JP2014098410A - Power transmission device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of components of a power transmission device for a vehicle.SOLUTION: A power transmission device 21 comprises: an input shaft 24 rotated by an engine 10 mounted to a wheel loader 1; an output shaft 48 for outputting rotation to a front wheel 2 and a rear wheel 4 of the wheel loader 1; and a high-speed shaft 27, a low-speed shaft 30, a first transmission shaft 33, a second transmission shaft 40 and a third transmission shaft 45 as intermediate shafts for transmitting rotation of the input shaft 24 to the output shaft 48. A reverse clutch 26 for connecting a backward-moving gear 26A when the wheel loader 1 is moved backward is provided to the input shaft 24. Thereby, the number of backward-moving shafts for providing the reverse clutch can be reduced by one. Also, components such as a bearing for supporting the backward-moving shaft can be made unnecessary, so as to reduce the number of components of the power transmission device 21.

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. 10-510612

  By the way, in the prior art mentioned above, it is the structure which attaches the several clutch which comprises a power transmission device one by one with respect to each intermediate shaft except an input shaft and an output shaft. As a result, the number of shafts to which the clutch is attached and the number of bearings that support the shafts increase, and the number of parts of the power transmission device increases, resulting in an increase in assembly man-hours and an increase in manufacturing costs. is there.

  On the other hand, the arrangement of the hydraulic pump with respect to the power transmission device is usually such that the output shaft of the prime mover and the input shaft of the hydraulic pump are arranged on the same axis (center PTO), the output shaft of the prime mover, and the input shaft of the hydraulic pump. Are roughly divided into configurations (side PTO) arranged in parallel.

  On the other hand, when the work vehicle is downsized, the installation space for the power transmission device inside the vehicle body is reduced, so that the output shaft of the prime mover and the input shaft of the hydraulic pump are arranged on the same axis (center PTO). ) May be difficult to adopt. In this case, it is necessary to compactly attach the hydraulic pump to the power transmission device by adopting a configuration (side PTO) in which the output shaft of the prime mover and the input shaft of the hydraulic pump are arranged in parallel.

  However, when the device arrangement space inside the vehicle body is small, it is difficult to secure a space around the input shaft of the power transmission device for arranging the input shaft of the hydraulic pump in parallel with the input shaft. There is a problem.

  The present invention has been made in view of the above-described problems of the prior art, and can reduce the number of components and secure a large space for arranging a hydraulic pump around the input shaft. 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. An intermediate shaft, and the intermediate shaft shifts the rotation of the high speed shaft and the low speed shaft to which the rotation of the input shaft is transmitted, and the high speed shaft or the low speed shaft. The present invention is applied to a vehicle power transmission device constituted by a first transmission shaft, a second transmission shaft, and a third transmission shaft that transmit to an output shaft.

  The invention according to claim 1 is characterized in that the input shaft is provided with a reverse clutch for connecting a reverse gear to the input shaft and an input shaft fixed gear fixed to the input shaft, The high-speed shaft is provided with a high-speed clutch for connecting the high-speed gear to the high-speed shaft, and is provided with a high-speed shaft fixed gear fixed to the high-speed shaft, and the low-speed shaft is provided with a low-speed gear on the low-speed shaft. And a low speed shaft fixed gear fixed to the low speed shaft, and a first speed change gear that connects a first speed change gear to the first speed change shaft. A clutch is provided, and two first transmission shaft fixed gears fixed to the first transmission shaft are provided, and a second transmission gear is connected to the second transmission shaft to the second transmission shaft. A second speed change clutch is provided, and the second speed change shaft is connected to the second speed change shaft. Two second transmission shaft fixed gears fixed to each other, and the third transmission shaft is provided with a third transmission clutch for connecting a third transmission gear to the third transmission shaft, and the third transmission shaft. There is provided one third speed change shaft fixed gear fixed to the shaft, and the input shaft fixed gear of the input shaft meshes with the high speed shaft fixed gear of the high speed shaft and the low speed shaft fixed gear of the low speed shaft. The reverse gear of the reverse clutch, the high speed gear of the high speed clutch, the low speed gear of the low speed clutch, and the third speed change gear of the third speed change clutch are one first speed change of the first speed change shaft. Meshed with the shaft fixed gear, the other first transmission shaft fixed gear of the first transmission shaft meshed with the second transmission gear of the second transmission clutch, and the first transmission gear of the first transmission clutch was Meshing with one second transmission shaft fixed gear of the second transmission shaft, Wherein the other of the second transmission shaft fixed wheel two transmission shaft 3 and the third gear shaft fixed gear of the transmission shaft, in that the meshed structure to a fixed output shaft fixed gear to the output shaft.

  According to a second aspect of the present invention, the input shaft and the output shaft are disposed on a straight line PP connecting the axes thereof, and the first transmission shaft is disposed between the input shaft and the output shaft. The high-speed shaft and the low-speed shaft are positioned between the input shaft and the first transmission shaft so as to face each other with the straight line PP therebetween, and the second transmission shaft and the first transmission shaft The three speed change shafts are disposed between the first speed change shaft and the output shaft so as to face each other with the straight line PP therebetween, and the first speed change shaft includes the input shaft and the high speed shaft. In this configuration, the low-speed shaft, the second transmission shaft, the third transmission shaft, and the output shaft are surrounded.

  According to a third aspect of the present invention, the axis of the input shaft is A, the tangent extending from the axis A of the input shaft to the outer periphery of the high-speed gear provided on the high-speed shaft is AC, and the axis A of the input shaft A space formed on the opposite side of the high speed axis and the low speed axis across the tangent line AC and the tangent line AD when a tangent line extending to the outer periphery of the low speed axis fixed gear provided on the low speed axis is defined as AD. Is configured as a device arrangement space.

  According to the first aspect of the present invention, by providing the reverse clutch on the input shaft, the reverse shaft for providing the reverse clutch can be reduced by one, and components such as a bearing for supporting the reverse shaft can be provided. It can be unnecessary. 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.

  According to the first aspect of the present invention, the rotation of the input shaft can be directly transmitted to the reverse gear by connecting the reverse gear to the input shaft by the reverse clutch. Therefore, the number of meshing of the gear is reduced compared to the case where the reverse shaft for providing the reverse clutch is provided separately from the input shaft and the rotation of the input shaft is transmitted to the reverse shaft by meshing the gear. can do. As a result, power loss due to gear meshing can be suppressed, and the fuel consumption rate (fuel consumption) of a vehicle equipped with a power transmission device can be improved.

  In addition, the reverse gear of the reverse clutch, the high-speed gear of the high-speed clutch, and the low-speed gear of the low-speed clutch mesh with one of the first transmission shaft fixed gears fixed to the first transmission shaft. The rotation of the input shaft during reverse travel is always transmitted to the second transmission shaft or the third transmission shaft via the first transmission shaft. That is, since the plurality of power transmission paths from the input shaft to the output shaft always pass through the first transmission shaft, the input shaft, the high speed shaft, the low speed shaft, the second transmission shaft, and the third transmission shaft are connected to the first transmission shaft. It can be arranged around the periphery.

  According to the invention of claim 2, the entire power transmission device is made compact by surrounding the first transmission shaft by the input shaft, the high speed shaft, the low speed shaft, the second transmission shaft, the third transmission shaft and the output shaft. Can be formed. As a result, it is possible to mount the power transmission device with a margin even on a vehicle having a small equipment arrangement space such as a small vehicle.

  According to the invention of claim 3, it is possible to secure a large device arrangement space for mounting the hydraulic pump around the input shaft. As a result, even when the configuration (side PTO) in which the input shaft of the hydraulic pump is arranged in parallel with the output shaft of the prime mover is adopted, the hydraulic pump can be attached to the vehicle power transmission device with a margin. The degree of design freedom can be increased.

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 explanatory drawing which shows the relationship between the driving state of a wheel loader, and a power transmission path | route.

  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.

  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 48 of a power transmission device 21 described later via a propeller shaft 13, and the rear axle 12 is connected to an output shaft 48 of the power transmission device 21 via a propeller shaft 14. .

  Next, the power transmission device 21 used in the present 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 (described later) provided in the casing 22, an input shaft 24, a high-speed shaft 27 as an intermediate shaft, a low-speed shaft 30, a first transmission shaft 33, and a second transmission shaft. 40, the third transmission shaft 45, the output shaft 48, the clutches 26, 29, 32, 39, 44, 47 and the gears 25, 26A, 28, 29A, 31, 32A, 34, 35, 41, 42. , 44A, 46, 47A, 49.

  Reference numeral 23 denotes a torque converter, and the torque converter 23 is connected to a crankshaft (not shown) of the engine 10. The torque converter 23 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 fixed gear 25 fixed to the input shaft 24. The input shaft fixed gear 25 includes a high-speed shaft fixed gear 28 and a low-speed shaft fixed gear 31, which will be described later. It is something that always meshes with. In this case, the input shaft 24 is arranged on a straight line PP connecting the axis (axis center) A and an axis (axis center) B of the output shaft 48 described later. The input shaft 24 and the output shaft 48 are It extends parallel to each other with an interval between the top and bottom.

  Reference numeral 26 denotes a reverse clutch provided on the input shaft 24. The reverse clutch 26 is disposed between a reverse gear 26 </ b> A provided rotatably with respect to the input shaft 24 and the input shaft 24. The reverse clutch 26 selectively connects the reverse gear 26A to the input shaft 24 by supplying and discharging clutch pressure. Further, the reverse gear 26A always meshes with one first transmission shaft fixed gear 34 described later.

  Reference numeral 27 denotes a high-speed shaft that is positioned between the input shaft 24 and a first speed change shaft 33 that will be described later, and is disposed so as to face the low-speed shaft 30 that will be described later with the straight line PP interposed therebetween. The high speed shaft 27 is used to transmit the rotation of the input shaft 24 when the wheel loader 1 travels forward at a high speed. The high-speed shaft 27 is provided with a high-speed shaft fixed gear 28 fixed to the high-speed shaft 27, and the high-speed shaft fixed gear 28 meshes with the input shaft fixed gear 25. Therefore, the high speed shaft 27 and the input shaft 24 always rotate integrally.

  Reference numeral 29 denotes a high-speed clutch provided on the high-speed shaft 27. The high-speed clutch 29 is disposed between the high-speed gear 29 </ b> A provided so as to be rotatable with respect to the high-speed shaft 27 and the high-speed shaft 27. The high speed clutch 29 selectively connects a high speed gear 29A to the input shaft 24 by supplying and discharging clutch pressure. The high speed gear 29A is always meshed with one first transmission shaft fixed gear 34 described later.

  Reference numeral 30 denotes a low-speed shaft that is located between the input shaft 24 and the first transmission shaft 33 and is disposed so as to face the high-speed shaft 27 across the straight line PP. The low speed shaft 30 is used to transmit the rotation of the input shaft 24 when the wheel loader 1 travels forward at a low speed. The low speed shaft 30 is provided with a low speed shaft fixed gear 31 fixed to the low speed shaft 30, and the low speed shaft fixed gear 31 meshes with the input shaft fixed gear 25. Therefore, the low speed shaft 30 and the input shaft 24 always rotate integrally.

  Reference numeral 32 denotes a low-speed clutch provided on the low-speed shaft 30. The low-speed clutch 32 is disposed between the low-speed gear 32 </ b> A provided so as to be rotatable with respect to the low-speed shaft 30 and the low-speed shaft 30. The low speed clutch 32 selectively connects a low speed gear 32A to the input shaft 24 by supplying and discharging clutch pressure. Further, the low speed gear 32A always meshes with one first transmission shaft fixed gear 34 described later.

  Reference numeral 33 denotes a first transmission shaft. The first transmission shaft 33 is located below the high speed shaft 27 and the low speed shaft 30 and is disposed between the input shaft 24 and an output shaft 48 described later. The first speed change shaft 33 shifts the rotation of the high speed shaft 27, the low speed shaft 30, or the input shaft 24 during reverse travel, and transmits it to the second speed change shaft 40 or the third speed change shaft 45.

  Here, the first speed change shaft 33 is provided with two first speed change shaft fixed gears 34 and 35 fixed at intervals in the axial direction, and one first speed change shaft fixed gear 34 and the other first speed change gear. The shaft fixing gear 35 has a different number of teeth. In this case, one of the first transmission shaft fixed gears 34 meshes with the low speed gear 32A of the low speed clutch 32 and also meshes with the high speed gear 29A of the high speed clutch 29 as indicated by a broken line 36 in FIG. Yes. Further, the first transmission shaft fixed gear 34 meshes with the reverse gear 26A of the reverse clutch 26 as shown by a broken line 37 in FIG. The third clutch gear 47A of the transmission clutch 47 is engaged. The other first transmission shaft fixed gear 35 meshes with a second transmission gear 44A of a second transmission clutch 44 described later.

  Reference numeral 39 denotes a first speed change clutch provided on the first speed change shaft 33. The first speed change clutch 39 and the first speed change gear 39A provided so as 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 transmission clutch 39 selectively connects the first transmission gear 39A to the first transmission shaft 33 by supplying and discharging clutch pressure. Further, the first transmission gear 39A meshes with one second transmission shaft fixed gear 41 described later.

  Reference numeral 40 denotes a second transmission shaft which is located between the first transmission shaft 33 and an output shaft 48 which will be described later, and is disposed so as to face a third transmission shaft 45 which will be described later with the straight line PP interposed therebetween. . The second transmission shaft 40 changes the rotation of the first transmission shaft 33 and transmits it to an output shaft 48 described later. Here, the second transmission shaft 40 is provided with two second transmission shaft fixing gears 41 and 42 that are fixed to the second transmission shaft 40 with an interval in the axial direction. The fixed gear 41 and the other second transmission shaft fixed gear 42 have different numbers of teeth. In this case, one second transmission shaft fixed gear 41 meshes with the first transmission gear 39A of the first transmission clutch 39, and the other second transmission shaft fixed gear 42 is indicated by a broken line 43 in FIG. Further, it is meshed with an output shaft fixing gear 49 described later.

  Reference numeral 44 denotes a second speed change clutch provided on the second speed change shaft 40. The second speed change clutch 44 and the second speed change gear 44A provided so as to be rotatable with respect to the second speed change shaft 40 and the second speed change gear. It is arranged between the shaft 40. The second speed change clutch 44 selectively connects the second speed change gear 44A to the second speed change shaft 40 by supplying and discharging clutch pressure. The second speed change gear 44 </ b> A meshes with the first speed change shaft fixed gear 35 of the first speed change shaft 33.

  Reference numeral 45 denotes a third transmission shaft that is located between the first transmission shaft 33 and the output shaft 48 and is disposed so as to face the second transmission shaft 40 with the straight line PP interposed therebetween. The third transmission shaft 45 changes the rotation of the first transmission shaft 33 and transmits it to an output shaft 48 described later. Here, the third speed change shaft 45 is provided with one third speed change shaft fixed gear 46 fixed to the third speed change shaft 45. The third speed change shaft fixed gear 46 is an output to be described later. The shaft is engaged with the shaft fixing gear 49.

  Reference numeral 47 denotes a third speed change clutch provided on the third speed change shaft 45. The third speed change clutch 47 and the third speed change gear 47A provided so as to be rotatable with respect to the third speed change shaft 45 and the third speed change gear. It is arranged between the shaft 45. The third speed change clutch 47 selectively connects the third speed change gear 47A to the third speed change shaft 45 by supplying and discharging clutch pressure. The third speed change gear 47 </ b> A meshes with the first speed change shaft fixed gear 34 of the first speed change shaft 33.

  Reference numeral 48 denotes an output shaft disposed below each of the transmission shafts 33, 40, 45. The output shaft 48 is disposed on a straight line PP connecting the axis B and the axis A of the input shaft 24. The input shaft 24 and the input shaft 24 extend in parallel to each other with an interval therebetween. The output shaft 48 transmits the rotations shifted by the transmission shafts 33, 40, 45 to the front axle 11 and the rear axle 12 of the wheel loader 1 via the propeller shafts 13, 14 shown in FIG. .

  Here, the output shaft 48 is provided with one output shaft fixing gear 49 fixed to the output shaft 48, and the output shaft fixing gear 49 is fixed to the second transmission shaft 40 of the second transmission shaft 40. The gear 42 meshes with the third transmission shaft fixed gear 46 of the third transmission shaft 45.

  In this case, the power transmission device 21 according to the present embodiment has an input shaft 24, a high-speed shaft 27, a low-speed shaft 30, a second transmission shaft 40, a third transmission shaft 45 and an output shaft 48 around the first transmission shaft 33. By arranging so as to surround the power transmission device 21, the entire power transmission device 21 can be formed compactly.

  As shown in FIG. 3, AC is a tangent line extending from the axis A of the input shaft 24 to the outer periphery of the high speed gear 29A provided on the high speed shaft 27, and is provided from the axis A of the input shaft 24 to the low speed shaft 30. Assuming that the tangent extending to the outer periphery of the low-speed shaft fixed gear 31 is AD, a large space 50 shown hatched is formed on the opposite side of the high-speed shaft 27 and the low-speed shaft 30 across the tangent AC and the tangent AD. It becomes the composition which is done.

  The power transmission device 21 according to the present embodiment has the above-described configuration. Hereinafter, the speed change operation of the power transmission device 21 during the traveling of the wheel loader 1 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. Thus, the high speed shaft 27 having the high speed shaft fixed gear 28 that meshes with the input shaft fixed gear 25 and the low speed shaft 30 having the low speed shaft fixed gear 31 that meshes with the input shaft fixed gear 25 are integrated with the input shaft 24. Rotate.

  Here, when the wheel loader 1 travels forward at the first speed, the low speed clutch 32 is connected to the low speed shaft 30 and the first speed change clutch 39 is connected to the first speed change shaft 33. For this reason, the low speed gear 32 </ b> A rotates integrally with the low speed shaft 30, and the first transmission shaft 33 rotates due to the engagement between the low speed gear 32 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the first speed change clutch 39 is connected to the first speed change shaft 33, the first speed change gear 39A rotates integrally with the first speed change shaft 33. Since the first transmission gear 39A meshes with the second transmission shaft fixed gear 41, the rotation of the first transmission gear 39A is transmitted to the second transmission shaft 40 via the second transmission shaft fixed gear 41. . As a result, the second transmission shaft fixed gear 42 rotates, and the rotation of the second transmission shaft fixed gear 42 is transmitted to the output shaft 48 by the meshing of the second transmission shaft fixed gear 42 and the output shaft fixed gear 49. The

  Therefore, when the wheel loader 1 travels forward at the first speed, the input shaft fixed gear 25, the low-speed shaft fixed gear 31, and the low-speed gears of the low-speed clutch 32 as described in the column "First Forward Speed" in FIG. 32A, the first transmission shaft fixed gear 34, the first transmission gear 39A of the first transmission clutch 39, the second transmission shaft fixed gears 41 and 42, the output shaft fixed gear 49, etc. 48 can be transmitted. In this power transmission path, the number of engagements of the gears is four.

  Next, when the wheel loader 1 travels forward at the second speed, the high speed clutch 29 is connected to the high speed shaft 27 and the first speed change clutch 39 is connected to the first speed change shaft 33. For this reason, the high speed gear 29 </ b> A rotates integrally with the high speed shaft 27, and the first transmission shaft 33 rotates due to the meshing of the high speed gear 29 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the first speed change clutch 39 is connected to the first speed change shaft 33, the first speed change gear 39A rotates integrally with the first speed change shaft 33. Since the first transmission gear 39A meshes with the second transmission shaft fixed gear 41, the rotation of the first transmission gear 39A is transmitted to the second transmission shaft 40 via the second transmission shaft fixed gear 41. . As a result, the second transmission shaft fixed gear 42 rotates, and the rotation of the second transmission shaft fixed gear 42 is transmitted to the output shaft 48 by the meshing of the second transmission shaft fixed gear 42 and the output shaft fixed gear 49. The

  Accordingly, when the wheel loader 1 travels forward at the second speed, the high speed gears of the input shaft fixed gear 25, the high speed shaft fixed gear 28, and the high speed clutch 29, as described in the column "Second Forward Speed" in FIG. 29A, the first transmission shaft fixed gear 34, the first transmission gear 39A of the first transmission clutch 39, the second transmission shaft fixed gears 41 and 42, the output shaft fixed gear 49, etc. 48 can be transmitted. In this power transmission path, the number of engagements of the gears is four.

  Next, when the wheel loader 1 travels forward at the third speed, the low speed clutch 32 is connected to the low speed shaft 30 and the second speed change clutch 44 is connected to the second speed change shaft 40. For this reason, the low speed gear 32 </ b> A rotates integrally with the low speed shaft 30, and the first transmission shaft 33 rotates due to the engagement between the low speed gear 32 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the second speed change clutch 44 is connected to the second speed change shaft 40, the rotation of the first speed change shaft 33 is changed via the second speed change gear 44A engaged with the first speed change shaft fixing gear 35. 2 is transmitted to the transmission shaft 40. As a result, the second transmission shaft fixed gear 42 rotates, and the rotation of the second transmission shaft fixed gear 42 is transmitted to the output shaft 48 by the meshing of the second transmission shaft fixed gear 42 and the output shaft fixed gear 49. The

  Accordingly, when the wheel loader 1 travels forward at the third speed, the input shaft fixed gear 25, the low-speed shaft fixed gear 31, and the low-speed gears of the low-speed clutch 32 are provided as described in the "3rd forward speed" column of FIG. 32A, the first transmission shaft fixed gears 34 and 35, the second transmission gear 44A of the second transmission clutch 44, the second transmission shaft fixed gear 42, the output shaft fixed gear 49, etc. 48 can be transmitted. In this power transmission path, the number of engagements of the gears is four.

  Next, when the wheel loader 1 travels forward at the fourth speed, the high speed clutch 29 is connected to the high speed shaft 27 and the second speed change clutch 44 is connected to the second speed change shaft 40. For this reason, the high speed gear 29 </ b> A rotates integrally with the high speed shaft 27, and the first transmission shaft 33 rotates due to the meshing of the high speed gear 29 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the second speed change clutch 44 is connected to the second speed change shaft 40, the rotation of the first speed change shaft 33 is changed via the second speed change gear 44A engaged with the first speed change shaft fixing gear 35. 2 is transmitted to the transmission shaft 40. As a result, the second transmission shaft fixed gear 42 rotates, and the rotation of the second transmission shaft fixed gear 42 is transmitted to the output shaft 48 by the meshing of the second transmission shaft fixed gear 42 and the output shaft fixed gear 49. The

  Accordingly, when the wheel loader 1 travels forward at the fourth speed, the input shaft fixed gear 25, the high-speed shaft fixed gear 28, and the high-speed gears 29 of the high-speed clutch 29, as described in the column "Fourth forward speed" in FIG. 29A, the first transmission shaft fixed gears 34 and 35, the second transmission gear 44A of the second transmission clutch 44, the second transmission shaft fixed gear 42, the output shaft fixed gear 49, etc. 48 can be transmitted. In this power transmission path, the number of engagements of the gears is four.

  Next, when the wheel loader 1 travels forward at the fifth speed, the low speed clutch 32 is connected to the low speed shaft 30 and the third speed change clutch 47 is connected to the third speed change shaft 45. For this reason, the low speed gear 32 </ b> A rotates integrally with the low speed shaft 30, and the first transmission shaft 33 rotates due to the engagement between the low speed gear 32 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the third speed change clutch 47 is connected to the third speed change shaft 45, the rotation of the first speed change shaft 33 is changed via the third speed change gear 47A engaged with the first speed change shaft fixed gear 34. It is transmitted to the three speed change shaft 45. As a result, the third transmission shaft fixed gear 46 rotates, and the rotation of the third transmission shaft fixed gear 46 is transmitted to the output shaft 48 by the meshing of the third transmission shaft fixed gear 46 and the output shaft fixed gear 49. The

  Accordingly, when the wheel loader 1 travels forward at the fifth speed, the input shaft fixed gear 25, the low-speed shaft fixed gear 31, and the low-speed gears of the low-speed clutch 32, as described in the column "5-speed forward" in FIG. 32A, the first transmission shaft fixed gear 34, the third transmission gear 47A of the third transmission clutch 47, the third transmission shaft fixed gear 46, the output shaft fixed gear 49, and the like to rotate the input shaft 24 to the output shaft 48. Can communicate. In this power transmission path, the number of engagements of the gears is four.

  Next, when the wheel loader 1 travels forward at the sixth speed, the high speed clutch 29 is connected to the high speed shaft 27 and the third speed change clutch 47 is connected to the third speed change shaft 45. For this reason, the high speed gear 29 </ b> A rotates integrally with the high speed shaft 27, and the first transmission shaft 33 rotates due to the meshing of the high speed gear 29 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the third speed change clutch 47 is connected to the third speed change shaft 45, the rotation of the first speed change shaft 33 is changed via the third speed change gear 47A engaged with the first speed change shaft fixed gear 34. It is transmitted to the three speed change shaft 45. As a result, the third transmission shaft fixed gear 46 rotates, and the rotation of the third transmission shaft fixed gear 46 is transmitted to the output shaft 48 by the meshing of the third transmission shaft fixed gear 46 and the output shaft fixed gear 49. The

  Therefore, when the wheel loader 1 travels forward at the sixth speed, the input shaft fixed gear 25, the high-speed shaft fixed gear 28, and the high-speed gears 29 of the high-speed clutch 29, as described in the column "Sixth Forward Speed" in FIG. 29A, the first transmission shaft fixed gear 34, the third transmission gear 47A of the third transmission clutch 47, the third transmission shaft fixed gear 46, the output shaft fixed gear 49, and the like to rotate the input shaft 24 to the output shaft 48. Can communicate. In this power transmission path, the number of engagements of the gears is four.

  Thus, in the power transmission device 21 according to the present embodiment, the number of times the gears mesh with each other in each power transmission path when the wheel loader 1 travels forward from the first speed to the sixth speed can be four. . On the other hand, in the power transmission device disclosed in Japanese Patent Laid-Open No. 10-510612 exemplified as the prior art, the number of meshing of the gears in the power transmission path when traveling forward at the first speed is six times, and the second speed to the sixth speed The number of meshing of the gears in the power transmission path when performing forward traveling is 4 times.

  Therefore, the power transmission device 21 according to the present embodiment can reduce the number of meshing of gears in the power transmission path when the wheel loader 1 travels forward at the first speed. Can be suppressed. As a result, it is possible to improve the fuel consumption rate (fuel consumption) when the wheel loader 1 travels forward at the first 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 26 is connected to the input shaft 24 and the first transmission clutch 39 is connected to the first transmission shaft 33. For this reason, the reverse gear 26 </ b> A rotates integrally with the input shaft 24, and the first transmission shaft 33 rotates due to the meshing of the reverse gear 26 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the first speed change clutch 39 is connected to the first speed change shaft 33, the first speed change gear 39A rotates integrally with the first speed change shaft 33. Since the first transmission gear 39A meshes with the second transmission shaft fixed gear 41, the rotation of the first transmission gear 39A is transmitted to the second transmission shaft 40 via the second transmission shaft fixed gear 41. . As a result, the second transmission shaft fixed gear 42 rotates, and the rotation of the second transmission shaft fixed gear 42 is transmitted to the output shaft 48 by the meshing of the second transmission shaft fixed gear 42 and the output shaft fixed gear 49. The

  Therefore, when the wheel loader 1 travels backward at the first speed, the reverse gear 26A of the reverse clutch 26, the first transmission shaft fixed gear 34, the first gear, as described in the column "First reverse speed" in FIG. The rotation of the input shaft 24 can be transmitted to the output shaft 48 via the first transmission gear 39A of the transmission clutch 39, the second transmission shaft fixed gears 41 and 42, the output shaft fixed gear 49, and the like. In this power transmission path, the number of meshing gears is three.

  Next, when the wheel loader 1 travels backward at the second speed, the reverse clutch 26 is connected to the input shaft 24 and the second transmission clutch 44 is connected to the second transmission shaft 40. For this reason, the reverse gear 26 </ b> A rotates integrally with the input shaft 24, and the first transmission shaft 33 rotates due to the meshing of the reverse gear 26 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the second speed change clutch 44 is connected to the second speed change shaft 40, the rotation of the first speed change shaft 33 is changed via the second speed change gear 44A engaged with the first speed change shaft fixing gear 35. 2 is transmitted to the transmission shaft 40. As a result, the second transmission shaft fixed gear 42 rotates, and the rotation of the second transmission shaft fixed gear 42 is transmitted to the output shaft 48 by the meshing of the second transmission shaft fixed gear 42 and the output shaft fixed gear 49. The

  Therefore, when the wheel loader 1 travels backward at the second speed, the reverse gear 26A, the first shift shaft fixed gear 34, the second gear 26A, the reverse clutch 26, as described in the column "Second reverse speed" in FIG. The rotation of the input shaft 24 can be transmitted to the output shaft 48 via the second speed change gear 44A of the speed change clutch 44, the second speed change shaft fixed gear 42, the output shaft fixed gear 49, and the like. In this power transmission path, the number of meshing gears is three.

  Next, when the wheel loader 1 travels backward at the third speed, the reverse clutch 26 is connected to the input shaft 24 and the third transmission clutch 47 is connected to the third transmission shaft 45. For this reason, the reverse gear 26 </ b> A rotates integrally with the input shaft 24, and the first transmission shaft 33 rotates due to the meshing of the reverse gear 26 </ b> A and the first transmission shaft fixed gear 34.

  At this time, since the third speed change clutch 47 is connected to the third speed change shaft 45, the rotation of the first speed change shaft 33 is changed via the third speed change gear 47A engaged with the first speed change shaft fixed gear 34. It is transmitted to the three speed change shaft 45. As a result, the third transmission shaft fixed gear 46 rotates, and the rotation of the third transmission shaft fixed gear 46 is transmitted to the output shaft 48 by the meshing of the third transmission shaft fixed gear 46 and the output shaft fixed gear 49. The

  Therefore, when the wheel loader 1 travels backward at the third speed, the reverse gear 26A of the reverse clutch 26, the first transmission shaft fixed gear 34, the third gear, as described in the column “3rd reverse speed” in FIG. The rotation of the input shaft 24 can be transmitted to the output shaft 48 via the third speed change gear 47A of the speed change clutch 47, the third speed change shaft fixed gear 46, the output shaft fixed gear 49, and the like. In this power transmission path, the number of meshing gears is three.

  As described above, in the power transmission device 21 according to the present embodiment, the number of times that the gears mesh with each other in each power transmission path when the wheel loader 1 travels backward from the first speed to the third speed can be three. . On the other hand, in the power transmission device disclosed in Japanese Patent Laid-Open No. 10-510612 exemplified as the prior art, the number of meshing of the gears in the power transmission path when the vehicle travels backward from the first speed to the third speed is five. .

  Therefore, the power transmission device 21 according to the present embodiment can reduce the number of meshing gears in the power transmission path when the wheel loader 1 travels backward from the first speed to the third speed. Loss can be suppressed. As a result, the fuel consumption rate (fuel consumption) when the wheel loader 1 travels backward can be improved.

  Thus, the power transmission device 21 according to the present embodiment can reduce the reverse shaft for providing the reverse clutch by one by providing the reverse clutch 26 that connects the reverse gear 26A to the input shaft 24. In addition, parts such as a bearing for supporting the reverse shaft can be eliminated. As a result, the number of parts of the power transmission device 21 can be reduced, and the number of assembly steps can be reduced, which can contribute to a reduction in manufacturing cost of the power transmission device 21.

  Moreover, the power transmission device 21 according to the present embodiment can directly transmit the rotation of the input shaft 24 to the reverse gear 26A by connecting the reverse gear 26A to the input shaft 24 by the reverse clutch 26. . Therefore, for example, compared with a case where a reverse shaft for providing a reverse clutch is provided separately from the input shaft 24 and the rotation of the input shaft 24 is transmitted to the reverse shaft by meshing of the gear, the meshing of the gear is performed. The number of times can be reduced. As a result, power loss due to gear meshing can be suppressed, and the fuel consumption rate (fuel consumption) of the wheel loader 1 equipped with the power transmission device 21 can be improved.

  Further, in the power transmission device 21 according to the present embodiment, the reverse gear 26A of the reverse clutch 26, the high speed gear 29A of the high speed clutch 29, and the low speed gear 32A of the low speed clutch 32 are fixed to the first transmission shaft 33. One of the first transmission shaft fixed gears 34 is meshed. As a result, the rotation of the input shaft 24 during forward traveling and reverse traveling of the wheel loader 1 is always transmitted to the second transmission shaft 40 or the third transmission shaft 45 via the first transmission shaft 33. . That is, the plurality of power transmission paths from the input shaft 24 to the output shaft 48 always pass through the first transmission shaft 33. Therefore, the input shaft 24, the high speed shaft 27, the low speed shaft 30, the second speed change shaft 40, and the third speed change shaft 45 can be arranged around the first speed change shaft 33.

  Therefore, the input shaft 24, the high speed shaft 27, the low speed shaft 30, the second speed change shaft 40, the third speed change shaft 45, and the output shaft 48 can be disposed so as to surround the first speed change shaft 33. As a result, the entire power transmission device 21 can be formed compactly, and the power transmission device 21 can be mounted in the rear vehicle body 5 of the wheel loader 1 with a margin.

  On the other hand, as shown in FIG. 3, the tangent line AC extending from the axis A of the input shaft 24 to the outer periphery of the high speed gear 29A provided on the high speed shaft 27 and the axis A of the input shaft 24 provided on the low speed shaft 30 are provided. A large space 50 serving as a device arrangement space can be secured on the opposite side of the high speed shaft 27 and the low speed shaft 30 across the tangent line AD extending to the outer periphery of the low speed shaft fixed gear 31. As a result, for example, when adopting a configuration (side PTO) in which the input shaft (none of which is shown) of the hydraulic pump is arranged in parallel with the output shaft of the engine 10, the hydraulic pump is arranged in the space 50 with a margin. Can do. Therefore, the degree of freedom in design when attaching the hydraulic pump to the power transmission device 21 can be increased.

  In the above-described embodiment, the wheel loader 1 is illustrated as a work vehicle on which the power transmission device 21 is mounted. However, the present invention is not limited to this, and can be widely applied to power transmission devices mounted on 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 Power transmission device 24 Input shaft 25 Input shaft fixed gear 26 Reverse clutch 26A Reverse gear 27 High-speed shaft (intermediate shaft)
28 High-speed shaft fixed gear 29 High-speed clutch 29A High-speed gear 30 Low-speed shaft (intermediate shaft)
31 Low-speed shaft fixed gear 32 Low-speed clutch 32A Low-speed gear 33 First transmission shaft (intermediate shaft)
34 One first transmission shaft fixed gear 35 The other first transmission shaft fixed gear 39 First transmission clutch 39A First transmission gear 40 Second transmission shaft (intermediate shaft)
41 One second transmission shaft fixed gear 42 The other second transmission shaft fixed gear 44 Second transmission clutch 44A Second transmission gear 45 Third transmission shaft (intermediate shaft)
46 Third transmission shaft fixed gear 47 Third transmission clutch 47A Third transmission gear 48 Output shaft 49 Output shaft fixed gear

Claims (3)

An input shaft that is rotated by a prime mover mounted on a vehicle, an output shaft that outputs rotation to a wheel of the vehicle, and a plurality of intermediate shafts that transmit the rotation of the input shaft to the output shaft, A high-speed traveling high-speed shaft to which the rotation of the input shaft is transmitted and a low-speed traveling low-speed shaft; a first transmission shaft that shifts rotation of the high-speed shaft or the low-speed shaft and transmits the rotation to the output shaft; In the vehicle power transmission device configured by the two transmission shafts and the third transmission shaft,
The input shaft is provided with a reverse clutch for connecting a reverse gear to the input shaft, and is provided with an input shaft fixed gear fixed to the input shaft,
The high-speed shaft is provided with a high-speed clutch for connecting a high-speed gear to the high-speed shaft, and is provided with a high-speed shaft fixed gear fixed to the high-speed shaft,
The low-speed shaft is provided with a low-speed clutch for connecting a low-speed gear to the low-speed shaft, and a low-speed shaft fixed gear fixed to the low-speed shaft is provided.
The first transmission shaft is provided with a first transmission clutch for connecting a first transmission gear to the first transmission shaft, and two first transmission shaft fixed gears fixed to the first transmission shaft. Provided,
The second transmission shaft is provided with a second transmission clutch for connecting a second transmission gear to the second transmission shaft, and two second transmission shaft fixed gears fixed to the second transmission shaft. Provided,
The third transmission shaft is provided with a third transmission clutch for connecting a third transmission gear to the third transmission shaft, and one third transmission shaft fixed gear fixed to the third transmission shaft. Provided,
The input shaft fixed gear of the input shaft meshes with the high speed shaft fixed gear of the high speed shaft and the low speed shaft fixed gear of the low speed shaft,
The reverse gear of the reverse clutch, the high speed gear of the high speed clutch, the low speed gear of the low speed clutch, and the third speed change gear of the third speed change clutch are one first speed change shaft of the first speed change shaft. Mesh with fixed gear,
The other first transmission shaft fixed gear of the first transmission shaft meshes with the second transmission gear of the second transmission clutch;
A first transmission gear of the first transmission clutch meshes with one second transmission shaft fixed gear of the second transmission shaft;
The other second transmission shaft fixed gear of the second transmission shaft and the third transmission shaft fixed gear of the third transmission shaft mesh with an output shaft fixed gear fixed to the output shaft. A vehicle power transmission device. The input shaft and the output shaft are arranged at intervals on a straight line PP connecting the axes of each other,
The first transmission shaft is disposed between the input shaft and the output shaft;
The high speed shaft and the low speed shaft are located between the input shaft and the first transmission shaft so as to face each other with the straight line PP therebetween,
The second speed change shaft and the third speed change shaft are located between the first speed change shaft and the output shaft, and are disposed so as to face each other with the straight line PP therebetween.
2. The vehicle according to claim 1, wherein the first transmission shaft is configured to be surrounded by the input shaft, the high speed shaft, the low speed shaft, the second transmission shaft, the third transmission shaft, and the output shaft. Power transmission device. The input shaft axis is A, the tangent line extending from the input shaft axis A to the outer periphery of the high speed gear provided on the high speed shaft is AC, and the input shaft axis A is provided on the low speed shaft. When the tangent extending to the outer periphery of the low-speed shaft fixed gear is AD,
The vehicle power transmission device according to claim 2, wherein a space formed on the opposite side of the high speed axis and the low speed axis with the tangent line AC and the tangent line AD is secured as a device arrangement space.

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