JP2007303595A - Transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple structured transmission intermediately installed in a traveling system transmission path leading from a driving source to a driving wheel, capable of making power from the driving source to the driving wheel not intercepted, and thus enabling comfortable traveling. <P>SOLUTION: A transmission 200 intermediately installed in the traveling system transmission path leading from the driving source 105 to the driving wheels 102, 102 comprises: an input shaft 210; an output shaft 220; a first transmission shaft 230 arranged in a first transmission path 200a, a first hydraulic clutch mechanism 240 and a first shifting mechanism 250; and a second transmission shaft 260 arranged in a second transmission path 200b, a second hydraulic clutch mechanism 270 and a second shifting mechanism 280. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transmission.

A transmission inserted in a traveling system transmission path from a driving source to driving wheels is conventionally known.
For example, the following Patent Document 1 discloses a multi-stage speed change in an input shaft to which power from a drive source is transmitted, an output shaft to which power of the input shaft is transmitted, and a transmission path between the input shaft and the output shaft. A transmission including a speed change mechanism for performing is described.

  In a traveling vehicle to which a conventional transmission is applied, for example, in a traveling system transmission path from a driving source to a driving wheel, power from the driving source is transmitted to the input shaft of the transmission via a clutch and transmitted to the input shaft. The motive power is shifted by the speed change mechanism along the transmission path between the input shaft and the output shaft, and the power changed by the speed change mechanism is transmitted to the drive wheels via the output shaft.

However, the conventional transmission has the following disadvantages.
In other words, after the drive of the drive source is started, the drive source is always in a rotating state. Therefore, when a speed change operation is performed, the power transmitted from the drive source to the drive wheels prior to the speed change operation is a clutch. After the transmission is interrupted and the shift operation is performed, the clutch in the power cutoff state is shifted to the power transmission state, and the power from the drive source is transmitted again.
Therefore, there is a problem that the power transmitted from the drive source to the drive wheels is interrupted during the shift operation.
Thus, if the power transmitted from the drive source to the drive wheels is cut off, for example, an impact occurs when the power cut-off state is shifted to the power transmission state, and traveling performance such as riding comfort deteriorates. If a shifting operation is performed when the traveling vehicle travels uphill, the vehicle may move backward when the power transmitted from the driving source to the driving wheels is interrupted.
Japanese Patent Laid-Open No. 11-78553

  The present invention has been made in view of such prior art, and is a transmission that is inserted in a traveling system transmission path from a drive source to a drive wheel, the power from the drive source to the drive wheel during a shifting operation. An object of the present invention is to provide a transmission having a simple structure that can prevent the vehicle from being shut off and thereby realize comfortable driving.

In order to achieve the above object, the present invention provides the following transmission according to the first aspect.
(1) Transmission of the first aspect A transmission inserted in a traveling system transmission path from a drive source to a drive wheel, a single input shaft operatively connected to the drive source, an output shaft,
A first transmission shaft disposed so as to constitute a first transmission path from the input shaft to the output shaft, and a first hydraulic clutch mechanism disposed in the first transmission path, wherein an external operation is performed A first hydraulic clutch mechanism that selectively transmits power of the first transmission shaft to the output shaft, and a first transmission mechanism that is disposed in the first transmission path, based on an external operation, A first transmission mechanism that performs multi-stage shifting in the first transmission path, and a second transmission path from the input shaft to the output shaft, the second transmission path being different from the first transmission path. A second transmission shaft provided, and a second hydraulic clutch mechanism disposed in the second transmission path, wherein the power of the second transmission shaft is selectively transmitted to the output shaft based on an external operation. A second hydraulic clutch mechanism and a second variable disposed in the second transmission path; A mechanism, the transmission being characterized in that a second transmission mechanism for multi-speed in based on an external operation, said second transmission path.

  In the transmission according to the first aspect of the present invention, the first transmission mechanism may perform a multi-stage transmission between the input shaft and the first transmission shaft based on an external operation, and the second transmission mechanism can be Based on an external operation, a multi-speed shift may be performed between the input shaft and the second transmission shaft.

  Specific examples of the transmission according to the first aspect of the present invention include the following. That is, the first speed change mechanism is a first speed change mechanism operation for selecting any one of a plurality of first speed change gear trains having different speed ratios and the plurality of first speed change gear trains. The second transmission mechanism includes a plurality of second transmission mechanism gear trains having the same transmission ratio as each of the plurality of first transmission mechanism gear trains, and the plurality of second transmission mechanism gears. An operation member for a second transmission mechanism that selects any one of the gear trains, and the first hydraulic clutch mechanism transmits power from the first transmission shaft to the output shaft at a first transmission ratio. The second hydraulic clutch mechanism is configured to transmit power from the second transmission shaft to the output shaft at a second speed ratio different from the first speed ratio. .

  In such an aspect, the gear provided on the input shaft so as not to be relatively rotatable may be configured to act as a drive-side gear in both the first transmission mechanism gear train and the second transmission mechanism gear train. Good.

The present invention also provides a transmission according to the second aspect described below.
(2) Transmission of the second aspect A transmission that is inserted in a traveling system transmission path from the drive source to the drive wheel, the first and second input shafts operatively connected to the drive source, the output shaft, A first transmission shaft disposed to form a first transmission path from the first input shaft to the output shaft, and a first hydraulic clutch mechanism disposed in the first transmission path, wherein an external operation A first hydraulic clutch mechanism for selectively transmitting the power of the first transmission shaft to the output shaft, and a first transmission mechanism disposed in the first transmission path, based on an external operation, A first transmission mechanism that performs multi-stage shifting in the first transmission path; a second transmission shaft that is arranged to form a second transmission path from the second input shaft to the output shaft; and the second transmission shaft. A second hydraulic clutch mechanism disposed in the path, A second hydraulic clutch mechanism for selectively transmitting the power of the second transmission shaft to the output shaft based on an external operation, and a second speed change mechanism disposed in the second transmission path, And a second speed change mechanism that performs multi-stage speed change in the second transmission path.

  Further, in the transmissions according to the first and second aspects of the present invention, the speed change mechanism in one of the first transmission path and the second transmission path is brought into an engagement state of a shift stage according to a first external operation. The transmission mechanism in the other transmission path is disengaged, the hydraulic clutch mechanism in the one transmission path is set in the power transmission state, and the hydraulic clutch mechanism in the other transmission path is set in the power cutoff state. When the second external operation is performed, the transmission mechanism in the other transmission path is moved to the second external operation while the transmission mechanism in the one transmission path is kept in the engaged state of the shift stage according to the first external operation. At the same time as the shift gear is engaged according to the condition and the hydraulic clutch mechanism in the one transmission path is gradually shifted from the power transmission state to the power cutoff state. It can be exemplified when configured hydraulic clutch mechanism gradually from the power cut-off state so as to shift the power transmission state in the other transmission path.

  In the transmissions according to the first and second aspects of the present invention, for example, power is transmitted from the first transmission shaft to the output shaft by the first hydraulic clutch mechanism, and the transmission is performed by the second hydraulic clutch mechanism. A first transmission state in which power from the second transmission shaft to the output shaft is interrupted, power is transmitted from the second transmission shaft to the output shaft by the second hydraulic clutch mechanism, and the first A second transmission state in which power from the first transmission shaft to the output shaft is interrupted by the hydraulic clutch mechanism can be taken.

When the transmissions of the first and second modes are in the first transmission state, in the first transmission state, in the second transmission path, the second hydraulic clutch mechanism disengages the second transmission shaft from the second transmission shaft. Since the power to the output shaft is cut off, the second transmission mechanism can perform a speed change operation on the second transmission path based on an external operation. On the other hand, in the first transmission path, since power is transmitted from the first transmission shaft to the output shaft by the first hydraulic clutch mechanism, the drive source to the drive wheels during the speed change operation. It can be set as the state where the power of is not interrupted. Then, after the speed change operation by the second speed change mechanism, the second hydraulic clutch mechanism can be operated so that the power from the second power transmission shaft is transmitted to the output shaft in a cut-off state. .
In the second transmission path, when the second hydraulic clutch mechanism is operated so as to transmit power from the second transmission shaft to the output shaft, the first transmission shaft in the first transmission path. The first hydraulic clutch mechanism may be operated so as to cut off the power to the output shaft in a state where the power from the transmission is in a transmission state.

When the transmission of the first and second modes is in the second transmission state, in the second transmission state, the first transmission shaft is moved by the first hydraulic clutch mechanism in the first transmission path. Since the power from the output shaft to the output shaft is cut off, the first transmission mechanism can perform a speed change operation on the first transmission path based on an external operation. On the other hand, in the second transmission path, since power is transmitted from the second transmission shaft to the output shaft by the second hydraulic clutch mechanism, the drive source to the drive wheels during the speed change operation. It can be set as the state where the power of is not interrupted. Then, after the speed change operation by the first speed change mechanism, the first hydraulic clutch mechanism can be operated so that the power from the first transmission shaft is transmitted to the output shaft in a cut-off state. .
In the first transmission path, when the first hydraulic clutch mechanism is operated so that power is transmitted from the first transmission shaft to the output shaft, the second transmission shaft in the second transmission path. The second hydraulic clutch mechanism may be operated so as to cut off the power to the output shaft in a state where the power from the transmission is transmitted.
As described above, according to the transmissions of the first and second aspects according to the present invention, the power from the drive source to the drive wheels can be prevented from being interrupted during the speed change operation. Thus, it is possible to effectively prevent the deterioration of running performance such as a comfortable running during the shifting operation.

  In the transmission according to the first aspect of the present invention, the first speed change mechanism includes any one of a plurality of first speed change gear trains and a plurality of first speed change gear trains having different speed ratios. A first transmission mechanism operating member that selects a plurality of second transmission mechanism gear trains having the same gear ratio as each of the plurality of first transmission mechanism gear trains. And a second transmission mechanism operation member that selects any one of the plurality of second transmission mechanism gear trains, wherein the first hydraulic clutch mechanism extends from the first transmission shaft to the output shaft. And the second hydraulic clutch mechanism transmits power from the second transmission shaft to the output shaft at a second speed ratio different from the first speed ratio. Configured as If it is can realize parts sharing of the plurality of first transmission mechanism gear train and a gear train for the plurality of second transmission mechanism, correspondingly the number of parts can be reduced, the cost can be reduced.

Hereinafter, preferred embodiments of a transmission according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic side view showing a traveling vehicle (here, a tractor) 100 to which a transmission 200 according to the present embodiment is applied.

A traveling vehicle 100 shown in FIG. 1 includes a main body 103 that suspends a pair of left and right front wheels 101 and 101 and a pair of left and right rear wheels 102 and 102 in the front and rear of the vehicle, and a bonnet 106 is disposed at the front of the main body 103. A drive source (here, engine) 105 is disposed inside the bonnet 106.
A driver's seat 107 is provided in the cabin 104. A main transmission lever 110 projects from a side portion of the driver's seat 107, and a steering handle 108 is disposed in front thereof.

In the traveling vehicle 100, a transmission case 109 provided with the transmission 200 is disposed behind the drive source 105, and the power from the drive source 105 is transmitted to the transmission 200 to change the speed. The driving force can be transmitted to the rear wheels 102, 102.
The traveling vehicle 100 is mounted with a work machine 300 via a work machine mounting device having a top link 112 and a lower link 113 at the rear, and a part of the power from the drive source 105 is transmitted to the transmission case. The PTO shaft 111 protruding from the rear surface 109 is transmitted to the working machine 300 via a telescopic transmission shaft (not shown) provided with universal joints at both ends to drive the working machine 300. Yes.

Next, the transmission 200 will be described in detail.
FIG. 2 is a side view showing a partially expanded transmission 200 according to the present embodiment, and FIG. 3 is a side view showing a partially enlarged transmission 200 shown in FIG.

  As shown in FIGS. 2 and 3, the transmission 200 is inserted in a traveling system transmission path from the drive source 105 to the drive wheels 102, 102, and includes an input shaft 210, an output shaft 220, A transmission shaft 230, a first hydraulic clutch mechanism 240, a first transmission mechanism 250, a second transmission shaft 260, a second hydraulic clutch mechanism 270, and a second transmission mechanism 280 are provided.

The input shaft 210 is a single input shaft that is operatively connected to the drive source 105, and the output shaft 220 is disposed substantially parallel to the input shaft 210 here.
The transmission 200 includes a first transmission path 200a from the input shaft 210 to the output shaft 220, and a second transmission path 200b from the input shaft 210 to the output shaft 220, the first transmission path 200a Are formed with different second transmission paths 200b.
The first transmission shaft 230, the first hydraulic clutch mechanism 240, and the first transmission mechanism 250 are disposed in the first transmission path 200a, and the second transmission shaft 260, the second hydraulic clutch. The mechanism 270 and the second speed change mechanism 280 are disposed in the second transmission path 200b.

That is, the first transmission shaft 230 is disposed so as to constitute the first transmission path 200a, and here, is disposed substantially parallel to the input shaft 210.
The first hydraulic clutch mechanism 240 is disposed in the first transmission path 200a, and is configured to selectively transmit the rotational power of the first transmission shaft 230 to the output shaft 220 based on an external operation. Has been.
The first transmission mechanism 250 is disposed in the first transmission path 200a, and is configured to perform multi-stage transmission in the first transmission path 200a based on an external operation.

The second transmission shaft 260 is disposed so as to constitute the second transmission path 200b, and here is disposed substantially parallel to the input shaft 210.
The second hydraulic clutch mechanism 270 is disposed in the second transmission path 200b, and is configured to selectively transmit the rotational power of the second transmission shaft 260 to the output shaft 220 based on an external operation. Has been.
The second transmission mechanism 280 is disposed in the second transmission path 200b, and is configured to perform multi-stage transmission in the second transmission path 200b based on an external operation.

  With such a configuration, for example, the transmission 200 transmits rotational power from the first transmission shaft 230 to the output shaft 220 by the first hydraulic clutch mechanism 240, and the second hydraulic clutch mechanism. In the first transmission state in which the rotational power from the second transmission shaft 260 to the output shaft 220 is interrupted at 270, and from the second transmission shaft 260 to the output shaft 220 in the second hydraulic clutch mechanism 270. A second transmission state in which the rotational power is transmitted and the rotational power from the first transmission shaft 230 to the output shaft 220 is blocked by the first hydraulic clutch mechanism 240 can be taken.

When the transmission 200 is in the first transmission state, in the first transmission state, in the second transmission path 200b, the second hydraulic clutch mechanism 270 causes the second transmission shaft 260 to the output shaft 220. Since the rotational power to is cut off, the second transmission mechanism 280 performs a shift operation on the second transmission path 200b based on an external operation (here, an external operation by the main transmission lever 110). Can do. On the other hand, in the first transmission path 200a, rotational power is transmitted from the first transmission shaft 230 to the output shaft 220 by the first hydraulic clutch mechanism 240. The rotational power from 105 to the drive wheels 102 and 102 can be made uninterrupted. Then, after the speed change operation by the second speed change mechanism 280, the second hydraulic clutch mechanism 270 is so transmitted that the rotary power from the second transmission shaft 260 is transmitted to the output shaft 220 in a cut-off state. Can be activated.
In the present embodiment, in the second transmission path 200b, the first hydraulic clutch mechanism 270 is operated to transmit the rotational power from the second transmission shaft 260 to the output shaft 220, while the first transmission clutch 260 is operated. In the transmission path 200a, the first hydraulic clutch mechanism 240 is operated such that the rotational power from the first transmission shaft 230 is cut off from the output shaft 220 in the transmission state.

Further, when the transmission 200 is in the second transmission state, in the second transmission state, the output from the first transmission shaft 230 by the first hydraulic clutch mechanism 240 in the first transmission path 200a. Since the rotational power to the shaft 220 is cut off, the first transmission mechanism 250 performs a speed change operation on the first transmission path 200a based on an external operation (here, an external operation by the main transmission lever 110). It can be carried out. On the other hand, in the second transmission path 200b, rotational power is transmitted from the second transmission shaft 260 to the output shaft 220 by the second hydraulic clutch mechanism 270. The rotational power from 105 to the drive wheels 102 and 102 can be made uninterrupted. Then, after the speed change operation by the first speed change mechanism 250, the first hydraulic clutch mechanism 240 is configured such that the rotational power from the first transmission shaft 230 is transmitted to the output shaft 220 in a cut-off state. Can be activated.
In the present embodiment, in the first transmission path 200a, the second hydraulic clutch mechanism 240 is operated to transmit the rotational power from the first transmission shaft 230 to the output shaft 220, and the second hydraulic clutch mechanism 240 is operated. In the transmission path 200b, the second hydraulic clutch mechanism 270 is operated such that the rotational power from the second transmission shaft 260 is cut off from the output shaft 220 in the transmission state.

  As described above, according to the transmission 200 according to the present embodiment, the rotational power from the drive source 105 to the drive wheels 102 and 102 can be prevented from being interrupted during a shift operation. It is possible to effectively prevent deterioration in running performance such as ride comfort. As a result, it is possible to realize comfortable travel during the speed change operation.

  The first and second speed change mechanisms 250 and 280 may be arranged at any position of the first and second transmission paths 200a and 200b, respectively, but in the present embodiment, the first speed change mechanism 250 and 280 are arranged. The mechanism 250 is configured to perform multi-stage shifting between the input shaft 210 and the first transmission shaft 230 based on an external operation, and the second transmission mechanism 280 is configured to perform the input shaft based on an external operation. 210 and the second transmission shaft 260 are configured to perform multi-speed shifting.

The first speed change mechanism 250 selects a first gear selected from the plurality of first speed change mechanism gear trains 251 and the plurality of first speed change mechanism gear trains 251 having different speed ratios. And a mechanism operation member 252.
The second transmission mechanism 280 includes a plurality of second transmission mechanism gear trains 281 having the same transmission ratio as each of the plurality of first transmission mechanism gear trains 251 and the plurality of second transmission mechanism gear trains 281. And a second speed change mechanism operation member 282 for selecting any one of the gears.
The first hydraulic clutch mechanism 240 is configured to transmit power from the first transmission shaft 230 to the output shaft 220 at a first gear ratio, and the second hydraulic clutch mechanism 270 is configured to transmit the second transmission. Power is transmitted from shaft 260 to output shaft 220 at a second speed ratio different from the first speed ratio.

  By providing such a configuration, the transmission 200 can realize parts sharing of the plurality of first transmission gear trains 251 and the plurality of second transmission gear trains 281, thereby reducing the number of parts and reducing the cost. Reduction can be achieved.

  More specifically, in the present embodiment, the input shaft 210, the output shaft 220, the first transmission shaft 230, and the second transmission shaft 260 are supported by the transmission case 109 so as to be rotatable about an axis. Has been. Reference numeral 105b indicates a flywheel.

Here, the input shaft 210 is disposed substantially parallel to the drive shaft 105a of the drive source 105 so that the rotational power from the drive source 105 is transmitted, and the drive transmission mechanism 114 is connected to the drive shaft 105a. It is connected through.
Here, the drive transmission mechanism 114 includes a drive gear 114a provided so as not to rotate relative to the drive shaft 105a, and a driven gear 114b engaged with the drive gear 114a, and cannot rotate relative to the input shaft 210. And a driven gear 114b provided.

  The first speed change mechanism 250 is provided on one of the input shaft 210 and the first transmission shaft 230 (here, the first transmission shaft 230), and the input shaft 210 and the second transmission shaft 230 are provided. The second speed change mechanism 280 is provided on one of the 260 (here, the second transmission shaft 260).

Specifically, gears (in this case, the first drive gear 210a, the second drive gear 210b, the third drive gear 210c, and the fourth drive gear 210d) that are provided on the input shaft 210 so as not to rotate relative to each other are in the first shift. The mechanism gear train 251 and the second speed change mechanism gear train 281 are configured to act as drive side gears.
The third drive gear 210c also serves as the driven gear 114b.

That is, the plurality of first transmission gear trains 251 include a first transmission gear train 251a having a low speed transmission ratio A including a first driven gear 251a ′ and the first drive gear 210a, and a second driven gear 251b. 'And a third speed gear train 251b having a medium / low speed gear ratio B including the second drive gear 210b, and a medium / high speed gear ratio C including a third driven gear 251c' and the third drive gear 210c. The fifth gear train 251c and the seventh gear train 251d having a high speed gear ratio D including the fourth driven gear 251d ′ and the fourth drive gear 210d.
Here, the first to fourth driven gears 251a ′ to 251d ′ are supported by the first transmission shaft 230 so as to be rotatable about an axis.

The plurality of second transmission gear trains 281 include a second transmission gear train 281a having a first transmission gear 281a 'and the first drive gear 210a and a low transmission gear ratio A, and a second driven gear. The medium and low speed gear ratio 281b including the third low speed gear ratio 281b including the second low gear ratio 281b ′ and the second drive gear 210b, and the third driven gear 281c ′ and the third drive gear 210c. A sixth gear train 281c for transmission C that is C, and a gear train 281d for eighth transmission that is the high-speed gear ratio D including the fourth driven gear 281d ′ and the fourth drive gear 210d.
Here, the first to fourth driven gears 281a ′ to 281d ′ are supported by the second transmission shaft 260 so as to be rotatable about an axis.

  Here, each of the first transmission mechanism 250 and the second transmission mechanism 280 is a synchronous meshing multi-stage transmission mechanism configured to shift in a state where the driving gear and the driven gear are meshed in advance. Yes.

Specifically, the first speed change mechanism operating member 252 includes a first low speed shifter mechanism 252a and a first high speed shifter mechanism 252b, and the second speed change mechanism operating member 282 is a second low speed shifter mechanism. A mechanism 282a and a second high speed shifter mechanism 282b are provided.
Here, the first low-speed shifter mechanism 252a and the first high-speed shifter mechanism 252b, and the second low-speed shifter mechanism 282a and the second high-speed shifter mechanism 282b are all friction type double synchronous clutches. .

  That is, the first speed change mechanism operating member 252 is either the first driven gear 251a ′ in the first speed change gear train 251a or the second driven gear 251b ′ in the third speed change gear train 251b. The first low-speed shifter mechanism 252a configured to select one of the gears, the third driven gear 251c ′ in the fifth gear shift gear train 251c, and the fourth driven gear in the seventh gear shift train 251d. And the first high-speed shifter mechanism 252b configured to select any one of the gears 251d ′.

  The second speed change mechanism operating member 282 is either one of the first driven gear 281a 'in the second speed change gear train 281a and the second driven gear 281b' in the fourth speed change gear train 281b. The second low-speed shifter mechanism 282a configured to select one of the gears, the third driven gear 281c ′ in the sixth high-speed gear train 281c, and the fourth driven in the eighth gear shift train 281d. A second high-speed shifter mechanism 282b configured to select any one of the gears 281d ′.

The first low-speed shifter mechanism 252a is provided on the first transmission shaft 230, and is selectively slid between the first driven gear 251a ′ and the second driven gear 251b ′. When the first driven gear 251a ′ is slid, the rotational power of the input shaft 210 is transferred to the first transmission shaft via the first drive gear 210a and the first driven gear 251a ′. 230 and is slid by the second driven gear 251b ′, the rotational power of the input shaft 210 is transmitted via the second drive gear 210b and the second driven gear 251b ′. The first transmission shaft 230 can be transmitted.
The first low-speed shifter mechanism 252a can be in a neutral state, and in this state, the first transmission shaft from the input shaft 210 through the first drive gear 210a and the first driven gear 251a ′. The rotational power transmitted to 230 and the rotational power transmitted from the input shaft 210 to the first transmission shaft 230 via the second drive gear 210b and the second driven gear 251b ′ can be cut off.

The first high-speed shifter mechanism 252b is provided on the first transmission shaft 230 and is selectively slid between the third driven gear 251c ′ and the fourth driven gear 251d ′. When the third driven gear 251c ′ is slid, the rotational power of the input shaft 210 is transmitted via the third drive gear 210c and the third driven gear 251c ′ to the first transmission. When transmitted to the shaft 230 and slid to the fourth driven gear 251d ′, the rotational power of the input shaft 210 is transmitted via the fourth drive gear 210d and the fourth driven gear 251d ′. The first transmission shaft 230 can be transmitted.
The first high-speed shifter mechanism 252b can be in a neutral state, and in this state, the first transmission shaft from the input shaft 210 via the third drive gear 210c and the third driven gear 251c ′. The rotational power transmitted to 230 and the rotational power transmitted from the input shaft 210 to the first transmission shaft 230 via the fourth drive gear 210d and the fourth driven gear 251d ′ can be cut off.

The second low-speed shifter mechanism 282a is provided on the second transmission shaft 260 and is selectively slid between the first driven gear 281a 'and the second driven gear 281b'. When the first driven gear 281a ′ is slid, the rotational power of the input shaft 210 is transmitted through the first drive gear 210a and the first driven gear 281a ′. 2 When transmitted to the transmission shaft 260 and slid on the second driven gear 281b ′, the rotational power of the input shaft 210 is transmitted to the second drive gear 210b and the second driven gear 281b ′. Via the second transmission shaft 260.
The second low speed shifter mechanism 282a can be in a neutral state, and in this state, the second transmission shaft from the input shaft 210 through the first drive gear 210a and the first driven gear 281a ′. The rotational power transmitted to 260 and the rotational power transmitted from the input shaft 210 to the second transmission shaft 260 via the second drive gear 210b and the second driven gear 281b ′ can be cut off.

The second high speed shifter mechanism 282b is provided on the second transmission shaft 260 and is selectively slid between the third driven gear 281c ′ and the fourth driven gear 281d ′. When the second driven gear 281c ′ is slid, the rotational power of the input shaft 210 is transmitted to the second transmission gear via the third drive gear 210c and the third driven gear 281c ′. When transmitting to the shaft 260 and sliding on the fourth driven gear 281d ′, the rotational power of the input shaft 210 is transmitted via the fourth drive gear 210d and the fourth driven gear 281d ′. The second transmission shaft 260 can be transmitted.
The second high-speed shifter mechanism 282b can be in a neutral state, and in this state, the second transmission shaft from the input shaft 210 via the third drive gear 210c and the third driven gear 281c ′. The rotational power transmitted to 260 and the rotational power transmitted from the input shaft 210 to the second transmission shaft 260 through the fourth drive gear 210d and the fourth driven gear 281d ′ can be cut off.

The first hydraulic clutch mechanism 240 is provided on the first transmission shaft 230 in order to selectively transmit the rotational power of the first transmission shaft 230 to the output shaft 220 based on an external operation. Yes.
That is, the first hydraulic clutch mechanism 240 includes a first clutch cylinder 241, a pair of first friction plates 242 and 243, a first piston 244, and a first biasing member 245.
The first clutch cylinder 241 is provided on the first transmission shaft 230 so as not to be relatively rotatable.

  The pair of first friction plates 242 and 243 are arranged so that the friction surfaces thereof face each other, one 242 is provided in the first clutch cylinder 241 and the other 243 is the first transmission. The first transmission gear 116a, which will be described later, is supported on the shaft 230 so as to be rotatable about the axis, and at least one (here, the one friction plate 242) is axially arranged so as to be frictionally engaged with the other. Is slidable.

The first piston 244 is connected to a slidable friction plate (here, the one friction plate 242) of the pair of first friction plates 242 and 243, and is described later. The friction surfaces of the pair of first friction plates 242 and 243 can be frictionally engaged with each other in the state in which the oil chamber 246 that receives hydraulic oil from a mechanism (not shown) is formed (here, the one friction plate) It is movable in the axial direction (so that 242 can be frictionally engaged with the other friction plate 243).
In the present embodiment, the first piston 244 has a sliding contact portion 244 a that forms a fluid contact with the first clutch cylinder 241 to form the oil chamber 246.
The first biasing member 245 is configured to bias the first piston 244 so that the friction surfaces of the pair of first friction plates 242 and 243 are not engaged with each other. One end is connected to the first clutch cylinder 241 and the other end is a coil spring connected to the first piston 244.

In addition, the second hydraulic clutch mechanism 270 is provided on the second transmission shaft 260 in order to selectively transmit the rotational power of the second transmission shaft 260 to the output shaft 220 based on an external operation. It has been.
That is, the second hydraulic clutch mechanism 270 includes a second clutch cylinder 271, a pair of second friction plates 272, 273, a second piston 274, and a second urging member 275.
The second clutch cylinder 271 is provided on the second transmission shaft 260 so as not to rotate relative to the second transmission shaft 260.

  The pair of second friction plates 272 and 273 are arranged so that the friction surfaces thereof face each other, one 272 is provided in the second clutch cylinder 271 and the other 273 is the second transmission. It is provided in a second transmission gear 117a, which will be described later, supported rotatably on the shaft 260, and at least one (here, the one friction plate 272) is axially oriented so that it can frictionally engage with the other. Is slidable.

The second piston 274 is connected to a slidable friction plate (here, the one friction plate 272) of the pair of second friction plates 272 and 273, and the hydraulic mechanism So that the friction surfaces of the pair of second friction plates 272 and 273 can be frictionally engaged with each other in the state in which the oil chamber 276 for receiving the hydraulic oil from is formed (here, the one friction plate 272 is the other friction plate). It is movable in the axial direction (so that it can be frictionally engaged with the friction plate 273).
In the present embodiment, the second piston 274 has a sliding contact portion 274a that forms a fluid contact with the second clutch cylinder 271 to form the oil chamber 276.
The second urging member 275 is configured to urge the second piston 274 such that the friction surfaces of the pair of second friction plates 272 and 273 are not engaged with each other. One end is connected to the second clutch cylinder 271 and the other end is a coil spring connected to the second piston 274.
Here, the first and second hydraulic clutch mechanisms 240 and 270 are provided on the first and second transmission shafts 230 and 260, respectively, but may be provided on the output shaft 220.

The first hydraulic clutch mechanism 240 further includes a first drive transmission mechanism 116 that transmits rotational power from the first transmission shaft 230 to the output shaft 220 at the first gear ratio.
Specifically, the first drive transmission mechanism 116 includes the first transmission gear 116a that is supported by the first transmission shaft 230 so as to be rotatable about its axis, and the first output gear 116b that meshes with the first transmission gear 116a. The output shaft 220 includes a first output gear 116b provided so as not to rotate relative to the output shaft 220. The first transmission gear 116a and the first output gear 116b allow the output shaft 220 to move from the first transmission shaft 230 to the output shaft 220. Is configured to transmit power at the first gear ratio.
The second hydraulic clutch mechanism 270 further includes a second drive transmission mechanism 117 that transmits rotational power from the second transmission shaft 260 to the output shaft 220 at the second speed ratio.
Specifically, the second drive transmission mechanism 117 includes a second transmission gear 117a that is supported by the second transmission shaft 260 so as to be rotatable about an axis thereof, and a second output gear 117b that meshes with the second transmission gear 117a. The second output gear 117b is provided on the output shaft 220 so as not to rotate relative to the output shaft 220. The output shaft 220 is connected to the output shaft 220 from the second transmission shaft 260 by the second transmission gear 117a and the second output gear 117b. Is configured to transmit power at the second gear ratio.

Here, when power is transmitted from the first transmission shaft 230 to the output shaft 220 at the first transmission gear ratio, the transmission gear ratio of the first transmission gear train 251a is the same as that of the first transmission gear train 251a. When the low speed gear ratio A is set, the first speed change is performed, and when power is transmitted from the second transmission shaft 260 to the output shaft 220 at the second speed ratio, the speed change by the second speed change mechanism 280 is performed. When the ratio is the low-speed gear ratio A of the second gear shift train 281a, the second gear shift is obtained, which is faster than the first gear shift.
When power is transmitted from the first transmission shaft 230 to the output shaft 220 at the first transmission gear ratio, the transmission gear ratio by the first transmission mechanism 250 is the medium / low speed transmission gear ratio B of the third transmission gear train 251b. In the case where the third speed change is obtained, which is faster than the second speed change, and the power is transmitted from the second transmission shaft 260 to the output shaft 220 at the second speed change ratio, When the speed ratio of the second speed change mechanism 280 is set to the medium / low speed speed ratio B of the fourth speed change gear train 281b, the fourth speed change is obtained, which is faster than the third speed change.

In addition, when power is transmitted from the first transmission shaft 230 to the output shaft 220 at the first speed ratio, the medium speed ratio of the fifth speed change gear train 251c is determined by the speed ratio of the first speed change mechanism 250. In the case where the ratio C is set to be the fifth speed change, which is faster than the fourth speed change, and the power is transmitted from the second transmission shaft 260 to the output shaft 220 at the second speed change ratio, When the speed ratio of the second speed change mechanism 280 is set to the medium / high speed speed ratio C of the sixth speed change gear train 281c, the speed is set to be the sixth speed at which a speed higher than that of the fifth speed change is obtained.
When power is transmitted from the first transmission shaft 230 to the output shaft 220 at the first speed ratio, the speed ratio by the first speed change mechanism 250 is equal to the high speed speed ratio D of the seventh speed change gear train 251d. In this case, when the speed is higher than the sixth speed, the seventh speed is obtained, and power is transmitted from the second transmission shaft 260 to the output shaft 220 at the second speed ratio. When the speed ratio by the speed change mechanism 280 is set to the high speed speed ratio D of the eighth speed change gear train 281d, the eighth speed change is obtained, which is faster than the seventh speed change.

The hydraulic mechanism is configured to supply hydraulic oil to the first and second hydraulic clutch mechanisms 240 and 270 from a hydraulic source such as an auxiliary pump operatively connected to the drive source 105.
Specifically, the hydraulic mechanism includes a first hydraulic oil line having one end fluidly connected to a hydraulic pressure source and the other end fluidly connected to the first hydraulic clutch mechanism 240 (here, the oil chamber 246). A second hydraulic oil line having one end fluidly connected to a hydraulic pressure source and the other end fluidly connected to the second hydraulic clutch mechanism 270 (here, the oil chamber 276). The hydraulic oil is supplied and discharged from the first and second hydraulic oil lines to the first and second hydraulic clutch mechanisms 240 and 270 by a hydraulic oil valve.
The hydraulic mechanism may be configured to be mechanically operated by an external operation (for example, by a link mechanism operatively connected to the main transmission lever 110). The hydraulic oil valve (for example, an electromagnetic valve) is configured to be controlled.
That is, the transmission further includes a control device (not shown), and the control device is a transmission mechanism (200a or 200b) in one of the first transmission path 200a and the second transmission path 200b. 250 or 280) is brought into the engaged state of the shift stage according to the first external operation (here, the first external operation by the main shift lever 110), and the speed change mechanism (280 or 250) is disengaged and the hydraulic clutch mechanism (240 or 270) in the one transmission path (200a or 200b) is in a power transmission state and the hydraulic clutch mechanism in the other transmission path (200b or 200a). (270 or 240) is set to the power shut-off state, and then the next second external operation (here, When the second external operation by the main transmission lever 110 is performed, the transmission mechanism (250 or 280) in the one transmission path (200a or 200b) is brought into the engaged state of the shift stage according to the first external operation. In this state, the transmission mechanism (280 or 250) in the other transmission path (200b or 200a) is brought into the engagement state of the shift stage according to the second external operation, and in the one transmission path (200a or 200b). The hydraulic clutch mechanism (240 or 270) is gradually shifted from the power transmission state to the power cutoff state, and at the same time, the hydraulic clutch mechanism (270 or 240) in the other transmission path (200b or 200a) is gradually powered from the power cutoff state. It is comprised so that it may transfer to a transmission state.
Specifically, the control device includes a central processing unit (CPU) and a storage unit. The storage unit stores a control program, and includes, for example, a ROM and a RAM.

Next, a specific example of the speed change operation by the transmission 200 will be described.
After the drive of the drive source 105 is started, the drive source 105 is always in a rotating state. Therefore, the rotational power is transmitted from the drive shaft 105a and the drive shaft 105a through the gears 114a and 114b. The input shaft 210, the drive gears 210a to 210c provided on the input shaft 210, and the driven gears 251a ′ to 251d ′ and 281a ′ to 281d ′ respectively meshing with the drive gears 210a to 210c are always axial lines. It is in a rotating state around.

(First transmission state)
At this time, in the first transmission path 200a, the first low-speed shifter mechanism 252a is slid toward the first driven gear 251a ′ in the first transmission gear train 251a, and the first high-speed shifter mechanism When the 252b is in a neutral state and the rotational power is transmitted from the first transmission shaft 230 to the output shaft 220 by the first hydraulic clutch mechanism 240, the input shaft 210, the first drive The gear 210 a, the first driven gear 251 a ′, the first low-speed shifter mechanism 252 a, the first transmission shaft 230, the first drive transmission mechanism 116 in the first hydraulic clutch mechanism 240, and the output shaft 220 pass through the output shaft 220. A transmission path for the first speed change is formed.
On the other hand, in the second transmission path 200b, the rotational power from the second transmission shaft 260 to the output shaft 220 is blocked by the second hydraulic clutch mechanism 270.

(Transition from the first transmission state to the second transmission state)
Next, in the second transmission path 200b, the second low speed shifter mechanism 282a is slid toward the first driven gear 281a ′ side in the second speed change gear train 281a, and the second high speed shifter mechanism 282b is In the neutral state, rotational power is transmitted from the input shaft 210 to the second transmission shaft 260 via the first drive gear 210a, the first driven gear 281a ′, and the second low-speed shifter mechanism 282a. Communicated.
Further, when rotational power is transmitted from the second transmission shaft 260 to the output shaft 220 by the second hydraulic clutch mechanism 270, the input shaft 210, the first drive gear 210a, and the first driven gear 281a ′. , A transmission path for the second speed change is formed through the second low speed shifter mechanism 282a, the second transmission shaft 260, the second drive transmission mechanism 117 in the second hydraulic clutch mechanism 270, and the output shaft 220. .

Here, during the shifting operation, the hydraulic mechanism gradually increases the operating hydraulic pressure to the hydraulic clutch mechanism that shifts from the power transmission state to the power cutoff state among the first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270. Along with this, the hydraulic pressure to the hydraulic clutch mechanism that shifts from the power cut-off state to the power transmission state of the first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270 is gradually increased accordingly. ing.
FIG. 4 is a graph showing temporal changes in the operating hydraulic pressure supplied from the hydraulic mechanism to the first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270 during a speed change operation.
In FIG. 4, symbol α indicates a change in operating hydraulic pressure to the hydraulic clutch mechanism that shifts from the power transmission state to the power cut-off state among the first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270. Reference symbol β represents a change in operating hydraulic pressure from the first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270 to the hydraulic clutch mechanism that shifts from the power cut-off state to the power transmission state.

Α is a change in operating hydraulic pressure to the first hydraulic clutch mechanism 240 that shifts from the power transmission state to the power cutoff state, and β is the second hydraulic clutch mechanism that shifts from the power cutoff state to the power transmission state. The operating hydraulic pressure changes to 270.
In other words, the hydraulic pressure from the hydraulic mechanism to the first hydraulic clutch mechanism 240 gradually decreases, while the hydraulic pressure from the hydraulic mechanism to the second hydraulic clutch mechanism 270 gradually increases.

For example, at the start of hydraulic oil pressure reduction to the first hydraulic clutch mechanism 240 and at the start of hydraulic oil pressurization to the second hydraulic clutch mechanism 270 (see γ1), the first hydraulic clutch mechanism 240 has the pair of The friction surfaces of the first friction plates 242 and 243 are frictionally engaged, and the friction surfaces of the pair of second friction plates 272 and 273 are disengaged in the second hydraulic clutch mechanism 270. Yes.
When the operating hydraulic pressure to the first hydraulic clutch mechanism 240 is further reduced and the operating hydraulic pressure to the second hydraulic clutch mechanism 270 is further increased (see γ2), the first hydraulic clutch mechanism 240 Although the friction surfaces of the first friction plates 242 and 243 remain in a friction engagement state, in the second hydraulic clutch mechanism 270, the friction surfaces of the pair of second friction plates 272 and 273 are in a sliding state.

When the operating hydraulic pressure to the first hydraulic clutch mechanism 240 is further decreased and the operating hydraulic pressure to the second hydraulic clutch mechanism 270 is further increased (see γ3), the first hydraulic clutch mechanism 240 has the pair of first hydraulic clutches. While the friction surfaces of the first friction plates 242 and 243 are in a sliding state, in the second hydraulic clutch mechanism 270, the friction surfaces of the pair of first friction plates 272 and 273 are in a friction engagement state.
When the hydraulic oil pressure reduction to the first hydraulic clutch mechanism 240 is finished and hydraulic oil pressure to the second hydraulic clutch mechanism 270 is finished (see γ4), the first hydraulic clutch mechanism 240 has the pair of pairs. The friction surfaces of the first friction plates 242 and 243 are disengaged, and in the second hydraulic clutch mechanism 270, the friction surfaces of the pair of first friction plates 272 and 273 are frictionally engaged.

(Second transmission state)
Then, in the first transmission path 200a, the rotational power from the first transmission shaft 230 to the output shaft 220 is interrupted by the first hydraulic clutch mechanism 240, and in the second transmission path 200b, the first transmission path 200a Only a two-speed transmission path is formed.
Thus, the drive source 105 to the drive wheel during the transition from the first transmission state (here, the first shift state) to the second transmission state (here, the second shift state). It can be set as the state by which the rotational power to 102,102 is not interrupted | blocked.

(Transition from the second transmission state to the first transmission state)
Next, in the first transmission path 200a, the first low speed shifter mechanism 252a is slid toward the second driven gear 251b ′ side in the third speed change gear train 251b, and the first high speed shifter mechanism 252b is When in a neutral state, rotational power is transmitted from the input shaft 210 to the first transmission shaft 230 via the second drive gear 210b, the second driven gear 251b ′, and the first low-speed shifter mechanism 252a. Communicated.
Further, when rotational power is transmitted from the first transmission shaft 230 to the output shaft 220 by the first hydraulic clutch mechanism 240, the input shaft 210, the second drive gear 210b, and the second driven gear 251b ′. , A transmission path for the third shift is formed through the first low-speed shifter mechanism 252a, the first transmission shaft 230, the first drive transmission mechanism 116 in the first hydraulic clutch mechanism 240, and the output shaft 220. .

In FIG. 4, α is a change in operating hydraulic pressure to the second hydraulic clutch mechanism 270 that shifts from the power transmission state to the power cutoff state, and β is the first hydraulic pressure that shifts from the power cutoff state to the power transmission state. The hydraulic pressure is changed to 1 hydraulic clutch mechanism 240.
That is, the operating hydraulic pressure from the hydraulic mechanism to the second hydraulic clutch mechanism 270 gradually decreases, while the operating hydraulic pressure from the hydraulic mechanism to the first hydraulic clutch mechanism 240 gradually increases.

As shown in FIG. 4, for example, at the start of decompression of hydraulic fluid to the second hydraulic clutch mechanism 270 and at the start of pressurization of hydraulic fluid to the first hydraulic clutch mechanism 240 (see γ1), the second hydraulic pressure is increased. In the clutch mechanism 270, the friction surfaces of the pair of second friction plates 272 and 273 are in a friction engagement state, and in the first hydraulic clutch mechanism 240, the friction surfaces of the pair of first friction plates 242 and 243 are It is in a disengaged state.
When the operating oil pressure to the second hydraulic clutch mechanism 270 further decreases and the operating oil pressure to the first hydraulic clutch mechanism 240 further increases (see γ2), the second hydraulic clutch mechanism 270 Although the friction surfaces of the second friction plates 272 and 273 remain in a friction engagement state, in the first hydraulic clutch mechanism 240, the friction surfaces of the pair of first friction plates 242 and 243 are in a sliding state.

When the operating oil pressure to the second hydraulic clutch mechanism 270 further decreases and the operating oil pressure to the first hydraulic clutch mechanism 240 further increases (see γ3), the second hydraulic clutch mechanism 270 causes the pair of first While the friction surfaces of the two friction plates 272 and 273 are in a sliding state, in the first hydraulic clutch mechanism 240, the friction surfaces of the pair of second friction plates 242 and 243 are in a friction engagement state.
When the hydraulic oil pressure reduction to the second hydraulic clutch mechanism 270 ends and when the hydraulic oil pressure to the first hydraulic clutch mechanism 240 ends (see γ4), the second hydraulic clutch mechanism 270 includes the pair of hydraulic oils. The friction surfaces of the second friction plates 272 and 273 are disengaged, and in the first hydraulic clutch mechanism 240, the friction surfaces of the pair of first friction plates 242 and 243 are frictionally engaged.

(First transmission state)
Then, in the second transmission path 200b, rotational power from the second transmission shaft 260 to the output shaft 220 is cut off by the second hydraulic clutch mechanism 270, and in the first transmission path 200a, the second transmission path 200b Only a three-speed transmission path is formed.
As described above, even when the second transmission state (here, the second shift state) is shifted to the first transmission state (here, the third shift state), the drive source 105 drives the drive. A state in which the rotational power to the wheels 102, 102 is not interrupted can be achieved.

  Here, the description has been given of the case of shifting from the first shift to the second shift and the case of shifting from the second shift to the third shift among the first to eighth shifts. It is possible to switch to another gear stage by the shifting operation.

  When shifting to the fourth speed change, the input shaft 210, the second drive gear 210b, the second driven gear 281b ′, and the second low-speed shifter mechanism 282a in the second transmission path 200b. , When the fourth transmission transmission path is formed through the second transmission shaft 260, the second drive transmission mechanism 117 and the output shaft 220 in the second hydraulic clutch mechanism 270, and is shifted to the fifth transmission. In the first transmission path 200a, the input shaft 210, the third drive gear 210c, the third driven gear 251c ′, the first high-speed shifter mechanism 252b, the first transmission shaft 230, the first A transmission path for the fifth shift is formed through the first drive transmission mechanism 116 and the output shaft 220 in the hydraulic clutch mechanism 240.

When shifting to the sixth speed change, in the second transmission path 200b, the input shaft 210, the third drive gear 210c, the third driven gear 281c ′, the second high speed shifter mechanism 282b, When the sixth transmission transmission path is formed through the second transmission shaft 260, the second drive transmission mechanism 117 and the output shaft 220 in the second hydraulic clutch mechanism 270, and the transmission is shifted to the seventh transmission. In the second transmission path 200b, in the first transmission path 200a, the input shaft 210, the fourth drive gear 210d, the fourth driven gear 251d ′, the first high-speed shifter mechanism 252b, and the first transmission A transmission path for the seventh speed change is formed through the shaft 230, the first drive transmission mechanism 116 in the first hydraulic clutch mechanism 240, and the output shaft 220. .
Further, when shifting to the eighth speed change, the input shaft 210, the fourth drive gear 210d, the fourth driven gear 281d ′, and the second high-speed shifter mechanism 282b in the second transmission path 200b. The eighth transmission shaft is formed through the second transmission shaft 260, the second drive transmission mechanism 117 in the second hydraulic clutch mechanism 270, and the output shaft 220.

The transmission 200 according to the present embodiment includes a forward / reverse switching device 400 that switches the rotation direction of the output shaft 220 in addition to the above configuration.
Specifically, the forward / reverse switching device 400 includes a forward gear 410, a reverse gear 420, an intermediate idle gear 430, and a forward / reverse switching shifter mechanism 440.
The forward gear 410 is supported on the output shaft 220 so as to be rotatable about its axis, and is an output transmission shaft 910 disposed substantially in parallel with the output shaft 220, and operates on the drive wheels 102, 102. The coupled output transmission shaft 910 (here, the main drive shaft of the differential gear device 900) meshes with a first gear 920 provided so as not to be relatively rotatable.
The reverse gear 420 is supported by the output shaft 220 so as to be rotatable about its axis, and meshes with the intermediate idle gear 430.

The intermediate idle gear 430 meshes with the reverse gear 420 and meshes with a second gear 930 provided on the output transmission shaft 910 so as not to be relatively rotatable.
The forward / reverse switching shifter mechanism 440 is provided on the output shaft 220 and is selectively slid between the forward gear 410 and the reverse gear 420. When sliding on the gear 410, the rotational power of the output shaft 220 is transmitted to the output transmission shaft 910 via the forward gear 410 and the first gear 920, and the reverse gear. When slid to 420, the rotational power of the output shaft 220 can be transmitted to the output transmission shaft 910 via the reverse gear 420, the intermediate idle gear 430, and the second gear 930. It has become.
With such a configuration, the transmission 200 can switch forward and backward travel of the traveling vehicle 100.

In addition to the above configuration, the transmission 200 according to the present embodiment further includes a sub-transmission mechanism 500 that performs multi-stage shifting between the output shaft 220 and the output transmission shaft 910.
Specifically, the output transmission shaft 910 is a first output transmission shaft 911 disposed substantially parallel to the output shaft 220, and the first output transmission shaft 911 provided with the first and second gears 920 and 930 is provided. A second output transmission shaft 912 disposed substantially parallel to the shaft 911 and the output shaft 220, the second output transmission shaft being coaxially supported by the first output transmission shaft 911 and rotatably about an axis. 912.

Here, the sub-transmission mechanism 500 is configured to perform a two-speed shift, and includes a sub-transmission mechanism gear transmission mechanism 510 and a sub-transmission mechanism shifter mechanism 520.
The sub-transmission mechanism gear transmission mechanism 510 is configured to transmit power from the first output transmission shaft 911 to the second output transmission shaft 912 at a predetermined transmission ratio (here, a reduction ratio).
Specifically, the sub-transmission mechanism gear transmission mechanism 510 includes a sub-transmission transmission shaft 511 disposed substantially parallel to the output transmission shaft 910 and first and second sub-transmissions having a predetermined reduction ratio. Gear trains 512 and 513 are provided.
Here, the first sub-transmission gear train 512 is in mesh with the first sub-transmission gear 512a, which is provided on the first output transmission shaft 911 so as not to rotate relative to the first sub-transmission gear 512a. A sub-transmission gear 512b, and a second sub-transmission gear 512b provided on the sub-transmission transmission shaft 511 so as not to be relatively rotatable.
The first auxiliary transmission gear 512a and the second auxiliary transmission gear 512b also serve as the second gear 930 and the intermediate idle gear 430, respectively.

The second sub-transmission gear train 513 includes a third sub-transmission gear 513a that is rotatably supported on the second output transmission shaft 912 and a fourth sub-transmission gear that meshes with the third sub-transmission gear 513a. And a fourth sub-transmission gear 513b provided on the sub-transmission transmission shaft 511 so as not to be relatively rotatable.
The sub-transmission mechanism shifter mechanism 520 is provided on the second output transmission shaft 912 so as to be selectively slid between the first output transmission shaft 911 and the third sub-transmission gear 513a. When the first output transmission shaft 911 is slid, the rotational power of the first output transmission shaft 911 is transmitted to the second output transmission shaft 912 and the third sub-transmission gear is used. When sliding on the gear 513a, the rotational power of the first output transmission shaft 911 can be transmitted to the second output transmission shaft 912 via the auxiliary transmission mechanism gear transmission mechanism 510. ing.
By providing such a configuration, the transmission 200 can perform sub-shifting of shifting by the transmission mechanisms 250 and 280 and the hydraulic clutch mechanisms 240 and 270.
Here, the first to eighth shifts can be sub-shifted in two stages, a high speed stage and a low speed stage. For example, when the first speed is set to a low speed, a speed corresponding to the creep speed is set.

In addition to the above configuration, the transmission 200 according to the present embodiment includes a sub-drive transmission mechanism 600 that transmits the rotational drive of the output shaft 220 to the other wheels (here, the front wheels 101 and 101). .
Specifically, the sub-drive transmission mechanism 600 transmits the sub-drive shaft 610 disposed substantially parallel to the second output transmission shaft 912 and the rotational drive of the second output transmission shaft 912 to the sub-drive shaft 610. And a sub-drive shaft gear train 620.
Here, the secondary drive shaft gear train 620 is engaged with the first secondary drive shaft gear 621 and the first secondary drive shaft gear 621 which are provided so as not to rotate relative to the secondary drive shaft 610. A drive shaft gear 622 is provided with a second sub drive shaft gear 622 provided on the second output transmission shaft 912 so as not to be relatively rotatable.

The transmission 200 according to the present embodiment includes a sub-drive speed increasing mechanism 700 that speeds up the rotational drive of the sub-drive transmission mechanism 600 in addition to the above configuration.
Specifically, the sub drive speed increasing mechanism 700 includes a sub drive output shaft 710 disposed substantially parallel to the sub drive shaft 610 and rotation from the sub drive shaft 610 to the sub drive output shaft 710. A first gear train 720 capable of transmitting power at a predetermined speed ratio, and a predetermined increase in which rotational power from the sub drive shaft 610 to the sub drive output shaft 710 can be obtained at a speed higher than the predetermined speed ratio. The second gear train 730 capable of transmitting at a speed ratio and the rotational power of the auxiliary drive shaft 610 selectively to the auxiliary drive output shaft 710 between the first gear train 720 and the second gear train 730. And a shift switching clutch mechanism 740 for transmission.

  The shift switching clutch mechanism 740 selectively transmits the rotational power of the sub drive shaft 610 to the sub drive output shaft 710 between the first gear train 720 and the second gear train 730. Here, the auxiliary drive output shaft 710 is provided.

Specifically, the first gear train 720 includes a first gear 721 that is rotatably supported on the auxiliary drive output shaft 710 and a second gear 722 that meshes with the first gear 721, And a second gear 722 provided on the drive shaft 610 so as not to be relatively rotatable.
The second gear train 730 includes a first speed-increasing gear 731 that is rotatably supported on the auxiliary driving output shaft 710 and a second speed-up gear 732 that meshes with the first speed-increasing gear 731. The auxiliary drive shaft 610 is provided with a second speed-up gear 732 provided so as not to rotate relative to the auxiliary drive shaft 610.
The shift switching clutch mechanism 740 rotates the auxiliary drive shaft 610 by engaging the piston 742 with the engaging portion 721a of the first gear 721 by the urging force of an urging member 741 (here, a coil spring). A first power transmission state in which power is transmitted to the sub-drive output shaft 710 via the second gear 722 and the first gear 721, and a pair of first frictions when hydraulic oil is supplied to the oil chamber 743. The friction surfaces of the plates 744 and 745 are frictionally engaged with each other, so that the rotational power of the auxiliary drive shaft 610 is transmitted to the auxiliary drive shaft via the second acceleration gear 732 and the first acceleration gear 731. It is comprised so that the 2nd power transmission state transmitted to the output shaft 710 can be taken.
By providing such a configuration, the transmission 200 can increase the rotational drive of the auxiliary drive transmission mechanism 600.

In the present embodiment described above, the input shaft 210 is a single one. Instead, the input shaft 210 is a first and second input shaft operatively connected to the drive source 105, and is substantially parallel to each other. It is good also as the 1st and 2nd input shaft arrange | positioned by.
In this case, the first input shaft is disposed in the first transmission path 200a, the second input shaft is disposed in the second transmission path 200b, and the first transmission path 200a is The second transmission path 200b is a transmission path from the first input shaft to the output shaft 220, and the second transmission path 200b is a transmission path from the second input shaft to the output shaft 220.

FIG. 1 is a schematic side view showing a traveling vehicle to which a transmission according to the present embodiment is applied. FIG. 2 is a side view showing a partially developed transmission according to the present embodiment. 3 is an enlarged side view showing the transmission shown in FIG. FIG. 4 is a graph showing temporal changes in the hydraulic pressure supplied from the hydraulic mechanism to the first hydraulic clutch mechanism and the second hydraulic clutch mechanism during the shifting operation.

Explanation of symbols

102, 102 ... Drive wheel 105 ... Drive source 200 ... Transmission
200a ... 1st transmission path 200b ... 2nd transmission path 210 ... Input shaft 220 ... Output shaft
230 ... 1st transmission shaft 240 ... 1st hydraulic clutch mechanism 250 ... 1st speed change mechanism
251 ... A plurality of gear trains for the first transmission mechanism 252 ... First operation mechanism member for the transmission mechanism
260 ... second transmission shaft 270 ... second hydraulic clutch mechanism 280 ... second transmission mechanism
281 ... A plurality of gear trains for the second speed change mechanism 282 ... An operation member for the second speed change mechanism

Claims (6)

A transmission that is inserted in a traveling system transmission path from a driving source to driving wheels,
A single input shaft operatively coupled to the drive source;
An output shaft;
A first transmission shaft arranged to form a first transmission path from the input shaft to the output shaft;
A first hydraulic clutch mechanism disposed in the first transmission path, wherein the first hydraulic clutch mechanism selectively transmits power of the first transmission shaft to the output shaft based on an external operation;
A first transmission mechanism disposed in the first transmission path, wherein the first transmission mechanism performs a multi-speed shift in the first transmission path based on an external operation;
A second transmission shaft disposed from the input shaft to the output shaft so as to constitute a second transmission route different from the first transmission route;
A second hydraulic clutch mechanism disposed in the second transmission path, wherein the second hydraulic clutch mechanism selectively transmits the power of the second transmission shaft to the output shaft based on an external operation;
A transmission comprising: a second speed change mechanism disposed in the second transmission path, wherein the second speed change mechanism performs a multi-speed shift in the second transmission path based on an external operation.   The first speed change mechanism performs multi-stage speed change between the input shaft and the first transmission shaft based on an external operation, and the second speed change mechanism is based on an external operation, the input shaft and the second power transmission shaft. The transmission according to claim 1, wherein a multi-stage shift is performed between the two. The first transmission mechanism includes a plurality of first transmission mechanism gear trains having different transmission ratios, and a first transmission mechanism operation member that selects any one of the plurality of first transmission mechanism gear trains. Have
The second transmission mechanism is one of a plurality of second transmission mechanism gear trains having the same transmission ratio as each of the plurality of first transmission gear trains, and the plurality of second transmission mechanism gear trains. An operation member for a second speed change mechanism that selects one gear,
The first hydraulic clutch mechanism is configured to transmit power from the first transmission shaft to the output shaft at a first gear ratio,
The second hydraulic clutch mechanism is configured to transmit power from the second transmission shaft to the output shaft at a second speed ratio different from the first speed ratio. 2. The transmission according to 2.   The gear provided on the input shaft so as not to rotate relative to the input shaft is configured to act as a drive-side gear in both the first transmission mechanism gear train and the second transmission mechanism gear train. Item 4. The transmission according to Item 3. A transmission that is inserted in a traveling system transmission path from a driving source to driving wheels,
First and second input shafts operatively connected to the drive source;
An output shaft;
A first transmission shaft arranged to form a first transmission path from the first input shaft to the output shaft;
A first hydraulic clutch mechanism disposed in the first transmission path, wherein the first hydraulic clutch mechanism selectively transmits power of the first transmission shaft to the output shaft based on an external operation;
A first transmission mechanism disposed in the first transmission path, wherein the first transmission mechanism performs a multi-speed shift in the first transmission path based on an external operation;
A second transmission shaft arranged to form a second transmission path from the second input shaft to the output shaft;
A second hydraulic clutch mechanism disposed in the second transmission path, wherein the second hydraulic clutch mechanism selectively transmits the power of the second transmission shaft to the output shaft based on an external operation;
A transmission comprising: a second speed change mechanism disposed in the second transmission path, wherein the second speed change mechanism performs a multi-speed shift in the second transmission path based on an external operation.   The transmission mechanism in one transmission path of the first transmission path and the second transmission path is brought into an engagement state of a shift stage according to the first external operation, and the transmission mechanism in the other transmission path is brought into a disengagement state. When the hydraulic clutch mechanism in the one transmission path is set in the power transmission state and the hydraulic clutch mechanism in the other transmission path is set in the power cutoff state, and then the next second external operation is performed, in the one transmission path, While the transmission mechanism is in the engaged state of the shift stage according to the first external operation, the transmission mechanism in the other transmission path is brought into the engaged state of the shift stage in accordance with the second external operation, The hydraulic clutch mechanism in the transmission path is gradually shifted from the power transmission state to the power cutoff state, and at the same time, the hydraulic clutch mechanism in the other transmission path is gradually powered off. Transmission according to any one of claims 1 to 5, characterized in that it is configured to shift to the power transmitting state from.

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