JP2007024222A - Transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maximize a free space above a differential gear mechanism without increasing the size of a transmission case in a transmission comprising a traveling transmission mechanism having an HST, a planetary gear mechanism, a traveling gear transmission mechanism, and a differential gear mechanism and a PTO transmission mechanism having a PTO clutch mechanism. <P>SOLUTION: The HST is connected to the first end wall of the transmission case in the longitudinal one direction of a vehicle. The planetary gear mechanism, the traveling gear transmission mechanism, and the PTO clutch mechanism are stored in the transmission case so as to be positioned between the first end wall and the differential gear mechanism in the longitudinal direction of the vehicle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transmission applied to a work vehicle such as a tractor.

In a vehicle transmission having a traveling system transmission mechanism that transmits power from a driving source to a pair of left and right main drive wheels, and a PTO system transmission mechanism that transmits power from the driving source to a PTO shaft, the traveling system transmission mechanism HST operatively connected to the drive source, a planetary gear mechanism for inputting constant speed power and variable speed power from the pump shaft and motor shaft of the HST, and a traveling system gear shift for inputting the output of the planetary gear mechanism, respectively. It has been conventionally known that a mechanism and a differential gear mechanism disposed downstream of the traveling gear transmission mechanism are known (for example, see Patent Document 1 below).
Such a transmission is effective in terms of transmission efficiency because a part of the power transmitted by the traveling system transmission mechanism is not converted into hydraulic pressure.

However, the conventional transmission has room for improvement from the viewpoint of compactly arranging the traveling transmission mechanism and the PTO transmission mechanism.
That is, in the conventional transmission, power is transmitted to the differential gear mechanism from the other side in the vehicle front-rear direction while the HST is disposed on one side in the vehicle front-rear direction with respect to the differential gear mechanism. Yes.
In such a configuration, a plurality of traveling system rotation shafts and PTO system rotation shafts extending in the vehicle front-rear direction are disposed above the differential gear mechanism, and the brakes are disposed along the vehicle width direction. Installation of the operation shaft and differential lock operation shaft becomes difficult.
JP 2003-207021 A

  The present invention has been made in view of the prior art, and includes a traveling system transmission mechanism including an HST, a planetary gear mechanism, a traveling system gear transmission mechanism, and a differential gear mechanism, and a PTO transmission mechanism including a PTO clutch mechanism. An object of the present invention is to provide a transmission that can secure as much free space as possible above the differential gear mechanism without increasing the size of the transmission case.

  In order to achieve the above object, the present invention provides a planetary gear for inputting power from a drive source, HST operatively connected to the drive source, and constant speed power and variable speed power from a pump shaft and a motor shaft of the HST, respectively. A pair of left and right main drive wheels via a traveling system transmission mechanism including a mechanism, a traveling system gear transmission mechanism for inputting the output of the planetary gear mechanism, and a differential gear mechanism disposed downstream of the traveling system gear transmission mechanism Of the vehicle configured to be capable of transmitting the power from the drive source to the outside via a PTO transmission mechanism including a PTO clutch mechanism disposed downstream of the HST pump shaft. A transmission comprising the planetary gear mechanism, the traveling gear transmission mechanism, the differential gear mechanism, and the PTO clutch mechanism. The HST is connected to a first end wall on one side of the transmission case in the vehicle front-rear direction, and the planetary gear mechanism, the traveling gear transmission mechanism, and the PTO clutch mechanism are A vehicle transmission housed in the transmission case is provided so as to be positioned between the first end wall and the differential gear mechanism with respect to a direction.

Preferably, the transmission case includes a peripheral wall, the first end wall extending in a substantially vertical direction at one end of the peripheral wall in the vehicle front-rear direction, and a substantially vertical direction in the end of the peripheral wall on the other side in the vehicle front-rear direction. A second end wall extending in a vertical direction and an intermediate wall extending in a substantially vertical direction between the first and second end walls.
In this aspect, the planetary gear mechanism, the traveling gear transmission mechanism, and the PTO clutch mechanism are accommodated in a first space defined by the first end wall and the intermediate wall, and the differential The gear mechanism is accommodated in a second space defined by the intermediate wall and the second end wall.

In one aspect, the PTO transmission mechanism further includes a PTO gear transmission mechanism.
The PTO gear transmission mechanism is accommodated in the first space.

In the various aspects, preferably, the mission case may include a first portion having the first end wall and a second portion having the intermediate wall and the second end wall.
The first and second parts are detachably connected.

As described above, in the present invention, the HST is connected to the first end wall on one side of the transmission case in the vehicle longitudinal direction, and the planetary gear mechanism, the traveling system gear transmission mechanism, and the PTO system clutch mechanism are connected in the vehicle longitudinal direction. It is accommodated in the transmission case between the first end wall and the differential gear mechanism.
According to the present invention, a traveling system rotating shaft and a PTO system rotating shaft are not disposed above the differential gear mechanism, and as much free space as possible is secured above the differential gear mechanism. Can do.
Therefore, the brake operation shaft and the diff lock operation shaft disposed along the vehicle width direction can be easily installed above the differential gear mechanism, and the transmission case can be downsized in the vertical direction.

Hereinafter, preferred embodiments of a transmission according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a partial perspective view of a working vehicle 1 to which a transmission 100 according to the present embodiment is applied. FIG. 2 shows a schematic diagram of transmission of the working vehicle 1.

  As shown in FIGS. 1 and 2, the working vehicle 1 includes a vehicle frame 10 (see FIG. 1) extending in the longitudinal direction of the vehicle and one end side (front side in the illustrated embodiment) of the vehicle frame 10 in the longitudinal direction of the vehicle. A supported drive source 20 (see FIG. 2) and a vehicle frame 10 at the other end in the vehicle longitudinal direction (a rear side in the illustrated embodiment) at a position spaced from the drive source 20 in the vehicle longitudinal direction. The transmission 100 is provided.

  The transmission 100 includes a travel transmission mechanism that transmits power input from the drive source 20 via a transmission shaft 25 (see FIG. 2) to main drive wheels (rear wheels 30 in the illustrated form), And a PTO transmission mechanism that outputs power from the drive source 20 to the outside.

  Specifically, as shown in FIG. 2, the transmission 100 includes an HST 110 operatively connected to the drive source 20, a planetary gear mechanism 120 disposed downstream in the transmission direction of the HST 110, and the planetary gear mechanism 120. A traveling gear transmission mechanism 130 disposed downstream in the transmission direction, a differential gear mechanism 140 disposed downstream in the transmission direction of the traveling gear transmission mechanism 130, and a downstream transmission direction of the HST 110. A PTO clutch mechanism 210 provided; a PTO gear transmission mechanism 220 disposed downstream in the transmission direction of the PTO clutch mechanism 210; and a main PTO shaft 540 operatively connected to the PTO gear transmission mechanism 220. The HST 110, the planetary gear mechanism 120, the traveling system gear transmission mechanism 130, and the Fan Ren Shall gear mechanism 140 forming the traveling transmission mechanism, and, the PTO clutch mechanism 210 and the PTO gear speed change mechanism 220 forms the PTO system transmission mechanism.

3 to 5 are a perspective view, a front view, and a rear view of the transmission 100, respectively.
As shown in FIGS. 3 to 5, the transmission 100 includes a transmission case 300 that supports or accommodates the various transmission mechanisms in addition to the above configuration.
Specifically, the transmission case 300 accommodates the planetary gear mechanism 120, the traveling gear transmission mechanism 130, the differential gear mechanism 140, the PTO clutch mechanism 210, and the PTO gear transmission mechanism 220, and the longitudinal direction of the vehicle. The HST 110 is supported on the outer surface of the first end wall 301 (the front wall in the present embodiment) on one end side in the direction.

FIG. 6 is an exploded perspective view of the mission case 300.
7 to 9 are a left side view, a right side view, and a plan view of the transmission mechanism in the transmission 100, respectively. 7 to 9, the mission case 300 is indicated by a broken line.
As shown in FIGS. 3 to 9, the transmission case 300 includes a peripheral wall 305, a first end wall 301 extending in a substantially vertical direction at an end of the peripheral wall 305 on one side in the vehicle front-rear direction, and the peripheral wall 305. A second end wall 302 extending in a substantially vertical direction at an end on the other side in the vehicle front-rear direction and an intermediate wall 303 extending in a substantially vertical direction between the first and second end walls 301 and 302 are provided.

As shown in FIGS. 7 to 9, the transmission case 300 includes the planetary gear mechanism 120 and the traveling system gear shift in a first space 300 a defined by the first end wall 301 and the intermediate wall 303. The differential gear mechanism 140 is accommodated in the second space 300b that houses the mechanism 130, the PTO clutch mechanism 210, and the PTO gear transmission mechanism 220, and is defined by the intermediate wall 303 and the second end wall 302. Is housed.
The HST 110 is connected to the outer surface of the first end wall 301 of the mission case 300 as described above (see FIG. 3).

6, the transmission case 300 includes a case body 320 having the intermediate wall 303 and the second end wall 302, and a lid member 310 having the first end wall 301, A lid member 310 detachably coupled to the case body 320 can be provided.
As described above, the transmission case 300 is formed by the case main body 320 and the lid member 310 that are separably connected to each other, so that the transmission mechanism can be easily installed in the first space 300a. it can.

10 and 11 show a perspective view and a front view of the transmission 100 with the lid member 310 removed, respectively.
FIG. 12 is a perspective view of the transmission 100 with the transmission case 300 removed.
Further, FIG. 13 shows a partially developed cross-sectional view of the transmission 300.

  As shown in FIGS. 2 and 13, the HST 110 includes a pump shaft 111 that is operatively connected to the drive source 20, a pump main body 112 that is supported by the pump shaft 111 so as not to rotate relative thereto, and the pump main body 112. The motor main body 114 fluidly connected to the motor main body 114 through a pair of hydraulic oil passages, the motor shaft 113 that supports the motor main body 114 so as not to be relatively rotatable, and the supply / discharge oil amount of the pump main body 112 or the motor main body 114 are changed. An output adjustment member 115 for controlling the rotation of the motor shaft (HST output shaft) 113 with respect to the rotation speed of the pump shaft (HST input shaft) 111 by operating the output adjustment member 115. It can be shifted.

  As shown in FIG. 13, the HST 110 has a downstream end portion in the transmission direction of the pump shaft 111 and the motor shaft 113 (a rear end portion in the present embodiment) penetrating through the first end wall 301. The first end wall 301 is supported so as to enter the first space 300a.

  In the planetary gear mechanism 120, the first element among the three planetary elements including the sun gear 121, the planet carrier 122, and the internal gear 123 functions as a constant speed input unit that inputs constant speed rotational power from the pump shaft 111. The second element of the three planetary elements acts as a variable input unit for inputting variable rotational power from the motor shaft 113, and the third element of the three planetary elements is the constant speed input unit and It is comprised so that it may act as an output part which synthesize | combines and outputs the rotational power of the said variable input part.

In the present embodiment, as shown in FIGS. 2, 11 and 13, the planetary gear mechanism 120 is disposed concentrically with the motor shaft 113.
The sun gear 121 acts as the variable input portion operatively connected to the motor shaft 113, the planet carrier 122 acts as the constant speed input portion operatively connected to the pump shaft 111, and the internal gear 123. Serves as the output section.

Preferably, when the HST 110 is in the maximum output state in the reverse rotation direction, the output portion of the planetary gear mechanism 120 becomes zero output, and when the HST 110 is in the zero output state (neutral state), the output of the planetary gear mechanism 120 The gear ratio of the planetary gear mechanism 120 can be set so that the part is in the maximum output state.
By providing such a configuration, it is possible to improve the transmission efficiency of the HST and reduce the load.

Here, the traveling system rotating shaft in the traveling system transmission mechanism will be described.
The traveling system transmission mechanism includes a plurality of traveling system rotations arranged along the longitudinal direction of the vehicle in order to operatively connect the planetary gear mechanism 120, the traveling system gear transmission mechanism 130, and the differential gear mechanism 140. Has an axis.

  Specifically, as shown in FIGS. 2 and 11 and the like, the traveling system rotation shaft is connected to the output portion of the planetary gear mechanism 120 (in this embodiment, the internal gear 123), and the planetary output is connected. A planet output shaft 410 disposed coaxially with the motor shaft 113, a travel system transmission shaft 420 displaced to one side in the vehicle width direction from the planet output shaft 410, and the travel system transmission shaft. And a traveling system transmission shaft 430 disposed below 420.

As shown in FIGS. 2 and 13, the traveling system transmission shaft 420 is operatively connected to the planetary output shaft 410 via a gear train.
The traveling system transmission shaft 430 is operatively connected to the traveling system transmission shaft 420 via the traveling system gear transmission mechanism 130.
That is, the traveling system gear transmission mechanism 130 is configured to perform a multi-stage transmission between the traveling system transmission shaft 420 and the traveling system transmission shaft 430.

Preferably, the traveling system gear transmission mechanism 130 is configured to be able to switch the transmission direction from the traveling system transmission shaft 420 to the traveling system transmission shaft 430.
In this embodiment, as shown in FIGS. 2 and 13, the transmission 100 further serves as the traveling system rotation shaft via a transmission path from the traveling system transmission shaft 420 to the traveling system transmission shaft 430. A traveling system idle shaft 440 is inserted.
10 to 12, the traveling system idle shaft 440 is positioned between the traveling system transmission shaft 420 and the traveling system transmission shaft 430 with respect to the vertical position, and the traveling system with respect to the vehicle width direction position. It is located on one side in the vehicle width direction from the transmission shaft 420 and the traveling system transmission shaft 430.

The traveling system gear transmission mechanism 130 includes a forward transmission mode in which power is transmitted from the traveling system transmission shaft 420 to the traveling system transmission shaft 430 without passing through the traveling system idle shaft 440, and the traveling system transmission shaft 420. To a reverse transmission mode in which power is transmitted to the traveling system transmission shaft 430 via the traveling system idle shaft 440.
In the present embodiment, as shown in FIG. 2, the traveling gear transmission mechanism 430 is configured to perform a two-stage transmission in the forward transmission mode.

The traveling system transmission shaft 430 is configured to transmit the rotational power that has been shifted or reversed through the traveling system gear transmission mechanism 130 to the input ring gear 141 of the differential gear mechanism 140.
In the present embodiment, as shown in FIG. 7, the traveling system transmission shaft 430 is disposed at substantially the same height as the pair of differential output shafts 142 in the differential gear mechanism 140, It is operatively connected to the input ring gear 141 from the side.

In the present embodiment, the traveling system transmission mechanism applies the rotational power of the traveling system transmission shaft 430 to the main driving wheel (rear wheel 30 in the present embodiment), and the auxiliary driving wheel (this embodiment). In the form, it is comprised so that it can output toward the front wheel 40 (refer FIG. 2).
Specifically, the transmission 100 further includes a sub traveling system output shaft 450 that is operatively connected to the traveling system transmission shaft 430 and protrudes outward from the first end wall 301 as the traveling system rotating shaft. is doing.
In the present embodiment, as shown in FIGS. 10 and 11, the sub-travel system output shaft 450 is disposed below the travel system speed change shaft 430.

Preferably, as shown in FIGS. 2 and 13, the traveling transmission mechanism can include a sub drive wheel speed increasing mechanism 150.
By providing such a sub-drive wheel speed increasing mechanism 150, the front wheels can be rotated at a higher speed in order to compensate for the turning radius difference between the front wheels and the rear wheels that occurs when the work vehicle turns.

Next, the PTO system rotation shaft in the PTO system transmission mechanism will be described.
The PTO transmission mechanism includes a plurality of PTO transmission mechanisms arranged in the longitudinal direction of the vehicle in order to output the power from the drive source 20 to the outside via the PTO clutch mechanism 210 and the PTO gear transmission mechanism 220. It has a PTO system rotation axis.

  Specifically, as shown in FIGS. 2, 11, 13, and the like, the PTO rotation shaft includes a PTO input shaft 510 that is coaxial with the pump shaft 111 and is not rotatable about the axis, and the PTO rotation shaft. A PTO clutch shaft 520 disposed below the system input shaft 510 and on the other side in the vehicle width direction; a PTO transmission shaft 530 disposed below the PTO clutch shaft 520; and the PTO transmission shaft 530 A main PTO shaft 540 supported by the second end wall 302 so as to protrude outward from the second end wall 302 of the transmission case 300 in a state of being operatively connected.

As shown in FIGS. 2 and 13, the PTO clutch shaft 520 is operatively connected to the PTO input shaft 510 via the PTO clutch mechanism 210.
In other words, the PTO clutch mechanism 210 is configured to selectively engage or shut off power transmission between the PTO input shaft 510 and the PTO clutch shaft 520.

The PTO transmission shaft 530 is operatively connected to the PTO clutch shaft 520 via the PTO gear transmission mechanism 220.
That is, the PTO gear transmission mechanism 220 is configured to perform multi-stage transmission between the PTO clutch shaft 520 and the PTO transmission shaft 530.

Preferably, the PTO gear transmission mechanism 220 is configured to be able to switch the transmission direction from the PTO clutch shaft 520 to the PTO transmission shaft 530.
In the present embodiment, as shown in FIGS. 2 and 13, the transmission 100 is further connected to the PTO system rotation shaft via a transmission path from the PTO system clutch shaft 520 to the PTO system transmission shaft 530. A PTO idle shaft 550 is inserted.
As shown in FIGS. 10 to 12, the PTO idle shaft 550 is disposed below the PTO clutch shaft 520 and on the other side in the vehicle width direction from the PTO transmission shaft 530.

The PTO gear transmission mechanism 220 includes a forward transmission mode in which power is transmitted from the PTO clutch shaft 520 to the PTO transmission shaft 530 via the PTO idle shaft 550, and the PTO clutch shaft 520. It is configured to have a reverse transmission mode in which power is transmitted to the PTO transmission shaft 530 without passing through the PTO idle shaft 550.
In the present embodiment, as shown in FIG. 2, the PTO gear transmission mechanism 220 is configured to perform a two-speed transmission in the forward rotation transmission mode.

The main PTO shaft 540 is configured to output the rotational power of the PTO transmission shaft 530 to the outside.
In the present embodiment, as shown in FIGS. 2, 7, 8, and 13, the PTO transmission mechanism has an axis line concentrically with the PTO transmission shaft 530 as the PTO rotation shaft. A main PTO transmission shaft 560 is connected so as not to rotate around and rotate.

Specifically, as shown in FIGS. 7 and 8, the main PTO transmission shaft 560 is disposed below the pair of differential output shafts 142 in the differential gear mechanism 140 so as to straddle the differential gear mechanism 140 in the vehicle longitudinal direction. It extends to.
More specifically, as shown in FIGS. 2, 7 and 8, the transmission 100 according to the present embodiment is positioned below a pair of differential output shafts 142 in the differential gear mechanism 140 in addition to the above configuration. A pair of drive axles 160 are provided that are operatively connected to the pair of differential output shafts 142 via a reduction gear train 170, respectively.
The main PTO transmission shaft 560 is disposed concentrically with the PTO transmission shaft 530 so as to straddle the differential gear mechanism 140 using the space between the pair of drive axles 160.
In the present embodiment, the main PTO shaft 540 is connected to the downstream end portion in the transmission direction of the main PTO transmission shaft 560 via a gear train.

By the way, as described above, the transmission 100 according to the present embodiment has the main PTO shaft 540 that protrudes outward from the second end wall 302 as a PTO shaft that outputs the rotational power from the drive source 20 to the outside. Have only.
However, depending on the specifications, it may be necessary to take out rotational power from the first end wall 301 on the opposite side of the second end wall 302 with respect to the mission case 300.
For example, when the transmission 100 according to the present embodiment is disposed on the rear side of the vehicle frame 30 so as to be applied to a working vehicle having a mid-mount mower, the transmission 100 also rotates from the first end wall 301. It is necessary to output power.

In FIG. 14, in addition to the main PTO shaft 540 provided on the second end wall 302, a transmission model of a vehicle provided with a transmission 100 ′ when the sub PTO shaft 570 is provided on the first end wall 301. The figure is shown.
In addition, in the transmission 100 ′ shown in FIG. 14, the planetary gear mechanism 120 is deleted in order to reduce the cost, and the HST 110 is configured to switch between the forward direction and the reverse direction.
Further, in the transmission 100 ′, the sub drive wheel speed increasing mechanism 150 is also omitted.

The transmission 100 according to the present embodiment has the following configuration so that the specification shown in FIG. 2 and the specification shown in FIG. 14 can be easily changed.
That is, the transmission case 300 can support the sub-PTO shaft 570 (see FIG. 14) that is operatively connected to the PTO transmission shaft 530 in place of the PTO idle shaft 550 (see FIG. 2). It is configured.
That is, in the transmission 100 according to the present embodiment, the transmission case 300 is operatively connected to the PTO idle shaft 550 or the PTO transmission shaft 530 that constitutes a part of the PTO gear transmission mechanism 220. The PTO shaft 570 is configured to be selectively mounted.

Preferably, as shown in FIGS. 6 and 13, a portion of the first end wall 301 that supports the PTO idle shaft 550 or the sub PTO shaft 570 enters the first space 300 a from the outside. An access opening 305 that allows access to
With this configuration, when the PTO idle shaft 550 is mounted, the access opening 305 is closed with a cap 306 (see FIGS. 4 and 13), and the sub PTO shaft 570 is mounted. In this case, the specification can be changed without removing the mission case 300 simply by removing the cap 306.

In the aspect including the sub PTO shaft 570, preferably, as shown in FIG. 14, the sub PTO shaft 570 can be provided with a sub PTO shaft clutch mechanism 230.
By providing the sub-PTO shaft clutch mechanism 230, only the main PTO shaft 540 is switched in addition to the integral output state or non-output state of the main PTO shaft 540 and the sub PTO shaft 570 by the PTO clutch mechanism 210. The output state can be realized.

  In addition to the above configuration, the transmission 100 according to the present embodiment further includes an auxiliary pump unit 600 that can discharge pressure oil, and an auxiliary pump system transmission that transmits power from the drive source 20 to the auxiliary pump unit 600. Mechanism.

  The auxiliary pump unit is supported on the outer surface of the second end wall 302 of the mission case 300 as shown in FIGS. 2, 5, 7 and 8.

The auxiliary pump transmission mechanism includes an auxiliary pump transmission shaft 650 that transmits the rotational power of the PTO input shaft 510 to the auxiliary pump unit 600, as shown in FIGS.
In the present embodiment, the auxiliary pump transmission shaft 650 is connected to the PTO system input via the drive side member of the PTO system clutch mechanism 210 supported by the PTO system clutch shaft 520, as shown in FIG. The shaft 510 is operatively connected.

  In the present embodiment, as shown in FIG. 11, the auxiliary pump transmission shaft 650 is on the other side in the vehicle width direction from the virtual vertical plane passing through the axes of the pump shaft 111 and the motor shaft 113, and It is positioned above the PTO system clutch shaft 520, thereby utilizing the space above the pair of differential output shafts 142 at a position avoiding the differential gear mechanism 140 on the other side in the vehicle width direction, The power can be transmitted to the auxiliary pump unit 600 by extending in the vehicle longitudinal direction in the second space 300b.

FIG. 15 shows a hydraulic circuit diagram in the working vehicle 1.
As shown in FIG. 15, the pressure oil from the auxiliary pump unit 600 is supplied to the power steering mechanism hydraulic circuit 700, the PTO clutch mechanism hydraulic circuit 710, and the HST charge hydraulic circuit 720 via a diversion valve 630. The hydraulic circuit connected in series, and the hydraulic circuit for horizontal control of the attached working machine 730 and the hydraulic circuit for hydraulic lift mechanism 740 are respectively supplied to the hydraulic circuit connected in series.
In addition, the code | symbol 750 in FIG. 15 is an external extraction hydraulic circuit.

In the transmission 100 according to the present embodiment, as shown in FIG. 15, the transmission case 300 is used as an oil source for the auxiliary pump unit 600.
That is, the mission case 300 can store oil, thereby eliminating the need for a separate oil tank or reducing the size of the oil tank.

Specifically, the auxiliary pump unit 600 sucks the stored oil in the transmission case 300 through the suction filter 620.
Preferably, as shown in FIG. 4, the suction filter 620 includes the sub-travel system output shaft 450 and the PTO system idle so that at least a part of the position in the vehicle width direction overlaps the HST 110 in a plan view. Positioned between the shafts 550 (or the sub-PTO shaft 570) and at least a part of the vertical position in the side view is the sub-travel system output shaft 450 and the PTO system idle shaft 550 (or the sub-PTO shaft). 570) and the first end wall 301 at a position below the HST 110 so as to overlap.

  By providing such a configuration, the HST 110, the suction filter 620, and the sub traveling system output shaft 450 (and the sub PTO shaft 570) protruding outward from the first end wall 301 of the mission case 300 are Therefore, the transmission case 300 is operatively connected to the pump shaft 111 of the HST 110 and the sub-travel system output shaft 450 (and the sub-PTO shaft 570) without increasing the size of the transmission case 300. The interference between the transmission shaft and the pipe connected to the suction filter 620 can be effectively prevented.

The transmission 100 having such a configuration has the following effects in addition to the various effects described above.
That is, in the transmission 100, the planetary gear mechanism 120, the traveling system gear transmission mechanism 130, the PTO system clutch mechanism 210, and the PTO system gear transmission mechanism 220 are connected to the first end wall 301 with respect to the vehicle longitudinal direction. It is disposed between the differential gear mechanism 140 and a free space can be secured above the differential gear mechanism 140 as much as possible.
Therefore, the brake operation shaft and the diff lock operation shaft arranged along the vehicle width direction can be installed relatively freely.
Further, according to such a configuration, the mission case 300 can be reduced in size in the vertical direction, and accordingly, the height of the driver's seat 50 (see FIG. 1) installed above the mission case 300 is lowered. Thus, getting on and off can be facilitated.

Furthermore, in the transmission 100 according to the present embodiment, as shown in FIG. 11 and the like, all the traveling system rotation shafts are concentric with the motor shaft 113 or on one side in the vehicle width direction from the motor shaft 113. The PTO system rotation shafts are all arranged concentrically with the pump shaft 111 or below the pump shaft 111.
Accordingly, the traveling system transmission mechanism supported by the traveling system rotation shaft and the PTO transmission mechanism supported by the PTO system rotation shaft can be arranged in a unified manner, thereby reducing the size of the mission case 300. Can be achieved.

In the present embodiment, the case where a PTO gear transmission mechanism is provided in the PTO transmission path has been described as an example. However, the PTO gear transmission mechanism may be deleted.
When the PTO gear transmission mechanism is not required, the PTO transmission shaft is also deleted, and the main PTO shaft transmission shaft is operatively connected to the PTO clutch shaft.
Accordingly, in such a configuration, when the sub PTO shaft is provided, the sub PTO shaft is operatively connected to the main PTO shaft transmission shaft.

FIG. 1 is a partial perspective view of a working vehicle to which an embodiment of a transmission according to the present invention is applied. FIG. 2 is a schematic diagram of transmission of the working vehicle shown in FIG. FIG. 3 is a perspective view of a transmission according to an embodiment of the present invention. FIG. 4 is a front view of the transmission shown in FIG. FIG. 5 is a rear view of the transmission shown in FIGS. 3 and 4. FIG. 6 is an exploded perspective view of the transmission case in the transmission shown in FIGS. FIG. 7 is a left side view of the transmission mechanism in the transmission shown in FIGS. 3 to 5, and the transmission case is indicated by a broken line. FIG. 8 is a right side view of the transmission mechanism in the transmission shown in FIGS. 3 to 5, and the transmission case is indicated by a broken line. FIG. 9 is a plan view of a transmission mechanism in the transmission shown in FIGS. 3 to 5, and the transmission case is indicated by a broken line. FIG. 10 is a perspective view of the transmission, showing a state in which the lid member of the transmission case is removed. FIG. 11 is a front view of the transmission, showing a state in which the lid member of the transmission case is removed. FIG. 12 is a perspective view of the transmission transmission mechanism. FIG. 13 is a partially developed cross-sectional view of the transmission. FIG. 14 is a schematic diagram of transmission of a working vehicle to which a modification of the transmission is applied. FIG. 15 is a hydraulic circuit diagram of the working vehicle.

Explanation of symbols

1 Working vehicle 20 Drive source 100 Transmission 110 HST
111 Pump shaft 113 Motor shaft 120 Planetary gear mechanism 130 Traveling gear transmission mechanism 140 Differential gear mechanism 210 PTO clutch mechanism 220 PTO gear transmission mechanism 300 Mission case 300a First space 300b Second space 301 First end wall 302 Second End wall 303 Intermediate wall 305 Peripheral wall 310 Lid member 320 Case body

Claims (4)

Power from the drive source, HST operatively connected to the drive source, a planetary gear mechanism for inputting constant speed power and variable speed power from the pump shaft and motor shaft of the HST, and travel for inputting the output of the planetary gear mechanism A transmission gear mechanism and a traveling gear transmission mechanism including a differential gear mechanism disposed downstream of the traveling gear transmission mechanism, and transmits power from the drive source to the pair of left and right main drive wheels. A vehicle transmission configured to be able to output to the outside via a PTO transmission mechanism including a PTO clutch mechanism disposed downstream of the pump shaft of the HST,
A transmission case that houses the planetary gear mechanism, the traveling gear transmission mechanism, the differential gear mechanism, and the PTO clutch mechanism;
The HST is connected to a first end wall on one side of the transmission case in the vehicle longitudinal direction,
The planetary gear mechanism, the traveling gear transmission mechanism, and the PTO clutch mechanism are accommodated in the transmission case so as to be positioned between the first end wall and the differential gear mechanism in the vehicle longitudinal direction. Vehicle transmission characterized by The transmission case includes a peripheral wall, a first end wall extending in a substantially vertical direction at an end of the peripheral wall on one side in the vehicle front-rear direction, and a first end wall extending in a substantially vertical direction on an end of the peripheral wall in the vehicle front-rear direction. Two end walls and an intermediate wall extending in a substantially vertical direction between the first and second end walls,
The planetary gear mechanism, the traveling gear transmission mechanism, and the PTO clutch mechanism are accommodated in a first space defined by the first end wall and the intermediate wall,
The vehicle transmission according to claim 1, wherein the differential gear mechanism is housed in a second space defined by the intermediate wall and the second end wall. The PTO transmission mechanism further includes a PTO gear transmission mechanism,
3. The vehicle transmission according to claim 2, wherein the PTO gear transmission mechanism is accommodated in the first space. The mission case has a first portion having the first end wall, and a second portion having the intermediate wall and the second end wall,
The vehicle transmission according to claim 2 or 3, wherein the first and second parts are detachably connected.

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