JP2005001636A - Power-dividing device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power-dividing device having simple structure for a working vehicle capable of dividedly outputting a driving force inputted from a driving source into a main transmission route including a pump unit and a sub transmission route including a PTO unit. <P>SOLUTION: The power-dividing device is equipped with a case member, an input shaft supported by the case member so that a first end portion of the input shaft can be operatively connected to the driving source, the PTO unit having a PTO shaft supported by the case member so as to be offset with respect to the input shaft, a power transmission mechanism accommodated in the case member to transmit power from the input shaft to the PTO shaft, and a first pump unit having a first pump shaft operatively connected to the input shaft and being fluid-connected to an actuator disposed outside. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power branching device for a working vehicle configured to be able to branch a driving force input from a driving source into at least two systems.
[0002]
[Prior art]
Conventionally, various transmission structures have been proposed and adopted in work vehicles. For example, in a working vehicle including a pump unit operatively connected to a drive source and an actuator fluidly connected to the pump unit, a configuration in which the actuator is spaced apart from the hydraulic pump is also conventionally known.
In such a configuration, the hydraulic pump unit, together with the actuator, constitutes a main transmission path for shifting and outputting the driving force from the driving source.
[0003]
By the way, depending on the application, in a transmission structure including a hydraulic pump unit and an actuator that are spaced apart from each other, a sub power transmission path may be required separately from the main power transmission path. For example, as in a lawn mower, the power from a common drive source is branched and output to a travel system transmission path that drives the drive wheels and a PTO system transmission path that drives the mower.
[0004]
Hereinafter, a case where a hydraulic motor unit is used as the actuator will be described as an example.
In U.S. Pat. No. 4,395,865 (hereinafter referred to as known document 1) and U.S. Pat. No. 5,809,756 (hereinafter referred to as known document 2), the engine is operatively connected. Separately from the traveling system transmission path that is configured by a hydraulic pump unit and a hydraulic motor unit that is spaced apart from the hydraulic pump unit and configured to drive the drive wheels, the power from the engine is transmitted to the mower. A lawn mower having a PTO transmission path is disclosed.
[0005]
More specifically, the lawn mower described in the known document 1 is provided with first and second output shafts in an engine serving as a common drive source, and the first and second output shafts are respectively connected to a hydraulic pump unit and a mower. Is operatively connected to. That is, in the lawn mower described in the known document 1, the traveling transmission path and the PTO transmission path are completely separated.
However, in such a configuration, since the traveling transmission path and the PTO transmission path are completely separated, the number of parts constituting the transmission path increases and a large space for accommodating both transmission paths is required. .
Moreover, in a transmission structure provided with two such transmission paths, it is necessary to independently control power transmission / cutoff of each transmission path.
In this regard, in the lawn mower described in the known document 1, each transmission path is provided with an electromagnetic clutch for power transmission / interruption, but the electromagnetic clutch has poor durability, and as a result, the transmission path There is also a problem that the reliability of the system is impaired.
[0006]
On the other hand, the lawn mower described in the known document 2 is provided with a common output shaft in the engine, and the common output shaft supports the driving wheel pulley and the mower pulley, so that the common transmission shaft and the traveling system transmission path and The power can be branched to the PTO transmission path.
However, in such a configuration, there is a problem that the common output shaft must be lengthened and a large load is applied to the common output shaft.
Further, the above-mentioned known document 2 does not describe how to transmit / cut off the power of each transmission path.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above prior art, and has a simple structure capable of branching and outputting a driving force input from a driving source to a main transmission path including a pump unit and a sub-transmission path including a PTO unit. An object is to provide a power branching device for a working vehicle.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a case member, an input shaft supported by the case member so that one end can be operatively connected to a drive source, and the case member below the input shaft. A PTO unit having a PTO shaft supported on the case, a transmission mechanism housed in the case member, the transmission mechanism transmitting power from the input shaft to the PTO shaft, and operatively coupled to the input shaft. There is also provided a power branching device for a working vehicle comprising a first pump unit having a first pump shaft, the first pump unit being fluidly connected to an externally disposed actuator.
[0009]
In one aspect, the first pump shaft is operatively connected to the input shaft via the transmission mechanism.
In the one aspect, preferably, the first pump shaft is disposed between the input shaft and the PTO shaft in the vertical direction.
[0010]
In a preferred embodiment, a second pump unit having a second pump shaft operably connected to the input shaft, the second pump unit being fluidly connected to an actuator disposed outside, further comprising: Can be provided.
In the preferable aspect, the second pump shaft is operatively connected to the input shaft via the transmission mechanism.
More preferably, each component of the first and second pump units is the same.
[0011]
In the preferable aspect, when the input shaft is along the vehicle front-rear direction, for example, the first pump unit and the second pump unit are connected to the same side of the case member in the vehicle front-rear direction.
Alternatively, the first pump unit and the second pump unit may be connected to one side and the other side of the case member in the vehicle front-rear direction, respectively.
In such a replacement mode, preferably, the first and second pump shafts are arranged coaxially.
[0012]
The first pump unit and the second pump unit respectively have a base end wall having an insertion hole through which the first and second pump shafts are inserted and a peripheral portion of the base end wall in the first and second pump axial directions. First and second pump cases, each of which includes a peripheral wall having an opening on the free end side, the base end wall being connected to the case member, and first and second pump shafts driven by the first and second pump shafts. A first pump body, a first pump body housed in the first and second pump cases from the free end openings of the first and second pump cases, and the first and second pump bodies. The first and second center sections connected to the first and second pump cases may be provided so as to support the pump main body and close the free end side openings of the first and second pump cases.
[0013]
For example, the work vehicle can include a pair of left and right drive wheels and a ground work machine.
In such an aspect, the power branching device is disposed between the drive source and the ground work machine in the vehicle longitudinal direction. The input shaft is operatively connected to the output portion of the drive source, and the PTO shaft is operatively connected to the ground work machine.
The first and second pump units are fluidly connected to a pair of left and right hydraulic motor units that drive each of the pair of drive wheels.
[0014]
More preferably, a charge pump unit operatively connected to the input shaft may be further included.
[0015]
More preferably, the PTO unit may further include a PTO clutch mechanism that selectively engages / disconnects power transmission from the input shaft to the PTO shaft.
Further, the PTO unit may have a PTO brake mechanism that releases / adds a braking force to the PTO shaft in conjunction with a power transmission / cut-off operation from the input shaft to the PTO shaft by the PTO clutch mechanism. .
For example, a part of pressure oil from a charge pump unit operatively driven by the input shaft can be supplied as hydraulic oil to the PTO clutch mechanism and / or the PTO brake mechanism.
[0016]
Preferably, the input shaft and the PTO shaft are along the vehicle front-rear direction and can be located at substantially the same position in the vehicle width direction.
[0017]
In order to achieve the above object, the present invention provides a case member, an input shaft supported by the case member so that one end thereof can be operatively connected to a drive source, and the input shaft below the input shaft. A PTO shaft supported by the case member; a transmission mechanism housed in the case member; a transmission mechanism for transmitting power from the input shaft to the PTO shaft; and a operatively connected to the input shaft. A first pump unit body housed in the case member and driven by the first pump shaft, the first pump unit body fluidly connected to an externally disposed actuator A power branching device for a working vehicle comprising:
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of a power split device according to the present invention will be described with reference to the accompanying drawings.
The power branching device 1A according to the present invention is configured so that the driving force from the driving source 150 can be branched and output to a main transmission path including a pump unit and an actuator fluidly connected to each other and a transmission path including a PTO unit. Has been.
In the present embodiment, a case where first and second hydraulic motor units configured to be able to drive a pair of drive wheels, respectively, will be described as an example of the actuator.
[0019]
FIGS. 1A and 1B show a side view and a plan view of a lawn mower 100 to which a power split device 1A according to the present embodiment is applied. FIG. 2 shows a hydraulic circuit diagram of the lawn mower 100. FIG. 3 is a cross-sectional view taken along line III-III in FIG.
[0020]
First, the lawn mower 100 will be described.
As shown in FIG. 1, the lawn mower 100 includes a body frame 110, a pair of left and right drive wheels (rear wheels in the present embodiment) supported by the body frame 110, and the drive wheels 120. Between the caster 130 supported by the body frame 110 and the drive wheel 120 and the caster 130 so as to be disposed on one side in the vehicle front-rear direction (the front side in the present embodiment). As described above, the ground work machine (more in this embodiment) 140 supported by the body frame 110 and the ground work machine 140 on the opposite side in the vehicle front-rear direction with the drive wheel 120 interposed therebetween. (In the present embodiment, the drive source 150 supported by the body frame 110 and the motor shaft 161 are respectively provided on the pair of left and right drive wheels 120 so as to be located on the rear side). It includes first and second hydraulic motor unit 160a is dynamically linked, and 160 b, and a power-dividing device 1A according to this embodiment.
[0021]
In addition, the code | symbol 145 in FIG. 3 is a duct which forms the discharge path from the said mower 140. FIG. Further, reference numeral 110a in FIGS. 1 and 3 is a reinforcing cross member that is welded and fixed between a pair of left and right main frames constituting the body frame 110.
Reference numerals 165 in FIGS. 2 and 3 denote brake devices that apply a braking force to the motor shafts of the first and second hydraulic motor units, respectively.
[0022]
4 and 5 show a longitudinal side view and a cross-sectional plan view of the power split device 1A according to the present embodiment, respectively.
As shown in FIGS. 4 and 5, the power branching device 1A includes a case member 10, an input shaft 20 supported by the case member 10, a PTO unit 30 accommodated in the case member 10, and the case. A transmission mechanism housed in a member, the transmission mechanism 50 transmitting power from the input shaft to the PTO shaft, a first pump unit 60a supported by the case member 10, and supported by the case member 10. And a second pump unit 60b.
[0023]
As shown in FIGS. 4 and 5, in the present embodiment, the case member 10 has a first case member 11 and a second case member 12 that can be divided along one side and the other side in the vehicle front-rear direction. ing.
[0024]
The input shaft 20 is supported by the case member 10 so that one end 21 (the rear end in the present embodiment) can be operatively connected to the drive source 150. The input shaft 20 is preferably supported by the case member 10 so as to be positioned at substantially the same position in the vertical direction as the output portion of the drive source 150 (see FIG. 1A).
More preferably, the input shaft 20 is located at substantially the same position in the vehicle width direction as the output portion of the drive source 150 (see FIG. 1B).
By providing such a configuration, the output unit of the drive source 150 and the input shaft 20 can be easily connected.
[0025]
In the present embodiment, the drive source 150 is supported in an anti-vibration manner with respect to the body frame 110, and the case member 10 is fixedly supported on the body frame 110.
Therefore, in order to absorb the vibration difference between the input shaft 20 and the drive source 150, the input shaft 20 and the output portion of the drive source 150 are connected via a vibration absorbing transmission means. ing. In the present embodiment, a transmission shaft 80 having universal joints 81 attached to both ends is used as the vibration absorbing transmission means.
[0026]
In the present embodiment, the case member 10 is configured to be fixedly supported on the body frame 110 while being separated from the drive source 150 that is supported by the body frame 110 in an anti-vibration manner. Instead, the case member 10 can be connected to and supported by the drive source 150 in a free state with respect to the body frame 110.
According to such a configuration, a vibration difference between the drive source 150 and the case member 10 can be eliminated.
[0027]
In the present embodiment, the input shaft 20 is supported by the case member 10 along the longitudinal direction of the vehicle, and in addition to the one end 21 that is operatively connected to the drive source 150, the other end 22 is provided. (The front end portion in the present embodiment) also extends outward from the case member 10.
[0028]
A charge pump unit 90 is driven and supported at the other end outward extending portion 22 of the input shaft 20.
The charge pump unit 90 supplies pressure oil to various hydraulic circuits, as will be described later.
In the present embodiment, the charge pump 90 is a trochoid type, but when a high pressure or a high capacity is required, an external gear pump can be used.
[0029]
The PTO unit 30 has a PTO shaft 31 supported by the case member 10 below the input shaft 20.
The PTO shaft 31 has a base end portion (a rear end portion in the present embodiment) positioned in the case member 10 and a free end portion (a front end portion in the present embodiment) at the case member 10. Is supported by the case member 10 so as to extend outward.
In the present embodiment, the outwardly extending portion of the PTO shaft 31 is operatively connected to the input portion of the mower 140 through vibration absorbing transmission means 80 (see FIG. 1).
[0030]
The transmission mechanism 50 is configured to transmit a driving force from the input shaft 20 to the PTO shaft 31 as described above.
In the present embodiment, the transmission mechanism 50 supports a drive side gear 51 supported so as not to rotate relative to the input shaft 20, a counter gear 52 meshing with the drive side gear 51, and the counter gear 52. And a driven side gear 54 that meshes with the counter gear 52 and is configured to transmit rotational power to the PTO shaft 31.
[0031]
FIG. 6 shows a longitudinal rear view of the power split device 1A.
As shown in FIG. 6, in the present embodiment, the input shaft 20 and the PTO shaft 31 are positioned at substantially the same position in the vehicle width direction, and the counter shaft 53 is connected to the input shaft 20 and the PTO shaft 31. It is located at substantially the same position in the vehicle width direction, thereby maximizing the vertical displacement between the input shaft 20 and the PTO shaft 31 and minimizing the length in the vehicle width direction of the power branch device 1A. ing.
[0032]
More preferably, the PTO unit 30 can include a PTO clutch mechanism 40 that selectively engages / disconnects power transmission between the drive-side member 54 and the PTO shaft 31.
That is, the driven gear 54 can be rotated relative to the PTO shaft 31, and the PTO clutch mechanism 40 can be provided between the driven gear 54 and the PTO shaft 31.
[0033]
Specifically, the PTO clutch mechanism 40 is a drive side member 40a supported on the PTO shaft 31 so as to be relatively rotatable and non-slidable in the axial direction, and is a drive side member that rotates integrally with the driven side gear 54. 40a, a drive side friction plate 40b supported by the drive side member 40a so as not to be relatively rotatable and slidable in the axial direction, a driven side member 40c supported so as not to be relatively rotatable on the PTO shaft 31, and the driven side The driven friction plate 40d supported by the member 40c so as not to be relatively rotatable and slidable within a certain range in the axial direction, and the driven friction plate 40d and the drive side friction plate 40b are frictionally engaged with each other under the action of hydraulic pressure. And a clutch urging member 40f for separating the clutch pushing member 40e from the driving side friction plate 40b and the driven side friction plate 40d.
[0034]
As described above, the PTO clutch mechanism 40 rotates integrally with the driven gear 54 and is supported between the drive side member 40 a and the PTO shaft 31 that are rotatably supported by the PTO shaft 31. By configuring so that the power can be shut off at the input shaft 20, the power transmission state from the input shaft 20 to the first and second pump shafts 61 a and 61 b described later is maintained, and the input shaft 20 to the PTO shaft 31 is maintained. Power interruption can be performed.
[0035]
In the PTO clutch mechanism 40 having such a configuration, when the clutch pushing member 40e frictionally engages both the friction plates 40b and 40d by the action of operating hydraulic pressure, the drive side member 40a and the driven side are driven from the input shaft 20. When power is transmitted to the PTO shaft 31 via the member 40c and no hydraulic action is applied, power transmission from the input shaft 20 to the PTO shaft 31 is interrupted.
Note that hydraulic oil to the PTO clutch mechanism can utilize pressure oil from the charge pump (see FIG. 2).
[0036]
Further, preferably, the PTO unit 30 can be provided with a PTO brake mechanism 45 that is interlocked with the clutch operation of the PTO clutch mechanism 40, so that the PTO clutch mechanism 40 is connected when the power is cut off. It is possible to effectively prevent the PTO shaft 31 from continuing to rotate due to the inertial force of the ground work machine 140.
[0037]
The PTO brake mechanism 45 is supported so as not to rotate relative to the PTO shaft 31 and to be axially slidable, and to be non-rotatable and axially slidable so as to face the brake disk 45a. The fixed disk 45b, and the brake pushing member 45c linked to the clutch pushing member 40e through the connecting member 42 are provided.
The brake pushing member 45c is arranged such that when the clutch pushing member 40e is separated from the driving side friction plate 40b and the driven side friction plate 40d by the urging force of the clutch urging member 40f, the brake disc 45a The fixed disk 45b is frictionally engaged, and the clutch pushing member 40e receives the action of hydraulic pressure to resist the urging force of the clutch urging member 40f, thereby causing the driving side friction plate 40b and the driven side friction plate 40d to move. When the friction engagement is performed, the clutch pusher member 40e is linked and linked so as to be separated from the brake disc 45a and the fixed disc 45b.
[0038]
As shown in FIG. 2, the first and second pump units 60a and 60b are respectively connected to the first via a hydraulic circuit (in this embodiment, a pair of hydraulic lines 200a and a pair of hydraulic lines 200b). The hydraulic motor unit 160a and the second hydraulic motor unit 160b are fluidly connected.
That is, in the present embodiment, the first pump unit 60 and the first hydraulic motor unit 160a constitute a first HST, and the second pump unit 60b and the second hydraulic motor unit 160b constitute a second HST. It is composed.
[0039]
The power branching device 1A according to the present embodiment is configured so that each of the pair of left and right hydraulic motor units 160a and 160b can drive the pair of drive wheels 120 of the lawn mower 100 at independent rotation speeds. The first and second pump units 60a and 60b corresponding to the above are provided, but the present invention is not limited to such a form, and an aspect having only one pump unit or an aspect having three or more pump units. Is also included.
For example, when only a single pump unit is provided, the single pump unit is fluidly connected to the pair of left and right hydraulic motor units 160a and 160b via a hydraulic circuit having fluid distribution means such as a diversion valve. Connected.
[0040]
At least one of the pump units 60a and 60b and the hydraulic motor units 160a and 160b that are fluidly connected to constitute the HST is a variable displacement type in which the suction / discharge amount is changed by the operation of the output adjusting member. By controlling the tilt position of the adjusting member, a continuously variable transmission output is obtained from the motor shafts of the hydraulic motor units 160a and 160b. In the present embodiment, the first and second pump units 60a and 60b are variable displacement types, and the first and second hydraulic motor units 160a and 160b are fixed displacement types.
[0041]
Specifically, the first pump unit 60a and the second pump unit 60b are connected to the case member 10 and the first and second pump shafts 61a and 61b operatively connected to the input shaft 20, respectively. The first and second pump cases 62a and 62b, the first and second pump bodies 63a and 63b driven by the first and second pump shafts 61a and 61b, and the first and second pump bodies 63a. , 63b, and first and second center sections 64a, 64b.
[0042]
In the present embodiment, the first and second pump units 60a and 60b are connected to one side and the other side of the case member 10 in the vehicle front-rear direction, respectively.
Specifically, the first pump unit 60a is connected to one side of the case member 10 in the vehicle front-rear direction (the front side in the present embodiment) above the PTO shaft 31.
On the other hand, the second pump unit 60b is disposed below the one end portion (rear end portion in the present embodiment) of the input shaft 20 and on the other side in the vehicle front-rear direction of the case member 10 (rear in the present embodiment). Side).
In this way, the first and second pump units 60a and 60b are distributed in the longitudinal direction of the case member 10 to effectively use the dead space in the vicinity of the input shaft 20 and the PTO shaft 31, and the entire power branching device. Increase in size can be suppressed.
[0043]
Each of the first and second pump shafts 61a and 61b is operatively connected to the input shaft 20 in the case member 10 in a state along the longitudinal direction of the vehicle, and the free end side is The case member 10 is supported so as to be located outward from the case member 10.
Specifically, the counter shaft 53 in the transmission mechanism 50 is not rotatable relative to the counter gear 52, and has an axial hole in which a spline is provided on the inner peripheral surface.
The first and second pump shafts 61 a and 61 b are arranged coaxially with the counter shaft 53, and the base ends of the first and second pump shafts 61 a and 61 b are connected to the inner peripheral spline of the counter shaft 53.
As described above, by arranging the first and second pump shafts 61a and 61b coaxially, power transmission from the input shaft 20 to the first and second pump shafts 61a and 61b can be efficiently performed. Can do.
[0044]
The first and second pump cases 62a and 62b have first and second base end walls having insertion holes through which the first and second pump shafts 61a and 61b are inserted, respectively, and a peripheral portion of the base end wall. The two pump shafts have a peripheral wall extending in the axial direction and having an opening on the free end side, and the base end wall is connected to the case member.
[0045]
The first and second pump bodies 63a and 63b perform a rotational motion around the axis of the corresponding pump shaft as the first and second pump shafts 61a and 61b rotate, and are linked to the rotational motion. The piston units 66a and 66b that reciprocally move, the cylinder units 67a and 67b that reciprocately accommodate the piston units 66a and 66ba and rotate together with the piston units 66a and 66b, and the pistons depending on the tilt position. Output adjustment members 68a and 68b that regulate the stroke length of the units 66a and 66b and change the amount of intake / discharge oil by the piston units 66a and 66ba, and the tilt positions of the output adjustment members 68a and 68b are externally operated. Control shafts 69a and 69b connected to the output adjusting members 68a and 68b so as to obtain Eteiru.
In the present embodiment, the hydraulic pump bodies 63a and 63b are of the axial piston type, but of course may be of a radial piston type.
[0046]
As described above, in the power branching device 1A according to the present embodiment, the first and second pump units 60a and 60b have the same configuration and are connected to the case member 10.
Therefore, a common general-purpose product can be used as the first and second pump units 60a and 60b, and the manufacturing cost can be reduced.
[0047]
Preferably, the first and second hydraulic pump bodies 63a and 63b are connected to the case member 10 so that the control shafts 69a and 69b extend to one side and the other side in the vehicle width direction.
By providing such a configuration, the control shafts 69a and 69b of the first and second hydraulic pump bodies 63a and 63b are connected to the left and right operation levers 19a and 190b (FIG. 1A). ) Can be easily linked to each other.
[0048]
The first and second center sections 64a and 64b are respectively free of the first and second pump cases 62a and 62b in a state where the first and second cylinder blocks 67a and 67b are rotatably supported. It connects with this 1st and 2nd pump case 62a, 62b so that an end side opening may be obstruct | occluded.
[0049]
The first and second center sections 64a and 64b include a pair of first oil passages 210a and a pair of first oil passages 210a that form part of the pair of first hydraulic lines 200a and the pair of second hydraulic lines 200b, respectively. Two oil passages 210b, first and second bypass oil passages 220a and 220b communicating between the pair of first oil passages 210a and the pair of second oil passages 210b, respectively, and the first and second oil passages 210b. Check valves 230a and 230b inserted in the bypass oil passages 220a and 220b, and a charge oil passage forming a charge line from the charge pump 90 to the pair of first oil passages 210a and the pair of second oil passages 210b 240a (see FIG. 2).
[0050]
Preferably, the first and second center sections 64a and 64b are connected to the first and second oil passages 210a and the second oil passages 210b by other bypass oil passages. 250a and 250b can be provided.
By providing such other bypass oil passages 250a and 250b, it is possible to easily obtain a free wheel state when the vehicle is forcibly pulled when the drive source fails.
[0051]
In the present embodiment, the hydraulic motor units 160a and 160b are installed on the upper surface of the reduction gear box 162 so that the motor shaft 161 is orthogonal to the corresponding axle 121, as shown in FIG. This saves space between the fuselage frame 110 and the drive wheels 120.
Specifically, the speed reduction gear box 162 has a surface facing the vehicle width direction inner side fastened to the fuselage frame 110, and a surface facing the vehicle vehicle width direction outer side includes an axle 121 for mounting the drive wheels 120. Protruding / supporting.
The hydraulic motor units 160 a and 160 b are installed in the reduction gear box 162 having such a configuration so that the motor shaft 161 is orthogonal to the axle 120.
In the illustrated embodiment, the hydraulic motor units 160a and 160b are installed on the upper surface of the reduction gear box 162 so that the motor shaft 161 faces the vertical direction. Instead, the reduction gear box 162 is provided. It can also be installed on the front or rear side.
[0052]
In the reduction gear box 162, an intermediate shaft 163 is disposed concentrically with respect to the corresponding axle 121. The intermediate shaft 163 has a large bevel gear 164b that meshes with a small pinion 164a provided on the corresponding motor shaft 161 and converts the rotation of power from the motor shaft 161 in a right angle direction to transmit the reduced speed. It is set up. Further, a planetary gear type reduction gear device 166 is interposed at the abutting portion between the intermediate shaft 163 and the corresponding axle 120.
With this configuration, the power output from the hydraulic motor unit 160 is reduced in two stages as a whole by the reduction gear box 162 to drive the drive wheels 120.
[0053]
Hereinafter, the hydraulic circuit of the power split device 1A according to the present embodiment will be described mainly with reference to FIG.
The charge pump 90 has a suction port fluidly connected to the oil tank 180 via a filter 181, and a discharge port having a first HST hydraulic circuit 300a and a second HST hydraulic circuit 300b, a mower elevating hydraulic circuit 300c, The PTO clutch mechanism hydraulic circuit 300d is fluidly connected.
[0054]
Specifically, a main discharge line 310 having a main relief valve 320 inserted is connected to the discharge port of the charge pump 90.
The mower elevating hydraulic circuit 300c is supplied with hydraulic oil from the primary side of the main relief valve 320.
The first HST hydraulic circuit 300a and the second HST hydraulic circuit 300b are configured such that hydraulic oil is supplied from the secondary side of the main relief valve 320 to the charge line.
The PTO clutch mechanism hydraulic circuit 300d is supplied with hydraulic oil from the drain port of the main relief valve 320.
[0055]
Reference numerals 331 and 332 in FIG. 2 denote a switching valve and an accumulator provided in the PTO clutch mechanism hydraulic circuit 300d, and these are inserted in the thick portion of the case member 10 (FIG. 2). 4).
[0056]
In the power branching apparatus 1A having such a configuration, the following effects can be obtained in addition to the various effects described above.
That is, the power branching device 1A has the PTO shaft 31 disposed below the input shaft 20, and connects the input shaft 20 and the PTO shaft 31 by the transmission mechanism 50. The power is transmitted to the pump shaft 61a and the second pump shaft 61b.
[0057]
In such a configuration, the driving force from the driving source 150 can be reliably and easily branched and output to the main transmission path including the pump units 60 a and 60 b and the sub transmission path including the PTO unit 30.
[0058]
Further, by providing the above configuration, it is possible to suppress vertical displacement between the PTO shaft 31 and the input unit of the ground work machine 140 while suppressing vertical displacement between the input shaft 20 and the output unit of the drive source 150. it can.
Therefore, power transmission between the input shaft 20 and the output unit of the drive source and power transmission between the PTO shaft 31 and the input unit of the ground work machine 140 can be performed without difficulty.
[0059]
Such a point is particularly effective when the PTO shaft 31 is connected to the mower 140 as in the present embodiment.
That is, the mower discharge path generally has a side discharge type shown in FIG. 7 in addition to the center discharge type shown in FIG.
[0060]
These center discharge type or side discharge type are appropriately selected as necessary and / or desired, but usually the height of the input portion of the mower device differs between the two.
As described above, the power branching device 1A according to the present embodiment has the PTO shaft 31 disposed below the input shaft 20, and therefore, the PTO shaft can be used in either the center discharge type or the side discharge type. The vertical displacement between 31 and the mower input portion can be suppressed.
Therefore, it can be effectively applied to either the center discharge type or the side discharge type without requiring additional members or changes.
[0061]
Further, in the present embodiment, the input shaft 20 and the PTO shaft 31 are arranged at substantially the same position in the vehicle width direction as the output portion of the drive source 150 and the input portion of the mower, respectively. And power transmission between these can be performed more simply.
[0062]
In the present embodiment, the counter shaft 53 of the transmission mechanism 50 is positioned at substantially the same position as the input shaft 20 and the PTO shaft 31 in the vehicle width direction. However, the present invention naturally has such a configuration. It is not limited to.
For example, as shown in FIG. 8A, the counter shaft 53 can be displaced to one side in the vehicle width direction with respect to the input shaft 20 and the PTO shaft 31.
[0063]
Furthermore, in the present embodiment, the first pump unit 60a and the second pump unit 60b are distributed to one side and the other side of the case member 10 in the vehicle front-rear direction, as shown in FIG. The first and second pump units 60a and 60b may be connected to the same side of the case member 10 in the vehicle front-rear direction. 6 and 8 (a) and 8 (b), the input shaft 20, the first and second pump shafts 61a and 61b, and the PTO shaft 31 form a serial relationship with respect to the transmission direction. However, instead of this, the transmission path from the input shaft 20 to the pump shafts 61a and 61b and the transmission path from the input shaft 20 to the PTO shaft 31 can be configured in parallel. (See FIG. 9). Of course, when the transmission path from the input shaft 20 to the pump shaft 61 and the power path from the input shaft 20 to the PTO shaft 31 are configured in parallel, the first and second hydraulic pump units 60a and 60b are provided. It is also possible to distribute and arrange the case member 10 on one side and the other side in the vehicle front-rear direction.
[0064]
Furthermore, in the present embodiment, the first and second pump units 60a and 60b are configured to be connected to the case member 10, but instead of the first and second pump unit main bodies 63a, It is also possible to accommodate 63b in the case member 10.
[0065]
In the present embodiment, the charge pump 90 is driven by the input shaft 20, but instead, any one of the first and second pump units 60a, 60b is connected to the pump shaft. The length is projected outward from the corresponding center section 64a, 64b, and the charge pump 90 is attached to the center section so as to cover the projecting end, and the charge pump 90 is driven by the projecting end. It is also possible.
In such a replacement mode, the first and second pump units 60a and 60b cannot have the same configuration, but the charge oil passage in the center section on the side where the charge pump is installed is connected to the charge oil passage from the charge pump without piping. Pressure oil can be supplied, thereby eliminating the need for charge line piping.
[0066]
【The invention's effect】
According to the power branching apparatus according to the present invention, the driving force from the drive source can be easily branched into the main power transmission path including the pump shaft and the sub power transmission path including the PTO shaft.
In addition, when the output from the PTO shaft is input to the ground work machine, the vertical displacement between the PTO shaft and the input part of the ground work machine is suppressed while suppressing the vertical displacement between the output part of the drive source and the input shaft. Can do. Therefore, power transmission between the drive source and the input shaft and between the PTO shaft and the ground work machine can be performed without difficulty.
[0067]
Furthermore, in the aspect including the first and second pump units, if the first and second pump units have the same components, general-purpose products can be used for the first and second pump units. .
Further, if the first and second pump units are connected to one side and the other side of the case member in the vehicle front-rear direction, the dead space near the case member can be effectively used.
[0068]
Furthermore, if a charge pump unit operatively connected to the input shaft is provided, it is possible to efficiently obtain hydraulic oil for various hydraulic devices.
[Brief description of the drawings]
FIGS. 1 (a) and 1 (b) are a side view and a plan view of a center discharge type lawn mower to which a power branching device according to a preferred embodiment of the present invention is applied.
FIG. 2 is a hydraulic circuit diagram of the lawn mower shown in FIG.
FIG. 3 is a cross-sectional view taken along line III-III in FIG.
FIG. 4 is a longitudinal side view of a power split device according to an embodiment of the present invention.
FIG. 5 is a cross-sectional plan view of the power split device shown in FIG. 4;
6 is a longitudinal rear view of the power split device shown in FIGS. 4 and 5. FIG.
FIGS. 7A and 7B are a side view and a plan view, respectively, of a side discharge type lawn mower to which a power branching device according to an embodiment of the present invention is applied.
FIGS. 8A and 8B are rear views of a power branch device according to another embodiment of the present invention, respectively.
FIG. 9 is a rear view of a power branching apparatus according to still another embodiment of the present invention.
[Explanation of symbols]
1A Power branching device
10 Case member
20 Input shaft
30 PTO unit
31 PTO axis
40 PTO clutch mechanism
45 PTO brake mechanism
50 Transmission mechanism
60a, 60b first and second pump units
61a, 61b first and second pump shafts
62a, 62b first and second pump cases
63a, 63b first and second pump bodies
64a, 64b first and second center sections
90 charge pump
100 lawn mower
120 drive wheels
140 Ground work machine
160a, 160b first and second motor units

Claims (17)

A case member;
An input shaft supported by the case member such that one end can be operatively connected to a drive source;
A PTO unit having a PTO shaft supported by the case member below the input shaft;
A transmission mechanism housed in the case member, the transmission mechanism transmitting power from the input shaft to the PTO shaft;
A first pump unit having a first pump shaft operatively connected to the input shaft, the first pump unit being fluidly connected to an externally disposed actuator. Power branching device for work vehicles. 2. The power branching device for a working vehicle according to claim 1, wherein the first pump shaft is operatively connected to the input shaft via the transmission mechanism. The power branching device for a working vehicle according to claim 2, wherein the first pump shaft is disposed between the input shaft and the PTO shaft in the vertical direction. A second pump unit having a second pump shaft operatively connected to the input shaft, the second pump unit being fluidly connected to an externally disposed actuator; A power branching device for a working vehicle according to any one of claims 1 to 3. 5. The power branching device for a working vehicle according to claim 4, wherein the second pump shaft is operatively connected to the input shaft via the transmission mechanism. 6. 6. The power branching device for a working vehicle according to claim 4, wherein each of the first and second pump units has the same component. The input shaft is along the longitudinal direction of the vehicle,
The power branching device for a work vehicle according to any one of claims 4 to 6, wherein the first pump unit and the second pump unit are connected to the same side of the case member in the vehicle front-rear direction. The input shaft is along the longitudinal direction of the vehicle,
The working vehicle according to any one of claims 4 to 6, wherein the first pump unit and the second pump unit are respectively connected to one side and the other side of the case member in the vehicle front-rear direction. Power branching device. 9. The power branching device for a working vehicle according to claim 8, wherein the first and second pump shafts are coaxially positioned. The first pump unit and the second pump unit are respectively
A base end wall having an insertion hole through which the first and second pump shafts are inserted, and a peripheral wall extending from the peripheral edge of the base end wall in the first and second pump shaft directions and having an open end on the free end side; First and second pump cases in which the base wall is connected to the case member;
First and second pump bodies driven by the first and second pump shafts, and are accommodated in the first and second pump cases from the free end side openings of the first and second pump cases. First and second pump bodies;
First and second center sections connected to the first and second pump cases so as to support the first and second pump bodies and close the free end side openings of the first and second pump cases. The power branching device for a working vehicle according to any one of claims 4 to 9, characterized by comprising: The working vehicle includes a pair of left and right drive wheels and a ground work machine,
The power branch device is disposed between the drive source and the ground work machine in the vehicle longitudinal direction,
The input shaft is operatively connected to the output of the drive source, and the PTO shaft is operatively connected to the ground work machine;
The working vehicle according to claim 4, wherein the first and second pump units are fluidly connected to a pair of left and right hydraulic motor units that drive each of the pair of drive wheels. Power branching device. The power branching device for a working vehicle according to any one of claims 1 to 10, further comprising a charge pump unit operatively connected to the input shaft. 13. The PTO unit according to claim 1, further comprising a PTO clutch mechanism that selectively engages / disconnects power transmission from the input shaft to the PTO shaft. Power vehicle branching device. The PTO unit further includes a PTO brake mechanism that releases / adds a braking force to the PTO shaft in conjunction with a power transmission / cut-off operation from the input shaft to the PTO shaft by the PTO clutch mechanism. The power branching device for a working vehicle according to claim 13. 15. The PTO clutch mechanism and / or the PTO brake mechanism is supplied with a part of pressure oil from a charge pump unit operatively driven by the input shaft as hydraulic oil. A power branching device for a working vehicle according to claim 1. The power of the working vehicle according to any one of claims 1 to 15, wherein the input shaft and the PTO shaft are along a longitudinal direction of the vehicle and are located at substantially the same position in the vehicle width direction. Branch device. A case member;
An input shaft supported by the case member such that one end can be operatively connected to a drive source;
A PTO shaft supported by the case member below the input shaft;
A transmission mechanism housed in the case member, the transmission mechanism transmitting power from the input shaft to the PTO shaft;
A first pump shaft operatively coupled to the input shaft;
A first pump unit main body housed in the case member and driven by the first pump shaft, wherein the first pump unit main body is fluidly connected to an externally disposed actuator. A working vehicle power branching device.

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