JPH07232567A - Transmission structure of work machine - Google Patents

Abstract

(57) [Summary] [Structure] The main clutch Cr attached to the rear surface of the engine 1 at the front of the fuselage and the rear mission Mr at the rear of the fuselage are interlocked and coupled by the main transmission shaft 5, and the arrangement height of the main transmission shaft 5 is increased. The main transmission shaft 5 so that the height is lower than the height of the clutch output shaft.
And the clutch output shaft are interlocked via a gear interlocking mechanism Mf disposed on the clutch housing 2 side, and the internal space of the gear case portion 3 surrounding the gear interlocking mechanism Mf and the rear are arranged so that the lubricating oil is circulated. The internal space of the mission case Mr is communicated with a pair of upper and lower communication hoses 36 and 37. [Effect] By a relatively simple modification in which transmission cases that are separated from each other are connected by a pair of pipes, the amount of lubricating oil in the gear case can be substantially increased without increasing the size of the case, and the floor can be substantially increased. The gear case that contributes to lowering the floor can be made compact while maintaining the lubricating oil temperature at an appropriate value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission structure for a working machine such as a tractor or a lawn mower, and more particularly to a technique for obtaining a good lubrication operation of a gear case portion attached to a clutch housing.

[0002]

2. Description of the Related Art For example, as in the tractor shown in FIG. 4 of Japanese Patent Laid-Open No. 5-155260, a front mission (no reference numeral) is provided at a rear wall portion of a clutch housing to link an engine and a rear mission. It is known that the height of the transmission shaft is reduced so that the floor can be made lower.

[0003]

Therefore, in order to lower the floor, a model having a structure in which only the gear interlocking mechanism for inputting the rear mission is provided in the front mission (gear interlocking mechanism) is planned. I had some problems with that. That is, in addition to the transmission gear interlocking mechanism for inputting to the rear mission, the front transmission described above also has a P for transmitting power to the front PTO shaft.
The TO gear interlocking mechanism and the like are built-in and have a relatively large capacity, but in the case of a mission having only a traveling gear reduction mechanism, the casing thereof becomes very compact, and naturally the amount of lubricating oil inside is small.

However, since the front transmission, to which the engine speed is input, rotates at a high speed, the temperature of the lubricating oil of the limited small capacity rises too much, and the case capacity is unnecessarily large in order to prevent it. It is predicted that if the capacity is increased, the limited space is wasted, which is not preferable in any case. An object of the present invention is to devise so that the lubricating oil can be maintained in an appropriate temperature range while using a small front mission having only a transmission gear interlocking mechanism.

[0005]

In order to achieve the above object, the present invention has a clutch output shaft of a main clutch directly mounted on the engine surface, with an engine mounted on one end of the body and a mission mounted on the other end of the body. A main transmission shaft for interlocking the transmission with the transmission is provided, and the main transmission shaft and the clutch output shaft are connected to the clutch housing side so that the arrangement height level of the main transmission shaft is lower than the height level of the clutch output shaft. In addition to interlocking via the gear interlocking mechanism arranged in the, the internal space of the gear case surrounding the gear interlocking mechanism and the internal space of the mission case surrounding the mission are connected by a pair of pipes. It is a feature.

[0006]

In other words, the inside of the mission case having a large amount of lubricating oil and the inside of the gear case portion having a very small capacity are connected by a pair of pipes, so that the lubricating oil passes through the pipes and the inside of the transmission case and the gear case portion. You will be able to move back and forth and cycle. Therefore, the hydraulic oil whose temperature has risen in the gear case can be cooled in the transmission case and the pipe, and the temperature rise that is too high as in the conventional case can be eliminated.

Since a pair of pipes are provided, it is possible to circulate by using one as an outward path and the other as a return path, and in terms of cooling, stirring, etc., compared to a means for communicating with only one pipe. Clearly efficient. Also, if the gear case is independent, a lubrication hole, an oil detection hole, or a breather pipe is required. Depending on the structure that communicates with the inside of the mission case, either the transmission case or the gear case breather pipe You can also omit the kind.

[0008]

Therefore, the relatively simple modification in which the transmission cases separated from each other are communicated with each other by the pair of pipes can substantially increase the amount of lubricating oil in the gear case without increasing the size of the cases. The gear case, which contributes to lowering the floor, can be made compact and simple while maintaining the lubricating oil temperature at an appropriate value.

[0009]

Embodiments of the present invention will be described below with reference to the drawings in the case of a tractor mission. 1 shows an engine, 1 is an engine, 2 is a clutch housing, 3 is a front transmission case, 4 is a rear transmission case, 5 is a main transmission shaft, 6 is a rear PTO shaft, 7
Is the mid-PTO axis and m is the mower. Power is input to the mower m from the mid PTO shaft 7, and the mid PTO shaft 7 is supported by a protruding case 8 bolted to the lower surface of the rear mission case 4.

In this tractor, the floor 10 of the control section 9 is
The front transmission Mf is provided to lower the floor, and the position of the main transmission shaft 5 is lowered. That is, as shown in FIGS. 2 and 3, the main clutch Cr directly connected to the rear surface of the engine 1.
In providing the main transmission shaft 5 for interlockingly connecting the clutch output shaft 2a of the vehicle and the rear transmission Mr, the main transmission shaft 5
So that the arrangement height level thereof is lower than the height level of the clutch output shaft 2a.
And are interlocked via a gear interlocking mechanism Mf arranged on the clutch housing 2 side.

The dry single-plate clutch Cr has a structure in which it is turned on and off by swinging an operation arm 35 provided at the upper rear portion thereof, and the clutch housing 2 is set to a lateral truncated cone shape having a narrower diameter toward the rear side. In addition, a front transmission case (corresponding to a gear case portion) 3 is formed by bolting a gear case 3a to the rear wall 2b of the clutch housing 2. The gear interlocking mechanism Mf is configured by engaging a drive gear 11 of the clutch output shaft 2a, a driven gear 12 that is interlocked with the main transmission shaft 5, and an intermediate gear 13. A breather pipe 14 is provided on the top of the cover case 3a.

The lower rear wall of the clutch housing 2 is placed on the engine 1 side so that the internal space of the front transmission case (corresponding to the gear case portion) 3 surrounding the gear interlocking mechanism Mf bulges toward the main clutch Cr side. It is locally recessed toward. Specifically, the front bearing 15 portion that supports the intermediate gear 13 and the front bearing 16 portion that supports the driven gear 12 on the rear wall 2b are moved to the front as far as possible without contacting the main clutch Cr, and are required. The volume of the front mission case 3 is enlarged in order to secure a sufficient amount of lubricating oil. The virtual line a is the inner surface line of the conventional clutch housing rear wall.

As shown in FIGS. 1, 3 and 5, the inner space of the front mission case 3 and the inner space of the rear mission case 4 are connected by a pair of upper and lower communicating hoses (corresponding to piping) 36, 37. There is. That is, the lubricating oil passes through the upper communication hose 36 when going from the front mission Mf to the rear mission Mr, and goes through the lower communication hose 37 when going from the rear mission Mr to the front mission Mf. The inside of 4 can be circulated efficiently. As a result, the oil in the front transmission case 3 having a very small capacity is prevented from overheating and the lubricating oil is prevented from deteriorating early.

As shown in FIG. 2, the rear mission Mr.
Is a main transmission mechanism 17 for traveling, which is transmitted to the main transmission shaft 5.
, A sub-transmission mechanism 18 for traveling, a differential mechanism 19, and a PT
It is composed of an O transmission mechanism 20, a switching clutch 21 for the mid PTO shaft 7, and the like. The diff output shaft 22 of the diff mechanism 19 and the rear axle 23 are gear-interlocked with each other, and a side brake B is provided at the end of the diff output shaft 22.

As shown in FIG. 4, the side brake B is of a wet multi-plate type, and has a structure in which the brake discs 26 and 27 are pressed and released by a cam 25 which is rotated by an operation arm 24, and an axle case portion. It communicates with the inside of 28.
The drive side gear 2 integrally formed with the differential output shaft 22
A vertical hole 22a opened at the tooth bottom of 2G and a horizontal hole 22b formed parallel to the shaft end are communicated with each other.
The lubricating oil is positively sent to the brake chamber 29 by the engagement of the driven gear 23G and the driving gear 22G. As a result, even if the vehicle body is slightly tilted to the left or right, the lubricating oil is reliably sent to the brake chamber 29, and problems such as seizure and poor working efficiency can be prevented.

Further, the front and rear joints 30, 30 connecting the driven gear 12 and the input shaft 17a of the rear transmission Mr and the main transmission shaft 5 are constructed so as to be able to absorb some misalignment. That is, the front joint part 30
6, the spline portion 32 at the rear end of the driven gear 12 that meshes with the inner diameter spline portion 31 at the front end of the main transmission shaft 5 is formed in a spherical shape, and the spline portions 31 and 32 are slightly different from each other. The relative tilt of is allowed.
In addition, the spherical projection 33 protruding rearward from the rear end of the shaft portion 12a of the driven gear 12 is for receiving the contact with the main transmission shaft 5,
Also, 34 is a rubber boot.

As shown in FIGS. 7 and 8, the rear PTO shaft 6 is a PTO formed at the rear end of the rear mission case 4.
Gears are decelerated in the deceleration case 39. The PTO deceleration case 39 includes a rear case portion 4r of the rear mission case 4 and a deceleration cover 39a.
A plurality of drain holes 40 are formed in r to promote the movement of lubricating oil. In combination with the movement of lubricating oil in the bearings 41 and 42, a good oil circulation action is exhibited.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a side view of a tractor.

FIG. 2 is a diagram showing a schematic transmission structure.

FIG. 3 is a sectional side view showing a structure of a front mission.

FIG. 4 is a sectional view showing a structure of a side brake portion.

FIG. 5 is a sectional view showing a mounting position of the lubricating oil pipe on the gear case portion.

FIG. 6 is a side view of a partial cutaway showing a joint structure on the front side of the main transmission shaft.

FIG. 7 is a sectional view showing the internal structure of the PTO deceleration case.

FIG. 8 is a rear view showing the arrangement of punch holes in the PTO deceleration case.

[Explanation of symbols]

 1 Engine 2 Clutch Housing 2a Clutch Output Shaft 3 Gear Case 5 Main Transmission Shaft 36, 37 Piping Mf Gear Interlocking Mechanism Mr Mission Cr Main Clutch

Claims (1)

[Claims] 1. A clutch output shaft (2a) of a main clutch (Cr) directly mounted on the surface of the engine (1), wherein an engine (1) is mounted on one end of the body and a mission (Mr) is mounted on the other end of the body. ) And the transmission (Mr) are interlocked with each other, and a main transmission shaft (5) is provided so that the height level of the main transmission shaft (5) is lower than that of the clutch output shaft (2a). , The main transmission shaft (5) and the clutch output shaft (2a) are interlocked via a gear interlocking mechanism (Mf) arranged on the clutch housing (2) side, and the gear interlocking mechanism (Mf) is surrounded. The transmission structure of the working machine in which the internal space of the gear case portion (3) and the internal space of the mission case (Mr) surrounding the mission (Mr) are connected by a pair of pipes (36) and (37). .