JP2005114128A - Power transmission of running work machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the downsizing/weight reduction and improve the maintenance performance of the differential gear mechanism when installing an engine on the front part of the running body where at least supporting both rear wheels on right and left and a mission case on the rear part respectively, and providing a PTO shaft to a work machine with the running work machine having the transmission mechanism and the differential gear mechanism to the above both rear wheels. <P>SOLUTION: Beside an opening part 8b facing to the differential gear mechanism is provided on the rear side face 8a in a mission case, a rear face plate 52 for closing the above opening is installed to be attachable or removable, an assembled hydraulic motor 17 with an output shaft on a PTO shaft 16 is installed on the rear face of this rear face plate, and the pressurized working oil with the hydraulic pump driven by an engine is supplied to this hydraulic motor 17. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a traveling work machine such as a tractor used for agricultural work or a wheel loader used for civil engineering work, and is connected or towed to a traveling wheel in the traveling machine body and the traveling work machine by an engine mounted thereon. The present invention relates to a power transmission device for driving various working machines.

In general, in a traveling work machine such as a tractor or a wheel loader described above, an engine is mounted on the front part of the traveling machine body and a transmission case is mounted on the rear part thereof, and the power of the engine is transmitted to the transmission case. The left and right rear wheels are driven to rotate by power transmission from the case, while the PTO shaft that transmits power from the engine projects backward on the rear end face of the transmission case and is output from the PTO shaft to various working machines. It is configured to do.

In this case, in the conventional traveling working machine, for example, as described in Patent Document 1 or the like, inside the transmission case, while providing a differential gear mechanism for power transmission for said Ryo rear wheels, wherein The PTO shaft passes through the rear side plate in the mission case, and is pivotally supported by the rear side plate and a partition plate provided integrally with a rear portion in the mission case, and the rear side plate and the partition A transmission mechanism for the PTO shaft is provided between the plate and the plate.
JP 7-117500 A

However, conventionally, the rear side plate in the transmission case is configured to be detachable from the transmission case, but a partition plate for supporting the PTO shaft is integrated in the back of the rear side plate. by being provided, in other words, be removed the post side plate, in its back, by the in the partition plate exists, inspection or the like for the differential gear mechanism of the both rear wheels maintenance, not only can not be performed by simply removing the rear side plate, to the rear side plate by the PTO shaft penetrates, from be removed after this side plate is troublesome, the difference There is a problem that the maintenance of the dynamic gear mechanism such as inspection is extremely troublesome.

Moreover, the the PTO shaft, in addition to the speed change mechanism with respect to the PTO shaft, or rotate the PTO shaft, require a clutch mechanism for operating to or stop the rotation, the structure is allowed made in complex Therefore, there is a problem that not only the price is greatly increased, but also an increase in weight and a large size are caused.

  This invention makes it a technical subject to eliminate these problems.

In order to achieve this technical problem, claim 1 of the present invention provides:
The engine in the front of the traveling machine body comprising supports in the "at least left and right rear wheels, respectively mounted transmission case to the rear, in the transmission case is provided with a speed change mechanism and a differential gear mechanism for the two rear wheels In the traveling work machine consisting of
The rear side of the transmission case, with an opening facing the differential gear mechanism, the mounting side plate removably After closing the opening, the rear face of the after side plates,
A hydraulic motor having an output shaft as a PTO shaft is mounted, and hydraulic oil pressurized by the hydraulic pump is supplied to the hydraulic motor between the hydraulic motor and a hydraulic pump driven by the engine. A hydraulic circuit for returning the discharged hydraulic oil to the hydraulic pump is provided. "
It is characterized by that.

Further, claim 2 of the present invention provides
“In the description of claim 1, a portion of the rear side plate to which the hydraulic motor is attached is recessed in the mission case.”
It is characterized by that.

In the configuration described in claim 1, since the PTO shaft does not penetrate the rear side plate that is detachably attached to the transmission case, the rear side plate can be removed from the transmission case extremely easily. can be, and, by removing the after side plate, the opening is opened in the rear surface of the transmission case, through the opening, because it is possible to perform the maintenance and inspection of the differential gear mechanism for both rear wheels , it is possible to significantly reduce the labor required for the maintenance and inspection of the differential gear mechanism.

  In addition, since the output shaft of the hydraulic motor attached to the rear surface of the rear side plate is a PTO shaft, shifting of the PTO shaft and rotating or stopping the rotation of the PTO shaft can be performed. Since it can be performed by a hydraulic motor, and its structure is significantly simpler than before, it is possible to achieve a reduction in price and to achieve a reduction in size and weight.

  By the way, in this type of traveling work machine, a configuration is provided in which various work machines such as a tillage machine are mounted at the rear part, and a lifting mechanism for the work machine is provided at the rear part of the upper surface of the transmission case. By doing so, it is necessary to configure the rear portion of the upper surface of the mission case to be positioned as far back as possible so that the lifting mechanism attached to the rear portion of the upper surface is close to the work implement. Positioning the rear part of the upper surface of the transmission case rearward means that the PTO shaft is also positioned rearward, so when this PTO shaft and the working machine are connected by a flexible power transmission shaft, The bending angle of the power transmission shaft with respect to the PTO shaft increases.

  In contrast, the present invention proposes the configuration described in claim 2.

  According to this configuration, the portion of the rear side plate where the hydraulic motor is attached to the hydraulic pump, and thus the PTO shaft, is attached to the transmission case, rather than the rear portion of the upper surface of the transmission case. Since it can be positioned in front of the recessed part, in the case where the working machine driven by the power transmission from the engine is attached to the rear part of the traveling working machine so as to move up and down by the lifting mechanism, The bending angle of the power transmission shaft with respect to the PTO shaft can be reduced under the condition that the lifting mechanism is close to the working machine.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, drawings when an embodiment of the present invention is applied to a tractor as a traveling work machine will be described.

1 and 2 show a tractor 1, which supports a traveling machine body 2 with a pair of left and right rear wheels 4 as well as a pair of left and right front wheels 3 and is mounted on a front portion of the traveling machine body 2. The engine 5 is configured to travel forward by driving the rear wheels 4 and the front wheels 3, and on the upper surface of the traveling machine body 2, the control seat 6 and the front wheels 3 are moved left and right. A steering handle 7 adapted to be steered by moving is provided, and the rotation of the engine 5 is appropriately shifted at the rear part of the traveling machine body 2 and transmitted to the rear wheels 4 and the front wheels 3. A mission case 8 is installed.

  In this case, the rear wheels 4 are detachably attached to the transmission case 8 so as to protrude outwardly from the outer surface of the transmission case 8, and the outer side of the axle case 9. It is attached via a gear case 10 that is attached to the end so as to extend rearward.

  A gear case 11 that covers the drive shaft 5 a on the engine 5 side is attached to the rear side of the engine 5, and a gear train mechanism 12 in the gear case 11 is provided under the gear case 11 from the drive shaft 5 a. The main shaft 13 to which power is transmitted is provided so as to protrude rearward, and further, the rear surface of the gear case 11 is hydraulic to a working machine lifting mechanism 15 and a working machine hydraulic motor described below. A working hydraulic pump 14 is attached so as to be directly connected to the drive shaft 5a.

  A hydraulic working machine lifting mechanism 15 for lifting and lowering a working machine (not shown) such as a tiller connected to the rear part of the traveling machine body 2 can be attached to and detached from the upper surface of the rear part of the mission case 8. Installed on. Furthermore, a working machine hydraulic motor 17 having an output shaft configured as a PTO shaft 16 for a working machine such as a tiller is provided on the rear side surface 8a of the transmission case 8 so that the PTO shaft 16 projects rearward. Removably attached.

  Although not shown, between the hydraulic pump 14, the working machine lifting mechanism 15 and the working machine hydraulic motor 17, hydraulic oil pressurized by the hydraulic pump 14 is supplied between the lifting mechanism 15 and the hydraulic motor 17. A hydraulic circuit is provided that is supplied to one or both of them, and returns the hydraulic oil discharged from either or both of the lifting mechanism 15 and the hydraulic motor 17 to the hydraulic pump 14. In this hydraulic circuit, the hydraulic switching valve for switching the raising / lowering mechanism 15 to three stages of raising, lowering and raising / lowering stop and the hydraulic motor 17 are arranged in three stages of forward rotation, reverse rotation and rotation stop. In addition to a hydraulic switching valve for switching, a flow rate control valve for shifting the rotational speed of the hydraulic motor 17 is also provided.

  A telescopic power transmission shaft 19 having a universal shaft joint at both ends between the main shaft 13 projecting rearward from the gear case 11 and the input shaft 18 projecting forward from the front surface of the transmission case 8. And the rotation of the engine 5 is transferred from the drive shaft 5a to the input shaft 18 in the transmission case 8 through the gear train mechanism 12, the main drive shaft 13 and the power transmission shaft 19 in the gear case 11. Then, the transmission is appropriately shifted by a hydraulic / mechanical transmission mechanism (HMT) in the transmission case 8 and transmitted to the rear wheel 4 and both front wheels 3.

  As described below, the hydraulic / mechanical transmission mechanism (HMT) includes a transmission hydraulic pump 20 and a hydraulic continuously variable transmission mechanism (HST) 22 including a transmission hydraulic motor 21 operated by the hydraulic pump 20; A planetary gear mechanism 25 is used in combination with a gear-type transmission mechanism 24 that is speed-changed by a clutch 23.

That is, as shown in FIG. 3, the transmission hydraulic pump 20 and the transmission hydraulic motor 21 are arranged on the front surface of the transmission case 8 on the hydraulic input shaft 26 and the hydraulic output shaft 27 that are pivotally supported in the transmission case 8. The gear 28 fixed on the input shaft 18 is meshed with an input gear 30 that is rotatably fitted on a sun gear shaft 29 in the planetary gear mechanism 25. A plurality of planetary gears 32 are rotatably supported on a carrier 31 fixed to the input gear 30 via a support shaft 33, and each planetary gear 32 is fixed to the sun gear shaft 29. 34 and an inner ring gear 35 that is rotatably fitted on the sun gear shaft 29.

  Next, the gear 36 fixed to the inner ring gear 35 is meshed with a gear 37 fixed to the hydraulic input shaft 26 to rotationally drive the transmission hydraulic pump 20, while the hydraulic output shaft 27 is rotated. The rotation of the transmission hydraulic motor 21 is transmitted to the sun gear shaft 29 by meshing the gear 38 fixed on the top with the gear 39 fixed on the sun gear shaft 29.

  On the other hand, a rear wheel propulsion shaft 40 is pivotally supported in the transmission case 8, and the rear end of the propulsion shaft 40 is connected to a differential gear mechanism 41 for both the rear wheels 4, thereby The rear wheel 4 is configured to be driven to rotate by the wheel propulsion shaft 40, while the gear 42 fixed on the propulsion shaft 40 is supported on the front wheel propulsion shaft 43 that is pivotally supported in the mission case 8. A telescopic power having a universal shaft joint at both ends between the front wheel propulsion shaft 43 and the differential gear mechanism 45 for the front wheels 3. When a clutch 47 is provided on the front wheel propulsion shaft 43 and the clutch 47 is operated so as to fix the gear 44 to the propulsion shaft 43. The front wheels are driven by the rear wheel propulsion shaft 40. 3 is rotated, the clutch 47, when operating so as not to fix the gear 44 relative to the propeller shaft 43, constituting the two front wheels 3 so as not to rotate.

  In the gear-type transmission mechanism 24, a gear 39 in which one small-diameter transmission gear 48 out of two transmission gears 48 and 49 rotatably fitted on the rear wheel propulsion shaft 40 is fixed on the sun gear shaft 29. Further, the other large-diameter transmission gear 49 is engaged with the gear 50 fixed on the sun gear shaft 29, and the clutch 23 in the gear-type transmission mechanism 24 is propelled by the small-diameter transmission gear 48 in the clutch 23. When operated so as to be fixed to the shaft 40, the propulsion shaft 40 is rotated at a high speed, and the clutch 23 is fixed to the other large-diameter transmission gear 49 with respect to the propulsion shaft 40 by the clutch 23. When operated, the propulsion shaft 40 is rotated at a low speed, and the clutch 23 is fixed in the middle, that is, neither of the transmission gears 48, 49 is fixed to the propulsion shaft 40. When operated upright, the rotation transmission to the propulsion shaft 40 is interrupted, and further, between the high-speed rotation by one small-diameter transmission gear 48 and the low-speed rotation by the other large-diameter transmission gear 49, A hydraulic continuously variable transmission mechanism (HST) 22 is configured to change continuously.

  The rear wheel propulsion shaft 40 is provided with a brake mechanism 51 for the propulsion shaft 40.

  When the hydraulic motor 17 having the output shaft configured as the PTO shaft 16 is detachably attached to the rear side surface 8a of the mission case 8, as shown in FIG. 3 and FIG. The side surface 8a is provided with an opening 8b that allows the rear wheel differential gear mechanism 41 provided in the transmission case 8 to be viewed, and the rear side that closes the opening 8b. The face plate 52 is detachably mounted by fastening with a plurality of bolts 53 around the periphery of the face plate 52, and a portion of the rear side face plate 52 inside the periphery is recessed within the mission case 8 by an appropriate dimension S. The hydraulic motor 17 is detachably attached to the rear side of the recessed portion.

That is, the rear side surface 8a of the transmission case 8, with overlooking an opening 8b in the differential for the rear wheels movement gear mechanism 41, the mounting side plate 52 removably After closing the opening 8b, the side plates after this In addition to the configuration in which the hydraulic motor 17 is attached to the rear surface in 51, the portion of the rear side plate 52 to which the hydraulic motor 17 is attached is recessed in the transmission case 8 by an appropriate dimension S. It is configured to do.

  As the working oil circulating between the working hydraulic pump 14, the working machine lifting mechanism 15 and the working machine hydraulic motor 17, the lubricating oil in the transmission case 8 is used as in the prior art. However, it may be configured to use another oil distinguished from this lubricating oil. By configuring in this way, deterioration of the lubricating oil and hydraulic oil can be reduced, and the hydraulic oil can be made of metal. It is possible to avoid mixing of wastes.

In this configuration, the rear side plate 52 that is detachably attached to the mission case 8 does not penetrate the PTO shaft, so that the rear side plate 52 can be removed from the mission case 8 very easily. and by removing the side plate 52 after this, the opening 8b on the side 8a after the transmission case 8 is opened, maintenance and inspection of the differential gear mechanism 41 for this opening 8b, both rear wheels 4 since it is possible to perform, it is possible to significantly reduce the labor required for the maintenance and inspection of the differential gear mechanism 41.

  In addition, since the output shaft of the hydraulic motor 17 attached to the rear surface of the rear side plate 52 is the PTO shaft 16, the speed of the PTO shaft 16 is changed, and the PTO shaft 16 is rotated or stopped. Can be performed by the control of the hydraulic motor 17, and the structure thereof is remarkably simpler than before, so that it is possible to achieve a reduction in price and to achieve a reduction in size and weight.

  Further, a portion of the rear side plate 52 to which the hydraulic motor 17 is attached is recessed in the transmission case 8 by an appropriate dimension S, so that the PTO shaft 16 in the hydraulic pump 17 is moved to the rear side. The portion of the face plate 52 to which the hydraulic motor 17 is attached can be positioned forward by the dimension S that is recessed in the mission case 8.

It is a side view which shows the tractor to which embodiment of this invention is applied. It is a top view of FIG. It is a skeleton diagram of power transmission. It is a partially cutaway side view which shows the principal part of a mission case. FIG. 5 is an enlarged sectional view taken along line VV in FIG. 4.

Explanation of symbols

1 tractor 2 traveling vehicle body 3 front wheel wheel 5 the engine 8 after the transmission case 8a differential gear mechanism 52 for post side 8b openings 14 work hydraulic pump 17 implement hydraulic motor 16 PTO shaft 41 rear wheels of the transmission case after 4 Side plate

Claims (2)

An engine is mounted on the front part of a traveling machine body supported by at least left and right rear wheels, and a transmission case is mounted on the rear part. A transmission mechanism and an operating gear mechanism for the rear wheels are provided in the transmission case. In traveling work machines,
A power transmission device for a traveling work machine, comprising a hydraulic circuit for supplying hydraulic oil to a hydraulic motor and returning hydraulic oil discharged from the hydraulic motor to the hydraulic pump.   2. The power transmission device for a traveling work machine according to claim 1, wherein a portion of the rear side plate to which the hydraulic motor is attached is recessed in the transmission case.

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