JP5537481B2 - Front wheel drive device for work vehicle - Google Patents

Description

The present invention includes a differential mechanism built in a front axle case, a transmission shaft and a universal joint that transmits power from a transmission to the differential mechanism, and a cover that covers the universal joint. The present invention relates to a front wheel drive device for a work vehicle in which a joint includes a grease nipple that can supply oil to a relative rotation portion of the universal joint.

  In the above-described front wheel drive device for a work vehicle, conventionally, in order to supply oil to the relative rotation portion of the universal joint, it is necessary to remove the cover that covers the universal joint and connect the nozzle of the grease gun to the grease nipple (for example, Patent Document 1).

JP-A-10-196668

For this reason, since it is necessary to attach and detach the cover when refueling with the grease gun, there is a possibility that the refueling work may be troublesome.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a front wheel drive device for a work vehicle that can easily supply oil to a relative rotation portion of a universal joint with a grease gun.

The feature of the present invention is that
A differential mechanism built in a front axle case, a transmission shaft and a universal joint that transmits power from the transmission to the differential mechanism, and a cover that covers the universal joint, the universal joints being mutually It includes a pair of bifurcated yokes opposed, cross spider cruciform provided over the pair of yokes, and a grease nipple which can lubricate the relative rotation of the cross spider, the differential mechanism Is provided at the front lower side of the transmission, and the transmission shaft is provided in a front-lowering state. The grease nipple extends from the front surface of the cross spider to the front side of the transmission shaft, and rotates the universal joint. Accordingly, when the grease nipple is in a downward posture, the tip of the grease nipple is bent so as to face downward, and when the grease nipple is in a downward posture, A pair of arms constituting a bifurcated yoke located on the opposite side of the transmission shaft side of the yoke of the pair of yoke, so that the state of overlapping in side view, wherein the universal joint is constructed, wherein the cover comprising said grease nipple and opening for connecting can be inserted and the nozzle of grease gun to the grease nipple is formed in a position opposite to one of the lower surface of the cover, and a cap freely open and close the opening There is in point.

In the front wheel drive device for a working vehicle having this configuration, the cover includes an opening for inserting the nozzle of the grease gun so as to be connectable to the grease nipple, and a cap capable of opening and closing the opening.
For this reason, when lubricating the relative rotation part of the universal joint with the grease gun, the grease gun nozzle can be inserted and connected to the grease nipple from the opening provided in the cover without removing the cover covering the universal joint. .
In addition, since the cap that can be opened and closed is provided, the cap is closed with a cap when refueling is not necessary, preventing intrusion into the cover through the aperture such as splashed stones or water drops. can do.
Therefore, if it is the front-wheel drive device of the working vehicle of this structure, it can supply oil to the relative rotation part in a universal joint simply with a grease gun.
Another feature of the present invention is that
A differential mechanism built in a front axle case, a transmission shaft and a universal joint that transmits power from the transmission to the differential mechanism, and a cover that covers the universal joint, and the universal joint includes A grease nipple capable of refueling is provided at a relative rotation portion of a universal joint, and the cover includes an opening for inserting a nozzle of a grease gun to be connectable to the grease nipple, and a cap capable of opening and closing the opening. And a protection plate for protecting the cover from the outside of the cover, wherein the protection plate is detachably fixed so that the plate surface faces the cap.

In the present invention ,
A protective plate for protecting the front Symbol cover from the cover outside, the protective plate, it is preferable that the plate surface is detachably fixed so as to be in contact with the cap.

  With this configuration, it is possible to prevent the cover from being damaged by the stone that has been flipped up, and to prevent the cap that closes the opening from falling off or being damaged.

It is a side view which shows a tractor. It is a side view which shows a front-wheel drive device. It is a side view which shows the inside of a cover. It is the IV-IV arrow directional view in FIG. It is a side view which shows the oil supply method.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 4 show an agricultural tractor equipped with a front wheel drive device A according to the present invention.
As shown in FIG. 1, the tractor includes an engine 2, a clutch housing 3 connected to the rear portion of the engine 2 and including a clutch, a vehicle body frame 1 a that connects the clutch housing 3 and a transmission case 7 at the rear of the vehicle body, and a front of the vehicle body A front frame 1b connected to the engine 2 so as to protrude toward the side, a pair of left and right front wheels 4 supported by the front frame 1b, a pair of left and right rear wheels 8 supported by the transmission case 7, and a body frame A steering handle 5 disposed above the front of 1a, a driver's seat 6 disposed above the mission case 7, and the like are provided.

The transmission case 7 is equipped with a hydrostatic continuously variable transmission (hereinafter abbreviated as HST) 9, and the power of the engine 2 is transmitted from the clutch housing 3 to the HST 9 via the first transmission shaft 10. It is transmitted to the front wheel 4 and the rear wheel 8 via a built-in auxiliary transmission (not shown).

  As shown in FIG. 2, the front wheel drive device A includes a front axle case 11 provided in the front frame 1 b, a front wheel differential mechanism 12 provided in the front axle case 11, and a front wheel differential mechanism 12. And a third transmission shaft 14 for transmitting the power branched from the auxiliary transmission to the second transmission shaft 13. The power from the engine 2 is used for the front wheel differential mechanism 12. Is transmitted to the front wheel 4 via

  The third transmission shaft 14 is inclined in a posture that becomes lower toward the front side of the body. The front end of the third transmission shaft 14 is connected to the second transmission shaft 13 by a lower universal joint (universal joint) 15, and the rear end of the third transmission shaft 14 is connected to the upper universal joint (universal joint). 16 is connected to the output shaft 17 from the auxiliary transmission.

A rubber cylindrical cover 18 that covers the front half of the third transmission shaft 14 and the lower universal joint 15 in series is provided, and the cylindrical cover 18 includes a joint cover portion 23 that covers the lower universal joint 15. .
The second transmission shaft 13, the third transmission shaft 14, and the lower universal joint 15 correspond to the transmission shaft and the universal joint that transmit the power from the transmission in the present invention to the differential mechanism.

The body front side end 18a of the joint cover portion 23 is connected to a protective pipe 19 surrounding the second transmission shaft 13, and between the body rear side end 18b of the cylindrical cover 18 and the third transmission shaft 14, A cylindrical joint collar 21 is attached.
A seal member 20 is mounted between the joint collar 21 and the third transmission shaft 14.

As shown in FIG. 3, the rear side of the protective pipe 19 is fitted in an opening of a plate-like bracket 19 a that is fixed to the lower portion of the flange portion 3 a of the clutch housing 3 so that the plate surface is along the width direction of the machine body. It is supported in the state.
The second transmission shaft 13 is supported on the inner side of the protective pipe 19 through a bearing 13 a fitted inside the protective pipe 19.

A backup material 19b mounted concentrically with a later-described second yoke 25 (corresponding to “a pair of yokes”) is held inside the body rear side end portion of the protective pipe 19.
A joint cover portion 23 that is externally fitted to the rear end of the protection pipe 19 is fastened and fixed to the backup material 19b together with the protection pipe 19 by a screw-type fastening band 23a.

The cylindrical cover 18 is protected from the outside of the cover by a protective plate 22 made of sheet metal.
3 and 4, the protective plate 22 includes a horizontal bottom plate portion 22a that covers the joint cover portion 23 of the cylindrical cover 18 from the lower side, and left and right inclined side plate portions 22b that cover the lateral side. It is formed in a substantially V-shaped cross-sectional shape.

The protection plate 22 is detachably bolted to the left and right connecting portions 3b in which the left and right inclined side plate portions 22b project laterally on the left and right side surfaces of the lower portion of the clutch housing 3 with the front end of the airframe being closed by the bracket 19a. It is fixed.
For this reason, it is possible to prevent the stones and water droplets jumped up during traveling from entering the space between the protective plate 22 and the joint cover portion 23 from the front side of the machine body.

As shown in FIG. 3, the lower universal joint 15 includes a first yoke 24 (corresponding to “a pair of yokes”) provided at the front end of the third transmission shaft 14 and a second transmission shaft 13. A second yoke 25 provided at the rear end is connected to each other by a cross-shaped cross spider 26 so as to be angularly displaceable from each other.

The cross spider 26 includes four shaft portions 27 adjacent to each other at right angles so as to be arranged in a cross shape.
Each yoke 24, 25 includes two arms 24a, 25a arranged in a bifurcated shape, and a shaft portion 27 of a cross spider 26 is fitted into each arm 24a, 25a so as to be relatively rotatable. Of the two arms 24a, 25a, the arm 25a corresponds to the “pair of arms” of the present invention.

The cross spider 26 includes a grease nipple 29 capable of supplying grease to a relative rotation portion of the lower universal joint 15, that is, a relative rotation portion 28 between the shaft portion 27 of the cross spider 26 and the arms 24a and 25a. .
The cross spider 26 is formed with oil passages (not shown) communicating with the relative rotation portions 28, and the grease nipple 29 is connected to these oil passages.

  As shown in FIG. 3, the joint cover portion 23 of the cylindrical cover 18 has an opening 31 that opens downward to insert the nozzle 30 a of the grease gun 30 into a grease nipple 29 so as to be connectable, and the opening 31. And a cap 32 that can be freely opened and closed.

The opening 31 is formed by integrally forming a cylindrical portion 33 communicating with the inside of the cylindrical cover 18 in the cylindrical cover 18.
The cap 32 seals the gap between the flange 32 a formed in an annular shape so as to contact the end face of the cylindrical portion 33, the columnar plug 32 b fitted inside the cylindrical portion 33, and the plug 32 b and the cylindrical portion 33. And a rubber O-ring 32c.

The cap 32 has a plug 32 b fitted into the cylindrical portion 33 so that the flange portion 32 a contacts the end surface of the cylindrical portion 33, and is prevented from being detached by a clip 34 attached to the outer peripheral side of the cylindrical portion 33.
The protection plate 22 is fixed so that the upward surface of the bottom plate portion 22 a contacts the lower surface of the flange portion 32 a of the cap 32.

  Although not shown, the opening 31 is provided in the joint cover portion 23 so as to open in the lateral direction of the machine body, and the inner surface of the inclined side plate portion 22b is in contact with the flange portion 32a of the cap 32 attached to the opening 31. The protective plate 22 may be fixed so as to hit.

FIG. 5 shows a method of refueling with the grease gun 30 to the relative rotation portion 28 of the lower universal joint 15.
In this embodiment, after removing the protective plate 22, the clip 34, and the cap 32, the machine body is moved to forcibly rotate the front wheel 4 so that the grease nipple 29 faces the opening 31. In this state, the grease gun Thirty nozzles 30 a are inserted into the inside of the cylindrical cover 18 from the opening 31 and connected to the grease nipple 29 to supply oil.

[Other Embodiments]
1. In the above-described embodiment, the protective plate 22 may not be provided, and it may be configured such that oil can be supplied by simply removing the clip 34 and the cap 32 without removing the protective plate 22.
2. In the above embodiment, an opening larger than the cap 32 and the clip 34 is formed on the bottom plate portion 22a of the protective plate 22 on the side facing the cap 32, and a flat cover covering the opening is formed on the bottom plate portion 22a. It may be configured such that it can be removably attached, and this cover can be removed from the bottom plate portion 22a, and the clip 34 and the cap 32 can be removed to supply oil.
3. In the above-described embodiment, the universal joint including the grease nipple 29 may be the upper universal joint 16 that connects the output shaft 17 from the auxiliary transmission and the rear end portion of the third transmission shaft 14 on the machine body.
In this case, a cover for covering the upper universal joint 16 is provided, and an opening for inserting the nozzle 30a of the grease gun 30 so as to be connectable to the grease nipple 29 and a cap capable of opening and closing the opening are provided on the cover. Can be implemented.

  The present invention can be applied to a front wheel drive device of various work vehicles such as a tractor, a lawn mower, and a rice transplanter.

11 Front axle case 12 Differential mechanism 13, 14 Transmission shaft 15 Universal joint 18 Cover 22 Protection plate
24 First yoke (a pair of yokes)
25 Second yoke (a pair of yokes)
25a Arm (a pair of arms)
26 Cross spider 28 Relative rotation part 29 Grease nipple 30 Grease gun 30a Nozzle 31 Opening 32 Cap

Claims (3)

A differential mechanism built in a front axle case, a transmission shaft and a universal joint that transmit power from the transmission to the differential mechanism, and a cover that covers the universal joint,
The universal joint includes a pair of bifurcated yokes opposed to each other, the cross spider cruciform provided over the pair of yokes, and a grease nipple which can lubricate the relative rotation of the cross spider Prepared,
The differential mechanism is provided at the front lower side of the transmission, and the transmission shaft is provided in a state of lowering forward,
The grease nipple extends from the front surface of the cross spider to the front side of the transmission shaft, and the tip of the grease nipple faces downward when the grease nipple assumes a downward posture as the universal joint rotates. Bend and
When the grease nipple is in a downward posture, a pair of arms constituting a fork of the yoke located on the side opposite to the yoke on the transmission shaft side of the pair of yokes is overlapped in a side view. The universal joint is configured as follows:
The cover is formed at a position facing the grease nipple on the lower surface of the cover, and has an opening for inserting a nozzle of a grease gun so as to be connectable to the grease nipple, and a cap capable of opening and closing the opening. , work vehicle front wheel drive device comprising a. A differential mechanism built in a front axle case, a transmission shaft and a universal joint that transmit power from the transmission to the differential mechanism, and a cover that covers the universal joint,
The universal joint includes a grease nipple capable of supplying oil to a relative rotation portion of the universal joint;
The cover includes an opening for inserting a nozzle of a grease gun so as to be connectable to the grease nipple, and a cap capable of opening and closing the opening.
A protective plate for protecting the cover from the outside of the cover;
The protective plate is a front-wheel drive device for a work vehicle that is detachably fixed so that a plate surface faces the cap. A protective plate for protecting the cover from the outside of the cover;
The front wheel drive device for a work vehicle according to claim 1 or 2, wherein the protection plate is detachably fixed so that a plate surface is in contact with the cap.

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