RU2104882C1 - Small-size tractor - Google Patents

Abstract

FIELD: transport engineering; all-wheel-drive small- size tractors. SUBSTANCE: small-size tractor has three forward and one reverse speeds. Movement of tractor is provided by engaging constant-mesh gears 23 and 24 and shaft 22 by means of gearshift toothed sleeves 25. Speed range of tractor is distributed in corresponding two speed ranges, main and travelling, by means of speed doubler - cluster gear 15 on first shaft 14 and driven gears 18 on second shaft 17. Ranges and speeds are selected by means of double-sided three-position gearshift toothed sleeves 19 and 25, with disengagement of corresponding driven gears in neutral. Torque from engine 11 is transmitted through first shaft 14 and friction clutch 16 to cluster gear 15 of doubler and to one of driven gears 18 through toothed sleeve 19 shifted into one of operating positions, to second shaft 17 and through one of gears 20, 23 or 21, 24 to shaft 22. Then torque, from gearbox 8 is transmitted by propeller shafts 6 and 7 to unified final drives 5 of front and rear axles, 3 and 4 of tractor, respectively, furnished with wheels 1 of equal type-size. EFFECT: enlarged operating capabilities. 1 dwg

Description

 The invention relates to vehicles, mainly to small-sized tractors such as wheeled universal self-propelled chassis with permanent all-wheel drive.

 A known design of a vehicle equipped with a front-mounted cab and two drive axles of all wheels. The front and rear axles are equipped with final drives and self-locking differentials [1]. The power transmission is made with a single-disk dry clutch, a gearbox connected by a cardan shaft with a two-stage transfer case and directly with the power take-off. The transfer case, in turn, is connected by two cardan shafts to the main gears of the drive axles.

 The disadvantages of this vehicle include the presence of three nodes - a gearbox, a power take-off and a transfer case, which are not functionally combined into one unit with an additional cardan transmission, which, when these units are carried out in separate cases, complicates the design and increases the material consumption of the power transmission. In addition, gear shifting in these boxes is carried out using movable gears, the engagement of which is characterized by end wear and chipping of the tops of the teeth. In this regard, the gearbox is equipped with gear synchronizers, respectively, complicating the design. In addition, the durability of dry friction clutches is insufficient.

 The invention is aimed at eliminating the noted drawbacks, to improve the operational capabilities of a small tractor.

 As a prototype, the technical solution is described in the book [2], which presents the kinematic diagram of the power transmission of the T-125 tractor. The tractor power transmission contains separate components, a dual clutch of dry friction clutch with an independent drive of the power take-off gearbox equipped with a portable clutch, a gearbox with four forward gears, made in contrast to the analogue and gears of constant engagement and equipped with a creeper, a two-speed transfer case a box with a switchable drive (at the request of the driver) of the front drive axle, three cardan gears (to the bridges and power take-off reducer) axles with final drives and differentials, as well as planetary final drives.

 The disadvantages of the design of the prototype, as well as that of the analogue, include the implementation of transmission units in separate housings, which increase the material consumption, a switchable front-wheel drive, which makes it less stable on the road and reduces cross-country ability. The installation of the clutch on the engine increases the axial dimension of the power unit of the vehicle, and the implementation of the clutch - dry type does not provide the required reliability.

 Power transfer of the prototype at a reduced range of traction speeds is carried out through five pairs of gears with the rear wheels and six pairs of gears to the front wheels, which reduces traction efficiency and significantly complicates the design. In addition, the installation of the engine in front of the front som does not provide an equal distribution of the axial load.

 To do this, a small-sized tractor containing a self-propelled chassis with permanent drive on all wheels, the front of which is steered, mounted on the front and rear axles having main gears with self-locking differentials, includes an engine, gearbox and power take-off gear. An engine is mounted between the front and rear axles, which is connected to a gearbox connected by three driveshafts to the axles and a power take-off gear. The gearbox is made with two pairs of gears on all gears of the two ranges of traction and vehicle forward speeds. The gearbox is made with three longitudinal power transmission shafts per stroke and a longitudinal power take-off shaft. On the first shaft of the gearbox, connected with the crankshaft of the engine, there is a block of gears of the doubler of gears, which rotates freely on this shaft and is connected to it by means of a friction multi-plate clutch sequentially mounted behind the block operating in a common oil bath of the gearbox. On the second shaft there is a knot for switching on the doubler of gears and drive gears of gears. On the third shaft there is a switching unit for driven gear gears, and on the fourth shaft, which is located coaxially with the first, there is a switching unit for several independent power take-offs.

 In contrast to the analogue, the compact tractor is made with a common transmission unit with gears of constant meshing and a wet type clutch. In contrast to the prototype, the vehicle's traction efficiency is increased by reducing the number of gear engagement pairs, a permanent drive on all traction axes is provided, reliability is improved and the design is simplified.

 Small-sized tractor (drawing) is made with permanent drive on all wheels 1, 2, front 1 of which are steered. Wheels 1, 2 are mounted above the front 3 and rear 4 axles, equipped with main gears with self-locking differentials 5, connected by cardan shafts 6, 7 with the gearbox 8. A cab 10 or safety cage is mounted above the front of the frame 9, between the front 3 and rear 4 bridges - an engine 11, block-connected with a gearbox 8, in the rear of the frame 9 - a power take-off reducer 12 connected to the gearbox 8 with a cardan shaft 13. The gearbox 8 is made with four longitudinal shafts, on the first of which 14 is a block of leads gears 15 of the gear doubler, freely rotating on the shaft 14 and connected to it by means of a friction multi-plate clutch 16 with disks operating in the common oil bath of the gearbox 8. In this case, the gear block 15 and the clutch 16 are arranged in series on the shaft 14. On the second shaft 17, the driven gears 18 of the doubler of the gear rotate freely, which are connected to the shaft 17 by a flange gear ring 19. The drive gears 20, 21 of three forward gears and one reverse gear are rigidly fixed. On the output third shaft 22, the driven gears 23 of the forward and 24 reverse gears are freely mounted, connected to the shaft by means of two flange gear rings 25, unified with the first 19. On the console of the fourth shaft 26, coaxially located with the first 14, the power take-off 27 and 13.

 The small tractor is driven in three forward gears and one reverse gear by connecting the driven gears 23 and 24 to the shaft 22 with flange gears 25. Using the gear doubler, the drive block gear 15 on the first shaft 14 and the driven gears 18 on the second shaft 17, the speed range of the tractor is distributed in the respective two transmission ranges - main and transport. Shifting of ranges and gears is carried out using gear rings 19 and 25, which are made of double-sided three-position ones - with the corresponding driven gears disconnected in the neutral position. Torque from the engine 11 through the first shaft 14 and the friction clutch 16 is transmitted to the block gear 15 of the doubler of gears and one of the driven gears 18, through a gear ring 19 included in one or another working position, to the second shaft 17, through one of the gears 20, 23 or 21, 24 to the shaft 22. Next, the torque from the gearbox 8 is transmitted by the driveshafts 6 and 7 to the unified main gears 5 of the front 3 and rear 4 axles of the tractor, equipped with wheels 1 of equal size.

 Power take-off is carried out independently, both during driving and when the tractor is parked. The tractor design provides for power take-off from the fourth shaft 26 of the gearbox 8 with two independent channels 28 and 13. The power take-off unit 27 is turned on when the engine is stopped.

 The technical and economic effect is ensured by increasing the operational capabilities of a small tractor.

Claims (1)

A small tractor containing a self-propelled chassis with permanent drive on all wheels, the front of which is steered, mounted on the front and rear seats, with main gears with self-locking differentials, including an engine, a gearbox with four longitudinal shafts and a power take-off gear, the first the gearbox shaft, on which the gear block is located, is kinematically connected to the engine, the third drive shaft of the driven gears is connected by cardan shafts to the bridges, the fourth drive shaft power take-off, which is located coaxially with the first one, is connected by a cardan shaft to a power take-off gear, characterized in that an engine is mounted between the front and rear axles, the crankshaft of which is connected to the first gearbox shaft with a freely rotating gear doubler gear unit and made with the possibility of connection to the shaft of a friction multi-plate clutch sequentially mounted behind the gear block with a common oil bath of the gearbox, while the inclusion unit is located on the second gearbox shaft Nia doubler gear and drive pinion gear, and the third shaft assembly incorporating the driven gears constant mesh gears forward and reverse, and the fourth shaft
unit for switching on independent power take-offs.