JP2015140110A - transmission case of tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission case of a tractor, which allows a maker to easily remodel the tractor into a work vehicle dedicated to traction, allows the tractor, once sold as the work vehicle dedicated to traction, to be easily restored to a general tractor, and allows the tractor as the work vehicle dedicated to traction to sold at a low price.SOLUTION: In the transmission case of a tractor, a PTO shaft driving mechanism 75 is provided in the transmission case 8 which transmits driving force of an engine 5 to front wheels 2 and rear wheels 3 while changing speed, and a PTO output shaft 11, which extracts power from the PTO shaft driving mechanism 75 to the outside of the transmission case 8, is connected so as to be separatable and removal by sliding in a shaft direction in the transmission case 8. Further the transmission case of a tractor, with the PTO shaft driving mechanism 75 being provided with a PTO clutch 46 for intermitting the power of the PTO output shaft 11, is mounted on a work vehicle dedicated to traction.

Description

  The present invention relates to a transmission case having a tractor power transmission mechanism used for agricultural work, civil engineering work, towing work, and the like.

  A normal tractor is provided with a traveling drive transmission mechanism that shifts the power of the engine and transmits it to the front and rear wheels and a PTO drive mechanism that drives the work machine inside the transmission case, but this is described in JP-A-2005-132269. In some cases, the tractor is used exclusively for towing.

JP 2005-132269 A

  When using a tractor as a towing-only work vehicle, the PTO output shaft that drives the work implement is not used, so not only the PTO drive mechanism is wasted, but the PTO output shaft protruding from the mission case is obstructive. It can be dangerous.

  Therefore, in the present invention, it is easy for a manufacturer to modify a tractor as a working vehicle for towing, and once it is sold as a working vehicle for towing, it can be easily returned to a normal tractor. The issue is to be able to offer cheaply.

The problems of the present invention are solved by the following technical means.
According to the first aspect of the present invention, a PTO shaft drive mechanism 75 is provided in a transmission case 8 that transmits the driving force of the engine 5 to the front wheels 2 and the rear wheels 3 and transmits the transmission force to the transmission case 8. A transmission case of a tractor is characterized in that the PTO output shaft 11 for taking out the power is slid in the axial direction in the transmission case 8 and connected so as to be separated and removable.

  The tractor according to claim 1, wherein the tractor according to claim 1 is mounted on a traction-only work vehicle with the PTO clutch 46 that intermittently powers the PTO output shaft 11 being provided in the PTO shaft drive mechanism 75. The mission case.

  The invention according to claim 3 is characterized in that the connection in the transmission case 8 of the PTO output shaft 11 is a spline fitting, and the transmission case of the tractor according to claim 1 or 2, To do.

  According to the first aspect of the present invention, the tractor and the traction vehicle can be sold as a tractor capable of driving the work machine with the PTO output shaft 11 attached, and can be sold as the tractor only when the PTO output shaft 11 is removed. Since the only difference is the presence or absence of the PTO output shaft 11, it can be mass-produced to reduce the manufacturing cost, and the towing vehicle can be sold at low cost.

  In addition to the effect of the first aspect, the invention according to the second aspect can be used as a tractor only by inserting the PTO output shaft 11 into the transmission case 8 and attaching it even once sold as a towing vehicle.

  In the invention according to claim 3, in addition to the effects of claim 1 or claim 2, it is possible to insert and assemble the PTO output shaft 11 into the mission case 8 without disassembling the mission case 8. Work is easy.

It is the whole tractor right side view. It is the whole rear view of a tractor. It is a sectional side view of the mission case for tractors. It is a sectional side view of the mission case for traction vehicles. It is front sectional drawing of a front-wheel drive shaft. It is a front sectional view of an extended front wheel drive shaft. It is a front sectional view of the extended front wheel drive shaft of another embodiment. It is an attachment part side view of an oil filter. It is a right view of the rear mission case which shows attachment of a subtransmission lever.

Examples of the present invention will be described below.
In the present specification, the left and right directions in the forward direction of the tractor are referred to as left and right, respectively, the forward direction is referred to as forward, and the reverse direction is referred to as rear.

  As shown in FIGS. 1 and 2, the tractor 1 includes a pair of left and right front wheels 2 and 2 and a pair of left and right rear wheels 3 and 3 at the front and rear of the body, and an engine output shaft 5a of the engine 5 mounted on the front of the body. Is transmitted to the front wheels 2, 2 and the rear wheels 3, 3, and a driver sits on a cockpit 6 provided in the cabin 4. A steering device such as the steering handle 7 is operated to travel.

  A hitch 9 for mounting a rotary work machine or the like is provided at the rear part of the tractor 1 so that a work machine such as a rotary work machine is driven by a PTO output shaft 11 protruding rearward from the mission case 8.

  FIG. 3 is a cross-sectional view of the tractor mission case 8, FIG. 4 is a cross-sectional view of the tow vehicle mission case 8, and the difference between them is the presence or absence of the PTO output shaft 11. First, common parts will be described. .

  The transmission case 8 is configured by integrally assembling a hollow front case 8F and a rear case 8R. The main traveling shaft 14 is pivotally supported on the main metal 9 attached to the front side in the front case 8F, and the front end of the sub traveling shaft 18 is provided. Is supported. The travel shaft 14 is connected to the engine flywheel 12 via the main clutch 16 by a damper 13 attached to the engine output shaft 5a.

  A first gear 15 that is spline-fitted to the travel shaft 14 meshes with a second gear 17 that is spline-fitted to the sub travel shaft 18, and a first PTO shaft 19 in which the gear portion 14 a of the travel shaft 14 is pivotally supported in the front case 8 F. Mesh with the first PTO gear 20.

  The rotation of the sub travel shaft 18 is transmitted to the main transmission mechanism 30, and the rotation shifted by the main transmission mechanism 30 to three forward speeds and one reverse speed is transmitted to the second travel shaft 49, and the sub travel speed is changed from the second travel shaft 49. The gear 40 is further shifted by the mechanism 40 and transmitted to the third travel shaft 35, and is transmitted from the bevel gear 45 of the third travel shaft 35 to the large bevel gear 50 to drive the rear wheel drive shaft 39.

  The main transmission mechanism 30 includes a fourth gear 27 and a fifth gear 28 in which a first transmission gear 23, a second transmission gear 24, and a fourth transmission gear 26 that are spline-fitted to the sub traveling shaft 18 are fixed to a second traveling shaft 49. The first and third gears 29 are switched and meshed to shift from the first speed to the third speed, and the third transmission gear 25 is engaged with the reverse gear 22 fixed to the idle shaft 21 to switch to the first reverse speed. The reverse gear 22, the second transmission gear 24, and the fourth gear 27 are the same.

  In the sub-transmission mechanism 40, the seventh gear 38 of the second traveling shaft 49 meshes with the eighth gear 32 fixed to the second idle shaft 31 and is transmitted in reverse, and the seventh gear 38 is splined to the third traveling shaft 35. The fifth transmission gear 36 integrated with the inner teeth 51 meshes with the ninth gear 33 fixed to the second idle shaft 31, or the sixth transmission gear 37 of the third traveling shaft 35 is the first gear. By shifting the tenth gear 34 fixed to the two idle shafts 31, the speed is changed in three stages.

  The eleventh gear 41 is fixed to the third traveling shaft 35, and the front clutch gear spline-fitted to the front wheel drive shaft 10 via the integral idle gears 42 and 43 loosely fitted to the second PTO shaft 47. The front wheel drive shaft 10 is driven by meshing with 44.

  The front end of the third travel shaft 35 is pivotally supported by the shaft end of the second travel shaft 49, and the rear portion of the third travel shaft 35 is formed in the rear case 8R with two bearings, a collar and a nut. A bevel gear 45 is formed at the rear end and is pivotally supported by a retaining ring and meshed with the large bevel gear 50 of the rear wheel drive shaft 39.

  The rotation of the first PTO shaft 19 constituting the PTO shaft drive mechanism 75 is transmitted to the second PTO shaft 47 by the PTO clutch 46 and further transmitted to the third PTO shaft 58 by the first connecting cylinder 48 which is spline-fitted. The PTO output shaft 11 is transmitted by the second connecting cylinder 60 that is spline-fitted. The PTO output shaft 11 is supported by the PTO bearing 69 on the bearing boss portion 68 of the rear case 8R. However, the PTO output shaft 11 can be pulled out and attached to the second connecting cylinder 60 with the PTO bearing 69 attached. As shown in FIG. 4, a cap 72 is attached to the bearing boss portion 68 from which the PTO output shaft 11 has been removed to close the hole, and a mission case for a towing vehicle is obtained.

  Therefore, when the tractor equipped with this mission case 8 is used as a towing-only work vehicle that does not need to drive the work machine, the production price is obtained by using the mission case of FIG. 4 with the PTO output shaft 11 removed. Since the end of the PTO output shaft 11 does not protrude from the mission case 8, it is safe. Further, when the work vehicle dedicated to towing is remodeled into a tractor that drives the work machine, it is only necessary to insert the PTO output shaft 11 into the mission case 8, and the remodeling cost can be reduced.

  FIG. 5 shows a portion of the front wheel drive shaft 10 that protrudes forward from the front case 8F. The front end of the front wheel drive shaft 10 is pivotally supported by a bearing hole 52 with a bearing 53 and an oil seal 54, and further the bearing hole 52 The insertion portion 55a of the tube receiving boss 55 is inserted outside the housing, and the flange portion 55b is fixed to the outer wall of the front case 8F with a bolt 59. The insertion depth of the insertion portion 55a is shorter than the distance between the front case 8F and the oil pan 60, and the tube receiving boss 55 can be lifted from below and inserted into the bearing hole portion 52.

An extended front wheel drive shaft 57 is connected to the front wheel drive shaft 10 by a spline sleeve 56, and an end portion of a protective cylinder 58 that encloses the extended front wheel drive shaft 57 is inserted into and supported by the cylinder receiving boss 55.
The extended front wheel drive shaft 57 is provided in the front-rear direction at the left and right center of the fuselage. As shown in FIG. 6 or FIG. 7, the protective cylinder 58 that wraps the extended front wheel drive shaft 57 is passed through the central recess of the oil pan 60, and the bottom portion. Alternatively, the tube receiving bracket 61 is attached to the receiving mounting portion 60 a provided on the side portion with the bolt 62 to receive the protective cylinder 58.

  FIG. 8 shows two oil filter mounting surfaces 63, 63 provided in the rear case 8R, each having a lower oil port 63a and an upper oil port 63b, and the oil filter mounting surface 63 being inclined by about 3 degrees to Attach to the outside. With this configuration, oil flows from the lower oil port 63a and the upper oil port 63b to the oil filter and returns from the central port 63c into the rear case 8R, so that air does not accumulate in the oil filter.

  FIG. 9 shows a connecting portion of the shift shaft 64 that shifts the sub transmission mechanism 40 in the rear case 8 </ b> R with the auxiliary transmission lever 67. The connecting shaft 66 that is pivotally supported by the bracket 65 serves as the shift shaft 64 and the auxiliary transmission lever 67. And a shift sensor 74 that engages the sensor bar 73 of the shift shaft 64 is fixed to the rear case 8R. Since the shift position can be adjusted by the bracket 65 and the connecting shaft 66, it is not necessary to adjust the position of the shift sensor 74.

2 Front wheel 3 Rear wheel 5 Engine 8 Mission case 11 PTO output shaft 46 PTO clutch 53 PTO shaft drive mechanism

Claims (3)

  A PTO shaft drive mechanism (75) is provided in a transmission case (8) that transmits the driving force of the engine (5) to the front wheels (2) and the rear wheels (3). A tractor transmission case characterized in that a PTO output shaft (11) for taking out power out of the transmission case (8) is slidably connected in the axial direction within the transmission case (8) so as to be detachable.   The tractor transmission case according to claim 1, wherein the PTO shaft drive mechanism (75) is mounted on a towing-dedicated work vehicle with a PTO clutch (46) for intermittently powering the PTO output shaft (11) provided. .   The tractor transmission case according to any one of claims 1 and 2, characterized in that the connection in the transmission case (8) of the PTO output shaft (11) is a spline fitting.

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