JP5837471B2 - Power transmission device for vehicle - Google Patents

Description

  The present invention relates to a vehicle power transmission device that is mounted on a work vehicle such as a wheel loader or a wheeled excavator and transmits the rotation of a prime mover to an output shaft for traveling.

  In general, a wheel-type work vehicle represented by a wheel loader, a wheel-type excavator, etc. travels on a general road toward a work site by rotationally driving wheels. In this case, the wheel-type work vehicle drives a hydraulic motor by an engine (prime mover), transmits the rotation of the hydraulic motor to the wheel, and transmits the rotation of the engine to the wheel via a power transmission device including a torque converter. There is something to communicate.

  A work vehicle that transmits engine rotation to wheels via a power transmission device is usually provided with a power transmission device that includes a speed change mechanism between the engine and the wheels, and the power transmission device allows the work vehicle to travel forward. It is configured to switch between reverse travel, travel speed, and the like. In this case, in order to promote a reduction in fuel consumption when the work vehicle is traveling, it is desirable that the power transmission device for the vehicle includes as many shift stages (for example, six forward speeds) as possible.

  On the other hand, the power transmission device is usually equipped with a hydraulic pump such as a main pump or a charging pump that supplies pressure oil to a hydraulic actuator mounted on a work vehicle, and this hydraulic pump is driven by an engine. (See Patent Document 1).

Japanese National Patent Publication No. 10-500195

  By the way, the arrangement of the hydraulic pump with respect to the power transmission device includes a configuration in which the output shaft of the prime mover and the input shaft of the hydraulic pump are arranged on the same axis (center PTO), and the output shaft of the prime mover and the input shaft of the hydraulic pump. In the conventional technique described above, the output shaft of the prime mover and the input shaft of the hydraulic pump are disposed on the same axis line.

  However, as the number of auxiliary equipment attached to the engine increases according to exhaust gas emission regulations, the installation space for the power transmission device inside the vehicle body tends to be narrowed, and the output shaft of the prime mover and the input shaft of the hydraulic pump are the same. It may be difficult to arrange on the axis. In this case, the hydraulic pump needs to be compactly attached to the power transmission device by arranging the output shaft of the prime mover and the input shaft of the hydraulic pump in parallel. When the output shaft of the prime mover and the input shaft of the hydraulic pump are disposed in parallel, an arrangement space around the output shaft of the prime mover is required to avoid interference with the cab.

  On the other hand, in the above-described prior art, it is difficult to secure a space for arranging the input shaft of the hydraulic pump in parallel with the input shaft around the input shaft of the power transmission device due to the configuration of the shaft. There is a problem that.

  Furthermore, in the above-described prior art, a plurality of clutches constituting the power transmission device are provided for each one shaft. As a result, the number of shafts and the number of bearings supporting the shafts increase, and the number of parts of the power transmission device increases, resulting in an increase in the number of assembly steps and an increase in manufacturing costs.

  The present invention has been made in view of the above-described problems of the prior art, and can secure a large space for arranging the hydraulic pump around the input shaft and reduce the number of components. The purpose is to provide a power transmission device.

  In order to solve the above-described problems, the present invention provides an input shaft that is rotated by a prime mover mounted on a vehicle, an output shaft that outputs rotation to wheels of the vehicle, and a plurality of transmissions that transmit rotation of the input shaft to the output shaft. The intermediate shaft is applied to a vehicle power transmission device.

  The invention according to claim 1 is characterized in that the intermediate shaft has a forward traveling shaft for transmitting the rotation of the input shaft, and a first-stage shift for shifting the rotation of the forward shaft and transmitting it to the output shaft. The input shaft is provided with an input shaft fixed gear fixed to the input shaft, and the forward shaft is provided with a forward shaft fixed gear fixed to the forward shaft, The input shaft fixed gear and the forward shaft fixed gear directly mesh with each other to transmit the rotation of the input shaft to the forward shaft, and the forward shaft is selectively a low speed gear with respect to the forward shaft. And a high speed clutch that selectively connects a high speed gear to the forward shaft is provided coaxially, and the first speed change shaft and the next speed change shaft are shifted with respect to the speed change shaft. Shifting clutch that selectively connects gears And at least one transmission shaft fixed gear fixed to the transmission shaft, and the forward shaft is a transmission shaft fixed gear provided on the low speed gear of the low speed clutch and the first stage transmission shaft. Or transmission of rotation to the first stage transmission shaft by meshing with a high speed gear of the high speed clutch and a transmission shaft fixed gear provided on the first stage transmission shaft, the first stage transmission shaft is The transmission gear of the transmission clutch provided on the first stage transmission shaft meshes with the transmission shaft fixed gear provided on the next stage transmission shaft, or the transmission shaft fixed gear provided on the first stage transmission shaft and the next stage transmission. The rotation is transmitted to the next-stage transmission shaft by meshing with a transmission gear of a transmission clutch provided on the shaft, and the next-stage transmission shaft includes an output shaft fixed gear fixed to the output shaft and the next In that a structure for transmitting the rotation to the output shaft by meshing with the transmission shaft fixed gear provided on the transmission shaft.

  According to a second aspect of the present invention, the forward shaft is disposed on a circumference centered on the input shaft, and the first-stage transmission shaft is disposed on a circumference centered on the forward shaft.

  According to a third aspect of the present invention, a reverse shaft for reverse travel is provided in a state of being arranged in parallel with the forward shaft, and a reverse clutch for selectively connecting a reverse gear to the reverse shaft is provided on the reverse shaft. A reverse shaft fixed gear fixed to the reverse shaft is provided, the reverse shaft fixed gear meshes with a forward shaft fixed gear fixed to the forward shaft, and the reverse gear of the reverse clutch is the first stage transmission shaft. In other words, the gear is fixed to the transmission shaft fixed gear.

  According to a fourth aspect of the present invention, the input shaft is provided with a reverse clutch that selectively connects a reverse gear to the input shaft, and the reverse gear is the transmission shaft fixed gear of the first stage transmission shaft. It is in the structure which meshes with.

  In a fifth aspect of the invention, a reverse shaft for reverse travel is provided in a state of being arranged in parallel with the forward shaft, and the rotation of the input shaft is reversed and transmitted to the reverse shaft in a state of being arranged in parallel with the forward shaft. A reverse shaft is provided, and the reverse shaft is provided with a reverse clutch for selectively connecting a reverse gear to the reverse shaft, a reverse shaft fixed gear fixed to the reverse shaft is provided, and the reverse shaft is provided with the reverse shaft. Is provided with a reverse shaft fixed gear fixed to the reverse shaft, and the reverse shaft fixed gear meshes with the input shaft fixed gear fixed to the input shaft and the reverse shaft fixed gear to reverse the reverse clutch. The gear is configured to mesh with the transmission shaft fixed gear of the first stage transmission shaft.

  According to the first aspect of the present invention, the low speed clutch and the high speed clutch are provided coaxially with respect to the forward shaft, and the rotation of the forward shaft is transmitted to the first-stage transmission shaft, thereby transmitting the rotation from the input shaft to the output shaft. The plurality of power transmission paths always pass through the first-stage transmission shaft. For this reason, the forward shaft and the next-stage transmission shaft can be collectively arranged around the first-stage transmission shaft, and accordingly, a large space for mounting the hydraulic pump around the input shaft can be secured. As a result, with the input shaft of the hydraulic pump arranged in parallel with the output shaft of the prime mover, the hydraulic pump can be attached to the vehicle power transmission device with a margin, increasing the degree of freedom in designing the vehicle power transmission device. Can do.

  Further, since the two clutches of the low speed clutch and the high speed clutch are provided coaxially with respect to the forward shaft, for example, one shaft is reduced compared to the case where the low speed clutch and the high speed clutch are separately provided on different shafts. And the number of bearings supporting the shaft can be reduced. Thereby, since the number of parts of the vehicle power transmission device can be reduced and the number of assembly steps of the vehicle power transmission device can be reduced, the manufacturing cost can be reduced.

  Further, since the input shaft fixed gear and the forward shaft fixed gear are directly meshed with each other, the rotation of the input shaft can be directly transmitted to the forward shaft without interposing a clutch or the like. It can be rotated smoothly.

  According to the second aspect of the present invention, the forward movement shaft is rotationally displaced on the circumference centered on the input shaft, and the first stage speed change shaft is rotationally displaced on the circumference centered on the forward movement axis, thereby moving forward. The layout of the shaft, the first-stage transmission shaft, and the next-stage transmission shaft can be changed as appropriate. As a result, a large space for mounting the hydraulic pump can be secured around the input shaft, and the degree of design freedom when the hydraulic pump is attached to the power transmission device can be further increased.

  According to the invention of claim 3, the reverse shaft can be rotated in the direction opposite to the forward shaft by meshing the forward shaft fixed gear and the reverse shaft fixed gear. In this state, the reverse gear is connected to the reverse shaft by the reverse clutch, and the reverse gear and the transmission shaft fixed gear of the initial transmission shaft are engaged with each other, whereby the primary transmission shaft is rotated in the reverse direction and the output shaft is rotated. It can be rotated in the reverse direction.

  According to the fourth aspect of the present invention, the reverse gear is connected to the input shaft by the reverse clutch, and the reverse gear and the transmission shaft fixed gear of the initial transmission shaft are engaged with each other, so that the primary transmission shaft is rotated in the reverse direction. And the output shaft can be rotated in the reverse direction. In this case, by providing the reverse clutch on the input shaft, the reverse shaft for providing the reverse clutch can be eliminated, so that the number of parts of the vehicle power transmission device can be further reduced. Further, the degree of design freedom when the hydraulic pump is attached to the power transmission device can be further increased.

  According to the invention of claim 5, the reverse shaft fixed gear fixed to the reverse shaft is engaged with the input shaft fixed gear and the reverse shaft fixed gear to rotate the reverse shaft in the direction opposite to the forward shaft. Can do. In this state, the reverse gear is connected to the reverse shaft by the reverse clutch, and the reverse gear and the transmission shaft fixed gear of the initial transmission shaft are engaged with each other, whereby the primary transmission shaft is rotated in the reverse direction and the output shaft is rotated. It can be rotated in the reverse direction. In this case, the input shaft, the forward shaft, the reverse shaft, the reverse shaft, and the first-stage transmission shaft are in a state where five bead chains are connected, so the distance between the input shaft and the first-stage transmission shaft should be set with a large width. Can do. As a result, the degree of freedom in design can be increased in response to a request for increasing the distance between the input shaft and the output shaft.

It is a front view which shows the wheel loader carrying the power transmission device for vehicles which concerns on this invention. It is a schematic block diagram which shows the axis | shaft, gearwheel, clutch, etc. which comprise the vehicle power transmission device by 1st Embodiment. FIG. 3 is an arrangement diagram of shafts and gears in FIG. 2. It is a 1st modification which shows other arrangement | positioning of the axis | shaft and gearwheel by 1st Embodiment. It is a schematic block diagram which shows the axis | shaft, gearwheel, clutch, etc. which comprise the vehicle power transmission device by 2nd Embodiment. FIG. 6 is an arrangement diagram of shafts and gears in FIG. 5. It is the 2nd modification which shows other arrangement | positioning of the axis | shaft and gearwheel by 2nd Embodiment. It is a schematic block diagram which shows the axis | shaft, gearwheel, clutch, etc. which comprise the vehicle power transmission device by 3rd Embodiment. FIG. 9 is a layout diagram of shafts and gears in FIG. 8. It is the 3rd modification which shows other arrangement | positioning of the axis | shaft and gearwheel by 3rd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a vehicle power transmission device according to the present invention will be described in detail with reference to the accompanying drawings.

  First, FIG. 1 to FIG. 4 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a wheel loader as a representative example of a wheel type work vehicle. In this wheel loader 1, a front vehicle body 3 provided with left and right front wheels 2 and a rear vehicle body 5 provided with left and right rear wheels 4 are connected in a left and right direction via a coupling mechanism 6. It is connected to bendable. The wheel loader 1 is configured as an articulated work vehicle that performs steering by bending the front vehicle body 3 and the rear vehicle body 5 in the left and right directions by the steering cylinder 7.

  Here, the front body 3 of the wheel loader 1 is provided with a working device 8 including a loader bucket 8A so as to be able to move up and down. On the other hand, a cab 9 defining a cab, an engine 10 as a prime mover, a vehicle power transmission device 21 described later, and the like are mounted on the rear vehicle body 5 of the wheel loader 1.

  A front axle (front axle) 11 extending in the left and right directions is provided below the front vehicle body 3, and left and right front wheels 2 are attached to both ends of the front axle 11. . On the other hand, a rear axle (rear axle) 12 extending in the left and right directions is provided below the rear vehicle body 5, and left and right rear wheels 4 are attached to both ends of the rear axle 12. The front axle 11 is connected to an output shaft 49 of a power transmission device 21 described later via a propeller shaft 13, and the rear axle 12 is connected to an output shaft 49 of the power transmission device 21 via a propeller shaft 14. .

  Next, the power transmission device 21 used in the first embodiment will be described.

  That is, 21 indicates a power transmission device mounted on the rear vehicle body 5 of the wheel loader 1. As shown in FIG. 1, the power transmission device 21 is connected to the engine 10, and changes the rotational output of the engine 10 and transmits it to the front axle 11 and the rear axle 12. This power transmission device 21 is configured to be able to perform six-speed switching from the first speed to the sixth speed during forward travel and to perform three-speed speed switching from the first speed to the third speed during reverse travel. Yes.

  Here, the power transmission device 21 includes a torque converter 23, an input shaft 24, a forward shaft 26, a reverse shaft 30, a first transmission shaft 33, a second transmission shaft 41, and a third transmission shaft, which will be described later, provided in the casing 22. 46, output shaft 49, clutches 28, 29, 32, 40, 45, 48, gears 25, 27, 28A, 29A, 31, 32A, 34, 35, 36, 40A, 42, 43, 45A, 47, 48A, 50, etc.

  Reference numeral 23 denotes a torque converter, which is connected to a crankshaft (not shown) of the engine 10 and transmits the rotational output of the engine 10 to an input shaft 24 described later using oil.

  Reference numeral 24 denotes an input shaft that is rotated by the engine 10, and the input shaft 24 transmits the rotational output of the engine 10 via the torque converter 23. Here, the input shaft 24 is provided with an input shaft fixing gear 25 fixed to the input shaft 24, and the input shaft fixing gear 25 meshes with a forward shaft fixing gear 27 described later.

  Reference numeral 26 denotes a forward shaft arranged in parallel below the input shaft 24. The forward shaft 26 is provided with a forward shaft fixed gear 27 fixed to the forward shaft 26, and the forward shaft fixed gear 27 meshes with the input shaft fixed gear 25. Accordingly, the forward shaft 26 always rotates together with the input shaft 24.

  A low speed clutch 28 and a high speed clutch 29 are coaxially provided on the forward shaft 26. The low speed clutch 28 is disposed between a low speed gear 28A provided rotatably with respect to the forward shaft 26 and the forward shaft 26, and the low speed gear 28A is selected with respect to the forward shaft 26 by supplying and discharging the clutch pressure. Connected. On the other hand, the high-speed clutch 29 is disposed between a high-speed gear 29A provided rotatably with respect to the forward shaft 26 and the forward shaft 26, and the high-speed gear 29A with respect to the forward shaft 26 by supplying and discharging the clutch pressure. Are selectively connected.

  Reference numeral 30 denotes a reverse shaft disposed below the input shaft 24 in parallel with the forward shaft 26. The reverse shaft 30 is provided with a reverse shaft fixed gear 31 fixed to the reverse shaft 30, and the reverse shaft fixed gear 31 meshes with the forward shaft fixed gear 27. Accordingly, the reverse shaft 30 always rotates together with the input shaft 24.

  Reference numeral 32 denotes a reverse clutch provided on the reverse shaft 30, and the reverse clutch 32 is disposed between the reverse gear 32 </ b> A provided rotatably with respect to the reverse shaft 30 and the reverse shaft 30. The reverse clutch 32 selectively connects the reverse gear 32A to the reverse shaft 30 by supplying and discharging clutch pressure.

  Next, the arrangement relationship and structure of the first transmission shaft 33 as the first-stage transmission shaft will be described.

  That is, reference numeral 33 denotes a first transmission shaft as a first-stage transmission shaft arranged in parallel with the forward shaft 26 and the reverse shaft 30 below. As shown in FIG. 3, the first transmission shaft 33 is surrounded by a forward shaft 26, a reverse shaft 30, a second transmission shaft 41, which will be described later, and a third transmission shaft 46. The first transmission shaft 33 shifts the rotation of the forward shaft 26 or the reverse shaft 30 and transmits it to the second transmission shaft 41 or the third transmission shaft 46.

  Here, the first speed change shaft 33 is provided with three first speed change shaft fixing gears 34, 35, 36 fixed at intervals in the axial direction, and these three first speed change shaft fixing gears 34, 35 are provided. , 36 have different numbers of teeth. In this case, the first transmission shaft fixed gear 34 meshes with the low speed gear 28A of the low speed clutch 28 as shown by a broken line 37 in FIG. 2 and is described later as shown by a broken line 38 in FIG. The third speed change gear 48 is engaged with the third speed change gear 48A. Further, the first transmission shaft fixed gear 36 meshes with the high speed gear 29A of the high speed clutch 29 as indicated by a broken line 39 in FIG.

  Reference numeral 40 denotes a first speed change clutch provided on the first speed change shaft 33. The first speed change clutch 40 and the first speed change gear 40A provided to be rotatable with respect to the first speed change shaft 33 and the first speed change gear. It is arranged between the shaft 33. The first speed change clutch 40 selectively connects the first speed change gear 40A to the first speed change shaft 33 by supplying and discharging clutch pressure.

  Next, the arrangement relationship and structure of the second transmission shaft 41 and the third transmission shaft 46 as the next-stage transmission shaft will be described.

  Reference numeral 41 denotes a second transmission shaft as a next-stage transmission shaft arranged in parallel to the lower side of the first transmission shaft 33, and the second transmission shaft 41 changes the rotation of the first transmission shaft 33. Is. Here, the second speed change shaft 41 is provided with two second speed change shaft fixing gears 42 and 43 fixed to the second speed change shaft 41 with an interval in the axial direction. The transmission shaft fixed gears 42 and 43 have different numbers of teeth. In this case, the second transmission shaft fixed gear 42 meshes with the first transmission gear 40A of the first transmission clutch 40, and the second transmission shaft fixed gear 43 will be described later, as indicated by a broken line 44 in FIG. The gear is engaged with the output shaft fixing gear 50.

  Reference numeral 45 denotes a second speed change clutch provided on the second speed change shaft 41. The second speed change clutch 45 and the second speed change gear 45A provided to be rotatable with respect to the second speed change shaft 41 and the second speed change gear. It is arranged between the shaft 41. The second speed change clutch 45 selectively connects the second speed change gear 45A to the second speed change shaft 41 by supplying and discharging clutch pressure.

  Reference numeral 46 denotes a third transmission shaft as a next-stage transmission shaft arranged in parallel to the lower side of the first transmission shaft 33. The third transmission shaft 46 is a second transmission shaft with the first transmission shaft 33 interposed therebetween. It is arrange | positioned on the opposite side to the transmission shaft 41, and changes the rotation of the 1st transmission shaft 33. As shown in FIG. Here, the third transmission shaft 46 is provided with one third transmission shaft fixing gear 47 fixed to the third transmission shaft 46, and the third transmission shaft fixing gear 47 is fixed to the output shaft fixing. It meshes with the gear 50.

  Reference numeral 48 denotes a third speed change clutch provided on the third speed change shaft 46, and the third speed change clutch 48 and a third speed change gear 48 </ b> A provided to be rotatable with respect to the third speed change shaft 46. It is arranged between the shaft 46. The third speed change clutch 48 selectively connects the third speed change gear 48A to the third speed change shaft 46 by supplying and discharging clutch pressure.

  Reference numeral 49 denotes an output shaft arranged below each of the transmission shafts 33, 41, 46. The output shaft 49 transmits the rotations changed by the transmission shafts 33, 41, and 46 to the front axle 11 and the rear axle 12 of the wheel loader 1 through the propeller shafts 13 and 14 shown in FIG. .

  Here, the output shaft 49 is provided with one output shaft fixed gear 50 fixed to the output shaft 49. The output shaft fixed gear 50 includes a second transmission shaft fixed gear 43 and a third gear. It meshes with the transmission shaft fixed gear 47.

  Thus, the power transmission device 21 according to the first embodiment has the intermediate shaft for transmitting the rotation of the input shaft 24 to the output shaft 49 as the forward shaft 26, the reverse shaft 30, and the first transmission shaft 33 (first stage). (Transmission shaft), the second transmission shaft 41, and the third transmission shaft 46 (next-stage transmission shaft).

  The power transmission device 21 according to the first embodiment has the above-described configuration. Hereinafter, the speed change operation of the power transmission device 21 when the wheel loader 1 is traveling will be described.

  First, the 1st to 6th speed shifting operation when the wheel loader 1 travels forward will be described.

  When the engine 10 operates, the rotational output of the engine 10 is transmitted to the input shaft 24 via the torque converter 23, and the input shaft 24 rotates together with the input shaft fixed gear 25. As a result, the forward shaft 26 having the forward shaft fixed gear 27 that meshes with the input shaft fixed gear 25 rotates.

  Here, when the wheel loader 1 travels forward at the first speed, the low speed clutch 28 is connected to the forward shaft 26 and the first transmission clutch 40 is connected to the first transmission shaft 33. As a result, the low speed gear 28 </ b> A rotates integrally with the forward shaft 26, and the rotation of the low speed gear 28 </ b> A is transmitted to the first transmission shaft 33 via the first transmission shaft fixed gear 34.

  At this time, since the first transmission clutch 40 is connected to the first transmission shaft 33, the first transmission gear 40 </ b> A rotates integrally with the first transmission shaft 33. The rotation of the first transmission gear 40 </ b> A is transmitted to the second transmission shaft 41 via the second transmission shaft fixed gear 42. As a result, the second transmission shaft fixed gear 43 rotates, and the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixed gear 27, the low speed gear 28A of the low speed clutch 28, the first transmission shaft fixed gear 34, the first transmission gear 40A of the first transmission clutch 40, the second transmission fixed gears 42 and 43, the output The rotation of the input shaft 24 is transmitted to the output shaft 49 through the shaft fixing gear 50 or the like, and the output shaft 49 can be rotated in the forward direction at the first speed.

  Next, when the wheel loader 1 travels forward at the second speed, the high speed clutch 29 is connected to the forward shaft 26 and the first transmission clutch 40 is connected to the first transmission shaft 33. As a result, the high speed gear 29 </ b> A rotates integrally with the forward shaft 26, and the rotation of the high speed gear 29 </ b> A is transmitted to the first transmission shaft 33 via the first transmission shaft fixed gear 36.

  At this time, since the first speed change clutch 40 is connected to the first speed change shaft 33, the first speed change gear 40A rotates together with the first speed change shaft 33, and the rotation of the first speed change gear 40A is rotated. The second transmission shaft 41 is transmitted to the second transmission shaft 41 via the second transmission shaft fixed gear 42. As a result, the second transmission shaft fixed gear 43 rotates, and the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixed gear 27, the high speed gear 29A of the high speed clutch 29, the first transmission shaft fixed gear 36, the first transmission gear 40A of the first transmission clutch 40, the second transmission shaft fixed gears 42 and 43, the output The rotation of the input shaft 24 is transmitted to the output shaft 49 via the shaft fixing gear 50 or the like, and the output shaft 49 can be rotated in the forward direction at the second speed.

  Next, when the wheel loader 1 travels forward at the third speed, the low speed clutch 28 is connected to the forward shaft 26 and the second speed change clutch 45 is connected to the second speed change shaft 41. As a result, the low speed gear 28A rotates integrally with the forward shaft 26, and the rotation of the low speed gear 28A is transmitted to the first transmission shaft 33 via the first transmission shaft fixing gear 34, thereby fixing the first transmission shaft. The gear 35 rotates.

  At this time, since the second transmission clutch 45 is connected to the second transmission shaft 41, the rotation of the first transmission shaft fixed gear 35 is transmitted to the second transmission shaft 41 via the second transmission gear 45A. . As a result, the second transmission shaft fixed gear 43 rotates, and the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixed gear 27, the low speed gear 28A of the low speed clutch 28, the first transmission shaft fixed gears 34 and 35, the second transmission gear 45A of the second transmission clutch 45, the second transmission shaft fixed gear 43, the output The rotation of the input shaft 24 is transmitted to the output shaft 49 through the shaft fixing gear 50 and the like, and the output shaft 49 can be rotated in the forward direction at the third speed.

  Next, when the wheel loader 1 travels forward at the fourth speed, the high speed clutch 29 is connected to the forward shaft 26 and the second speed change clutch 45 is connected to the second speed change shaft 41. As a result, the high speed gear 29A rotates integrally with the forward shaft 26, and the rotation of the high speed gear 29A is transmitted to the first transmission shaft 33 via the first transmission shaft fixing gear 36, thereby fixing the first transmission shaft. The rotation of the gear 35 is transmitted to the second speed change gear 45 </ b> A of the second speed change clutch 45.

  At this time, since the second transmission clutch 45 is connected to the second transmission shaft 41, the rotation of the second transmission gear 45A is transmitted to the second transmission shaft 41. As a result, the second transmission shaft fixed gear 43 rotates, and the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixed gear 27, the high speed gear 29A of the high speed clutch 29, the first transmission shaft fixed gears 36 and 35, the second transmission gear 45A of the second transmission clutch 45, the second transmission shaft fixed gear 43, the output The rotation of the input shaft 24 is transmitted to the output shaft 49 through the shaft fixing gear 50 or the like, and the output shaft 49 can be rotated in the forward direction at the fourth speed.

  Next, when the wheel loader 1 travels forward at the fifth speed, the low speed clutch 28 is connected to the forward shaft 26 and the third speed change clutch 48 is connected to the third speed change shaft 46. As a result, the low speed gear 28A rotates integrally with the forward shaft 26, and the rotation of the low speed gear 28A is transmitted to the third transmission gear 48A of the third transmission clutch 48 via the first transmission shaft fixed gear 34. Is done.

  At this time, since the third transmission clutch 48 is connected to the third transmission shaft 46, the rotation of the third transmission gear 48 </ b> A is transmitted to the third transmission shaft 46. As a result, the third transmission shaft fixed gear 47 rotates, and the rotation of the third transmission shaft fixed gear 47 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixed gear 27, the low speed gear 28A of the low speed clutch 28, the first transmission shaft fixed gear 34, the third transmission gear 48A of the third transmission clutch 48, the third transmission shaft fixed gear 47, the output shaft fixed. The rotation of the input shaft 24 is transmitted to the output shaft 49 through the gear 50 and the like, and the output shaft 49 can be rotated in the forward direction at the fifth speed.

  Next, when the wheel loader 1 travels forward at the sixth speed, the high speed clutch 29 is connected to the forward shaft 26 and the third speed change clutch 48 is connected to the third speed change shaft 46. As a result, the high speed gear 29A rotates integrally with the forward shaft 26, and the rotation of the high speed gear 29A is transmitted to the first transmission shaft 33 via the first transmission shaft fixing gear 36, thereby fixing the first transmission shaft. The rotation of the gear 34 is transmitted to the third speed change gear 48 </ b> A of the third speed change clutch 48.

  At this time, since the third transmission clutch 48 is connected to the third transmission shaft 46, the rotation of the third transmission gear 48 </ b> A is transmitted to the third transmission shaft 46. As a result, the third transmission shaft fixed gear 47 rotates, and the rotation of the third transmission shaft fixed gear 47 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixed gear 27, the high speed gear 29A of the high speed clutch 29, the first transmission shaft fixed gears 36 and 34, the third transmission gear 48A of the third transmission clutch 48, the third transmission shaft fixed gear 47, the output The rotation of the input shaft 24 is transmitted to the output shaft 49 through the shaft fixing gear 50 or the like, and the output shaft 49 can be rotated in the forward direction at the sixth speed.

  Next, the shifting operation from the first speed to the third speed when the wheel loader 1 travels backward will be described.

  When the wheel loader 1 travels backward at the first speed, the reverse clutch 32 is connected to the reverse shaft 30 and the first transmission clutch 40 is connected to the first transmission shaft 33. Thus, after the rotation of the input shaft 24 is transmitted to the reverse shaft 30 via the input shaft fixed gear 25, the forward shaft fixed gear 27, and the reverse shaft fixed gear 31, the reverse gear 32A of the reverse clutch 32, the first This is transmitted to the first transmission shaft 33 via the transmission shaft fixed gear 34.

  At this time, since the first speed change clutch 40 is connected to the first speed change shaft 33, the first speed change gear 40A rotates together with the first speed change shaft 33, and the rotation of the first speed change gear 40A is rotated. The second transmission shaft 41 is transmitted to the second transmission shaft 41 via the second transmission shaft fixed gear 42. As a result, the second transmission shaft fixed gear 43 rotates, and the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixed gear 27, the reverse shaft fixed gear 31, the reverse gear 32A, the first transmission shaft fixed gear 34, the first transmission gear 40A of the first transmission clutch 40, and the second transmission fixed gear. The rotation of the input shaft 24 is transmitted to the output shaft 49 through the gears 42 and 43, the output shaft fixed gear 50, etc., and the output shaft 49 can be rotated in the reverse direction at the first speed.

  Next, when the wheel loader 1 travels backward at the second speed, the reverse clutch 32 is connected to the reverse shaft 30 and the second transmission clutch 45 is connected to the second transmission shaft 41. Thus, after the rotation of the input shaft 24 is transmitted to the reverse shaft 30 via the input shaft fixed gear 25, the forward shaft fixed gear 27, and the reverse shaft fixed gear 31, the reverse gear 32A of the reverse clutch 32, the first This is transmitted to the first transmission shaft 33 via the transmission shaft fixed gear 34.

  At this time, since the second speed change clutch 45 is connected to the second speed change shaft 41, the rotation of the first speed change shaft 33 is changed to the second speed change gear via the first speed change shaft fixing gear 35 and the second speed change gear 45A. It is transmitted to the shaft 41. As a result, the second transmission shaft fixed gear 43 rotates, and the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixed gear 27, the reverse shaft fixed gear 31, the reverse gear 32A, the first shift shaft fixed gears 34 and 35, the second speed change gear 45A of the second speed change clutch 45, the second speed change gear. The rotation of the input shaft 24 is transmitted to the output shaft 49 through the shaft fixed gear 43, the output shaft fixed gear 50, etc., and the output shaft 49 can be rotated in the reverse direction at the second speed.

  Next, when the wheel loader 1 travels backward at the third speed, the reverse clutch 32 is connected to the reverse shaft 30 and the third speed change clutch 48 is connected to the third speed change shaft 46. Thus, after the rotation of the input shaft 24 is transmitted to the reverse shaft 30 via the input shaft fixed gear 25, the forward shaft fixed gear 27, and the reverse shaft fixed gear 31, the reverse gear 32A of the reverse clutch 32, the first This is transmitted to the first transmission shaft 33 via the transmission shaft fixed gear 34.

  At this time, since the third speed change clutch 48 is connected to the third speed change shaft 46, the rotation of the first speed change shaft 33 is changed to the third speed change gear via the first speed change shaft fixing gear 34 and the third speed change gear 48A. It is transmitted to the shaft 46. As a result, the third transmission shaft fixed gear 47 rotates, and the rotation of the third transmission shaft fixed gear 47 is transmitted to the output shaft 49 via the output shaft fixed gear 50.

  As a result, the forward shaft fixing gear 27, the reverse shaft fixed gear 31, the reverse gear 32, the reverse gear 32A, the first transmission shaft fixed gear 34, the third transmission gear 48A of the third transmission clutch 48, and the third transmission shaft fixed. The rotation of the input shaft 24 is transmitted to the output shaft 49 via the gear 47, the output shaft fixed gear 50, etc., and the output shaft 49 can be rotated in the reverse direction at the third speed.

  Thus, the power transmission device 21 according to the first embodiment has six types of power transmission paths for transmitting rotation from the input shaft 24 to the output shaft 49 during forward traveling from the first speed to the sixth speed, and the first speed to the third speed. The three types of power transmission paths that transmit the rotation from the input shaft 24 to the output shaft 49 during the reverse travel up to are always configured to pass through the first transmission shaft 33.

  As a result, the forward shaft 26, the reverse shaft 30, the second transmission shaft 41, and the third transmission shaft 46 can be arranged around the first transmission shaft 33, and accordingly, around the input shaft 24. A large space can be secured. That is, as shown in FIG. 3, a fan-like shape is shown with hatching between a high speed gear 29A of a high speed clutch 29 provided on the forward shaft 26 and a reverse shaft fixed gear 31 provided on the reverse shaft 30. Space 51 can be secured. As a result, for example, even when the input shaft (not shown) of the hydraulic pump is disposed in parallel with the output shaft of the engine 10, the hydraulic pump can be disposed in the space 51 with a margin. The degree of freedom of design when attaching to the power transmission device 21 can be increased.

  Here, in the power transmission device 21 according to the first embodiment, the forward shaft 26 is arranged on a circumference centering on the input shaft 24, and the first transmission shaft 33 is on the circumference centering on the forward shaft 26. Is arranged. That is, as shown in FIG. 3, the length of the line segment 52 connecting the axis center of the input shaft 24 and the axis center of the forward shaft 26 is constant, and the axis center of the forward shaft 26, the axis center of the reverse shaft 30, The length of each side of the triangle 53 connecting the shaft center of the first transmission shaft 33 is constant.

  On the other hand, the length of each side of the quadrangle 54 connecting the shaft center of the first transmission shaft 33, the shaft center of the second transmission shaft 41, the shaft center of the third transmission shaft 46, and the shaft center of the output shaft 49 is constant. The distance between the shaft center of the first transmission shaft 33 and the shaft center of the output shaft 49 and the distance between the shaft center of the second transmission shaft 41 and the shaft center of the third transmission shaft 46 can be changed. .

  As a result, for example, as in the first modification shown in FIG. 4, the advance shaft 26 is rotationally displaced on the circumference around the input shaft 24, and the first on the circumference around the advance shaft 26. By rotationally displacing the first transmission shaft 33, the layout of the forward shaft 26, the reverse shaft 30, the first transmission shaft 33, the second transmission shaft 41, and the third transmission shaft 46 can be appropriately changed to transmit power. The degree of freedom when designing the device 21 can be increased.

  As a result, a fan-shaped space covering a wider range than the space 51 shown in FIG. 3 is formed between the high speed gear 29A of the high speed clutch 29 provided on the forward shaft 26 and the reverse shaft fixed gear 31 provided on the reverse shaft 30. 55 can be secured. Therefore, by using this large space 55, the degree of freedom when setting the mounting position of the hydraulic pump with respect to the power transmission device 21 can be increased.

  Further, the power transmission device 21 according to the first embodiment is configured such that two clutches of a low speed clutch 28 and a high speed clutch 29 are provided coaxially with respect to the forward shaft 26. Thereby, for example, compared with the case where the low speed clutch 28 and the high speed clutch 29 are provided separately on different shafts, one shaft can be reduced, and the number of bearings supporting the shaft can also be reduced. Thereby, since the number of parts of the power transmission device 21 can be reduced and the number of assembling steps can be reduced, the manufacturing cost can be reduced.

  Next, FIGS. 5 to 7 show a second embodiment of the present invention, and the feature of the second embodiment is that a reverse clutch is provided on the input shaft. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In the figure, reference numeral 61 denotes a power transmission device according to the second embodiment. This power transmission device 61 is substantially the same as the power transmission device 21 according to the first embodiment. 1 transmission shaft 33, 2nd transmission shaft 41, 3rd transmission shaft 46, output shaft 49, each clutch 28, 29, 40, 45, 48, each gear 25, 27, 28A, 29A, 34, 35, 36, 40A , 42, 43, 45A, 47, 48A, 50, an input shaft 62 described later, a reverse clutch 63, a reverse gear 63A, and the like.

  However, the power transmission device 61 according to the second embodiment is different from the power transmission device 21 according to the first embodiment in that the reverse clutch 63 is provided on the input shaft 62.

  Reference numeral 62 denotes an input shaft. The input shaft 62 is used in the second embodiment instead of the input shaft 24 according to the first embodiment. The input shaft 62 is for transmitting a rotational output of an engine (not shown) via the torque converter 23. Here, the input shaft fixed gear 25 is fixed to the input shaft 62, and the input shaft fixed gear 25 meshes with the forward shaft fixed gear 27 fixed to the forward shaft 26.

  Reference numeral 63 denotes a reverse clutch provided on the input shaft 62, and the reverse clutch 63 is disposed between a reverse gear 63 </ b> A provided rotatably with respect to the input shaft 62 and the input shaft 62. The reverse clutch 63 selectively connects a reverse gear 63A to the input shaft 62 by supplying and discharging clutch pressure. Further, as indicated by a broken line 64 in FIG. 5, the reverse gear 63 </ b> A meshes with the first transmission shaft fixed gear 34 of the first transmission shaft 33.

  Thus, the power transmission device 61 according to the second embodiment eliminates the reverse shaft 30 used in the power transmission device 21 according to the first embodiment by providing the reverse clutch 63 on the input shaft 62. It has a configuration that can.

  The power transmission device 61 according to the second embodiment has the above-described configuration, and the power transmission according to the first embodiment is performed for the speed change operation when the wheel loader 1 travels forward from the first speed to the sixth speed. It is the same as the device 21.

  Therefore, the speed change operation of the power transmission device 61 when the wheel loader 1 travels backward from the first speed to the third speed will be described.

  First, when the wheel loader 1 travels backward at the first speed, the reverse clutch 63 is connected to the input shaft 62 and the first transmission clutch 40 is connected to the first transmission shaft 33. As a result, the rotation of the input shaft 62 is transmitted to the first transmission shaft 33 via the reverse gear 63 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the first transmission clutch 40 is connected to the first transmission shaft 33, the rotation of the first transmission gear 40A is transmitted to the second transmission shaft 41 via the second transmission shaft fixed gear 42. . As a result, the second transmission shaft fixed gear 43 rotates, and the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50, and the output shaft 49 is moved in the reverse direction at the first speed. Can be rotated.

  Next, when the wheel loader 1 travels backward at the second speed, the reverse clutch 63 is connected to the input shaft 62 and the second transmission clutch 45 is connected to the second transmission shaft 41. Accordingly, the rotation of the input shaft 62 is transmitted to the first transmission shaft fixed gear 35 via the reverse gear 63A of the reverse clutch 63, the first transmission shaft fixed gear 34, and the first transmission shaft 33.

  At this time, since the second transmission clutch 45 is connected to the second transmission shaft 41, the rotation of the first transmission shaft fixed gear 35 is transmitted to the second transmission shaft 41 via the second transmission gear 45A. . As a result, the second transmission shaft fixed gear 43 rotates, and the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50, and the output shaft 49 is moved in the reverse direction at the second speed. Can be rotated.

  Next, when the wheel loader 1 travels backward at the third speed, the reverse clutch 63 is connected to the input shaft 62 and the third transmission clutch 48 is connected to the third transmission shaft 46. Thereby, the rotation of the input shaft 62 is transmitted to the third speed change gear 48 </ b> A of the third speed change clutch 48 via the reverse speed gear 63 </ b> A and the first speed change shaft fixed gear 34.

  At this time, since the third transmission clutch 48 is connected to the third transmission shaft 46, the rotation of the third transmission gear 48 </ b> A is transmitted to the third transmission shaft fixed gear 47 through the third transmission shaft 46. Accordingly, the rotation of the third transmission shaft fixed gear 47 is transmitted to the output shaft 49 via the output shaft fixed gear 50, and the output shaft 49 can be rotated in the reverse direction at the third speed.

  Thus, since the power transmission device 61 according to the second embodiment is configured to provide the reverse clutch 63 on the input shaft 62, the reverse shaft 30 used in the power transmission device 21 according to the first embodiment is not required. be able to. Thereby, since the number of parts of the power transmission device 61 can be further reduced and the number of assembly steps can be reduced, the manufacturing cost can be further reduced.

  In addition, the power transmission device 61 eliminates the need for the reverse shaft 30, so that the forward shaft 26, the second transmission shaft 41, and the third transmission shaft 46 are further concentrated around the first transmission shaft 33. And a larger space around the input shaft 62 can be secured. That is, as shown in FIG. 6, hatching is provided between the high speed gear 29A of the high speed clutch 29 provided on the forward shaft 26 and the first transmission shaft fixed gear 34 provided on the first transmission shaft 33. A large fan-shaped space 65 shown in FIG. As a result, the hydraulic pump can be disposed in the space 65 with a margin, and the degree of freedom in design when the hydraulic pump is attached to the power transmission device 61 can be increased.

  Here, in the power transmission device 61 according to the second embodiment, the forward shaft 26 is arranged on a circumference centered on the input shaft 62, and the first transmission shaft 33 is on the circumference centered on the forward shaft 26. Is arranged. That is, as shown in FIG. 6, the length of each side of the triangle 66 that connects the axis center of the input shaft 62, the axis center of the forward movement shaft 26, and the axis center of the first transmission shaft 33 is constant.

  On the other hand, the length of each side of the quadrangle 67 connecting the shaft center of the first transmission shaft 33, the shaft center of the second transmission shaft 41, the shaft center of the third transmission shaft 46, and the shaft center of the output shaft 49 is constant, The distance between the shaft center of the first transmission shaft 33 and the shaft center of the output shaft 49 and the distance between the shaft center of the second transmission shaft 41 and the shaft center of the third transmission shaft 46 can be changed. .

  As a result, for example, as in the second modification shown in FIG. 7, the forward shaft 26 is rotationally displaced on the circumference around the input shaft 62, and the second on the circumference around the forward shaft 26. By rotating and shifting the first transmission shaft 33, a space 68 equivalent to the space 65 shown in FIG. 6 is secured, and the forward shaft 26, the first transmission shaft 33, the second transmission shaft 41, and the third transmission shaft 46 are secured. A layout can be changed suitably and the freedom degree of design of the power transmission device 61 can be raised.

  Next, FIGS. 8 to 10 show a third embodiment of the present invention. The feature of the third embodiment is that a reverse shaft arranged in parallel with the forward shaft is provided and input by this reverse shaft. The shaft rotation is reversed and transmitted to the reverse shaft. Note that in the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In the figure, reference numeral 71 denotes a power transmission device according to the third embodiment. This power transmission device 71 is substantially the same as the power transmission device 21 according to the first embodiment, and the torque converter 23, the input shaft 24, and the forward drive. Shaft 26, reverse shaft 30, first transmission shaft 33, second transmission shaft 41, third transmission shaft 46, output shaft 49, clutches 28, 29, 32, 40, 45, 48, gears 25, 27, 28A , 29A, 31, 32A, 34, 35, 36, 40A, 42, 43, 45A, 47, 48A, 50, a reversing shaft 72, a reversing shaft fixing gear 73, which will be described later, and the like.

  However, the power transmission device 71 according to the third embodiment is configured such that the rotation of the input shaft 24 is reversed by the reverse rotation shaft 72 and transmitted to the reverse shaft 30. Is different.

  Reference numeral 72 denotes a reverse shaft arranged in parallel with the forward shaft 26, and the reverse shaft 72 reverses the rotation of the input shaft 24 and transmits it to the reverse shaft 30. Here, the reverse rotation shaft 72 is provided with a reverse rotation shaft fixing gear 73 fixed to the reverse rotation shaft 72, and the reverse rotation shaft fixing gear 73 meshes with the input shaft fixing gear 25 fixed to the input shaft 24. And meshes with a reverse shaft fixed gear 31 fixed to the reverse shaft 30.

  In the third embodiment, the reverse gear 32A of the reverse clutch 32 meshes with the first transmission shaft fixed gear 34 of the first transmission shaft 33, as indicated by a broken line 74 in FIG. It has become.

  The power transmission device 71 according to the third embodiment has the above-described configuration. Regarding the speed change operation when the wheel loader 1 travels forward from the first speed to the sixth speed, the power transmission according to the first embodiment is performed. It is the same as the device 21.

  Therefore, the speed change operation of the power transmission device 71 when the wheel loader 1 travels backward from the first speed to the third speed will be described.

  First, when the wheel loader 1 travels backward at the first speed, the reverse clutch 32 is connected to the reverse shaft 30 and the first transmission clutch 40 is connected to the first transmission shaft 33. As a result, the rotation of the input shaft 24 causes the first speed change via the input shaft fixed gear 25, the reverse shaft fixed gear 73, the reverse shaft fixed gear 31, the reverse gear 32A, the reverse gear 32A, and the first transmission shaft fixed gear 34. It is transmitted to the shaft 33.

  At this time, since the first transmission clutch 40 is connected to the first transmission shaft 33, the rotation of the first transmission gear 40A is transmitted to the second transmission shaft 41 via the second transmission shaft fixed gear 42. . Thus, the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50, and the output shaft 49 can be rotated in the reverse direction at the first speed.

  Next, when the wheel loader 1 travels backward at the second speed, the reverse clutch 32 is connected to the reverse shaft 30 and the second transmission clutch 45 is connected to the second transmission shaft 41. Thereby, the rotation of the input shaft 24 is changed via the input shaft fixed gear 25, the reverse shaft fixed gear 73, the reverse shaft fixed gear 31, the reverse gear 32A, the reverse gear 32A, and the first transmission shaft fixed gears 34 and 35. It is transmitted to the second gear 45A of the two-speed clutch 45.

  At this time, since the second transmission clutch 45 is connected to the second transmission shaft 41, the rotation of the second transmission gear 45A is transmitted to the second transmission shaft fixed gear 43. Thus, the rotation of the second transmission shaft fixed gear 43 is transmitted to the output shaft 49 via the output shaft fixed gear 50, and the output shaft 49 can be rotated in the reverse direction at the second speed.

  Next, when the wheel loader 1 travels backward at the third speed, the reverse clutch 32 is connected to the reverse shaft 30 and the third speed change clutch 48 is connected to the third speed change shaft 46. As a result, the rotation of the input shaft 24 is shifted through the input shaft fixed gear 25, the reverse shaft fixed gear 73, the reverse shaft fixed gear 31, the reverse gear 32A, the reverse gear 32A, and the first transmission shaft fixed gear 34. This is transmitted to the third speed change gear 48A of the clutch 48.

  At this time, since the third transmission clutch 48 is connected to the third transmission shaft 46, the rotation of the third transmission gear 48 </ b> A is transmitted to the third transmission shaft fixed gear 47. Accordingly, the rotation of the third transmission shaft fixed gear 47 is transmitted to the output shaft 49 via the output shaft fixed gear 50, and the output shaft 49 can be rotated in the reverse direction at the third speed.

  Here, the power transmission device 71 according to the third embodiment reverses the rotation of the input shaft 24 and transmits it to the reverse shaft 30 as compared with the power transmission device 21 according to the first embodiment. Has been added.

  However, in the power transmission device 71, the forward shaft 26, the reverse shaft 30, the second transmission shaft 41, the third transmission shaft 46, and the reverse rotation shaft 72 are arranged around the first transmission shaft 33 so as to be input. A large space can be secured around the shaft 24. That is, as shown in FIG. 9, a fan-like shape shown by hatching between the high speed gear 29 </ b> A of the high speed clutch 29 provided on the forward shaft 26 and the reverse shaft fixing gear 73 provided on the reverse shaft 72. A large space 75 can be secured. As a result, the hydraulic pump can be disposed in the space 75 with a margin, and the degree of design freedom when the hydraulic pump is attached to the power transmission device 71 can be increased.

  Here, in the power transmission device 71 according to the third embodiment, the forward shaft 26 is arranged on a circumference centering on the input shaft 24, and the first transmission shaft 33 is on the circumference centering on the forward shaft 26. Is arranged. That is, as shown in FIG. 9, a pentagon 76 connecting the axis center of the input shaft 24, the axis center of the reverse rotation shaft 72, the axis center of the forward drive shaft 26, the axial center of the reverse drive shaft 30, and the axial center of the first transmission shaft 33. The length of each side of is constant. Further, the distance between the shaft center of the input shaft 24 and the shaft center of the first transmission shaft 33 and the distance between the shaft center of the forward shaft 26 and the shaft center of the reverse shaft 30 can be changed.

  On the other hand, the length of each side of the quadrangle 77 connecting the shaft center of the first transmission shaft 33, the shaft center of the second transmission shaft 41, the shaft center of the third transmission shaft 46, and the shaft center of the output shaft 49 is constant. The distance between the shaft center of the first transmission shaft 33 and the shaft center of the output shaft 49 and the distance between the shaft center of the second transmission shaft 41 and the shaft center of the third transmission shaft 46 can be changed. .

  Thus, for example, as in the third modification shown in FIG. 10, the shaft center of the input shaft 24, the shaft center of the reverse rotation shaft 72, the shaft center of the forward drive shaft 26, the shaft center of the reverse drive shaft 30, and the first transmission shaft 33. FIG. 9 shows an example in which the distance between the shaft center of the input shaft 24 and the shaft center of the first transmission shaft 33 is increased while keeping the length of each side of the pentagon 76 connecting the shaft center of the shaft constant. A fan-shaped space 78 that covers a wider area than the space 75 can be secured. Therefore, by using this large space 78, the degree of freedom when setting the mounting position of the hydraulic pump with respect to the power transmission device 71 can be increased. In addition, it is desired to increase the distance between the shaft center of the input shaft 24 and the shaft center of the output shaft 49 by increasing the distance between the shaft center of the input shaft 24 and the shaft center of the first transmission shaft 33. The degree of freedom in design can be increased to meet the requirements.

  In each of the above-described embodiments, the first transmission shaft 33 is provided as the first-stage transmission shaft, and the two transmission shafts of the second transmission shaft 41 and the third transmission shaft 46 are provided as the next-stage transmission shaft. The structure is illustrated. However, the present invention is not limited to this, and for example, one or three or more transmission shafts may be provided as the next-stage transmission shaft.

  Moreover, in each embodiment mentioned above, the wheel loader 1 is illustrated as a work vehicle carrying the power transmission devices 21, 61, 71. However, the present invention is not limited to this, and can be widely applied to other work vehicles such as construction vehicles such as wheel excavators, transport vehicles such as lift trucks, and agricultural vehicles such as tractors.

1 Wheel loader (vehicle)
2 Front wheel 4 Rear wheel 10 Engine (motor)
21, 61, 71 Power transmission device 24, 62 Input shaft 25 Input shaft fixed gear 26 Forward shaft 27 Forward shaft fixed gear 28 Low speed clutch 28A Low speed gear 29 High speed clutch 29A High speed gear 30 Reverse shaft 31 Reverse shaft fixed gear 32, 63 Reverse clutch 32A, 63A Reverse gear 33 First speed change shaft (first speed change shaft)
34, 35, 36 First transmission shaft fixed gear (transmission shaft fixed gear)
40 First shift clutch (shift clutch)
40A First speed change gear (speed change gear)
41 Second speed change shaft (next speed change shaft)
42, 43 Second transmission shaft fixed gear (transmission shaft fixed gear)
45 Second shift clutch (shift clutch)
45A Second gear (speed gear)
46 3rd speed change shaft (next speed change shaft)
47 Third transmission shaft fixed gear (transmission shaft fixed gear)
48 3rd shift clutch (shift clutch)
48A Third gear (speed gear)
49 Output shaft 50 Output shaft fixed gear 72 Reverse rotation shaft 73 Reverse rotation shaft fixed gear

Claims (5)

Vehicle power comprising: an input shaft that is rotated by a prime mover mounted on a vehicle; an output shaft that outputs rotation to wheels of the vehicle; and a plurality of intermediate shafts that transmit rotation of the input shaft to the output shaft. In the transmission device,
The intermediate shaft is composed of a forward travel shaft for transmitting the rotation of the input shaft, and a first transmission shaft and a next transmission shaft for shifting the rotation of the forward shaft and transmitting it to the output shaft,
The input shaft is provided with an input shaft fixed gear fixed to the input shaft and the forward shaft is provided with a forward shaft fixed gear fixed to the forward shaft,
The input shaft fixed gear and the forward shaft fixed gear are directly meshed with each other to transmit the rotation of the input shaft to the forward shaft,
The forward shaft is provided with a low speed clutch that selectively connects a low speed gear to the forward shaft, and a high speed clutch that is selectively connected to the forward shaft is selectively provided coaxially.
Each of the first-stage transmission shaft and the next-stage transmission shaft is provided with one transmission clutch for selectively connecting a transmission gear to the transmission shaft, and at least a transmission shaft fixed gear fixed to the transmission shaft. One,
The forward shaft is meshed with a low-speed gear of the low-speed clutch and a transmission-shaft fixed gear provided on the first-stage transmission shaft, or a transmission-shaft fixed provided on the high-speed gear of the high-speed clutch and the first-stage transmission shaft. It is configured to transmit rotation to the first stage transmission shaft by meshing with a gear,
The first stage transmission shaft is meshed with a transmission gear of a transmission clutch provided on the first stage transmission shaft and a transmission shaft fixed gear provided on the next stage transmission shaft, or a transmission shaft provided on the first stage transmission shaft. The rotation is transmitted to the next speed change shaft by meshing with a fixed gear and a speed change gear of a speed change clutch provided on the next speed change shaft,
The next stage transmission shaft is configured to transmit rotation to the output shaft by meshing between an output shaft fixed gear fixed to the output shaft and a transmission shaft fixed gear provided on the next stage transmission shaft. A vehicle power transmission device. The forward shaft is disposed on a circumference centered on the input shaft,
The power transmission device for a vehicle according to claim 1, wherein the first-stage transmission shaft is arranged on a circumference centered on the forward shaft. A reverse shaft for reverse travel is provided in a state arranged in parallel with the forward shaft,
The reverse shaft is provided with a reverse clutch that selectively connects a reverse gear to the reverse shaft, and is provided with a reverse shaft fixed gear fixed to the reverse shaft,
3. The reverse shaft fixed gear meshes with a forward shaft fixed gear fixed to the forward shaft, and the reverse gear of the reverse clutch meshes with a transmission shaft fixed gear of the first stage transmission shaft. The vehicle power transmission device as described. The input shaft is provided with a reverse clutch that selectively connects a reverse gear to the input shaft,
3. The vehicle power transmission device according to claim 1, wherein a reverse gear of the reverse clutch is configured to mesh with a transmission shaft fixed gear of the first stage transmission shaft. 4. A reverse shaft for reverse travel is provided in a state arranged in parallel with the forward shaft,
Providing a reverse shaft that reverses the rotation of the input shaft and transmits it to the reverse shaft in a state of being arranged in parallel with the forward shaft;
The reverse shaft is provided with a reverse clutch that selectively connects a reverse gear to the reverse shaft, and is provided with a reverse shaft fixed gear fixed to the reverse shaft,
The reverse shaft is provided with a reverse shaft fixed gear fixed to the reverse shaft,
The reverse shaft fixed gear meshes with the input shaft fixed gear fixed to the input shaft and the reverse shaft fixed gear, and the reverse gear of the reverse clutch meshes with the transmission shaft fixed gear of the first stage transmission shaft. The power transmission device for a vehicle according to claim 1 or 2.

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