JPS6331824A - Front wheel driving device for agricultural tractor - Google Patents

Abstract

PURPOSE:To increase the ground clearance, by forming a ring gear in a front wheel differential mechanism with a spur gear and driving said gear by an input from a rear transmission through a counter shaft while simultaneously locating the drive shaft of the front wheel differential mechanism higher than the axis of a counter shaft. CONSTITUTION:A ring gear 36 in a front wheel differential mechanism is formed by a spur gear. A counter shaft 27 is supported laterally between a drive pinion 19 comprising a bevel gear being rotated by an input from a rear transmission and the ring gear 36 located in front of said pinion 19. A bevel gear 28 gearing with the drive pinion 19 is fixed at one end of the counter shaft 27 while a spur gear 29 gearing with the ring gear 36 is fixed to the other end. Furthermore, respective drive shafts 48, 49 extending to the right and left from the front wheel differential mechanism are set higher by H(approximately same with the difference of diameters between said gears 29, 36) than the axes of the drive pinion 19 and the counter shaft 27. Consequently, the ground clearance of the front drive section can be increased by H.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a front wheel drive device for a four-wheel drive type agricultural tractor.

(b) Prior Art Conventionally, as a device for securing the ground clearance of the machine body of a four-wheel drive agricultural tractor, a hypoid gear is used in the front wheel drive section, and a spur gear is attached to the front end of the input shaft from the rear, and a spur gear is attached to the front end of the input shaft from the rear. A front-rear pinion shaft having a bevel gear at the front end is provided in the front part, the bevel gear at the front end of the pinion shaft meshes with a ring gear consisting of a bevel gear of a differential mechanism, and the spur gear attached to the rear end engages with the input gear. Those in which the upper surface of the spur gear of the shaft meshes are already known.

(c) Problems to be solved by the invention Among the above-mentioned known devices, the strength of the former decreases unless the processing and assembly precision is improved, and the safety factor needs to be increased, which makes the device larger. However, it was not possible to increase the machine height considering the cost involved.

In addition, although the latter allows the differential mechanism to be made higher than the input shaft, the pinion shaft protrudes further forward than the input shaft, resulting in a longer wheelbase and a larger turning radius of the aircraft, which creates another problem. At the same time, unless a spiral bevel gear, which requires a high level of machining accuracy, is used, a compact structure cannot be achieved, and if this spiral bevel gear is used, ground clearance must be sacrificed.

(d) Means for solving the problem The present invention comprises a ring gear of a front wheel differential mechanism with a spur gear,
A horizontal counter shaft is supported between a drive pinion consisting of a bevel gear that rotates with input from the rear transmission and the ring gear located in front of the drive pinion, and meshes with the drive pinion at one end of this counter shaft. Install the bevel gear,
A spur gear that meshes with the ring gear is attached to the other end, and the drive shaft extending left and right from the front wheel differential mechanism is made higher than the axis of the drive pinion and countershaft, thereby minimizing the length of the wheel base. The above-mentioned problem was solved by increasing the height of the front wheel drive section from the ground and avoiding an increase in cost.

(e) Operation Power from the rear transmission is transmitted to the horizontal countershaft by the front-rear drive pinion via the bevel gear, and the spur gear attached to the end of the countershaft is transmitted from the differential case to the horizontal (countershaft) In order to rotate the drive shaft that protrudes parallel to the shaft, a ring gear consisting of a spur gear fixed to the differential case is rotated.

Since the center of the differential case, that is, the axis of the drive shaft is higher than the axis of the countershaft and drive pinion, the lower part of the two gears attached to the countershaft and the lower part of the ring gear are approximately equal. As a result, the height of the front wheel drive unit from the ground can be increased.

(F) Embodiment One embodiment of the present invention will be explained with reference to the drawings.L is a front bracket attached to the engine, and a rear holder 3 attached to it with a port 211 has a bush 4.
A carrier 6 is rotatably supported via an O-ring 5, and the front part of the carrier 6 is inserted into a hole at the rear of the center case 7, and the midway part is screwed onto the center case 7 using a port 8 and a fist. , the support shaft 9 is positioned at the front part of the center case 7 with a knock pin 10 and fixed with a port ll@-.

The support shaft 9 is rotatably supported by a front holder 14 screwed onto the front bracket 1 via a bushing 12 and an O-ring 13 with a pin 15.15, and a spacer 18 is attached to the rear of the front holder 14. By interposing the nut 1B into the threaded portion 17 at the front part, the positioning is performed while minimizing the gap in the front-rear direction.

The rear part of the carrier 6 is driven by a transmission shaft in the longitudinal direction from the rear missi and supports a drive pinion 18 consisting of a bevel gear via bearings 20.21, and spacers 22.21. The position is fixed by a nut 24 with a stop washer 23 interposed therebetween, and oil leakage is prevented by an O-ring 25 and an oil seal 2B.

Further, the drive pinion 1e meshes with a 6R gear 28 spline-fitted to one end of a counter shaft 27 perpendicular to the horizontal direction, a spur gear 29 spline-fitted to the other end, and a spacer 30 on the bevel gear 2. The spacing is specified, and the outer and outer sides are positioned by left and right bearings 31, 32 that support the counter shaft 27 on the carrier 6, and these bearings 31, 32 are received and fixed by retaining rings 33. A seal cap 34 press-fitted on the outside of 32 prevents oil leakage.

The differential mechanism includes a differential case 37 rotatably supported by the carrier 6 by bearings 38 and 39 received by a spacer 40 and a retaining ring 41, and a port 35 screwed onto the outer periphery of one side of the differential case 37. A ring gear 38 made of a spur gear that meshes with the spur gear 28, a small differential gear 42.42 rotatably supported on a shaft 44 fixed through the differential case 37, and these small differential gears 42.42.
The drive shaft 48.4 meshes with the drive shaft and transmits power to the left and right front wheels.
The shaft 44 is fixed to the differential case 37 with a fixing pin 47.

As shown in FIG. 1, the axis of the drive shaft 48.49 is H (approximately the radius of both gears 29.38) from the axis of the drive pinion 19 and the counter shaft 27, which is at the same height. As a result, the lower ends of the spur gear 29 and the ring gear 38 are at approximately the same height, and the lower surfaces of the center case 7 and the carrier 6 are approximately the same plane, so that the front wheel drive section is higher than the ground. As shown in Fig. 3, the height can be increased by H compared to the conventional one.

Further, as shown in FIGS. 1 and 2, the outer periphery of the spur gear 29 protrudes rearward from the small diameter portion of the front end of the drive pinion 18, and the ring gear 3B meshes with the spur gear 28 obliquely forward and upward. This allows the space in the front and rear directions to be used redundantly at two locations, and the drive pinion 1
Although the counter shaft 27 is interposed between the wheel base 8 and the differential mechanism, the wheel base can be made as short as possible.

50 is the front wheel, 5! is a kingpin case, and 52 is a kingpin shaft.

In the above-mentioned device, the drive pinion 13 is rotationally driven by the rear transmission via a longitudinal transmission shaft, and the bevel gear 2 meshing with the drive pinion 19 converts the transmission into lateral transmission, and the other end of the counter shaft 27 The spur gear 29 rotates a ring gear 38 formed of a spur gear in the opposite direction, and the differential mechanism performs differential transmission according to the left and right loads to the drive shafts 48 and 49 that drive the front wheels, as in the conventional system.

(G) Effects of the Invention As mentioned above, the present invention comprises the ring gear 36 of the front wheel differential mechanism made up of a spur gear, and the drive pinion made up of a bevel gear rotated by input from the rear transmission! 9 and the ring gear 36 located at the front thereof, a horizontal counter shaft 2 is provided.
A bevel gear 29 that meshes with the drive pinion 19 is attached to one end of the counter shaft 27, and a spur gear 29 that meshes with the ring gear 3B is attached to the other end of the counter shaft 27, extending left and right from the front wheel differential mechanism. Since the extended drive shaft 48, 49 is made higher than the axes of the drive pinion 19 and counter shaft 27, the height of the front wheel drive section above the ground can be made higher than that of conventional models, and the wheel base is longer. This prevents the turning performance of the aircraft from deteriorating.

In addition, since the bevel gear 28 attached to the counter shaft 27 only needs to change the transmission direction, it does not require a large space, and the large-diameter ring gear 3 can be used to significantly reduce the speed.
Since 6 is a spur gear, it is easy to process and assemble, does not require high precision, can be provided at low cost, and can be constructed compactly.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which FIG. 1 is a longitudinal sectional side view of the front wheel drive section, FIG. 2 is a longitudinal sectional plan view of the same, FIG. 3 is a sectional view of the right side of the same, and FIG. It is a side view compared with a conventional one. 6...Carrier, 7...Center case, 19...Drive pinion, 27...Counter shaft, 28...Bevel gear, 2
9φ - Spur gear, 36 - Fist ring gear, 37 - Differential case, 49 - Fist drive shaft Fig. 1 2゛ Fig. 2

Claims (2)

[Claims] (1) The ring gear 36 of the front wheel differential mechanism is composed of a spur gear, and there is a horizontal gap between the drive pinion 19, which is a bevel gear that rotates with input from the rear transmission, and the ring gear 38 located in front of the drive pinion 19. A counter shaft 27 is supported, a bevel gear 28 that meshes with the drive pinion 19 is attached to one end of the counter shaft 27, and the ring gear 36 is attached to the other end of the counter shaft 27.
The front wheels of an agricultural tractor are equipped with spur gears 29 that mesh with the front wheels, and drive shafts 48 and 45 extending left and right from the front wheel differential mechanism are made higher than the axes of the drive pinion 19 and the counter shaft 27. Drive device. (2) A front wheel drive device for an agricultural tractor according to claim 1, wherein the outer periphery of the spur gear 29 attached to the counter shaft 27 is brought close to and faced the midway portion of the teeth of the drive pinion.