.

A pinion shaft 58 whose rear end pinion is screwed to a ring gear 57 of a rear wheel differential 56 is rotatably supported by inserting a front portion into the rear end of the cylindrical shaft 17 and interposing a needle bearing. The rear part is supported by the partition wall 45 via a bearing, and the intermediate gear 60 rotatably loosely fitted to the front part of the pinion shaft 58 is fixed to the gear 59 spline-fitted to the rear part of the traveling speed-change shaft 31. It consists of a meshing large gear 60a and a rear small gear 60b, which is only rotatable, and an auxiliary transmission gear 61 consisting of large and small gears is spline-fitted in the rear of it so that it can slide back and forth. It is.

Since the drive shaft 63 of the front wheel 62 is connected to the front end of the pinion shaft 58 by the spline joint 64, both shafts 58 and 63 rotate integrally, and the gear 65 attached to the front end of the pinion shaft 58 is passively driven through the intermediate gear 66. The passive gear 67 is transmitted to a gear 67, and the passive gear 67 is fixed to a cylindrical body which is integral with a differential case of a differential gear 68 for increasing front wheels.
The front operating shaft is linked to a front wheel differential device 70, and its power is transmitted to the front wheels 62, 6 via left and right final reduction mechanisms 71.
2, the front wheel drive switching device 72 moves the hub 73 forward to release the ball 74 connecting the cylinder part and the operating shaft to the two-wheel drive state, and the four-wheel drive connecting the both with the ball 74. When the state is switched to the state in which the four-wheel drive state is shifted to the rear two-drive position and the desk brake is operated in this two-wheel drive state to stop the rear differential shaft, the front wheels are driven at double speed.

Further, the left and right differential shafts of the rear wheel differential device 56 drive the rear wheels 76 via the rear wheel final reduction gear mechanism 75. 77 is the main transmission lever, 78
Is a driver's seat, and 79 is a step extending from the upper surface of the intermediate case to the left and right.

Thus, when the first main transmission gear 38 is slid forward and meshed with the outer peripheral spline of the sleeve 35 while the forward-reverse transmission gear 36 is meshed with the high-speed gear 20, the sleeve 35 and the traveling transmission shaft 31 are connected. When the gears rotate integrally with each other and are slid rearward to mesh with the gears 42, the traveling transmission shaft 31 causes the sleeve 35 to rotate the gears 37 and 41.
And the gear ratio of the gear 42 and the first main transmission gear 38 are used to drive the rotation with a reduction ratio of 48/56 × 54/51.
At that time, the counter shaft 40 serves as both the shafts of the gears 41 and 42 involved in deceleration and the support of the reverse gear 43, so that the configuration can be simplified, and the PTO drive by the gears 41 and 42 is possible. Since a speed ratio specific to the traveling speed can be obtained separately from the medium speed gear 21 and the low speed gear 22 of the system, and the first main speed gear 38 is prevented from meshing with the speed change gear of the distribution shaft 18. As a result, the gear train is shortened, whereby the intermediate case is lengthened and the flat step surface is widened to improve the driving comfort.

In addition, the second main transmission gear 46 slides forward to drive the traveling transmission shaft.
When meshed with the rear end spline 31 a of the rear transmission gear 31, the rear traveling transmission shaft 44 rotates integrally with the traveling transmission shaft 31 and the second main transmission gear 46
When the gear is slid backward to mesh with the small gear 60b of the intermediate gear 60, a further one-stage main speed change is performed.
With the 51 engaged with the inner diameter teeth 49 of the auxiliary transmission drive gear 50, the auxiliary transmission gear 61 is connected to the small gear 47 or the large gear 48 of the auxiliary transmission drive gear 50.
By selecting and meshing any one of the above, two-stage sub-shifting can be performed, and when the switching gear 51 is meshed with the reduction gear 53, the speed is reduced.

(G) Effects of the Invention Since the present invention is configured as described above,
The two shafts can be formed as one by loosely fitting the sleeve 35 with the mounted 36 on the shaft supporting the main transmission gear, and there is no need to separately support two in a narrow transmission case as in the conventional case. A traveling speed change can be performed separately from the speed change of the take-out shaft 23, and the assembly can be easily performed.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention. FIG. 1 is an exploded sectional view of a transmission, FIG. 2 is a transverse sectional view of the same, FIG. 3 is a transmission system diagram, and FIG. It is a side view which shows. 3 …… Clutch housing, 11 …… Intermediate case, 17 ……
Cylindrical shaft, 18 Distributing shaft, 23 Power take-off shaft, 31 Running speed change shaft, 35 Sleeve, 36 Forward / reverse speed change gear, 38
First main transmission gear, 41, 42… gear, 43… reverse gear, 44
...... Rear traveling speed change shaft, 46 ...... Second main speed change gear, 61 ...... Sub speed change gear

Claims (1)

(57) [Claims] Claims: 1. The power of the engine 1 is transmitted to a rear mission case 13, a distribution shaft 18 is arranged at an intermediate portion of the mission case 13, and a power take-off shaft 23 is supported on one side thereof. On the other side, a traveling transmission shaft 31 is supported, and the distribution shaft
18, a high speed gear 20 for power extraction, a medium speed gear 21 and a low speed gear
In the agricultural tractor in which 22 is provided and the reverse gear 43 is meshed with the medium speed gear 21, a sleeve 35 is loosely fitted to the outer periphery of the front portion of the traveling transmission shaft 31, and a forward / reverse transmission gear 36 is slid on the sleeve 35. Characterized in that the forward / reverse speed change gear 36 is configured to selectively mesh with the high speed gear 20 or the reverse speed gear 43, and the traveling speed change shaft 31 is equipped with a main speed change gear. Transmission device for agricultural tractors.