JPS6321448Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a front wheel drive power extraction device for a four-wheel power vehicle such as an agricultural tractor.

Conventionally, in four-wheel drive tractors, the power from the transmission mechanism is received by a front wheel drive shaft installed in a case such as a clutch housing, and from the front wheel drive gear attached to this front wheel drive shaft, the power is transferred to an idle gear and a front wheel drive extraction gear. There is a device in which the output is transmitted to the output gear, and the front wheels are driven from the output gear via the front wheel drive output shaft.

On the other hand, in such four-wheel drive vehicles, there are cases where the front and rear tires have two or more types of tire specifications with different diameters, and in that case, it is necessary to adjust the speed ratio of the front and rear wheels as the specifications change. . To do this, it is customary to replace the front wheel drive gear, intermediate gear, and power take-off gear and change their combination, but conventionally, disassembling and assembling them is difficult and requires a lot of effort. It was flawed. FIG. 1 shows an example of this type of front wheel drive power extraction device. As shown, front wheel drive shaft 1
is supported at its front end and middle by a front partition wall 3 and a rear support wall 4 provided in the clutch housing 2, and its rear end is supported by a front end of a drive pinion shaft 6 that protrudes from the transmission mechanism 5. Match it to,
A clutch 7 provided on both wheels is configured to switch between four-wheel drive and rear-wheel drive, and a front-wheel drive gear 8 is attached to the front-wheel drive shaft 1 between the partition wall 3 and the support wall 4. There is. On the other hand, an opening 30 is provided on the lower surface of the clutch housing 2, located below the front wheel drive gear 8.
A front wheel drive extraction case 13 is installed so as to close this opening 30, and includes an intermediate shaft 9, a front wheel drive extraction shaft 10, and an intermediate gear 11 and a front wheel drive extraction gear 12 that are attached to these and mesh with each other. The front wheel drive extraction gear 12 is housed inside the extraction case 13, while a support portion 31 for the intermediate gear 11 is provided outside the extraction case 13. It stands out. That is, in the clutch housing 2, the intermediate gear 11 is meshed with the front wheel drive gear 8, and these gears 8, 11,
Power is transmitted to the front wheel drive take-out shaft 10 via 12,
It is configured to drive a front wheel (not shown) from the extraction shaft 10.

Although not shown, a front wheel differential case is disposed at approximately the same ground height as the extraction shaft 10, and the front wheels are driven via this differential case. 14 is a main shaft that transmits power from the engine.

In this case, since the support portion 31 of the intermediate gear 11 is housed inside the clutch housing 2, the overall shape of the front wheel drive take-out case 13 can be made smaller, and the amount of downward protrusion of the clutch housing 2 is reduced. There is a great advantage that the ground clearance is increased, and as a result, damage to the front wheel drive system is prevented, and furthermore, the front wheel differential case disposed in front of the extraction case 13 can be easily aligned. However, on the other hand, when changing the specifications and replacing the three gears 8, 11, 12 to change their combination, the front wheel drive extraction gear 1
2 and the intermediate gear 11 can be easily replaced by removing the take-out case 13, but the front wheel drive gear 8
Since it is sandwiched between the gear 8 and the support wall 4, it cannot be easily removed, and the front wheel drive shaft 1 supporting the gear 8 must be removed by disassembling the clutch housing 2.

Further, FIG. 2 shows a structure equipped with a creep mechanism. The same is true for this, and since the front wheel drive shaft 8 is similarly installed together with the creep idle gear 15 between the partition wall 3 and the bearing wall 4, there is a drawback that the front wheel drive shaft 1 must be removed. .

In Japanese Utility Model Application No. 54-95726, a front wheel drive gear is mounted with the end of a PTO drive shaft mounted in a housing as an open end, and the front wheel drive gear is made to protrude from an opening formed on the lower surface of the housing. A configuration has been disclosed in which the power is extracted as rotational power, but in this prior art, there is no space around the open end from which the front wheel drive gear can be extracted, so the PTO drive shaft is slid or The front wheel drive gear cannot be attached or removed unless it is pulled out. In addition, since the front wheel drive gear protrudes from the lower surface of the housing as mentioned above, extra space is required to accommodate the intermediate gear in the power take-off gear case attached to the lower surface of the housing, and the lower This causes the front wheels to protrude, lowering the ground clearance and risking damage to the front wheel drive system while driving.Furthermore, the difference in height between the front wheels and the differential case increases, making centering difficult. .

In view of these problems, the present invention aims to provide a structure that allows easy removal and replacement of the front wheel drive gear. 4, a front wheel drive shaft 1 which receives power from a transmission mechanism is supported, one end of the front wheel drive shaft 1 is made to protrude from the support wall 4 to form an open end 17, and a front wheel drive gear 8 is attached to this open end 17. on the other hand,
An opening 30 that opens the lower surface of the housing 2,
Provided below the front wheel drive gear 8, this opening 3
The case 13 of the front wheel drive extraction gear 12 is removably attached so as to cover the
A support part 31 for the intermediate gear 11 is provided on the outside and is housed in the housing 2, while the power from the front wheel drive gear 8 is transferred to the front wheel drive extraction shaft 10 via the intermediate gear 11 and the front wheel drive extraction gear 12. The present invention is characterized in that a space 20 is provided around the open end 17 from which the front wheel drive gear 8 can be taken out without moving the front wheel drive shaft 1. Hereinafter, a detailed description will be given based on the illustrated embodiment.

Now, FIG. 3 shows an embodiment in which the creep mechanism corresponding to FIG. The front wheel drive shaft 1 inserted into the cylindrical portion 4a is inserted into the cylindrical portion 4a.
It is supported by two front and rear bearings 16a and 16b inside a, and the front end of the front wheel drive shaft 1 is made to protrude forward from the cylindrical part 4a of this support wall 4, thereby forming an unsupported open end 17. , its open end 17
The front wheel drive gear 8 is attached to the spline 18 formed by inserting it from the front side, and the front wheel drive gear 8 has a bearing 16a on the front side and an open end 1.
It is fixed by a retaining ring 19 attached to the front end of 7. Therefore, in the conventional example, the partition wall 3 that supported the front end of the front wheel drive shaft 1 is only supported on the main shaft 14, and the gap 20 between the partition wall 3 and the front end surface of the front wheel drive shaft 1 is , the open end 1 of the front wheel drive shaft 1 is larger than the width of the front wheel drive gear 8.
A space is provided around 7 from which only the front wheel drive gear 8 can be extracted.

Therefore, according to this embodiment, the front wheel drive gear 8 can be easily pulled out from the front end of the front wheel drive shaft 1 by removing the retaining ring 19.
There is no need to remove the front wheel drive gear 8, making it extremely easy to replace the front wheel drive gear 8. Furthermore, during the attachment/detachment work, since the opening 30 after removing the front wheel drive extraction case 13 opens largely below the front wheel drive gear 8, the gap 20 around the open end 17 from the opening 30 opens. All you have to do is insert your hand into it, making it extremely easy to work with. In addition, not only when exchanging
Even when switching this device from one equipped with a four-wheel drive device to one equipped only with rear wheel drive, such a switch can be easily performed since the front wheel drive gear 8 can be easily taken out. In that case, either a spacer is interposed in the part where the front wheel drive gear 8 was inserted, or the front wheel drive shaft 1 is inserted in the part corresponding to the front side of the front bearing 16a.
In this case, a retaining ring groove 21 may be formed in advance, and the retaining ring may be fitted therein.

Next, the embodiment shown in FIG. 4 is an embodiment in which a creep mechanism is provided, and in this embodiment,
The part of the partition wall 3 that supports the main shaft 14 is made into a cylindrical shape, and the lower surface of the cylindrical part 22 extends downward to form a front side support wall 23 for the front wheel drive shaft 1. is supported via bearings 16a and 16b by this front side support wall 23 and the rear side support wall 4 extended from the clutch housing 2 wall as in the conventional case, and its front end is supported by the front side support wall 4. An open end 17 is made to protrude forward from the wall 23, and a front wheel drive gear 8 is inserted and attached to the spline 18 of the open end 17, and the front wheel drive gear 8 is fixed in the longitudinal direction as shown in FIG. As in the case of , this is achieved by the retaining ring 19 attached to the open end 17 and the bearing 16a. The removal of the front wheel drive gear 8 in this case is the same as in the case of FIG. 3. Also in this embodiment, the gap 20 between the front end of the front wheel drive shaft 1 and the partition wall 3 is made larger than the width of the front wheel drive gear 8, and the retaining ring groove 21 for switching only between four-wheel drive and rear wheel drive is provided in advance, which is the same as in FIG.

In addition, in FIG. 4, 24 is the main shaft 14.
The coupling ring 26 that connects the PTO shaft 25 is
A pinion gear 27 is formed on the outer periphery of the rear end of the coupling ring 24, and an input shaft 28 is rotatably fitted onto the PTO shaft 25 and transmits power to the rear transmission mechanism, and an input shaft 28 slides on the front end of the input shaft 27. The freely attached creep slide gear 29 is a creep reduction gear that is loosely fitted to the front wheel drive shaft 1. Although detailed explanation will be omitted, the slide gear 28 can be slid to switch between creep driving and normal driving. It is something to do.

As described above, according to the present invention, one end of the front wheel drive shaft supported by the support wall in the housing is
An open end protrudes from the support wall, and a front wheel drive gear is attached to the open end, and an opening in the lower surface of the housing is provided below the drive gear, and the front wheel drive gear is provided so as to close this opening. The case of the drive extraction gear is detachably attached, and a support part for the intermediate gear is provided on the outside of the case and is housed in the housing. Since a space is provided in which the gear can be extracted, the case of the extraction gear does not protrude significantly downward from the housing, making it possible to maintain a high ground clearance, preventing damage to the front wheel drive system, and The front wheels can be easily aligned with the differential case, and the front wheel drive gear provided in the housing can be easily attached and detached. In addition, work to change gear combinations due to changes in tire specifications,
Switching between four-wheel drive and rear-wheel drive only can be done in an extremely short time, and the compatibility between four-wheel drive and rear-wheel drive is highly compatible. It is something.

[Brief explanation of the drawing]

1 and 2 show an example of a front wheel drive power take-off device. FIGS. 3 and 4 are longitudinal sectional views of the rear part of the clutch housing, respectively, showing an embodiment of the present invention. 1...Front wheel drive shaft, 2...Clutch housing, 3...Partition wall, 4, 23...Support wall, 8...
Front wheel drive gear, 10...Front wheel drive extraction shaft, 12...
...Front wheel drive extraction gear, 17...Open end, 20...
Gap (part of space), 30...opening, 31...
Bearing part.

Claims (1)

[Scope of utility model registration request] A front wheel drive shaft that receives power from a transmission mechanism is supported on a support wall provided in a housing such as a clutch housing or a transmission case, and one end of the front wheel drive shaft is made to protrude from the support wall and is an open end. The front wheel drive gear is attached to the open end, while the opening on the lower surface of the housing is
A case of the front wheel drive extraction gear is provided below the front wheel drive gear, and a case of the front wheel drive extraction gear is removably attached so as to close this opening, and a support part for the intermediate gear is provided on the outside of the case and is housed in the housing. On the other hand, the front wheel drive shaft is configured to extract power from the front wheel drive gear to the front wheel drive output shaft via an intermediate gear and the front wheel drive output gear to drive the front wheels, and to move the front wheel drive shaft around the open end. A front wheel drive power extraction device characterized by providing a space from which a front wheel drive gear can be extracted without any problem.